Techniques disclosed herein generally relate to medicine delivery devices, and more specifically to techniques for measuring the dose of a medicine contained in a medicine delivery device.
Certain medical devices may be used to deliver a medicine to a user. An example of such a medical device is an injection device (e.g., a syringe, an injector pen, a hypodermic needle, etc.). The injection device may hold the medicine in a fluid form (e.g., liquid, gas, etc.) in a drug container (e.g., a cartridge), and the injection device may include a variable dose setting mechanism (e.g., a dial or knob) which may allow a user to set a dose of the medicine to be dispensed. The variable dose setting mechanism may have numerical markings on the injection device that allows the user to set the proper dose. After setting the dose, the user may operate the injection device to deliver the set dose of the medicine into a patient's body manually or automatically.
Although an injection device with a dose setting mechanism may provide the flexibility in setting a dose, the actual dose of the medicine being dispensed to the patient based on the dose set by the dose setting mechanism may be quite different from the desired dose. For example, the variable dose setting mechanism may not have the desired resolution or accuracy; the dose accuracy in the injection device may be susceptible to the mechanical accuracy of the cartridge; temperature and/or pressure changes may affect the actual dose of the medicine being dispensed to the patient. The dosing error may have some adverse effects on the patient. As such, it is desirable to accurately measure out the actual dose of the medicine in the medicine delivery device before, during, and after a drug dispensing.
Embodiments disclosed herein use distance measurement techniques to help determine the actual dose of the medicine to be, being, or been dispensed to a patient from a medicine delivery device.
In certain embodiments, a medicine delivery device is disclosed. The medicine delivery device may include a cartridge for storing a medicine, a needle assembly coupled to a bottom of the cartridge, a piston located in the cartridge for pushing the medicine to dispense the medicine from the cartridge through the needle assembly, and a sensor configured to measure a distance between the piston and the bottom of the cartridge. In various implementations, the sensor may include one or more of a triangulation-based distance measurement unit, a resonant frequency-based distance measurement unit, a time-of-flight-based distance measurement unit, a frequency-modulated continuous-wave time-of-flight-based distance measurement unit, a light intensity-based distance measurement unit, an electrical impedance-based distance measurement unit, an electrical capacitance-based distance measurement unit, or a strain sensor-based distance measurement unit.
In some implementations of the medicine delivery device, the sensor may include a triangulation-based distance measurement unit. The triangulation-based distance measurement unit may include a light source configured to transmit a light beam to illuminate at least a portion of an object, a photodetector array comprising a plurality of photodetectors, and optics for forming an image of the illuminated portion of the object onto the photodetector array, wherein the image of the illuminated portion of the object illuminates a portion of the photodetector array at a given time. The triangulation-based distance measurement unit may be located at the bottom of the cartridge, in the piston, or at another location in the medicine delivery device.
In some implementations of the medicine delivery device, the sensor may include a resonant frequency-based distance measurement unit. In some implementations, the resonant frequency-based distance measurement unit may include a transmitter configured to generate a plurality of transmission signal pulses for transmitting towards the bottom of the cartridge. The plurality of transmission signal pulses, when reflected at interfaces between the cartridge and the stored medicine, may cause a formation of a standing wave signal inside the cartridge. The resonant frequency-based distance measurement unit may also include a receiver configured to measure the standing wave signal. In some implementations, the resonant frequency-based distance measurement unit may include an ultrasonic resonant frequency-based distance measurement unit.
In some implementations of the medicine delivery device, the sensor may include a time-of-flight-based distance measurement unit, such as an ultrasonic time-of-flight-based distance measurement unit. In some implementations, the time-of-flight-based distance measurement unit may include a frequency-modulated continuous-wave time-of-flight-based distance measurement unit. In some implementations, the frequency-modulated continuous-wave time-of-flight-based distance measurement unit may include a transmitter configured to generate a frequency-modulated continuous-wave signal, where a frequency of the frequency-modulated continuous-wave signal varies with time. The frequency-modulated continuous-wave time-of-flight-based distance measurement unit may also include a detector configured to measure a beat frequency between the generated frequency-modulated continuous-wave signal and a previously generated frequency-modulated continuous-wave signal returned from an object.
In certain embodiments, a method of drug delivery measurement is disclosed. The method may include measuring, before a drug dispensing, a first distance between a dispensing piston and a bottom of a cartridge of a medicine delivery device that stores a medicine, and determining a volume of the medicine in the cartridge based on the measured first distance. In some implementations, the method may also include measuring, during or after the drug dispensing, a second distance between the dispensing piston and the bottom of the cartridge, and determining a dispensing rate or a volume of the dispensed medicine based on the first distance and the second distance. In some embodiments, measuring the first distance may include measuring the first distance using one or more of a triangulation-based distance measurement unit, a resonant frequency-based distance measurement unit, a time-of-flight-based distance measurement unit, a frequency-modulated continuous-wave time-of-flight-based distance measurement unit, a light intensity-based distance measurement unit, an electrical impedance-based distance measurement unit, an electrical capacitance-based distance measurement unit, or a strain sensor-based distance measurement unit.
In certain embodiments, an apparatus may include means for performing one or more of the functions described in the present disclosure. In certain embodiments, a non-transitory computer-readable medium may have instructions embedded thereon for drug delivery measurement, the instructions including computer code for performing one or more of the functions described in the present disclosure. In certain embodiments, a system may include modules that respectively perform one or more of the functions described in the present disclosure.
Embodiments of the disclosure are also directed to a medicine delivery device. In some embodiments, the medicine delivery device includes a shaft attached to a piston. The shaft may be configured to push the piston through a cartridge storing medicine to dispense the medicine from the cartridge through a needle assembly. In some embodiments, the medicine delivery device includes a sensor configured to measure a distance between the piston and a surface of the cartridge opposite the piston.
In various embodiments, the sensor includes a triangulation-based distance measurement sensor. In various embodiments, the triangulation-based distance measurement unit includes a light source configured to transmit a light beam to illuminate at least a portion of an object, a photodetector array comprising a plurality of photodetectors, and optics for forming an image of the illuminated portion of the object onto the photodetector array. The image of the illuminated portion of the object illuminates a portion of the photodetector array at a given time. In various embodiments, the triangulation-based distance measurement sensor is located at the bottom of the cartridge or in the piston. In various embodiments, the sensor includes a resonant frequency-based distance measurement sensor. In various embodiments, the resonant frequency-based distance measurement sensor includes a transmitter configured to generate a plurality of transmission signal pulses for transmitting towards the bottom of the cartridge. The plurality of transmission signal pulses, when reflected at interfaces between the cartridge and the stored medicine, may cause a formation of a standing wave signal inside the cartridge. In various embodiments, the resonant frequency-based distance measurement sensor further includes a receiver configured to measure the standing wave signal. In various embodiments, the resonant frequency-based distance measurement sensor includes an ultrasonic resonant frequency-based distance measurement sensor. In various embodiments, the resonant frequency-based distance measurement sensor is configured to form a standing wave in walls of the cartridge.
In various embodiments, the sensor includes a time-of-flight-based distance measurement sensor. In various embodiments, the time-of-flight-based distance measurement sensor includes an ultrasonic time-of-flight-based distance measurement sensor. In various embodiments, the time-of-flight-based distance measurement sensor includes a frequency-modulated continuous-wave time-of-flight-based distance measurement sensor. In various embodiments, the frequency-modulated continuous-wave time-of-flight-based distance measurement sensor includes a transmitter configured to generate a frequency-modulated continuous-wave signal. The frequency of the frequency-modulated continuous-wave signal may vary with time. In various embodiments, the detector may be configured to measure a beat frequency between the generated frequency-modulated continuous-wave signal and a previously generated frequency-modulated continuous-wave signal returned from an object. In various embodiments, the sensor includes a light intensity-based distance measurement sensor. In various embodiments, the sensor includes an electrical impedance-based distance measurement sensor. In various embodiments, the sensor includes an electrical capacitance-based distance measurement sensor. In various embodiments, the sensor includes a plurality of strain sensors distributed along the cartridge.
Embodiments of the disclosure are also directed to a method of drug delivery measurement. In some embodiments, the method may include obtaining first measurement data at a sensor. The first measurement data may be indicative of a first distance between a dispensing piston and a surface of a cartridge of a medicine delivery device. The surface of the cartridge may be opposite the piston. In some embodiments, the method may include providing the first measurement data to a processor of the medicine delivery device, and determining, using the processor, a volume of the medicine in the cartridge based on the measured first distance.
In various embodiments, the method may further include obtaining second measurement data at the sensor. The second measurement data may be indicative of a second distance between the dispensing piston and the surface of the cartridge. In various embodiments, the method may further include providing the second measurement data to the processor of the medicine delivery device, and determining, using the processor, a volume of the dispensed medicine based on the first distance and the second distance. In various embodiments, measuring the first distance involves measuring the first distance using at least one of: a triangulation-based distance measurement sensor, a resonant frequency-based distance measurement sensor, a time-of-flight-based distance measurement sensor, a frequency-modulated continuous-wave time-of-flight-based distance measurement sensor, a light intensity-based distance measurement sensor, an electrical impedance-based distance measurement sensor, an electrical capacitance-based distance measurement sensor, or a strain sensor-based distance measurement sensor.
In various embodiments, the medicine delivery device further includes a needle assembly coupled to a bottom of the cartridge, and a sensor configured to measure a distance between the piston and the bottom of the cartridge. The dispensing piston may be located in the cartridge and is configured for pushing the medicine contained in the cartridge to dispense the medicine from the cartridge through the needle assembly. In various embodiments, the sensor may be a resonant frequency-based distance measurement sensor including a transmitter configured to generate a plurality of transmission signal pulses for transmitting towards the bottom of the cartridge. The plurality of transmission signal pulses, when reflected at interfaces between the cartridge and the stored medicine, may cause a formation of a standing wave signal inside the cartridge. In various embodiments, the receiver may be configured to measure the standing wave signal. In various embodiments, the sensor may be a frequency-modulated continuous-wave time-of-flight-based distance measurement sensor that includes a transmitter configured to generate a frequency-modulated continuous-wave signal. The frequency of the frequency-modulated continuous-wave signal may vary with time. In various embodiments, the sensor may further include a detector configured to measure a beat frequency between the generated frequency-modulated continuous-wave signal and a previously generated frequency-modulated continuous-wave signal returned from an object.
In various embodiments, the method may further include continuously measuring a distance between the dispensing piston and the surface of the cartridge over a set time interval. In various embodiments, the first measurement data is obtained before a drug dispensing. In various embodiments, the second measurement data is obtained during a drug dispensing. In various embodiments, the second measurement data is obtained after a drug dispensing.
Embodiments of the disclosure are also directed to a medicine delivery device. In some embodiments, the medicine delivery device may include means for obtaining first measurement data. The first measurement data may be indicative of a first distance between a dispensing piston and a surface of a cartridge of a medicine delivery device. The surface of the cartridge may be opposite the piston. In some embodiments, the medicine delivery device may include means for determining a volume of the medicine in the cartridge based on the measured first distance.
In various embodiments, the medicine delivery device may further include means for obtaining second measurement data. The second measurement data may be indicative of a second distance between a dispensing piston and the surface of a cartridge of a medicine delivery device. In various embodiments, the medicine delivery device may further include means for determining a volume of dispensed medicine based on the first distance and the second distance. In various embodiments, the medicine delivery device may further include means for dispensing of medicine from the cartridge. In various embodiments, the medicine delivery device may further include means for pushing medicine contained in the cartridge to enable dispensing of medicine from the cartridge.
Embodiments of the disclosure are also directed to a non-transitory computer readable medium containing instructions. In some embodiments, the instructions, when executed by a processor of a medicine delivery device, cause the processor to: obtain first measurement data from a sensor. The first measurement data may be indicative of a first distance between a dispensing piston and a surface of a cartridge of a medicine delivery device. The surface of the cartridge may be opposite the piston. In some embodiments, the instructions, when executed by a processor of a medicine delivery device, cause the processor to determine a volume of the medicine in the cartridge based on the measured first distance. In some embodiments, the instructions, when executed by a processor of a medicine delivery device, cause the processor to obtain second measurement data from the sensor. The second measurement data may be indicative of a second distance between the dispensing piston and the surface of the cartridge. In some embodiments, the instructions, when executed by a processor of a medicine delivery device, cause the processor to determine a volume of the dispensed medicine based on the first distance and the second distance.
This summary is neither intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this disclosure, any or all drawings, and each claim. The foregoing, together with other features and examples, will be described in more detail below in the following specification, claims, and accompanying drawings.
Aspects of the disclosure are illustrated by way of example. In the accompanying figures, like reference numbers indicate similar elements.
Several illustrative embodiments will now be described with respect to the accompanying drawings, which form a part hereof. The ensuing description provides embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the embodiment(s) will provide those skilled in the art with an enabling description for implementing an embodiment. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of this disclosure.
A medicine delivery device may include a dose setting mechanism to allow a user to set a volume of a medicine to be dispensed to a patient. The actual dose of the medicine being dispensed to the patient based on the volume set by the dose setting mechanism may be quite different from the desired dose dispensed to the patient. For example, the dose setting mechanism may not have the desired resolution or accuracy; the dose accuracy in the medicine delivery device may be susceptible to the mechanical accuracy of the cartridge; and temperature and/or pressure changes may affect the actual dose of the medicine being dispensed to the patient. The dosing error may have some adverse effects on the patient. As such, there is a need to accurately measure out the volume of the medicine in the medicine delivery device before, during, and/or after a drug dispensing.
Disclosed herein are techniques to facilitate dispensing of a correct dose of a medicine to a user. The techniques may include determining a volume of the medicine in a cartridge before, during, and/or after a drug dispensing based on, for example, the time of flight, triangulation, or cavity resonant frequency technique, and using, for example, optical (e.g., infrared), ultrasonic, or radio frequency signals.
Medicine delivery device 110, which is described in more detail herein below, may be used to dispense a medicine to a patient. In the example of
Connecting device 130 may comprise any of a variety of electronic devices capable of receiving information from medicine delivery device 110 and communicating information to stakeholder(s) 160 via communication network 150. Connecting device 130 may include, for example, a mobile phone, tablet, laptop, portable media player, personal computer, or similar device. In some embodiments, connecting device 130 may comprise a specialized device for conveying information from medicine delivery device 110 (and possibly other medical devices) to stakeholder(s) 160. In some embodiments, connecting device 130 may comprise a device owned and operated by the patient (e.g., the patient's mobile phone). In other embodiments, the connecting device 130 may be owned and/or operated by another entity, such as a healthcare provider, insurance company, government agency, etc.
Connecting device 130 may execute an application to provide the data processing and/or relaying functionality illustrated in
Communication network 150 may comprise any of a variety of data communication networks, depending on the desired functionality. Communication network 150 may include any combination of radio frequency (RF), optical fiber, satellite, and/or other wireless and/or wired communication technologies. In some embodiments, communication network 150 may comprise the Internet and/or different data networks that may comprise various network types, including cellular networks, Wi-Fi® networks, etc. These network types may include, for example, a Code Division Multiple Access (CDMA) network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) network, a WiMax (IEEE 802.16), and so on. A CDMA network may implement one or more radio access technologies (RATs) such as cdma2000, Wideband-CDMA (W-CDMA), and so on. Cdma2000 includes IS-95, IS-2000, and/or IS-856 standards. A TDMA network may implement Global System for Mobile Communications (GSM), Digital Advanced Mobile Phone System (D-AMPS), or some other RAT. An OFDMA network may employ LTE (including LTE category M (Cat-M) or 5G), LTE Advanced, and so on. LTE, LTE Advanced, GSM, and W-CDMA are described in documents from 3GPP. Cdma2000 is described in documents from a consortium named “3rd Generation Partnership Project 2” (3GPP2). 3GPP and 3GPP2 documents are publicly available. The communication network 150 may additionally or alternatively include a wireless local area network (WLAN), which may also be an IEEE 802.11x network, and a wireless personal area network (WPAN) may be a Bluetooth network, an IEEE 802.15x, Zigbee® network, and/or some other type of network. The techniques described herein may also be used for any combination of wireless wide area network (WWAN), WLAN and/or WPAN.
Communication link 140 between connecting device 130 and communication network 150 may vary, depending on the technologies utilized by these components of the system 100. For embodiments where connecting device 130 is a smart phone capable of connecting with a cellular network and/or a Wi-Fi® network, communication link 140 may comprise a wireless communication link utilizing the mobile phone's cellular or Wi-Fi® functionality. In embodiments where connecting device 130 is a personal computer, communication link 140 may comprise a wired communication link that accesses communication network 150 via a cable or digital subscriber line (DSL) modem.
It is noted that some embodiments may not utilize a connecting device 130 to relay data to the communication network 150. In such embodiments, medicine delivery device 110 may connect directly to communication network 150 (as shown in
As noted above, stakeholder(s) 160 may include any of a variety of entities with an interest in the proper dispensing of medicine by medicine delivery device 110. This may include an individual practitioner (e.g., a doctor or nurse), a hospital, a drug manufacturer, an insurance provider (or other payer), a government agency or other health organization, and/or the like. In some embodiments, the user of medicine delivery device 110 (e.g., the patient) may also be a stakeholder 160 to which information regarding the use of medicine delivery device 110 is provided. Governmental health regulations and/or legal agreements between the patient and/or stakeholder(s) 160 may apply to the dissemination of information regarding the dispensing of a drug by medicine delivery device 110 to stakeholder(s) 160.
It will be understood, however, that medicine delivery device 110 illustrated in
Medicine delivery device 110 may include other devices to facilitate the dispensing of medicine. In the example of
Moreover, medicine delivery device 110 may include a communication interface 310 which may communicate using wireless and/or wired means (e.g., via wireless communication link 120 and/or 125 of
Although not shown in
In some implementations, body 210 may also hold various electronic units (not shown). The electronic units may include sensors, actuators, and processors of sensor(s) and actuator(s) 308. In some embodiments, the electronic units may include actuators to lock dispensing piston 402 (and/or shaft 404) at a fixed position to prevent dispensing piston 402 from pushing the medicine out of reservoir chamber 220. Moreover, the electronic units may include communication interface circuitries of communication interface 310. The communication interface circuitries may transmit information about the dosage setting, and receive a confirmation or overriding command to release the locking of dispensing piston 402 (and/or shaft 404), as described above.
One important aspect, for making sure that the right dose of the right drug is dispensed to the right patient at the right time via the right route, is to accurately measure the volume of the medicine in the cartridge to be dispensed or the volume of the medicine that has been dispensed from the cartridge of a medicine dilivery device. Example embodiments of various techniques for measuring the volume of the medicine in the cartridge to be dispensed, or various techniques for measuring the volume of the medicine that has been dispensed from the cartridge, are described in details below. In general, the volume of the medicine in the cartridge to be dispensed or the volume of the medicine that has been dispensed from the cartridge may be measured by measuring the distance or displacement of the dispensing piston from the bottom of the cartridge that is coupled to the needle assembly. For example, the distance between the dispensing piston and the bottom of the cartridge may be used to determine the volume of the medicine in the cartridge. The displacement of the dispensing piston before, during, or after a drug administration may be used to determine the volume of the medicine that has been dispensed during the drug dispensing.
Medicine delivery device 500 may also include an optical distance/displacement measurement unit for measuring the volume of the medicine in medicine delivery device 500. The optical distance/displacement measurement unit may include a light source 550 (e.g., an infrared LED or laser), optics 560, and a position sensitive detector (PSD) 570 (e.g., a pixel array). In the example shown in
In some embodiments, light source 550 may include a diode, an LED, or a laser, and it may emit a light beam, such as an invisible light beam in the infrared spectrum band. The light beam may be collimated and sent towards dispensing piston 520 to illuminate at least a portion of dispensing piston 520. The reflected light from the illuminated portion of dispensing piston 520 may be collected by optics 560 and imaged onto PSD 570. In other words, the illuminated portion of dispensing piston 520 may be imaged by optics 560 (which may function as a camera lens) onto PSD 570. PSD 570 may include an array of pixels that may detect light. The locations of the pixels that detect the image (e.g., a light spot) of the illuminated portion of dispensing piston 520 formed by optics 560 may indicate the position of the image on position sensitive detector 570. Light source 550, PSD 570, and the illuminated portion of dispensing piston 520 may form a triangle. If the emitted light beam is perpendicular to the line formed by light source 550 and PSD 570, a right angle triangle may be formed.
As also shown in
The optical distance/displacement measurement unit may continuously measure the distance between dispensing piston 520 and the inner bottom 512 of cartridge 510 before, during, and/or after a drug dispensing. For example, at time t1, dispensing piston 520 may be at position 1, and the light spot on PSD 570 may be at location A. At time t2, dispensing piston 520 may be at position 2, and the light spot on PSD 570 may be at location B. At time t3, dispensing piston 520 may be at position 3, and the light spot on PSD 570 may be at location C. A change in measured distance between two measuring time instants may indicate the volume of the medicine being dispensed between the two measuring time instants, and hence the dispensing rate. A change in measured distance before and after a drug dispensing may indicate the total volume of the medicine being dispensed to the patient.
As shown in
When wave signals (for example, acoustic signals such as ultrasonic signals) travel through a medium (i.e., traveling waves), they may be observed as waves with crests followed by troughs over a period of time. However, when the ultrasonic signals are incident on a mismatched boundary, the ultrasonic signals may be partially transmitted into the adjacent medium and partially reflected backwards, where the amount of reflection may be a function of the materials on the two sides of the boundary. For example, if a wave signal is traveling through a substantially solid medium and the adjacent medium is air, most of the wave signal may be reflected back into the solid medium due to the high level of impedance mismatch. On the other hand, when a wave signal is traveling through a first medium and the adjacent second medium is a medium having similar characteristics as the first medium, most of the wave signal may be transmitted into the second medium due to the close match. In any case, the reflected portion of the wave signal may interfere with consecutively generated wave signals in a given medium (e.g., a liquid) and produce an accumulated wave that may amplify over time, by the constructive interference of the plurality of signals over time.
With a proper selection of the excitation frequency for a given material and thickness, the transmitted signal (e.g., generated ultrasonic wave signal) and the reflected signal may interact in such a manner so as to constructively overlap with each other as they bounce between the boundaries of the medium, causing the ultrasonic wave to appear standing, which may be referred to as a standing wave, standing wave signal, or ultrasonic standing wave signal. Furthermore, with continued generation and application of the excitation signal pulses, the constructive transmitted and reflected signals may continue to add up in amplitude until an equilibrium value is approached. Thus, the medium and its adjacent mediums may form an acoustic cavity that exhibits resonance or resonant behavior for forming the standing wave signal at a particular frequency. An acoustic cavity may also be interchangeably referred to as an acoustic resonant cavity, a resonant acoustic cavity, a resonant cavity, an acoustic resonator or a cavity resonator, without deviating from the scope of the invention. An acoustic resonant cavity may have more than one resonant frequency. The resonant frequency may depend on the characteristics of the medium and the length of the cavity. Thus, the length of the resonant cavity may be determined based on the resonant frequency.
Medicine delivery device 700 may also include an ultrasonic distance/displacement measurement unit 750. Ultrasonic distance/displacement measurement unit 750 may be located in dispensing piston 720 or shaft 730. Ultrasonic distance/displacement measurement unit 750 may include an ultrasonic transmitter for generating ultrasonic signals at different frequencies and transmitting the ultrasonic signals through dispensing piston 720 towards the liquid medicine in cartridge 710. Ultrasonic distance/displacement measurement unit 750 may also include an ultrasonic receiver for measuring the returned ultrasonic signals or the ultrasonic signals at the boundary between the liquid medicine in cartridge 710 and dispensing piston 720 (or a bottom 712 of cartridge 710).
In some implementations, the ultrasonic transmitter of ultrasonic distance/displacement measurement unit 750 may gradually change the frequency of the transmitted ultrasonic signals until a resonant condition is detected. The frequency of the transmitted ultrasonic signals at the resonant condition may then be used to determine the length of the resonant cavity (i.e., the distance between piston 720 and bottom 712 of cartridge 710).
Even though ultrasonic signals are used in the above-described embodiment, a person skilled in the art would appreciate that other signals, such as optical signals, may also be used to form a resonant standing wave in the cavity within cartridge 710 for resonant frequency-based distance/displacement measurement. In some implementations, a standing wave may be formed in the cartridge housing/walls (e.g., due to the different impedances of the cartridge housing/walls with and without contacting the medicine fluid), rather than in the medicine from cartridge 710, for determining a distance between piston 720 and the bottom 712 of cartridge 710.
Furthermore, as described above with respect to
Another technique for distance/displacement measurement is to measure the time of flight (or round trip delay) for a wave signal (e.g., an acoustic signal or an electromagnetic wave signal, such as a light signal) to travel from a source to a target and then return from the target to the source (or a receiver near the source). The distance may therefore be given by the one-way time-of-flight multiplied by the speed of the wave signal traveling in the medium between the source and the target. Some time-of-flight sensors may operate by sending a series of short duration pulses to the target. Some time-of-flight sensors may use amplitude modulated continuous wave signals, and measure a phase shift in the modulation signal between the launched and the returned wave signals, and the time-of-flight may be determined by dividing the phase shift by the modulation frequency.
Medicine delivery device 800 may also include an ultrasonic transceiver 850 located in dispensing piston 820 or shaft 830. Ultrasonic transceiver 850 may include a transmitter and a receiver. The transmitter may transmit ultrasonic pulses towards dispensing piston 820 and a bottom 812 of cartridge 810. At least a part of the transmitted ultrasonic pulses may be reflected at the interface between dispensing piston 820 and the liquid in cartridge 810 due to impedance mismatch. At least some of the transmitted ultrasonic pulses may travel through dispensing piston to the liquid in cartridge 810, and then travel through the liquid in cartridge 810 before reaching bottom 812 of cartridge 810. Due to the impedance mismatch between the liquid in cartridge 810 and bottom 812 of cartridge 810, some portions of the ultrasonic pulses that have reached bottom 812 of cartridge 810 may be reflected back towards ultrasonic transceiver 850. Similar transmission and reflection may be experienced by the ultrasonic pulses on the return path. The receiver may detect the returned ultrasonic pulses and determine a time of flight (or round-trip delay) of the ultrasonic pulses in the liquid in cartridge 810 based on the detected signals and the transmitted ultrasonic pulses. The length of the cavity in cartridge 810 that is filled with the liquid medicine may then be determined based on the speed of the ultrasonic pulses in the liquid medicine.
A person skilled in the art would appreciate that other signals, such as waves in other frequency bands, may also be used to measure the length of the cavity in cartridge 810 that is filled with the liquid medicine. It may be difficult to accurately measure the time of flight using waves (e.g., optical waves) that may have a high propagation speed in the liquid medicine due to the relatively short length of the cavity in cartridge 810.
Furthermore, as described above, the time-of-flight-based distance/displacement measurement may be used to continuously measure the distance between dispensing piston 820 and the inner bottom 812 of cartridge 810 before, during, and/or after a drug dispensing. A change in measured distance between two measuring time instants may indicate the volume of the medicine being dispensed between the two measuring time instants, and hence the dispensing rate. A change in measured distance before and after a drug dispensing may indicate the total volume of the medicine being dispensed to the patient.
As discussed above, it may be difficult to accurately measure the time of flight using waves (e.g., optical waves) that may have a high propagation speed in the liquid medicine due to the relatively short length of the cavity in the cartridge. A frequency-modulated continuous-wave (FM-CW) technique, also called a continuous-wave frequency-modulated (CWFM) technique, is a short-range distance measuring technique. In a FM-CW time-of-flight based system, the transmitted signal may be a continuous wave with a known stable frequency (center frequency or carrier frequency) modulated by a modulation signal such that the frequency of the continuous wave varies up and/or down over a period of time. The modulation signal may be, for example, a sine wave, a sawtooth wave, a triangle wave, a square wave, or other signals. The frequency difference between the received signal and the transmitted signal at a given time instant may increases with the delay between the received signal and the transmitted signal, and hence may increase with the distance that the continuous wave travels. Thus, the travelled distance may be determined by mixing the transmitted signal with the received signal to produce a beat signal (demodulation), and measuring the frequency of the beat signal that may represent the frequency difference between the transmitted signal and the received signal.
where tf is the time of flight, as the received FM-CW wave at time instant t1 was generated at a time tf before time instant t1. Therefore, when the transmitted wave and the received wave are combined at (i.e., detected by) a detector, a signal with the beat frequency of Δf may be generated by the detector. The beat frequency may then be determined by various known methods. Based on the beat frequency and the chirp rate
the time of flight tf may be determined, which may then be used to determine the length of the cavity in the cartridge as in the time-of-flight-based distance/displacement measurement technique described above with respect to
It is noted that the above-described techniques for distance/displacement measurement are just some non-limiting examples. Other techniques, such as intensity-based techniques that may determine the length of the transmission path based on the attenuation of the transmitted signal, interferometer-based techniques, techniques using multiple wavelengths, techniques using optical fibers or fiber Bragg gratings, etc., may also be used to measure the dose of the medicine in a medicine delivery device or the dose of the medicine being dispensed from the medicine delivery device. For example, in some implementations, the electrical impedance of the cartridge housing (e.g., coated with a layer of conductive material) may depend on the area of the cartridge housing that is in contact with the medicine fluid, and thus may indicate the volume of the medicine in the cartridge. In some implementations, a pair of electrodes may be formed on the piston and the bottom of the cartridge, and a capacitance between the pair of electrodes may be measured to determine the distance between the piston and the bottom of the cartridge. In some implementations, a plurality of strain sensors distributed along the length of the cartridge may be used, and the total strains on the cartridge housing may be measured to determine the distance between the piston and the bottom of the cartridge.
At block 1010, a dose measurement unit (e.g., a distance/displacement measurement unit described above; as used herein, any reference to a dose measurement unit may be applicable to describe a distance measurement unit or a distance measurement sensor) or a sensor may obtain first measurement data indicative of a first distance between a dispensing piston and a surface of a cartridge opposite the piston (e.g., a bottom surface of the cartridge if the piston is attached to a shaft at the top of the cartridge) in a medicine delivery device that stores a medicine before a drug dispensing is performed. As described above, the first distance may be measured using triangulation-based measurement techniques, resonant frequency-based measurement techniques, time-of-flight-based measurement techniques, FW-CW time-of-flight-based measurement techniques, or other suitable techniques, such as intensity-based measurement techniques. The first distance may be measured more than one time, invalid or erroneous results may be removed, and valid results may be averaged to determine the actual volume.
Means for performing the function of block 1010 may include, for example, the dose measurement unit 314 shown in
At block 1020, the dose measurement unit or sensor may provide the first measurement data to a processor of the medicine delivery device.
Means for performing the function of block 1020 may include, for example, the dose measurement unit 314 shown in
At block 1030, a processor in communication with the dose measurement unit may determine a volume of the medicine in the cartridge based on the measured first distance. For example, if the dimensions of the cartridge (e.g., the radius or diameter of the inner cavity of the cartridge) are known, the volume of the medicine in the cartridge may be determined by the first distance and the area of the cross-section of the inner cavity of the cartridge.
Means for performing the function of block 1030 may include, for example, the hardware processor 312 shown in
At block 1040, during or after the drug dispensing, a dose measurement unit or a sensor may obtain second measurement data indicative of a second distance between the dispensing piston and the surface of the cartridge opposite the piston (e.g., a bottom surface of the cartridge if the piston is attached to a shaft at the top of the cartridge). may be measured by the dose measurement unit as described above with respect to block 1010. As described above, the second distance may be measured using triangulation-based measurement techniques, resonant frequency-based measurement techniques, time-of-flight-based measurement techniques, FW-CW time-of-flight-based measurement techniques, or other suitable techniques, such as intensity-based measurement techniques. The second distance may be measured more than one time, invalid or erroneous results may be removed, and valid results may be averaged to determine the actual volume.
Dispensing
Means for performing the function of block 1040 may include, for example, the dose measurement unit 314 shown in
At block 1050, the dose measurement unit or sensor may provide the first measurement data to a processor of the medicine delivery device.
Means for performing the function of block 1050 may include, for example, the dose measurement unit 314 shown in
At block 1060, the dose measurement unit or the computing system in communication with the dose measurement unit may determine a dispensing rate during the drug dispensingdispensing or a volume of the dispensed medicine based on the first distance and the second distance. For example, if the drug dispensingdispensing starts at time instant t1 and the second distance is measured at time instant t2, then the volume of the dispensed medicine may be determined based on the difference between the first distance and the second distance. The drug dispensing rate may be determined based on the volume of the dispensed medicine and the difference in time between time instant t1 and time instant t2.
Means for performing the function of block 1060 may include, for example, the hardware processor 312 shown in
It is noted that even though
The methods, systems, and devices discussed above are examples. Various configurations may omit, substitute, or add various procedures or components as appropriate. For instance, in alternative configurations, the methods may be performed in an order different from that described, and/or various stages may be added, omitted, and/or combined. Also, features described with respect to certain configurations may be combined in various other configurations. Different aspects and elements of the configurations may be combined in a similar manner. Also, technology evolves and, thus, many of the elements are examples and do not limit the scope of the disclosure or claims.
Terms “and,” “or,” and “an/or,” as used herein, may include a variety of meanings that also is expected to depend at least in part upon the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B, or C, here used in the exclusive sense. In addition, the term “one or more” as used herein may be used to describe any feature, structure, or characteristic in the singular or may be used to describe some combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example and claimed subject matter is not limited to this example. Furthermore, the term “at least one of” if used to associate a list, such as A, B, or C, may be interpreted to mean any combination of A, B, and/or C, such as A, B, C, AB, AC, BC, AA, AAB, AABBCCC, etc.
Reference throughout this specification to “one example,” “an example,” “certain examples,” or “exemplary implementation” means that a particular feature, structure, or characteristic described in connection with the feature and/or example may be included in at least one feature and/or example of claimed subject matter. Thus, the appearances of the phrase “in one example,” “an example,” “in certain examples,” “in certain implementations,” or other like phrases in various places throughout this specification are not necessarily all referring to the same feature, example, and/or limitation. Furthermore, the particular features, structures, or characteristics may be combined in one or more examples and/or features.
Specific details are given in the description to provide a thorough understanding of example configurations (including implementations). However, configurations may be practiced without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the configurations. This description provides example configurations only, and does not limit the scope, applicability, or configurations of the claims. Rather, the preceding description of the configurations will provide those skilled in the art with an enabling description for implementing described techniques. Various changes may be made in the function and arrangement of elements without departing from the spirit or scope of the disclosure.
Also, configurations may be described as a process which is depicted as a flow diagram or block diagram. Although each may describe the operations as a sequential process, many of the operations may be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may have additional steps not included in the figure. Furthermore, examples of the methods may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or microcode, the program code or code segments to perform the necessary tasks may be stored in a non-transitory computer-readable medium such as a storage medium. Processors may perform the described tasks.
For an implementation involving firmware and/or software, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory and executed by a processor unit. Memory may be implemented within the processor unit or external to the processor unit. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored.
If implemented in firmware and/or software, the functions may be stored as one or more instructions or code on a computer-readable storage medium. Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program. Computer-readable media includes physical computer storage media. A storage medium may be any available medium that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage, semiconductor storage, or other storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer; disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
In addition to storage on computer-readable storage medium, instructions and/or data may be provided as signals on transmission media included in a communication apparatus. For example, a communication apparatus may include a transceiver having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the claims. That is, the communication apparatus includes transmission media with signals indicative of information to perform disclosed functions. At a first time, the transmission media included in the communication apparatus may include a first portion of the information to perform the disclosed functions, while at a second time the transmission media included in the communication apparatus may include a second portion of the information to perform the disclosed functions
Having described several example configurations, various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the disclosure. For example, the above elements may be components of a larger system, wherein other rules may take precedence over or otherwise modify the application of the invention. Also, a number of steps may be undertaken before, during, or after the above elements are considered.
This application claims the benefit of U.S. Provisional Application No. 62/547,076, filed Aug. 17, 2017, entitled “DRUG DELIVERY MEASUREMENT IN A MEDICINE DELIVERY DEVICE” which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62547076 | Aug 2017 | US |