Diabetic foot biological feedback device and feedback method

Abstract

Based on the biological feedback principle, the diabetic foot biological feedback device and the control method are designed for solving the problems that an original gait mode of a diabetic foot patient is changed into an unreasonable abnormal gait and the plantar pressure is abnormal due to foot nerve or blood vessel lesion and foot touch degradation. The subject is actively regulated through biological feedback, so that the diabetic foot is prevented and slowed down. Pressure sensors are arranged to a second metatarsal bone of a forefoot area, a fourth metatarsal bone of the forefoot area and a heel bone of a heel area, and vibration motors are arranged to the outer side of a knee joint, the inner side of an ankle joint and the inner side of the knee joint of a leg on the same side; whether feedback data of the pressure sensor exceed a set threshold value or not is judged in the walking process of the user, and if yes, vibration motor intervention is conducted according to the incidence relation between the pressure sensor and the side vibration motor; therefore, the gait strategy of the wearer is corrected, and the effect of active biological feedback is achieved.

Description

Technical Field

[0001] This invention relates to the field of medical assistive rehabilitation equipment, specifically a biofeedback device for diabetic foot and a feedback method for controlling the biofeedback device for diabetic foot. Background Technology

[0002] The foot is a vital sensory organ, playing an indispensable role in sensory input during standing and walking. When the plantar tactile threshold is within an appropriate range, sensory feedback is stable, ensuring dynamic balance during movement. However, in patients with diabetic foot, due to nerve or vascular lesions in the foot, tactile sensation degenerates, and the corresponding tactile threshold increases. This disrupts the original gait pattern, and the abnormal gait pattern exacerbates the irrational distribution of plantar pressure, inhibiting effective force feedback between the foot and the ground. Abnormal plantar pressure significantly increases the risk of foot ulcers, and patients may even face the risk of lower limb amputation. Therefore, lowering the plantar pressure threshold and restoring the original tactile feedback is a feasible approach to slowing and preventing the progression of diabetic foot.

[0003] The human body is a complex chain system. In a control system, if the input part issues a command and the output part no longer provides feedback to the input part, it is an open-loop control system. A control system where the output part can provide feedback to the input part is a closed-loop control system. The difference lies in whether the signal from the output part can be fed back to the output part, or in other words, whether it can be perceived by the output part. The brain, as the main control center of the human body, operates in three main ways: voluntary control, automatic control, and subconscious control. 1) Voluntary operation: This is a generally understood mode of operation, performed through conscious awareness, such as eating, exercising, and reading. Due to the conscious state and the presence of visual, auditory, and tactile feedback during operation, these behaviors are often continuous, belonging to a closed-loop control system. 2) Automatic operation: This type of operation is also known as the vegetative nervous system, often essential for maintaining human life. Some automatic operations are controlled by voluntary operation. Even in the absence of consciousness, the brain's automatic operation maintains the normal functioning of various systems within the body. However, the human body cannot perceive the operation of these systems through self-awareness, belonging to an open-loop control system. 3) Subconscious activity, in contrast to conscious activity, is an involuntary brain activity. While the subconscious mind is usually not active in the conscious state, it often takes over when conscious awareness is weakened or absent.

[0004] The principle of biofeedback is primarily based on an automatically operating open-loop system. Traditional theory holds that organs controlled by the autonomic nervous system cannot learn, nor can they be controlled through conscious effort. However, biofeedback challenges this view. Through biofeedback training, subjects can actively adjust and alter the operation of various bodily systems, providing new insights into the prevention or relief of diabetic foot ulcers. Summary of the Invention

[0005] Based on the aforementioned principle of biofeedback, this invention addresses the problem of diabetic foot patients experiencing gait pattern changes into abnormal gait and abnormal plantar pressure due to nerve or blood vessel lesions in the sole of the foot. A biofeedback device for diabetic foot is designed to allow subjects to actively adjust their behavior through biofeedback, thereby preventing and slowing the onset of diabetic foot.

[0006] This invention provides a biofeedback device for diabetic foot, comprising:

[0007] Pressure sensors are located on the second metatarsal bone in the forefoot area, the fourth metatarsal bone in the forefoot area, and the calcaneus in the heel area, and are electrically connected to the controller module;

[0008] The controller module is used for voltage conversion, acquiring pressure changes from the thin-film pressure sensor, and outputting control signals for the vibration motor; the vibration motor is attached to the outside of the knee joint, the inside of the ankle joint, and the inside of the knee joint with tape, and is electrically connected to the controller module; the mobile power supply is used to provide power to the entire device and is electrically connected to the controller module.

[0009] According to claim 1, a biofeedback device for diabetic foot is characterized in that the pressure sensor is a wireless thin-film pressure sensor (FSR).

[0010] The vibration motor selected is the Risym 738 vibration motor.

[0011] The selected power bank has a capacity of 10000mAh, a rated capacity of 5600mAh, and an output current of 2.1A.

[0012] The signal from the pressure sensor in the second metatarsal bone of the forefoot is associated with the vibration motor on the lateral side of the knee joint;

[0013] The signal from the pressure sensor in the fourth metatarsal bone of the forefoot is associated with the vibration motor on the medial side of the knee joint;

[0014] The signal fed back by the pressure sensor on the calcaneus in the heel area is associated with the vibration motor on the inner side of the ankle joint.

[0015] This invention provides a biofeedback method for diabetic foot, comprising the following steps:

[0016] Step 1: Set pressure sensors to the second metatarsal bone in the forefoot area, the fourth metatarsal bone in the forefoot area, and the calcaneus in the heel area; set vibration motors to the lateral side of the knee joint, the medial side of the ankle joint, and the medial side of the knee joint on the same side of the leg.

[0017] Step 2, set the initial threshold: input the user's weight, habitual cadence, and habitual standing time to obtain the threshold;

[0018] Step 3: During the user's walking process, determine whether the pressure sensor feedback data exceeds the set threshold. If it exceeds the threshold, intervene with the vibration motor.

[0019] Step 4: Provide feedback based on the correlation between the pressure sensor and the side vibration motor;

[0020] The signal fed back by the pressure sensor in the second metatarsal bone of the forefoot is associated with the vibration motor on the lateral side of the knee joint;

[0021] The signal from the pressure sensor in the fourth metatarsal bone of the forefoot is associated with the vibration motor on the medial side of the knee joint;

[0022] The signal fed back by the pressure sensor on the calcaneus in the heel area is associated with the vibration motor on the medial side of the ankle joint;

[0023] Step 5: Repeat steps 3 and 4 until the pressure sensor feedback data returns to the threshold range during the user's walk.

[0024] Preferably, the threshold settings in steps 2 and 3 include:

[0025] A multi-attribute plantar pressure threshold scoring table is set up, with the first score based on the user's weight, the second score based on the user's habitual cadence, the third score based on the user's current standing time or habitual standing time, and the fourth score based on the percentage of total foot pressure at the detection point.

[0026] The first, second, third, and fourth scores are summed to obtain the threshold calculation score S. The pressure detected by the second metatarsal sensor, fourth metatarsal sensor, and calcaneal sensor when the user is standing normally is used as the baseline value F. The threshold calculation score is calculated accordingly.

[0027] When S≤20, the threshold pressure F0 is 0.8F; when 20<S≤40, the threshold pressure F0 is 0.9F; when 40<S≤60, the threshold pressure F0 is F; when 60<S≤80, the threshold pressure F0 is 1.1F; when 80<S<100, the threshold pressure F0 is 1.2F.

[0028] Preferably, in step 3, after the current standing time is reset to the value of the sensor pressure, the statistics begin when the pressure is obtained, and the third score generated by the previous standing time is added as the statistics time increases.

[0029] In step 3, the percentage of total foot pressure is calculated as: (the sum of the pressure values ​​obtained by the current sensors and the total pressure values ​​obtained by the second metatarsal sensor, the fourth metatarsal sensor, and the calcaneal sensor).

[0030] Preferably, the initial pressure sensor detection interval in step 3 is 1 second;

[0031] In step 4, when the pressure detected by the pressure sensor exceeds the threshold, the vibration motor starts to vibrate according to the associated sensor. The initial vibration time is 3 seconds. During the vibration, the pressure sensor does not detect the pressure. After the vibration ends, the pressure sensor detects the pressure immediately.

[0032] The vibration motor shuts off when the pressure sensor detects a pressure below the corresponding threshold; otherwise, it continues to vibrate.

[0033] Preferably, the vibration time in step 4 is adjusted according to the pressure detected by the pressure sensor in the previous continuous cycle.

[0034] F0 is the threshold pressure, F n+1 The pressure is the (n+1)th pressure detected by the current pressure sensor, and t is the vibration time.

[0035] When F n+1 If F is less than F0, then t is 0s.

[0036] When F n+1 If the gradient is greater than F0, the gradient calculation coefficient k = (F n+1 -F n ) / F n 0 <k<0.2,t=1s;0.2<k<0.4,t=2s;0.4<k<0.6,t=3s;0.6<k<0.8,t=4s;k> 0.8, t = 5s.

[0037] According to the present invention, a biofeedback device for diabetic foot involves real-time detection of plantar pressure at three anatomical feature points on the wearer's foot. When the plantar pressure at these feature points exceeds a reasonable threshold, a vibration motor triggers an alarm, thereby correcting the wearer's gait strategy and achieving an active biofeedback effect, preventing and delaying the progression of diabetic foot ulcers. The entire design process is low-cost and reasonable, therefore the biofeedback device for diabetic foot of the present invention is portable, versatile, and cost-effective. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating the pressure threshold determination process of the biofeedback device for diabetic foot of the present invention.

[0039] Figure 2 This is the pressure sensor setting point for the diabetic foot biofeedback device of the present invention;

[0040] Figure 3 This is the point of action of the vibration device in the biofeedback device for diabetic foot of the present invention;

[0041] Figure 4 This is a circuit diagram of the power module of the biofeedback device for diabetic foot of the present invention;

[0042] In the diagram: 101, the second metatarsal bone in the forefoot region; 102, the fourth metatarsal bone in the forefoot region; 103, the calcaneus in the heel region; 201, the lateral side of the knee joint; 202, the medial side of the knee joint; 203, the medial side of the ankle joint. Detailed Implementation

[0043] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0044] like Figure 2 and Figure 3 As shown, the present invention provides a biofeedback device for diabetic foot, which consists of the following four modules, including:

[0045] (1) Pressure Sensor: This design uses a wireless thin-film pressure sensor (FSR) for biofeedback device detection. The sensor consists of three parts: a strain-sensitive element (a metal foil with a high resistivity), a substrate and a cover layer, and lead wires. The advantages of the thin-film pressure sensor are its extremely small thickness, high flexibility, high sensitivity, and excellent repeatability. Most importantly, it can conform to the sole of the foot without affecting the user's normal walking. The sensing unit has a diameter of only 8mm, making it suitable for detecting pressure in specific areas of the sole. This sensor converts mechanical stress into a change in resistance, with a load range of 10g-10kg. The substrate and cover layer serve to fix and protect the sensitive element, transmit strain, and provide electrical isolation.

[0046] To convert the resistance value provided by the thin-film pressure sensor into data that can be read by the microcontroller in the controller module, the peripheral circuitry of the controller module includes a voltage acquisition circuit. Several identical voltage acquisition circuits are used to connect the thin-film pressure sensor to the acquisition terminal via an interface, and each voltage acquisition circuit is zeroed. By comparing the voltage value at the acquisition terminal with a given reference voltage value, the output terminal of the voltage acquisition circuit outputs the actual pressure value signal of each sensor to the microcontroller in the controller module.

[0047] (2) Controller Module: This module provides voltage acquisition (for obtaining pressure changes from the thin-film pressure sensor) and PWM wave output (this signal can be used to start the vibration motor). The measurable data provided by the thin-film pressure sensor is the resistance value, which cannot be directly used as data input for the vibration motor. Therefore, this module needs to preprocess the resistance data by converting the resistance value into voltage data that can be calibrated by the controller module. The converted voltage can be adjusted remotely according to the actual situation, thereby adjusting the duty cycle of the PWM wave. Finally, the PWM wave is transmitted to the vibration motor, and vibration feedback is activated.

[0048] (3) Vibration motor: Compared with auditory and visual feedback, vibration feedback is more discreet. The 738 vibration motor produced by Risym was selected in this design. It is driven and controlled by a MOSFET, with high-level triggering and low-level cutoff. It has the advantages of small size, long service life and strong vibration. It can be attached to the outside of the knee joint, the inside of the ankle joint and the inside of the knee joint respectively. The three vibration motors guide the subject to adjust the gait strategy of the second metatarsal, the fourth metatarsal and the calcaneus respectively.

[0049] The 738 vibration motor has three main pins: port 1 is the input of the PWM signal for control, which is output by the microcontroller in the controller module; port 2 is the input of 5V power, which is provided by the power supply module; and port 3 is grounded.

[0050] (4) Power Bank: The power bank is mainly responsible for powering the controller module. The power bank used in this design has a capacity of 10000mAh (37Wh) and a rated capacity of 5600mAh (2.1A).

[0051] like Figure 4 As shown, the power bank provides energy to the entire device through a power module. For powering the microcontroller, the 5V battery voltage needs to be converted to 3.3V; the step-down circuit uses an AMS1117 chip. The vibration motor can be directly powered by a 5V battery. (The text repeats itself here.) Figure 2 As shown, the three pressure sensors are respectively located on the second metatarsal bone 101 in the forefoot region, the fourth metatarsal bone 102 in the forefoot region, and the calcaneus bone 103 in the heel region;

[0052] The signal from the pressure sensor in the second metatarsal bone of the forefoot is associated with the vibration motor 201 on the lateral side of the knee joint;

[0053] The signal from the pressure sensor in the fourth metatarsal bone of the forefoot is associated with the vibration motor 202 on the medial side of the knee joint;

[0054] The signal fed back by the pressure sensor of the calcaneus in the heel area is associated with the vibration motor 203 on the medial side of the ankle joint.

[0055] The sensing unit has a diameter of 8mm, making it suitable for detecting pressure in specific areas of the sole. The sensor has a load range of 10g-10kg. The base layer and cover layer serve to fix and protect the sensitive element, transmit strain, and provide electrical isolation. Data is collected at three feature points on the sole, which is sufficient to meet the measurement needs of diabetic foot patients.

[0056] When the sensor detects that the plantar pressure exceeds a pre-set threshold, the wearer can perceive a slight vibration. Upon vibration, the wearer actively adjusts their gait strategy. There are three gait strategies: Strategy M2, which reduces pressure on the second metatarsal; Strategy M4, which reduces pressure on the fourth metatarsal; and Strategy H, which reduces pressure on the calcaneus. The frequency of vibrations gradually decreases as the gait strategy changes, thus achieving a biofeedback effect.

[0057] like Figure 1 As shown, this invention provides a biofeedback method for diabetic foot.

[0058] Step 1: Set pressure sensors to the second metatarsal bone in the forefoot area, the fourth metatarsal bone in the forefoot area, and the calcaneus in the heel area; set vibration motors to the lateral side of the knee joint, the medial side of the ankle joint, and the medial side of the knee joint on the same side of the leg.

[0059] Step 2, set the initial threshold: input the user's weight, habitual cadence, and habitual standing time to obtain the threshold;

[0060] Step 3: During the user's walking process, determine whether the pressure sensor feedback data exceeds the set threshold. If it exceeds the threshold, intervene with the vibration motor.

[0061] Step 4: Provide feedback based on the correlation between the pressure sensor and the side vibration motor;

[0062] The signal fed back by the pressure sensor in the second metatarsal bone of the forefoot is associated with the vibration motor on the lateral side of the knee joint;

[0063] The signal from the pressure sensor in the fourth metatarsal bone of the forefoot is associated with the vibration motor on the medial side of the knee joint;

[0064] The signal fed back by the pressure sensor on the calcaneus in the heel area is associated with the vibration motor on the medial side of the ankle joint;

[0065] Step 5: Repeat steps 3 and 4 until the pressure sensor feedback data returns to the threshold range during the user's walk.

[0066] The collected plantar pressure data is analyzed to determine whether the pressure value at the feature point is greater than the set threshold. If the result is negative, the plantar pressure detection continues. If the result is positive, the vibration motor initiates an alarm signal to provide further vibration intervention to the wearer.

[0067] For the set thresholds: When using the biofeedback device for wearers with diabetic foot, the threshold for plantar pressure alerts will be adjusted based on each wearer's weight, average cadence per minute, standing time during gait cycles, and percentage of plantar pressure under different gait strategies (strategy M2 corresponds to the second metatarsal, strategy M4 corresponds to the fourth metatarsal, and strategy H corresponds to the calcaneus). Table 1 shows the multi-attribute plantar pressure threshold scoring table. The total score is 100 points. For each subject, the pressure detected by the second metatarsal sensor, fourth metatarsal sensor, and calcaneus sensor during normal standing is used as the baseline value F. When the score is ≤20, the threshold pressure F0 is 0.8F; when 20 < score ≤40, the threshold pressure F0 is 0.9F; when 40 < score ≤60, the threshold pressure F0 is F; when 60 < score ≤80, the threshold pressure F0 is 1.1F; and when 80 < score <100, the threshold pressure F0 is 1.2F. Ultimately, by adjusting the duty cycle of the PWM wave through the controller module, the threshold can be set, making it suitable for different wearers.

[0068] Table 1. Multi-attribute plantar pressure threshold scoring table

[0069]

[0070] Motor vibration intervention: When the set threshold is exceeded and the judgment result is yes, the increased plantar pressure will cause the voltage value read by the controller module to increase. Then, the vibration motor will be controlled by adjusting the PWM wave to alert the subject and prompt them to change their gait so that the plantar pressure at the location of the thin film pressure sensor will decrease. When the vibration signal is received, the wearer will adjust their gait strategy according to the vibration signal.

[0071] After the vibration motor intervenes, the device continuously monitors plantar pressure data and continuously determines whether it exceeds the threshold. Simultaneously, the wearer actively adjusts their gait strategy based on the vibration motor's prompts, achieving a biofeedback effect. Because diabetic foot patients cannot sensitively perceive changes in foot impact, the biofeedback training of this diabetic foot biofeedback device can correct abnormal gait strategies and reduce excessively high plantar pressure in the foot area. Therefore, this device aims to delay and prevent the occurrence of diabetic foot ulcers.

[0072] Example 1

[0073] We used a 3D gait and motion analysis system manufactured by Dechang, which is a wireless wearable full-body motion capture and gait analysis device. As required, 17 wireless motion sensors were fixed to the corresponding body parts of the subject with straps, which can measure the three-dimensional angle data of the knee, hip, and ankle joints.

[0074] In the experimental example, this device combines data analysis from wireless wearable full-body motion capture and gait analysis equipment. We designed a gait strategy adjustment scheme based on vibration feedback. The adjustment strategy is based on the angle changes of the hip, knee, and ankle joints along the coronal (X-axis), vertical (Y-axis), and sagittal (Z-axis) axes during normal walking.

[0075] 1) Strategy M2: When the pressure detected by the second metatarsal sensor exceeds the set pressure threshold F0, the lateral knee vibrator is activated to remind the user to adjust their posture by adducting the knee and externally rotating and abducting the ankle.

[0076] 2) Strategy M4: When the pressure detected by the fourth metatarsal sensor exceeds the set pressure threshold F0, the medial ankle vibrator is activated to remind the user to adjust their posture by external rotation and eversion of the ankle, adduction of the hip joint, and flexion of the knee joint.

[0077] 3) Strategy H: When the pressure detected by the heel bone sensor exceeds the set pressure threshold F0, the medial knee vibrator is activated to remind the user to adjust their posture by external rotation of the hip joint and flexion of the knee joint.

[0078] In this embodiment, to verify the feasibility and effectiveness of the diabetic foot biofeedback device and to train a guiding gait strategy adjustment scheme, six normal subjects were recruited a priori, including five men and one woman, aged between 20 and 30 years old. All six subjects were assessed by medical institutions as having no neurological diseases or any lower limb injuries that could affect natural gait behavior. Due to individual differences, most normal subjects also had some degree of abnormal plantar pressure distribution.

[0079] Step 1: Each subject wore a diabetic foot biofeedback device for simulated gait training, through which sensors acquired plantar pressure data.

[0080] Step 2: This device analyzes and determines the acquired plantar pressure data, and then determines whether to turn on the vibration motor.

[0081] Step 3 adjusts the gait strategy based on the alarm signal from the vibration motor. Before the vibration motor generates vibration, the detection time of this device is 1 second. When the pressure detected by the sensor exceeds the threshold, the controller module sends a PWM wave, and the vibration motor receives the alarm signal and generates vibration (initial vibration time is 3 seconds). After the vibration ends, real-time plantar pressure detection is performed again. When the pressure detected by the sensor is lower than the threshold, the vibration motor shuts off. During the experiment, the number of vibrations under different gait strategies is recorded and the significance is compared. Vibration feedback is as follows: F0 is the threshold pressure, F... n+1 The pressure is the (n+1)th time the sensor detects, and t is the vibration time.

[0082] When F n+1 If F is less than F0, then t is 0s.

[0083] When F n+1 If the gradient is greater than F0, the gradient calculation coefficient k = (F n+1 -F n ) / F n 0 <k<0.2,t=1s;0.2<k<0.4,t=2s;0.4<k<0.6,t=3s;0.6<k<0.8,t=4s;k> 0.8, t = 5s; under dynamic feedback, the closer the feedback is to the correct answer, the shorter the feedback time.

[0084] Finally, in step 4, the Dechang wireless wearable full-body motion capture and gait analysis device can analyze the changes in the angles of the ankle, knee, and hip joints during the subject's gait task by actively adjusting different gait strategies (strategy M2, strategy M4, strategy H) through feedback (see Table 4).

[0085] Table 4. Average percentage change in lower limb joint angles corresponding to different walking strategies in subjects

[0086]

[0087] The changes in plantar pressure also confirmed that these strategies (strategy M2, strategy M4, strategy H) did indeed alter and reduce plantar pressure in the corresponding areas (see Tables 2 and 3).

[0088] Table 2. Average percentage of plantar pressure under different time-state strategies

[0089]

[0090] Table 3. Average percentage reduction in peak pressure in the target area by different walking strategies

[0091]

[0092] In the experiment, participants improved their gait based on the distribution of plantar pressure. Four gait strategies were used: normal walking as the control group; strategy M2 (reducing pressure on the second metatarsal), strategy M4 (reducing pressure on the fourth metatarsal), and strategy H (reducing pressure on the calcaneus). Finally, gait analysis and ankle joint angle measurements verified the feasibility and effectiveness of the strategies. The results are as follows: Table 2 measures the average percentage of plantar pressure under different gait strategies; Table 3 measures the average percentage reduction in peak pressure in the target area under different gait strategies; and Table 4 shows the average percentage change in lower limb joint angles corresponding to different walking strategies based on normal walking as a baseline.

[0093] According to the present invention, a biofeedback device for diabetic foot involves real-time detection of plantar pressure at three anatomical feature points on the wearer's foot. When the plantar pressure at these feature points exceeds a reasonable threshold, a vibration motor triggers an alarm, guiding and correcting the wearer's gait strategy to achieve active biofeedback, thus preventing and delaying the progression of diabetic foot ulcers. The entire design process is low-cost and reasonable, therefore the biofeedback device for diabetic foot of the present invention is portable, versatile, and cost-effective.

[0094] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A biofeedback method for diabetic foot, characterized in that: The following steps are involved: Step 1, setting pressure sensors to the second metatarsal bone in the forefoot area, the fourth metatarsal bone in the forefoot area and the heel bone in the heel area, and setting vibration motors to the outside of the knee joint, the inside of the ankle joint, and the inside of the knee joint of the same leg; Step 2, perform initial threshold setting: input the user's weight, habitual cadence, habitual standing time, and obtain the threshold; Step 3, during the user's walking process, determining whether the pressure sensor feedback data exceeds a set threshold, and if so, performing vibration motor intervention; Step 4, providing feedback based on the correlation between the pressure sensor and the side vibration motor; The signal fed back by the pressure sensor of the second metatarsal bone in the forefoot area is associated with the vibration motor on the outside of the knee joint; The signal fed back by the pressure sensor of the fourth metatarsal in the forefoot area is associated with the vibration motor on the inside of the knee joint; The signal fed back by the pressure sensor of the heel bone in the heel area is associated with the vibration motor on the inside of the ankle joint; Step 5, repeating steps 3 and 4 until the pressure sensor feedback data returns to within the threshold range while the user is walking.

2. A diabetic foot biofeedback method according to claim 1, characterized in that: The threshold settings in steps 2 and 3 include: Set up a multi-attribute plantar pressure threshold scoring table, obtain a first score based on the user's weight, obtain a second score based on the user's habitual cadence, obtain a third score based on the user's current standing time or habitual standing time, and obtain a fourth score based on the proportion of the total foot pressure at the detection point; The first score, the second score, the third score and the fourth score are accumulated to obtain a threshold calculation score S, and the pressure detected by the second metatarsal sensor, the fourth metatarsal sensor and the heel bone sensor when the user is standing normally is set as a baseline value F, according to the calculation score; When S≤20, the threshold pressure F0 is 0.8F; when 20<S≤40, the threshold pressure F0 is 0.9F; when 40<S≤60, the threshold pressure F0 is F; when 60<S≤80, the threshold pressure F0 is 1.1F; when 80<S<100, the threshold pressure F0 is 1.2F.

3. A diabetic foot biofeedback method according to claim 2, characterized in that: In step 3, after the current standing time is cleared with the sensor pressure being counted, the counting starts when the pressure is obtained, and the third score generated by the previous standing time is added with the counting time; In step 3, the total foot pressure ratio is calculated by dividing the pressure value obtained by the current sensor by the sum of the pressure values ​​obtained by the second metatarsal sensor, the fourth metatarsal sensor, and the heel bone sensor.

4. A diabetic foot biofeedback method according to claim 3, characterized in that: In step 3, the initial pressure sensor detection interval is 1s; In step 4, when the pressure detected by the pressure sensor exceeds the threshold, the vibration motor starts to vibrate according to the associated sensor. The initial vibration time is 3 seconds. The pressure sensor detection is not performed during the vibration. The pressure sensor detection is performed immediately after the vibration ends. When the pressure detected by the pressure sensor is lower than the corresponding threshold, the vibration motor is turned off, otherwise it continues to vibrate.

5. A diabetic foot biofeedback method according to claim 3, characterized in that: The vibration time in step 4 is changed according to the pressure detected by the pressure sensor last time; F0 is the threshold pressure, F n+1 is the pressure detected by the current pressure sensor for the n+1th time, and t is the vibration time; When F n+1 Less than F0, t is 0s, When F n+1 Greater than F0, the gradient calculation coefficient k=(F n+1 -F n ) / F n , 0 <k<0.2,t=1s;0.2<k<0.4,t=2s;0.4<k<0.6,t=3s; 0.6 <k<0.8,t=4s;k> 0.8, t=5s.

6. The diabetic foot biofeedback device according to claim 1, characterized in that: The pressure sensor uses wireless film pressure sensor FSR; The vibration motor uses the 738 vibration motor produced by Risym; The power bank is selected with a capacity of 10000mAh, a rated capacity of 5600mAh, and an output current of 2.1A; The signal fed back by the pressure sensor of the second metatarsal bone in the forefoot area is associated with the vibration motor on the outside of the knee joint; The signal fed back by the pressure sensor of the fourth metatarsal in the forefoot area is associated with the vibration motor on the inside of the knee joint; The signal fed back by the pressure sensor on the heel bone in the heel area is associated with the vibration motor on the inside of the ankle joint.

7. A biofeedback device for diabetic foot, characterized in that: include: The pressure sensor is arranged at the second metatarsal bone in the forefoot area, the fourth metatarsal bone in the forefoot area and the heel bone in the heel area, and is electrically connected to the controller module; A controller module, used for voltage conversion, obtaining pressure changes of the thin film pressure sensor, and outputting vibration motor control signals; The vibration motor is attached to the outside of the knee joint, the inside of the ankle joint, and the inside of the knee joint by means of adhesive tape, and is electrically connected to the controller module; The mobile power supply is used to provide power for the entire device and is electrically connected to the controller module.

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