Self-driven multifunctional sensor for wrist joint of artificial hand

Abstract

The invention discloses a self-driven multifunctional sensor for an artificial hand wrist. An angle-speed detection mechanism and a pulse measuring ring are integrated; the angle detection mechanism is composed of a first rotor disc, a fixed stator disc and a friction layer, the first rotor disc and the fixed stator disc can rotate relatively, and sine electric signals corresponding to angle changes are output when the wrist bends and stretches based on the friction electrification effect. The speed detection mechanism generates a characteristic cycle electric signal related to the rotating speed through friction between a second rotor disc and a fixed electrode disc with a specific electrode; the pulse measuring ring is integrated on the inner side of the watchband, and the built-in flexible piezoelectric sensing module is tightly attached to the radial artery of the wrist, so that pulse fluctuation can be directly detected; the whole device does not need an external power supply, can generate sensing signals in a self-driven mode through mechanical friction and pulse pressure, and synchronously achieves simultaneous measurement of the wrist angle, the rotating speed and the pulse signals by means of a four-channel high-speed electrical measuring instrument and a multi-channel serial port circuit.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more specifically to a self-driven multifunctional sensor for a prosthetic wrist joint. Background Technology

[0002] Current human prostheses, especially prosthetic hands, urgently need to improve their bionic interaction capabilities. Real-time and accurate perception of wrist joint movement (such as angle and speed) is crucial for achieving natural control and feedback. However, traditional angle and speed sensors (such as encoders and gyroscopes) rely on external power supplies, which not only increases the size, weight, and complexity of the prosthetic system but also significantly affects the convenience and reliability of long-term use by people with disabilities due to battery life limitations and frequent charging issues. Triboelectric nanogenerator (TENG) technology, which can directly convert mechanical energy (such as joint rotation) into electrical signals, provides a revolutionary solution for building self-driven sensors. It can generate signals characterizing motion parameters without an external power supply, greatly simplifying system design.

[0003] However, applying TENG directly to key joints of prosthetic hands (such as the wrist joint) and performing reliable motion sensing faces challenges such as structural integration, stability, and environmental adaptability. Existing related research is mostly focused on laboratory verification or simple models, lacking a stable and reliable self-driven angle and velocity sensor solution specifically designed for the wrist joint that is closely integrated with the actual mechanical structure and application scenarios of prosthetic hands. Summary of the Invention

[0004] The purpose of this invention is to provide a self-driven multifunctional sensor for the wrist joint of a prosthetic hand, so as to solve the problem of the lack of actual mechanical and application scenarios of prosthetic hands in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a self-driven multifunctional sensor for the wrist joint of a prosthetic hand. This sensor innovatively integrates the triple functions of an angle-velocity detection mechanism and a pulse measurement ring, and simultaneously measures signals through different channels of a four-channel high-speed electrophysiological instrument. This enables synchronous self-driven monitoring of wrist joint motion parameters (angle, velocity) and physiological signals (pulse) without the need for external power supply, significantly improving the integration and practicality of the prosthetic system.

[0006] Furthermore, in terms of overall architecture, the sensor adopts a layered design: the angle-velocity detection mechanism at the top works in conjunction with the pulse measurement ring at the bottom, achieving functional complementarity through mechanical structure and circuit integration; the angle-velocity detection mechanism includes an angle sensing module and a velocity sensing module connected coaxially, which are mechanically linked through a drive shaft to ensure the synchronization and consistency of motion parameter acquisition. The overall structure is compact and easy to assemble with the prosthetic wrist joint.

[0007] Furthermore, the angle sensing module adopts a partitioned electrode design. Its stator disk consists of 48 identical sector units, each corresponding to an angle of 6°, spaced 1.5° apart. Odd-numbered sector units are electrically connected at the bottom of the inner ring, while even-numbered sector units are electrically connected at the top of the outer ring, forming independent output paths. The rotor disk is equipped with 24 evenly distributed sector units, which initially correspond one-to-one with the stator units. When the external force drives the rotor to rotate, the rotor copper units periodically sweep across the PTFE friction layer, inducing charge transfer at the stator end through contact electrification. Since the unit ratio is 2:1, a complete sine cycle is generated every time a pair of electrodes is traversed, thereby outputting a continuous sinusoidal AC signal with stable amplitude and frequency proportional to the rotation angle, which facilitates subsequent signal processing and angle calculation.

[0008] Furthermore, the speed sensing module adopts a differentiated electrode layout. The stator disk consists of 72 sector-shaped units, each unit corresponding to an angle of 4° and spaced 1° apart. Every two units of the same size form an electrode pair, and the lengths of adjacent electrode pairs are designed differently. Specifically, it adopts a combination method of 9 pairs of units as a group. The unit lengths are arranged according to the rule of "long-short-long-short-long-short-short-long". The long unit is 10mm long and the short unit is 5mm long. Signal encoding is achieved through this non-uniform arrangement, which facilitates the identification of rotation direction and speed.

[0009] Furthermore, the speed sensing rotor disk is equipped with four pairs of evenly distributed long sector-shaped units. During rotation, the rotor units contact the PI friction layer to generate characteristic electrical signals. Due to the difference in stator electrode length, every nine sets of electrodes rotate, a periodic AC signal sequence of "high-low-high-low-low-low" is output. This signal pattern is related to the direction of rotation (clockwise is the above sequence, and counterclockwise is the reverse feature). At the same time, the signal frequency is linearly related to the rotation speed. One signal cycle corresponds to a rotation angle of 10°. By counting the signal cycles, the real-time rotation speed can be accurately calculated, realizing passive speed detection.

[0010] Furthermore, the pulse measurement ring is integrated inside the watch band, including a flexible sensing module and a baseband structure. The sensing module adopts a multi-layer packaging design: mica is used as a flexible substrate, on which a platinum bottom electrode is sputtered, and then a PZT piezoelectric film is deposited. A platinum top electrode is then prepared on the surface of the film. Finally, the entire sensing element is encapsulated between two PI films to form a "sandwich" structure. Two copper wires are led out from the upper film to connect to the top and bottom electrodes respectively, forming a closed loop to ensure the stability and reliability of the signal output.

[0011] Furthermore, when the pulse measurement ring is in close contact with the radial artery, the arterial pulsation causes periodic deformation of the piezoelectric film. This deformation is converted into changes in charge inside the film, which outputs a millivolt-level voltage signal through the electrode leads. The waveform clearly presents the pulse wave and dicrotic notch characteristics, realizing passive pulse waveform monitoring and providing real-time physiological status feedback for prosthetic users.

[0012] Furthermore, the miniaturized integration solution is the core innovation. The stator / rotor disks of the angle and speed modules are both manufactured using copper-etched PCB boards with a diameter controlled within 30mm, an inner diameter of 5mm, and a PCB board thickness of 1mm. The angle stator disk and the speed stator disk are respectively etched on the front and back sides of the same PCB board. The upper PCB board supports the angle rotor disk, and the lower PCB board supports the speed rotor disk. This multi-layer stacking design greatly saves space and achieves high-density functional integration.

[0013] Furthermore, mechanical compatibility is achieved through three-point fixation. The stator disk is embedded into the joint base through three slots, ensuring that the sensing mechanism remains stably aligned and mechanically aligned during rotation. This design achieves dual-mode motion sensing function integration within a limited space, while facilitating installation and maintenance and improving the robustness of the overall structure.

[0014] Furthermore, signal reliability is ensured through material optimization. The angle module uses a PTFE friction layer to achieve stable sinusoidal signal output, and its high negative charge and wear resistance ensure signal consistency under long-term use. The speed module uses a PI friction layer to ensure the periodicity of characteristic signals, and its flexibility and high temperature resistance are suitable for high-speed rotation scenarios. Both modules achieve contact pressure control through an adjustment mechanism. The adjustment mechanism consists of a top shell and an adjuster, which can finely adjust the clamping force between the rotor and stator to optimize the friction contact state, thereby improving signal quality and sensor lifespan.

[0015] Furthermore, the test structure of the speed sensing module includes a rotor substrate one, a test rotor, a friction layer PTFE, a test stator, and a rotor substrate two.

[0016] Compared with existing technologies, this invention provides a self-driven multifunctional sensor for the wrist joint of a prosthetic hand. It integrates two main functional modules—an angle-velocity detection mechanism and a pulse measurement ring—from top to bottom, constructing a compact bionic sensing system. The angle-velocity detection mechanism employs a coaxial linkage design, integrating the angle and velocity sensing modules onto the same drive shaft. It synchronously acquires the flexion-extension angle and rotational velocity of the wrist joint through the principle of triboelectricity. Angle detection is based on a specific ratio of 24 rotor units to 48 stator units, outputting a stable sinusoidal electrical signal. Velocity detection utilizes a special arrangement of 72 sector-shaped units in the stator to generate a periodic signal with directional characteristics. Meanwhile, the pulse measurement ring integrated inside the strap uses a flexible bonding structure and a PZT piezoelectric film to convert radial artery pulsation into an electrical signal, achieving passive physiological monitoring. The two modules share a signal processing circuit and use a copper-etched PCB board to integrate the two stator disks on the same front and back of the board, realizing the miniaturization and integration of the sensor. Through the coordinated perception of motion and physiological information, the system significantly improves the motion control accuracy of the prosthetic hand, integrates motion feedback and health monitoring functions, and extends the service life of the device by eliminating dependence on external power supply with a fully self-driving mechanism, providing comprehensive motion and health management support for prosthetic users. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the self-driven multi-functional sensor of the prosthetic hand's mechanical wrist joint connected to the prosthetic hand, as disclosed in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a self-driven multifunctional sensor for the prosthetic wrist joint disclosed in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the disassembly structure of the self-driven multifunctional sensor of the prosthetic hand mechanical wrist joint disclosed in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the angle sensing module disclosed in the embodiments of the present invention;

[0022] Figure 5 This is a schematic diagram of the speed sensing module disclosed in the embodiments of the present invention;

[0023] Figure 6 This is a schematic diagram of the angle sensing module disclosed in the embodiments of the present invention;

[0024] Figure 7 This is a schematic diagram of the angle-velocity sensor disclosed in an embodiment of the present invention;

[0025] Figure 8 This is a diagram of the angle sensor signal disclosed in an embodiment of the present invention;

[0026] Figure 9 Channel 4 shows the speed sensor signal variation diagram disclosed in this embodiment of the invention.

[0027] Figure 10 This is a structural diagram of the test scheme disclosed in the embodiments of the present invention;

[0028] Figure 11 This is a diagram of the test stator structure disclosed in an embodiment of the present invention;

[0029] Figure 12 The X-phase signal diagram is shown in the embodiment of the present invention.

[0030] Figure 13 This is a reverse signal diagram of the test scheme X disclosed in the embodiments of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Pulse measurement ring; 2. Angle-velocity detection mechanism; 3. Prosthetic hand; 10. Pulse detection module; 20. Adjustment mechanism; 21. Angle sensing module; 22. Velocity sensing module; 201. Top shell; 202. Regulator; 23. Outer shell; 24. Drive shaft; 211. Upper PCB board; 212. First rotor disk; 213. First friction layer; 214. First stator disk; 215. Middle PCB board; 221. Lower PCB board; 222. Second rotor disk; 223. Second friction layer; 224. Second stator disk; 101. PI film; 102. Pt electrode; 103. PZT film; 401. Rotor substrate one; 402. Test rotor; 403. Friction layer PTFE; 404. Test stator; 405. Rotor substrate two. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] As attached Figure 1 To be continued Figure 13 As shown:

[0035] Example 1:

[0036] A self-driven multifunctional sensor for a prosthetic wrist joint includes an angle sensing module 21, a speed sensing module 22, and a pulse detection module 10. The first rotor disk 212 and the second rotor disk 222 of the angle sensing module 21 and the speed sensing module 22 are coaxial and are driven to rotate by adjustment mechanisms 20 on both sides. The adjustment mechanism 20 includes a top shell 201 and an adjuster 202. The first stator disk 214 and the second stator disk 224 are etched on the front and back sides of the same PCB board 215. The PCB board 215 is embedded in the inner groove of the angle-speed detection mechanism 2. The angle sensing module 21 and the speed sensing module 22 are wrapped by a shell 23. One side of the shell 23 is a protruding end, and the other side of the shell 23 is a concave end. The two shells 23 are connected and wrapped on both sides. The pulse measurement ring 1 is connected to the lower part of the watch strap and the angle-velocity detection mechanism 2. The pulse detection module 10 is attached to the inside of the watch strap. When the watch strap is put on the wrist, the pulse detection module 10 can be closely attached to the upper radial artery of the wrist.

[0037] The angle sensing module 21 has a diameter of 30mm and an inner diameter of 5mm. It includes a first rotor disk 212, a first friction layer 213, and a first stator disk 214, all of which are etched on the upper PCB board 211 and the middle PCB board 215. The upper PCB board 211 and the middle PCB board 215 are both 1mm thick. The first rotor disk 212 consists of 24 copper foil sector units. The angle is set below it by a first stator disk 214 composed of 48 copper pole sector units. The sector unit is 6°, and the interval between every two sector units is 1.5°. The surface of the first stator disk 214 is covered with the first friction layer 213, which is a polytetrafluoroethylene friction layer. The odd-numbered sector units and even-numbered sector units of the first stator disk 214 have independent lead wires.

[0038] Meanwhile, the speed sensing module 22 includes a second rotor disk 222, a second friction layer 223, and a second stator disk 224. The second stator disk 224 is an annular variable amplitude finger electrode, with each pair of electrodes spaced at a fixed angle. In the initial state, the rotor unit and the stator unit are completely aligned.

[0039] Furthermore, when the wrist joint twists, the external force drives the first rotor disk 212 to rotate relative to the first stator disk 214. The rotor copper unit periodically sweeps across the first friction layer 213. Through charge conservation, charge transfer is generated between the adjacent copper electrodes of the first stator disk 214. Due to the 2:1 ratio design of the number of units, an independent layer mode triboelectric nanogenerator is formed. When the rotor rotates, a complete sinusoidal signal cycle is generated every time it slides across a pair of electrodes. The output terminal forms a sinusoidal alternating current signal with stable amplitude. The corresponding angle of wrist rotation can be obtained by the angle between adjacent electrode pairs of the designed copper electrode fan-shaped unit and the number of cycles.

[0040] Correspondingly, the speed sensing module 22 and the angle sensing module 21 share a drive shaft 24, which includes a second rotor disk 222 and a second stator disk 224, both etched on the lower PCB board 221 and the middle PCB board 215. The lower PCB board 221 is 1mm thick. The second stator disk 224 is designed with 72 specially arranged fan-shaped units, each fan-shaped unit is 4°, and every two pairs of fan-shaped units are spaced 1° apart. Every nine pairs of units form an electrode group. The length of the fan-shaped units is arranged according to the rule of long-short-long-short-short-long-short-short-short. The inner ring electrode and the independent electrode lead out wires, where the long fan-shaped unit is 10mm long and the short fan-shaped unit is 5mm long. The second rotor disk 222 is equipped with four evenly distributed long fan-shaped copper units, with a second friction layer 223 sandwiched in the middle. The material of the second friction layer 223 is a polyimide (PI) film.

[0041] More specifically, when the wrist rotates, the first stator disk 214 of the speed sensing module 22 sweeps across the stator electrode group. Due to the difference in the length of the electrodes of the first stator disk 214, the voltage peak value changes. After every 9 sets of electrode scans are completed, a high-low-high-low-low-high-low-low-low characteristic waveform is output, which can be used to determine the direction of rotation. When rotating clockwise, the waveform is as described above. When rotating counterclockwise, the waveform can be observed as a low-low-low-high-low characteristic waveform. The signal frequency is linearly related to the rotation speed. One signal cycle corresponds to a rotation angle of twice the fan-shaped unit angle of 10°. Therefore, 360 / 10 is generated per rotation, which is 36 signal cycles. If there are f cycles per second, then the rotation speed per second is f / 36, from which the rotation speed can be obtained.

[0042] The pulse detection module 10 is realized through a flexible manufacturing process: first, Pt electrodes 102 are sputtered on a mica substrate, then Pt electrodes 102 are prepared on the surface of a PZT film 103, and finally, two PI films 101 are assembled to form a sandwich structure, and two copper wires are led out from the encapsulation layer to connect the top and bottom electrodes respectively; the completed pulse sensing element is embedded in the inside of the watchband and kept in close contact with the radial artery skin by elastic fabric; the arterial pulsation pressure causes the PZT film 103 to deform, and the output millivolt-level voltage signal fully presents the pulse wave and dicrotic notch characteristics.

[0043] This device innovatively achieves triple self-driving functionality: wrist rotation generates angular velocity signals through frictional electrification, and arterial pulsation generates pulse signals through piezoelectric effect; the entire device requires no external power supply and can operate on its own, maintaining stable operation in all-weather use scenarios of the prosthetic hand 3.

[0044] Example 2:

[0045] A self-driven multi-functional sensor for the wrist joint of a prosthetic hand, further comprising the self-driven multi-functional sensing device for the wrist joint of the prosthetic hand 3 in Embodiment 1, which solves the above-mentioned related technical problems and provides a solution for a stable and reliable self-driven angle and speed sensor that closely integrates the actual mechanical structure and application scenario of the prosthetic hand and is specifically designed for the wrist joint.

[0046] Example 3:

[0047] The test structure of the speed sensing module 22 includes a rotor substrate 401, a test rotor 402, a friction layer PTFE 403, a test stator 404, and a rotor substrate 405. The test stator 404 includes an X phase and a Y phase. The X phase consists of 10 sets of sector units, each set of sector units consisting of three pairs of electrodes (long, medium, and short). Odd-numbered and even-numbered sector units are connected to a circuit and externally connected to different wires. The Y phase consists of two rings of sector units with different intervals and sizes. These two sets of sector units are evenly and symmetrically divided into 8 parts, each part consisting of 6 sector units of different positions and sizes.

[0048] When the test rotor rotates, due to the difference in electrode length, a characteristic cyclic electrical signal is output. The X phase generates three regular "high-medium-low" signals, which can be used to determine the direction of rotation. When rotating clockwise, the waveform is as described above. When rotating counterclockwise, the waveform shows a low-medium-high characteristic waveform. The signal frequency is linearly related to the rotation speed, which can distinguish the direction of rotation. At the same time, since one signal cycle corresponds to twice the angle of the sector unit, the signal cycle generated per revolution can be known, and the rotation speed can be obtained.

[0049] When the rotor rotates, eight pairs of sequential binary signal codes are generated for the Y phase. For the inner ring, when the mixed electrical signal reaches an extreme point (peak or valley), it is recorded as "1", and otherwise as "0". For the outer ring, when the mixed electrical signal reaches a higher peak, it is recorded as "2" and a lower peak, it is recorded as "1", and otherwise as "0". Since the structure is designed with eight pairs of sequential binary codes every 45°, the fixed value of the angle can be obtained in degrees, and the resolution can reach 5.625°.

[0050] Meanwhile, the Y-phase conductor and the two conductors of the two-turn electrodes of the X-phase are connected to different serial ports respectively. A four-channel high-speed electrical measuring instrument can be connected to three different serial ports to simultaneously measure the "high, medium, and low" regular signals of the X-phase and the changes of the two different binary encoded signals of the Y-phase without interference between the signals.

[0051] Working Principle: This invention discloses a self-driven multifunctional sensor for the wrist joint of a prosthetic hand. Its working principle and usage method are based on triboelectricity and piezoelectric effect to achieve self-driven sensing. It can synchronously monitor the wrist joint angle, rotation speed, and radial artery pulse signal without an external power source. The overall structure of the sensor, from top to bottom, includes a prosthetic hand 3, an angle-velocity detection mechanism 2, and a pulse measurement ring 1. The angle-velocity detection mechanism 2 further includes an adjustment mechanism 20, an angle sensing module 21, and a velocity sensing module 22. These modules are all coaxially connected via a drive shaft 24 to achieve mechanical linkage. The angle sensing module 21 consists of a first rotor disk 212, a first friction... The system consists of layer 213 and a first stator disk 214. The first stator disk 214 uses 48 evenly distributed sector-shaped units, with odd-numbered units and even-numbered units connected independently. The first rotor disk 212 is designed with 24 sector-shaped units, initially corresponding one-to-one with the units of the first stator disk 214. When the wrist joint flexes and extends, external force drives the first rotor disk 212 to rotate relative to the first stator disk 214 via the drive shaft 24. The copper units of the first rotor disk 212 come into frictional contact with the first friction layer 213 (polytetrafluoroethylene film), generating charge transfer based on the principle of triboelectric nanogenerators. A continuous and stable sinusoidal alternating current signal is output from the electrodes of the first stator disk 214. Each signal cycle corresponds to a specific angle change. By calculating the number of signal cycles, the wrist rotation angle can be accurately determined. The speed sensing module 22 consists of a second rotor disk 222, a second friction layer 223, and a second stator disk 224. The second stator disk 224 is designed with 72 sector-shaped units, with each pair of units forming an electrode pair. Units are arranged in groups of nine, with the unit lengths following a "long-short-long-short-long-short-short-long" pattern. The second rotor disk 222 is configured with four evenly distributed pairs of long sector-shaped units. During wrist rotation, the second rotor disk 222 rubs against the second friction layer 223 (polyimide film), generating electrical charge. Due to the difference in electrode lengths, a characteristic cyclic electrical signal is output, cyclically every nine cycles. The group electrode scanning generates a periodic waveform of "high-low-high-low-low-high-low-low (missing the low)". This waveform can not only identify the direction of rotation (this waveform is for clockwise rotation and the waveform is reversed for counterclockwise rotation), but also the signal frequency is linearly related to the rotation speed. One signal cycle corresponds to a 10° rotation angle. The rotation speed can be derived by calculating the signal frequency. The pulse measurement ring 1 is integrated inside the watch band and includes a pulse detection module 10. This module adopts a flexible multilayer structure: a platinum bottom electrode (Pt electrode 102) is deposited on a mica substrate, then a PZT thin film 103 is covered and a top Pt electrode 102 is prepared. The whole is encapsulated between two PI films 101 and copper wires are led out to connect the electrodes.When the strap is worn on the wrist, the pulse detection module 10 is in close contact with the skin of the radial artery. The pressure of the arterial pulsation causes the PZT film 103 to deform, generating a millivolt-level voltage signal through the piezoelectric effect. The output waveform fully presents the pulse wave and dicrotic notch characteristics, realizing passive pulse monitoring. During use, the user only needs to attach the sensor to the wrist of the prosthetic hand 3 and perform normal wrist flexion, extension, and rotation movements. Angle and velocity signals are automatically generated through mechanical friction, while the pulse measurement ring 1 continuously captures physiological signals. All sensor signals are processed through a common circuit to achieve synchronous acquisition of motion parameters and health data. This design not only improves the accuracy of the prosthetic hand 3's control and natural interaction capabilities but also integrates health monitoring functions, extends the device's lifespan, and provides comprehensive motion feedback and health management support for people with disabilities. The entire sensor achieves efficient self-driving operation in a limited space through miniaturization (within 30 mm in diameter) and material optimization (such as PTFE and PI friction layers to ensure signal stability), making it suitable for all-weather use scenarios of the prosthetic hand 3.

[0052] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A self-powered multi-functional sensor for wrist joint of a prosthetic hand, characterized by, The utility model relates to a kind of prosthetic hand, angle-velocity detection mechanism and pulse measurement ring, including: Angle-velocity detection mechanism (2) including adjusting mechanism (20), angle sensing module (21) and speed sensing module (22) is arranged from top to bottom, adjusting mechanism (20), angle sensing module (21) and speed sensing module (22) are coaxially connected rotation by driving shaft (24), and adjusting mechanism (20) is composed of top shell (201) and regulator (202); The angle sensing module (21) includes a housing (23), a first rotor disc (212), a first friction layer (213), and a first stator disc (214). Under the action of an external force, the first rotor disc (212) rotates relative to the first stator disc (214). The first stator disc (214) is composed of forty-eight evenly distributed fan units. Odd fan units are connected to even fan units. The first rotor disc (212) is composed of twenty-four evenly distributed fan units, which have the same shape and size as the fan units of the first stator disc (214). The speed sensing module (22) includes adjusting mechanism (20), second rotor disc (222), second friction layer (223) and second stator disc (224). Under the action of an external force, the second rotor disc (222) rotates relative to the second stator disc (224). The second stator disc (224) is composed of seventy-two evenly distributed fan units. Each of the two fan units of the second stator disc (224) has the same size, and each pair of fan units forms a digital electrode. Every nine pairs of fan units form a group. The adjacent fan units of each group are arranged in a long-short-long-short-long-short-long-short-long arrangement. The second rotor disc (222) has four pairs of fan units, and the four pairs of fan units are evenly distributed. The pulse measurement ring (1) is composed of a wristband and a pulse detection module (10). The pulse detection module (10) is attached to the inner wall of the wristband and is used to tightly adhere to the radial artery on the wrist.

2. A self-powered multi-functional sensor for wrist joint of prosthetic hand according to claim 1, wherein, In the initial state, the angle sensing module (21) has one-to-one correspondence between the fan units of the first rotor disc (212) and the fan units of the first stator disc (214). Under the action of an external force, the first rotor disc (212) rotates and comes into contact and generates static electricity by rubbing with the first friction layer (213). The output signal is a stable sinusoidal electrical signal.

3. The self-powered multi-functional sensor for wrist joint of artificial hand according to claim 1, wherein, In the initial state, the speed sensing module (22) has one-to-one correspondence between the fan units of the first rotor disc (212) and the fan units of the first stator disc (214). Under the action of an external force, the first rotor disc (212) rotates and comes into contact and generates static electricity by rubbing with the second friction layer (223). The output is a regular alternating current signal with a cycle of every nine groups, and the signal is high-low-high-low-high-low-low cycle.

4. The self-powered multi-functional sensor for wrist joint of artificial hand according to claim 1, wherein, When the pulse detection module (10) is tightly attached to the radial artery of the human body, the output electrical signal can observe the pulse waveform. The angle-speed detection mechanism (2) and the pulse measurement ring (1) are measured by different serial ports (ch1, ch2, ch3, ch4) of a four-channel high-speed electric tester, and the signal changes can be measured simultaneously.

5. The self-powered multi-functional sensor for wrist joint of artificial hand according to claim 1, wherein, In the angle-speed detection mechanism (2), the angle sensing module (21) and the speed sensing module (22) are all etched Cu PCB boards, and the first stator disc (214) and the second stator disc (224) are etched on the front and back surfaces of the same PCB board. The diameter of the angle-speed detection mechanism (2) is 30 mm, and the inner diameter is 9 mm. The PCB board includes an upper PCB board (211), a middle PCB board (215), and a lower PCB board (221).

6. The self-powered multi-functional sensor for wrist joint of prosthetic hand according to claim 1, wherein The first stator disc (214) and the second stator disc (224) are inserted into three slots of a self-driven multifunctional sensor of the wrist joint of the artificial hand (3).

7. The self-powered multi-functional sensor for wrist joint of prosthetic hand according to claim 1, wherein In the angle sensing module (21), the first rotor disc (212) is connected to the adjusting mechanism (20), the first friction layer (213) is a PTFE film, and the odd and even fan-shaped units of the first stator disc (214) are connected to lead wires.

8. The self-powered multi-functional sensor for wrist joint of prosthetic hand according to claim 1, wherein, In the speed sensing module (22), the second rotor disc (222) is connected to the adjusting mechanism (20), the second friction layer (223) is a PI film (101), and the inner ring electrodes and independent electrodes (the independent electrodes are suspended fan-shaped electrodes that are not connected together, and the independent electrodes are welded into a circuit) of the second stator disc (224) are connected to lead wires.

9. The self-powered multi-functional sensor for wrist joint of prosthetic hand according to claim 1, wherein, The pulse detection module (10) further includes a flexible mica substrate, a platinum bottom electrode is deposited on the substrate, a Pt electrode (102) is deposited on a PZT thin film (103), and finally the sensor element is packaged between two PI films (101), the upper film has two copper wires connected to the top and bottom electrodes.

10. The self-powered multi-functional sensor for wrist joint of prosthetic hand according to claim 1, wherein, The test structure of the speed sensing module (22) includes a rotor substrate one (401), a test rotor (402), a friction layer PTFE (403), a test stator (404), and a rotor substrate two (405).

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