Flexible tendon sensing bracelet for identifying finger movement based on tendon movement

Abstract

The utility model discloses a flexible tendon sensing bracelet for recognizing finger movement based on tendon movement, and belongs to the technical field of gesture recognition. The bracelet comprises a sensing part and a non-sensing part, and the sensing part and the non-sensing part form an annular structure attached to the wrist part. The sensing part sequentially comprises an insulating protection layer, an upper metal foil electrode layer, a sensor layer, a lower metal foil electrode layer and a flexible protection layer from outside to inside; wherein the sensor layer is provided with four sensing units which respectively correspond to tendons in a projection area of the transverse wrist ligament. According to the utility model, the distributed sensor units are adopted, so that the robustness of the front-end sensing part can be remarkably improved, the accuracy of finger action recognition is improved, and the stability and reliability of the system are ensured; meanwhile, the device has the advantages of being portable, low in manufacturing cost and good in environmental adaptability, provides an efficient and economical communication tool for hearing-impaired people, and promotes barrier-free communication of the society.

Description

Technical Field

[0001] The utility model belongs to the technical field of gesture recognition, and particularly relates to a flexible tendon sensing bracelet for recognizing finger movement based on tendon activity. Background Art

[0002] In daily communication, there are communication barriers between hearing-impaired people and hearing people. Through sign language recognition technology, the sign language actions of hearing-impaired people can be converted into intuitive sound and text information, improving the convenience and authenticity of communication between the two parties.

[0003] Existing sign language recognition technologies mainly include glove-type sensor technology, which detects finger joint movements by installing sensors on gloves; camera capture technology, which analyzes hand movements using computer vision; and inertial measurement unit (IMU) recognition technology to detect the acceleration and rotation of the hand; fiber optic sensor capture technology for capturing hand bending and stretching, etc.

[0004] However, a series of defects have emerged in the application of existing sign language recognition technology solutions, which have greatly limited their wide application in real life.

[0005] The glove-type sensor technology has poor portability, making it inconvenient for users to wear in daily life, especially in situations where gloves need to be frequently changed. This inconvenience is particularly obvious. At the same time, the glove-type sensor technology is sensitive to environmental changes. Factors such as sweat and dust will affect the performance of the sensor, resulting in a decrease in recognition accuracy, which is a serious problem for scenarios that require precise sign language recognition.

[0006] The camera-based capture technology is overly dependent on light and background environment when recognizing sign language. Once the environmental light is insufficient or the background is complex and changeable, the performance of the recognition system will be greatly reduced. And the camera may raise concerns about privacy protection, which are all problems that need to be urgently solved in the existing technology.

[0007] In summary, the existing technology solutions are difficult to adapt to various different environmental conditions in actual use, resulting in a poor experience for users when outdoors or in places with large light changes. When using such devices, the wearing comfort is usually poor. In addition, the costs of existing technology solutions are generally high. Whether it is glove-type sensors or high-performance camera systems, their manufacturing costs and selling prices are high, which is not conducive to large-scale production and market popularization. The high cost not only limits the penetration rate of the product but also increases the burden on users. Summary of the Utility Model

[0008] In view of the problems existing in the prior art, such as portability, accuracy, cost, and environmental adaptability, the present utility model provides a flexible tendon sensing bracelet for recognizing finger movements based on tendon activities. The flexible tendon sensing bracelet for recognizing finger movements of the present utility model has the advantages of being easily portable, accurately recognizing hand movements, reducing manufacturing costs, and improving environmental adaptability, providing an efficient and economical communication tool for hearing-impaired people and promoting barrier-free communication in society.

[0009] The technical solution adopted by the present utility model is as follows:

[0010] A flexible tendon sensing bracelet for recognizing finger movements, characterized in that it includes a sensing part and a non-sensing part;

[0011] The sensing part and the non-sensing part are connected and fixed by means of glue or Velcro to form a ring structure that fits the wrist.

[0012] The non-sensing part is provided with a wireless transmission unit; the wireless transmission unit is used to send the received voltage signal to the backend processing module to recognize finger movements;

[0013] The sensing part, from the outside to the inside in sequence, is an insulating protective layer, an upper metal foil electrode layer, a sensor layer, a lower metal foil electrode layer, and a flexible protective layer; wherein, the sensor layer is provided with four sensing units, the upper metal foil electrode layer is provided with four upper electrode units, and the lower metal foil electrode layer is provided with four lower electrode units; when the sensing unit is subjected to pressure or tension, charges proportional to the magnitude of the pressure are generated, and the charges are transmitted to the wireless transmission unit in the form of voltage signals through the corresponding upper electrode units and lower electrode units and through independent wires.

[0014] Preferably, the four sensing units are respectively a first sensor unit, a second sensor unit, a third sensor unit, and a fourth sensor unit; wherein, the first sensor unit is arranged in the region of the extensor carpi ulnaris and the flexor carpi ulnaris; the second sensor unit is arranged in the region of the flexor digitorum profundus of the little finger, ring finger, and middle finger; the third sensor unit is arranged in the region of the flexor digitorum superficialis of the index finger and the flexor pollicis longus; the fourth sensor unit is arranged in the region of the abductor pollicis longus and the extensor pollicis brevis.

[0015] Preferably, the sensing unit adopts a pressure-strain type voltage sensor.

[0016] Preferably, the upper electrode unit, the sensor unit, and the lower electrode unit are interconnected by a hot pressing process.

[0017] Preferably, the upper metal foil electrode layer, the lower metal foil electrode layer are fixedly connected to the insulating protective layer and the flexible protective layer by an adhesive method; at the same time, the insulating protective layer and the flexible protective layer are also fixedly connected by an adhesive method in the non-sensing area.

[0018] Preferably, the non-sensing part is made of an elastic material.

[0019] The advantages of the present utility model are as follows:

[0020] 1. The present utility model divides the tendon dynamics characteristics in the projection area of the transverse carpal ligament into four independent detection areas, and a sensor unit is respectively arranged in each area. By specifically collecting the voltage signals in each area, the overlap and interference between signals are avoided, the intensity difference of the signals is increased, and thus the recognizability of the signals is enhanced. At the same time, the use of distributed sensor units can significantly improve the robustness of the front-end sensing part, enabling it to better adapt to the characteristics of different hand movements, improving the accuracy of finger movement recognition, and ensuring the stability and reliability of the system.

[0021] 2. The voltage signals collected by the four sensor units in the present utility model are transmitted to the wireless transmission unit through independent wires, avoiding the mutual interference and noise accumulation of the voltage signals during the transmission process, improving the signal-to-noise ratio of the signals, and ensuring the clarity of the signals. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the tendon partition of the wrist;

[0023] Figure 2 It is a schematic diagram of the flexible tendon sensing bracelet worn on the left hand;

[0024] Figure 3 It is a structural diagram of the sensor layers;

[0025] Figure 4 It is a top-down perspective view of the sensing unit.

[0026] Description of the reference numerals: 11. Sensing part, 12. Non-sensing part, 111. Insulating protective layer, 112. Upper metal foil electrode layer, 113. Sensor layer, 114. Lower metal foil electrode layer, 115. Flexible protective layer. Detailed Embodiment

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer and more understandable, the present utility model will be described in more detail below with reference to the drawings. It should be clear that the specific embodiments presented below are only illustrative descriptions of the present utility model and do not limit the scope of the present utility model.

[0028] In the conventional design, a complete sensor covers the entire wrist, and only a pair of electrodes are used for sensing. When the fingers are in motion, tendons in different regions move simultaneously, generating multiple signals that overlap on the sensor, resulting in signal confusion and interference. It is difficult to accurately distinguish the signals of each region. At the same time, signals of different intensities are mixed on the sensor, weakening the intensity difference of the signals and affecting the accuracy and recognizability of the signals.

[0029] Through anatomical research and practical observation, it is found that due to the geometric configuration of the carpal groove (curvature radius R = 12.7 ± 1.5 mm), the tendon is forced to produce non-uniform displacement at a specific motion phase, resulting in local strain concentration in the superficial sensitive area, while the adjacent area shows strain dispersion due to the change in the parallelism of the tendon path. Therefore, there are four regions with obvious amplitude changes during hand movement, such as Figure 1 shown, from left to right are the extensor carpi ulnaris and flexor carpi ulnaris regions (A); the flexor digitorum profundus of the little finger, ring finger, and middle finger regions (B); the flexor digitorum superficialis of the index finger and flexor pollicis longus regions (C); the abductor pollicis longus and extensor pollicis brevis (D). These four regions have obvious change characteristics during finger movement and can judge the tendon movement through the surface normal force. In other regions, due to the stress dispersion effect, the stress signals at the skin epidermis have been greatly lost, making it difficult to extract features and interfering with other regions at the same time.

[0030] Regarding the tendon situation of the wrist, a flexible tendon sensing bracelet for identifying finger movement based on tendon activity in this embodiment, such as Figure 2 shown, includes a sensing part and a non-sensing part.

[0031] Both the sensing part and the non-sensing part are in a semi-circular structure, and the two are connected and fixed by Velcro to form a circular structure that fits the wrist; the design of Velcro can be flexibly adjusted according to different wrist circumferences, and at the same time, the tightness of the bracelet can also be adjusted to ensure the comfort and stability of wearing.

[0032] The non-sensing part is made of an elastic material to fit the wrist; a wireless transmission unit is arranged in the non-sensing part; the wireless transmission unit is used to send the received voltage signal to the backend processing module to identify finger movement, and then translate sign language actions into text or voice;

[0033] The sensing part, such as Figure 3 shown, from the outside to the inside are an insulating protective layer, an upper metal foil electrode layer, a sensor layer, a lower metal foil electrode layer, and a TPU flexible protective layer. Among them, four sensing units are arranged in the sensor layer, four upper electrode units are arranged in the upper metal foil electrode layer, and four lower electrode units are arranged in the lower metal foil electrode layer; the upper electrode unit, the sensor unit, and the lower electrode unit are connected to each other through a hot pressing process.

[0034] The upper metal foil electrode layer, the lower metal foil electrode layer are fixedly connected to the insulating protective layer and the flexible protective layer by an adhesive method; at the same time, the insulating protective layer and the flexible protective layer are also fixedly connected by an adhesive method in the non-sensing area.

[0035] After the sensing part is laid flat, it is rectangular in shape, with an overall length of 70 mm and a width of 20 mm. Figure 4 The figure shows a distribution schematic diagram of four sensing units. The four sensing units are the first sensor unit ①, the second sensor unit ②, the third sensor unit ③, and the fourth sensor unit ④, which are realized by a pressure strain type voltage sensor. Among them, the first sensor unit is arranged in the extensor carpi ulnaris and flexor carpi ulnaris regions, that is, A corresponds to ①; the second sensor unit is arranged in the flexor digitorum superficialis of the little finger, ring finger, and middle finger regions, that is, B corresponds to ②; the third sensor unit is arranged in the flexor digitorum superficialis of the index finger and flexor pollicis longus regions, that is, C corresponds to ③; the fourth sensor unit is arranged in the abductor pollicis longus and extensor pollicis brevis regions, that is, D corresponds to ④. When the sensing units in each region are subjected to pressure or tension, charges proportional to the magnitude of the pressure are generated, and the charges are transmitted to the wireless transmitting unit in the form of voltage signals through the corresponding upper electrode unit and lower electrode unit and through independent wires.

[0036] The size system can be adaptively adjusted according to the wrist circumference size of the human body and the tendon distribution characteristics. By changing the width ratio of the blank unit to the sensing unit, the optimal distribution of the contact pressure is achieved. While maintaining the structural stability, the signal acquisition deviation caused by eccentric loading is avoided. In this embodiment, the size values with universality are given: L1 = 2.5 mm, L2 = 5 mm, L3 = 15 mm, L4 = 10 mm, L5 = 2.5 mm, L6 = 10 mm, L7 = 15 mm, L8 = 5 mm, L9 = 5 mm, L 10 = 20 mm, L 11 = 5 mm, L 12 = 5 mm, L 13 = 12.5 mm, L 14 = 10 mm, L 15 = 0.25 mm, L 16 = 10 mm, L 17 = 17.5 mm, L 18 = 5 mm, L 19 = 2.5 mm.

[0037] Due to the adoption of a four-channel sensor design, the sensing units in different regions will generate corresponding voltage signals according to the tendon movements in different parts of the wrist. These signals are transmitted through the corresponding electrodes and wires, and finally four-channel voltage signals are generated. The backend processing module can accurately recognize the sign language actions expressed by hearing-impaired people by analyzing the characteristics of the four-channel voltage signals, and convert them into corresponding text or voice information, thus realizing effective communication.

[0038] This four-channel sensor design not only improves the signal resolution, but also enhances the signal intensity difference, enabling the backend processing module to more accurately identify and analyze sign language actions. In addition, the four-channel sensor design can also reduce the noise interference during signal transmission and improve the signal-to-noise ratio. This enables the backend processing module to receive the signals in each region more clearly, further improving the accuracy of sign language action recognition.

Claims

1. A flexible tendon sensing bracelet for recognizing finger movement based on tendon activity, characterized in that, It includes a sensing part and a non-sensing part; The sensing part and the non-sensing part are connected and fixed by gluing or Velcro, forming a ring structure that fits the wrist; The non-sensing part is provided with a wireless transmitting unit; the wireless transmitting unit is used to send the received voltage signal to the backend processing module to identify finger movement; The sensing part, from the outside to the inside, is successively an insulating protective layer, an upper metal foil electrode layer, a sensor layer, a lower metal foil electrode layer, and a flexible protective layer; wherein, the sensor layer is provided with four sensing units, the upper metal foil electrode layer is provided with four upper electrode units, and the lower metal foil electrode layer is provided with four lower electrode units; when the sensing unit is subjected to pressure or tension, charges proportional to the magnitude of the pressure are generated, and the charges are transmitted to the wireless transmitting unit in the form of a voltage signal through the corresponding upper electrode unit and lower electrode unit and through independent wires.

2. The flexible tendon sensing bracelet for identifying finger movement based on tendon activity according to claim 1, wherein The four sensing units are respectively a first sensor unit, a second sensor unit, a third sensor unit, and a fourth sensor unit; wherein, the first sensor unit is arranged in the extensor carpi ulnaris and flexor carpi ulnaris regions; the second sensor unit is arranged in the flexor digitorum of the little finger, ring finger, and middle finger regions; the third sensor unit is arranged in the flexor digitorum of the index finger and flexor pollicis longus regions; the fourth sensor unit is arranged in the abductor pollicis longus and extensor pollicis brevis regions.

3. The flexible tendon sensing bracelet for identifying finger movement based on tendon activity according to claim 2, wherein, The sensing unit uses a pressure strain type voltage sensor.

4. The flexible tendon sensing bracelet for identifying finger movement based on tendon activity according to claim 3, characterized in that The upper electrode unit, the sensor unit, and the lower electrode unit are interconnected by a hot pressing process.

5. The flexible tendon sensing bracelet for recognizing finger movement based on tendon activity according to claim 4, wherein The upper metal foil electrode layer and the lower metal foil electrode layer are connected and fixed to the insulating protective layer and the flexible protective layer by gluing; at the same time, the insulating protective layer and the flexible protective layer are also connected and fixed by gluing in the non-sensing area.

6. The flexible tendon sensing bracelet for identifying finger movement based on tendon activity according to claim 5, wherein The non-sensing part uses an elastic material.

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