Patent Application
20160022182
This invention is generally in the field of medical devices, and relates to a probe device and a monitoring system utilizing such a probe device for carrying out measurements on a subject utilizing ultrasound tagging of light. The invention is particularly useful for monitoring various parameters, e.g. flow velocity and oxygen saturation in blood vessels, capillaries and venules, and oxygen saturation in deep tissues, such as brain, muscle, kidney and other organs.
Various techniques of non invasive monitoring of conditions of a subject have been developed. These techniques include impedance-based measurement techniques, photoacoustic measurements, acoustic measurements (Doppler measurements), and optical measurements (e.g. oxymetry).
Another approach, based on use of ultrasound tagging of light in measurements of various chemical and physiological parameters, has been developed and disclosed for example in WO 06/097910, WO 05/025399, and WO 2009/116029 all assigned to the assignee of the present application. According to the technique of WO 2009/116029, a probe assembly is used for monitoring one or more parameters of a subject, where the probe assembly comprises an acoustic port for transmitting acoustic radiation into a region of interest in the subject, at least one light output port for transmitting incident light towards the region of interest, at least one light input port for receiving light returned from the subject, and a control utility. The latter is configured for controlling at least one condition of a monitoring procedure and enabling the monitoring procedure upon detecting that said at least one condition is satisfied.
The present invention provides a novel probe assembly enabling effective attachment of the probe to the subject (i.e. allowing continuous monitoring of one or more conditions of a subject) and enabling the attachment part of the probe to be disposable.
The present invention takes advantage of the monitoring techniques utilizing the principles of ultrasound tagging of light, for example as disclosed in the above-indicated patent publications WO 05/025399, WO 06/097910, WO 2009/116029 assigned to the assignee of the present application. The probe assembly of the invention is thus configured and operable to irradiate a region of interest with acoustic waves while taking optical measurements on said region of interest.
The inventors have found that with such a probe assembly it is desirable to prevent generation of acoustic and light radiation at conditions other than a measurement session. More specifically, the probe assembly should be configured to enable self-monitoring of its position with respect to a subject, such that upon detecting that the probe assembly is properly attached to the subject's tissue, or that another predetermined condition exists, the probe assembly can be activated to take measurements.
Thus, the present invention, according to its one broad aspect, provides a probe assembly for use in monitoring one or more parameters of a subject. The probe assembly comprises at least one acoustic port for transmitting acoustic radiation into a region of interest in the subject, at least one light output port for transmitting incident light towards the region of interest, at least one light input port for receiving light returned from the subject, and at least one control mechanism.
In some embodiments of the invention, the probe assembly may comprise at least one acoustic port for receiving acoustic radiation from a region of interest in the subject. This may be implemented using the same acoustic port for both transmitting and receiving acoustic radiation, or by using separate acoustic ports for these functions. In the latter case, there are at least two acoustic ports included in the probe assembly, at least one for transmitting and at least one for receiving acoustic radiations.
The at least one control mechanism is configured for controlling a condition of coupling between the acoustic and light output ports and the subject, and controlling the operation of the probe (monitoring procedure) accordingly, e.g. preventing the probe assembly from operation upon identifying that said condition is not satisfied and/or alerting the operator that said condition is not satisfied and/or providing the operator with a quantitative measure of said conditions. Such control mechanism(s) may comprise at least a proximity sensing assembly, an attachment sensing assembly, or a signal quality sensing assembly.
It should be noted that the probe may be shifted between its operative and inoperative states, based on the control mechanism determination, either automatically, or upon user decision.
In some embodiments of the invention, the proximity sensing assembly of the control mechanism comprises a magnetic assembly, which may include a magnetic sensor (detector) and a magnet. The magnetic assembly may operate such that when the magnet is brought proximally to a detection range of the magnetic sensor corresponding to the condition of the desired coupling between the probe assembly and the subject, the magnetic field of the magnet is detected by the magnetic sensor allowing for the acoustic as well as the optical radiation to be safely activated, however, as long as the magnet is outside the detection region of the magnetic sensor the probe's operation is not allowed.
In some embodiments, in addition to or as an alternative to the magnet-based assembly, the control mechanism may include any other proximity detection assembly such as capacitive based assembly, as well as one or more other sensing assemblies, such as optical assembly, ultrasound distance sensing assembly, pressure measurement assembly, or RFID based assembly.
In some embodiments, the attachment sensing assembly of the control mechanism comprises a mechanical or electro-mechanical assembly that utilizes mechanical properties of the probe assembly in order to allow activation of the probe assembly (e.g. activation of the acoustic and/or optical radiation). In some embodiments, the probe assembly is configured as a two-part device, where the two parts are attachable/detachable between them. This enables one part, by which the probe assembly is brought in contact with the subject to be disposable, and enabling the other part to carry the elements of a measurement unit (acoustic and light ports/elements) and be thus a reusable part. It should be understood that in the single- or two-part design of the probe assembly, the probe assembly includes a so-called measurement and contacting/connecting portions, while in the two-part design these portions are attachable/detachable. In the description below these parts/portions are referred to as respectively reusable and disposable parts, but it should be understood that generally both may be disposable or reusable.
In some embodiments, the signal quality sensing assembly of the control mechanism comprises a light emitter (e.g. LED) that may be associated with a logic controller and may be used to wirelessly transmit information from the disposable part to the reusable part or to the control unit. The information may include a serial number for identification of the disposable part, an authentication signal for certifying that the disposable part is a certified one, a counter indicator for the amount of time since the activation of the disposable part, a signal indicating the degree of coupling between the reusable and disposable parts, a signal indicating the degree of coupling between the probe assembly (reusable and/or disposable parts) with the tissue. The information transmitted may also serve for carrying sensor information, e.g. output from optical detectors when positioned on the disposable part.
Thus, according to a first broad aspect of the invention, there is provided a probe for use in monitoring one or more parameters of a subject, the probe comprising: a monitoring assembly which comprises at least one acoustic port for transmitting acoustic radiation into a region of interest in the subject, at least one light output port for transmitting incident light towards the region of interest, at least one light input port for receiving light returned from the subject, and at least one control mechanism comprising at least one sensing assembly configured for sensing at least one of proximity, attachment and signal quality conditions, and being configured for controlling a condition of coupling between the probe assembly and the subject, thus enabling to control operation of the monitoring assembly, e.g. preventing its operation if the at least one condition is not satisfied.
The probe may include a first flexible portion, and a second portion on which the monitoring assembly is mounted, such that pressing the probe against the subject causes a deformation of the flexible portion, thereby reducing a distance between the monitoring assembly and the subject detectable by the proximity and/or attachment sensing assemblies.
The proximity sensing assembly may comprise a magnetic sensing assembly. Preferably, the magnetic sensing assembly comprises a magnet carried by the first flexible portion and a magnetic sensor located at the second portion, the magnetic sensor defines a sensing region in its vicinity and is configured for sensing a magnetic field of the magnet when the magnetic field overlaps with the sensing region. Alternatively or additionally, the proximity sensing assembly may comprise a pressure sensing assembly utilizing techniques known in the art, such as capacitive, resistive and electro-mechanical strain gauges.
The control mechanism may comprise the at least one proximity sensing assembly and the sensing assembly of a different type for controlling the condition of coupling between the probe assembly and the subject. Such at least two different sensing assemblies control the operation of the monitoring assembly, e.g. prevent the operation of the monitoring assembly as long as the coupling condition is not satisfied. In some embodiments, the coupling sensing assembly is a mechanical assembly, and in this case the mechanical assembly may include a switch located on a flexible portion, such that pressing the probe against the subject causes a deformation of the flexible portion thereby activating the switch to allow operation of the monitoring assembly.
According to some embodiments, the first and second portions of the probe are removably attachable to one another.
The flexible portion may be configured as a probe-subject adhesive unit being associated with a probe-subject adhesive media.
According to another broad aspect of the invention, there is provided a probe for use in monitoring one or more parameters of a subject, the probe comprising: a portion carrying a monitoring assembly configured for radiating the subject with acoustic and optical radiation, and a flexible portion by which the probe faces the subject when in operation, and at least one control mechanism comprising at least one proximity and/or attachment sensing assembly located at least partially on the flexible portion, such that pressing the probe against the subject causes a deformation of the flexible portion thereby reducing a distance between the monitoring assembly and the subject detectable by the at least one control mechanism, thereby enabling to control a condition of coupling between the probe and the subject to control operation of the monitoring assembly.
According to yet another broad aspect of the invention, there is provided a probe for use in monitoring one or more parameters of a subject, the probe comprising: a portion that carries a monitoring assembly and is configured for radiating the subject with acoustic and optical radiations, and a flexible portion by which the probe faces the subject when in operation; and at least first and second control mechanisms comprising at least first and second sensing assemblies respectively of same or different first and second types, each is independently operable to control a condition of coupling between the probe and the subject to prevent operation of the monitoring assembly if the at least first and second different sensing assemblies identify that the condition is not satisfied, wherein at least one of the at least first and second sensing assemblies is a proximity sensing assembly located at least partially on the flexible portion, pressing the probe against the subject causes a deformation of the flexible portion thereby reducing a distance between the monitoring assembly and the subject detectable by the at least one proximity sensing assembly.
In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:
a is a block diagram of an example of a probe assembly according to one aspect of the invention;
b is a block diagram of an example of a probe assembly according to another aspect of the invention;
c is a block diagram of an example of a probe assembly according to yet another aspect of the invention;
a and 9b show examples of the probe assembly comprising dual sensing mechanical assemblies located inside the probe assembly;
Referring to
The probe assembly 100 may be associated with a control unit 104, which is typically configured as a computing system and logic, and may include among other things a light source unit 104A and/or a detection unit 104B and/or an acoustic generator 104C (e.g. arbitrary waveform generator). Generally, the control unit 104 may be configured as an external unit as shown in
Preferably, a light guide connecting an external light emitter (e.g. in the control unit) and a light output port at the probe device is a small core fiber (e.g. a single-mode, a 50 μm or a 62.5 μm core fiber). As for a light guide connecting an external light detector (e.g. in the control unit) and a corresponding light input port at the probe device, it has an appropriate cross-sectional dimension of the core in order to satisfy the collection efficiency requirement. For example, a fiber or a fiber bundle, having a core of a diameter equal to or higher than 100 μm can be used. The maximal diameter and numerical aperture of a collecting fiber is determined so that the total path difference between light traveling in different paths in the fiber core is less than the coherence length of the light source. When the light source and/or detector forms an integral part of the probe 100, the optical fibers are eliminated. Electrical wires (or wireless means) are used to connect the probe 100 or the external control unit 104 with a monitor for displaying an image or data related to a diagnosis/monitoring procedure and/or the parameters chosen for carrying out the procedure.
The probe device 100 also includes an internal control utility 126. The control utility 126 may be configured generally similar to that described in the above-indicated patent publication WO 2009/116029 in that it is installed with appropriate electronic utility (coding chip operating with a unique activation code) allowing for identifying whether the probe assembly is a certified one (i.e. authentication procedure); and/or includes a memory unit adapted for recording data indicative of measurements taken on a specific subject during a certain period of time (thus enabling use of this data as a measurement history of the specific subject). Such data may serve as a measurement history of a specific subject, as a measure to record a duration of measurement or an expiration/prevention of use following a specific duration or date. The memory unit may also store data including information about the probe serial-number or any specific technical parameters that are relevant to the probe (e.g. calibration).
The probe device 100 may be configured as a two-part assembly, one part 110 carries the elements of the measurement/monitoring unit 102 and may be reusable, while the other part 150 by which the probe is brought in contact with the subject is configured to provide the desired coupling between the probe and the subject, as well as desired coupling with the reusable part 110, and may be disposable. The two parts 110 and 150 of the probe device are appropriately attachable/detachable to/from one another.
When performing measurements utilizing acoustic radiation, and especially ultrasound tagging of light, a sufficient degree of acoustic coupling between the acoustic port and the subject is needed, as well as certain degree of coupling between the subject and the output light port (to eliminate/reduce eye exposure to the light radiation), so as to actuate and operate measurements upon identifying that desired coupling has been established. According to the present invention, the probe device 100 includes an appropriately designed control mechanism 130, which is configured to satisfy the above two requirements, namely ensure that the measurement/monitoring unit 102 (i.e. reusable part 110) is properly attached to the other, contacting part 150 (disposable), and that said contacting part 150 and the measurement part 110 are attached to the subject under monitoring. To facilitate understanding, the top and bottom parts 110 and 150 of the probe 100 which are functionally different parts, so-called measurement and contacting parts, are referred to hereinbelow as respectively reusable and disposable parts, although it should be understood that generally both may be disposable or reusable.
The control mechanism 130 includes at least a first sensing assembly 140 (such as magnetic and/or optical and/or pressure-based, and/or mechanical and/or electrical and/or resistive etc.), and preferably also includes at least one additional independently operable sensing assembly 180 of the same or different type as the first sensing assembly. Thus, preferably, the control mechanism is a double-sensing mechanism where the two sensing assemblies operate independently, and the measurement procedure is allowed-actuated upon detection by both these assemblies that the proper coupling is achieved.
It should be clear, as can be seen in the
It should be noted that the invention is not limited to the specific configurations shown in the block diagrams of
Referring to
The reusable unit 110 may further include a strain relief member 114 which is configured for securing the connection and bending point of the reusable unit 110 with cables and/or fibers. Optical fibers as well as other cables pass through the member 114 and connect the light input/output ports and the acoustic port, all will be described below, with a proper light source, such as a laser, and an ultrasound transducer respectively. It should be understood that in some embodiments of the invention, the reusable unit 110 includes an ultrasound transducer, while in others it only includes an acoustic port responsible for passing the ultrasound radiation generated by a transducer located outside the reusable unit 110. Further shown in the figure is a strain relief cap 116 that may be used to lock the strain relief member 114. The cap 116 can be manufactured and assembled in various colors to indicate and mark various versions of the reusable unit 110.
The reusable unit 110 houses various functional elements/units which are not shown in the figure. As described above with reference to
The disposable unit 150 includes an attachment pad 152 (such as adhesive pad and/or strap) that assists in attaching the probe to the patient skin. The attachment pad 152 may be relatively wide. The attachment pad 152 may be made of a combination of a bio-compatible adhesive layer and a light blocking fabric layer, both enabling some degree of air ventilation to the patient skin. To support and provide additional ventilation, the pad 152 may include additional through-holes 154. The pad 152 is generally flexible and in order to enhance its flexibility and attachment to the patient's skin matching the curvature thereof, the pad may include additional through-cuts 156 around its circumference. The disposable unit 150 on the one hand serves as a secure support to the reusable unit 110, and, on the other hand serves as a coupler (as an adhesive) of the probe to the patient skin. To this end, the disposable unit 150 includes a support frame 160 which surrounds an opening configured in accordance with the geometry of the reusable unit to be placed therein. The frame 160 is formed with appropriate spaced-apart locking elements 162, 164 and 166 for holding the reusable unit 110 when placed in said opening. More specifically, the support frame 160 has front lock 162, side locks 164 and back supporters 166, which all together operate to position the reusable unit 110 securely and firmly, in place. The front lock 162 prevents a forward motion of the reusable unit 110, and also provides a counter-pressure to the front face of the reusable unit 110 when pushed against the patient tissue. The side locks 164 prevent movements of the reusable unit along the lateral axis (to the sides), and also lock and provide the major counter-pressure to the reusable unit when pushed against the patient tissue. The side locks 164 are preferably designed to enable easy attachment and a single hand removal of the reusable unit. The back supporters 166 prevent backward motion of the reusable part 110 and guide the reusable unit 110 into position when snapped into the disposable unit 150 as will be described further below.
As indicated above, the probe device includes the control mechanism including at least the magnetic sensing assembly 140. In
Turning to
According to this non-limiting embodiment of the invention, the bottom side of the housing of the reusable unit (e.g. the cover 112B) is configured to enable displacement/deformation of the cover when brought in contact with and pressed against the subject, such that the reusable unit moves towards the subject. To this end, the cover 112B is made of appropriate elastic/deformable material(s) (e.g. elastomeric materials such as rubber or silicone) and possibly also is geometrically designed (e.g. has somewhat curved outer surface) to enable slight movement into and out of the opening. As will be described further below, this configuration is aimed at enabling measurements only upon attaining the desired attachment of the reusable unit with the subject, identifiable by the double-assembly control mechanism. Thus, when the probe device is brought in contact with the subject and a mechanical pressure is applied, the reusable unit and accordingly the acoustic element (port/transducer) and the optical element (input light port(s)) are pushed towards the patient skin, thus providing desired attachment to allow a monitoring procedure to start. When the device is moved away from the subject, the bottom cover 112B returns to its initial shape (e.g. non-deformed state). It should be noted that, in some embodiments of the invention, the cover 112B might be constructed from a rigid/inelastic material being fixed in place, and no movement of the cover would be needed, e.g. if no mechanical micro-switch mechanism (marked 180 in the different figures) is used, or if the mechanical micro-switch mechanism is used in a different configuration being activated by another moving part.
The disposable unit is more specifically illustrated in
According to one possible embodiment, at least the magnet carrying portion 172D of the rod-like member 172A is made from an elastic/deformable material such that when the probe 100 is pressed against a subject, the magnet carrying portion deforms causing rotation of the magnet. Alternatively or additionally, the rod-like element 172A may be rotatable, and thus when the probe is brought to a subject's skin, the magnet carrying portion 172D is pushed causing rotation of the rod 172B which further contributes in the rotation of the magnet.
Thus, the magnetic assembly part 140A in the disposable unit 150 is configured such that a magnet therein is movable towards and away of the reusable unit and thus moves towards and away of a sensing element in the magnetic assembly part installed in the reusable unit. This movement of the magnet towards the reusable unit results in that the magnet 170 becomes located within a sensing region of the magnetic sensing element, which is located inside the reusable unit, thus indicating that the probe is close enough to the subject's skin, being one of the control mechanism conditions.
The first control mechanism is the magnetic (generally, proximity-type) sensing assembly 140 which includes the magnet 170 and the elastic magnet holder 172 located in the disposable unit 150, and a magnetic sensing element 142 located in the reusable unit 110 and being at the vicinity of the magnet 170 without physical contact between them. When the probe assembly 100 is not attached properly to the subject, the elastic magnet holder 172 remains in its deactivated position and turns down outside the disposable unit. As a result, the magnetic field of the magnet 170 is not detected by the magnetic sensor 142 and the latter thus does not generate an activating signal. On the other side, when the probe assembly is properly (securely) attached to the subject, the magnet holder 172 changes its orientation upwards into the activated position, as shown in
It should be noted that, generally, additionally or alternatively, the control mechanism may include any suitable proximity sensing assembly, such as capacitive, optical, ultrasound, mechanical micro-switch, pressure or RFID-based assembly. The construction and operation of such sensing assemblies are known per se and do not form part of the invention, and therefore need not be described in details.
The additional control mechanism may be the mechanical micro switch mechanism 180. This mechanism is located in the reusable unit 110 and includes a micro switch 182 and an elastic lever 184. The latter is located on the bottom cover 112B so as to be aligned with the micro switch 182. This mechanism utilizes the elasticity of the elastomeric bottom cover 112B. As shown in
Referring to
The disposable part 150A, shown in
Reference is made to
In this particular example, as shown in the figure, the controlling mechanism may include one or more of the following components: a light emitting element (e.g. LED) 190 with a logic element (microcontroller) 192 for controlling the light emitter; a power source 194 (e.g. a battery) for the light emitter and/or light detectors 140.1 and 140.2; a pressure sensor 196 and/or an ohmmeter 198 (or resistance meter or electrical current meter). The logic controller is configured to encode or convert signals that are transmitted by the lighting element according to a predetermined code.
The light emitter 190 with the associated logic controller 192 may be used to wirelessly transmit information from the disposable part to the reusable or the control unit (104). The information may include: a serial number for identification of the disposable part, an authentication signal for certifying that the disposable part is a certified one, a counter indicator for the amount of time since the activation of the disposable part (or the logic element), a signal indicating the degree of coupling between the reusable and disposable parts, a signal indicating the degree of coupling between the probe assembly (reusable and/or disposable parts) with the tissue, optical information detected by the light detectors, and more. This degree of coupling may be measured by the pressure sensor 196 or the ohmmeter 198, or any other proximity or attachment sensing assembly used in the invention or is known in the art, encoded by the logic controller to activate the lighting element, and transmitted optically to the control unit located internally or externally to the reusable part. This enables to transmit the information without wires or electrical connections that may unintentionally couple electric currents to the tissue, if not properly isolated. According to the invention, the same light detector may be used for receiving both of the information transmitted by the lighting element 190 and the optical signals that were emitted from the light output port 122. The operation of the lighting element may be synchronized with the operation of the light source included/connected to port 122. This synchronization can be done by firstly sensing by the light detectors on the disposable part that light is not emitted from port 122 and then triggering the operation of the lighting element 190 through the logic controller 192. Alternatively, a communication/synchronization signal can be emitted from light output port 122 to indicate that the light output port 122 will not operate for a specific period of time, allowing operation of the LED 190. It should be noted that the optical link achieved by the lighting element 190 and used for transmitting the information described above, may be substituted by other wireless links and technologies such as RF.
The pressure sensor 196 may be used instead or in addition to any of the previously mentioned proximity and/or attachment sensing assemblies. The pressure sensor 196 may be used for measuring and communicating the amount of pressure that the probe assembly applies on the tissue. The measured pressure is transmitted (through the operation of the lighting element 190 as described above) to the control unit. When the pressure is lower or higher than predetermined minimal or maximal thresholds, the logic controller 192 can display an alert to the user, or cease the operation of the probe assembly completely.
The ohmmeter 198 (or resistance/current meter) measures the resistance between the disposable part 150C and the tissue, or between sensing electrodes mounted on the disposable part, and sends a signal (e.g. through the operation of the lighting element 190) to the control unit. This signal can indicate the coupling between the probe assembly and the tissue, or the amount of gel, or any other coupling substance or media, positioned between the probe assembly and the tissue. When the resistance is lower or higher than predetermined min/max thresholds, the logic controller 192 can display an alert to the user, or cease the operation of the probe system completely.
In the examples above (e.g.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IL14/50280 | 3/13/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61782641 | Mar 2013 | US |
