Patent Application
20140276013
1. Field
The present application relates to optical tomography systems and sensors and related apparatus and methods.
2. Related Art
Diagnostic instruments for monitoring properties of the brain include magnetic resonance imaging (MRI) devices, computed tomography (CT) devices, microdialysis devices, transcranial Doppler devices, oxygen catheters, x-ray devices, electroencephalography devices, positron emission tomography devices, single-photon emission computed tomography (SPECT) devices, magnetoencephalography devices, ultrasound devices, and optically-based instrumentation. Some such instruments are placed in proximity to the patient's head. Optically-based sensors for analyzing medical patients are known and optical tomography is a known technique for optically inspecting a specimen.
According to an aspect of the technology, an optical sensor is provided, comprising a plurality of optical sources and a plurality of optical detectors, wherein the plurality of optical sources and the plurality of optical detectors collectively form an array and wherein at least first and second optical detectors of the plurality of optical detectors are configured to receive optical signals from at least a first optical source of the plurality of optical sources. The optical sensor further comprises analog receive circuitry configured to receive an analog signal from the first optical detector of the plurality of optical detectors, and an analog-to-digital converter (ADC) configured to convert the analog signal to a digital signal. The plurality of optical sources, plurality of optical detectors, analog receive circuitry, and ADC are, in some embodiments, at least partially encapsulated in a flexible support structure configured to conform to a subject such that the first and second optical detectors of the plurality of optical detectors are configured to receive optical signals from the first optical source of the plurality of optical sources that pass through the subject.
According to an aspect of the technology, a system is provided, comprising and optical sensor of the type described above, a host coupled to the optical sensor by a digital communication line, and a central unit coupled to the host. The central unit may be configured to control display of data representative of optical signals received by the plurality of optical detectors from the plurality of optical sources.
According to an aspect of the technology, an optical apparatus is provided, comprising a plurality of optical sources, and a plurality of optical detectors. The plurality of optical sources and plurality of optical detectors may be arranged in combination in an array and disposed on a flexible substrate to form a flexible array. The flexible array may be configured to conform to a subject. The optical apparatus may have an outer surface configured to contact the subject such that the plurality of optical sources is configured to direct optical radiation toward the subject and the plurality of optical detectors is configured to detect the optical radiation after passing through the subject. At least one optical source of the plurality of optical sources may have an emission point disposed within approximately 3 mm of the outer surface of the optical apparatus. At least one optical detector of the plurality of optical detectors may have a detection point disposed within approximately 3 mm of the outer surface of the optical apparatus.
According to an aspect of the technology, an optical sensor is provided, comprising a plurality of optical sources, including a first optical source disposed at a first position of the optical sensor and configured to emit a first plurality of wavelengths and a second optical source disposed at a second position of the optical sensor and configured to emit a second plurality of wavelengths different than the first plurality of wavelengths. The optical sensor further comprises a plurality of optical detectors, including a first optical detector disposed at a third location of the optical sensor and configured to detect the first plurality of wavelengths from the first optical source and the second plurality of wavelengths from the second optical source. The plurality of optical sources and the plurality of optical detectors collectively form an array. The optical sensor further comprises analog receive circuitry configured to receive an analog signal from the first optical detector of the plurality of optical detectors, and an analog-to-digital converter (ADC) configured to convert the analog signal to a digital signal. The plurality of optical sources, plurality of optical detectors, analog receive circuitry, and ADC are, in some embodiments, at least partially encapsulated in a flexible support structure configured to conform to a subject.
Various aspects and embodiments of the application will be described with reference to the following figures. It should be appreciated that the figures are not necessarily drawn to scale. Items appearing in multiple figures are indicated by the same reference number in all the figures in which they appear.
Aspects of the present application relate to systems and methods for using optical tomography to provide and/or evaluate a condition or characteristic of a subject of interest, such as the brain of a human patient. Such evaluation may be desirable in various circumstances, such as when dealing with medical patients (which represent one example of a subject) who have suffered brain trauma, who suffer from a neurological disease (e.g., stroke), or for whom it is otherwise desirable to monitor the condition of the brain, as non-limiting examples. In some such circumstances, evaluation of the subject's condition may not be easily achieved due to physical constraints, such as the physical placement of the subject, the physical condition of the subject (e.g., open wounds, etc.), positioning of various medical equipment relative to the subject (e.g., surgical tools, other monitoring equipment, etc.), and/or obstacles in the form of hair or other objects on the target area of interest of the subject (e.g., the subject's head), among others. In some embodiments, the subject may not be able to be moved to a room having an MRI, CT scanner, x-ray machine, or other diagnostic instrument because, for example, the subject (e.g., a medical patient) may rely on life supporting systems which are incompatible with such imaging devices. Moreover, in some such circumstances, the subject may be unable to tolerate physically invasive evaluation tools or movement of the head. Such circumstances can arise, for example, in the context of neurocritical care environments. Further still, in some such circumstances long term monitoring of the subject may be desirable compared to diagnostic tools which typically provide information about only a short time (e.g., a point in time).
Accordingly, aspects of the present application provide systems for performing minimally- or non-invasive diffuse optical tomography (DOT) measurements of a subject suitable for providing information regarding one or more physical conditions or characteristics of a target portion of the subject (e.g., the subject's brain including the surface thereof, limb, torso, skin flap, organ, breast, tissue exposed by surgery, or other region of interest). Additionally or alternatively, the systems may be used to analyze such information, for example to assess a condition or characteristic of the subject (e.g., to assess a condition of the subject's brain, to assess a transplanted limb or organ, etc.). In some such embodiments, the monitoring may be performed bedside in a medical facility.
In some embodiments, the systems include a sensor (e.g., an optical sensor) configured to be placed on a subject's head while being minimally obtrusive. Optical data may be collected regarding (and in some embodiments, representing) multiple regions of the subject's brain, and in some embodiments may be collected on a continuous (or substantially continuous) basis. The data may be indicative of one or more physical conditions and/or may be suitably processed to allow for analysis (e.g., visual display) of one or more physical (e.g., biological) conditions of interest, such as oxygenated hemoglobin (HbO2) and de-oxygenated hemoglobin (HbR) levels, total hemoglobin levels (tHb), or other metrics of interest. In some embodiments, a map of tissue oxygen saturation (StO2) levels in the brain, in muscular tissue, or in any other target area of interest, may be generated. The systems may thus facilitate analysis of a subject's brain, particularly in neurocritical care environments, among others.
In those embodiments in which oxygenated, de-oxygenated, and/or total hemoglobin levels are determined, such determination may be made in any suitable manner. For example, in biological tissue, absorption of light at wavelengths in the 600 to 900 nm range depends primarily on hemoglobin, lipids, melanin and water. Absorption due to oxygenated and deoxygenated hemoglobin varies with the wavelength throughout this range in consistent and predictable ways. Thus, light absorption measurements at two or more wavelengths may be used to estimate concentrations of oxygenated and de-oxygenated hemoglobin. In a particular tissue, absorption may be estimated from detected light intensity at two or more distances from a light source. From estimates of the optical absorption at two or more wavelengths, concentrations of oxygenated and de-oxygenated hemoglobin may be estimated. Total hemoglobin concentration may be calculated as a sum of the oxygenated and deoxygenated hemoglobin concentrations.
In some embodiments, systems for performing DOT analysis of a subject's head may include multiple, physically distinct components, though not all embodiments are limited in this respect. For example, a sensor may be provided on the subject's head and a support may be provided for holding the sensor to the subject. In some embodiments, the support may hold or position the sensor relative to a subject, and thus in some embodiments the support may be considered a holder or positioner. In those embodiments in which the support holds the sensor to a subject's head, the support may be referred to as a “headpiece.” In some scenarios, more than one sensor may be provided, for example to measure and compare biological conditions of different regions/areas of interest. One or more control components for controlling the sensor may be provided remotely from the sensor. A non-limiting example of such a system according to an aspect of the present application is shown in
System 100 includes a support 102, one or more sensors 104 (two of which are shown), a host module 106 (which may also be referred to herein simply as a “host”), and a central unit 108 (which may also be referred to herein as a “master”). The support 102 may support the sensor(s) 104 in relation to the head 110 of a subject (e.g., a medical patient). Thus, the support 102 may represent a headpiece in some embodiments. The system may irradiate the subject's head with optical emissions from the sensor 104 and detect and process optical emissions received from the head, including the original optical emissions emitted by the sensor 104 and/or optical emissions triggered inside the subject in response to original optical emissions from the sensor 104. The host module 106 and central unit 108 may perform various functions, including controlling operation of the sensor 104 and processing the collected data.
The system 100 may be used to provide and/or analyze information relating to various physical conditions or characteristics. For example, the intensity, phase, and/or frequency of optical signals detected by an optical detector may be used to provide information relating to various physical conditions or characteristics. In some embodiments, the system 100 may be used to provide and/or analyze information relating to absorption (within a given spectral range) of endogenous biological chromophores, such as: oxygenated hemoglobin; de-oxygenated hemoglobin; lipids; water; myoglobin; bilirubin; and/or cytochrome C oxidase. In some embodiments, the system may monitor oxygenated and de-oxygenated hemoglobin concentrations in tissue, and absorption by the other listed chromophores may be considered in determining the oxygenated and de-oxygenated hemoglobin absorptions.
In some embodiments, the system 100 may measure absorption by exogenous chromophores, such as indocyanine green (ICG) or other biologically compatible near infrared (NIR) absorbing dyes or optical tracers, which may be introduced to the subject (e.g., human tissue) in any suitable manner.
In some embodiments, alternatively or in addition to measuring absorption properties, the system 100 may measure scattering properties of a subject, such as scattering properties of biological tissue. Measured absorption properties and scattering properties may allow for determination of oxygenated hemoglobin concentration and deoxygenated hemoglobin concentration, from which one may calculate total hemoglobin concentration and tissue oxygen saturation (HbO2)/(tHb)).
In some embodiments, the system 100 may be used to determine (or partially measure) physiological indicators (or measurable quantities leading to determination of such indicators) including arterial and venous oxygen saturation, oxygen extraction fraction, cerebral blood flow, cerebral metabolic rate of oxygen, and/or regional cerebral blood flow, among others.
In some embodiments, the system may be configured to measure any of the previously described indicators or characteristics spatially. Thus, one or more images may be generated from the resulting data. In some embodiments, multiple areas or regions of a subject may be imaged substantially simultaneously (which includes simultaneous imaging), thus allowing comparison of image results for the different areas or regions.
The system 100 may have dynamic measurement properties that provide sufficient (in the physiological realm) time resolution to resolve functional (stimulus-response) activation as well as track optical tracer concentration changes. The system may be suitable for long-term real-time measurements of changes in optical absorption allowing for continuous subject monitoring (e.g., continuous monitoring of a medical patient) over extended periods and allowing for the measurement and tracking of treatment response.
The support 102, sensor 104 (which in some embodiments may be referred to as a sensor array), host module 106 and central unit 108 of system 100 may take various forms, non-limiting examples of which are described further below. The sensor 104 may be an optical sensor (generating and/or receiving optical signals) and may include suitable components for performing DOT measurements (using near infrared spectroscopy (NIRS) techniques, for example), including one or more optical sources and/or one or more optical detectors. As shown, the sensor 104 may be configured to optically couple to a subject's head (or other region of interest of a subject). In some embodiments, the sensor 104 may be flexible to conform to the subject's head.
The support 102 may hold or otherwise support the sensor 104 against the subject's head, and may have any suitable construction for doing so. In some embodiments, the support 102 may be formed of a flexible material to allow it to conform to the subject's head and/or to the sensor 104. As shown, in some embodiments the support 102 may be configured to minimize coverage of the subject, thus allowing (unimpeded) physical access to the subject over as large an area as possible. For example, as shown in
Moreover, a support need not be used in all embodiments. For example, a sensor 104 may be held in a desired relation relative to a subject using a hand-held device (e.g., a handle coupled to the sensor 104). In such embodiments, the hand-held device may take any suitable form. Non-limiting examples are illustrated and described below in connection with
The host module 106 may be coupled to the sensor 104 by a cabled or wireless connector 114 and may perform various functions with respect to the sensor 104, including controlling operation of the sensor 104 to at least some extent. For example, the host module may communicate control signals to the sensor 104 to control activation of the sensor 104 and/or may receive signals from the sensor 104 representative of the optical signals detected by the sensor 104. The host module 106 may also serve as a communication relay between the sensor 104 and the central unit 108, for example in some embodiments integrating or grouping data (e.g., data packets) from multiple sensors 104 into a frame prior to sending to the central unit 108. The host module may be implemented in any suitable form.
The central unit 108, which may be implemented in any suitable form, may be coupled to the host module by a cabled or wireless connection 116 and may perform various control functionality for the system. For example, the central unit 108 may include a user interface via which a user (e.g., a doctor, clinician, or other user) may select the conditions of a test or monitoring event to be performed on the subject. The central unit 108 may provide to the host module 106 suitable control signals relating to the selected test or monitoring event. The host module 106 may, in turn, provide suitable control signals to the sensor 104 to cause production and collection of optical emissions. Collected signals may then be provided to the central unit 108 via the host module 106, and the central unit may, for example, perform post processing on the signals. In some embodiments, the central unit 108 may control display of collected information, for example in textual and/or graphical form on a display 112.
While the system 100 of
In some embodiments, an optical system such as system 100 may be used in connection with other sensing modalities. For example, the optical system may be used in combination with electroencephalography (EEG). Such a combination may facilitate, for example, monitoring of brain electrical activity as well as tissue perfusion. Thus, the system 100 is not limited to being used on its own.
According to an aspect of the application, an optical sensor is provided that includes a plurality of optical sources and a plurality of optical detectors. The optical sources and optical detectors may be formed on or otherwise connected by a common substrate, which may be flexible in some embodiments, allowing the optical sensor to be placed in contact with, and to conform to, a subject of interest or portion thereof (e.g., a subject's head). The optical sensor may also include analog and/or digital circuitry (e.g., control circuitry) for controlling collection of data by the optical sensor. The optical sensor may communicate digitally (e.g., via a digital cabled connection) to one or more remote components for receiving control signals and providing collected data to the remote components.
According to an aspect of the application, an optical structure includes a plurality of optical sources disposed on flexible circuit board strips and a plurality of optical detectors disposed on flexible circuit board strips. The flexible circuit board strips may be positioned relative to each other such that the optical sources and optical detectors collectively form an optical array. For example, the flexible circuit board strips may be interspersed or interleaved with each other. Circuitry, including analog and/or digital circuitry may also be disposed on flexible circuit board strips coupled to the flexible circuit board strips on which the optical sources and optical detectors are disposed. The entire structure may be, in some embodiments, partially or completed encapsulated in a supporting structure, such as in a flexible rubber material.
According to an aspect of the application, an optical apparatus includes an array of optical sources and optical detectors provided on a common substrate configured to contact (or otherwise be disposed in proximity to) a subject, such as a patient. The optical sources and/or optical detectors may be close to the surface of the subject, which may serve to minimize loss of light intensity as optical signals pass from the optical sources through the subject to the optical detectors. For example, in some embodiments an optical source may be positioned such that it has an emission point located within approximately 10 mm of an outer surface of the optical apparatus, within approximately 3 mm of an outer surface of the optical apparatus arranged for positioning adjacent the subject's surface, within 2 mm of the outer surface, within 1 mm of the outer surface, or any other suitable distance from the outer surface. In some embodiments an optical detector may have a detection point disposed within approximately 10 mm of the outer surface of the optical apparatus, within 3 mm of the outer surface of the optical apparatus, within 2 mm of the outer surface, within 1 mm of the outer surface, or any other suitable distance from the outer surface.
According to an aspect of the application, a method of operating an optical sensor is provided. The optical sensor may include a plurality of optical sources and a plurality of optical detectors. The optical sources may be controlled to irradiate a subject (e.g., a patient) with optical signals. The optical signals may pass through the subject and be detected by the optical detectors upon exit from the subject. In some embodiments, the optical signals from the sources may enter the subject and cause an optical emission within the subject that is then detected by the detectors. The optical detectors may generate analog signals representative of the detected optical signals (whether representing the original optical signals from the optical sources after passing through the subject or optical signals triggered internally to the subject in response to the optical signals from the optical sources), and in some embodiments the analog signals may be converted to digital signals on the optical sensor. The resulting digital signals may be transmitted to a remote component for further processing.
Aspects of the application are directed to structures for optical components including optical sources and optical detectors. In some embodiments, a similar structure may be implemented for both optical sources and optical detectors, but with optical sources including a different type of optically active element than optical detectors. In some embodiments, an optical component may include a columnar structure with an upper surface on which the optically active element, be it an optical emitter or a detecting element, is disposed. The columnar structure may include a columnar printed circuit board, and may include electrical connections for connecting to the optically active element such that electrical signals can be provided to and/or received from the optically active element.
According to an aspect of the application, an optical component is provided, which may be either an optical source or an optical detector. The optical component may be configured to have an emission/detection point raised above surrounding structures, and may in some embodiments be configured to facilitate working through (or penetrating) obstacles such as hair. In some embodiments, the optical component includes a columnar printed circuit board (PCB) having an upper surface with conductive traces thereon and having a height between approximately 2 mm and approximately 20 mm (e.g., 5 mm, 10 mm, 15 mm, or any other suitable height). The upper surface may be higher than surrounding structures. An optically active element (e.g., an optical emitter, such as a light emitting diode (LED), or an optical detecting element, such as a photodetector) may be disposed on the upper surface of the columnar PCB and electrically coupled to the conductive traces of the columnar PCB.
In some embodiments, the optically active element may be covered by one or more components. For example, an optically transparent or transmissive cover may be included with the optical component to cover the optically active element. Any such cover may be transparent (or, in some embodiments, transmissive) to wavelengths emitted by or detected by the optically active element. In some embodiments, a sleeve may be provided at least partially around the columnar PCB and the optically transparent cover. The sleeve may serve one or more functions, such as being a support (e.g., to maintain relative positioning of two or more of the constituent parts of the optical component), serving as an electrical connection (e.g., a conductive pathway), and/or performing a light blocking or isolation function.
According to an aspect of the application, an optical sensor for use in an optical tomography system is provided. The optical sensor may include one or more optical components of a type described herein. In some embodiments, multiple optical components (e.g., multiple optical sources and/or multiple optical detectors) may be provided with the optical sensor, and may be arranged in an array or other suitable configuration.
As described previously, in some embodiments an optical component may be configured to penetrate (or extend through) obstacles (e.g., hair). For example, when using optical tomography sensors to evaluate a medical patient, the optical component may need to extend through hair or other obstacles to contact the patient. In some embodiments, the optical component may be sized (e.g., having a particular cross-sectional area, a particular width, etc.) to facilitate extending through such obstacles.
The aspects and embodiments described above, as well as additional aspects and embodiments, are described further below. These aspects and/or embodiments may be used individually, all together, or in any combination of two or more, as the application is not limited in this respect.
An optical system for using DOT to analyze a subject, such as system 100 of
The optical sensor 200 includes a plurality of optical sources 202 (shown with dotted fill), totaling ten in all, and a plurality of optical detectors 204, totaling eighteen in all. Collectively, the optical sources 202 and optical detectors 204 form an array in the non-limiting embodiment illustrated, and thus the optical sensor 200 may alternatively be referred to herein as a sensor array. In particular, in the non-limiting example of
In some embodiments, the optical sensors 200 may be considered to be pads or patches to be affixed to or otherwise held in proximity to a desired area of the subject. However, not all embodiments of sensor arrays described herein are limited in this respect.
Each of the three optical sensors 200 in
As can be seen in
As described already, any suitable number and configuration of optical sensors may be used. The use of three optical sensors as shown in
Also worth noting with respect to
As should also be appreciated from
As shown, the optical sensor 200 includes an outer surface 312 configured to contact the subject's head 110. In the non-limiting embodiment illustrated, the outer surface 312 corresponds to the outer surfaces of optical source 202 and optical detector 204, though not all embodiments are limited in this respect. The optical source 202 includes an active emitter (e.g., an LED) having an emission point 314 (e.g., the emission point 314 may correspond to the location of the LED within the optical source 202), while the optical detector 204 (e.g., a photodetector) has a detection point 316 (e.g., the detection point 316 may correspond to the location of the photodetector within the optical detector 204). The emission point 314 and/or detection point 316 may be separated from the subject's head 110 by a distance d1. In some embodiments, d1 may be small. For example, d1 may be less than approximately 10 mm, less than approximately 5 mm, less than approximately 3 mm, less than approximately 2 mm, less than approximately 1 mm, or any other suitable distance. By configuring the optical sensor in some embodiments such that the distance d1 is small, the light intensity lost as the optical signals pass from the optical sources into the subject and out to the optical detectors may be minimized. Furthermore, as shown, the subject may be impressed (at least slightly) by the optical source 202 and/or optical detector 204 which may improve the transmission of signals between the optical source 202 and the subject 110, and between the subject 110 and the optical detector 204. The distance d1 need not be the same for the optical source 202 and the optical detector 204 in all embodiments. Rather, the emission point 314 and detection point 316 may be positioned at different distances from the outer surface 312 of the optical sensor.
Moreover, it should be appreciated that while
The optical sources 202 and optical detectors 204 may have any suitable constructions. For example, each of the optical sources 202 and detectors 204 may include a transparent cover 318, for example being a lens formed of a resin or other suitable optically transparent material. In some embodiments, the transparent cover 318 may function as a light guide, and thus be alternatively referred to as a light guide (e.g., a shaped light guide), or in some embodiments a lens. Its shape may be selected to maximize the light intensity entering the subject from the optical source. The transparent cover 318 may be formed of a hard (e.g., non-compressible, such as polycarbonate) or soft (e.g., compressible, such as silicone) material. In some embodiments, a soft material may be selected to improve comfort for the subject, since the optical sources may be forced against the surface of the subject (e.g., being placed in contact with a patient's head).
The optical sources 202 may optionally include a filter 322, and the optical detectors 204 may optionally include a filter 324. Such filters may be integrated with the transparent covers 318 (e.g., being a single component). Other components may optionally be included.
Thus, in some embodiments, the only thing between the emission point 314 and the subject may be a filter and a lens/cover (e.g., transparent cover 318), and likewise the only thing between the detection point 316 and the subject may be a filter and a lens. Other constructions are possible.
As described previously, and as illustrated in
Detection of an optical signal from an optical source with multiple optical detectors may be beneficial for providing an increased amount of data about a subject as opposed to if only a single optical detector detected the optical signals produced by a given optical source. The greater the amount of data, the more robust the analysis of the subject may be. However, greater signal processing (and therefore signal processing resources) may also be needed. As a non-limiting example, assuming that first, second, and third nearest neighbor optical detectors in
The optical sources 202 of the optical sensor 200 may emit any suitable wavelengths of optical radiation. As previously described, in some embodiments the optical sources may operate in the infrared spectrum, and in some embodiments within the NIR (near infrared) spectrum. In some embodiments, the optical sources may operate in the visible (or a portion thereof) through NIR spectrum. In some embodiments, the optical sources may emit wavelengths in the visible spectrum. As non-limiting examples, each of the optical sources may emit wavelengths between approximately 500 nm and approximately 1,100 nm, between approximately 600 nm and approximately 1,000 nm, between approximately 650 nm and approximately 950 nm, a wavelength of approximately 650 nm, approximately 700 nm, approximately 750 nm, approximately 800 nm, approximately 850 nm, approximately 900 nm, approximately 920 nm, approximately 925 nm, approximately 950 nm, or any other suitable wavelengths.
Also, in some embodiments the optical sources of the optical sensor 200 need not all emit the same wavelengths. For example, a first optical source may emit a first wavelength (e.g., approximately 650 nm) and a second optical source may emit a second wavelength (e.g., approximately 800 nm). The use of multiple wavelengths may facilitate detection of various quantities of interest with respect to the subject, since different wavelengths of the radiation may behave differently when passing through the subject.
The optical detectors may detect the wavelengths emitted by the optical sources. In some embodiments, all the optical detectors may be capable of detecting any of the wavelengths emitted by any of the optical sources. In such embodiments, all the optical detectors may be substantially identical to each other. However, in some embodiments different optical detectors may be capable of detecting different wavelength ranges from each other.
In some embodiments, the optical sensor 200 may be used to provide information about the concentration of oxygenated or deoxygenated hemoglobin (or both) in tissue of a subject (e.g., the concentration of oxygenated and/or deoxygenated hemoglobin in a subject's brain, muscle or other tissues). Thus, the wavelengths of radiation used by the optical sensor 200 may be selected to facilitate collection of such information. In some embodiments, the wavelengths utilized by the optical sensor 200 may be approximately equally dispersed over the range from approximately 650 nm to approximately 950 nm. A broader spectrum may be used at the higher end of this range, in some embodiments. A narrower range (i.e., narrower than 650 nm to 950 nm) may be used in some embodiments, for example those embodiments in which only two to four wavelengths are to be used. In some embodiments, only two wavelengths may be used, with one below the isosbestic point of hemoglobin, which is about 800 nm, and one above (e.g., one wavelength below approximately 765 nm and one wavelength above approximately 830 nm).
As described previously, in some embodiments the optical sources and optical detectors of an optical sensor may be mechanically coupled together, for example to facilitate relative positioning and spacing of the components with respect to a subject. In the example of
In some embodiments, the support structure 206 may be flexible, for example, being able to flex about one or more axes (e.g., in two orthogonal directions), such as about the x- and y-axes in
In some embodiments, including some of those in which the support structure 206 is flexible, the support structure 206 may be formed of an optically opaque material to optically isolate the optical sources and detectors from each other, as previously described in connection with
In some embodiments, the support structure 206 may be formed of a substantially optically transparent material. In such embodiments, if it is desired to prevent optical signals from the optical sources passing through the transparent material and being detected by the optical detectors of the optical sensor, other techniques (other than using an opaque support structure 206) may be used to prevent such signal detection. For example, a liner of the types illustrated and described herein may be used, as will be described further below in connection with
In some embodiments, the support structure 206 may be formed of a material that is not electrically conductive (e.g., an electrical insulator, such as rubber or resin).
As shown in
In some embodiments, the bottom side of the support structure 206 may have one or more features to provide the support structure with increased flexibility. For example, the bottom side of the support structure 206 may include grooves, channels, dimples, indentations, or other suitable features to increase the flexibility of the support structure 206.
The optical sensor 200 may also include control circuitry (or control electronics) for controlling operation of the optical sources 202 and/or optical detectors 204, including analog and/or digital circuitry. The circuitry may take any suitable form, some examples of which are described in further detail below. When such circuitry is included, it may be positioned at any suitable location(s) with respect to the optical sensor. For example, the circuitry may be grouped into modules positioned at the periphery (e.g., along a single edge) of the optical sensor. Placement of the circuitry of the optical sensor at an edge may minimize or simplify the placement of electrical connections for communicating between the optical sensor and remote components of an optical system. As a result, access to a subject (e.g., a patient) may be maximized when the optical sensor 200 is in place. Referring to
Various types of circuitry may be included in connection with or as part of the optical sensor 200. The optical sources 202 and/or optical detectors 204 may be analog components and thus analog circuitry may be included with the optical sensor 200. For example, the optical sources 202 may be light emitting diodes (LEDs), and therefore it may be desirable for the optical sensor 200 to include analog drive circuitry (e.g., an LED controller) configured to control, at least in part, one or more (e.g., all) of the LEDs. For example, the drive circuitry may control the ON/OFF state of the optical sources (and therefore the duration of the optical signals emitted by the optical sources), the frequency modulation of the optical sources and/or the emission intensity and power of the optical sources (e.g., by controlling the current to the optical sources). The optical detectors may be photodetectors (e.g., photodiodes, phototransistors, or any other suitable type of photodetectors) and may be coupled to analog receive circuitry, such as an amplifier, a filter, or other signal conditioning circuitry. The analog receive circuitry may be configured to receive an analog signal from one or more (e.g., all) optical detectors of the optical sensor. In some embodiments, a microcontroller may also be provided with the optical sensor 200 and may perform any of various functions, including any one or more of controlling acquisition of optical signals by the plurality of optical detectors, performing demodulation of signals acquired from the plurality of optical detectors, and serving as a communication interface between the optical sensor 200 and a remote component, such as host module 106.
In some embodiments, both analog and digital circuitry may be included with the optical sensor 200. For example, as described above, the optical sources and/or optical detectors may be analog components and therefore it may be desirable in some embodiments to include analog drive and/or analog receive circuitry with the optical sensor 200. However, it may also be desirable to perform some digital functions, such as digital signal processing, on the optical sensor itself before sending any resulting signals off the optical sensor to a remote device. Thus, the optical sensor 200 may include, in some embodiments, an analog-to-digital converter (ADC), for example to convert analog signals received by the optical detectors 204 into digital signals. In some embodiments, the microcontroller includes the ADC.
In some embodiments, a field programmable gate array (FPGA) and/or application specific integrated circuit (ASIC) may be provided to perform one or more functions. For example, an FPGA may perform some digital functions, and in some embodiments a mixed signal FPGA may provide both digital and analog functions such as analog-to-digital conversion, digital-to-analog conversion, signal conditioning, and digital logic. In some embodiments, an ASIC may provide one or more analog and/or digital functions, such as any of those previously described.
As shown, the optical sensor 500 may include an LED 502 coupled to optics 504 (e.g., a lens) to produce an optical signal to irradiate a subject 506. Receiving optics (e.g., a lens) 508 provide the optical signal to a photodetector 510. Circuitry for controlling operation of the LED 502 includes an LED controller 512, as well as the microcontroller 514. The microcontroller 514 may send digital signals to the LED controller 512, which may in turn provide an analog control signal to the LED 502. Circuitry for processing the signals received by the photodetector 510 include a transimpedance amplifier (TIA) 516 (which converts a received current to a voltage and amplifies the voltage), an ADC 518, and the microcontroller 514.
The microcontroller 514 may perform various functions, such as any of those described elsewhere in the present application as being performed by a microcontroller, or any other suitable functions. According to an embodiment, the microcontroller 514 may execute firmware suitable to perform one or more of the following functions: awaiting a “start of frame” signal from a host; switching between optical sources of the optical sensor; enabling and controlling the optical sources including performing frequency modulation; providing a sampling clock to an ADC; controlling signal acquisition by the photodetector 510 and connected receive circuitry; demodulation of acquired signals (e.g., Fast Fourier Transform (FFT) or other suitable demodulation depending on the type of modulation used for optical signals produced by the LED 502); or communication handler between the optical sensor 500 and any remote components, such as host module 106 in
The host module 106 may be connected to the optical sensor (or multiple optical sensors) via a cabled or wireless connector 114. In some embodiments, the host module 106 may be connected to multiple optical sensors via a single cable which splits to go to each optical sensor. In some embodiments, the host module 106 may be connected to multiple optical sensors via respective cables.
This auxiliary input port may be used to capture digital information from an external device and synchronize in time (to the time resolution of a frame) the auxiliary data input with the data from the optical sensor 200. In some embodiments, the data provided on the auxiliary input port 606 may be provided with each frame of data from the optical sensor 200 to the central unit 108. As a non-limiting example, the timing and type of a stimulus given to a subject may be captured, for example in the context of a brain stimulus-response study.
In some embodiments, the host module 106 may also include an auxiliary output port 610, for example being configured to output data (e.g., 8 bits of data or any other suitable amount) to provide synchronization, frame count, Host status or configuration, or optical sensor status or configuration data to an external device. For example, such data may be provided in the context of synchronous monitoring.
In some embodiments, any auxiliary input and output ports of the host module 106 may be used for functional and performance testing and verification of the host module 106. Other uses for the auxiliary input and output ports are also possible.
The host module 106 may perform any suitable functions, such as any of those previously described in connection with host module 106. For example, the microcontroller 602 may execute firmware to perform one or more of the following functions: control of frame rate timing of the optical sensor; acting as a communication relay between the optical sensor and the central unit; consolidating or integrating data from multiple optical sensors into a single data packet; outputting auxiliary data to the auxiliary output port 610, or recording auxiliary input received over the auxiliary input port 606.
The central unit 108 may be a computer (e.g., a desktop computer, laptop computer, tablet computer, etc.) or other processing unit (e.g., a personal digital assistant (PDA), smartphone, etc.) and may be configured to perform one or more functions of the types previously described, for example by execution of suitable software and/or firmware. For example, the central unit 108 may perform post processing on signals detected by the photodetector 510 (e.g., performing unit conversion of the signals into optical power), though such functions may alternatively be performed by the host module 106 in some embodiments. The central unit may control and perform display of information, in image form, graphical form, textual form, or any other suitable form. In some embodiments, the central unit 108 may include a display 112 upon which information is displayed, for example to a clinician or other user. The displayed information may be representative of physical conditions (e.g., biological conditions) or characteristics of a subject detected by the optical sensor, such as hemoglobin levels (e.g., oxygenated hemoglobin, deoxygenated hemoglobin, total hemoglobin, or tissue oxygenation saturation). In some embodiments, the central unit may control analysis and/or display of images and/or information relating to two or more regions (or portions) of a subject's brain simultaneously (e.g., two hemispheres of the subject's brain). For example, referring to
As described previously, aspects of the application provide for continuous monitoring of physical characteristics and/or conditions of a subject. Thus, in those embodiments in which information is presented to a user (e.g., via a visual display), such display may be continuous, and may be updated continuously. Moreover, in some embodiments it may be desired to track, trend, and display changes of monitored conditions or characteristics of the subject, thus providing historical data for comparison. As an example, a user (e.g., a doctor) may analyze current data provided by an optical sensor as well as scrolling through previously collected data to do a comparison of how a property of interest (e.g., hemoglobin levels) has changed with time.
As described previously, the central unit 108 and host module 106 may be connected by a cabled or wireless connector 116. As a non-limiting example, the two may be connected by a TCP/IP (Ethernet) connection 608, though other connection types are also possible.
The optical sensor 500 may also comprise an LVDS driver 702 for an LVDS connection (e.g., connector 604) between the optical sensor 500 and the host module 106, which may couple to an LVDS module 705 in the host module 106. The host module 106 may also include a power supply connector 708 coupled to a power management block 704 in the optical sensor 500 to provide power to the optical sensor 500. The power management block 704 may include one or more power modules 710a-710c to provide a desired voltage level to one or more components of the optical sensor 500, as shown (e.g., the power modules may provide respective voltage levels). The optical sensor may also include an oscillator 712 to provide a reference clock signal to the microcontroller 514.
The configuration of
The ADCs 802a-802c may be arranged in a daisy chain configuration as previously described in connection with
In operation, all the optical detectors 204 may sample simultaneously. The sampling rate may be any suitable sampling rate, and in some embodiments may be between approximately 30-40 kHz, approximately 35 kHz, or any other suitable rate. In some embodiments, the wavelength of the optical sources may be isolated on the receiving side via frequency encoding techniques. For example, the optical signals from the optical sources may be frequency encoded (e.g., in the kHz range), and frequency decoding/demodulation may be performed on the receiving side.
In operation, the optical sources of an optical sensor may be cycled sequentially, a non-limiting example of such operation being illustrated in
During a time slot 906, the microcontroller may packetize and transfer data to the host module 106 representing the detected optical signals.
A buffer period 908 of relatively short duration (e.g., 1 millisecond) may then be observed to ensure no overlap in the data processing of the optical sources. Subsequently, the same sequence of events may be repeated for the second optical source (“optical source 2”), and so on for all the optical sources, as shown in
Alternative manners of operation are also possible. For example, in some embodiments parallel data processing may be performed, allowing for sampling of the optical sources to be performed nearly sequentially, i.e., with little or no time between the sampling of one optical source and another. In such embodiments, demodulation of received optical signals (e.g., time slot 904) and data transfer (e.g., time slot 906) may be performed substantially in parallel with the sampling operation.
A frame is completed after all the optical sources of the optical sensor have been activated. Any suitable frame rate may be used to provide a desired rate of data collection. As previously described, the host module may in turn provide the collected data to the central unit 108, which may optionally perform further processing and which may, in some embodiments, generate and display in image form, graphical form, and/or textual form data about one or more characteristics of the subject.
As should be appreciated from the foregoing description of
In some embodiments, an optical system may lack any fiber optics for communicating between an optical sensor of the system and a remote component (e.g., host module 106), even if one or more fiber optics may be used on the optical sensor itself to optically couple the optical sensor to the subject. Any such fiber optics on the optical sensor itself may be short, for example less than two inches in length, less than one inch in length, or any other suitable length. In such embodiments, it should be appreciated that an optical system may lack any fiber optics having a length greater than approximately two inches, which may provide one or more of the benefits described above with respect to systems lacking fiber optics between an optical sensor and a remote component.
Also, aspects of the present application provide optical systems and optical sensors which need no optical fibers to irradiate a subject with optical signals or detect optical signals from the subject. For instance, optical fibers are not needed to transmit an optical signal exiting a subject to a detector located remotely from the subject, and neither is any optical fiber needed to transmit to a subject an optical signal produced by an optical source located remotely from the subject. Rather, as described previously (e.g., in connection with FIGS. 2A and 3A-3C), an optical sensor, according to an aspect of the present application, may be configured to directly contact the subject, such that the optical sources and optical detectors may be in close proximity to the subject. Despite the system including, in some embodiments, a host module and/or central unit which may be located up to several feet or more away from the optical sensor, no optical fibers are needed. Thus, it should be appreciated that embodiments of the present application provide an optical system and/or optical sensor entirely lacking any fiber optics.
Referring again to
According to a non-limiting embodiment, the optical sensor 200 may have a length (e.g., in the y-direction in
The optical sources 202 and optical detectors 204 of the optical sensor 200 may be spaced by any suitable distances. For example, first nearest neighbor optical detectors (those optical detectors of an optical sensor array that are most closely spaced with respect to an optical source) may be within approximately 10-20 mm of the optical source (e.g., the distance L1 shown in
The optical sources 202 and optical detectors 204 may have any suitable dimensions. As mentioned, in at least some embodiments it may be desirable to have the optical sources and optical detectors close to the subject. Accordingly, in some embodiments the optical sources and/or optical detectors may be short, for example less than approximately 10 mm in height (in the z-direction of
In some embodiments, the optical sensor may be configured to directly contact the surface of a subject's brain, for example during brain surgery. The optical sensor may have any suitable configuration, including any suitable dimensions, for such functionality.
For instance, as previously described, in some embodiments it may be desirable for the optical sensor to be flexible, and thus the optical sources and optical detectors may be mechanically and/or electrically coupled via flexible internal structures.
The structure 1000 of
Although the configuration of
The circuitry modules 208a-208c may also be disposed on and interconnected by flexible circuitry board strips as shown, and may be coupled to the optical sources and/or optical detectors in this manner.
In some embodiments, such as that shown, the optical sources 202, optical detectors 204, and circuitry modules 208a-208c may each be disposed on a respective rigid circuit board 1006. The respective rigid circuit boards may provide support to the respective components (e.g., to the respective optical sources 202), but in some embodiments may be made no larger than necessary to provide such support and electrical connection to the components, to not negatively impact the flexibility of the structure 1000.
Electrical connection to the respective components (e.g., to the optical sources and optical detectors) may be provided via electrical traces on the flexible circuit board structure, which may make contact with electrical contacts on the respective rigid circuit boards.
The flexible circuit board strips 1002 and 1004 may have any suitable dimensions. Keeping in mind the dimensions previously described as applying to embodiments of the optical sensor 200, the flexible circuit board strips 1002 and 1004 may have lengths (in the x-direction in
In some embodiments, the interspersed pattern of flexible circuit board strips 1002 and 1004 shown in
As shown, the printed circuit board 1100 may include flexible circuit board strips 1002 and 1004 prior to release from the rest of the printed circuit board. A central circuit board segment 1102 interconnects the flexible circuit board strips 1002 and 1004. The central circuit board segment may have any suitable structure, and in the non-limiting example illustrated has a bifurcated structure. Other configurations are also possible.
Folding the printed circuit board 1100 along the line A-A in
It should be appreciated that the relative positioning of the flexible circuit board strips 1002 and 1004 illustrated in
The curved configuration of optical sensor 1200 may be beneficial in conforming to subjects with curved surfaces, such as a head. By providing for curvature in the support structure 1206, less force may be required to conform the optical sensor to the subject to achieve suitable optical coupling. The degree of curvature may be selected in dependence upon the anticipated curvature of subject surfaces to which the optical sensor 1200 is to be coupled. For example, if the optical sensor 1200 is to be placed against a subject's forehead, the degree of curvature may be selected accordingly. Non-limiting examples of suitable radii of curvature include between approximately 10 mm and 200 mm, between approximately 50 mm and 100 mm, any value within such ranges or any other suitable values. As a non-limiting example, the optical sensor 1200 may include curvature around both the x- and y-axes. For example, radius of curvature about the x-axis may be between approximately 100 mm and approximately 150 mm (e.g., 130 mm). The radius of curvature about the y-axis may be between approximately 25 mm and approximately 75 mm (e.g., 50 mm). Other configurations are also possible.
As described previously, an aspect of the present application provides hand-held devices for holding one or more optical sensors of the types described herein. Such hand-held devices may allow for flexibility in placement of an optical sensor and also provide an alternative to a more permanent support. Hand-held devices may be preferable, for example, when short duration optical monitoring is needed (e.g., as a spot check) since they may allow for easy placement of the optical sensor in contact with the subject and then easy removal.
The three segments 1302a-1302c may be provided to allow for bending or flexing of the optical sensor (not shown). For example, segment 1302a may be hingedly fixed to segment 1302b, and segment 1302b may be hingedly fixed to segment 1302c. In this manner, the three segments may be moved relative to each other, as will be further appreciated by reference to
The hand-held device may have any suitable dimensions. According to some embodiments, the segments 1302a-1302c may be sized to accommodate an optical sensor. For example the segments 1302a-1302 may have a combined length (in the x-direction in
The anchoring posts 1306 represent a non-limiting example of a mechanism for coupling to or otherwise engaging with an optical sensor. For example, the anchoring posts 1306 may alight with alignment holes, corners, notches, or other features of an optical sensor to hold the optical sensor in place. The anchoring posts may have any suitable dimensions for doing so. While four anchoring posts 1306 are shown, it should be appreciated that any suitable number may be provided for suitably engaging with an optical sensor.
Moreover, posts represent a non-limiting example of a mechanism for engaging an optical sensor. Other types of fasteners or couplers may alternatively or additionally be implemented, such as adhesives, straps, elastic bands, hook and loop fasteners, pins, ridges, walls, or other couplers.
The handle 1304 may have any suitable construction. In some embodiments, the handle 1304 may have an ergonomic contour. In some embodiments, the handle may be adjustable in length or angle.
In the embodiment shown, segments 1302a and 1302c may be moved by the same slider 1308, and thus may be moved in substantially the same manner as each other. However, not all embodiments are limited in this respect. For example, the hand-held device 1300 may be configured to allow for separate (i.e., independent) control of segments 1302a and 1302c.
Furthermore, it should be appreciated that a slider 1308 is a non-limiting example, and that any suitable adjustment mechanism may be used to provide control of the relative positioning of the segments 1302a-1302c. For example, buttons, knobs, or other control or adjustment mechanisms may be used.
The base 1402 may have a curvature to provide a desired curvature to an optical sensor held by the hand-held device 1400. The base may be made of plastic or any other suitable material.
The anchoring posts 1404 may engage the optical sensor, and may function in the manner described previously for anchoring posts 1306. The anchoring posts 1404 may be any of the types of fasteners or couplers described previously in connection with anchoring posts 1306.
The compression springs 1406 may apply pressure to the optical sensor to facilitate suitable coupling between the optical sensor and a subject. The springs may be configured to provide any desired degree of pressure. Also, springs represent a non-limiting example of a manner of applying pressure (e.g., local pressure) to the optical sensor and therefore to the subject. For example, air bladders or other compression chambers may additionally or alternatively be implemented.
The anchoring bolt 1408 may facilitate suitable engagement of the hand-held device with the optical sensor and may have any suitable construction for doing so.
The handle 1410 may allow the hand-held device 1400 to be held and manipulated by hand, and may have any suitable construction for doing so.
It should be appreciated that the examples of hand-held supports or devices shown in
According to an aspect of the application, an optical component having a columnar structure is provided.
As shown in the perspective view of
The columnar PCB 1502 may be formed of any suitable material and may have any suitable shape. In the non-limiting example illustrated, the columnar PCB 1502 has a substantially cylindrical shape with circular cross-section, though other shapes are also possible, such as square cross-sections, multi-sided cross sections, or any other suitable shape. The columnar PCB 1502 may be formed of any suitable material.
In some embodiments, the columnar PCB 1502 may include conductive traces on the upper surface 1504, a non-limiting example of which is shown and described below in connection with columnar PCB 1702 of
In some embodiments, the columnar PCB may be replaced by a spacer (e.g., lacking any conductive traces) having the same shape and dimensions as the columnar PCB 1502. In such cases, electrical connection from the support 1514 to an optically active element on the spacer may be made using wire leads passing through the spacer, or in any other suitable manner.
Furthermore, it should be appreciated that the columnar PCB 1502 may be any suitable type of PCB, including a fibre-glass sheet PCT (e.g., with copper sheets), a Molded Interconnect Device (MID), or other suitable structure functioning as a PCB. In some embodiments, the columnar PCB 1502 may be formed of a material that is thermally conductive and which may be used for heat dissipation. A ceramic PCB is a non-limiting example.
The optically transparent cover 1508 may serve to cover and protect an underlying optically active element, as will be further illustrated and described in connection with
For example, as shown, the optically transparent cover 1508 may have a substantially cylindrical cross-section (e.g., substantially matching that of the columnar PCB 1502) in some embodiments, and may have a rounded surface (e.g., a dome shape, a half-dome, etc.). However, other geometries are possible, including rectangular cross-sections, among others. Alternative configurations are possible, however, a non-limiting example of which is illustrated in
As shown in
Referring again to
The optically transparent cover may not be transparent to all wavelengths, in some embodiments. In some embodiments, the optically transparent cover may be transparent to optical wavelengths emitted by or detected by an optically active element which the optically transparent cover covers. Thus, in some embodiments the optically transparent cover may have any suitable optical response, including low pass, high pass, and band-pass optical responses. In some embodiments, the optically transparent cover may be transmissive rather than transparent.
The sleeve 1510 may be configured to at least partially surround the columnar PCB 1502 and the optically transparent cover 1508, and in some embodiments the sleeve 1510 is optional. When included, the sleeve 1510 may function as a support for maintaining the relative positioning of the columnar PCB 1502 and the optically transparent cover 1508. The sleeve 1510 may additionally or alternatively perform other functions. For example, the sleeve 1510 may be optically opaque in some embodiments, thus restricting an area or angle over which optical signals can enter/exit the optical component. In some embodiments, the inner wall of the sleeve 1510 may be reflective, for example being coated with a reflective coating. In some embodiments, the sleeve 1510 may be electrically conducting (e.g., formed at least partially of an electrically conductive material, such as having an electrically conductive coating), and may serve as an electrical contact, for example functioning as an electrical ground. Such a configuration is described further below, for example in connection with
The flange 1512 may have any suitable configuration for facilitating attachment of the optical component to the support 1514. An adhesive may be used to secure the columnar PCB 1502 to the flange 1512 and to secure the flange 1512 to the support 1514. However, other techniques for attaching the columnar PCB 1502, the flange 1512, and the support 1514 may be used, such as pins, screws, solder bonding, or any other suitable techniques.
The support 1514 may be a printed circuit board providing electrical connection to the optical component 1500, according to a non-limiting embodiment. Thus, support 1514 may include one or more electrical traces thereon in any suitable configuration for connecting to the optical component 1500. In a non-limiting example, the support 1514 may be a rigid printed circuit board.
The connector 1516 may have any suitable configuration for providing electrical interconnection between the optical component 1500 and the support 1514. The connector 1516 may include one or more pins 1518 (e.g., 2 pins, 4 pins, 6 pins, etc.). The pins 1518 may align with electrical contact pads, electrical traces, or other suitable conductive features on the support 1514 or optical component 1500. In some embodiments, the columnar PCB 1502 may include conductive traces on the bottom surface 1506 (not shown in
The optical component 1500 may have any suitable dimensions. According to an aspect of the present application, an optical component such as that of the type illustrated in
Some non-limiting examples of suitable dimensions for the optical component 1500 are now provided for purposes of illustration. It should be appreciated that other dimensions are possible, and that the dimensions may be selected based on an intended application of the optical component, for example based on expected obstacles the optical component 1500 may be configured to extend through.
The columnar PCB 1502 may have a height H1 (see
Because of the height H1, the upper surface 1504 and any optically active element disposed thereon may be higher than surrounding structures. For example, the upper surface 1504 is higher than the support 1514. Thus, if the optical component 1500 is positioned adjacent a subject (e.g., contacting the skin of a patient), any optically active element on the upper surface 1504 may be closer to the subject than if the optically active element was directly on, or otherwise closer to, the support 1514. In this manner, optical coupling of the optical component to a subject may be enhanced. Also, interference from surrounding structures may be minimized by elevating an optically active element on the supper surface 1504 above surrounding structures because of the height H1.
The optically transparent cover 1508 may have a width D1 substantially the same as that of the columnar PCB 1502, and thus having any of the dimensions described above in connection with columnar PCB 1502. The optically transparent cover 1508 may have two heights associated therewith, including a height H3 representing the height from the upper surface 1504 to the top of the sleeve 1510 and a total height H4. H3 may be between approximately 0.5 mm and approximately 3 mm, between approximately 1 mm and approximately 2 mm, approximately 1.5 mm, approximately 1.3 mm, or any other suitable value. H4 may be between approximately 1 mm and approximately 6 mm, between approximately 2 mm and approximately 4 mm, approximately 1 mm, approximately 1.5 mm, approximately 2.5 mm, less than approximately 3 mm, or any other suitable value.
The optical component 1500 may have a total height (e.g., H1+H4) of less than approximately 30 mm, less than approximately 10 mm, less than approximately 5 mm, less than approximately 3 mm, between approximately 5 mm and 15 mm, between approximately 2 mm and 6 mm, or any other suitable height.
In some embodiments, the optical component 1500 may be configured such that any optically active element disposed on the upper surface 1504 of the columnar PCB 1502 is located within 5 mm of the top of the optically transparent cover 1508, such that if the optically transparent cover 1508 is placed in contact with a surface of a subject, the optically active element is less than approximately 5 mm from the surface of the subject. In some embodiments, the optical component may be configured such that any optically active element is within approximately 3 mm of the surface of the subject, within approximately 2 mm, or within any other suitable distance.
The sleeve 1510 may have an inner diameter corresponding to the width D1 of the columnar PCB 1502. The sleeve 1510 may have an outer width D2 of between approximately 3 mm and approximately 7 mm, approximately 4 mm, approximately 5 mm, approximately 6 mm, or any other suitable value. In some embodiments, the sleeve 1510, which may represent an outer surface of the optical component 200 as shown in
It should be appreciated that the dimensions D1 and D2 are referred to herein generally as “widths,” but that they may take more specific forms depending on the shape of the corresponding optical structure. For example, D1 and/or D2 may represent diameters in embodiments in which the columnar PCB 1502, optically transparent cover 1508 and/or sleeve 1510 are cylindrical in nature. However, the columnar PCB 1502, optically transparent cover 1508 and/or sleeve 1510 are not limited to being cylindrical with a circular cross-section. Rather, they may have a square cross-section, a multi-sided cross-section, or any other suitable shapes. In some embodiments, the dimensions D1 and/or D2 may be properly referred to as lengths. Thus, the terminology “width” in this context represents a general identification of a dimension.
The optical component of
As shown, the optical source 1600 includes the columnar PCB 1502, the optically transparent cover 1508, and the sleeve 1510. Multiple optically active elements 1602 are disposed on the upper surface 1504 of the columnar PCB 1502. While four optically active elements 1602 are shown, any number (including one or more, e.g., two, three, eight, or some other number) may be included. In an embodiment, the optical source includes only four optically active elements 1602. The optically active elements 1602 may be emitters (also referred to herein by the terminology “optically emitting elements” and other similar terminology), such as light emitting diodes (LEDs), or any other suitable elements capable of producing optical signals to be emitted from the optical source 1600.
The optically active elements 1602 may electrically couple to the columnar PCB 1502 in any suitable manner. As previously described, the columnar PCB may have electrical contacts, electrical traces, or other suitable electrically conductive features on the upper surface 1504. The optically active elements 1602 may be electrically coupled to such conductive features, for example by solder bonding or in any other suitable manner. Thus, electrical signals (e.g., control signals) may be provided to the optically active elements 1602 via the columnar PCB 1502, for example to control activation of the optically active elements 1602.
As shown in
The optical source 1600 may optionally include a filter (not shown) disposed over one or more of the optically active elements 1602. The filter may be any suitable type of filter for passing desired wavelengths from the optically active elements 1602 and blocking other wavelengths. When included, the filter may have any suitable height, for example having any of the heights previously described in connection with H6. In some embodiments, the filter may be implemented as a coating on the optically active elements.
The optical source 1600 may be formed in any suitable manner. According to a non-limiting embodiment, the optically active elements 1602 may be fabricated separately from, and then disposed on, the columnar PCB 1502. The sleeve 1510 may then be positioned around the columnar PCB 1502. A liquid may then be filled into the sleeve 1510 and hardened to form the optically transparent cover 1508. In this way, the sleeve 1510 may function, at least partially, as a mold for formation of the optically transparent cover 208. In some such embodiments, the optically transparent cover 1508 may be formed of a resin (e.g., medical grade resin or other biocompatible resin or material). Alternatively, the optically transparent cover 1508 may be in a solid, preformed state, when disposed in the sleeve 1510. Alternatively, the optically transparent cover 1508 may be disposed on the upper surface 1504 of the columnar PCB 1502 prior to placement of the sleeve 1510 about the columnar PCB 1502. Other manners of making the optical source 1600 are also possible.
The dimensions of the optical source 1600 may take any suitable values, including any of those previously described for the corresponding components in connection with
As shown, the optical detector 1700 comprises a columnar PCB 1702, the sleeve 1510, a detecting element 1704, and the optically transparent cover 1508. A filter 1706 may also optionally be included, as shown.
The columnar PCB 1702 may be similar to previously described columnar PCB 1502, but is identified by a distinct reference numeral in
In a non-limiting embodiment, the sleeve 1510 may contact the conductive trace 1708 when the optical detector is assembled. The conductive trace 1708 may function as an electrical ground contact, and thus in a non-limiting embodiment the sleeve 1510 may be electrically grounded. The conductive trace pattern 1710 may be suitable for coupling to and communicating electrically with the detecting element 1704. For example, the detecting element may include a corresponding electrical trace pattern or pin configuration, as non-limiting examples, configured to align with the conductive trace pattern 1710. Other patterns than that represented by conductive trace pattern 1710 may alternatively be used, as the conductive trace pattern 1710 is a non-limiting example provided for purposes of illustration.
The columnar PCB 1702 may include conductive paths (e.g., conductive traces, conductive vias, etc.) between the conductive trace pattern 1710 and the bottom surface of the columnar PCB, thus allowing for transmission of electrical signals between the conductive trace pattern 1710 and components to which the columnar PCB 1702 may be connected, such as support 1514. Such conductive paths may pass through the columnar PCB 1702 (e.g., down the middle of the columnar PCB 1702) or extend along an outer surface of the columnar PCB 1702.
The detecting element 1704 may be any suitable type of detecting element for detecting desired optical signals (e.g., optical signals in a wavelength range of interest). In some embodiments, the detecting element 1704 may produce an electrical signal indicative of the intensity, phase, and/or frequency of detected optical signals. The detecting element 1704 may be a photodetector (e.g., a pin photodetector, a phototransistor, a silicon photodetector, or an infrared photodetector, as non-limiting examples). As shown in
As described, the optical detector 1700 may optionally comprise a filter 1706. The filter 1706 may filter out undesired wavelengths from any optical signals received by the optical detector 1700. According to a non-limiting embodiment, the filter 1706 may be a color filter, though other types of filters are also possible. The filter 1706 may be suitably positioned with respect to the detecting element 1704 to perform the filtering function. For example, the filter 1706 may be disposed on, and centered with respect to, the detecting element 1704 according to a non-limiting embodiment. In some embodiments, the filter 1706 may be implemented as a coating on the detecting element.
The optically transparent cover 1508, previously described, may be disposed on the columnar PCB 1702 and may cover the detecting element 1704 and filter 1706, as shown in
The optical detector 1700 may be formed in any suitable manner. According to a non-limiting embodiment, the detecting element 1704 may be fabricated separately from, and then disposed on, the columnar PCB 1702. Optionally, the filter 1706 may be disposed on the detecting element 1704. The sleeve 1510 may then be positioned around the columnar PCB 1702. A liquid may then be filled into the sleeve 1510 and hardened to form the optically transparent cover 1508. In this way, the sleeve 1510 may function, at least partially, as a mold for formation of the optically transparent cover 1508. In some such embodiments, the optically transparent cover 1508 may be formed of a resin (e.g., a medical grade resin or other biocompatible resin or material). Alternatively, the optically transparent cover 1508 may be in a solid, preformed state, when disposed in the sleeve 1510. Alternatively, the optically transparent cover 1508 may be disposed on the columnar PCB 1702 prior to placement of the sleeve 1510 about the columnar PCB 1702. Other manners of making the optical detector 1700 are also possible.
The optical detector 1700 may have any suitable dimensions. Referring to
Optical components according to aspects of the present application may be operated in any suitable manner, as the manner of operation is not limiting. For example, optical source 1600 and optical detector 1700 may be operated in any suitable manner to emit and detect, respectively, optical signals.
Optical components according to aspects of the present application may operate at any suitable wavelengths. Thus, optical sources (e.g., optical source 1600) may emit (via optically active element 1602) any suitable wavelengths of optical radiation. In some embodiments the optical sources may operate at any of the wavelengths described previously in connection with optical sources 202.
Optical detectors according to aspects of the present application, such as optical detector 1700, may detect the wavelengths emitted by the optical sources. Thus, for example, optical detector 1700 may detect any of the wavelengths previously described as being emitted by an optical source. In some embodiments, a filter of a detector (e.g., filter 1706) may select out certain wavelengths reaching a detecting element of an optical detector.
Optical components of the types described herein may be used in various contexts. For example, the optical components of the types described herein may be used in optical sensors 200 and in the system of
It should be appreciated from the foregoing that optical components according to various aspects of the present application may be used to emit and/or detect optical signals sent into and received from a subject's head. Detection of such optical signals may provide information relating to the subject, which may be useful, for example, in detecting and/or analyzing a physical condition of a subject (e.g., a patient's brain).
While system 100, and the sensor 104, represent a non-limiting example of systems and apparatus which may utilize optical components of the types described herein (e.g., optical component 1500, optical source 1600, optical detector 1700, etc.), it should be appreciated that optical components according to the various aspects of the present application are not limited to being used in such systems and apparatus. Thus, other uses for optical components according to aspects of the present application are also possible.
Applicants have appreciated that, in the context of performing diffuse optical tomography (DOT) measurements on a subject, it may be desirable to gather and/or analyze information about more than two physical characteristics or conditions of the subject. For example, when considering a human subject, it may be desirable to gather and/or analyze information relating to endogenous biological chromophores (e.g., oxygenated hemoglobin; de-oxygenated hemoglobin; lipids; water; myoglobin; bilirubin; and/or cytochrome C oxidase) and/or exogenous chromophores (e.g., indocyanine green (ICG) or other biologically compatible near infrared (NIR) absorbing optical dyes or tracers). Applicants have further appreciated that, in performing DOT investigations of a subject, the desire to gather information about more than two physical characteristics or conditions may be achieved by using more than two wavelengths, and furthermore that suitable positioning of optical sources and detectors allows for substantially the same spatial portion of a subject to be investigated using the different wavelengths.
Thus, according to an aspect of the application, a diffuse optical tomography (DOT) sensor includes a plurality of optical sources disposed at respective locations of the sensor. Each optical source of a first subset of the optical sources may be configured to produce or emit a first plurality of optical signals with a first plurality of center wavelengths and each optical source of a second subset of the optical sources may be configured to produce a second plurality of optical signals with a second plurality of center wavelengths. The first and second pluralities of center wavelengths may be different than each other, and thus the DOT sensor may produce optical signals of more wavelengths than are produced by any single optical source of the DOT sensor. In a non-limiting embodiment, each optical source of the first subset may produce optical signals of four center wavelengths and likewise each optical source of the second subset may produce optical signals of four center wavelengths different than the four center wavelengths produced by the optical sources of the first subset.
The DOT sensor may also include a plurality of optical detectors disposed at respective locations. The optical detectors may have suitable detection capabilities to be capable of detecting any of the wavelengths emitted by any of the optical sources. The optical detectors may be positioned relative to the first and second subsets of optical sources such that substantial spatial overlap occurs in the paths of the optical signals traversed from the first subset of optical sources to the optical detectors and the second subset of optical sources to the optical detectors. In this manner, substantially the same spatial area may be investigated using the first plurality of center wavelengths and the second plurality of center wavelengths. In a non-limiting embodiment, the optical sources and the optical detectors may collectively form an array.
In some embodiments, the subject may be a human patient and a target area of study may be the patient's brain, although other subjects and/or target areas of interest may be studied (e.g., a limb, a torso, skin flap, organ, breast, tissue exposed by surgery, or other region of interest). In such situations, it may be desirable to monitor multiple physical characteristics of the brain.
As described already, the use of multiple wavelengths when investigating a subject with an optical sensor (such as a DOT sensor) may facilitate investigation of multiple physical characteristics of a subject to which the DOT sensor is optically coupled. For example, the first or second pluralities of center wavelengths may be used to provide information about absorption or scattering within a subject. For example, the first or second pluralities of center wavelengths may be used to provide information about absorption of hemoglobin (oxygenated or deoxygenated) in the subject, absorption of lipids in the subject, absorption of water in the subject, or scattering behavior within the subject. For example, in some embodiments each wavelength of the first and second pluralities of center wavelengths may provide information about both absorption and scattering within the subject. In some embodiments, the first plurality of center wavelengths and/or the second plurality of center wavelengths may provide redundant information, i.e., information about the same physical characteristic (e.g., deoxygenated hemoglobin) of the subject as a different wavelength of the first or second pluralities of center wavelengths. Such redundancy may, for example, increase confidence in collected data related to a particular physical characteristic. Suitable processing of detected optical signals (e.g., provided by an optical detector of an optical sensor) may facilitate derivation of information relating to any of the above-listed items.
According to an aspect of the application, a method of operating an optical sensor such as sensor 200 is provided. The optical sensor may include a plurality of optical sources and a plurality of optical detectors. The optical sources may be controlled to irradiate a subject (e.g., a patient) with optical signals. According to an aspect, different optical sources of the optical sensor may emit different pluralities of center wavelengths, thus allowing for analysis of multiple different physical characteristics or conditions of the subject. The optical signals may pass through the subject and be detected by the optical detectors upon exit from the subject. In some embodiments, the optical signals from the sources may enter the subject and cause an optical emission within the subject that is then detected by the detectors.
For example, in some embodiments the optical sources of the optical sensor 200 need not all emit the same wavelengths. For example, a first optical source may emit a first wavelength (e.g., approximately 650 nm) and a second optical source may emit a second wavelength (e.g., approximately 800 nm). In fact, aspects of the application provide for different optical sources to emit different pluralities of wavelengths. Recognizing that in practice many optical emitters, such as LEDs, emit a spectrum of frequencies, be it narrowband or broadband, aspects of the application provide for different optical sources to emit different plurality of center wavelengths. By utilizing multiple optical sources to emit a greater number of wavelengths than would be possible or practical with a single optical source, information may be gathered relating to a greater number of physical characteristics of a subject than would be possible or practical with a single optical source. Also, the use of multiple wavelengths may facilitate detection of various quantities of interest with respect to the subject since different wavelengths of the radiation may behave differently when passing through the subject. A non-limiting example is now described in the context of
According to a non-limiting embodiment, optical source 1 in
In some embodiments, the different center wavelengths emitted by different optical sources may be “interleaved” with respect to each other. For example, a first optical source may emit wavelengths of 650 nm, 750 nm, 850 nm, and 925 nm, while a second optical source may emit wavelengths of 700 nm, 800 nm, 900 nm and 950 nm. Other manners of dividing the center wavelengths between two or more optical sources are also possible.
It can be seen from the above-described examples that optical source 1 may emit four different (center) wavelengths than optical source 2. The remaining optical sources of the optical sensor 200 may similarly be split between those that emit the first plurality of wavelengths and those that emit the second plurality of wavelengths. For example, optical sources 1, 4, 5, 8, and 9 may represent a first subset of optical sources in which each emits the first plurality of wavelengths, while optical sources 2, 3, 6, 7, and 10 may represent a second subset of optical sources in which each emits the second plurality of wavelengths. In this manner, the optical sensor 200 may operate with a greater number of wavelengths than produced by any single optical source of the optical sensor.
In those embodiments in which different optical sources of an optical sensor emit different pluralities of wavelengths, such as the non-limiting embodiment just described, the optical sources may be arranged in any suitable configuration in combination with the optical detectors such that the same spatial area of a subject may be investigated with the different wavelengths. Referring still to
While the above-described example identifies optical sources 1, 4, 5, 8, and 9 as emitting the same wavelengths as each other and optical sources 2, 3, 6, 7 and 10 as emitting the same wavelengths as each other, it should be appreciated that other configurations are possible. For example, optical sources 1, 3, 5, 7, and 9 may represent a first subset of optical sources in which each emits the first plurality of wavelengths and optical sources 2, 4, 6, 8, an 10 may represent a second subset of optical source in which each emits the second plurality of wavelengths. Other configurations are also possible.
Moreover, it should be appreciated that more than two subsets of optical sources may be provided in which the subsets emit different wavelengths than the other subsets. For example, three, four, and any number of subsets of optical sources emitting respective pluralities of wavelengths may be provided.
In the non-limiting example described above, optical source 1 and optical source 2 each emit four (center) wavelengths. It should be appreciated that any suitable number of two or more wavelengths (e.g., two, three, four, five, six, eight, ten, etc.) may be emitted, and that four represents a non-limiting example. For instance, optical source 1 may emit a first plurality of wavelengths comprising two or more first wavelengths and optical source 2 may emit a second plurality of wavelengths comprising two or more second wavelengths. Also, the optical sources need not emit the same number of wavelengths. For instance, optical source 1 may emit two center wavelengths and optical source 2 may emit three center wavelengths. Other numbers are also possible.
In some embodiments, a first optical source of an optical sensor emits a first plurality of center wavelengths consisting of two first center wavelengths and a second optical source of an optical sensor emits a second plurality of center wavelengths consisting of two second center wavelengths different than the two first center wavelengths. In some embodiments, a first optical source of an optical sensor emits a first plurality of center wavelengths consisting of four first center wavelengths and a second optical source of an optical sensor emits a second plurality of center wavelengths consisting of four second center wavelengths different than the four first center wavelengths. Other configurations are also possible.
For example, in some embodiments two optical sources may emit different pluralities of center wavelengths but may exhibit some overlap in the center wavelengths emitted. For example, two optical sources may each emit 750 nm and 800 nm, but one of the two optical sources may also emit 650 nm and 700 nm while the other optical source may also emit 850 nm and 900 nm. Other manners of partial overlap of the center wavelengths emitted by different optical sources are also possible.
It should also be appreciated that the center wavelengths listed above in the context of
The optical detectors may detect the wavelengths emitted by the optical sources. In some embodiments, all the optical detectors may be capable of detecting any of the wavelengths emitted by any of the optical sources. In such embodiments, all the optical detectors may be substantially identical to each other. However, in some embodiments different optical detectors may be capable of detecting different wavelength ranges from each other (e.g., due to different types of optical detecting elements or different filtering schemes, among other possibilities).
In addition to using different wavelengths, aspects of the present application provide for use of different optical intensities. For example, two optical sources emitting the same center wavelengths as each other may do so with different intensities. The different intensities may be used, for example, to improve signal-to-noise ratio (SNR) for the optical sources. In fact, in some scenarios it may be necessary to use different intensities for different wavelengths to improve SNR.
In some embodiments, the optical sensor 200 may be used to provide information about the concentration and oxygenation of hemoglobin in a subject (e.g., the concentration and oxygenation of hemoglobin in a subject's brain, muscle or other tissues). Thus, the wavelengths of radiation used by the optical sensor 200 may be selected to facilitate collection of such information. In some embodiments, the wavelengths utilized by the optical sensor 200 may be approximately equally dispersed over the range from approximately 650 nm to approximately 950 nm. A broader spectrum may be used at the higher end of this range, in some embodiments. A narrower range (i.e., narrower than 650 nm to 950 nm) may be used in some embodiments, for example those embodiments in which only two to four wavelengths are to be used. In some embodiments, only two wavelengths may be used, with one below the isosbestic point of hemoglobin, which is about 800 nm, and one above (e.g., one wavelength below approximately 765 nm and one wavelength above approximately 830 nm).
As previously described, a plurality of different wavelengths may be used by the optical sensor 200 to gather information relating to different characteristics of a subject (such as a human patient). In general, the use of N wavelengths may provide information about N targets (e.g., N chromophores). For example, the N targets may have respective absorption or scattering coefficients, and thus use of N different wavelengths may allow for solving for the N coefficients. In some embodiments, more than N wavelengths may be implemented by an optical system to determine the N coefficients, such that the solution for the N coefficients may be over-determined. Such a technique may be used to provide redundancy of information and/or a more robust solution.
As a non-limiting example, the use of two different wavelengths may provide information about absorption of oxygenated hemoglobin in the subject and absorption of deoxygenated hemoglobin in the subject. Use of an additional third wavelength may provide information about absorption of lipids in the subject, in addition to the information about absorption of oxygenated and deoxygenated hemoglobin. Use of an additional fourth wavelength may provide information about absorption of water in the subject in addition to the information about oxygenated and deoxygenated hemoglobin and lipids. Use of additional fifth and sixth wavelengths may provide information about scattering within the subject in addition to the types of information previously described. Thus, according to embodiments of the present application, first and second pluralities of wavelengths may in combination include N or more wavelengths to provide, in combination, information about absorption and/or scattering of N targets (e.g., any of those targets previously described). In some embodiments, four total wavelengths may be used, five total wavelengths, six total wavelengths, seven total wavelengths, eight total wavelengths, or any other suitable number.
Such wavelengths may be suitably selected based on the target (e.g., lipids, hemoglobin, etc.), and may be divided among optical sources of the optical sensor in any suitable manner. For example, a first optical source (e.g., optical source 1 in
In some embodiments, one or more wavelengths may be used by an optical sensor (e.g., optical sensor 200) to provide redundant information. For example, one or more wavelengths may provide redundant information to one or more other wavelengths used by the optical sensor. Such redundancy may be desirable to provide increased confidence in collected data with respect to a given target, to provide a backup data channel in the event a particular wavelength proves ineffective, or for any other reason.
Suitable processing of detected optical signals (e.g., provided by an optical detector of an optical sensor) may facilitate derivation of information relating to any of the above-listed items. Such processing may be performed, for example, by a host module 106 and/or central unit 108 of a system such as that of
An optical sensor having optical sources configured to emit different wavelengths or different pluralities of wavelengths may be operated in various manners including any of those described herein. For example, the operation described previously in connection with
As previously described, in some embodiments two or more (and in some cases, each) optical source of an optical sensor may emit a plurality of (center) wavelengths. Thus, considering the operation described in
As used herein, the emission of two signals is concurrent if the signals have any overlap in time as they are being emitted. Depending on the context, the emission of signals is substantially concurrent if overlapping in time by at least 80%, by at least 90%, or more. In some embodiments, signals may be emitted generally serially such that a first one or more signals is concurrent with a second one or more signals, the second one or more signals is concurrent with a third one or more signals, etc., even though the third one or more signals may or may not be concurrent with the first one or more signals. The emission of two signals is substantially simultaneous if overlapping in time by approximately 95% or more.
The operation previously described with respect to time slots 904, 906, and 908 may then be performed. Subsequently, the second optical source may be activated and the plurality of wavelengths from that optical source may be emitted sequentially, concurrently, substantially concurrently, or substantially simultaneously. Demodulation, packetization and transfer, and buffer time slots may then be observed, before proceeding to the third optical source. The process may continue until all the optical sources have been activated.
It should be appreciated that in an alternative embodiment demodulation of sampled signals from a first optical source, and packetization and transfer of data for the first optical source may occur in parallel to sampling of signals from a second optical source. Thus, the aspects described herein are not limited to a particular manner of timing sequence.
It should be appreciated from the foregoing that an aspect of the application provides a method of operating a diffuse optical tomography (DOT) sensor, comprising emitting, into a subject from a first optical source located at a first position of the DOT sensor, a first plurality of (center) wavelengths substantially concurrently during a first time interval and detecting the first plurality of wavelengths from the first optical source during the first time interval with first and second optical detectors located at second and third positions, respectively, of the DOT sensor. In some embodiments, the distance between the first position and the second position is less than a distance between the first position and the third position. For example, the first optical source and the first optical detector may be first nearest neighbors, and the first optical source and second optical detector may be second nearest neighbors.
The method may further include emitting, into the subject from a second optical source located at a fourth position of the DOT sensor, a second plurality of (center) wavelengths different than the first plurality of (center) wavelengths substantially concurrently during a second time interval. The first and second time intervals may be non-overlapping. The second plurality of (center) wavelengths from the second optical source may be detected with the first and second optical detectors of the DOT sensor.
The method may further include emitting, into the subject from a third optical source located at a fifth position of the DOT sensor, the first plurality of (center) wavelengths substantially concurrently during a third time interval. The third time interval may be non-overlapping with the first time interval and/or the second time interval. The first plurality of (center) wavelengths emitted from the third optical source may be detected during the third time interval with the first and second optical detectors.
In some embodiments, such as the non-limiting embodiment of
In some embodiments in which a method like that described above is implemented, only one optical source may be activated at any given time, and thus the wavelengths emitted by that optical source may be the only wavelengths emitted during that particular time interval. However, not all embodiments are limited in this respect. In some embodiments, for example, multiple optical sources may be activated at the same time.
Aspects of the present application relate to supports for supporting an optical sensor in a desired position with respect to a subject, for example, for use as support 102 in
In some embodiments, the supports may feature an open-top construction, allowing access to a desired part of a subject, such as the top of the subject's head, the area around a subject's ears, and/or the temporal region above a subject's cheekbone (the zygmotic arch). Thus, the multiple pieces of the support may be interconnected to form a loop around a chosen portion of the subject (e.g., the subject's head) without obstructing the portion desired to remain accessible (e.g., the top of the subject's head, the area around a subject's ears, and/or the temporal region above a subject's cheekbone). The supports may be removed by detaching (or disengaging/decoupling) the multiple pieces, without obstructing the portion of the subject desired to remain accessible. In this manner, the supports may be applied and removed without obstructing the portion of the subject desired to remain accessible, and therefore without obstructing any objects (e.g., medical instruments) in place on the portion of the subject desired to remain accessible.
In some embodiments, the supports may be disposable. The optical sensors may be used to analyze various subjects including medical patients. The supports may contact the subject (e.g., the medical patient), and therefore become soiled, contaminated, aesthetically unappealing, or otherwise impacted in a manner such that it may be desirable to dispose of and replace the support when using the optical sensor on a different subject, or even at various points in time during use of an optical sensor on the same subject. Thus, in some embodiments the supports may be disposable in nature, for example being formed of relatively inexpensive materials and being easily attached to or detached from one or more optical sensors. Thus, while a single optical sensor may be used in conjunction with multiple subjects, a support according to aspects of the present application may be disposed of after use on a single subject or multiple supports may be used on a single subject in turn and discarded.
The support may include multiple pieces of flexible and/or soft material which may be suitably attached to apply the optical sensor to the subject and which may be detached or disengaged from each other to remove the optical sensor from the subject. In some embodiments, the support may be configured to support an optical sensor against (or in contact with) a subject's head (e.g., in contact with a human patient's head). The support may include at least two distinct segments, which in some embodiments may be cushions and/or straps. A first segment (or cushion in some embodiments) may be configured to engage with (or couple to or contact) a back portion and, optionally, side portions of the subject's head. For example, the first segment may engage with a subject's occiput. A second segment (or cushion) may be configured to engage with (or couple to or contact) front and, optionally, side portions of the subject's head. For example, the first segment may be an elongated strip which wraps from one side of the subject's head around the front of the subject's head to the opposing side of the subject's head.
As shown in
As shown, the support 2000 has an open-top construction, such that the support 2000 engages with the head 2002 in a manner which leaves the top of the head 2002 unobstructed (or uncovered) by the support. Such a configuration may be desirable in circumstances in which access to the top of the head 2002 is desirable or necessary, for example when a doctor needs access to the top of the head 2002 to perform a procedure or evaluate the head 2002. Moreover, the support may allow unimpeded physical access to the area around the subject's ears, and/or the temporal region above the subject's cheekbone.
The first and/or second segments 2010 and 2012 may be formed of any suitable materials. In some embodiments, it may be desirable for the first and/or second segments 2010 and 2012 to be configured to flex or otherwise conform to the subject. For example, as shown, the first segment 2010 may conform to the back 2004 of the head 2002 and the second segment 2012 may be configured to conform to the front 2006 and sides 2008 of the head 2002. In some embodiments, the first and/or second segments 2010 and 2012 may be configured to flex in at least two orthogonal directions, such as the x and y-directions shown in
In some embodiments, the first and/or second segments 2010 and 2012 may be formed at least in part of materials suitable for use on a human subject and, in some instances, for use in a medical setting. For example, the first and/or second segments 2010 and 2012 may be formed of a soft material or cushioning material (e.g., foam (e.g., memory foam, laminated foam, polyurethane foam or other suitable foam), cloth, fabric, polyester, rubber, a combination of such materials, or any other suitable material) which may render the support 2000 more comfortable to the subject or wearer, as well as facilitating the ability of the support to conform to the subject, as described above. In some embodiments, the first and/or second segments 2010 and 2012 may be formed at least in part of a breathable material, wicking material, or other suitable material, for example to improve air flow and reduce moisture (e.g., sweat) retention. In some embodiments, the first segment and/or second segment 2010 and 2012 may be formed at least in part of a material exhibiting antimicrobial properties, stain removal properties, mildew resistance, or other properties, which may be important for example when the support is used on a subject with open wounds or other potentially harmful medical conditions. In some embodiments, the first segment and/or second segment may comprise medical grade fabric.
As shown in
The first segment 2010 and second segment 2012 may take any of various suitable configurations, which to at least some extent may depend on the manner in which the support is to be used. An example of a suitable first segment 2010 for engaging with a subject's head is shown in
As shown, the segment 2100 may include a body (or support or substrate) 2102, which may be a cushion in some embodiments. A strap 2104 is fastened (or affixed or anchored) to an upper part of the body 2102, on the outer surface as shown in
The body 2102 may be soft and/or conformable, for example to facilitate conforming of the segment 2100 to a subject. Thus, the body 2102 may be formed of any suitable material described herein for a support (e.g., foam (e.g., memory foam, laminated foam, polyurethane foam, or other suitable foam), cushioning, rubber, knit spacer material, fabric, polyester, any combination of those materials), or any other suitable material. Moreover, the lower portions 2108a and 2108b may be able to bend (or flex or fold) about the lines 2110a and 2110b, respectively, relative to the body 2102. For example, the lower portions 2108a and 2108b may be formed of distinct foam pads from the rest of body 2102, attached by stitching (e.g., the lines 2110a and 2110b may represent a physical structure forming a flex point such as stitching in some embodiments) or other delineating feature. Alternatively, the body 2102 may include a single structure (e.g., a single foam pad) with a suitable feature placed at the locations of lines 2110a and 2110b to make lower portions 2108a and 2108b distinctly flexible relative to the remainder of the body 2102.
The straps 2104, 2106a and 2106b may function to connect the segment 2100 to another segment of a support (e.g., second segment 2012 in
The segment 2100 may optionally include an indicator feature or alignment feature for providing an indication of the positioning of the segment. For example, an indicator 2114 may be provided as shown in
The segment 2200 may be formed of any suitable materials, including any of those previously described herein for supports or any other suitable materials. Thus, in some embodiments the segment 2200 may be configured to conform to a subject, may be soft, padded, cushioned, stretchable, flexible, or have any other suitable material construction.
In some embodiments, the segment 2200 may include a foam cushion having holes formed therein. The holes may allow the optical sources and/or detectors of an optical sensor to protrude from the foam cushion and contact a subject. However, the thickness of the foam cushion may be selected such that the optical sources and/or detectors protrude by a relatively small amount, such that the cushion may serve to cushion the optical sensor against the subject, thus providing increased comfort.
The segment 2200 may have any suitable dimensions for supporting an optical sensor and conforming with an intended subject. For example, in the context in which the segment 2200 is to be configured in the manner shown for second segment 2012 of
The segment 2200 may have various constructions.
As shown in
One or more of the first piece 2302, second piece 2304, and third piece 2306 may include a plurality of fasteners (or couplers) 2308 for engaging with or mechanically coupling to an optical sensor, in some embodiments the coupling being detachable. In the non-limiting example shown, each of the first piece 2302, second piece 2304, and third piece 2306 includes four fasteners (or couplers) 2308. The fasteners 2308 may be elastic bands, hook and loop components, adhesive pads, or any other suitable type of fastener. In some embodiments, a pouch, pocket, or open-faced frame may be used as the fastener with an optical sensor being inserted into the pouch/pocket/frame. In some embodiments, the fasteners 2308 may be configured to engage the corners of an optical sensor such as optical sensor 200. For example, an optical sensor may be rectangular and each of the fasteners 2308 of the second piece 2304 may engage a respective corner. In some embodiments, it may be desirable for the fasteners to be easily engaged with and disengaged from the optical sensor. In this manner, the segment 2300 (and support more generally) may be removed from an optical sensor and discarded. A new segment 2300 may then be used with the optical sensor.
In some embodiments, in addition to the fasteners 2308, at least part of the inner surface of the first piece 2302, second piece 2304, and/or third piece 2306 may be configured to restrict motion of an optical sensor when the optical sensor is in place. For example, the inner surface of the first piece 2302, second piece 2304, and/or third piece 2306 may be textured, may be rough, or may have other surface features which minimize or prevent movement/motion of the optical sensor against the surface.
As described, the second piece 2304 and third piece 2306 may be coupled to the first piece 2302 in a manner that allows them to slide relative to each other. For example, the second piece 2304 may be coupled to the first piece 2302 by a ring 2310a, which may represent or define a coupling point for coupling the first piece 2302 and second piece 2304. A non-limiting example of such a ring is illustrated in
The third piece 2306 may be attached to the first piece 2302 by a ring 2310b. The construction and operation of ring 2310b may be substantially the same as that of ring 2310a. Thus, the ring 2310b may define a coupling point of the third piece 2306 for coupling to the first piece 2302. The first piece 2302 and third piece 2306 may be separable from each other and separately replaced or discarded.
The first piece 2302 may also be coupled to the second piece 2304 and third piece 2306 at coupling points represented by the respective ends 2322 and 2324 of the second piece 2304 and third piece 2306, i.e., the second piece 2304 may be said to have a coupling point represented by end 2322 and the third piece 2306 may be said to have a coupling point represented by end 2324. The location of these coupling points relative to the first piece 2302 may be used to adjust the sizing of the support and the placement/positioning of optical sensors held by the second piece 2304 and third piece 2306 relative to the subject (e.g., the placement of optical sensors proximate the sides of the subject's head).
The coupling points represented by ends 2322 and 2324 may be coupled to the first piece 2302 by respective fasteners 2312, which may be adjustable in some embodiments. The fasteners 2312 may hold the first piece 2302, second piece 2304, and third piece 2306 in a relatively fixed position with respect to each other. However, the fasteners may be adjustable in that the placement at which second piece 2304 and third piece 2306 are coupled to the first piece 2302 may be adjusted. As an example, the fasteners 2312 may each have a width W2, and the ends 2322 and 2324 (representing coupling points) may be coupled to the first piece 2302 anywhere across the widths W2. In this manner, the location of coupling may be adjusted, and thus the size of the support may be adjusted as well as the positioning of the second and third pieces 2304 and 2306, and any optical sensors they may hold, relative to the subject when the support is in place.
The fasteners 2312 may be any suitable type of fasteners, and in some embodiments may be adjustable fasteners. In some embodiments, the fasteners may be hook and loop fasteners. For example, the fasteners 2312 may include hook portions and the second piece 2304 and third piece 2306 may be formed of a material (e.g., a fabric or other suitable material) which engages with the hook portions. In some embodiments, the second piece 2304 and third piece 2306 are detachable from the fasteners 2312, to provide the adjustable nature described above.
The pieces illustrated in
The second piece 2304 and third piece 2306 may further comprise respective openings (or holes) 2314. Such openings 2314 may allow for a strap or other connector from a different segment (e.g., from segment 2100) to engage the second piece 2304 and third piece 2306. For example, in a non-limiting embodiment, a first end of strap 2104 may pass through opening 2314 of second piece 2304 and the other end of strap 2104 may pass through opening 2314 of third piece 2306. The strap 2104 may then be folded such that the fasteners 2118a and 2118b connect back to the body 2102 of the segment 2100. An example of such a configuration is illustrated in connection with
Based on the foregoing, it should be appreciated that in some embodiments the segment 2100 and segment 2300 may be coupled together to form a loop or other closed contour. Specifically, in some non-limiting embodiments, the strap 2104 of segment 2100 may engaged the openings 2314 of second piece 2304 and third piece 2306 such that the segment 2100, second piece 2304, third piece 2306, and the portion of first piece 2302 between fasteners 2312 may form a loop. This loop may be fitted to a subject's head (or other region of interest). The size of the loop may be controlled, at least in part, by adjusting the strap 2104 and, in some embodiments, the straps 2106a and 2106b, which may be connected to the segment 2300.
It should be appreciated that merely engaging the strap 2104 with the second piece 2304 and third piece 2306 to form a loop does not necessarily tightly engage the ends 2303a and 2303b of the first piece 2302. Those ends 2303a and 2303b, which themselves may be considered straps anchored on the segment 2300 in some embodiments, may be used as tensioners or tighteners to adjust the tension (or fit or pressure or sizing) of the loop, as will be described further below. For example, pulling the ends 2303a and 2303b toward the front of the head may serve to tighten the support and increase the pressure of the optical sensors against the head (or subject more generally).
In some embodiments, the supports may include other features or mechanisms to control/adjust the pressure exerted by optical sensors against a subject. For example, compression elements (e.g., mechanical springs, inflatable chambers such as air bladders, or other compression elements) may be included as part of the supports. When included, such compression elements may provide an independent mechanism for adjusting the pressure of optical sensors against the subject.
As shown in
As shown, the ends 2303a and 2303b may include respective fasteners 2320a and 2320b. The fasteners 2320a-2320b may serve to fasten the respective ends 2303a and 2303b of first piece 2302 to a desired point for providing a desired fit or level of tension to the support. As a non-limiting example, the end 2303a may be folded back over the ring 2310a such that the fastener 2320a may be engaged with the portion 2318b. For example, the fastener 2320a may form a hook and loop closure with the portion 2318b. Similarly, the end 2303b may be folded back over the ring 2310b such that the fastener 2320a may be engaged with the portion 2318b, for example by forming a hook and loop closure or other suitable fastening closure.
The fasteners 2320a and 2320b may be any suitable fasteners, as the various aspects described herein are not limited in this respect. For example, the fasteners 2320a and 2320b may be hook and loop components, clips, buckles, adhesive pads, or other fasteners, and in some embodiments may form detachable closures.
The first piece 2302 may optionally include an indicator 2316, which may be any type of indicator as previously described in connection with indicator 2114 or any other suitable indicator or any other suitable indicator. The indicator 2316 may be used to aid user alignment of the segment 2300 with a desired feature of a subject. For example, the indicator may be aligned by the user with the a subject's forehead to ensure that optical sensors held by the support are properly positioned with respect to the subject. Depending on the nature of the indicator 2316, it may or may not be visible on the inner surface of the segment 2300 and thus is shown with dashed lining in
As should be appreciated from the foregoing, supports according to one or more aspects of the present application may include multiple segments (or pieces). The segments may be connected in various manners. For example, first piece 2302, second piece 2304, and third piece 2306 may, in some embodiments, be considered to part of a single segment. Alternatively, as previously described, the second piece 2304 and third piece 2306 may be separated from the first piece 2302 (e.g., by sliding the first piece 2302 out of rings 2310a and 2310b), but may be coupled to segment 2100 by straps 2104, 2106a and 2106b. Thus, the second piece 2304, third piece 2306, and segment 2100 may, in some embodiments, be considered to form a single segment for coupling to a rear portion and side portions of a subject's head. That segment may, in some embodiments, be configured to hold one or more optical sensors (e.g., one being held by each of second piece 2304 and third piece 2306).
Considering such a configuration, an aspect of the present application provides a support having a first (rear) segment configured to couple to a rear portion of a subject's head and having two forward coupling points (e.g., the ends 2322 and 2324) and two rear coupling points (e.g., defined by rings 2310a and 2310b). The support may further include a second (front) segment having a center portion configured to adjustably couple to the forward coupling points of the first segment and having two ends configured to slidably (or otherwise variably) couple to the two rear coupling point of the first segment. The ends of the second segment may function as tensioners to adjust a tension of the support by actuating the slidable coupling to the first segment (e.g., by pulling the ends of the second segment forward away from the first segment).
In some embodiments, the second piece 2304 and third piece 2306 may be considered o each have multiple (e.g., two) coupling points. For example, the second piece 2304 may have coupling points defined by end 2322 and ring 2310a. The third piece 506 may have coupling points defined by end 2324 and ring 2310b. One coupling point for each may be used to adjust a sizing of the support and/or a positioning of an optical sensor relative to a subject. Another coupling point of each piece 2304 and 2306 may be used to adjust a tension of the support (e.g., by accommodating a tensioner).
According to an aspect of the present application, a support may comprise two straps. A first strap may be considered to engage with a rear portion and, optionally, sides of a subject's head. A second strap may be configured to engage with a front portion and, optionally, sides of the subject's head. The first and second straps may be couplable to each other via one or more first adjustable coupling points. One or more additional coupling points may serve as points via which to apply tension to the support. In some embodiments, the first adjustable coupling points may be configured to be positioned between optical sensors held by the support. For example, end 2322 when fastened is located between the optical sensors held by first piece 2302 and second piece 2304 and the end 2324 when fastened is located between the optical sensors held by first piece 2302 and third piece 2306. The additional coupling points may be located substantially on opposite ends of the optical sensors. For example, the rings 2310a and 2310b may be positioned substantially opposite the ends 2322 and 2324 and thus on opposite ends of the optical sensors held by the second piece 2304 and third piece 2306.
In some embodiments, a support comprising four pieces is provided. The support may include front, rear, and two side pieces. The side pieces may be coupled to the front and rear pieces in any suitable manner to form a substantially closed contour. Any one or more of the pieces may be configured to hold an optical sensor.
It should be appreciated that various manners of applying supports of the types described herein to a subject are possible, some of which have been previously described. As a non-limiting example, a manner of applying a support comprising segments 2100 and 2300 is now described. The method may begin by engaging at least one fastener or connector to form a loop at least partially defined by the segment 2100 and segment 2300. For example, strap 2104 of segment 2100 may be fed through the openings 2314 of second piece 2304 and third piece 2306 and the fasteners 2118a and 2118b fastened to the segment 2100.
The loop formed by segments 2100 and 2300 may then be placed about the subject's head such that the loop wraps substantially around a circumference of the subject's head. At least one tensioner may then be actuated to adjust the tension of the loop around the subject's head. For example, ends 2303a and 2303b, which may be positioned proximate opposed sides of the subject's head, may be pulled toward the front of the subject's head and fasteners 2320a and 2320b fastened to an outer surface of first piece 2302. Thus, a desired tension of the support around the subject's head may be achieved.
Next, straps 2106a and 2106b of segment 2100 may be fastened to an outer surface of segment 2300. For example, straps 2106a and 2106b may be fastened to the ends 2303a and 2303b. In this manner, lower portions 2108a and 2108b may be made to lie flush with the subject's head and provide additional tension/fit control.
In some embodiments, the support may be placed about the subject's head prior to forming a completed loop. For example, second piece 2304 and third piece 2306 may be coupled to the segment 2100 using the strap 2104. The second piece 2304 (or third piece 2306) may be coupled to the first piece 2302, for example with the fastener 2312. The support may then be placed about the subject's head and a completed loop then formed by coupling the remaining one of second piece 2304 and third piece 2306 to the first piece 2302 with the fastener 2312. The support may then be tightened. For example, one or both of the ends 2303a and 2303b may be free at this stage, and may be fitted through respective rings 2310a and 2310b, pulled tight, and, using fasteners 2320a and 2320b, fastened to an outer surface of first piece 2302. According to this approach, the support may be positioned about the subject's head without disturbing objects (e.g., drains) on the subject's head.
It should be appreciated from the foregoing that in some embodiments supports may include distinct mechanisms for forming a support loop and for tightening the loop. For example, a loop may be formed as described with strap 2104, which in forming the loop may provide some control over size/tension of the support. However, ends 2303a and 2303b (or other suitable tensioners) may act independently to adjust the sizing/tension of the loop once formed.
As previously described, in some scenarios it may be desirable to replace a support of the types described herein while reusing the optical sensor(s) supported by the support. Thus, the process described above for engaging the support may be repeated. For example, after the support has been fitted to the subject and when it is desired to replace the support, the support may be removed by decoupling segments 2100 and 2300. The optical sensor(s) may be removed from the segment 2300 and segment 2100 and/or 2300 may be discarded. New segments 2100 and 2300 may be obtained, and the optical sensor(s) coupled to the segment 2300. The segments 2100 and 2300 may then be coupled together and fitted to the subject (the original subject or a new subject) in the manner previously described. In this manner, the support may be replaced.
Although various examples of supports have been described herein, it should be appreciated that alternatives falling within one or more aspects of the present application are possible. For example, one or more additional straps may be added to the supports described herein. As a non-limiting example, a chin strap may be included with the supports described herein, for example to prevent unwanted movement of the support toward the top of the subject's head. Alternatively or additionally, an overhead strap may be included with the supports described herein, configured to pass over a top portion of the subject's head. Such a strap may prevent unwanted downward movement of the support. Such a strap may also be used to apply additional pressure inward on the support (i.e., toward the subject's head).
Moreover, it should be appreciated that supports of the types described herein may, in some embodiments, be substantially reversed. For example, rather than a configuration in which a support segment is provided to couple to the front of a subject's head and for which tension is applied by pulling straps toward the front of the subject's head, the tensioning may be configured to be pulled toward the rear of the subject's head (e.g., the sizing and tensioning functions may be substantially reversed compared to the orientations described in some of the preceding examples). Other configurations are also possible.
Various benefits may be provided by one or more aspects of the present application. Following is a description of some benefits which may be achieved from implementing one or more aspects. However, it should be appreciated that not all aspects necessarily provide all listed benefits, and that benefits other than those listed may be provided. Thus, the benefits described herein are non-limiting examples.
Aspects of the present application provide for easily applied and removed supports for optical sensors. The supports may be formed of materials that are comfortable to the wearer, safe in a medical environment, and relatively inexpensive. The supports may easily engage with and disengage from an optical sensor, such that the supports may be disposable. The supports may provide multiple mechanisms for adjusting the sizing/fit of the support and the pressure of the optical sensor against the subject. Thus, accurate and comfortable fit may be achieved.
Aspects of the present application relate to liners for optical tomography sensors and related apparatus and methods. As previously described, an optical sensor (e.g., sensor 200) may be positioned to contact a subject. Such positioning may be beneficial and/or necessary in some embodiments to ensure accurate operation of the sensor. However, direct contact between the optical components (e.g., optical sources and optical detectors) and the subject may be undesirable for various reasons, and thus aspects of the present application provide for a liner to be placed on the optical sensor.
Direct contact between an optical sensor and a subject (e.g., a patient) may be harmful to the subject and/or the sensor. For example, if the optical sensor is to be used on multiple subjects, then direct contact of the optical sensor with multiple subjects may represent a bio-contamination hazard, a re- or cross-infection hazard, and more generally compromise hygienic safety. Cleaning the optical sensor itself may be difficult if it was to become soiled. If direct contact is made between the optical sensor and the subject, the optical sensor itself may be damaged, for example by getting scratched or otherwise modified in a manner that could be detrimental to the sensor operation.
Accordingly, aspects of the present application provide liners for use with optical sensors of the types that may be used in optical tomography systems, such as sensor 200 and the system of
According to an aspect of the present application, a liner for an optical sensor of the type that may be used in an optical tomography system (e.g., system 100 of
A liner according to an aspect of the present application may be implemented with various types of optical sensors having various configurations, a non-limiting example of which is the optical sensor 200. Suitable liners for use with such an optical sensor are shown and described in connection with
The liner 3000 may be configured to align with and engage with (or couple to, mate to, or other similar terminology) the optical sensor 200 of
The liner 3000 may optionally include a tab 3006 or other suitable feature for facilitating removal of the liner 3000 from an optical sensor. For example, when it is desired to remove the liner 3000 from an optical sensor (e.g., when switching between a first subject and a second subject), a user may grasp the tab 3006 and pull the liner 3000 off the optical sensor 200. While the liner 3000 is illustrated as including a tab 3006, it should be appreciated that other structures (e.g., other than a tab) may alternatively or additionally be provided to facilitate removal, and more generally handling, of the liner 3000.
The liner 3000 may have any suitable dimensions. In some embodiments, the liner 3000 may have a length L5 in the y-direction in
The liner 3000 may have a thickness T1 that is relatively small compared to L5 and W3 in some embodiments. The thickness T1 may be the thickness of substantially all of the liner 3000, including the indentations 3004 as well as the portions of the flexible sheet 3002 between the indentations 3004 though not all embodiments are limited in this respect. In some embodiments, the thickness T1 may be uniform for the entire flexible sheet, whereas in other embodiments the flexible sheet may have a varying thickness, and T1 may represent the maximum thickness or an average thickness. The thickness T1 (whether a maximum, average, or uniform value) may be, for example, less than approximately 20 mm, less than approximately 10 mm, less than approximately 5 mm, less than approximately 3 mm, less than approximately 2 mm, between approximately 0.5 mm and approximately 2 mm, or any other suitable value. As previously described, the liner may be flexible in some embodiments, and choosing a small thickness T1 may facilitate flexing of the liner. Moreover, since the liner 3000 may overlie the optical sources 202 and optical detectors 204 it may be desirable for the liner 3000 to have a small thickness to facilitate positioning of the optical sources 202 and/or optical detectors 204 close to a subject (e.g., a patient's head).
In some embodiments, the liner may be substantially as large as or larger than an optical sensor. For example, the liner may cover not only the optical sources and optical detectors of an optical sensor, but any electronics (e.g., circuitry modules 208a-208c). In some embodiments, the liner may substantially encase the optical sensor though allowing for a cable or other connector between the optical sensor and external components. For example, in some embodiments the liner may be a pouch or bag into which the optical sensor may be placed.
The indentations 3004 may be sized to accommodate the optical sources 202 and optical detectors 204 therein. For example, the indentations 3004 may have a width (e.g., a diameter or other width) and height, illustrated and described below in connection with
As described, in some embodiments a liner may be sized and applied to an optical sensor to prevent an air gap between the optical components (e.g., optical sources/detectors) and the liner. In addition to suitable sizing of the liner, the liner may include small openings/holes suitable positioned (e.g., on a tip of the indentations 3004) to allow air to escape. Alternatively, a channel (or more than one channel) may be formed on an inner surface of the liner to allow air to move from over the optical source/detector toward a base part of the liner.
In an alternative embodiment, the indentations 3004 may be replaced by sections of stretchable material (e.g., polyurethane). For example, the liner may be formed of two materials, one being relatively non-stretchable and a plurality of stretchable portions arranged in substantially the manner of indentations 3004. The liner may then be placed over an optical sensor and the stretchable portions (e.g., formed of a stretchable film) may stretch to conform to the optical sources and optical detectors of the optical sensor, thus assuming a shape much like that of the indentations 3004. In some such embodiments, the stretchable portions may be optically clear (as described further below) and the remainder of the liner may be optically opaque.
The liner 3000 may be formed of any suitable material, which in some embodiments may be a biocompatible material. In some embodiments, the material may be non-allergenic. As previously described, the liner 3000 may be flexible in some embodiments, and thus may be formed of a flexible material, such as a rubber. The liner may be soft or pliable, and thus in some embodiments may operate as a soft cover for an optical sensor. The material may provide desired optical properties for the liner 3000. For example, the indentations 3004 or a portion thereof (e.g., the tips of the indentations) may be formed of a material that is optically transparent to the wavelengths implemented by the optical source 202 and optical detectors 204. The remainder of the flexible sheet 3002 may be formed of a material that is optically opaque to the wavelengths implemented by the optical sources 202 and optical detectors 204, i.e., the portion of the liner between the indentations may be optically opaque. In this manner, undesirable tunneling or channeling of optical signals from an optical source through the support structure 206 to an optical detector of the optical sensor 200 may be avoided. Thus, according to a non-limiting embodiment, the indentations 3004 may be formed of optically clear material such as NuSil-6033, and the remainder of flexible sheet 3002 may be formed of opaque material such as NuSil MED-6033, with Silcopas 220 black.
The liner 3000 may be formed of a material providing desired mechanical properties. For example, as previously described, the liner 3000 may be intended to be applied to and removed from an optical sensor (e.g., optical sensor 200) and thus it may be desired for the liner 3000 to be formed of a material that is capable of stretching and resisting tearing. In some embodiments, the flexible sheet 3002 may be formed of a material having an elongation of at least 150%, between approximately 100% and approximately 900%, any value in between, or any other suitable value. In some embodiments, the material may have a tear strength of approximately 80 pounds per inch (ppi), between approximately 30 ppi and approximately 100 ppi, any value in between, or any other suitable value. In some embodiments, the material may have a durometer of 50A, between 10A and 70A, any value in between, or any other suitable value. In some embodiments, the liner may be formed of a material which is capable of being cleaned (e.g., by wiping).
The first portion 3008 may be, in some embodiments, considered the base or bottom portion of a columnar structure of the indentation, and the second portion may be considered the top portion or cover portion of the indentation. The second portion 3010 may also be referred to as a tip (e.g., an optical tip, optically transparent tip, or other similar terminology). As a non-limiting example, the second portions 3010 may be formed of NuSil MED-6033 or thin polyurethane, which may be optically clear. The first portions 3008 may be formed of NuSil MED-6033, with Silcopas 220 black, or a black polyurethane sheet. In some embodiments, the second portion 3010 may not be included with the liner, i.e., the indentations 3004 may be holes where the second portion 3010 is replaced by an opening in the liner.
The first portion 3008 and second portion 3010 may have any suitable dimensions. In some embodiments, the first portion 3008 may have a height H9 and the second portion 3010 may have a height H10. The height H10 may be selected to be just large enough to provide a desired emission/reception angle for an optical source/optical detector, respectively, to be fitted inside the indentation 3004, in some embodiments. In some embodiments, the height of H10 may be between approximately 1 mm and approximately 6 mm, between approximately 2 mm and approximately 4 mm, approximately 1 mm, approximately 1.5 mm, approximately 2.5 mm, less than 5 mm, less than approximately 3 mm, less than 2 mm, any value between 1 mm and 5 mm, or any other suitable value. The height H9 may then represent the remaining height of the indentation 3004, and may assume any suitable values, such between approximately 2 mm and 20 mm, between approximately 2 mm and 10 mm, between approximately 3 mm and 7 mm (e.g., 4 mm, 5 mm, or 6 mm), any value within such ranges, or any other suitable height.
The indentations 3004 may have a width D4 (e.g., a diameter or other width) of any suitable value. The width may represent the inner width of the indentation or an outer width. The walls of the indentations may be thin (e.g., having any of the thicknesses previously described in connection with T1 or any other suitable thickness, though in some embodiments it may be desirable for the walls of the indentations to be thinner than T1, such as on the order of 1 mm). As non-limiting example, D4 may be between approximately 3 mm and approximately 10 mm, between approximately 4 mm and approximately 7 mm, approximately 4.5 mm, approximately 5 mm, any value in those ranges, or any other suitable width.
As a non-limiting example, the liner 3000 illustrated in
As previously described in connection with
Liners of the types described herein may be fabricated in any suitable manner. According to a non-limiting embodiment, a liner may be molded. In some embodiments, a multiple step (e.g., two-step) molding processing may be used. For example, considering the liner 3000 illustrated in
As can also be seen from the inset of
As previously described, liners of the types described herein (e.g., liners 3000 and 3020 of
It may be desirable to make application and removal of a liner from an optical sensor a relatively easy process, so that users can perform the operation without requiring significant time and without risking damage to the liner or the optical sensor. According to an aspect of the present application, an applicator device may be provided to facilitate applying a liner to an optical sensor. The applicator device may be handheld in some embodiments. A non-limiting example is illustrated in
The upper surface 3204 may be formed to engage suitably with a flexible sheet (e.g., flexible sheet 3002) of a liner such that when the device 3200 is pressed onto an optical sensor the upper surface 3202 may force the liner onto the optical sensor. A non-limiting example of such operation will be described further below in connection with
The device 3200 may be formed of any suitable material. In some embodiments, the device 3200 may be rigid (or substantially rigid) such that it may withstand pressure and be used to force a liner into place on an optical sensor when pushed. Thus, plastic, metal, or other suitable rigid material may be used to form the device 3200.
The device 3200 may have any suitable dimensions. For example, the support structure may have a length L7, a width W5, and a thickness T3. The length L7 may be substantially the same as the length of a liner to be applied with the device 3200, and thus may have any of the values previously described for the length of liners or any other suitable value, such as being less than approximately six inches, less than approximately 5 inches, or any other suitable value. The width W5 may be substantially the same as the width of a liner to be applied with the device 3200, and thus may have any of the values previously described for the width of liners or any other suitable value, such as less than approximately four inches, less than approximately three inches, or any other suitable value. The thickness T3 may be suitable to provide the device 3200 with sufficient rigidity and may, in some embodiments, be at least as large as or greater than the height of the indentions/protrusions of a liner to be applied by device 3200, such that the openings 3204 may have sufficient dimensions to accommodate the indentations/protrusions of the liner. As non-limiting examples, the thickness T3 may be between approximately ¼ inch and 2 inches.
The openings 3204 may have a width D5 (e.g., a diameter or other width) of any suitable value to accommodate the indentations of a liner to be applied by the device 3200. In some embodiments, the width D5 may be sufficiently larger than the width of the indentations of a liner such that indentations may fit loosely within the openings 3204, i.e., the openings 3204 of the device 3200 may be wider than the indentations of a liner. In this manner, after the liner is applied to the optical sensor 200, an example of which is shown in connection with
The openings 3204 may have any suitable depth to accommodate the indentations of a liner. As can be seen from
As shown in
A force may be applied to the applicator device 3400 to ensure a good fit between the liner 3000 and the optical sensor. For example, a force may be applied to engage the liner 3000 and optical sensor 200 such that no gap exists between the two, including no air gap. As previously described, for example in connection with
As shown in
As previously described, a liner (e.g., liner 3000 or 3020) may be removable (or detachable, or decouplable) from an optical sensor. Removal may be performed in any suitable manner. For example, referring to
While
According to an aspect of the present application, a structure may be provided for controlling how an optical sensor makes contact with a subject. For example, considering the optical sensor 200, it can be seen that the optical sources 202 and optical detectors 204 may protrude above the support structure 206 and thus may act as points which contact the subject. Depending on the nature of the subject, the material used to form the optical sources 202 and optical detectors 204, and the pressure applied in coupling the optical sensor to the subject, such contact may be uncomfortable or damaging in some scenarios. For example, applying the optical sensor 200 to a subject's head may result in discomfort and/or leave a pattern of indentations in the subject's head from the optical sources 202 and optical detectors 204. According to an aspect of the present application, a structure may be provided to minimize discomfort.
The structure 3500 may be formed of any suitable material. In some embodiments, the substrate 3502 may be formed of a soft or cushioning material and/or a compressible material, such as foam, rubber, or other soft material. In some embodiments, the structure 3502 may be formed of multiple layers. For example, a first layer may be formed of rubber and a second layer may be formed of foam. The first layer may be configured to contact an optical sensor and thus may be formed of a material that will resist moving relative to the optical sensor when the structure 3500 is mechanically engaged with (or coupled with) the optical sensor. The substrate 3502 may be formed of a material that is optically opaque in some embodiments, for example to prevent cross-talk between optical sources and optical detectors of the optical sensor.
The structure 3500 may have any suitable dimensions, including a length L8, a width W6, and a thickness T4. The length L8 may be substantially the same as the length of the optical sensor (or liner) to which the structure 3500 is to be applied, and thus may have any of the values previously described for example in connection with L5, or any other suitable. The width W6 may be substantially the same as the width of an optical sensor (or a liner) to which the structure 3500 is to be applied, and thus may have any of the values previously described, for example, in connection with W3. The thickness T4 may be selected to provide a desired relative positioning of the upper surface of the substrate 3502 and the tips of the optical sources 202 and optical detectors 204. For example, the thickness T4 may be between approximately 2 mm and 25 mm, between approximately 2 mm and 15 mm, between approximately 3 mm and 10 mm (e.g., 4 mm, 5 mm, or 6 mm), any value within such ranges, or any other suitable value.
The holes 3504 may have any suitable widths D6, which in some embodiments may be a diameter. As previously described, the holes may be sized suitably to allow the optical sources and/or optical detectors of an optical sensor to project through. Thus, the width D6 may be larger than the width of an optical source or optical detector. In some embodiments, the structure 3500 may be intended to fit over an optical sensor when a liner (e.g., liner 3000) is in place, and thus the holes 3504 may have widths D6 sufficiently large to accommodate the optical sources 202 and optical detectors 204 with the additional thickness of the liner. As non-limiting examples, the width D6 may be between approximately 3 mm and approximately 10 mm, between approximately 4 mm and approximately 7 mm, any value in those ranges, approximately 4 mm, approximately 5 mm, or any other suitable width.
It should be appreciated that the holes 3504 may have any suitable shape to accommodate optical sources and optical detectors. The circular shape illustrated is a non-limiting example. Alternative examples include rectangular holes, square holes, triangular holes, or any other suitable shape(s).
In some embodiments, a structure such as structure 3500 may be configured to overlie a liner of the types described herein. For example, a liner (e.g., liner 3000 or 3020) may be applied to an optical sensor, and a structure (e.g., structure 3500) acting as a cushion may be placed over the liner. However, not all embodiments are limited in this manner.
In some embodiments, a structure such as structure 3500 may be considered a spacer, pad, cushion, or may be referred to by other similar terminology.
Various benefits may be provided by one or more aspects of the present application. Following is a description of some benefits which may be achieved from implementing one or more aspects. However, it should be appreciated that not all aspects necessarily provide all listed benefits, and that benefits other than those listed may be provided. Thus, the benefits described herein are non-limiting examples.
Aspects of the present application provide for easily applied and removed liners for optical sensors. The liners may minimize or eliminate bio-contamination and may protect the optical sensor itself. The liners may be relatively inexpensive and disposable and may minimize or obviate the need (and therefore the associated cost and effort) of cleaning an optical sensor. The liners may also increase the comfort of subjects (e.g., patients) to which the optical sensors may be coupled, for example by providing a relatively soft surface to make contact with the subject. In some embodiments, the liners may function as a thermal (e.g., heat) barrier between a subject and an optical sensor. For example, the liners may be formed of a thermally insulating material.
Optical tomography sensors and related apparatus and methods have been described. The present application covers the combination of all that is described herein. For example, the aspects described herein may be used individually, all together, or in any combination of two or more, as the present application is not limited in this respect.
Some non-limiting examples of the manner in which the aspects described herein may be combined are now described, though it should be appreciated that other aspects and embodiments may also be combined. As a first non-limiting example, the optical sensors (e.g., optical sensor 200 of
Moreover, the optical components described herein may be operated such that different optical components emit different pluralities of center wavelengths, as described herein. For example, a first optical component of the type illustrated in
Thus, as a non-limiting example, an optical sensor of the types described herein may utilize optical sources and detectors of the types described herein, which may be operated in accordance with one or more aspects in which different optical sources emit different pluralities of center wavelengths).
As another example, it has been described that drive circuitry of an optical sensor may control operation of one or more optical sources of an optical sensor. For example, as described previously, drive circuitry may control the ON/OFF state of the optical sources (and therefore the duration of the optical signals emitted by the optical sources), the frequency modulation of the optical sources and/or the emission intensity and power of the optical sources (e.g., by controlling the current to the optical sources) of an optical sensor. Such control may be wavelength specific, meaning that the drive circuitry may control the described features (e.g., ON/OFF state, frequency modulation and/or emission intensity and power) of different wavelengths differently. Thus, for example, optical sensors of the type described herein may be operated such that different wavelengths of a first and/or second plurality of wavelengths as described herein may be independently controlled with the previously described drive circuitry.
As another non-limiting example, the supports described herein may be used to hold optical sensors of the types described herein. For instance, one optical sensor 200 may be held by each of the first piece 2302, second piece 2304, and third piece 2306 of the support of
Moreover, the liners described herein may be used in connection with the optical sensors described herein.
Again, the foregoing examples of manners of combining the aspects of the present disclosure are non-limiting.
Having thus described several aspects and embodiments of the technology of this application, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those of ordinary skill in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the technology described in the application. For example, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the embodiments described herein. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described. In addition, any combination of two or more features, systems, articles, materials, kits, and/or methods described herein, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.
The above-described embodiments can be implemented in any of numerous ways. One or more aspects and embodiments of the present application involving the performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods. In this respect, various inventive concepts may be embodied as a computer readable storage medium (or multiple computer readable storage media) (e.g., a computer memory, one or more floppy discs, compact discs, optical discs, magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement one or more of the various embodiments described above. The computer readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various ones of the aspects described above. In some embodiments, computer readable media may be non-transitory media.
The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects as described above. Additionally, it should be appreciated that according to one aspect, one or more computer programs that when executed perform methods of the present application need not reside on a single computer or processor, but may be distributed in a modular fashion among a number of different computers or processors to implement various aspects of the present application.
Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.
Also, data structures may be stored in computer-readable media in any suitable form. For simplicity of illustration, data structures may be shown to have fields that are related through location in the data structure. Such relationships may likewise be achieved by assigning storage for the fields with locations in a computer-readable medium that convey relationship between the fields. However, any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish relationship between data elements.
When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers.
Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer, as non-limiting examples. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone or any other suitable portable or fixed electronic device.
Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible formats.
Such computers may be interconnected by one or more networks in any suitable form, including a local area network or a wide area network, such as an enterprise network, and intelligent network (IN) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks or wired networks.
Also, as described, some aspects may be embodied as one or more methods. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Elements other than those specifically identified by the “and/or” clause may optionally be present, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/779,691, entitled “OPTICAL TOMOGRAPHY SENSOR AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70000US00, which is herein incorporated by reference in its entirety. This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/779,831, entitled “OPTICAL COMPONENTS FOR OPTICAL TOMOGRAPHY SYSTEMS AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70001US00, which is herein incorporated by reference in its entirety. This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/779,421, entitled “DIFFUSE OPTICAL TOMOGRAPHY SYSTEMS AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70002US00, which is herein incorporated by reference in its entirety. This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/779,928, entitled “SUPPORTS FOR OPTICAL SENSORS AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70003US00, which is herein incorporated by reference in its entirety. This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/780,046, entitled “LINERS FOR OPTICAL TOMOGRAPHY SENSORS AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70004US00, which is herein incorporated by reference in its entirety. This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/780,535, entitled “OPTICAL TOMOGRAPHY SENSOR AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70005US00, which is herein incorporated by reference in its entirety. This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/780,595, entitled “OPTICAL TOMOGRAPHY SENSOR AND RELATED APPARATUS AND METHODS” filed on Mar. 13, 2013 under Attorney Docket No. C1369.70006US00, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61779691 | Mar 2013 | US | |
| 61779831 | Mar 2013 | US | |
| 61779421 | Mar 2013 | US | |
| 61779928 | Mar 2013 | US | |
| 61780046 | Mar 2013 | US | |
| 61780535 | Mar 2013 | US | |
| 61780595 | Mar 2013 | US |
