A capacitive pulse wave sensor, wearable pulse wave detection device

Abstract

The present application relates to a kind of capacitive pulse wave sensors, wearable pulse wave detection device, including multiple sensor units, each sensor unit is provided with flexible multifunctional layer, the inside of each multifunctional layer is provided with curved surface elastic upper electrode, the lower side of upper electrode is provided with flexible support layer, the top surface of flexible support layer is provided with lower electrode, insulation layer is arranged between upper electrode and lower electrode and forms different capacitances to reflect the component of force in different directions, flexible multifunctional layer is deformed by external force and drives upper electrode to change the contact area with insulation layer, the number of at least one of upper electrode and lower electrode is at least two;Flexible support layer is provided with fiber artificial muscle actuator inside, actuator has telescopic capacity in the direction towards upper electrode, circuit board is arranged below actuator, flexible support layer is fixed to circuit board and is provided with electrical conduction path to electrically connect lower electrode and circuit board, upper electrode is electrically connected with circuit board.

Description

Technical Field

[0001] This invention relates to a capacitive pulse sensor and a wearable pulse detection device. Background Technology

[0002] Pulse diagnosis, one of the four diagnostic methods in Traditional Chinese Medicine (TCM), is a key challenge in achieving objectivity in diagnosis. The objectification and standardization of pulse diagnosis are crucial for the inheritance and development of TCM, while pulse sensor technology represents a bottleneck in this process. TCM pulse diagnosis relies on the practitioner's fingers to perceive changes in the pulse at the wrist, particularly at the guan, cun, and chi points. This pulse is categorized into twenty-eight types, and these changes can be summarized as sensing changes in blood pressure at these points.

[0003] The technological development of pulse sensors can be divided into three stages: 1. In the 1970s and 1980s, single-point rigid surface pressure sensors and single-head sensors appeared. However, single-probe pulse analyzers could not simultaneously collect pulse information from the cun, guan, and chi positions, and there was a problem of repeatedly trying to find the correct guan pulse. In addition, single-point rigid surface pressure sensors did not conform to human touch in terms of bionics, and the pulse information collected was relatively singular. 2. At the end of the 20th century, three-head sensors appeared that could simultaneously collect pulse information from the cun, guan, and chi positions, and could also collect pulse information from a single position within the cun, guan, and chi positions. Manual vertical adjustment screws and manual radial adjustment screws were designed to achieve the displacement of the sensor in the radial and vertical directions of the radial artery. 3. Since the 21st century, the development of pulse analyzers has mainly focused on the following three points: ① Designing ordinary array pressure sensors to collect pulse information at multiple points; ② Designing flexible array pressure sensors that can mimic human touch in terms of bionics; ③ Constructing a composite acquisition mode that coordinates pressure sensors with non-contact sensors such as photoelectric sensors and microphones to collect pulse information.

[0004] Two major shortcomings of current pulse sensor technology lie in the precise control of pressure applied by TCM experts' fingers and the sensitivity of pressure detection (i.e., the ability to distinguish force).

[0005] The pressure regulating devices or actuators used to simulate the pressure applied by a traditional Chinese medicine expert's fingers are basically implemented by electric motors or pneumatic devices. For example, CN107847164B uses a fluid or air bladder, and CN201980023078 uses an air bladder. Electric motors or pneumatic devices are bulky and cannot compare with the dexterity of human fingers, resulting in low efficiency in pulse diagnosis. At the same time, it is difficult to achieve precise pressure changes in coordination with detection data, and thus cannot achieve the precise control of pressure applied by a traditional Chinese medicine expert's fingers.

[0006] On the other hand, Professor Leng Jinsong's team at Harbin Institute of Technology discovered that by functionalizing polyelectrolytes, the "bipolar" actuation of artificial muscle smart materials can be transformed into "unipolar" actuation. They also discovered the anomalous phenomenon that the actuation performance of artificial muscles increases as capacitance decreases (Scan Rate Enhanced Stroke, SRES). Furthermore, they developed carbon nanotube fiber artificial muscles with unipolar stroke and electroosmotic pump. Compared with traditional artificial muscles, these artificial muscles have the characteristics of being non-toxic, having a high actuation frequency (up to 10Hz), low actuation voltage (1V), high specific energy (0.73-3.5J / g), high actuation strain (3.85-18.6%), and high energy density (up to 8.17W / g). They have great application potential in fields such as space deployment structures, biomimetic flapping-wing aircraft, deformable aircraft, underwater robots, flexible robots, wearable exoskeletons, and medical robots.

[0007] In terms of pressure detection sensitivity, the detection capability of a human hand, as measured by a traditional Chinese medicine expert, can reach an average normal pressure threshold of 0.055g for male fingertips and 0.019g for female fingertips. This is something that tactile sensors in electronic skin based on traditional pulse sensors can hardly match.

[0008] The flexible capacitive three-dimensional force vector sensor structure disclosed in patent CN201920633712.5, through the upper electrode of the multifunctional layer and the lower electrode array, can achieve the functional requirements of tactile sensation (when the sensing system is about to or has just come into contact with an external object, it should be able to roughly classify the external object that is about to or has just come into contact with it and judge the speed and distance of the approaching external object) and sensing the magnitude and direction of three-dimensional force (XYZ), while taking into account the requirements of high sensitivity, wide detection range and flexible contact. In the test, the sensor unit can achieve a normal force (pressure direction, Z direction) resolution of 0.01 grams, which surpasses the pressure resolution ability of the fingers of traditional Chinese medicine experts (0.019 grams), and can be said to have an inherent advantage in the construction of tactile sensors in pulse sensor technology.

[0009] Therefore, the problem this patent proposal aims to solve is how to organically integrate the two technologies into a very small space due to the trend of miniaturization of pulse sensors, so as to achieve precise control capabilities and pressure detection sensitivity comparable to the finger pressure applied by a TCM expert, while taking into account the wiring difficulties caused by the large number of electrodes. Summary of the Invention

[0010] To address the shortcomings of existing technologies, a capacitive pulse sensor is proposed, comprising at least two sensor units, each with a flexible multifunctional layer. Each multifunctional layer contains an upper electrode electrically connected to it, and the upper electrode is a curved elastic electrode. A flexible support layer is positioned below the upper electrode, and a lower electrode is positioned on the top surface of the flexible support layer. An insulating layer is positioned between the upper and lower electrodes, and the downward projection of the upper electrode at least covers a portion of the area of ​​each lower electrode. When the flexible multifunctional layer deforms under external force, the contact area between the upper electrode and the insulating layer changes. At least one of the upper and lower electrodes has at least two electrodes, and different capacitances are formed between the upper and lower electrodes to reflect the force components in different directions. A fiber artificial muscle actuator is disposed within the flexible support layer, possessing telescopic capability in the direction towards the upper electrode. A circuit board electrically connected to the actuator is positioned below it. The flexible support layer is fixed to the circuit board and has an electrical conduction path connecting the lower electrode to the circuit board, while the upper electrode is electrically connected to the circuit board.

[0011] The structure of this invention can reflect the force components in different directions based on the deformation of the flexible multifunctional layer of the flexible sensor unit and the different capacitances formed between the upper and lower electrodes, achieving pressure resolution capabilities (normal and Z-direction) that meet or exceed those of a human finger. The pressure control structure of the electrically actuated fabric fiber artificial muscle matrix achieves low-voltage, low-power pressure matrix control. Combined with the flexible sensor unit matrix, when the artificial muscle is actuated, the lower electrode can deform to transmit the actuation, achieving coordinated pressure control for precise alignment of the superficial, middle, and deep pulses, as well as precise local pressure control of arterial vessels, resulting in accurate and continuous blood pressure detection. The lightweight fabric fiber artificial muscle actuator facilitates the development of wearable pulse detection devices. Through the structural coordination of the upper electrode, flexible support layer, lower electrode, actuator, and circuit board, while achieving precise pressure application and detection by the actuator driving the flexible multifunctional layer, the required space is optimized to the greatest extent, solving the wiring problem caused by a large number of electrodes and meeting the miniaturization requirements of pulse sensors.

[0012] As an example, the blood flow velocity in the human body is <20mm / s. Based on the aforementioned tactile sensor structure, and using a high-conversion-rate chip with a conversion rate of over 0.5ms to acquire capacitance values ​​from each electrode, 20 / 2000 = 0.01mm / ms. In other words, it can achieve a normal force resolution of 0.01 grams, surpassing the pressure discrimination capability of a traditional Chinese medicine expert's fingers (0.02 grams). The high-conversion-rate chip can be, for example, the R-SpiNNaker chip, which achieves a 24-bit high-speed CDC, an effective resolution of 21.9 bits, and a conversion time of 0.5ms, supporting high-precision tactile signal acquisition and encoding. The function kernel + SNN kernel architecture uses a small number of neurons to support complex pseudo-neural computation, enabling real-time single-chip pulse classification. The pseudo-neural perception, computation, and execution integrated architecture allows a single chip to support high-precision pulse pressure control and pulse classification data processing. For details, please refer to patent document CN202110956246.6.

[0013] In this invention, the upper electrode can be used as a common electrode, and the lower electrode has at least two electrodes that are insulated from each other. The common electrode forms different capacitances to each lower electrode to reflect the force components in different directions. Alternatively, the lower electrode can be used as a common electrode, and the upper electrode has at least two electrodes that are insulated from each other. The common electrode forms different capacitances to each upper electrode to reflect the force components in different directions.

[0014] Furthermore, the circuit board can be a rigid PCB or a flexible PCB, with the latter being preferred to give the pulse sensor in wearable pulse detection devices such as watches superior biomimetic performance. The top surface of the flexible support layer is curved or flat.

[0015] As an improvement, the circuit board can be configured as two electrically connected layers, with the lower circuit board located below the actuator and the upper circuit board located below the flexible multifunctional layer. The upper circuit board has clearance holes aligned with the flexible support layer, allowing the flexible support layer to pass through. The upper electrode is electrically connected to the upper circuit board via the flexible multifunctional layer. In this improvement, the lower electrode is connected to the lower circuit board via the flexible support layer, and the upper electrode is connected to the upper circuit board via the flexible multifunctional layer. The electrical connection between the upper and lower circuit boards maximizes the optimization of the wiring structure, reduces wiring difficulty, achieves reliable multi-electrode connection under miniaturization conditions, and reduces detection interference caused by the circuitry. More preferably, the capacitive pulse sensor can also include an artificial muscle positioning block. The artificial muscle positioning block has a receiving groove, and the flexible support layer and actuator are positioned and supported within the receiving groove. In this case, the lower circuit board is fixed to the bottom surface of the artificial muscle positioning block, and the upper circuit board is fixed to the top surface of the artificial muscle positioning block, improving the overall structural stability.

[0016] Furthermore, the flexible support layer and the lower electrode are integrally formed by two-color molding of a flexible insulator and a flexible conductor, wherein the insulator separates the conductor into the lower electrode, and the bottom of the lower electrode extends downward to be electrically connected to the circuit board below the actuator.

[0017] Human arteries are tubular structures, and blood flow within them is cyclical. With the direction of blood flow as the X-axis, pressure changes are reflected in the Z-axis (normal) bulges on the arterial walls caused by blood pumping by the heart. The X-axis reflects the direction of blood flow, while the Y-axis reflects the thickness of the blood vessels. For blood pressure monitoring, pressure changes are more important, while flow direction and vessel thickness serve as supplementary information.

[0018] As an alternative improvement, the flexible multifunctional layer can be configured with the following structure:

[0019] (1) Includes a first flexible multifunctional layer in the shape of a sphere or an ellipsoid, wherein at least one of the upper and lower electrodes below the first flexible multifunctional layer is at least three, for example, the upper electrode is a common electrode and the lower electrode forms a matrix, thereby enabling the XYZ direction resolution capability of force.

[0020] (2) Includes a strip-shaped second flexible multifunctional layer. At least one of the upper and lower electrodes below the second flexible multifunctional layer has at least two electrodes, and each electrode is distributed on both sides of the strip of the second flexible multifunctional layer. The second flexible multifunctional layer, when deformed radially by force, can cause the upper electrode to change its contact area with the insulating layer. For example, the upper electrode can serve as a common electrode, and the lower electrode consists of two electrodes distributed on both sides of the dashed line A, which is distributed along the X-direction. In this case, the tactile sensor can obtain not only Z-direction force resolution but also Y-direction resolution. Simultaneously, due to the reduced number of electrodes, the channel distribution pressure and cost reduction are advantages. Alternatively, the dashed line A can be distributed along the Y-direction to obtain X-direction resolution. The above describes the case where the strip of the second flexible multifunctional layer extends in the same direction. Regarding the strip extension direction... In different scenarios, such as the upper electrode serving as a common electrode, each sensor unit has two lower electrodes. Some sensor units have their lower electrodes distributed on both sides of dashed line A, while others have them distributed on both sides of dashed line B. One of dashed lines A and B is set along the X-axis of the coordinate system, while the other is tilted or perpendicular to the X-axis. This achieves high resolution in the XYZ directions, and each node in the array has Z-axis resolution capability. Furthermore, the number of electrode matrices is reduced from four to two, maximizing the reduction in the number of channels required for the entire array and achieving optimal cost control. Moreover, one of dashed lines A and B can be set along the X-axis of the coordinate system, while the other is set along the Y-axis, making them perpendicular. In addition to both having Z-axis detection capability, one is used to acquire X-axis data and the other is used to acquire Y-axis data without interfering with each other.

[0021] (3) It can also include the sum of the above two schemes (1) and (2). For example, the sensor array includes at least one first sensor unit and at least one second sensor unit; each first sensor unit is provided with a spherical or ellipsoidal first flexible multifunctional layer, and each second sensor unit is provided with a second flexible multifunctional layer. In the first sensor unit, at least one of its upper and lower electrodes has at least three electrodes, and in the second sensor unit, at least one of its upper and lower electrodes has at least two electrodes. At this time, the first sensor unit can achieve high resolution in the XYZ direction, and the second sensor unit has at least high resolution in the Z direction. The array formed by the two facilitates the alignment of the caliper and pressure detection. At the same time, the number of electrode matrices of the second sensor unit is reduced from four to two, and the number of channels required for the entire array is greatly reduced, and the cost is controllable. In scheme (3), the first sensor unit and the second sensor unit in each row and column of the array can be alternately arranged. Since the blood vessel is strip-shaped, the alternating arrangement can ensure that at least one of its adjacent second sensor units also makes contact with the blood vessel when the first sensor unit contacts the blood vessel.

[0022] As another improvement, the sensor can also incorporate an association structure, which is a flexible material and connects the flexible multifunctional layers of each sensor unit. This association connects the force applied to any area of ​​the pulse sensor surface to the flexible multifunctional layers of at least two sensor units closest to the force application point. By incorporating this association structure on the flexible multifunctional layers of each sensor unit, any force applied to the surface of the association structure will be associated with the surrounding unit packages. The location of the force application point can be calculated using data from the surrounding unit packages, thus resolving detection blind spots. More preferably, the association structure can be a flexible coating. In this scheme, the outer surface of the flexible multifunctional layers of each sensor unit is skinned by the flexible coating. When the surface of the association structure is subjected to force, the flexible coating pulls the surrounding unit packages to achieve force association, improving motion interference and noise reduction. Alternatively, the association structure can be a flexible filler, filling the spaces between the flexible multifunctional layers of any sensor unit. In this case, when the surface of the association structure is subjected to force, the flexible filler pushes the surrounding unit packages to achieve force association. These two schemes can also be combined, simultaneously incorporating a flexible coating and a flexible filler, achieving association and constraint through a push-pull combination. Furthermore, the association structure can be made insulating or conductive. In one scenario, the associated structure is insulated, meaning the flexible multifunctional layers of each sensor unit are insulated from each other. The flexible multifunctional layers serve as electrodes, and the combination of these electrodes enables tactile detection. Alternatively, the flexible multifunctional layers of each sensor unit are electrically conductive, with the associated structure acting as a protective layer. In another scenario, the associated structure is conductive, insulated from the flexible multifunctional layers of each sensor unit, and acts as a shielding electrode. Alternatively, the associated structure is electrically connected to the flexible multifunctional layers of each sensor unit. In this case, the associated structure and the flexible multifunctional layers can be integrally formed or electrically connected via conductive components such as conductive adhesive.

[0023] As another improvement, the flexible multifunctional layer and the upper electrode are integrated. Based on the formation of capacitor combinations with different vector directions, the flexible multifunctional layer can be spherical, ellipsoidal, or strip-shaped. A spherical or ellipsoidal shape of the flexible multifunctional layer achieves good deformation under stress in the XYZ directions, while a strip shape affects the deformation under stress in the strip's extension direction. The optimal choice for the upper electrode is to form the same shape as the flexible multifunctional layer. For example, when the flexible multifunctional layer is spherical or ellipsoidal, the upper electrode can also be spherical or ellipsoidal to achieve optimal resolution; alternatively, when the flexible multifunctional layer is strip-shaped, the upper electrode can be a parallel strip shape.

[0024] A wearable pulse detection device is also provided, including the capacitive pulse sensor described above. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a capacitive pulse sensor and a wearable pulse detection device.

[0026] Figure 2 This is a schematic diagram of a capacitive pulse sensor and a wearable pulse detection device.

[0027] Figure 3 This is a schematic diagram of a capacitive pulse sensor and a wearable pulse detection device in a flattened state.

[0028] Figure 4 This is an exploded view of the structure of a capacitive pulse sensor and a wearable pulse detection device.

[0029] Figure 5 This is a schematic diagram of the lower electrode unit structure of a capacitive pulse sensor.

[0030] Figure 6 This is a schematic diagram of the upper and lower electrode distribution of a capacitive pulse sensor unit.

[0031] Figure 7 This is a schematic diagram illustrating the cross-sectional structure of a capacitive pulse sensor.

[0032] Figure 8 This is a schematic diagram illustrating the operation of an artificial muscle using a capacitive pulse sensor. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] like Figure 1 As shown, this embodiment provides a capacitive pulse wave sensor and a wearable pulse wave detection device. The detection device includes a capacitive pulse wave sensor 10 and a wearable wristband 20 with a display. Figure 2 When this device is worn on the wrist, the pulse sensor's sensing area can completely cover and closely adhere to the pulse area of ​​the wrist at the cun, guan, and chi positions.

[0035] like Figure 3 As shown, the capacitive pulse sensor is made entirely of flexible material and can be laid flat when the pulse detection device is not worn. Figure 4 As shown, the capacitive pulse sensor includes: an upper electrode multifunctional layer 100, which is made of conductive silicone and molded; a lower electrode assembly 200, which is made of insulating silicone and conductive silicone in a dual-color mold; an FPC flexible circuit board 400; a flexible positioning block 500, which is made of conductive silicone and molded; a CDC and control chip 600; and a flexible wrist 700.

[0036] like Figure 5As shown, electrode unit 201 in the lower electrode group is molded using a two-color mold of insulating and conductive silicone. The surface is then coated with insulating varnish. Insulating cross-shaped electrode 201-5 divides the conductive silicone into four electrodes: 201-1, 201-2, 20-3, and 201-4. Figure 6 As shown, a sensing unit 101 in the upper common electrode layer is a circular sac. It forms capacitors C1-1, C1-2, C1-3, and C1-4 with the electrode unit arrays 201-1, 201-2, 201-3, and 201-4 in the lower electrode group, respectively. The outer hemispherical convex surface receives forces from different directions. The inner hemisphere is tangent to the surface of the lower electrode unit. Theoretically, the hemisphere of the upper electrode and the insulating varnish on the surface of the lower electrode unit are in point contact, and the contact point is exactly at the center of the electrode group 201. When the outer surface is subjected to the pressure 800 of the wrist pulse, the flexible upper electrode deforms. The hemisphere of the upper electrode and the insulating ink on the PCB surface can easily change from point contact to small-area contact, thereby causing a change in the C1 capacitor group and sensing the wrist pulse.

[0037] like Figure 7 As shown in the cross-sectional diagram, artificial muscle units 301 are placed inside the lower electrode unit 201, and they are fixed in the through holes of the positioning block 500. The lower electrode passes through the through holes of the positioning block and the flexible circuit board to contact the upper electrode. Figure 8 As shown, when a voltage is applied to the artificial muscle unit, the artificial muscle will deform and elongate, pushing the lower electrode unit and the upper electrode to locally elongate and protrude to apply pressure to the wrist, simulating the different degrees of pressure applied by the fingers of traditional Chinese medicine to the pulse, achieving the purpose of controlling the pressure of floating, middle and deep pulses, thereby realizing the measurement of complex pulse changes.

[0038] like Figure 4 As shown, since a single sensor unit has four lower electrodes (201-1, 201-2, 20-3, and 201-4) plus an upper electrode that need to be electrically connected, to solve the wiring problem, the FPC flexible circuit board 400 is set up as two layers with side electrical connections. The lower circuit board is located below the artificial muscle unit 301, and the upper circuit board is located below the flexible multifunctional layer 100. The upper circuit board has clearance holes aligned with the flexible support layer. In terms of electrical connection, the upper electrode is electrically connected to the upper circuit board through the flexible multifunctional layer. The artificial muscle unit 301 and the lower electrodes 201-1, 201-2, 20-3, and 201-4 are connected to the lower circuit board through their bottoms.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A capacitive pulse sensor, characterized in that: It includes at least two sensor units forming a dot matrix, each sensor unit having a flexible multifunctional layer, and each multifunctional layer having an upper electrode electrically connected to the multifunctional layer inside, the upper electrode being a curved elastic electrode; A flexible support layer is provided below the upper electrode, and a lower electrode is provided on the top surface of the flexible support layer. An insulating layer is provided between the upper electrode and the lower electrode, and the downward projection of the upper electrode covers at least a portion of the area of ​​each lower electrode. The flexible multifunctional layer is deformed by external force, causing the upper electrode to change the contact area with the insulating layer. At least one of the upper electrode and the lower electrode has at least two components. Different capacitances are formed between the upper electrode and the lower electrode to reflect the components of the force in different directions. The flexible support layer contains a fiber artificial muscle actuator. The actuator has the ability to extend and retract in the direction towards the upper electrode. A circuit board electrically connected to the actuator is located below it. The flexible support layer is fixed to the circuit board and has an electrical conduction path to connect the lower electrode to the circuit board. The flexible support layer and the lower electrode are formed as one piece by a flexible insulator and a flexible conductor in two colors. The insulator separates the conductor into the lower electrode. The bottom of the lower electrode extends downward to connect electrically with the circuit board below the actuator. The upper electrode is electrically connected to the circuit board, which is a rigid PCB or an FPCB.

2. The capacitive pulse sensor according to claim 1, characterized in that, The method by which the upper electrode is electrically connected to the circuit board further includes: The circuit board has two electrically connected layers, upper and lower. The lower circuit board is located below the actuator, and the upper circuit board is located below the flexible multifunctional layer. The upper circuit board has a clearance hole that allows the flexible support layer to pass through, and the upper electrode is electrically connected to the upper circuit board through the flexible multifunctional layer.

3. The capacitive pulse sensor according to claim 2, characterized in that: It also includes an artificial muscle positioning block, which has a receiving groove. The flexible support layer and actuator are disposed in the receiving groove. The lower circuit board is fixed to the bottom surface of the artificial muscle positioning block, and the upper circuit board is fixed to the top surface of the artificial muscle positioning block.

4. The capacitive pulse sensor according to claim 1, characterized in that: The top surface of the flexible support layer is either curved or flat.

5. The capacitive pulse sensor according to claim 1, characterized in that: The flexible multifunctional layer includes a spherical or ellipsoidal first flexible multifunctional layer, and at least one of the upper and lower electrodes below the first flexible multifunctional layer has at least three electrodes; and / or The flexible multifunctional layer includes a strip-shaped second flexible multifunctional layer. At least one of the upper and lower electrodes below the second flexible multifunctional layer has at least two electrodes, and each electrode is distributed on both sides of the strip of the second flexible multifunctional layer. When the second flexible multifunctional layer is deformed by force in the radial direction of its strip, it can cause the upper electrode to change the contact area with the insulating layer.

6. The capacitive pulse sensor according to claim 5, characterized in that: The elongated directions of each of the second flexible multifunctional layers may be the same or different.

7. The capacitive pulse sensor according to claim 1, characterized in that: It also includes an association organization, which is a flexible material and a flexible multifunctional layer connecting each sensor unit, for associating the force on any area of ​​the surface of the capacitive pulse sensor with the flexible multifunctional layer of at least two sensor units closest to the force point.

8. The capacitive pulse sensor according to claim 7, characterized in that: The associated tissue is a flexible membrane, and the outer surface of the flexible multifunctional layer of each sensor unit is skinned by the flexible membrane; and / or The associated tissue is a flexible filler and is filled between the flexible multifunctional layers of any of the sensor units.

9. A wearable pulse detection device, characterized in that: Including the capacitive pulse sensor as described in any one of claims 1-8.

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