WO2022013858A1

WO2022013858A1 - Optical-based device and system for determining a physiological parameter of a subject

Info

Publication number: WO2022013858A1
Application number: PCT/IL2021/050845
Authority: WO
Inventors: Eldad Shemesh; Igor Kouperman; Boris Spektor
Original assignee: CardiacSense Ltd.
Priority date: 2020-07-12
Filing date: 2021-07-11
Publication date: 2022-01-20

Abstract

The present disclosure discloses, at some of its aspects, a device for a non-invasive measurement of physiological parameters of a subject. The measurement is performed by illuminating light towards a plurality of skin portions of the subject, typically skin portions of the wrist, and detecting the illumination response of said light from tissues under said skin portion to obtain respective detection data from each portion. The illumination to the plurality of portions is typically carried out simultaneously to obtain comparable measured data from each portion. The data that is detected from each portion is analyzed to identify the most informative detection data and utilize it to extract the physiological parameter of the subject that can include at least one of blood pressure, radial artery accurate location, SPO₂, heart rate and respiration rate.

Description

OPTICAL-BASED DEVICE AND SYSTEM FOR DETERMINING A PHYSIOLOGICAL PARAMETER OF A SUBJECT

TECHNOLOGICAL FIELD

The present disclosure is in the field of non-invasive devices for determining physiological data of a subject.

BACKGROUND To date, noninvasive measurement of a person’s hemodynamic parameters, such as blood pressure, has presented significant technical challenges. Monitoring vital parameters of a subject continuously during his/her daily routine can be very advantageous for identifying abnormal conditions at an early stage and such that the subject may be referred to receive essential medical care. Thus, the need of accurate and convenient to use noninvasive measurement devices are of need.

GENERAL DESCRIPTION

The present disclosure discloses, at some of its aspects, a device for a non-invasive measurement of physiological parameters of a subject. The measurement is performed by illuminating light towards a plurality of skin portions of the subject, typically skin portions of the wrist, and detecting the illumination response of said light from tissues under said skin portion to obtain respective detection data from each portion. The illumination to the plurality of portions is typically carried out simultaneously to obtain comparable measured data from each portion. The data that is detected from each portion is analyzed to identify the most informative detection data and utilize it to extract the physiological parameter of the subject that can include at least one of blood pressure, radial artery accurate location, SPO2, heart rate and respiration rate. An aspect of the present disclosure provides a device having at least one of the following three different combination of features:

The first combination provides a device for obtaining optical data indicative of at least one physiological parameter of a subject, through a skin area of a skin of the subject. The device includes a contact surface having a plurality of contact surface zones and configured to be brought into contact with said skin area and to change the contact surface shape to generally conform at least partially to the shape of the skin area. The device further includes a plurality of sensing modules having identical or correlated parameters, each sensing module being in fixed association with a corresponding contact surface zone and comprising: an illuminator having an illumination optical axis and configured to direct light to a unique region associated only with said module and spaced from the contact surface zone so that, when the contact surface zone is in contact with the skin area, the unique region is disposed farther from the contact surface zone than the skin area; a detector having a detector optical axis parallel to the illumination optical axis or forming an angle therewith and configured to detect light returned from said unique region and to generate based thereon, when the contact surface zone is in contact with the skin area, a signal suitable to be compared with signals obtained from the detectors of the other sensing modules based on the detection of light returned from their associated unique regions, so as to obtain said optical data.

The second combination provides a device for optical-based capturing of data indicative of at least one physiological parameter of a subject, through a skin area of a skin of the subject. The device includes a plurality of sensing modules, each of which comprises an illumination unit and a detection unit.

Each illumination unit includes an illumination contact element for contacting the skin such that the illumination contact elements defining jointly an illumination skin contact surface. The illumination unit further includes an illuminator having an illuminator optical axis and is configured to emit light in a direction of said optical axis onto an area of the skin. It is to be noted that the light penetrates the skin surface and interacts with tissues below the skin such as arterioles and is reflected therefrom. Each detection unit includes a detection contact element for contacting the skin such that the detection contact elements defining jointly an illumination skin contact surface. The detection unit further includes a detector having a detector optical axis. The detector is configured to detect at least one illumination response, e.g. wavelength, phase or intensity, an absolute value or a change of which, being correlated with said physiological parameter, and to generate, based thereon, data corresponding to the at least one physiological parameter.

In some embodiments of the second combination, the detector optical axis and the respective illuminator optical axis are parallel one to another. In some other embodiments, the detector optical axis and the respective illuminator optical axis are at an angle, e.g. an acute angle.

The third combination provides a device for obtaining optical data indicative of physiological parameters of a subject. The device includes a light source array that comprises a plurality of light sources. Each light source is fixedly associated with a respective light source skin contact surface for contacting the skin of the subject and is having a light source optical axis. Each light source is configured to provide illumination of at least one wavelength range towards a skin of the subject through said light source skin contact surface. Typically, the illuminated light is of the IR spectrum or the visible spectrum, e.g. green light or red light. The illumination is performed along said light source optical axis such that most the light penetrates through the skin and is reflected from tissues under the skin such as arteries, arterials, fat tissues, etc.

The device further includes a detector array that may be an array of discrete detectors, such as photodiodes or a pixel array of a CCD. The detector array includes a plurality of detectors, each detector is fixedly associated with a respective detector skin contact surface for contacting the skin of the subject and having a detector optical axis, typically the axis is normal to the detection plane of the detector. Each detector is configured to detect reflected light of a respective light source, defining together a sensing pair, namely a pair of light source and detector, and generate based thereon data pieces indicative of physiological parameters of the subject.

In some embodiments of the third combination, the light source optical axis and the detector optical axis forming an angle therebetween.

In some other embodiments of the third combination, the light source optical axis and the detector optical axis are parallel one to another. It is to be noted that the term illuminator is interchangeable with the term "light source" throughout the application.

The following embodiments can be applied to any of the above three combination of features of the device.

In some embodiments of the device the angle is maintained constant when the shape of the contact surface is changed.

In some embodiments, the device is configured to have a state, prior to its contact surface being brought into contact with said surface area, in which the contact zones associated with the illuminators lie in one plane and the contact zones associated with the detectors lie in another plane; the device further comprising a reference plane passing between the two planes, wherein the illumination device and the detector of each sensing module are disposed on different sides of the reference plane.

In some embodiments of the device, each of said sensing modules has a rear side at which it is mounted within the device and a front side fixedly associated with the contact surface.

In some embodiments of the device, the sensing modules are configured to change at least one of their orientation and position to provide the change of the shape of the contact surface.

In some embodiments, the device further includes a flexible substrate, wherein said sensing modules are fixedly mounted to said flexible substrate.

In some embodiments of the device, each sensing module is mounted to an individual substrate and the individual substrates of adjacent modules are connected to each other so as to allow their relative movement for providing the change of the shape of the contact surface.

In some embodiments of the device, the adjacent substrates are articulately connected to each other.

In some embodiments, the device further comprising a plurality of links each comprising one of the sensing modules.

In some embodiments of the device, said sensing modules constitute a part of a clip configured for being clipped to a band.

In some embodiments, the device further comprising a band to which said sensing modules are integrally mounted.

In some embodiments of the device, the band is a wristband. In some embodiments of the device, each of the illumination units of the sensing modules is configured to illuminate the unique regions with illumination comprising light of at least one wavelength from at least one of an IR or red wavelength ranges.

In some embodiments of the device, at least one sensing pair, or a group of several adjacent sensing pairs, is configured to move with respect to one or more different sensing pairs about at least a first axis so as to generally conform with the contour of the wrist of the subject. The light source and detector that constitute the sensing pair are typically integrally formed and configured to move together.

In some embodiments of the device, a group of two or more sensing pairs are formed on a flexible substrate that is allowing the movement with respect to one or more different sensing pairs, i.e. flexible PCB that is formed on a flexible surface.

In some embodiments of the device, an axis passing through the light source and the detector defining said first axis.

In some embodiments of the device each sensing pair is disposed on a single substrate that is movable with respect to one or more different substrates.

In some embodiments of the device, each substrate includes at least one hinge for allowing pivotal movement about a respective axis defined by the at least one hinge.

In some embodiments, the device further includes coupling elements configured for coupling two adjacent substrates through their respective hinges.

In some embodiments of the device, each substrate constitutes a link of a wristband, e.g. of a wristwatch.

In some embodiments of the device, the light source array is formed on one or more first flexible, generally planar, surfaces portion defined on said substrate and the detector array is formed on one or more second, generally planar, surfaces portion defined on said substrate. Each of said one or more first and the second surfaces portion defines a plane such that planes of respective light source and detector form substantial similar angle as said respective angle. Namely, the angle is substantially formed by the angle of the surfaces with respect to one another.

In some embodiments of the device, the one or more first and the second surfaces are integrally formed.

In some embodiments of the device, the one or more first and second surfaces constitute a part of a clip configured for clipping to a band. In some embodiments, the device further includes a clipping arrangement for clipping the device to a band.

In some embodiments of the device, the band is a wristband of a wristwatch.

In some embodiments of the device, the at least one wavelength range comprises green, red or IR wavelength.

In some embodiments, the device further includes a data transmission unit configured for transmitting the data or the data pieces, either through wired communication or wireless communication to a dedicated receiving client, e.g. a processor for further processing the data. The processor may utilize the data for comparing the signals from the detectors of the sensing modules.

In some embodiments of the device, the plurality of light sources are disposed along a light sources direction and the plurality of detectors are disposed along a detectors direction.

In some embodiments, the device further includes an artifact sensor/displacement sensor associated with said device and configured to identify movements of the device that are associated with artifact movements, thereby neglecting measurements performed during artifact movements.

In some embodiments, the device further includes an ECG sensor for measuring an ECG signal of the subject. The ECG signal may be used together with the optical data, namely PPG data, to determine the pulse transit time (PTT) or the pulse wave velocity (PWV). The PTT is calculated based on the difference between the 'R' signal of the ECG, and the systole time in the PPG, which is the time systole started at the measurement site. By determining an accurate value of the PTT, the blood pressure of the subject can be determined.

Another aspect of the present disclosure provides a system for determining at least one physiological parameter of a subject, e.g. for determining position of an artery and/or extracting physiological parameters of a subject therefrom. The system includes the device of any one of above described embodiments.

The system further includes a processor (interchangeable with the term "processing circuitry" throughout the application) configured for performing at least one of the following: receiving the signals from all the detectors, selecting from said signals those of at least one of the detectors, most suitable for determining the at least one physiological parameter, and using optical data obtained from the signals from the selected detector, to determine said at least one parameter; receiving said data pieces from each detector and analyzing the data pieces to extract one or more physiological parameters of the subject.

In some embodiments of the system, the processor is configured for scoring the detectors based on their associated signals and selecting at least one detector with a predetermined score for using optical data obtained from the signal of said detector for determining said at least one parameter.

In some embodiments of the system, the parameter is an accurate position of an artery.

In some embodiments, the system further includes a signaling device configured to provide a signal indicating the accurate position.

In some embodiments of the system, the physiological parameter is one or more of the following: blood pressure, SPO₂, heart rate, accurate position of an artery, e.g. the exact position of the artery with respect to the device/respective detector, and respiration rate.

In some embodiments of the system, the processing circuitry is configured for quality scoring each detector based on the quality of its respective data pieces and identifying a lead sensing pair including the detector with the highest score.

In some embodiments of the system, the processing circuitry is configured to extract said physiological parameters from the data pieces of said lead sensing pair.

In some embodiments, the system further includes a signaling device configured to provide a signal that identifies the lead sensing pair, e.g. by a visual signal.

In some embodiments, the system further includes an artifact sensor/displacement sensor associated with said device and configured to identify movements of the device that are associated with artifact movements, thereby neglecting measurements during artifact movements.

In some embodiments, the system further includes an ECG sensor for measuring an ECG signal of the subject, the processing circuitry is configured to receive said ECG signal and analyze it together with said data pieces to extract said one or more physiological parameters of the subject.

Another aspect of the present disclosure concerns an arm wrist arrangement that includes an engagement unit that comprises a sensor that is configured for measuring one or more biological parameters through a skin contact surface. Namely, the skin contact surface engages a skin portion of a subject, and the sensor obtains its measurements during the contact between the contact surface and the skin. The sensor may be configured as an optical-based or electrical based sensor.

Some measurements of such device require a very accurate and high-resolution positioning of the contact surface over a specific area of the skin surface of the subject, e.g. over the radial artery for obtaining an accurate measurement of the heart rate, breathing rate or blood pressure of the subject. To allow a high-resolution of positioning, the engagement unit is designed to be relatively small and protrude towards the skin surface of the subject when a measurement is carried out, which may be inconvenient over time for the subject. The arm wrist arrangement further includes a compressible member that surrounds the engagement unit and is configured to reduce the pressure that is applied by the contact surface on the skin surface of the subject upon contact.

Thus, a first aspect of the present disclosure provides an arm wrist arrangement that is configured to be worn on a wrist of a subject. The arm wrist includes an engagement unit that comprises a sensor having a contact surface that is configured to contact a measurement portion of the wrist of the subject, e.g. the skin portion over or at the vicinity of the radial artery. A compressible member is surrounding the engagement unit and having portions that are extending, in an uncompressed state, above the contact surface.

The compressible member is designed such that at least a portion thereof is configured to engage the wrist of the subject upon contact of the contact surface with the wrist of the subject, to reduce pressure applied between the contact surface and the measurement portion of the wrist.

The compressible member may be formed of rubber-based material, sponge-based material (e.g. polyester, polyurethane, vegetal cellulose) or a polymer.

In some embodiments, the compressible member is symmetrically disposed around said sensor. Namely, each portion of the compressible member at one side of the engagement unit has a corresponding, generally identical portion, at the other side of the engagement unit. In some embodiments, the compressible member has a concavely shaped cross- section. In some embodiments, the compressible member is concavely shaped, having an opening at its center that is configured to accommodate the engagement unit.

The contact surface spans a contact surface plane and at least a first portion of the compressible member is at one, facing out, side of the contact surface plane and a second portion is at the other, facing in, side of the contact surface plane. In other words, the compressible member has two opposite portions that extend above the contact surface and two opposite portions that are formed below the contact surface, at least in an uncompressed state.

In some embodiments of the arm wrist arrangement, the first portion of the compressible member that is extended above the contact surface has a smaller volume than the second portion, in an uncompressed state.

In some embodiments of the arm wrist arrangement, the contact surface is configured to move with respect to the contact surface, in response to pressure on the contact surface, at least along a vertical axis normal to a contact surface plane spanned by the contact surface. The arm wrist arrangement may include a flexible member that links the engagement unit to a support structure to allow the movement of the contact surface.

In some embodiments of the arm wrist arrangement, the compressible member is formed on a supporting structure that is a part of a wristband. In some embodiments, the flexible member links the contact surface or a body that is integral with the contact surface to the supporting structure.

In some embodiments of the arm wrist arrangement, the engagement unit has a frusto-conical shape, wherein the contact surface is the part of the frusto-conical with the smallest diameter. Such a shape may be advantageous for obtaining a high-resolution measurement of a specific skin portion with a relatively low irritating effect of the pressure applied by the engagement unit on the measured skin.

A measuring device, e.g. a wristwatch, may include the arm wrist arrangement of any one of its embodiments, as described above.

Yet, another aspect of the present disclosure concerns a device that is configured for (i) identifying a desired position for carrying out a measurement of a physiological parameter; and (ii) carrying out measurements that are indicative of the desired physiological parameter. The device includes two types of measuring units, the first for carrying out the measurement and at least one of a second measuring unit for performing the identification of the desired measuring location. The first measuring unit is configured for measuring data indicative of a physiological parameter of a subject from a desired location over the skin of the subject. The sensed data may be a displacement of a contact surface that engages the skin of the subject upon measurement, said displacement is indicative of activity of blood vessels at the proximity of the engaged skin portion. The at least one second measuring unit is configured for emitting light towards the skin portion and detect the light response, namely the reflection of the light from the skin portion. The detected intensity of the reflection is indicative of the relative location of the second measuring unit with respect to the desired measurement position. For example, when the desired measurement position is over the radial artery at the wrist of the subject, one or more second measuring units emit light towards the skin of the subject and detect the reflection therefrom. The measurement unit that detects a greater intensity reflected light is more proximate to the radial artery than all the others. The device also includes a signaling unit that is configured to exhibit a signal to the user that indicates the relative position of the first measuring unit based on the sensed data of the one or more second measuring units, namely indicates whether the user needs to move the first measuring unit, to which direction and to what extent in order to be over the desired measurement position, e.g. over the radial artery.

Therefore, another aspect of the present disclosure provides a device for measuring a physiological parameter of a subject. The device includes a measurement face and a first measuring unit having a contact surface at the measuring face and configured for contacting the subject's skin upon measurement, when the contact surface is brought into a desired measurement position on the skin, for measuring data indicative of the physiological parameter and generate physiological data. The device further includes at least one second measuring unit at the measurement face, laterally disposed to the contact surface of the first measuring unit, e.g. at the peripheral surrounding of the contact surface of the first measuring unit. Each second measuring unit includes an optical unit that is configured for emitting light toward the skin of the subject, detect the light response therefrom, e.g. reflection of the emitted light, and generate light data based on the detected reflection of light. A control unit is configured to receive and process the light data and generate position data indicative of a position of the contact surface with respect to a desired measurement position. In other words, the position data is indicative of whether, and to what extent, the device needs to be moved parallel to the measurement face, e.g. a plane spanned thereby, for bringing the contact surface to the desired measuring position, e.g. over an artery such as the radial artery or the carotid artery.

In some embodiments, the device further includes a signaling unit that is configured to receive the position data and to exhibit a signal indicative of the position of the contact surface with respect to the desired measurement position. Namely, the signaling unit exhibit an indication of a direction in which, and a distance to which, the device needs to be moved parallel to the measurement face for bringing the contact surface to the desired measurement position.

In some embodiments of the device, the first measuring unit includes a displacement sensor that is configured to sense the displacement of the contact surface along at least an axis normal to the measurement face. Namely, the contact surface displaces with respect to a housing of the device and upon application of pressure thereof, it moves into a confined space within the housing.

In some embodiments, the optical unit includes a light emitter configured to emit light of a wavelength range that has a relatively high light response from the desired measurement position, and a light detector configured to detect the light response of said light. In some embodiments, the desired measurement position may be over an artery, such as the radial artery, and the wavelength range of the emitted light is in the IR band. The wavelength range may be for example 780-950nm.

In some embodiments of the device, a distance between the optical unit and the contact surface does not exceed at least one of the following (the optical unit is disposed at the vicinity of the first measuring part): (i) a distance between the second measuring unit and a peripheral boundary of the measurement face; or (ii) a maximal dimension of the contact surface along the measurement face. Thus, the at least one second measuring unit is disposed at a certain known proximity to the contact surface such that light data obtained thereby is indicative of the position of the contact surface with respect to the desired measurement position.

In some embodiments of the device, the light data has a predetermined reference profile associated with different distances, at which the at least one second measuring unit can be disposed relative to the desired measurement position, and the control unit is configured to generate the position data based on comparison of the light data with the reference profile. In some embodiments, the control unit is configured to generate the position data indicative of the desired measurement position of the contact surface upon identifying a predetermined profile in the light data. For example, the control unit analyzes a magnitude profile of the reflection of the emitted light that is obtained by a plurality of second measuring units and identifies therefrom the proximity of each second measurement unit to the desired measurement position and hence determine the relative position of the contact surface with respect to the desired measurement position.

In some embodiments, the at least one second measuring unit is disposed at a lateral distance from the first measuring unit, e.g. from the center portion of the first measuring unit or from a peripheral portion thereof, that is less than an operative measuring area of the first measuring unit, namely, less than the maximal dimension of the contact surface.

In some embodiments, the device includes at least two second measuring units that are disposed at different locations at the measuring face and/or at different distances from the contact surface.

In some embodiments of the device, two or more of the second measuring units are disposed side by side along one linear axis or along each of at least two linear axes.

In some embodiments of the device, at least two of the second measuring units are disposed on one lateral side of the contact surface. In some embodiments, the at least two of the second measuring units are disposed on two lateral opposite sides of the contact surface.

In some embodiments, the control unit is configured to receive corresponding light data from each of the second measuring units and generate the position data based thereon.

In some embodiments, the device includes one or more wristband ports configured to receive a wristband, e.g. a wristwatch wristband, wearable on a wrist of the subject and to engage the wristband so as to allow the device to be slidingly moved therealong. In other words, the one or more wristband ports are configured for slidingly engagement with a wristband such that the device is slidable along the wristband.

In some embodiments of the device, two or more of the second measuring units are disposed side by side along one linear axis or along each of at least two linear axes, and wherein the linear axis, or at least one of the at least two linear axes, is oriented parallel or transversely with respect to a direction, in which the device is slidingly movable along the wristband. In some embodiments, the device includes a locking mechanism configured for locking the device at a position along the wristband. The position data may include data indicative of the desired position of the device along the wristband and the signaling unit is configured to exhibit a signal indicating said desired position along the wristband.

In some embodiments, the device includes the arm wrist arrangement of any one of the embodiments that are described with respect to the first aspect of the present disclosure.

In yet another aspect of the present disclosure provides a system that includes an array of two or more of any one of embodiments of the devices that are described with respect to the second aspect of the present disclosure. The system further includes a controller that is configured to receive the position data and the physiological data of each of the two or more devices and determine the physiological parameter based thereon.

In some embodiments of the system, the two or more devices are integral with a wristband of a wristwatch.

In some embodiments of the system, the controller is embedded within a housing of the wristwatch.

In some embodiments, the controller is configured to calculate weighting factor for each position data, based on its proximity to the desired measurement location, and to apply the calculated weighing factors on each of the respective physiological data to determine the physiological parameter. In other words, devices that are more proximate to the desired measurement location, based on the position data, receive a larger weighting factor and have a greater effect on the eventual calculated physiological parameter.

In some embodiments of the system, the controller is configured to identify the most proximate device to the desired measurement location and to determine the physiological parameter based on the physiological data retrieved from the respective device. Namely, the most proximate device is the only measurement that counts when determining the physiological parameter.

Furthermore, the present disclosure provides a system that includes any one of the embodiments of the arm wrist arrangement that are described with respect to the first aspect of the present disclosure and any one of the embodiments of the device that are described with respect to the second aspect of the present disclosure. EMBODIMENTS

The following are non-limiting embodiments of different aspects of the present disclosure: 1. A device for obtaining optical data indicative of at least one physiological parameter of a subject, through a skin area of a skin of the subject, the device comprising: a contact surface having a plurality of contact surface zones and configured to be brought into contact with said skin area and to change the contact surface shape to generally conform at least partially to the shape of the skin area; a plurality of sensing modules having identical or correlated parameters, each sensing module being in fixed association with a corresponding contact surface zone and comprising: an illuminator having an illumination optical axis and configured to direct light to a unique region associated only with said module and spaced from the contact surface zone so that, when the contact surface zone is in contact with the skin area, the unique region is disposed farther from the contact surface zone than the skin area; a detector having a detector optical axis forming an angle with the illumination optical axis and configured to detect light returned from said unique region and to generate based thereon, when the contact surface zone is in contact with the skin area, a signal suitable to be compared with signals obtained from the detectors of the other sensing modules based on the detection of light returned from their associated unique regions, so as to obtain said optical data.

2. The device of embodiment 1, wherein said angle is maintained constant when the shape of the contact surface is changed.

3. The device of embodiment 1 or 2, wherein the device is configured to have a state, prior to its contact surface being brought into contact with said surface area, in which the contact zones associated with the illuminators lie in one plane and the contact zones associated with the detectors lie in another plane; the device further comprising a reference plane passing between the two planes, wherein the illumination device and the detector of each sensing module are disposed on different sides of the reference plane. 4. The device of any one of embodiments 1 to 3, wherein each of said sensing modules has a rear side at which it is mounted within the device and a front side fixedly associated with the contact surface.

5. The device of embodiment 4, wherein said modules are configured to change at least one of their orientation and position to provide the change of the shape of the contact surface.

6. The device of embodiment 4 or 5, further comprising a flexible substrate, wherein said sensing modules are fixedly mounted to said flexible substrate.

7. The device of embodiment 4 or 5, wherein each sensing module is mounted to an individual substrate and the individual substrates of adjacent modules are connected to each other so as to allow their relative movement for providing the change of the shape of the contact surface.

8. The device of claim 7, wherein the adjacent substrates are articulately connected to each other. 9. The device of embodiment 7 or 8, further comprising a plurality of links each comprising one of the sensing modules.

10. The device of any one of embodiments 1 to 9, wherein said sensing modules constitute a part of a clip configured for being clipped to a band.

11. The device of any one of embodiments 1 to 9, further comprising a band to which said sensing modules are integrally mounted.

12. The device of embodiment 10 or 11, wherein the band is a wristband.

13. The device of any one of embodiments 1 to 12, wherein each of the illumination units of the sensing modules is configured to illuminate the unique regions with illumination comprising light of at least one wavelength from at least one of an IR or red wavelength ranges.

14. The device of any one of embodiments 1 to 13, comprising a data transmission unit configured for transmitting said data to a processor for comparing the signals from the detectors of the sensing modules.

15. A system for determining at least one physiological parameter of a subject comprising: the device of any one of embodiments 1 to 14; a processor configured for receiving the signals from all the detectors, selecting from said signals those of at least one of the detectors, most suitable for determining the at least one physiological parameter, and using optical data obtained from the signals from the selected detector, to determine said at least one parameter.

16. The system of embodiment 15, wherein the processor is configured for scoring the detectors based on their associated signals and selecting at least one detector with a predetermined score for using optical data obtained from the signal of said detector for determining said at least one parameter.

17. The system of embodiment 15 or 16, wherein said parameter is an accurate position of an artery.

18. The system of embodiment 17, further comprising a signaling device configured to provide a signal indicating the accurate position.

19. The system of any one of embodiments 15 to 18, wherein said physiological parameter is one or more of the following: blood pressure, SPO2, heart rate and respiration rate.

20. A device of any one of embodiments 1 to 15 or a system of any one of claims 15 to 19, further comprising an artifact sensor/displacement sensor associated with said device and configured to identify movements of the device that are associated with artifact movements, thereby neglecting measurements performed during artifact movements.

21. A device of any one of embodiments 1 to 15 or a system of any one of claims 15 to 20, further comprising an ECG sensor for measuring an ECG signal of the subject.

22. A device for optical-based capturing of data indicative of at least one physiological parameter of a subject, through a skin area of a skin of the subject, the device comprising: a plurality of sensing modules, each of which comprises an illumination unit and a detection unit, each illumination unit having an illumination contact element for contacting the skin, the illumination contact elements defining jointly an illumination skin contact surface, an illuminator having an illuminator optical axis and is configured to emit light in a direction of said optical axis onto an area of the skin, each detection unit having a detection contact element for contacting the skin, the detection contact elements defining jointly an illumination skin contact surface, a detector having a detector optical axis at an angle to the illuminator optical axis, the detector is configured to detect at least one illumination response being correlated with said physiological parameter, and to generate, based thereon, data corresponding to the at least one physiological parameter.

23. A device for obtaining optical data indicative of physiological parameters of a subject, the device comprising: a light source array that comprises a plurality of light sources, each is fixedly associated with a respective light source skin contact surface and is having a light source optical axis, each light source is configured to provide illumination of at least one wavelength range towards a skin of the subject through said light source contact surface; a detector array that comprises a plurality of detectors, each detector is fixedly associated with a respective detector skin contact surface and having a detector optical axis, each detector is configured to detect reflected light of a respective light source, defining together a sensing pair, and generate based thereon data pieces indicative of physiological parameters of the subject.

24. The device of embodiment 23, wherein at least one sensing pair is configured to move with respect to one or more different sensing pairs about at least a first axis.

25. The device of embodiment 24, wherein a group of two or more sensing pairs are formed on a flexible substrate allowing said movement.

26. The device of embodiment 24 or 25, wherein an axis passing through the light source and the detector defining said first axis.

27. The device of embodiment 24, wherein each sensing pair is disposed on a single substrate that is movable with respect to one or more different substrates.

28. The device of embodiment 27, wherein each substrate comprises at least one hinge for allowing pivotal movement about a respective axis defined by said at least one hinge.

29. The device of embodiment 28, comprising coupling elements configured for coupling two adjacent substrates through their respective hinges.

30. The device of any one of embodiments 27-29, wherein said substrate is being a link of a wristband.

31. The device of embodiment 25 or 27, wherein the light source array is formed on one or more first surfaces defined on said substrate and the detector array is formed on one or more second surfaces defined on said substrate, wherein each of said one or more first and the second surfaces defines a plane, planes of respective light source and detector form substantial similar angle as said respective angle.

32. The device of embodiment 31, wherein said one or more first and the second surfaces are integrally formed. 33. The device of embodiment 31 or 32, wherein said one or more first and second surfaces constitute a part of a clip configured for clipping to a band.

34. The device of any one of claims 23-33, comprising a clipping arrangement for clipping the device to a band.

35. The device of embodiment 34, wherein the band is being a wristband of a wristwatch.

36. The device of any one of embodiments 23-34, wherein the at least one wavelength range comprises green, red or IR wavelength.

37. The device of any one of embodiments 23-36, comprising a data transmission unit configured for transmitting said data pieces. 38. The device of any one of embodiments 23-37, wherein the plurality of light sources are disposed along a light sources direction and the plurality of detectors are disposed along a detectors direction.

39. The device of any one of embodiments 23-37, wherein the light source optical axis and the detector optical axis forming an angle therebetween. 40. A system comprising: the device of any one of embodiments 23-39; a processing circuitry configured for receiving said data pieces from each detector and analyzing the data pieces to extract one or more physiological parameters of the subject. 41. The system of embodiment 40, wherein the processing circuitry is configured for quality scoring each detector based on the quality of its respective data pieces and identifying a lead sensing pair including the detector with the highest score.

42. The system of embodiment 41, wherein the processing circuitry is configured to extract said physiological parameters from the data pieces of said lead sensing pair. 43. The system of embodiment 41 or 42, comprising a signaling device configured to provide a signal that identifies the lead sensing pair. 44. The system of any one of embodiments 40-43, wherein the physiological parameters are selected from any one of: blood pressure, accurate position of an artery, SPO2, heart rate and respiration rate.

45. The system of any one of embodiments 40-44, comprising an artifact sensor/displacement sensor associated with said device and configured to identify movements of the device that are associated with artifact movements, thereby neglecting measurements during artifact movements.

46. The system of any one of embodiments 40-45, comprising ECG sensor for measuring an ECG signal of the subject, the processing circuitry is configured to receive said ECG signal and analyze it together with said data pieces to extract said one or more physiological parameters of the subject.

47. An arm wrist arrangement configured to be worn on a wrist of a subject comprising: an engagement unit that comprises a sensor having a contact surface configured to contact a measurement portion of the wrist of the subject; a compressible member surrounding the sensor, having portions extending, in an uncompressed state, above the contact surface; wherein at least a portion of the compressible member is configured to engage the wrist of the subject upon contact of the contact surface with the wrist of the subject to reduce pressure applied between the contact surface and the measurement portion of the wrist.

48. The arm wrist arrangement of embodiment 47, wherein the compressible member is symmetrically disposed around said sensor.

49. The arm wrist arrangement of embodiment 47 or 48, wherein the compressible member is concavely shaped.

50. The arm wrist arrangement of any one of embodiments 47-49, wherein the contact surface spans a contact surface plane and at least a first portion of the compressible member is at one, facing out, side of said contact surface plane and a second portion is at the other, facing in, side of said contact surface plane.

51. The arm wrist arrangement of embodiment 50, wherein the first portion has a smaller volume than the second portion, in an uncompressed state. 52. The arm wrist arrangement of embodiment 50 or 51, wherein the contact surface is configured to move with respect to the compressible member, in response to pressure on the contact surface, at least along a vertical axis normal to a contact surface plane spanned by the contact surface.

53. The arm wrist arrangement of embodiment 52, comprising a flexible member associated with the engagement unit to allow the movement of the contact surface.

54. The arm wrist arrangement of embodiment 53, wherein the engagement unit and the compressible member are configured such that upon increase of the pressure on the contact surface, a greater portion of the compressible member is disposed at a facing in side of said contact surface plane than in a pressure-free state.

55. The arm wrist arrangement of any one of embodiments 47-54, wherein the compressible member is formed on a supporting structure that is being part of a wrist band.

56. The arm wrist arrangement of any one of embodiments 47-55, wherein the engagement unit is frusto-conical shaped.

57. A measuring device comprising the arm wrist arrangement of any one of claims 47-56.

58. The measuring device of embodiment 57, being a wristwatch.

59. A device for measuring a physiological parameter of a subject, the device having a measurement face and comprising: a first measuring unit having a contact surface at said measuring face and configured for contacting the subject's skin for measuring physiological data indicative of the physiological parameter, wherein the measurement is performed either (i) via the contact surface, or (ii) in response to movement of the contact surface in response to contact with the skin of the subject; at least one second measuring unit at said measurement face, and comprises an optical unit that is configured for emitting light toward the skin of the subject, detect the light response therefrom and generate light data based thereon; a control unit configured for receiving and processing said light data and generate position data indicative of a position of the contact surface with respect to a desired measurement position. 60. The device of embodiment 59, comprising a signaling unit configured to receive said position data and to exhibit a signal indicative of the position of the contact surface with respect to the desired measurement position.

61. The device of embodiment 59 or 60, wherein the first measuring unit comprises a displacement sensor configured to sense the displacement of the contact surface along at least an axis normal to the measurement face.

62. The device of any one of embodiments 59-61, wherein the optical unit comprises a light emitter configured to emit light of a wavelength range that has a relatively high light response from the desired measurement position, and a light detector configured to detect the light response of said light from the desired measurement position.

63. The device of embodiment 62, wherein said desired measurement position is above the radial artery of the subject and said wavelength range is in the IR band.

64. The device of embodiment 63, wherein said wavelength range is 700-950nm.

65. The device of any one of embodiments 59-64, wherein a distance between said optical unit and the contact surface at least does not exceed at least one of the following: a distance between the second measuring unit and a peripheral boundary of the measurement face; or maximal dimension of the contact surface along the measurement face.

66. The device of any one of embodiments 59-65, wherein said light data has a predetermined reference profile associated with different distances, at which said at least one second measuring unit can be disposed relative to the desired measurement position, and said control unit is configured to generate the position data based on comparison of the light data with the reference profile.

67. The device of any one of embodiments 59-66, comprising at least two second measuring units.

68. The device of embodiment 67, wherein the at least two second measuring units are disposed at different distances from the contact surface.

69. The device of embodiment 67 or 68, wherein two or more of said second measuring units are disposed side by side along one linear axis or along each of at least two linear axes.

70. The device of any one of embodiments 67-69, wherein at least two of said second measuring units are disposed on one side of the contact surface. 71. The device of any one of embodiments 67-70, wherein at least two of said second measuring units are disposed on two lateral opposite sides of the contact surface.

72. The device of any one of embodiments 67-71, wherein the control unit is configured to receive corresponding light data from each of the second measuring units and generate the position data based thereon.

73. The device of any one of embodiments 67-72, comprising a wristband port configured to receive a wristband wearable on a wrist of the subject and to engage the wristband so as to allow the device to be slidingly moved therealong.

74. The device of embodiment 73, wherein two or more of said second measuring units are disposed side by side along one linear axis or along each of at least two linear axes, and wherein the linear axis, or at least one of the at least two linear axes, is oriented with respect to a direction, in which the device is slidingly movable along the wristband.

75. The device of embodiment 73 or 74, wherein the device comprising a locking mechanism configured for locking the device at a position along the wristband. 76. A system comprising an array of two or more devices of any one of embodiments 59-75; and a controller configured to receive the position data and the physiological data of each of the two or more devices and determine the physiological parameter based thereon.

77. A system comprising an array of two or more devices of any one of embodiments 59-75; and a controller configured to receive the position data and the physiological data of each of the two or more devices and determine the physiological parameter based thereon, wherein the two or more devices are integral with a wristband of a wristwatch.

78. The system of embodiment 77, wherein the controller is embedded within a housing of the wristwatch.

79. The system of any one of embodiments 76-78, wherein the controller is configured to calculate weighting factor for each position data, based on its proximity to the desired measurement location, and to apply the calculated weighing factors on each of the respective physiological data to determine the physiological parameter. 80. The system of any one of embodiments 76-79, wherein the controller is configured to identify the most proximate device to the desired measurement location and to determine the physiological parameter based on the physiological data retrieved from the respective device. 81. The device of any one of embodiments 59-75 comprising the arm wrist arrangement of any one of embodiments 47-56.

82. A system comprising the arm wrist arrangement of any one of embodiments 47- 56 and the device of any one of embodiments 59-75.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. l is a block diagram of a non-limiting example of an embodiment of a device of the present disclosure. Figs. 2A-2D are illustrations of different views of a non-limiting example of the device of the present disclosure. Fig. 2A is a perspective view; Fig. 2B is a side view; Fig. 2C is a top view; and Fig. 2D is a bottom view of the device.

Figs. 3A-3B are block diagrams of non-limiting examples of different embodiments of a system according to an aspect of the present disclosure. Fig. 4A is a schematic plan view of a wrist of a subject/user with a schematic representation of a device according to one embodiment of the presently disclosed subject matter, disposed thereon;

Fig. 4B is an enlarged schematic partial cross-sectional view of the device and the wrist shown in Fig. 4A, taken along a plane A-A in Fig. 4A; Fig. 4C is a schematic cross-sectional view of a sensing module of the device shown in Fig. 4A, taken along a plane B-B.

Figs. 5A-5C are illustrations of different views of a non-limiting example of an embodiment of the arm wrist arrangement according to the present disclosure. Fig. 5A is a perspective view; Fig. 5B is a top view; and Fig. 5C is a side view of the arm wrist arrangement. Figs. 6A-6C are different views of non-limiting examples of an embodiment of a device for measuring a physiological parameter of a subject, which is configured for identifying a desired position for carrying out the measurement from a skin portion of the subject. Figs. 6A-6B are perspective views and Fig. 6C is a bottom view of the device.

Fig. 7 is a perspective view of non-limiting example of an embodiment of a wristwatch that includes the device of the present disclosure.

Figs. 8A-8B are perspective views of a non-limiting example of an embodiment of the device of the present disclosure, in which it includes a plurality of first measuring units. Fig. 8A shows the device alone and Fig. 8B shows the device coupled to a wristwatch.

DETAILED DESCRIPTION OF EMBODIMENTS

The present disclosure discloses a device configured for sensing data indicative of physiological parameters of a subject, e.g. blood pressure of the subject, in a non- invasive manner by using optical means. For example, the device is worn on a wrist of subject for measuring optical response signal from the radial artery to derive the blood pressure of the subject from said signal.

The device includes a plurality of sensing modules, each module is comprised of an illuminator having an illumination optical axis, and a light detector having a detector optical axis, e.g. a LED and a photodiode. Each unit of the sensing modules is associated with a respective contact surface, the contact surface is configured for being brought into contact with a skin surface area so as to allow (i) illumination of light by the illumination unit of each module via the skin towards a unique region located under the skin surface and (ii) detection of the light response from the unique region by the respective detector of the module. In order to increase the detection of the response signal from the unique region, the sensing modules are arranged such that the optical axes of each illuminator and its respective detector are tilted one towards the other to form an angle, e.g. an acute angle, between each two optical axes. Therefore, the unique region, e.g. a portion of the radial artery, is located between an illuminator and a detector of each sensing module.

It is to be noted that each detector may be paired with more than one illuminator, each of the associated illuminators may be configured to illuminate with light of a different wavelength. Each of the sensing modules are configured to conform with a different part of the contour of the skin than another module, while the geometrical parameters between members of the module, i.e. between an illuminator and a detector, remain substantially constant. In other words, each module has a degree of flexibility with respect to another module to conform with the contour of different parts of the skin.

The following figures are provided to exemplify embodiments and realization of the invention of the present disclosure.

Figs. 1 is a block diagram of a non-limiting example of an embodiment of the device according to an aspect of the present disclosure. The figure exemplifies a device 100 for obtaining optical data indicative of at least one physiological parameter of a subject, through a plurality of location along a curved skin area of a subject. The device 100 includes a contact surface 102 having a plurality of contact surface zones 103. The contact zones 103 are configured to be brought into contact with said curved skin area so as to allow a change of the contact surface 102 shape to conform at least partially to the shape of the curved skin area. a plurality of sensing modules 104i ("i=l,2,3,4,5,6...." and refers to an arbitrary identification number of a sensing module and its respective illuminator and detector) having identical or correlated parameters. Each sensing module 104i is in a fixed association with one or more corresponding contact surface zones 103, namely each member of the sensing module 104i is in a fixed association with a contact surface zone 103. The sensing module 104i includes an illuminator 106i having an illumination optical axis and configured to illuminate and direct light IL (li, Ii) to a respective unique region URi associated only with said module. The unique region URi is spaced from the contact surface zone so that, when the contact surface zone 103 is in contact with the skin area, the unique region is disposed further from the contact surface zone than the skin area, namely at a more distal location along the respective illumination axis than the skin area of the subject, e.g. a location under the skin of the subject. The sensing module further includes a detector 108i having a detector optical axis forming an angle, which can be an acute angle, with the illumination optical axis and configured to detect illumination response IR (lϊ, Ii) of light returned from said unique region URi and to generate based thereon, when the contact surface zone is in contact with the skin area, a signal suitable to be compared with signals obtained from the detectors of the other sensing modules based on the detection of light returned from their associated unique regions, so as to obtain said optical data.

The illuminators can illuminate with a wavelength from the visible spectrum and/or the IR spectrum. The specific wavelength may be selected according to the application of the device and/or parameters of the subject, such as skin color, age, etc.

The contact surface of the device may be continuous, in which contact zones that are associated with illuminators and/or detectors of different sensing modules are physically connected to one another, or discontinuous, in which contact zones that are associated with illuminators and/or detectors of different sensing modules are physically separated from one another.

In Figs. 1-4, like elements of different figures were given similar reference numerals shifted by the number of hundreds corresponding to the number of the respective figure. For example, element 202 in Figs. 2A-2D serves the same function as element 102 in Fig. 1.

Reference is now made to Figs. 4A and 4B, which illustrate a device 400 according to a one non-limiting embodiment of the presently disclosed subject matter, attached to a surface S of a wrist W of a user for obtaining, through a surface area SA thereof, measurable data indicative of an accurate position of the radial artery R of the user, and optionally, one or more of parameters which can be derived from the measurable data when the accurate position of the radial artery R is known such as, e.g. blood pressure, SPO₂, heart rate and respiration rate.

With reference to Fig. IB, the device 400 comprises a contact surface 402 configured to be brought into contact with the skin area SA disposed in the vicinity of the radial artery R, and an array of sensing modules 404 arranged side by side along an array direction AD, which is configured to be generally perpendicular to a longitudinal direction of the user’s arm and hand and thus to the radial artery R, when the device 400 is attached to the wrist of a user.

The contact surface 402 can be continuous with the contact zones 403 of different modules having no spacing therebetween (as shown in Figs. 4A and 4B ), or discontinuous with the contact zones being separated from one another along the direction

AD

It should be indicated that, whilst in the present embodiment the device 400 is configured to be attached to a wrist of a user, a similar device according to the presently disclosed subject matter can be configured for being attached to any other part of a user’s body for obtaining measurable data indicative of at least one physiological parameter of a user through a corresponding skin area thereof, as long as it is possible to bring the contact surface of the device into contact with this skin area.

Each sensing module 404 is fixedly associated with at least one respective contact surface zone 403 of the contact surface 402 and is configured to obtain a measurable response signal from a unique region UR associated only with this module and disposed at a pre-determined distance d from the respective contact surface zone 403.

In the present embodiment, this distance d corresponds to an average depth at which the radial artery R is known to be disposed relative to the skin S and the extension of the unique region in the directions AD corresponds to an average cross-sectional dimension of the radial artery. However, the distance d and the extension of the unique region UR can vary when a device according to the presently disclosed subject matter is configured for an application other than that described above.

In general, sensing modules of a device according to the presently disclosed subject matter can have identical or correlated parameters so as to allow measurable response signals produced thereby to be compared with each other. In the present embodiment, this can allow distinguishing a signal obtained from the unique region coinciding or overlapping with the radial artery from those obtained from other unique regions.

A device according to the presently disclosed subject matter can comprise at least one data transmission unit configured for transmitting signals corresponding to the measurable data to a processing circuitry for comparing between the signals from different sensing modules. The data transmission unit can be common for all the sensing modules e.g. such as that designated as 418 in Fig. 4A, or each of the modules can be associated with its own data transmission unit.

A device according to the presently disclosed subject matter can further comprise a control system configured to control its operation. The control system can comprise at least one PCB to which the sensing modules are mounted. This can be a single flexible PCB to which all the modules are mounted, or each module or a group of modules can be mounted to a separate PCB.

Reverting to Fig. 4A, the device 400 has a plane RP parallel to the array direction AD and dividing all the sensing modules into two parts, a part 404’ disposed adjacent the user’s hand, and a part 404” disposed adjacent the user’s arm, when the device 400 is worn on the wrist of a user. The contact zones 403 of the two parts of the sensing modules 404 can constitute a common continuous contact surface or the contact surface portions of each part can constitute a continuous contact surface portion spaced from that of the other part. These portions are designated as contact zones 403’ and 403” in Fig. 4C of the parts 404’ and 404”, respectively, and they are shown there as being spaced apart in the direction perpendicular to the array direction AD.

The reference plane RP intersects the contact surface 402 of the device 400 along a contour line C defining the shape of the contact surface 402. In this connection it should be understood that if the contact surface 402 is constituted by a number of contact surface zones which are spaced apart from each other, the contact surface 402 will be represented by an envelope of all the contact surface zones, and the contour line C will be represented by an intersection of the reference plane RP with such an envelope or by an intersection of a plane parallel to the reference plane with the a maximal number of the contact zones along the array direction AD.

In accordance with the presently disclosed subject matter, the contact surface 402 is configured to change its shape, and thus the shape of the contour line C along the array direction AD, so that when the contact surface is brought into contact with the skin area SA, it at least partially conforms thereto. This can be achieved by the contact surface zones 403 of different modules, or the modules themselves together with their contact surface zones, being configured to change at least one of their orientation and position relative to that/those of the adjacent modules, to bring the shape of the contact surface 402 into at least partial conformity with the shape of the skin area SA.

In the latter of the above options, all sensing modules of a device according to the presently disclosed subject matter can be mounted at their rear side to a common flexible substate (not shown in Figs. 4A to 4C), with a possibility to change at least one of their orientation and position in order to correspondingly change the orientation and/or position of their contact surface zones so as to bring the shape of the contact surface into conformity with a skin surface area to which the device is to be attached. Alternatively, each sensing module can be mounted to its individual substrate and the individual substrates of adjacent modules can be connected to each other so as to allow their relative movement for providing the above change of the shape of the contact surface. In this case, the sensing modules with their substrates and contact surface zones can, for example, be hingedly/pivotably connected to each other, e.g. along an axis perpendicular to the array direction AD of the device.

In general, the sensing modules of a device of the presently disclosed subject matter can be of any kind suitable to provide measurable data indicative of the physiological parameter of a user that needs to be determined. In the present embodiment as well as further embodiments described hereinbelow, the sensing modules are configured to provide optical data and thus each comprise an illuminator positioned in one of the above two parts of the module and a detector positioned in the other part of the module. The illuminator is configured to direct light to the unique region UR and spaced from the contact surface zone thereof so that, when the contact surface zone is in contact with the skin area, the unique region is disposed further from the contact surface zone than the skin area and a detector positioned in the other part. The detector is configured to detect light returned from the unique region and to generate based thereon, when the contact surface zone is in contact with the skin area, a signal suitable to be compared with signals obtained from the detectors of the modules based on the detection of light returned from their associated unique regions, so as to obtain optical data indicative of at least one physiological parameter of a user as described above.

The illuminators of all the sensing modules and the detectors of all the sensing modules can be positioned at different sides of the reference plane RP of the device, e.g. all the illuminators can be positioned at one side of the reference plane and all the detectors - at the other side thereof. Such arrangement can facilitate controlling the operation of the illuminators and the detectors. In particular, the control system can comprise two PCB substrates, one - to which all the illuminators are mounted and the other - to which all the detectors are mounted.

The processor/processing circuitry can use the optical data from all the detectors or the optical data of one or more selected detectors to extract the physiological data. The processor can be configured for scoring the optical data of each detector and select one or more optical data sets of the highest scored detectors and determine the physiological data of the subject based thereon.

Fig. 4C schematically illustrates one of the sensing modules designated as 404i, comprising a sensing pair including an illuminator 406i configured to direct light to the unique region URi and a light detector 408i configured to detect light response from the unique region and to generate based thereon a signal suitable to be compared with signals obtained from the detectors of the other sensing modules based on the detection of light returned from their associated unique regions, so as to obtain the optical data.

The illuminator and the detector are disposed at different sides of the reference plane RP passing between their respective optical axes IOA and DOA and they are so oriented as to form an angle a between these axes. The angle can be fixed or adjustable, if desired, to increase or reduce the distance from the contact surface to the associated unique area.

Each of the illuminator and the detector has a rear side at which it is held in place in the device 400 and a front side with the associated respective contact surface zone 503f and 403i", respectively, which is integrally connected thereto.

All the sensing modules 404 have the same general construction as the module 404i, and technical characteristics of all the modules including parameters of their contact surface zones and their unique regions are identical or correlated in order to allow optical response signals produced thereby to be compared.

The illuminators of the sensing modules can be in the form of LEDs and can provide light of a wavelength from the visible spectrum and/or the IR spectrum. The specific wavelength may be selected according to the application of the device and/or parameters of the subject, such as skin color, age, etc. In the device 400 of above described embodiment, the illuminators can be configured to produce illumination comprising light of at least one wavelength from at least one of an IR or red wavelength ranges. Each sensing module can include more two or more illuminators providing light of different characteristics, e.g. different wavelengths.

The detectors of the sensing modules can each be in the form of any suitable sensor, e.g. a photodiode configured to detect light of the selected wavelength and to generate based thereon, when the contact surface zone is in contact with the skin area, a signal suitable to be compared with signals obtained from the detectors of the other sensing modules based on the detection of light returned from their associated unique regions, so as to obtain said optical data.

A device according to the presently disclosed subject matter can be in the form of an stand-alone appliance configured to be brought into contact with a user’s wrist only when it is occasionally desired to make the measurements, or it can be configured for wearing by a user during a prolonged period of time. In the latter case, the device can be configured for mounting to a wristband or for being formed integrally therewith, and for being held in contact with the wrist of a user as long as needed for its use.

Figs. 2A-2D are illustrations of different views a non-limiting example of an embodiment of the device according to an aspect of the present disclosure. The device 200 includes a plurality of sensing modules 204i, in this non-limiting example four sensing modules. Each sensing module 204i may include more than one illuminator and each illuminator may be configured to illuminate with a different wavelength.

In the example of Figs. 2A-2D, each sensing module includes two members, a single illuminator 206i and a single detector 208i. Each illuminator 206i has an illumination optical axis IOA and each detector 208i has a detector optical axis DOA, as can be seen in Fig. 2B. The optical axes of each two members of a sensing module intersect to form an angle a therebetween. The angle may adjustable, e.g. by disposing the members on one or more flexible substrates that can bend by application of force thereon to thereby change the angle. The illuminator 206i and the detectors 208i are each arranged along an array direction AD.

In Figs. 2A-2D, the angle a between the optical axes of each two members of a sensing module 204i is maintained substantially constant, namely the illuminator 206iand the detector 208i do not move with respect to one another and are fixedly mounted on a relatively rigid substrate 210i that generally maintains its shape.

The substrates may have a contour to conform with the curved skin portion of the subject and are typically identical. The substrates may have a concave cross section portion, wherein one side of the slope including the illuminator and the other side including the detectors. In some embodiments, the substrates may have a generally "V" cross section portion that, wherein one side of the slope including the illuminator and the other side including the detectors. The substrates 210i extend along a substrate direction SD, which is perpendicular to the array direction AD and to the reference plane RP, and they are pivotably connected to each other to pivot about an axis P parallel to the substrate direction SD.

The device 200 includes a contact surface 202 that is constituted by a plurality of discontinued contact surface zones 203. It should be noted that the contact surface 202 encompasses any part of the sensing modules that is intended to be brought into contact with the skin of the subject. Each illuminator 206i and detector 208i is fixed at a with a single contact surface zone 203 that is configured for contacting a respective skin area (not shown) to illuminate or detect therethrough, respectively. In some embodiments, the contact surface zones may also serve as protective barriers for the electronic components of the member. Each illuminator and detector, together with their respective contact surface zone, defining an illumination unit and detection unit, respectively.

A reference plane RP intersects with the substrates 210i along a central line such that the illuminator 206i are disposed at one side of the reference plane and the detectors 208i are disposed at a second side of the reference plane, as can be best seen in Fig. 2C.

Each sensing module may be disposed on an individual substrate that has at least one degree of freedom for changing at least one of its orientation and/or position to provide the change of the shape of the contact surface. The degree of freedom may allow the rotation with respect to at least one another substrate thereby allowing to conform with the shape of the curved skin surface of the subject. Alternatively, the sensing modules may be disposed on a different substrate portion of a continuous substrate and each substrate portion has s degree of freedom for changing at least one of its orientation and/or position to provide the change of the shape of the contact surface. The degree of freedom may allow the rotation with respect to another portion, e.g. by flexible linking sections linking adjacent substate portions or by weak linking sections defined by a weaker material section linking two adjacent substrate portions.

For example, each sensing module may be disposed on a different substrate 210i such that each two adjacent substrates are linked to one another by a linking portion 212, as can be best seen in Fig. 2D. Thus, each sensing module 204i is practically a link and all the links together constitute the device 200.

Each illuminator and each detector may be controlled and operated by a separate PCB that may be controlled by a central or distributed processing circuitry. Namely, each illuminator and each detector are connected to a single PCB. In some embodiments, two or more illuminator are connected to a first single flexible PCB and/or two or more detectors are connected to a second single flexible PCB. The flexible PCBs are configured for allowing the sensing modules to bend and conform with the contour of the shape of the curved skin of the subject.

The sensing modules can be attached or associated with a wristband to be placed around the wrist of a subject when the wristband is worn for identifying the location of the radial artery and/or obtain physiological data by sensing optical data therefrom. The entire device may include the wristband or may be integrated in the wristband or clipped thereto. The device may be designed as a clip configured to be clipped to a wristband, e.g. a wristband of a wristwatch. For example, as exemplified in Figs. 2A-2D, the sensing modules 204i are disposed on substrates 210i that are linked to one another that constitute the device, each substrate including one or more clipping portions 214i that constitute a part of a clipping arrangement 216 configured for clipping the device 200 to a wristband (not shown).

The optical data of the received signals that is collected by each detector is transmitted to a processing circuity, i.e. a processing unit, so as to be analyzed to thereby extract physiological data therefrom, e.g. a location of the radial artery and/or physiological data indicative of physiological parameters of the subject, such as blood pressure. The optical data from each detector may be transmitted, in wired or wireless means, directly to the processing circuitry or via a transmitting unit that transmits all the data of the detectors to the processing circuitry.

For example, each detector 208i is in data communication with a respective transmitting unit 218i that is configured to transmit the optical data of the received signals being collected by the respective detector 208i.

Another aspect of the present disclosure provides a system for determining at least one physiological parameter of a subject. The system includes a device according to any of the embodiments described above having a plurality of sensing modules. The system further includes a processing circuitry configured for receiving the optical data from one or more detectors and extract the physiological data of the subject therefrom.

Any one of the devices 100 and 200 described above, as well as any other device according to presently disclosed subject matter, can constitute a part of a system further comprising a processor/processing circuitry configured for receiving the signals from all the sensing modules, selecting from these signals the most suitable ones for determining the desired physiological parameter/s, and using the data obtained from the signals from the selected module for determining the parameter/s. The data can be transmitted to the processing circuitry from the data transmission unit or directly from the sensing models, in wired or wireless manner.

Optionally, the processor can be configured for scoring the sensing modules based on their associated signals and selecting at least one module having a score that satisfies a certain condition for using data obtained from the signal of such module for determining said at least one parameter. As indicated above, the physiological parameter which can be measured by a system using a device according to the presently disclosed subject matter, can be one or more of blood pressure, SPO2, heart rate, respiration rate and/or the accurate position of an artery, such as the radial artery of the subject. The system can indicate the position of the radial artery either by signaling a location over the wrist of the user or by indicating the one or two sensing modules with the highest score that identified the radial artery location.

Figs. 3A-3B are block diagrams of non-limiting examples of embodiments of the system according to an aspect of the present disclosure. Fig. 3A exemplify a system 301 that includes a device 300 having a contact surface 302 having a plurality of contact surface zones 303. The contact zones 103 are configured to be brought into contact with said curved skin area so as to allow a change of the contact surface 302 shape to conform at least partially to the shape of the curved skin area.

Each sensing module 304i is in a fixed association with one or more corresponding contact surface zones 303, namely each member of the sensing module 304i is in a fixed association with a contact surface zone 303. The sensing module 304i includes an illuminator 306i having an illumination optical axis and configured to illuminate and direct light IL (li, Ii) to a respective unique region URi associated only with said module. The unique region URi is spaced from the contact surface zone so that, when the contact surface zone 303 is in contact with the skin area, the unique region is disposed further from the contact surface zone than the skin area, namely at a more distal location along the respective illumination axis than the skin area of the subject, e.g. a location under the skin of the subject. The sensing module further includes a detector 308i having a detector optical axis forming an angle with the illumination optical axis and configured to detect illumination response IR (lϊ, Ii) of light returned from said unique region URi and to generate based thereon, when the contact surface zone is in contact with the skin area, a signal suitable to be compared with signals obtained from the detectors of the other sensing modules based on the detection of light returned from their associated unique regions, so as to obtain said optical data.

The system further includes a processing circuitry 320 configured for receiving the optical data ODi derived from each detector 308i and to extract physiological data PD therefrom to be communicated or displayed to a user US.

The processing circuitry may utilize the optical data of all the detectors or the optical data of one or more selected detectors to extract the physiological data. The processing circuitry may be configured for scoring the optical data of each detector and select one or more optical data sets of the highest scored detectors and determine the physiological data of the subject based thereon.

The physiological parameter of the subject may be one or more of blood pressure, SPO₂, heart rate, respiration rate and/or the accurate position of an artery, such as the radial artery of the subject. The system may indicate the position of the radial artery either by signaling a location over the wrist of the subject or by indicating the one or two sensing modules with the highest score that identified the radial artery location.

As exemplified in Fig. 3B, the system may include a signaling device 322 for outputting a location signal LS signaling the location of the radial artery.

In some embodiments, the device 300 may further include a transmitting unit 318 for transmitting the optical data ODito the processing circuitry 320.

The system may include additional sensors for sensing additional physiological parameters and/or increasing the accuracy of the collected optical data. For example, the system 301 may include a displacement sensor 324 for detecting movements of the device to identify artifact signals AS detected in the optical data ODi and neglect them in the processing. Furthermore, the processing of the optical data ODi may be carried out with respect to other parameters collected by other sensors. For example, an ECG sensor 326 may sense ECG signals ECGS of the subject together with the device 300 and the processing circuitry 320 is configured for processing the ODi and the ECG signals ECGS to determine the physiological data PD. The processing may include extracting the pulse transit time (PTT) of the subject from the ECG signals ECGS and the respective optical data ODi and based thereon determine the physiological data PD.

Reference is made to Figs. 5A-5C, which are illustrations of different views of a non-limiting example of an embodiment of the arm wrist arrangement according to an aspect of the present disclosure. Fig. 5A shows a perspective view of an arm wrist arrangement 500 that includes an engagement unit 502 that has a sensor 504 configured to sense biological parameters from a skin of a subject. The sensor 504 has a contact surface 506 that constitute the top of the engagement unit 502. The contact surface 504 has a transparent portion 506A for allowing optical measurement of the sensor 504 and a non-transparent portion 506B, which can best be seen in Fig. 5B, which is a top view of the arm wrist arrangement. The arm wrist arrangement 500 further includes a compressible member 508 that surrounds the engagement unit 502 from all its lateral directions. In other words, the compressible member 508 is formed with a gap/opening 510 that is configured to accommodate the engagement unit 502. The compressible member may be formed from various materials that are configured to be compressed and deformed in response to application of pressure and return to their original form when the pressure on them is removed. The compressible member 508 is symmetric such that each portion has its corresponding similar portion on the other side of the engagement unit 502. For example, portion 508A has its corresponding portion 508A' and portion 508B has its corresponding portion 508B'.

The compressible member 508 is formed on a support 512 with a matching shape that has a gap in its center where the engagement unit 502 is disposed. A flexible member 514 spans the gap 510 and links the engagement unit 502 and the support 512 to allow the movement of the contact surface 506 at least along a vertical axis Z, which can be seen in Fig. 5C.

The contact surface 506 spans a contact surface plane, exhibited in Fig. 5C by the line P. As can be appreciated, the portions 508A and 508A' of the compressible member 508 are extending above the contact surface plane P, namely extending to the facing out FO side of plane P, such that when a skin surface contact the contact surface 506, the pressure is distributed between the contact surface 506 and the compressible member 508. In this manner, inconvenience by the pressure related to the measurement of the sensor 504 by the contact surface 506 on the skin is reduced. The majority portion 508C, in terms of volume or amount of compressible, is disposed at the facing in FI side of the contact surface plane P. However, the greater the pressure on the contact surface 506, the greater its movement in the direction of arrow A, and as result of this movement, portions 508A and 508A' increase, e.g. by their volume or by their amount of compressible material.

The arm wrist arrangement 500 may be a link in a wristband (not shown), e.g. a wristband of a watch. The arm wrist arrangement includes through holes 516 that are configured to be used for linking with other links of the wristband. The wristband is designed to include the arm wrist arrangement 500 in a position such that when the wristband is worn on a subject's wrist, the arm wrist arrangement 500 is positioned over or in the vicinity of the radial artery. Reference is now made to Figs. 6A-6C, which are different views of non-limiting examples of an embodiment of a device for measuring a physiological parameter of a subject that is configured for identifying a desired location for carrying out the measurement from a skin portion of the subject.

The device 650 includes a first measuring unit 652 that has a contact surface 654 that is disposed at a measurement face 656 of the device 650 and is configured for contacting a skin of a subject upon measurement. The contact surface 654 is configured to move at least along an axis Y, as can be best seen in Fig. 6B, that is generally normal to the measurement face 656. The displacement of the contact surface 652 due to pressure that is applied thereon by the skin of the subject is measured, which is indicative of a physiological parameter of the subject, such as blood pressure, heart rate, respiration rate, etc. The device 650 is configured to be placed over an artery, typically over the radial artery on the wrist for measuring the movement of the skin due to expansion and reduction of the radial artery. The fine adjustment for carrying out the measurement at an exact location over the radial artery is of a great importance for obtaining a meaningful measurement with high signal to noise ratio. Therefore, the device 650 includes second measuring units 658A, 658B, 658C and 658D that are configured to emit light towards the skin of the subject and detect the reflection therefrom. For example, each second measuring unit may include a configuration of a light emitter and light detector similar to that of Fig. 4C. It is to be noted that any angle can be formed between the optical axes of the light emitter and the light detector and they also can be parallel. The intensity of the detected reflection is indicative of the relative position of the respective second measuring unit from the accurate position of the radial artery. Since the location of each second measuring unit with respect to the contact surface 654 of the first measuring unit 652 is known, the relative position of the contact surface 654 from the radial artery, the desired measurement location, is determined. The device 650 is configured to receive a wristband through ports 660A and 660B which allow the sliding of the device 650 along different portion of the skin of the subject when the device is worn. The data obtained from the second measuring units 658 A, 658B, 658C and 658D is processed to determine the relative position of the contact surface 654 with respect to the desired measurement position and a signaling unit (not shown) is configured to exhibit a signal to the subject that indicates whether it is required to slide the device along the wrist, to which direction and what extent. The device includes a housing 662 that encloses portions of the first and second measuring units, and the contact surface 654 is configured to move with respect to the housing 662.

As can be appreciated from Fig. 6C, the second measuring units 658A, 658B, 658C and 658D are arranged along axes Xi, X2, X3 and X4 respectively. Each measuring unit along a respective axis generates measured data indicative of the relative position of the artery with respect to itself. The data from two or more measuring units along an axis provides an indication of the relative position of the contact surface 654 with respect to the artery along the respective axis. According to said indication, the device is repositioned along the respective axis such that the contact surface 654 is placed over the artery.

In Fig. 5-8, like elements of different figures were given similar reference numerals shifted by the number of hundreds corresponding to the number of the figures. For example, element 752 in Fig. 7 serves the same function as element 652 in Figs. 6A- 6C.

Fig. 7 is a perspective view of non-limiting example of an embodiment of a wristwatch that includes the device of the present disclosure. The device 750 is in sliding association with the wristband 762 of the watch 764 and the displacement sensor 752 is received within an opening 766 in the wristband 762 that confines its movement between a first end of the opening 768 and a second end of the opening 770. The second measuring units 758 are surrounding the displacement sensor and configured to emit light towards the skin of the wrist of the subject when the watch is worn thereon, and detect the reflection of the emitted light from the skin. Each of the second measuring units 758 provides a measurement indicative of the intensity of the reflection of emitted light, e.g. infra-red light, from the skin of the subject and based thereof, an indication is exhibited to the user indicating to where, and to what extent, the displacement sensor needs to be moved in order to be in a desired measurement location, e.g. over the radial artery.

Figs. 8A-8B are perspective views of a non-limiting example of an embodiment of the device, in which it includes a plurality of first measuring units. Fig. 8A shows a device 850 that includes three first measuring units 852 in the form of movement/displacement sensors that are configured to measure the movement of the skin of the subject when it is brought into contact therewith. The displacement sensors 852 are disposed along an axis U of the device 850 such that they measure from several portions of the skin subject when the device is brought into contact with the skin. Each of the displacement sensors 852 may be differently oriented from the others such that each has a different main measuring direction Di, D2 and D3, so as to match the contour of the wrist of the subject. Second measuring units 858, e.g. IR-based PPG sensors, are disposed around the displacement sensors 852 and configured to obtain data indicative of the relative position of each of the displacement sensors with respect to the desired measuring position. The second measuring units 858 are non-symmetrically disposed on both sides of the vector of the displacement sensors 852, namely second measuring units at one side of the displacement sensors are disposed at different positions along axis U than the second measuring units at the other side of the displacement sensors. In Fig. 4B, the device 850 is associated with a wristwatch 864, either in a fixed manner or in a slidingly manner along the wristband 862 of the watch 864.

Claims

CLAIMS:

1. A device for measuring a physiological parameter of a subject, the device having a measurement face and comprising: a first measuring unit having a contact surface at said measuring face and configured for contacting the subject's skin for measuring physiological data indicative of the physiological parameter, wherein the measurement is performed either (i) via the contact surface, or (ii) in response to movement of the contact surface in response to contact with the skin of the subject; at least one second measuring unit at said measurement face, and comprises an optical unit that is configured for emitting light toward the skin of the subject, detect the light response therefrom and generate light data based thereon; a control unit configured for receiving and processing said light data and generate position data indicative of a position of the contact surface with respect to a desired measurement position.

2. The device of embodiment 1, comprising a signaling unit configured to receive said position data and to exhibit a signal indicative of the position of the contact surface with respect to the desired measurement position.

3. The device of embodiment 1 or 2, wherein the first measuring unit comprises a displacement sensor configured to sense the displacement of the contact surface along at least an axis normal to the measurement face.

4. The device of any one of embodiments 1-3, wherein the optical unit comprises a light emitter configured to emit light of a wavelength range that has a relatively high light response from the desired measurement position, and a light detector configured to detect the light response of said light from the desired measurement position.

5. The device of embodiment 4, wherein said desired measurement position is above the radial artery of the subject and said wavelength range is in the IR band.

6. The device of embodiment 5, wherein said wavelength range is 700-950nm.

7. The device of any one of embodiments 1-6, wherein a distance between said optical unit and the contact surface at least does not exceed at least one of the following: - a distance between the second measuring unit and a peripheral boundary of the measurement face; or maximal dimension of the contact surface along the measurement face.

8. The device of any one of embodiments 1-7, wherein said light data has a predetermined reference profile associated with different distances, at which said at least one second measuring unit can be disposed relative to the desired measurement position, and said control unit is configured to generate the position data based on comparison of the light data with the reference profile.

9. The device of any one of embodiments 1-8, comprising at least two second measuring units.

10. The device of embodiment 9, wherein the at least two second measuring units are disposed at different distances from the contact surface.

11. The device of embodiment 9 or 10, wherein two or more of said second measuring units are disposed along a first linear axis, defining a first linear group.

12. The device of claim 11, wherein two or more of said second measuring units are disposed along a second linear axis, defining a second linear group, wherein the first and second linear axis are defined on the same plane and are angled with respect to one another.

13. The device of claim 12, wherein the first and the second linear axis are normal to one another on said plane.

14. The device of any one of embodiments 9-13, wherein at least two of said second measuring units are disposed on one side of the contact surface.

15. The device of any one of embodiments 9-14, wherein at least two of said second measuring units are disposed on two lateral opposite sides of the contact surface.

16. The device of any one of embodiments 9-15, wherein the control unit is configured to receive corresponding light data from each of the second measuring units and generate the position data based thereon.

17. The device of any one of embodiments 9-16, comprising a wristband port configured to receive a wristband wearable on a wrist of the subject and to engage the wristband so as to allow the device to be slidingly moved therealong.

18. The device of embodiment 17, wherein two or more of said second measuring units are disposed side by side along one linear axis or along each of at least two linear axes, and wherein the linear axis, or at least one of the at least two linear axes, is oriented with respect to a direction, in which the device is slidingly movable along the wristband.

19. The device of embodiment 17 or 18, wherein the device comprising a locking mechanism configured for locking the device at a position along the wristband.

20. A system comprising an array of two or more devices of any one of embodiments 1-20; and a controller configured to receive the position data and the physiological data of each of the two or more devices and determine the physiological parameter based thereon.

21. A system comprising an array of two or more devices of any one of embodiments 1-20; and a controller configured to receive the position data and the physiological data of each of the two or more devices and determine the physiological parameter based thereon, wherein the two or more devices are integral with a wristband of a wristwatch.

22. The system of embodiment 20 or 21, wherein the controller is embedded within a housing of the wristwatch.

23. The system of any one of embodiments 20-22, wherein the controller is configured to calculate weighting factor for each position data, based on its proximity to the desired measurement location, and to apply the calculated weighing factors on each of the respective physiological data to determine the physiological parameter.

24. The system of any one of embodiments 20-23, wherein the controller is configured to identify the most proximate device to the desired measurement location and to determine the physiological parameter based on the physiological data retrieved from the respective device.