A flexible finger joint bending angle detection device

Abstract

This invention provides a flexible finger joint bending angle detection device, comprising: an encapsulation layer, a dielectric layer, an electrode layer, and a fixing strip arranged from bottom to top; and a wire located between the fixing strip and the electrode layer, the wire being connected to the electrode layer; the dielectric layer completely covers the electrode layer; the encapsulation layer completely covers the dielectric layer; and the fixing strip is adjustable in size. The technical solution of this invention overcomes the problems of rigid structures in existing sensors being unsuitable for bending and having poor wearing comfort.

Description

Technical Field

[0001] This invention relates to the field of flexible sensor technology, and specifically to a flexible finger joint bending angle detection device. Background Technology

[0002] Rheumatoid arthritis (RA) is an autoimmune disease with an unclear etiology, characterized primarily by chronic, symmetrical, polyarthritis. The initial symptoms of RA are stiffness, pain, and deformities in the small joints of the extremities. The proximal interphalangeal and metacarpophalangeal joints are the most commonly affected sites. Currently, most patients and their families lack sufficient understanding of the disease, neglect joint protection, and receive inadequate health education in the early stages. Due to the long duration of the disease, rehabilitation treatment for RA patients should be tailored to different stages of the disease. The commonly used clinical standard for assessing joint activity is the DAS28 score, also known as the 28-Joint Disease Activity Score. This score assesses the tenderness count, swelling count, joint function status, erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) levels in 28 joints, as well as the patient's overall self-assessment. These assessment indicators are then calculated using a formula to derive a score. The score indicates the patient's joint activity level. Rheumatoid arthritis activity is extremely important for monitoring changes in joint function, assessing treatment effectiveness, and evaluating the degree of disease remission. Doctors can use disease activity data to understand the current stage of a rheumatoid arthritis patient's condition and to assess the effectiveness of previous treatments. However, due to the long treatment cycle and slow results, doctors need to change the treatment plan promptly if the patient's condition does not improve. Furthermore, because the affected areas are often in the joints of the limbs, patients experience stiffness and other symptoms when their joints are inactive for extended periods, which affects the assessment. Traditional sensors, due to their rigid structure, are not easily bent and have poor wearing comfort, resulting in poor measurement of joint mobility. To ensure the safety and health of patients, there is an urgent need for a flexible finger joint flexion angle detection device, but such a device is currently unavailable on the market.

[0003] Therefore, there is a need for a flexible finger joint bending angle detection device that can be bent and is comfortable to wear. Summary of the Invention

[0004] The main objective of this invention is to provide a flexible finger joint bending angle detection device to solve the problems of rigid structure of traditional sensors in the prior art, which are not suitable for bending and have poor wearing comfort.

[0005] To achieve the above objectives, the present invention provides a flexible finger joint bending angle detection device, comprising: an encapsulation layer, a dielectric layer, an electrode layer, and a fixing strip arranged from bottom to top, and further comprising a wire located between the fixing strip and the electrode layer, the wire being connected to the electrode layer, the dielectric layer completely covering the electrode layer, the encapsulation layer completely covering the dielectric layer, and the fixing strip being adjustable in size.

[0006] Furthermore, the fixing strip is made of nylon and PUR rubber.

[0007] Furthermore, the dielectric layer is made of a mixture of polydimethylsiloxane and barium titanate.

[0008] Furthermore, the encapsulation layer is made of polyimide.

[0009] Furthermore, the electrode layer is made of copper tape, and the wires are attached to the fixed strip via the copper tape.

[0010] Furthermore, the conductor is made of copper and has a diameter of 0.2 mm.

[0011] Furthermore, the dielectric layer is made by mixing polydimethylsiloxane and barium titanate in a mass ratio of 4:1, adding a curing agent and stirring evenly, then vacuum-extracting the air bubbles and coating it onto the copper electrode, and then drying it in an oven at 70°C.

[0012] The present invention has the following beneficial effects:

[0013] 1. Traditional sensors, due to their rigid structure, are not easy to bend and have poor wearing comfort, resulting in poor measurement of human joint range of motion. Flexible sensors are easy to bend, wearable, and portable. Using movable straps, they can be adjusted for different people and different finger thicknesses and lengths, which is flexible and universal, and easy to disassemble and has good durability.

[0014] 2. Fix the two electrodes onto the strip respectively. When using, fix the strip to both ends of the finger joint. This allows for rotation around the joint as an axis. The measurement of the joint bending angle can be converted into the measurement of the capacitance change value. Later, curve fitting can be performed to deduce the angle of joint rotation.

[0015] 3. Using a mixture of polydimethylsiloxane (PDMS) and barium titanate (BaTiO3) as the dielectric layer increases both the bending resistance and the dielectric constant, thereby increasing the capacitance change and the initial capacitance value, as well as the stability of the capacitance value.

[0016] 4. The device is encapsulated using PI (polyimide), which is resistant to acids and alkalis, has good insulation properties, withstands low and high temperatures, and has good solvent resistance, allowing for sterilization with alcohol. The manufacturing process is convenient, and it can be used with AD conversion chips for multi-channel sampling, enabling the acquisition of bending angles from multiple fingers, thus reducing patient discomfort. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0018] Figure 1 A schematic diagram of the overall structure of a flexible finger joint bending angle detection device according to the present invention is shown.

[0019] Figure 2 It shows Figure 1 A side cross-sectional view of a flexible finger joint bending angle detection device;

[0020] Figure 3 It shows the use of Figure 1 A schematic diagram illustrating the specific method of a flexible finger joint bending angle detection device;

[0021] Figure 4 It shows Figure 3 Another perspective diagram.

[0022] The reference numerals in the above figures are as follows:

[0023] 1. Fixed strip; 2. Conductor; 3. Encapsulation layer; 4. Dielectric layer; 5. Electrode layer. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 and Figure 2The device shown is a flexible finger joint bending angle detection device, which includes: an encapsulation layer 3, a dielectric layer 4, an electrode layer 5 and a fixing strip 1 arranged from bottom to top, and a wire 2 located between the fixing strip 1 and the electrode layer 5. The wire 2 is connected to the electrode layer 5. The dielectric layer 4 completely covers the electrode layer 5, and the encapsulation layer 3 completely covers the dielectric layer 4. The size of the fixing strip 1 can be adjusted.

[0026] like Figure 3 and Figure 4 As shown, when using this device, the fixing strip 1 is adjusted to the most suitable size for the finger being tested. The side with the encapsulation layer 3, dielectric layer 4, and electrode layer 5 is adjusted to the palm side of the finger and fixed above the finger joint. The same device is fixed below the finger joint, and the side with the encapsulation layer 3, dielectric layer 4, and electrode layer 5 is also placed on the palm side, forming a non-parallel plate capacitor. When the finger joint is bent, as the bending angle of the finger joint increases, the distance between the encapsulation layer 3, dielectric layer 4, and electrode layer 5 of the two devices gradually decreases. The facing area and spacing of the electrode layer 5, as well as the relative permittivity of the dielectric layer 4, will change. The capacitance of the device is measured by the testing system. By collecting the change in capacitance and comparing it with the fitted curve, the bending angle of the joint can be obtained. This device realizes the function of collecting the bending angle of the finger joint and achieves the purpose of testing the degree of finger joint activity in patients with arthritis.

[0027] Specifically, the fixing strip 1 is made of nylon and PUR rubber. This material is harmless to the human body.

[0028] Specifically, dielectric layer 4 is made of a mixture of polydimethylsiloxane (PDMS) and barium titanate (BaTiO3). This increases both the bending resistance and the dielectric constant, thereby increasing the capacitance change and the initial capacitance value, as well as the stability of the capacitance value.

[0029] Specifically, the encapsulation layer 3 is made of polyimide (PI). Using PI for encapsulation provides good resistance to acids and alkalis, excellent insulation, resistance to low and high temperatures, and good solvent resistance, allowing the device to be sterilized with alcohol. The manufacturing process is convenient, and it can be used with an AD conversion chip for multi-channel sampling, enabling the acquisition of bending angles of multiple fingers, reducing patient discomfort.

[0030] Specifically, the electrode layer 5 is made of copper tape, and the wire 2 is attached to the fixed strip 1 by means of the copper tape.

[0031] Specifically, conductor 2 is made of copper and has a diameter of 0.2 mm.

[0032] Specifically, use sandpaper to grind off the insulation layer at both ends of the wire 2, connect one end to the electrode layer 5, and connect the other end to the tester.

[0033] Specifically, dielectric layer 4 is made by mixing polydimethylsiloxane and barium titanate in a mass ratio of 4:1, adding a curing agent and stirring evenly, then vacuum-extracting the air bubbles and coating it onto the copper electrode, and then drying it in an oven at 70°C.

[0034] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A joint bending angle detection method based on a flexible finger joint bending angle detection device, characterized by, The device includes, from bottom to top, an encapsulation layer, a dielectric layer, an electrode layer, and a fixed strip, and also includes a wire located between the fixed strip and the electrode layer, the wire being connected to the electrode layer, the dielectric layer completely covering the electrode layer, the encapsulation layer completely covering the dielectric layer, and the fixed strip being adjustable in size; The testing method includes: adjusting the fixing strip of one device to the size most suitable for the finger being tested, adjusting the side with the encapsulation layer, dielectric layer, and electrode layer to the palm side of the finger, and fixing it above the finger joint using the fixing strip; placing the side of the same device with the encapsulation layer, dielectric layer, and electrode layer on the palm side of the hand, and fixing it below the finger joint using the fixing strip; the two devices are fixed on both sides of the finger joint to form a non-parallel plate capacitor; bending the finger joint, as the bending angle of the finger joint increases, the distance between the encapsulation layer, dielectric layer, and electrode layer of the two devices gradually decreases, and the facing area, spacing, and relative permittivity of the dielectric layer of the electrode layer all change; measuring the capacitance of the devices through a testing system; and obtaining the joint bending angle by collecting the change in capacitance and comparing it with a fitted curve.

2. The method for detecting joint bending angle according to claim 1, characterized in that, The fixed strip is made of nylon and PUR rubber.

3. The method for detecting joint bending angle according to claim 1, characterized in that, The dielectric layer is made of a mixture of polydimethylsiloxane and barium titanate.

4. The method for detecting joint bending angle according to claim 1, characterized in that, The encapsulation layer is made of polyimide.

5. The method for detecting joint bending angle according to claim 1, characterized in that, The electrode layer is made of copper tape, and the wires are attached to the fixed strip by the copper tape.

6. The method for detecting joint bending angle according to claim 5, characterized in that, The conductor is made of copper and has a diameter of 0.2 mm.

7. The method for detecting joint bending angle according to claim 3, characterized in that, The dielectric layer is made by mixing polydimethylsiloxane and barium titanate in a mass ratio of 4:1, adding a curing agent and stirring evenly, then vacuuming out air bubbles and coating it onto a copper electrode, and then drying it in an oven at 70°C.

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