Wrist sensor for measuring physiological parameter

Abstract

The present disclosure provides a device for measuring a physiological parameter of a subject. The device comprises a pliable pad associated with sensors, e.g. applied on a surface thereof. The sensors are configured for measuring signals that are indicative of pressure applied on the pliable pad or on the sensors. The pliable pad is designed so as to be capable of bending to conform with the shape of the wrist of the subject it engages with. By conforming with the shape of the wrist, the pliable pad increases the sensitivity of the measurement by the sensors. The sensors are intended to be positioned on the wrist of the subject so as to be able to sense the minute deformations of the skin due to change of blood flow in the blood vessels below the skin, e.g. the radial artery. For fitting to the wrist, the pliable pad is coupled to a coupling member that is configured to allow fitting of the device to the wrist of the subject and fixing the pliable pad at a desired position for obtaining the measurements.

Description

[0001] WRIST SENSOR FOR MEASURING PHYSIOLOGICAL PARAMETER

[0002] TECHNOLOGICAL FIELD

[0003] This disclosure concerns a device, fitting over the wrist of a wearer for measuring physiological parameters.

[0004] BACKGROUND ART

[0005] References considered to be relevant as background to the presently disclosed subject matter are listed below:

[0006] - EP 3923089A1

[0007] - US 8,870,448B2

[0008] - WO 2016 / 125034A1

[0009] Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

[0010] BACKGROUND

[0011] EP 3923089A1 discloses a watch strap that is formed from a flexible material. The watch strap includes an electronics module that is embedded within the flexible material. The electronics module includes a sensor for acquiring sensor data that may include pulse rate and blood oxygenation level.

[0012] US 8,870,448B2 discloses a watch strap having a comfort pad with a longitudinal opening that is arranged on the inner surface of the strap towards one of the ends of the strap.

[0013] WO 2016 / 125034A1 discloses a smart watchband with integrated electronics that can be attached to any mechanical or digital wristwatch. The watchband has a flexible circuit board and a variety of sensors including an embedded heart rate sensor, body temperature sensor, ambient temperature sensor and some other elements. The watchband is powered by a rechargeable battery. GENERAL DESCRIPTION

[0014] The present disclosure provides a device for measuring a physiological parameter of a subject. The device comprises a pliable pad associated with sensors, e.g. applied on a surface thereof. The sensors are configured for measuring signals that are indicative of pressure applied on the pliable pad or on the sensors. The pliable pad is designed so as to be capable of bending to conform with the shape of the wrist of the subject it engages with. By conforming with the shape of the wrist, the pliable pad increases the sensitivity of the measurement by the sensors. The sensors are intended to be positioned on the wrist of the subject so as to be able to sense the minute deformations of the skin due to change of blood flow in the blood vessels below the skin, e.g. the radial artery. For fitting to the wrist, the pliable pad is coupled to a coupling member that is configured to allow fitting of the device to the wrist of the subject and fixing the pliable pad at a desired position for obtaining the measurements.

[0015] By one aspect, the sensor device makes use of a graphene layer that is disposed on or comprised in a carrier element, e.g. a base or a substrate that can carry the graphene. By another aspect the sensor is a strain gauge disposed on or comprised in a carrier element. The graphene layer and the strain gauge may be collectively referred to as "planar sensor element" .

[0016] The carrier has a contact surface for contacting a skin portion of a subject that is deformed in consequence of skin deformations as a result of physiological properties, for example owing to changes of blood flow or blood pressure within blood vessels below the skin portion. Namely, deformations of the skin portion , which can be minor changes resulting from blood volume changes in arteries such as the radial artery or in small blood vessels such as arterioles within a tissue of the wrist of the subject, cause respective deformations of said contact surface that is picked up by the sensor. The pressure applied on the contact surface resulting in a change of one or more electrical parameters of the planar sensor element, e.g. the graphene layers, such as its impedance, that is measurable. By measuring the change of the one or more electrical parameters, the pressure variation exerted on the contact surface over time can be determined, which is indicative of the physiological parameter.

[0017] The physiological parameter, measurable by this and other embodiments of this disclosure may be heartbeat, heartbeat-related parameter, or respiration rate, all of which give rise to pressure waves that travel in blood vessels and give rise to local deformations of the skin. The signal that is obtained by the sensor device of this disclosure may be a waveform signal resulting from such changes on said skin portion. By analyzing the waveform signal, a variety of physiological parameters can be determined and also movements of muscles or tendons that can be regarded as artifact movements that are required to be eliminated during measurements of physiological parameters by the sensor of the present disclosure or other sensors associated therewith, e.g. sensors that share the same contact surface. In addition to physiological parameters that are reflected in pressure waves travelling along blood vessels, there may also be others that are reflected in some deformation of the skin, such as deformations that are caused by muscle activity.

[0018] Therefore, the first aspect of the present disclosure provides a sensor device for measuring a physiological parameter from a skin portion of a subject. The sensor device comprising a carrier base or a substrate. The carrier should be understood as a material that can be applied with or include therein a layer of graphene. The carrier defines a contact surface for contacting directly or indirectly said skin portion. An indirect contact with the skin portion should be understood as a contact with another element that is in contact with the skin portion and change of pressure by the skin portion on said element results in a correspondence change of pressure on said contact surface. For example, the substrate may be in association with a pliable member that is intended for contact with the skin.

[0019] The sensor device further comprises a patterned layer of graphene disposed on or embedded in said carrier, such that one or both of (i) pressure applied on said layer, and (ii) deformation of said layer, results in a change of at least one electrical parameter of said layer. The layer is typically a thin layer and the carrier may be also relatively thin such that the whole sensor device is thin. The change of the at least one electrical parameter of said layer is indicative of said physiological parameter or a change thereof. The change is readable by an electronic circuitry, i.e. a reader that is capable of transmitting data representative of the change of the at least one electrical parameter of said layer to a processing unit that can determine the physiological parameter therefrom.

[0020] It is to be noted that any combination of the embodiments described herein may be applicable to any aspect of this disclosure. In other words, any aspect of the present disclosure can be defined by any combination of the described embodiments.

[0021] In some embodiments of the sensor device, the physiological parameter is one causing skin deformations, which may be minute deformations including such resulting from minute muscle twitching or from a pressure wave travelling in the underlying vasculature.

[0022] In some embodiments of the sensor device, the physiological parameter is a cardiovascular parameter.

[0023] In some embodiments of the sensor device, said physiological parameter is a heartbeat-induced pressure change in the vasculature in said skin portion.

[0024] In some embodiments of the sensor device said carrier is a planar substrate.

[0025] In some embodiments of the sensor device said carrier is pliable, flexible or reversibly deformable.

[0026] In some embodiments of the sensor device, said carrier comprises poly- oxydiphenylene-pyromellitimide, also known as Kapton.

[0027] In some embodiments of the sensor device, said patterned layer of graphene is formed on said carrier by laser etching. The laser etching can be performed as described in US 11,437,620, which is hereby incorporated by reference.

[0028] In some embodiments of the sensor device, said patterned layer defines one or more continuous paths, the electrical parameter being determined between two space- apart points in such one or more paths. The path can be a serpentine path, tortious path or any other suitable patterns.

[0029] In some embodiments, the sensor device further comprises an electronic circuitry coupled to said layer and configured for reading the at least one electrical parameter of said layer, and for outputting a signal corresponding thereto or corresponding to a change in said parameter, which may be data representative of the signal or change and transmitted either to a remote device, e.g. a smart phone or a computer, or to a cloud server.

[0030] In some embodiments of the sensor device, said electronic circuitry comprises a processor configured for processing the read at least one electrical parameter for determining said physiological parameter. The outputting of a signal corresponding thereto or corresponding to a change in said parameter comprises outputting data corresponding to or representative of said physiological parameter.

[0031] In some embodiments of the sensor device, the at least one electrical parameter is selected from any one of: resistance, conductance, capacitance, electrical potential, impedance, or any combination thereof. In some embodiments, the sensor device further comprises two or more of said carriers. Namely, there are two space-apart carriers with graphene layers.

[0032] In some embodiments, the sensor device further comprises a power source for providing power to the electronic circuitry.

[0033] In some embodiments, the sensor device is configured for connection to an external power source to electrify the electronic circuitry.

[0034] In some embodiments, the sensor device further comprises a wireless transmitting utility configured for transmitting an output signal to another device.

[0035] In some embodiments of the sensor device, said wireless transmitting utility is a low-power Bluetooth transceiver.

[0036] In some embodiments of the sensor device, the wireless transmitting utility is configured for transmitting said data signal to one or more of a smart watch, a mobile communication device and a computer.

[0037] In some embodiments, the sensor device further comprises a wired transmitting utility configured for wired transmission of said data signal to an external device (e.g. smart watch).

[0038] In some embodiments, the sensor device is used for measuring artifact movements of the measures skin portion. The measured artifact movements are used to indicate when the measurement of a physiological parameter, either measured by the sensor device or a sensor associated therewith, is valid or not. Namely, by identifying artifacts, invalid measurements can be neglected, and the measurement of the physiological parameter is not based on such neglected measurements.

[0039] In some embodiments, the sensor device is embedded in a ring or other wearable for continuous measurement of any one of heart rate, pulse rate, respiration rate and blood pressure.

[0040] Yet another aspect of the present disclosure provides a method for measuring a physiological parameter from a skin portion of a subject. The method comprises contacting, directly or indirectly, a contact surface of a sensor device with said skin portion. The sensor device comprises: (1) a carrier, a base or a carrier base defining said contact surface, and (2) a patterned layer of graphene disposed on or embedded in said carrier, such that one or both of (i) pressure applied on said layer, and (ii) deformation of said layer, results in a change of at least one electrical parameter of said layer. The method further comprises measuring said change of at least one electrical parameter and generating sensed data representative thereof; and outputting said sensed data for analysis to determine said physiological parameter.

[0041] In some embodiments, the method further comprises analyzing said change of at least one electrical parameter of said layer for determining said physiological parameter.

[0042] In some embodiments of the method, said sensor device is any one of the above - described embodiments of the sensor device or any combination thereof.

[0043] In yet another aspect, the present disclosure provides a device for measuring physiological parameters, such as blood pressure. The device of this disclosure makes use of a pad or small cushion (to be referred to herein as "pad'), that is fitted or that is configured to be fitted on an inner, wrist-facing side of a wristband, which may be an independent wristband or one serving as a watchband. The pad has a pliable wrist-bearing surface that is placed against the wrist over a portion of the wrist that may comprise one or both of the radial or the ulnar artery. The physiological parameters that are measured are such that give rise to small surface deformations of portions of the wrist on which the wrist-facing surface is placed and these, typically, but not exclusively, arising from pressure changes as a result of blood flow within the arteries or blood pressure pulses. Such deformations cause deformations of the wrist-facing surface and may give rise to small pressure changes within the pad. Such deformations of the wrist-facing surface or pressure changes within the pad are picked up by sensors and converted into signals that can then be processed and translated into a measure of a physiological parameter.

[0044] These pressure changes are measured by a gauge that is responsive to the change of pressure and issues a signal corresponding thereto.

[0045] Provided by embodiments of this disclosure is a device for measuring a physiological parameter that comprises a pliable pad and one or more sensors disposed within the pad. The pad is fitted or is configured for fitting on a wrist-facing side of a wristband and has a wrist-bearing surface that is conformed or is comfortable to the topology of the wrist. When the device is intended to measure physiological parameters such as blood pressure, pule rate and others, the pad is typically of a length such that when placed on the wrist it will cover an area of the wrist surface that includes one or both of the radial and ulnar arteries without the need for searching these arteries and exact positioning. In other words, once a wristband (e.g. a watchband) with the device is fitted onto a wrist the pad having said length would overlay a portion of the wrist surface that includes these arteries without the need for fine positioning.

[0046] The one or more sensors are disposed within or associated with said pad and are intended for sensing one or both of (i) change of pressure within the pad, and (ii) deformation of the wrist-bearing surface, and for issuing an output signal corresponding thereto indicative of said physiological parameter.

[0047] By an embodiment, the device comprises a base that is attached to or is fitted over an inner, wrist-facing face of a wristband that extends along a wristband axis (which when worn extends circumferentially around the wrist) or is configured for such attachment or fitting. The pliable pad may be attached or attachable to the base. The device has typically, albeit not exclusively, two edges that extend along edges of the wrist band and has a width such that it is confined between the wristband’s side edges.

[0048] By another embodiment the pad is integrally formed on an inner side of said wrist band.

[0049] The device typically comprises an electronic utility for receiving and processing said output signal and for emitting a data signal based thereon. It should be noted that the electronic utility may also, in some cases, be external to the device connectable to the sensor by wired or wireless communication (e.g. through low power Bluetooth).

[0050] By specific, albeit not exclusive, embodiments of the device the measured physiological parameter is blood pressure.

[0051] The pad, by some embodiments is a fluid-filled enclosure having a pliable wristbearing surface. The fluid may, for example, be a gas, liquid, a gel or a thick oily substance such as grease. It should, however, be noted that pad by some embodiments may not be an enclosure and have a uniform consistency.

[0052] By some embodiments, the fluid-filled enclosure is filled with gas, e.g. air. The gas may be pressurized to a certain pressure.

[0053] By some embodiments, the fluid-filled enclosure is filled with liquid, e.g. water, or water-based solution.

[0054] By some embodiments, the fluid-filled enclosure is filled with gel.

[0055] By some embodiments, the fluid filled enclosure is filled with a non-drying solution or a non-drying oil.

[0056] By some embodiments, the fluid filled enclosure is filled with a non-volatile solution. The terms “non-drying solution” and “non-volatile solution” refer to materials that resist evaporation or hardening when exposed to air. Non-drying solutions may include one of the following: greases (thick, lubricating substances), oils (liquid fats that don't easily evaporate), and resins (natural or synthetic sticky substances that may not harden quickly). These materials are often characterized by their stable, long-lasting consistency and their resistance to air drying or evaporation under normal conditions. The advantage of using such non-drying solutions is due to the fact that the internal volume of the pliable pad may be not entirely fluidically sealed for exchange of small molecules, such as gas molecules or water molecules. Therefore, aqueous-based solutions may dry overtime and lose their pliable properties, which will affect the efficacy of the device.

[0057] By some embodiments, the fluid filled enclosure is filled with grease.

[0058] The pad may be so configured that deformation of central portion of the wristbearing surface will not substantially deform edge portions thereof. This may be achieved, for example, by attachment or tight association of the edge portion to a rigid edge element of the base, by a rigid side wall of the pad, by other structural elements, by different blends of two or more substances that are used to form the wrist-bearing surface, by varying wall thickness of the wall of the enclosure that defines the wrist-bearing surface, etc. The pliability of the wrist-bearing surface may, thus, vary between a central portion thereof towards its periphery.

[0059] The pad may be elongated and trace a circumferential portion of the wrist, along the wristband axis.

[0060] The device may have an overall arcuated shape to trace approximate contours of the wrist.

[0061] One example of a sensor is one that comprises a pliable element that changes its impedance upon its deformation. Said pliable element is electronically coupled to an electronic circuitry for measuring the impedance and / or changes in impedance and issuing an output signal corresponding thereto. Said pliable element is fitted within said pad or is associated with the wrist-bearing surface such that one or both of (i) change of pressure of the fluid and (ii) deformation of the wrist fitting surface, deforms said pliable device. Said pliable element may be fitted on the wrist-bearing surface or may be embedded within the pad, for example, just below the surface. One example of such a pliable element is one that comprises a strain gauge or graphene. While in some embodiments that device comprises one such pliable element, in other embodiments the device may comprise two or more such elements. For example: two or more in a linear arrangement along the pad axis; two or more that are parallel to one another with respect to the pad axis; a 2D array of such elements, for example two parallel pairs arranged in series along the pad axis; etc.

[0062] Where there are two or more such elements that are disposed in a parallel arrangement, a first of a parallel pair is overlying a portion of the wrist that is more proximal, with respect to the direction of arterial blood flow, than a second of the pair. Such a device may be used, for example, for measuring a pulse wave velocity, by measuring the time of arrival of the pulse wave in two points with a known distance between them. Namely a pulse wave reaches and is measured first by one element and then, after a short delay, reaches and is measured by the other, providing a measure of the speed of propagation that may also be an indication of blood pressure.

[0063] By some other embodiment the sensor comprises a piezoelectric element. The piezo electric element may be disposed on or against a flexible surface associated with said pad and that can, this, undergo some deformations upon one or both of (i) pressure changes within the pad and (ii) deformation of the wrist fitting surface.

[0064] By some embodiments the flexible pad is divided into two or more separate compartments, parallel to one another, and wherein each compartment comprises separate one or more of said sensors for measuring one or both of (i) change of pressure within the compartment, and (ii) deformation of the wrist fitting surface of said compartment, and for issuing an output signal corresponding thereto. Such separate compartments may be arranged in parallel along the pad axis, configuring them for measuring pulse velocity in a manner analogous to that described above.

[0065] The device by some embodiments may comprise a power source, that may be regular (fixed) or a chargeable battery (the charging of which may be by wired or wireless means. It is also possible, be certain other embodiments, for the device to be configured for connection to an external power source (for example, that of an electric or smart watch).

[0066] The device by some embodiments may comprise a wireless transmitting utility (e.g. a transceiver) configured for transmitting said data signal to another device, which may be one or more of a smart watch, a mobile communication device and a computer. The wireless transmitting utility may include a low -power Bluetooth transceiver. Such a wireless connection may also serve for the purpose of control, configuration or software update. As can be appreciated, rather than wireless, the connection to a smart watch, for example, may also be wired.

[0067] In some embodiments of the device, said one or more sensors are printed on the pliable wrist-bearing surface. By printing the sensors on the pliable wrist-bearing surface, the sensor can be flexible and conform with the bending of the pliable pad that resulted from the shape of the wrist or application of pressure on the pliable pad. Furthermore, the measurement of the sensor can be more accurate as it in direct or almost direct contact with the skin portion that applies a pressure on the pliable pad. For example, one or more strain gauge sensors can be printed on the pliable wrist-bearing surface.

[0068] In some embodiments of the device, the printed one or more sensors are covered by a protective cover. The protective cover may be a thin film of the pliable pad or other protective cover material that ensures that the sensor is not damaged by the pressure applied on the pliable pad.

[0069] In some embodiments of the device, the protective cover is made of the same material as the pliable pad. Namely, a thin film of the pliable pad covers the one or more printed sensors.

[0070] In some embodiments of the device, said one or more sensors comprise at least one light source, typically a light-emitting-diode (LED) (although other light sources may be envisaged) and at least one light detector, typically a photodiode (PD). The at least one light source is positioned so as to illuminate an internal volume of the pliable pad. The at least one PD is positioned so as to detect the illumination response to the illumination within the internal volume of the pliable pad. The output signal is, thus, indicative of variation of the illumination response due to a pressure applied on the pliable pad. The illumination response results from the interaction of the illuminating light within the internal volume of the pliable pad, for example scattering or absorption by the medium contained in the internal volume and / or by the surrounding walls, or fluorescence response of the medium.

[0071] It is to be noted that for the realization of the one or more sensors based on light source and light detector, the internal volume of the pliable pad is filled with a transparent or semi-transparent material for the illumination illuminated from the at least one light source. The material can be either gas, e.g. air, liquid or gel that is able to transmit the illumination of the light source. In some embodiments of the device, the pliable pad defines edges confining its internal volume. For example, in the case when the pliable pad is rectangular, its four walls define the edges.

[0072] In some embodiments of the device, the at least one light source comprises at least one light source and the at least one detector comprises at least one light detector.

[0073] In some embodiments of the device, the at least one lights source and the at least one light detector are disposed on edges of the pliable pad, e.g., adjacent one another.

[0074] In some embodiments of the device, the at least one light source and the at least one light detector are disposed on the same side of the internal volume of the pliable pad.

[0075] In some embodiments of the device, the optical field of view of the light detector does not include the light source. In other words, the sensing surface of light detector is outside the illuminated image region of the light source (the field of view of the light source). Therefore, the light detector detects only illumination that interacted with the internal volume of the pliable pad or with one of its edges or surfaces, e.g. scattered light or fluorescence.

[0076] In some embodiments of the device, the at least one light source and the at least one light detector are disposed on opposite edges of the pliable pad, Namely, the at least one light source is disposed on a first edge of the pliable pad that is opposite to a second edge of the pliable pad, on which the at least one light detector is disposed. Therefore, light emitted from the light source is directed towards the light detector and pressure on the pliable pad causes interference in the light transmission, which results in variation of the illumination response.

[0077] In some embodiments of the device, the at least one light source and the at least one light detector are disposed on opposite sides of the internal volume of the pliable pad. It is to be noted that the light source and the detector may be disposed at a position different than the edges of the pliable pad. Namely, the light source is positioned on a first half of the pliable pad and the light detector is positioned on a second half of the pliable pad, opposite the first half.

[0078] In some embodiments of the device, the optical field of view of the light detector includes the illuminated image region of the light source, namely the light detector is found within the region that receives direct illumination from the light source.

[0079] In some embodiments of the device, the pliable pad or at least part thereof is covered with an optical reflecting material causing a reflection of the illumination of the light source. Therefore, the illumination from the light source is repeatedly internally reflected and, hence, maintained within the internal volume of the pliable pad.

[0080] In some embodiments of the device, the at least one light source and the at least one light detector are positioned such that one of them is disposed on the wrist-bearing surface or in proximity thereto and the other is disposed on an opposite surface to the wrist-bearing surface or in proximity thereto.

[0081] In some embodiments of the device, the at least one light source and the at least one light detector are positioned such that their optical axes have at least a component that is normal to the plane spanned by the wrist-bearing surface.

[0082] In some embodiments of the device, the at least one light source and the at least one light detector are positioned such that their optical axes are normal to the plane spanned by the wrist-bearing surface. This allows to ensure that deformations of the pliable wrist-bearing surface in a result of pressure applied thereon will cause direct change of the light path. For example, if the light source and the light detector are facing one another, the light path is shortened under pressure and a variation of detected intensity of light is observed.

[0083] In some embodiments, the device further comprises a light blocking element that is disposed within the pliable pad, namely in its internal volume. The light blocking element is positioned such that it proportionally blocks an amount of light emitted from the light source from reaching to the light detector. In other words, the extent of the pressure applied on the wrist-bearing surface results in a proportional blocking of light emitted from the light source from reaching the light detector due to movement of the light blocking element in response to the applied pressure. For example, the higher the pressure applied, the more light reaching the detector. In another example, the higher the pressure applied, the less light reaching the detector. The detector can be positioned anywhere along one of the light paths from the light source to the light detector.

[0084] In some embodiments of the device, the optical axis of the light source is in the optical field of view of the light detector. The light blocking element is disposed at a position along the optical axis.

[0085] Ins some embodiments of the device, the at least one light source is positioned partially or entirely outside the pliable pad. The light source is positioned such that it is illuminating the internal volume of the pliable pad. In some embodiments of the device, the at least one light source is positioned outside the pliable pad and its internal volume.

[0086] In some embodiments of the device, the at least one light detector is positioned partially or entirely outside the pliable pad. The light detector is positioned such that it is illuminating the internal volume of the pliable pad.

[0087] In some embodiments of the device, the at least one light detector is positioned outside the pliable pad and its internal volume.

[0088] In some embodiments of the device, said one or more sensors are strain gauge sensors.

[0089] In some embodiments of the device, said one or more sensors are constituted by a patterned graphene layer.

[0090] In some embodiments of the device, said graphene layer defines a path. The device comprises a reader that is configured to measure an electric parameter between two points along the path over time. The pressure applied on the pliable pad over time can be determined from the electrical parameter variation over time, which is indicative of the physiological parameter. The electrical parameter can be resistance, impedance, voltage, current or any combination thereof.

[0091] In some embodiments of the device, said pliable element comprises the sensor device of any one of the above-described embodiments of the sensor device or any combination thereof.

[0092] In some embodiments of the device, said one or more sensors are one or more of said above-described embodiments of the sensor device sensor device or any combination thereof.

[0093] In some embodiments of the device, the pliable pad and the one or more sensors constitute together a sensor device, wherein the sensor device is any one of the abovedescribed embodiments of the sensor device sensor device or any combination thereof.

[0094] Yet another aspect of the present disclosure provides a device for measuring a physiological parameter. The device comprises a pliable pad having a pliable or flexible wrist-bearing surface and configured for placing against a portion of the wrist. The device further comprises one or more sensors disposed on, within or associated with said pliable pad, the association should be understood as either a direct coupling or attachment to the pad or an indirect attachment via an additional element, for sensing at least one of (i) change of pressure on the pad, (ii) deformation of the wrist-bearing surface, (iii) change of pressure applied on said one or more sensors or, (iv) deformation of said one or more sensors, and for issuing an output signal corresponding thereto indicative of said physiological parameter or a change thereof.

[0095] In some embodiments of the device, the one or more sensors comprise one or more strain gauge sensors.

[0096] In some embodiments of the device, the one or more sensors comprise one or more light-based sensing arrangements, each of which comprises: (1) a light source member configured to emit light at a defined wavelength. It is to be noted that there may be more than one light source member, each of the light source members may emit light at a different wavelength; (2) a light detector member configured to detect illumination response to illumination at said defined wavelength. The illumination response should be understood as reflection, scattering, fluorescence or any other response of the illumination that may be detected by the light detector.

[0097] In some embodiments of the device, said one or more light-based sensing arrangements are PPG sensors.

[0098] In some embodiments of the device, the one or more sensors further comprise two or more strain gauge sensors spaced apart from one another. At least one intermediate element is positioned between two strain gauge sensors. Said intermediate element is the light source member or the light detector member of at least one of said one or more lightbased sensing arrangements.

[0099] In some embodiments of the device, the one or more sensors further comprise two or more strain gauge sensors spaced apart from one another. The device further comprises one or more second type of sensors, the second type of sensors is a PPG sensor. The light source and the light detector of the PPG sensor are arranged a long a line that is positioned between two strain gauge sensors. It is to be noted that there may be more than one PPG sensor that are positioned between two adjacent strain gauge sensors.

[0100] In some embodiments of the device, said pliable pad extends along a pad axis defined between first and second ends of the wrist-bearing surface. The pad axis is typically the longitudinal axis that is defined as an axis parallel to one extending along a wristband which may be associated with or coupled to the pliable pad and is used to fix the pliable pad to the wrist. The two or more strain gauge sensors are spaced-apart along said pad axis. Namely, one of the strain gauge sensors is positioned at a first position along the pad axis and another strain gauge sensor is positioned at a second position along the pad axis, wherein the light-based sensor is positioned between them along the pad axis. It is to be noted that the members of the light-based sensor may be arranged along an axis different than the pad axis, and typically normal to the pad axis on a plane defined by the wrist-bearing surface.

[0101] In some embodiments of the device, the intermediate element and its respective member, which can be either a light source or a light detector of the light-based sensor, are aligned along a light-based sensor axis on the wrist-bearing surface normal to said pad axis.

[0102] In some embodiments of the device, the pliable pad comprises a base surface opposite to the wrist-bearing face. The base surface comprises wristband-bearing portions spaced apart from one another, facing away from the wrist-bearing face and intended to be positioned on a wristband, when the device is fitted on the wristband. The wristbandbearing portions defines a wristband-bearing portions plane, and a plurality of voids are formed between said wristband-bearing portions plane and the base surface. Namely, a void is formed between two adjacent wristband-bearing portions.

[0103] In some embodiments of the device, the pliable pad comprises one or more structure elements formed in a portion of the pad that does not include the wrist-bearing surface and having each an outer face, the outer faces of all the structure elements jointly define a base surface that is opposite the wrist-bearing surface, the base surface has one or more discontinuities defined by one or more voids between said elements. Namely, the pliable pad comprises a structure that defines said base surface which in use bears against an external element such as a wristband or another element that pushes the pad and, hence, its wrist-bearing surface against a wrist of the subject for obtaining measurements indicative of physiological parameters.

[0104] In some embodiments of the device, the discontinuities are grooves that extend between opposite sides of the pad in a direction normal to a pad axis defined between first and second ends of the pliable pad, the sides of the pad are those that extend along an axis substantially parallel to the pad axis.

[0105] In some embodiments of the device, the structure elements are two or more ribs spaced-apart by one or more voids. The voids are gaps or spaces that are formed between the ribs. Therefore, the pliable pad can be seen as a bulk of material that has a plurality of cut-out portions that define the ribs that are spaced-apart by these cut portions. When bending around a wrist this ribbed structure allows the outer portions of the rib to move away from one another thereby permitting the whole pliable pad to be bend around the wrist portion of the subject to conform with its contour, with minimal strain at said base surface.

[0106] In some embodiments of the device, the ribs extend between opposite sides of the pad in a direction normal to the pad axis. The direction normal to the pad axis should be understood as a direction along an axis that is parallel to a normal axis that is normal to the pad axis on a plane defined by the wrist-bearing surface.

[0107] In some embodiments of the device, at least one of said voids extends between a first side and a second of said opposite sides of the pad; said at least one void defines two first sections and a second section, each of the first sections extends between a respective side of said opposite sides and the second section. In other words, the first sections are the sections that are defined in the periphery and extend from the side of the pliable pad to the second section that is in between these two first sections. The sections are continuous and there is no discernable transition between the first sections and the second section other than the shape and the depth of the sections. The second section extends to a greater extent along a vertical axis than the first sections. Said vertical axis is defined normal to a plane defined by the opposite surface. Namely, the second section is deeper than the first sections. This is made to allow the central portion of the pliable pad, and in particular the wrist-bearing surface, to be the most flexible as the thickness of the pliable pad in this portion is minimal.

[0108] In some embodiments of the device, at least one of the voids, extending between said base surface and an inner end of the void, has at least one deeper inner end portion that is closer to the wrist-bearing surface than other portions of the inner end.

[0109] In some embodiments of the device, said deeper inner portion is located opposite one of said one or more sensors.

[0110] In some embodiments of the device, the at least one of the voids comprise two first sections flanking a second section, the inner end of the second portion is closer to the wrist-bearing surface than that of the two first sections. In other words, the first sections are the sections that are defined in the periphery and extend from the side of the pliable pad to the second section that is in in between these two first sections. The sections are continuous and there is no discernable transition between the first sections and the second section other than the shape and the depth of the sections. Namely, the second section is deeper than the first sections. This is made to allow the central portion of the pliable pad, and in particular the wrist-bearing surface, to be the most flexible as the thickness of the pliable pad in this portion is minimal.

[0111] In some embodiments of the device, the second section is located opposite, or below, one of said one or more sensors along said vertical axis. The term “below” should be understood as the direction from the one or more sensors towards the base surface.

[0112] In some embodiments of the device, the voids have a width which is greater in said second section than in said the first sections, namely the second section extends along the pad axis to a greater extent than the first section.

[0113] In some embodiments of the device, the inner end of the second section has a general shape corresponding to that of said one of said one or more sensors. The general shape of said one of said one or more sensors should be understood as that it encompasses the majority of the projection of said one of said one or more sensors, e.g. above 50%, 60%, 70%, or 80% of the projection.

[0114] In some embodiments of the device, the pliable pad is a single-piece molded or printed article.

[0115] In some embodiments of the device, the pliable pad is made of a pliable, flexible or elastomeric material.

[0116] In some embodiments of the device, the pliable pad is made of silicone -based material.

[0117] In some embodiments of the device, the pliable pad is made of silicone rubber.

[0118] In some embodiments of the device, said one or more sensors are attached to or fitted on said wrist-bearing surface. It is to be noted that the one or more sensors may be attached to the wrist-bearing surface while it is covered by a protective cover for protecting it.

[0119] In some embodiments of the device, the pliable pad is fitted on or is configured for fitting on a wrist-facing side of a wrist-fitting element, e.g. a wristband or bracelet.

[0120] In some embodiments, the device further comprises a coupling member attached to or fitted over a wrist-fitting element, or a wristband or bracelet fitting element, that extends around the wrist or a portion thereof along an element axis or configured for such attachment or fitting, namely the coupling member comprises wristband receiving portions for receiving the wristband therethrough for said attachment or fitting. The pliable pad is (i) attached to said coupling member, and (ii) extending along a pad axis parallel to said element axis. Said pad axis is the same axis as the pad axis defined between two ends of the wrist-bearing surface.

[0121] In some embodiments of the device, the coupling member is made of silicone- based material, such as silicone or silicone rubber.

[0122] In some embodiments of the device, the coupling member has greater hardness than the pliable pad.

[0123] In some embodiments of the device, said coupling member comprises two fitting or receiving portions extending from a body portion, each fitting portion having an opening for fitting around the wrist-fitting element or for receiving the wrist-fitting element therethrough. Therefore, the fitting portions, when the wrist-fitting element, e.g. a wristband, is received therethrough, have a first part that is on a wrist-facing side of the coupling member and a second part that is on an opposite side, namely the side facing away from the wrist of the subject. The fitting portions and the body portion are typically elements of one integral structure.

[0124] In some embodiments of the device, each of the fitting portions comprises a wristfacing face. One or both of the wrist-facing faces comprises a first ECG electrode for providing an ECG contact point while the device and the pliable pad bear against the skin of the subject.

[0125] In some embodiments of the device, the body comprises an external face and a vertical axis is defined normal to said external face, the vertical axis defined herein is the same vertical axis defined with respect to the opposite surface. The one or more sensors are positioned at a greater extent from the external face than the wrist-facing faces along said vertical axis in a wrist direction, defining the direction to the wrist.

[0126] In some embodiments of the device, the body portion comprises an external face that comprises one or more second ECG electrodes, thereby allowing the subject to touch the second ECG electrode with a body part, such as a finger, from an opposite side of the body than the hand wearing the device to allow and ECG measurement by the first and second ECG electrodes.

[0127] In some embodiments of the device, the body portion, when fitted or attached to the wristband, is entirely positioned at an outer side of the wristband, the outer side is being further away from the wrist than an inner side of the wristband.

[0128] In some embodiments of the device, the pliable pad is attached to, and typically only to, the wristband fitting portions. The attachment is made to the parts of the wristband receiving portions that are on the inner side of the wristband. Therefore, the pliable pad is merely attached at its two ends, maintaining its freedom to bend in order to conform with the skin shape of the subject.

[0129] In some embodiments of the device, the pliable pad comprises wristband-bearing portions bearing against the wristband when it is attached to or fitted to the wristband. These wristband-bearing portions are typically the portions at the opposite surface formed by the ribs.

[0130] In some embodiments of the device, said wristband-bearing portions are defined by a base surface opposite the wrist-bearing surface. In other words, a gap is spanned between the wrist-facing surface of the body portion of the coupling member and the wristband-bearing portions of the pliable pad. The wristband or the wrist-fitting element that is received into the wrist-fitting portions fits through this gap such that it is sandwiched between the wrist-facing surface of the body portion of the coupling member and the wristband-bearing portions of the pliable pad. Therefore, when received, a portion of the wrist-fitting element extends through a first wrist-fitting portion, the gap, and the second wrist-fitting portion.

[0131] In some embodiments of the device, the coupling member is pliable or flexible.

[0132] In some embodiments of the device, the pliable pad is more pliable or flexible with respect to the coupling member, namely the pliability or flexibility degree of the pliable pad are higher than these of the coupling member.

[0133] In some embodiments of the device, said pliable pad is integrally formed on said wrist band.

[0134] In some embodiments of the device, said pad is integrally formed on the inner side of the wristband and extending along a wristband axis.

[0135] In some embodiments, the device further comprises an electronic utility for receiving and processing said output signal and for emitting a data signal based thereon.

[0136] In some embodiments of the device, the physiological parameter is one causing skin deformations.

[0137] In some embodiments of the device, the physiological parameter is a cardiovascular parameter.

[0138] In some embodiments of the device, said physiological parameter is a heartbeat- induced pressure change in the vasculature in said skin portion or respiration rate. In some embodiments of the device, said wrist-bearing surface has a varying pliability between a central portion thereof towards its periphery.

[0139] In some embodiments of the device, the flexibility or pliability of the wristbearing surface is higher in the central portion than in the periphery.

[0140] Yet another aspect of the present disclosure provides a method for measuring a physiological parameter from a skin portion of a subject. The method comprises contacting, directly or indirectly, the contact surface of a sensor device according to any one of the above-described embodiments or any combination thereof; and outputting said output signal.

[0141] Yet another aspect of the present disclosure provides a device for measuring a physiological parameter. The device comprises a pliable pad with a pliable wrist-bearing surface configured for placing against a portion of the wrist and a base opposite thereto, the base being configured to permit the wrist-bearing surface to fit the contours of the wrist; and one or more sensors disposed on, within or associated with said pad for sensing at least one of (i) change of pressure on the pad, (ii) deformation of the wrist-bearing surface, (iii) change of pressure applied on said one or more sensors or, (iv) deformation of said one or more sensors, and for issuing an output signal corresponding thereto indicative of said physiological parameter or a change thereof.

[0142] EMBODIMENTS

[0143] The following are optional embodiments and combinations thereof in accordance with aspects of the present disclosure:

[0144] 1. A sensor device for measuring a physiological parameter or a data indicative of said physiological parameter from a skin portion of a subject, the sensor device comprising: a carrier defining a contact surface for contacting directly or indirectly said skin portion; a patterned layer of graphene disposed on or embedded in said carrier, such that one or both of (i) pressure applied on said layer, and (ii) deformation of said layer, results in a change of at least one electrical parameter of said layer; wherein the change of the at least one electrical parameter of said layer is indicative of said physiological parameter or a change thereof.

[0145] 2. The sensor device of embodiment 1, the physiological parameter is one causing skin deformations.

[0146] 3. The sensor device of embodiment 2, wherein the physiological parameter is a cardiovascular parameter.

[0147] 4. The sensor device of embodiment 3, wherein said physiological parameter is a heartbeat-induced pressure change in the vasculature in said skin portion or respiration rate.

[0148] 5. The sensor device of any one of embodiments 1 to 4, wherein said carrier is a planar substrate.

[0149] 6. The sensor device of any one of embodiments 1 to 5, wherein said carrier is pliable, flexible or deformable.

[0150] 7. The sensor device of any one of embodiments 1 to 6, wherein said carrier comprises poly-oxydiphenylene-pyromellitimide, and said patterned layer of graphene is formed on the surface of said carrier by laser etching.

[0151] 8. The sensor device of any one of embodiments 1 to 7, wherein said patterned layer defines one or more continuous paths, the electrical parameter being determined between two space-apart points in such one or more paths.

[0152] 9. The sensor device of any one of embodiments 1 to 8, comprising an electronic circuitry coupled to said layer and configured for reading the at least one electrical parameter of said layer, and for outputting a signal corresponding thereto or corresponding to a change in said parameter.

[0153] 10. The sensor device of embodiment 9, wherein said electronic circuitry comprises a processor configured for processing the read at least one electrical parameter for determining said physiological parameter, said outputting comprises outputting data corresponding to said or representative of said physiological parameter.

[0154] 11. The sensor device of any one of embodiments 1 to 10, wherein the at least one electrical parameter is selected from any one of: resistance, conductance, capacitance, electrical potential, impedance, or any combination thereof.

[0155] 12. The sensor device of any one of embodiments 1 to 10, comprising two or more of said carriers. 13. A method for measuring a physiological parameter from a skin portion of a subject, comprising: contacting, directly or indirectly, a contact surface of a sensor device with said skin portion, the sensor device comprises: a carrier defining said contact surface, and a patterned layer of graphene disposed on or embedded in said carrier, such that one or both of (i) pressure applied on said layer, and (ii) deformation of said layer, results in a change of at least one electrical parameter of said layer; measuring said change of at least one electrical parameter and generating sensed data representative thereof; and outputting said sensed data.

[0156] 14. The method of embodiment 13, comprising analyzing said change of at least one electrical parameter of said layer for determining said physiological parameter.

[0157] 15. The method of embodiment 13 or 14, wherein said sensor device is any one of embodiments 1 to 12.

[0158] 16. A device for measuring a physiological parameter, comprising: a pliable pad fitted or being configured for fitting on a wrist-facing side of a wristband, the pad having a pliable wrist-bearing surface and configured for placing against a portion of the wrist; and one or more sensors disposed within or associated with said pad for sensing at least one of (i) change of pressure within or on the pad, and (ii) deformation of the wristbearing surface, (iii) change of pressure applied on said one or more sensors or, (iv) deformation of said one or more sensors, and for issuing an output signal corresponding thereto indicative of said physiological parameter or a change thereof.

[0159] 17. The device of embodiment 16, comprising: a base attached to or fitted over an inner, wrist-facing face of a wristband that extends along a wristband axis or configured for such attachment or fitting; and wherein said pad (i) being attached to said base, and (ii) extending between first and second edges thereof along a pad axis parallel to said wristband axis.

[0160] 18. The device of embodiment 16 or 17, wherein said pad is integrally formed on said wrist band.

[0161] 19. The device of embodiment 18, wherein said pad is integrally formed on the inner side of the wristband and extending along a wristband axis. 20. The device of any one of embodiments 16 to 19, comprising an electronic utility for receiving and processing said output signal and for emitting a data signal based thereon.

[0162] 21. The device of any ne of embodiments 16 to 20, wherein the physiological parameter is one causing skin deformations.

[0163] 22. The device of embodiment 21, wherein the physiological parameter is a cardiovascular parameter.

[0164] 23. The sensor device of embodiment 21 or 22, wherein said physiological parameter is a heartbeat-induced pressure change in the vasculature in said skin portion or respiration rate.

[0165] 24. The device of any one of embodiments 16 to 23, wherein the pad is a fluid-filled enclosure having a pliable wrist-bearing surface.

[0166] 25. The device of embodiment 24, wherein the pad is configured such that deformation of central portion of the wrist-bearing surface will not substantially deform edge portions thereof.

[0167] 26. The device of any one of embodiments 16 to 25, wherein said wrist-bearing surface has a varying pliability between a central portion thereof towards its periphery.

[0168] 27. The device of embodiment 26, wherein the flexibility or pliability of the wristbearing surface is higher in the central portion than in the periphery.

[0169] 28. The device of any one of embodiments 16 to 27, wherein the pad is elongated and is tracing a circumferential portion of the wrist.

[0170] 29. The device of embodiment 28, wherein the pad has an overall accurate shape to trace contours of the wrist.

[0171] 30. The device of any one of embodiments 16 to 29, wherein said sensor comprises a pliable element that changes its impedance upon deformation thereof and comprises an electronic circuitry for measuring the impedance and / or changes in impedance and issuing an output signal corresponding thereto, and wherein said pliable element is fitted within said pad or is associated with the wrist-bearing surface such that one or both of (i) change of pressure of the fluid and (ii) deformation of the wrist fitting surface, deforms said pliable device.

[0172] 31. The device of embodiment 30, wherein the pliable element is fitted on the wristbearing surface. 32. The device of embodiment 30, wherein the pliable element is embedded within said pad.

[0173] 33. The device of any one of embodiments 30 to 32, wherein said pliable element comprises a strain gauge.

[0174] 34. The device of any one of embodiments 30 to 32, wherein said pliable element comprises the sensor device of any one of embodiments 1 to 15.

[0175] 35. The device of any one of embodiments 30 to 34, comprising two or more of said pliable elements.

[0176] 36. The device of embodiment 35, comprising two or more of said pliable elements at least two of which are disposed in a parallel arrangement whereby a first of a parallel pair is overlying a portion of the wrist that is more proximal, with respect to the direction of arterial blood flow, than a second of the pair.

[0177] 37. The device of any one of embodiments 16 to 29, wherein said senor comprises a piezoelectric element.

[0178] 38. The device of embodiment 37, wherein the piezoelectric element is disposed on or against a flexible surface associated with said pad and undergoes deformations upon one or both of (i) pressure changes within the pad and (ii) deformation of the wrist fitting surface.

[0179] 39. The device of any one of embodiments 16 to 38, wherein said pad is divided into two or more separate compartments, parallel to one another, and wherein each compartment comprises separate one or more of said sensors for measuring one or both of (i) change of pressure within the compartment, and (ii) deformation of the wrist fitting surface of said compartment, and for issuing an output signal corresponding thereto.

[0180] 40. The device of any one of embodiments 16 to 39, comprising a power source.

[0181] 41. The device of any one of embodiments 16 to 40, configured for connection to an external power source.

[0182] 42. The device of any one of embodiments 16 to 41, comprising a wireless transmitting utility configured for transmitting said output signal to another device.

[0183] 43. The device of embodiment 42, wherein said wireless transmitting utility is a low- power Bluetooth transceiver. 44. The device of embodiment 41 or 42, wherein the wireless transmitting utility is configured for transmitting said output signal to one or more of a smart watch, a mobile communication device and a computer.

[0184] 45. The device of any one of embodiments 16 to 44, comprising a wired transmitting utility configured for wired transmission of said data signal to a smart watch.

[0185] 46. The device of any one of embodiments 16 to 45, wherein said one or more sensors are printed on the pliable wrist-bearing surface.

[0186] 47. The device of embodiment 46, wherein the printed one or more sensors are covered by a protective cover.

[0187] 48. The device of embodiment 47, wherein the protective cover is made of the same material as the pliable pad.

[0188] 49. The device of any one of embodiments 16-48, wherein said one or more sensors are one or more of said sensor device of any one of embodiments 1-15.

[0189] 50. The device of any one of embodiments 16 to 48, wherein said one or more sensors comprise at least one light source and at least one light detector, the at least one light source is positioned so as to illuminate an internal volume of the pliable pad, and the at least one light detector is positioned so as to detect the illumination response of the illumination of the light source with the internal volume of the pliable pad.

[0190] 51. The device of embodiment 50, wherein a sensing surface of the at least one light detector is outside the illuminated image region of the light source.

[0191] 52. The device of embodiment 50, wherein the optical field of view of the light detector includes the illuminated image region of the light source.

[0192] 53. The device of any one of embodiments 50-52, wherein at least part or the entire of the pliable pad is covered with an optical reflecting material causing a reflection of the illumination of the light source.

[0193] 54. The device of any one of embodiments 50-53, wherein said at least one light source comprises at least one light-emitting-diode (LED) and said at least one light detector comprises at least one photodiode (PD).

[0194] 55. The device of any one of embodiments 50-54, wherein the at least one light source and the at least one light detector are positioned such that one of them is disposed on the wrist-bearing surface or in proximity thereto and the other is disposed on an opposite surface to the wrist-bearing surface or in proximity thereto. 56. The device of any one of embodiments 50-55, wherein the at least one light source and the at least one light detector are positioned such that their optical axes are normal to the plane spanned by the wrist-bearing surface.

[0195] 57. The device of any one of embodiments 50-56, comprising a light blocking element disposed within the pliable pad, and positioned such that it proportionally blocks an amount of light emitted from the light source from reaching to the light detector,

[0196] 58. The device of any one of embodiments 50-57, wherein the at least one light source is positioned partially or entirely outside the pliable pad.

[0197] 59. The device of any one of embodiments 50-58, wherein the at least one light detector is positioned partially or entirely outside the pliable pad.

[0198] 60. The device of embodiment 16-59, wherein the one or more sensors comprise one or more strain gauge sensors.

[0199] 61. The device of embodiment 16-60, wherein the one or more sensors comprise one or more light-based sensing arrangements, each of which comprises: a light source member configured to emit light at a defined wavelength; a light detector member configured to detect response to illumination at said defined wavelength.

[0200] 62. The device of embodiment 61, wherein said one or more light-based sensing arrangements are PPG sensors.

[0201] 63. The device of embodiment 61 or 62, wherein the one or more sensors further comprise two or more strain gauge sensors spaced apart from one another; at least one intermediate element is positioned between two strain gauge sensors; and wherein said intermediate element is the light source member or the light detector member of at least one of said one or more light-based sensing arrangements.

[0202] 64. The device of embodiment 63, wherein said pliable pad extends along a pad axis defined between first and second ends of the wrist-bearing surface; wherein the two or more strain gauge sensors are spaced-apart along said pad axis.

[0203] 65. The device of embodiment 63 or 64, wherein the intermediate element and its respective member are aligned along a light-based sensor axis on the wrist-bearing surface normal to said pad axis. 66. The device of any one of embodiments 16-66, wherein the pliable pad comprises a base surface opposite to the wrist-bearing face, the base surface comprises wristbandbearing portions spaced apart from one another, facing away from the wrist-bearing face and intended to be positioned on a wristband, when the device is fitted on the wristband; the wristband-bearing portions defines a wristband-bearing portions plane, and a plurality of voids are formed between said wristband-bearing portions plane and the base surface.

[0204] 67. The device of any one of embodiments 16-65, wherein the pliable pad has one or more structure elements formed in a portion of the pad that does not include the wristbearing surface and having each an outer face, the outer faces of all the structure elements jointly define a base surface that is opposite the wrist-bearing surface, the base surface has one or more discontinuities defined by one or more voids between said elements.

[0205] 68. The device of embodiment 67, wherein the discontinuities are grooves that extend between opposite sides of the pad in a direction normal to a pad axis defined between first and second ends of the pliable pad.

[0206] 69. The device of embodiment 67 or 68, wherein the structure elements are two or more ribs spaced-apart by one or more voids.

[0207] 70. The device of embodiment 69, wherein the ribs extend between opposite sides of the pad in a direction normal to the pad axis.

[0208] 71. The device of embodiment 66 or 69, wherein at least one of said void extends between a first side and a second of said opposite sides of the pad; said at least one void defines two first sections and a second section, each of the first sections extends between a respective side of said opposite sides and the second section; wherein the second section extends to a greater extent along a vertical axis than the first sections; wherein said vertical axis is defined normal to a plane defined by the opposite surface.

[0209] 72. The device of embodiment 66 or 69, wherein at least one of the voids, extending between said base surface and an inner end of the void, has at least one deeper inner end portion that is closer to the wrist-bearing surface than other portions of the inner end.

[0210] 73. The device of embodiment 72, wherein said deeper inner portion is located opposite one of said one or more sensors.

[0211] 74. The device of embodiment 72 or 73, wherein the at least one of the voids comprise two first sections flanking a second section, the inner end of the second portion is closer to the wrist-bearing surface than that of the two first sections. 75. The device of embodiment 74, wherein the second section is located opposite one of said one or more sensors along said vertical axis.

[0212] 76. The device of embodiment 75, wherein the voids have a width which is greater in said second section than in said the first sections.

[0213] 77. The device of embodiment 75 or 76, wherein the inner end of the second section has a general shape corresponding to that of said one of said one or more sensors.

[0214] 78. The device of any one of embodiments 16-77, wherein the pliable pad is a single piece molded or printed article.

[0215] 79. The device of any one of embodiments 16-78, wherein the pliable pad is made of a pliable, flexible or elastomeric material.

[0216] 80. The device of any one of embodiments 16-79, wherein the pliable pad is made of silicone-based material.

[0217] 81. The device of embodiment 80, wherein the pliable pad is made of silicone rubber.

[0218] 82. The device of any one of embodiments 16-81, wherein said one or more sensors are attached to or fitted on said wrist-bearing surface.

[0219] 83. The device of any one of embodiments 16-82, wherein the pliable pad is fitted on or is configured for fitting on a wrist-facing side of a wrist-fitting element.

[0220] 84. The device of any one of embodiments 16-83 comprising: a coupling member attached to or fitted over a wrist-fitting element that extends around the wrist or a portion thereof along an element axis or configured for such attachment or fitting; and wherein said pliable pad (i) being attached to said coupling member, and (ii) extending along a pad axis parallel to said element axis.

[0221] 85. The device of embodiment 84, wherein said coupling member comprises two fitting portions extending from a body portion, each fitting portion having an opening for fitting around the wrist-fitting element.

[0222] 86. The device of embodiment 85, wherein each of the fitting portions comprises a wrist-facing face; wherein one or both of the wrist-facing faces comprises a first ECG electrode.

[0223] 87. The device of embodiment 86, wherein the body comprises an external face and a vertical axis is defined normal to said external face; wherein the one or more sensors are disposed at a greater extent from the external face than the wrist-facing faces along said vertical axis in a wrist direction. 88. The device of any one of embodiments 85-87, wherein the body portion comprises an external face that comprises one or more second ECG electrodes.

[0224] 89. The device of any one of embodiments 85-88, wherein the body portion, when being fitted or attached to the wristband, is entirely positioned at an outer side of the wristband, the outer side is being further away from the wrist than an inner side of the wristband.

[0225] 90. The device of any one of embodiments 85-89, wherein the pliable pad is attached to the wristband fitting portions.

[0226] 91. The device of any one of embodiments 85-90, wherein the pliable pad comprises wristband-bearing portions bearing against the wristband when it is attached to or fitted to the wristband.

[0227] 92. The device of embodiment 91, wherein said wristband-bearing portions are defined by a base surface opposite the wrist-bearing surface.

[0228] 93. The device of any one of embodiments 84-92, wherein the coupling member is pliable or flexible.

[0229] 94. The device of embodiment 93, wherein the coupling member is made of silicone- based material.

[0230] 95. The device of embodiment 93 or 94, wherein the pliable pad is more pliable or flexible with respect to the coupling member.

[0231] 96. A method for measuring a physiological parameter from a skin portion of a subject, comprising: contacting, directly or indirectly, the contact surface of a sensor device according to any one of embodiments 16-95; and outputting said output signal.

[0232] BRIEF DESCRIPTION OF THE DRAWINGS

[0233] 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: Figs. 1A-1B are schematic illustrations of cross-sectional views exemplifying an embodiment of the device according to an aspect of the present disclosure. Fig. 1A is a transverse cross section of the device and Fig. IB is a longitudinal cross section of the device.

[0234] Fig. 2 is a schematic illustration of a transverse cross-sectional view exemplifying an embodiment of the device according to an aspect of the present disclosure.

[0235] Figs. 3A-3D are schematic illustrations of different views of a non-limiting example of an embodiment of a device for measuring a physiological parameter according to an aspect of the present disclosure. The illustrations are provided in a transparency mode, allowing to view through elements. Fig. 3A is a perspective view; Fig. 3B is a side view; Fig. 3C is a top view; and Fig. 3D is a front view.

[0236] Fig. 4 is a schematic illustration exemplifying the device being fitted over a wristband of a watch by its base.

[0237] Fig. 5 is a schematic illustration of a transverse cross-sectional view exemplifying an embodiment of the device according to an aspect of the present disclosure.

[0238] Figs. 6A-6B are schematic illustrations of different views of an example of a nonlimiting embodiment of the sensor device according to an aspect of the present disclosure . Fig. 6A is a cross-sectional view; and Fig. 6B is a top view.

[0239] Fig. 7 is a schematic illustration of a transverse cross-sectional view exemplifying an embodiment of the device according to an aspect of the present disclosure.

[0240] Figs. 8A-8F are schematic illustrations of different embodiments of non-limiting examples of realizations of the sensors of the pliable pad.

[0241] Figs. 9A-9F are schematic illustrations of different views of a non-limiting example of an embodiment of the device for measuring a physiological parameter according to an aspect of the present disclosure. Fig. 9A is a perspective view; Fig. 9B is a side view; Fig. 9C is a top view showing the strain gauge sensors; Fig. 9D is a bottom view; and Fig. 9E is a cross-sectional bottom view of the pliable pad, and Fig. 9F is a perspective view of the isolated base.

[0242] Figs. 10A-10B are schematic illustrations of different views of another embodiment of the device for measuring a physiological parameter. Fig. 10A is a perspective view and Fig. 10B is a top view showing the light-based sensing arrangements. Figs. 11A-11C are schematic illustrations of different views of another embodiment of the device for measuring a physiological parameter showing the hybrid configuration of strain gauge sensors, light-based sensors, and ECG electrodes. Fig. 11A is a perspective view; Fig. 11B is atop view; and Fig. 11C is a bottom view.

[0243] DETAILED DESCRIPTION OF EMBODIMENTS

[0244] The following figures are provided to exemplify embodiments and realization of the invention of the present disclosure.

[0245] Reference is first being made to Figs. 1A-1B, which are schematic illustrations of cross-sectional views exemplifying an embodiment of the device according to an aspect of the present disclosure. The device is intended to be used in sensing movements of a skin of a subject, typically a skin portion that is associated with either the radial artery or the ulnar artery. The movements of the skin portion that is in contact with the device result in application of varying pressure on the device that is indicative of a physiological parameter of the subject, such as heart rate, blood pressure, or respiration rate. Therefore, by sensing accurately the pressure applied by the skin on the device, accurate physiological parameters can be derived in a non-invasive manner. The device 100 comprises a pliable pad 102 having an internal, confined volume 104 filled with pliable material, such as silicone gel, air, grease, or any other suitable pliable material. A portion of external surface 106 of the pliable pad is intended to contact the skin portion SP of the subject. This portion of the external surface 106 can be regarded as a contact surface or a wrist-engaging surface. The device 100 is intended to be either coupled to a wristband or integrated in a wearable device so as to allow the contact of the contact surface 106 with the skin portion SP of the subject. One or more sensors 108 are disposed within the internal volume 104 and are configured to sense change of pressure within the internal volume or change of strain applied on them in result to application of pressure on the contact surface 106. In this example, there are two sensors 108 but it is to be noted that the device is not limited to this number of sensors and there can be only one sensor or more than two sensors in the device. The sensors may be printed in the pliable pad or on the contact surface thereof. For example, the sensors can be strain gauge sensors printed on the contact surface or in proximity to the contact surface. The sensors 108 are extending along the longitudinal axis LA of the device and span the majority of the longitudinal length of the pliable pad 102, as can be best seen in Fig. IB (the transverse plane TP shown in Fig. IB is the plane of which the cross section of Fig. 1A is shown). The sensors are elongated along the longitudinal axis in order to allow them to be placed generally normal to the arteries and ensure that at least a portion of the sensor is placed over the artery. The two sensors 108 can be embedded in the pliable pad 102 such that they are positioned in a common compartment defined by the pliable pad 102, as exemplified in Figs 1A-1B. In some other embodiments, the pliable pad 102 may be divided into sub-compartments, each compartment comprises one of the two sensors 108. This configuration allows to mechanically isolate each compartment such that it is affected only by pressure applied thereto, therefore the measurements by each sensor are relevant only to pressure applied on a contact surface of its compartment. This formation is exemplified in Fig. 5, where the device 500 is exemplified by having a pliable pad 502 that comprises a dividing element 505 that divides the pliable pad 502 into two compartments, each has its own internal volume 504A and 504B, respectively. Each compartment has its own contact surface 506A and 506B and its own sensor 508A and 508B

[0246] Furthermore, by including more than one sensor in the device, the velocity of the propagation of the pulse wave can be measured. For this purpose, the sensors 108 are disposed generally parallel to each other and by analyzing the difference of the time of arrival of the pulse wave to each sensor, the propagation velocity of the pulse wave can be measured and the pule transit time can be calculated based thereon.

[0247] The sensors can be in the form of strain gauge or in the form of piezoelectric sensors. The sensors are generating sensed data indicative of the pressure or strain variation profile applied thereon. The sensed data is transmitted to a processor for further processing it and to extract the physiological parameters of the subject. The processor can be remoted or as part of the device. The sensors are coupled to a power source (not shown) for powering them to allow the measurement and the transmission of the sensed data.

[0248] In the figures throughout the application, 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 Fig. 2 serves the same function as element 102 in Figs. 1A-1B.

[0249] Reference is now made to Fig. 2, which is a schematic illustration of a transverse cross-sectional view exemplifying an embodiment of the device according to an aspect of the present disclosure. The device 200 of Fig. 2 differs from that of Figs. 1A-1B by (i) exemplifying that portions of the sensors 208 are flush with the contact surface 206 or even projecting over the contact surface 206 and (ii) including a base structure 210 supporting the pliable pad 202 from an opposite side of the contact surface 206. It is to be noted that the sensors 208 may be covered by a protective fdm that is made of the material of the pliable pad or other material. The protective fdm ensures that the skin portion that applies pressure on the pliable pad does not directly contacts the sensors 208. The base structure 210 is more rigid than the pliable pad 202 and in this example comprises electrical components 212, such as a PCB and power source, that are coupled to the sensors 208 by electrical wirings 214. The support structure 210 can be coupled to a wristband or integrated into a wearable device.

[0250] Reference is now made to Fig. 7, which is a schematic illustration of a transverse cross-sectional view exemplifying an embodiment of the device according to an aspect of the present disclosure. In this example, the sensors 708 are applied on the contact surface 706 of the pliable pad 702, namely on an external surface of the pliable pad 702. It is to be noted that the pliable pad can be fdled with a non-volatile or non-drying solution to grant it the pliable properties.

[0251] Reference is now made to Figs. 3A-3D, which are schematic illustrations of different views of a non-limiting example of an embodiment of a device for measuring a physiological parameter according to an aspect of the present disclosure. The device 300 comprises a pliable pad 302 that is disposed on a base 310. The pliable pad 302 comprises an internal, confined volume 304. Two sensor elements, in the form of strain gauges elements 308, are disposed within the internal volume 304. The pliable pad 302 comprises a contact surface 306 that may be made of the same material that fills the internal volume 304 or different. Application of pressure on the contact surface results in a pressure or strain change within the internal volume. The strain gauges elements 308 are configured to sense the variation profile of the strain or pressure within the internal volume 304, therefore the sensing by the sensor elements 308 is indicative of the pressure applied on the contact surface 306. The strain gauges 308 are extending along a longitudinal axis LA of the device 300, each along a different edge 316A / 316B of the device 300, and therefore the two sensor elements 308 are parallel one to another. In this example, one of the sensors is positioned more forward than the other sensor along the longitudinal axis LA. This is done in case that the sensor element size is less than the entire length of the device or the pad so as to effectively increase the sensing area, and therefore, the chance to position the sensors on the skin portion associated with the artery. There is a certain distance D between the two sensor elements 308, and in case that the two sensors 308 sense the pulse wave, the time difference between the sensing of the pulse wave in each sensor can lead to velocity of the propagation of the pulse wave, which is indictive of some physiological parameters of the subject, such as pulse transient time.

[0252] The base 310 is designed to be received by a wristband (not shown), such as a wristband of a watch. By fitting the base 310 over the wristband, the contact surface 306 faces the skin portion of the wrist of the subject and therefore the measurement by the device can be performed.

[0253] The pliable pad 302 may have a varying pliability such that similar pressure intensity that is applied on the different parts of the contact surface 306 results in different pressure or strange difference within the internal volume 304 of the pliable pad 302. This can be realized by forming different parts of the pliable pad 302 from different materials, different material density, or a combination thereof. In some embodiments, the contact surface may a varying geometry such at a center portion of the contact surface it reaches to a first, upper level and at periphery portions of the contact surface it reaches to a second, lower level, when the device is oriented such that the contact surface faces the up direction.

[0254] Reference is now being made to Figs. 8A-8D, which are schematic illustrations of different embodiments of non-limiting examples of realizations of the sensors of the pliable pad. In these examples, the sensors 808 are constituted by a light-emitting-diode (LED) 808 A and a photodiode (PD) 808B. The LED 808A emits light towards the internal volume 804 of the pliable pad 802 and the PD 808B detects a portion of the emitted light. The portion that is detected by the PD is varied according to the extent of pressure that is applied on the contact surface 806 of the pliable pad 802. Therefore, the amount of detected light by the PD is proportional to the pressure applied on the contact surface 806. In these examples, the internal volume 804 of the pliable pad 802 is required to be filled with a material or substance that is transparent or at least partially transparent for the light emitted from the LED.

[0255] Fig. 8 A shows an embodiment in which the LED 808 A and the PD 808B are positioned on opposite side edges 817A and 817B of the pliable pad 802, respectively, such that the optical axis OA of the LED 808A is in the field of view FOV of the PD 808B. In this specific example, the LED 808A is directly facing the PD 808B. Application of pressure on the contact surface 806 causes distortion of the light paths through medium in the internal volume 806, which can be a non-volatile or non-drying solution, that affects the amount of light detected by the PD 808B and therefore the pressure change overtime can be determined. It is to be noted that the measurement does not provide absolute values, but relative changes of pressure that is applied on the contact surface.

[0256] Fig. 8B differs from Fig. 8A by that the LED 808A and the PD 808B are positioned on edges of the pliable pad that are either the contact surface or parallel thereto . In this example, the PD 808B is positioned on the internal side of the contact surface 806 and the LED 808A is positioned on the edge opposite the contact surface 806A. It is to be noted that the LED and the PD can switch in their positions.

[0257] Fig. 8C differs from Fig. 8A by that that the pliable pad 802 further comprises a light blocking element 819 disposed between the LED 808A and the PD 808B. The light blocking element may be disposed in its rest state such that a portion thereof is found along the optical axis OA of the LED 808A or can be above or below the optical axis OA. The light blocking element is positioned such that it blocks light emitted from the LED 808A towards the PD 808B proportionally to the pressure applied on the contact surface 806. The greater the pressure, the greater the blocking element moves away from the optical axis OA towards the edge opposite the contact surface 806 and therefore less light is detected by the PD 808B. The light blocking element 819 enhances the effect of the sensor and may increase its sensitivity. It is to be noted that the light blocking element can be realized also when the orientation of the LED and the PD is as exemplified in Fig. 8B

[0258] Fig. 8D differs from Fig. 8A by that that the LED 808A and the PD 808B are positioned on the same edge, in this example on the internal side of the contact surface 806. Therefore, light emitted from the LED 808A scatters in the internal volume 804 and is detected in the PD 808B. There is no direct illumination from the LED 808A and the PD 808B, namely the field of view FOV of the PD 808B does not encompass the light emitting surface of the LED 808A. It is to be noted that LED and the PD may be positioned in the same manner on any edge of the pliable pad 802, either it is a side edge or an edge opposite the contact surface 806.

[0259] Figs. 8E-8F exemplify embodiments of the pliable pad 802, wherein the LED 808A and the PD 808B are positioned externally to the internal volume 804 of the pliable pad 802 such that the LED 808A illuminates into the internal volume 804 from outside the pliable pad 802 and the PD 808B detects light that propagates from the internal volume 804 outside the pliable pad 802 from a specific selected portion in which the PD 808B is positioned.

[0260] It is to be noted that any combination of the above-described embodiments of Figs. 8A-8F can be realized, and the present disclosure is not restricted to the specific embodiments exemplified in the figures.

[0261] Reference is now being made to Fig. 4, which is a schematic illustration exemplifying the device being fitted over a wristband of a watch by its base. The device 400 can be of any of the embodiments described above with respect to Figs. 1-3. In this example, the contact surface 406 of the pliable pad 402 has a central portion 407 that levels above peripheral portions 409 and the central portion 407 is more pliable than the peripheral portions 409.

[0262] Reference is now made to Figs. 6A-6B, which are schematic illustrations of different views of a non-limiting embodiment of a sensor device according to an aspect of the present disclosure. The sensor device 650 comprises a carrier 652 that defines a contact surface 654 for coming into contact with an entity that applies time -varying pressure thereon. The entity may be a skin portion of the subject or an element that transfers the pressure applied thereon to the contact surface 654.

[0263] A patterned layer of graphene 656 is either disposed on the contact surface 654 or embedded within the confined volume 658 defined by the carrier 652. In this example, the layer is disposed within the confined volume 658 of the carrier 652 proximal to the contact surface 654. It is to be noted that in other embodiments, the layer of graphene 656 can be applied directly on the contact surface 654. The layer of graphene 656 is patterned, in this example in a serpentine pattern. This pattern is made to allow a maximum length of a path defined by the graphene on a given surface area. The graphene layer 656 has inherent electrical parameters, e.g. resistance or impedance, and deformation of the layer 656 or a pressure applied on it via the contact surface causes a change of these inherent electrical parameters that correspond to the extent of the applied pressure. In this nonlimiting example, the electrical parameters are measured between two terminals 660A and 660B along the path of the graphene defined by the layer 656. It is to be noted that the measurement can be performed between any two points along the path of the graphene layer 656. Therefore, a pressure applied on the contact surface 654 causes a measurable change of the electrical parameters of the graphene layer 656 indicative of the pressure applied on the contact surface 654. The pressure applied on the contact surface 654 is originated from deformations of a skin portion of the subject that is in contact with the contact surface 654 or with a pressure-mediator elements that transfers the pressure. By measuring the pressure applied by the skin portion on the contact surface, either directly or indirectly, a waveform signal representative of heartbeat of the subject can be determined. By analyzing the waveform signal, a physiological parameter of the subject can be determined. The physiological parameter can be a heart rate, heart rate variability, blood pressure, respiration rate or any other heartbeat related parameter.

[0264] Reference is now made to Figs. 9A-9F, which are schematic illustrations of different views of a non-limiting example of an embodiment of a device for measuring a physiological parameter according to an aspect of the present disclosure. The device 900 comprises a pliable pad 902 that comprises a wrist-bearing surface 915, that is intended to face a wrist of a subject, and a base surface 918 opposite to the wrist-bearing surface 915. The base surface 918 should be understood as all the surface tracing the patterns of the face of the pliable pad 902 that is opposite to the wrist-bearing surface 915. The pliable pad 902 longitudinally extends between a first end 970 and a second end 972 along a longitudinal pad axis PA and transversally extends between a first side 974 and a second side 976 along a transversal axis TA. The pliable pad 902 comprises, on the wrist-bearing surface 915, three sensors 908 in the form of strain gauge sensors. These strain gauge sensors 908 are spaced apart along the pad axis PA, with one sensor positioned at a first position, another at a second position, and a third at a third position along the pad axis PA, wherein the second position is in between the first and the third positions along the pad axis PA. By placing the sensors at different locations, the device can detect deformations of a relatively large area of the wrist-bearing surface resulting from pressure that is applied thereon due to changes in the blood pressure in blood vessels associated with a skin portion that engages the wrist-bearing surface. The spread of three sensors along the pad axis PA ensures that at least one of the sensors will be able to measure the pressure being applied on the wrist-bearing surface, namely that at least one of the sensors will be positioned in a relevant position of the skin portion that is associated with a measurable pressure signal resulted by changes of blood flow in the blood vessel. Typically, the relevant blood vessel is one of the radial or the ulnar artery. Furthermore, by measuring the pressures at various points, a pattern of the pulse wave in the blood vessels beneath the skin can be captured, which may be indicative to a physiological parameter of the subject.

[0265] The base surface 918 comprises bottom, wristband-engaging portions 977 intended for engaging the wristband when the device 900 is fitted on the wristband.

[0266] The pliable pad 902 is connected to a base 910, serving also as a coupling member to a wrist-fitting element such as a wristband, via two contact portions 911 located on opposite sides of the pad axis PA, namely at the first and second ends 970 and 972. The base 910 comprises two wristband-receiving portions 979 extending from a body portion 980. Each of the two wristband-receiving portions 979 is formed with an opening 981 configured to receive a wristband WB therethrough to allow fitting the device 900 on a wristband WB, which may be a wristband of a watch or a stand-alone wristband WB. The base 910 includes a pad-facing surface 982 (or can alternatively be defined also as a wrist-facing surface) and an external surface 983 opposite to the pad-facing surface 982. The wristband WB is received by the device such that it is sandwiched between the base surface 918, and specifically the wristband-engaging portions 977, and the pad-facing surface 982 of the base 910. Therefore, when the device 900 is fitted on a wristband WB, the pliable pad 902, and specifically the base surface 918 rests directly on the wristband WB. When the device is fitted on the wristband WB, the pad axis PA is defined as an axis parallel to one extending along the wristband WB

[0267] In this specific example, the wrist-bearing surface 915 has a convex shape such that the sensor that is positioned in the second position is more elevated than the sensors in the first and third positions. The term “elevated” is used for convenience without any limitation of orientation. In this context, the term “elevated” is used to describe that the sensor in the second position is found at the top of the convex shape of the pliable pad 902.

[0268] The pliable pad 902 comprises voids 920 or cutouts defined by the base surface 918 facing away from the wrist-bearing surface 915. In this example, the voids 920 have a side cross-sectional shape resembling arched windows, with different sizes. The size of the voids 920 decreases with respect to their distance from the center of the pliable pad along the pad axis PA. In other words, the further the void from the center of the pliable pad PA along the pad axis PA, the smaller the void. These voids 920 extend from a plane PL defined by the wristband-engaging portions 977, which is typically a curved plane, toward the base surface 918 along an axis perpendicular to the plane PL. Furthermore, the voids 920 extend from the first side 974 to the second side 976 of the pliable pad 902. Each void 920 has a particular structure - the central portion, namely the middle section 924, of each void has a greater height profile, extending closer to the wrist-bearing surface 915 than the outer portions, namely the edges sections 922, of the same void. In other words, each void has a varying distance between the plane PL and the base surface 918 where it reaches highest in the middle and becomes lower toward the edges. This creates a thinner material layer in the central region of the pliable pad 902 directly beneath each sensor 908, allowing for greater sensitivity to pressure changes and deformations. This makes the pad material thinner in the center and thicker at the edges. When the pad is pressed against the wrist, the thinner central areas can bend and flex more easily, making the sensors more sensitive to small pressure changes. Meanwhile, the thicker edge areas keep the overall structure stable and durable. Notably, there are voids 920 that are not formed below any sensor 908, in this specific non-limiting example the two outermost voids (the first voids on both sides of the pad), and therefore they do not share this varying profile but instead maintain a uniform lower height throughout. The existence of the voids 920 also when they are not below sensors 908 allows the entire pad 902 to bend around the wrist of the subject. The gaps between the wristband-engaging portions 977 formed by the voids 920 allow this bend and the thin portions of the pliable material forming the pliable pad 902 below each sensor 908 yields the sensitivity to pressure applied on the sensors 908, and the combination of these two features yields the suitability of the device 900 to the subtle pressure changes of the skin of the subject caused by the pulse wave passing through the blood vessels below the skin.

[0269] Fig. 9E specifically illustrates a cross-sectional bottom view of the pliable pad 902, clearly showing the varying height profiles of the voids 920. This cross-sectional view particularly exemplifies the distinction between the deeper middle sections 924 and the shallower edge sections 922 of each void. The profile of these voids is essential to the functionality of all embodiments described in Fig. 10 and Fig.ll, as it enables the optimal flexibility characteristics required for accurate physiological measurements regardless of the sensor type employed.

[0270] As a result, the cut-out sections create a ribbed structure of two or more ribs 926 spaced apart by one or more voids. This structure allows the outer portions of the ribs to move away from one another when the pad bends around the wrist. When fited on a wristband WB, the device 900 is capable of moving along different positions of the wristband WB. This configuration enables freedom of movement of the device along the wrist and allows it to be placed in a desired location along the wrist of the subject wearing the device.

[0271] Reference is now made to Figs. 10A-10B, which are schematic illustrations of different views of another embodiment of the device for measuring a physiological parameter. Similar to the previously described embodiment, the device comprises a pliable pad 1002 connected to a base 1010 with the same structural features including the voids 1020 with varying height profiles. Therefore, the embodiment exemplified in Figs. 10A-10B differs from that of Figs. 9A-9F by comprising three PPG (photoplethysmography), light-based sensing arrangements 1009 positioned along the pad axis PA on the wrist-bearing surface 1015, replacing the strain gauge sensors of Figs. 9A-9E.. Each light-based sensing arrangement 1009 includes a light source configured to emit light at a defined wavelength and a light detector configured to detect the signal response. These PPG sensors are capable of detecting blood volume changes, providing direct measurement of blood flow profiles.

[0272] Reference is now made to Figs. 11A-11C, which are schematic illustrations of different views of another embodiment of the device for measuring a physiological parameter. The embodiment exemplified in Figs. 11A-11C differs from that of Figs. 9A- 9F by incorporating a hybrid configuration that comprises both strain gauge sensors 1108 and light-based sensors 1109 on the wrist-bearing surface 1115. Similarly to the embodiment of Figs. 9A-9E, the strain gauge sensors 1108 are arranged along the pad axis PA. Each light-based sensors 1109 is positioned between two adjacent strain gauge sensors 1130 and comprises a light source member 1142 and a light detector member 1144. The light source member 1142 and the light detector member are arranged along a light-based sensor axes SA (parallel to each other) that are defined perpendicular to the pad axis PA on the wrist-bearing plane WBPL (which is a curved plane in this example) defined by the wrist-bearing surface 1115. The light source member 1142 and the light detector member 1144 are spaced apart at an operative distance, which may be defined based on the operative wavelength of the light source member 1142 or dictated by structural constraints. In this specific example, one of the members is located at a first half of the pliable pad 1102 and the other member (light source or detector) is positioned at a second half of the pliable pad 1102, wherein the first and second halves are defined based on the middle distance between a first side 1174 and a second side 1176 of the pliable pad 1102 along the light-based sensor axes SA It is to be noted that the light source members 1142 can be configured to transmit two different wavelengths, e.g. by including two different light sources, and the light detector members 1144 can be configured to detect the response of said two different wavelengths for enhanced physiological measurements. The complementary sensor types allow for simultaneous mechanical (strain) and optical measurements of cardiovascular activity.

[0273] Furthermore, this embodiment of Figs. 11A-11C differs from that of Figs. 9A-9E by further comprising ECG (electrocardiogram) electrodes positioned on the device. Two first electrodes 1189 located on a wrist-facing face 1182 of the wristband-receiving portions 1179 of the base 1110 allowing a first contact of these two electrodes 1189 with a portion of the wrist of the subject when the device 1100 is worn on that wrist. A second electrode 1193 is positioned on an external face 1183 ofthe body portion 1180 ofthe base 1110 facing away from the wrist. The second electrode 1193 serves to allow a second contact, e.g. by placing on it a finger of the opposite hand that is different than that wearing the device. . By forming contacts with these ECG electrodes, the first contacts are constant when the device is worn and the second contact is performed on demand, it enables the device to record the electrical activity of the heart. The combination of strain gauges, PPG sensors, and ECG electrodes in this configuration provides comprehensive cardiovascular monitoring capabilities, allowing for correlation between mechanical pulse waves, optical blood flow measurements, and electrical heart signals for advanced physiological analysis.

Claims

CLAIMS:

1. A device for measuring a physiological parameter, comprising: a pliable pad having a pliable or flexible wrist-bearing surface and configured for placing against a portion of the wrist; and one or more sensors disposed on, within or associated with said pliable pad for sensing at least one of (i) change of pressure on the pad, (ii) deformation of the wristbearing surface, (iii) change of pressure applied on said one or more sensors or, (iv) deformation of said one or more sensors, and for issuing an output signal corresponding thereto indicative of said physiological parameter or a change thereof.

2. The device of claim 1, wherein the one or more sensors comprise one or more strain gauge sensors.

3. The device of claim 1 or 2, wherein the one or more sensors comprise one or more light-based sensing arrangements, each of which comprises: a light source member configured to emit light at a defined wavelength; a light detector member configured to detect response to illumination at said defined wavelength.

4. The device of claim 3, wherein said one or more light-based sensing arrangements are PPG sensors.

5. The device of claim 3 or 4, wherein the one or more sensors further comprise two or more strain gauge sensors spaced apart from one another; at least one intermediate element is positioned between two strain gauge sensors; and wherein said intermediate element is the light source member or the light detector member of at least one of said one or more light-based sensing arrangements.

6. The device of claim 5, wherein said pliable pad extends along a pad axis defined between first and second ends of the wrist-bearing surface; wherein the two or more strain gauge sensors are spaced-apart along said pad axis.

7. The device of claim 5 or 6, wherein the intermediate element and its respective member are aligned along a light-based sensor axis on the wrist-bearing surface normal to said pad axis.

8. The device of any of claims 1 -7, wherein the pliable pad has one or more structure elements formed in a portion of the pad that does not include the wrist-bearing surfaceand having each an outer face, the outer faces of all the structure elements jointly define a base surface that is opposite the wrist-bearing surface, the base surface has one or more discontinuities defined by one or more voids between said elements.

9. The device of claim 8, wherein the discontinuities are grooves that extend between opposite sides of the pad in a direction normal to a pad axis defined between first and second ends of the pliable pad.

10. The device of claim 8 or 9, wherein the structure elements are two or more ribs spaced-apart by one or more voids.

11. The device of claim 10, wherein the ribs extend between opposite sides of the pad in a direction normal to the pad axis.

12. The device of claim 11, wherein at least one of said void extends between a first side and a second of said opposite sides of the pad; said at least one void defines two first sections and a second section, each of the first sections extends between a respective side of said opposite sides and the second section; wherein the second section extends to a greater extent along a vertical axis than the first sections; wherein said vertical axis is defined normal to a plane defined by the opposite surface.

13. The device of claim 11, wherein at least one of the voids, extending between said base surface and an inner end of the void, has at least one deeper inner end portion that is closer to the wrist-bearing surface than other portions of the inner end.

14. The device of claim 13, wherein said deeper inner portion is located opposite one of said one or more sensors.

15. The device of claim 13 or 14, wherein the at least one of the voids comprise two first sections flanking a second section, the inner end of the second portion is closer to the wrist-bearing surface than that of the two first sections.

16. The device of claim 15, wherein the second section is located opposite one of said one or more sensors along said vertical axis.

17. The device of claim 16, wherein the voids have a width which is greater in said second section than in said the first sections.

18. The device of claim 16 or 17, wherein the inner end of the second section has a general shape corresponding to that of said one of said one or more sensors.

19. The device of any one of claims 1-18, wherein the pliable pad is made of a pliable, flexible or elastomeric material.

20. The device of any one of claims 1-19, wherein the pliable pad is made of silicone- based material.

21. The device of any one of claims 1-20, wherein said one or more sensors are attached to or fitted on said wrist-bearing surface.

22. The device of any one of claims 1-21, wherein the pliable pad is fitted on or is configured for fitting on a wrist-facing side of a wrist-fitting element.

23. The device of any one of claims 1-22 comprising: a coupling member attached to or fitted over a wrist-fitting element that extends around the wrist or a portion thereof along an element axis or configured for such attachment or fitting; and wherein said pliable pad (i) being attached to said coupling member, and (ii) extending along a pad axis parallel to said element axis.

24. The device of claim 23, wherein said coupling member comprises two fitting portions extending from a body portion, each fitting portion having an opening for fitting around the wrist-fitting element.

25. The device of claim 24, wherein each of the fitting portions comprises a wristfacing face; wherein one or both of the wrist-facing faces comprises a first ECG electrode.

26. The device of claim 25, wherein the body comprises an external face and a vertical axis is defined normal to said external face; wherein the one or more sensors are disposed at a greater extent from the external face than the wrist-facing faces along said vertical axis in a wrist direction.

27. The device of any one of claims 24-26, wherein the body portion comprises an external face that comprises one or more second ECG electrodes.

28. The device of any one of claims 24-27, wherein the body portion, when being fitted or attached to the wristband, is entirely positioned at an outer side of the wristband, the outer side is being further away from the wrist than an inner side of the wristband.

29. The device of any one of claims 24-28, wherein the pliable pad is attached to the wristband fitting portions.

30. The device of any one of claims 23-29, wherein the pliable pad comprises wristband-bearing portions bearing against the wristband when it is attached to or fitted to the wristband.

31. The device of claim 30, wherein said wristband-bearing portions are defined by a base surface opposite the wrist-bearing surface.

32. The device of claim 31, wherein the coupling member is made of silicone-based material.

33. The device of claim 32, wherein the pliable pad is more pliable or flexible with respect to the coupling member.

34. A device for measuring a physiological parameter, comprising: a pliable pad with a pliable wrist-bearing surface configured for placing against a portion of the wrist and a base opposite thereto, the base being configured to permit the wrist-bearing surface to fit the contours of the wrist; and one or more sensors disposed on, within or associated with said pad for sensing at least one of (i) change of pressure on the pad, (ii) deformation of the wrist-bearing surface, (iii) change of pressure applied on said one or more sensors or, (iv) deformation of said one or more sensors, and for issuing an output signal corresponding thereto indicative of said physiological parameter or a change thereof.

35. The device of any one of claims 1-34, wherein said pliable pad is integrally formed on said wrist band.

36. The device of any one of claims 1-35, comprising an electronic utility for receiving and processing said output signal and for emitting a data signal based thereon.

37. The device of any one of claims 1-36, wherein the physiological parameter is a cardiovascular parameter.

38. The device of any one of claims 1-37, wherein said wrist-bearing surface has a varying pliability between a central portion thereof towards its periphery.

39. A method for measuring a physiological parameter from a skin portion of a subject, comprising: contacting, directly or indirectly, the contact surface of a sensor device according to any one of claims 1-38; and outputting said output signal.

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