An adjustable airbag pelvic floor muscle biofeedback trainer

Abstract

The utility model relates to an adjustable air bag type pelvic floor muscle biofeedback trainer, and particularly relates to the technical field of medical apparatus and instruments. The adjustable air bag type pelvic floor muscle biofeedback trainer is composed of a medical silica gel air bag, a pressure regulating module, a pressure sensor, a main control unit and a display terminal. The air bag is provided with annular convex textures and is divided into a proximal chamber and a distal chamber; the pressure regulating module is connected with a micro air pump and an electromagnetic valve through a tee joint; a silicon piezoresistive sensor is embedded in a double air guide pipe to detect pressure in real time; the main control unit drives an air path and processes data, which are transmitted to the display terminal through SPI or wireless communication. The pneumatic structure realizes biomechanical feedback in the mechanical domain, and through independent regulation and control of the double chambers, dynamic adaptation of the air bag and rapid pressure response, the training precision and adaptability are improved, the biofeedback mechanism is converted from the electrophysiological domain to the mechanical domain, the "detection-feedback-regulation" closed loop is realized through the pneumatic structure innovation, a high cost-effective solution is provided for the pelvic floor rehabilitation field, and the hardware cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically relating to an adjustable airbag-type pelvic floor muscle biofeedback trainer. Background Technology

[0002] Pelvic floor muscle dysfunction, a common postpartum and geriatric condition, urgently requires safe and effective rehabilitation training devices. Traditional biofeedback trainers generally employ rigid probes with built-in electromyography (EMG) sensors, which have significant drawbacks: First, the fixed probe diameter cannot adapt to different physiological structures, especially in patients with severe pelvic floor muscle laxity, where insufficient probe fit leads to signal distortion; second, EMG signals require complex algorithm conversion to obtain muscle strength assessment results, making it difficult for users to intuitively understand abstract electrophysiological data, significantly reducing training compliance; third, high-precision EMG detection modules and multi-channel electrical stimulation circuits increase manufacturing costs, hindering widespread adoption in home use. While existing technologies attempt to improve comfort by wrapping the probe with flexible materials, they do not resolve the fundamental contradiction between the biomechanical feedback mechanism and individualized adaptation, and lack precise control methods for zonal training of the pelvic floor muscle groups.

[0003] Studies have shown that variations in pelvic floor muscle laxity result in vaginal diameter changes ranging from 2.5 to 4.0 cm (ultrasound measurement data). Traditional rigid probes, with a fixed diameter (mostly 3.0 cm), achieve less than 40% fit for patients with laxity (diameter > 3.5 cm) (pressure sensor testing). Furthermore, the contact area between the rigid probe and the pelvic floor muscles is only 0.8-1.2 cm². 2 (3D scan data) Pain is triggered when local pressure >15kPa (pain threshold test), leading to a 58% decrease in patient compliance (clinical statistics). Electromyography (EMG) signal amplitude is only 10-100μV (surface EMG detection), easily affected by respiration and posture, resulting in a low signal-to-noise ratio (SNR <10dB). Existing devices require complex algorithms such as Fast Fourier Transform (FFT) and Independent Component Analysis (ICA) to extract muscle strength information, resulting in data latency >500ms (real-time performance test), making it difficult for users to establish a motion-feedback relationship. High-precision EMG acquisition modules (such as the ADS1299 chip) account for 60% of the cost, and multi-channel electrical stimulation circuits (such as the TPSH7500) further increase manufacturing costs to 2000 RMB per unit, far exceeding the affordability of home users. In addition, the pelvic floor muscles are divided into five subgroups, including the pubococcygeus and iliococcygeus muscles. The peak pressure generated during the contraction of each muscle group differs by 30-50% (detected by a micro-pressure sensor array). Existing single-chamber airbags cannot achieve differentiated stimulation. Clinical studies show that the activation efficiency of a single training program varies by ±25% for different muscle groups (EMG detection).

[0004] While existing improvements employ flexible materials to encase the probe and enhance comfort, they fail to resolve the fundamental contradiction between mechanical feedback mechanisms and individualized adaptation, and lack precise control over pelvic floor muscle group training. For example, some solutions reduce contact pressure to 8-12 kPa by encasing the probe in silicone, but still lack an active adjustment mechanism and rely on manual operation; another type uses a combination of pressure sensors and springs, with fixed spring stiffness and a mechanical response time >300 ms. Furthermore, the three-chamber airbag design increases the equipment failure rate by 45% due to its complex control logic. None of these technologies overcome the core defects of traditional solutions and cannot meet the clinical demand for safe, efficient, and portable rehabilitation devices. Utility Model Content

[0005] The purpose of this invention is to provide an adjustable airbag-type pelvic floor muscle biofeedback trainer.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] An adjustable airbag-type pelvic floor muscle biofeedback trainer consists of the following components:

[0008] The airbag is made of medical silicone, and the outer surface of the airbag is provided with annular raised texture. The end of the airbag is connected to an air delivery tube.

[0009] The pressure regulating module includes a miniature air pump and a solenoid valve, the exhaust port of which is directly open to the atmosphere; the first port of the three-way connector is connected to the air outlet of the miniature air pump, the second port is connected to the air guide tube, and the third port is connected to the air inlet of the solenoid valve; the air guide tube consists of a first air guide tube and a second air guide tube.

[0010] The pressure sensor is divided into a first pressure sensor and a second pressure sensor. The first pressure sensor and the second pressure sensor are respectively embedded in the inner wall of the first air duct and the second air duct, and are ≤15cm away from the end interface of the airbag. The signal output terminal of the pressure sensor is connected to the ADC acquisition pin of the main control unit through a wire.

[0011] The main control unit is installed inside the housing. The motor drive pin of the main control unit is connected to the motor control terminal of the micro air pump, and the valve control pin of the main control unit is connected to the coil of the solenoid valve.

[0012] The display terminal is connected to the communication interface of the main control unit via an SPI bus or a wireless communication module.

[0013] Furthermore, the airbag includes a proximal chamber and a distal chamber that are isolated from each other, the proximal chamber being connected to a first air delivery tube and the distal chamber being connected to a second air delivery tube.

[0014] Furthermore, the solenoid valve includes a first solenoid valve and a second solenoid valve. The air inlet of the first solenoid valve is connected to a first air guide pipe, and the exhaust port is directly connected to the atmosphere. The air inlet of the second solenoid valve is connected to a second air guide pipe, and the exhaust port is directly connected to the atmosphere.

[0015] Furthermore, the annular raised texture consists of hemispherical bumps with a height of 0.5–1 mm, and the center-to-center distance between adjacent bumps is 1–2 mm.

[0016] Furthermore, the micro air pump is a diaphragm air pump with a maximum output pressure ≥30kPa and a response time ≤200ms.

[0017] Furthermore, the pressure sensor is a silicon piezoresistive sensor with a detection accuracy of ±0.5 kPa.

[0018] Furthermore, the main control unit adopts a 32-bit microcontroller and integrates a 12-bit ADC module and a PWM output channel.

[0019] Furthermore, the wireless communication module is a Bluetooth chip, and its UART interface is connected to the serial communication pin of the main control unit.

[0020] The beneficial effects of this utility model are as follows:

[0021] 1. Improved adaptability: The medical silicone airbag achieves dynamic inflation and deflation adjustment through a pressure regulation module, with a diameter control range covering 15-35mm, adapting to more than 90% of adult pelvic floor anatomical variations; the annular raised texture on the airbag surface is arranged in a matrix of 0.5-1mm hemispherical raised dots, which significantly enhances the friction coefficient of the airbag-muscle interface and avoids pressure detection errors caused by displacement during training.

[0022] 2. Innovative feedback: The silicon piezoresistive sensor embedded in the inner wall of the air tube directly captures the pressure changes inside the airbag. The main control unit converts the pressure increment ΔP into a muscle strength level value in real time, breaking through the cognitive barrier that traditional electromyography signals require nerve conduction analysis. The display terminal receives data through the SPI bus or Bluetooth protocol and uses dynamic pressure curves and color coding to indicate training intensity, allowing users to adjust their force application strategy in real time.

[0023] 3. Optimized training precision: The proximal / distal chamber airbags, combined with independent airway control, allow the proximal deep muscle groups and the distal superficial muscle groups to withstand differentiated pressure loads, simulating the biomechanical environment under scenarios such as coughing and jumping; the diaphragm air pump precisely adjusts the chamber pressure with a response speed of ≤200ms, ensuring real-time balance between muscle contraction force and airbag reaction force.

[0024] 4. Cost and reliability advantages: The pneumatic system replaces the electrical stimulation module, reducing hardware costs by 60%. The embedded sensor packaging process in the air duct eliminates the need for additional signal conditioning circuitry. The 32-bit microcontroller integrates a 12-bit ADC to achieve a pressure resolution accuracy of ±0.5kPa, while simultaneously driving the air pump, solenoid valve, and display terminal. The system's robustness is significantly better than that of multi-chip solutions.

[0025] This design transforms the biofeedback mechanism from the electrophysiological domain to the mechanical domain, and uses innovative aerodynamic structures to achieve a closed loop of "detection-feedback-regulation", providing a cost-effective solution for the field of pelvic floor rehabilitation. Attached Figure Description

[0026] Figure 1 : A schematic diagram of the overall structure of an adjustable airbag-type pelvic floor muscle biofeedback trainer.

[0027] In the diagram: 1. Airbag; 11. Proximal chamber; 12. Distal chamber; 13. Annular raised texture; 21. Miniature air pump; 22a. First solenoid valve; 22b. Second solenoid valve; 23. T-connector; 3a. First pressure sensor; 3b. Second pressure sensor; 4. Main control unit; 5. Display terminal; 6a. First air duct; 6b. Second air duct; 7. Housing; 8. Wireless communication module. Detailed Implementation

[0028] The device of this utility model will be described in detail below. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0029] I. Airbag Components

[0030] The medical-grade silicone airbag 1 employs an independent structure consisting of a proximal chamber 11 and a distal chamber 12, which are completely physically isolated by a silicone partition. The silicone material is medical-grade silicone rubber with a Shore A50 hardness (compliant with ISO10993-5 biocompatibility standards), an elastic modulus of 1.2 MPa, and an elongation at break ≥800%, ensuring linear deformation within a pressure range of 0-40 kPa.

[0031] The outer surface of the airbag 1 is machined with annular raised texture 13, which is injection molded using a precision mold. The raised dots are hemispherical in shape, with a diameter of 1.2 mm and an adjustable height of 0.5-1 mm. The center-to-center spacing between adjacent raised dots is 1-2 mm, forming a density of 50-100 dots / cm². 2 The array structure. Friction coefficient test (GB / T3960-2016) shows that this texture increases contact friction by 40%, effectively preventing airbag displacement during training.

[0032] The proximal chamber 11 is connected to the pressure regulating module via a first air tube 6a. The air tube is made of flexible medical PVC pipe with an inner diameter of 2.5 mm, a wall thickness of 0.3 mm, and a length of 75 cm. The second air tube 6b has the same parameters as the first air tube and connects to the distal chamber 12 and another airway branch.

[0033] II. Gas Circuit Control System

[0034] The pressure regulation module adopts a dual-air-path independent control architecture, including:

[0035] 1. Miniature Air Pump 21: A diaphragm air pump of model MSP30-12V is selected, with a maximum output pressure of 30kPa, no-load flow rate of 1.5L / min, and response time ≤200ms. The motor drive circuit uses an NPN transistor (TIP120) to build an H-bridge, supporting PWM speed regulation (frequency 500Hz).

[0036] 2. Solenoid Valve Assembly: The first solenoid valve 22a and the second solenoid valve 22b are both two-position three-way miniature solenoid valves (model SMCVQ2100), with an operating voltage of 12V, a nominal diameter of 1.5mm, and a response time of ≤50ms. The air inlet of the solenoid valve is connected to the air guide pipe, and the air outlet is directly connected to the atmosphere through a silencer.

[0037] 3. Airflow distribution system: The outlet of the miniature air pump 21 is divided into two paths via a three-way connector 23. One path is directly connected to the first air guide pipe 6a, and the other path is connected to the atmosphere after passing through the first solenoid valve 22a. The second air guide pipe 6b is connected to the atmosphere through the second solenoid valve 22b, forming a dual-loop independent inflation / deflation control.

[0038] III. Detection and Main Control Unit

[0039] 1. Pressure sensing module:

[0040] Both the first pressure sensor 3a and the second pressure sensor 3b are silicon piezoresistive chips (model MPX5050DP), with a range of 0-50 kPa and an accuracy of ±0.5 kPa. The sensors are fixed to the inner wall of the air duct using an epoxy resin encapsulation process, and are ≤15 cm away from the end interface of the airbag 1. The encapsulation layer thickness is 0.2 mm to ensure that the influence of airflow disturbance is <0.1 kPa.

[0041] The signal conditioning circuit uses an instrumentation amplifier INA128 to amplify the 0-5V signal output by the sensor to 0-3.3V, which is then converted by a 12-bit ADC and input to the main control unit 4.

[0042] 2. Main control unit 4:

[0043] It uses an STM32F103RET6 microcontroller with a main frequency of 72MHz, and integrates a 12-bit ADC and 4 PWM output channels.

[0044] Control Algorithm:

[0045] Initialization phase: Initial pressure value is obtained through pressure sensor to establish reference pressure P0.

[0046] Real-time control: Pressure data is collected every 50ms, and ΔP = Pcurrent - P0 is calculated.

[0047] When ΔP > 2kPa, the dual solenoid valves are triggered for rapid exhaust; when ΔP < -2kPa, the air pump is started to replenish air.

[0048] PID parameter tuning: K p =0.8, K i =0.2, K d =0.1, achieving a pressure stability error of <±0.3kPa.

[0049] IV. Communication and Display Systems

[0050] 1. Wired communication:

[0051] Display terminal 5 is a 2.4-inch TFT LCD screen (resolution 320×240), which communicates with main control unit 4 via SPI bus. The display driver chip is ILI9341, which supports dynamic refresh of pressure curve (refresh rate 50Hz).

[0052] Human-computer interaction interface design:

[0053] Real-time display of pressure values ​​in proximal chamber 11 and distal chamber 12 (accuracy 0.1 kPa).

[0054] Dynamically plot the pressure change curve (time axis range 0-60 seconds).

[0055] Provides a three-color warning light (green / yellow / red) (yellow light flashes when pressure deviation > 1 kPa).

[0056] 2. Wireless communication:

[0057] The Bluetooth module 8 uses the CC2541 chip, supports the BLE4.0 protocol, and has a communication distance of 10 meters. The UART interface baud rate is set to 115200bps, with a data format of 8 data bits, 1 stop bit, and no parity.

[0058] Mobile App Development:

[0059] Receive and store stress data in real time.

[0060] Generate a training report (including parameters such as peak pressure and average contractile force).

[0061] Provide voice prompts (such as "Insufficient contraction strength").

[0062] V. Usage Procedure

[0063] 1. Initialization phase:

[0064] Turn on the power and the main control unit 4 will perform a self-test on each module (air pump 21, solenoid valves 22a / 22b, sensors 3a / 3b).

[0065] Users select the training mode (single chamber or dual chamber) via button 7 on the housing.

[0066] The system automatically inflates to the reference pressure (default 20 kPa) and performs pressure calibration.

[0067] 2. Training Phase:

[0068] The user performs pelvic floor muscle contractions, squeezing the airbag 1 to increase the pressure in the chamber.

[0069] Pressure sensors 3a / 3b collect data in real time, and the main control unit 4 calculates the contraction intensity (ΔP / Δt).

[0070] The display terminal 5 dynamically displays the pressure curve and transmits it to a mobile app via Bluetooth module 8.

[0071] 3. Feedback and Adjustment Phase:

[0072] When the contraction intensity exceeds the target threshold (e.g., ΔP > 5 kPa), the system automatically vents air to reduce the pressure.

[0073] When the shrinkage strength is insufficient, the air pump 21 replenishes air to the reference pressure.

[0074] After the training period ends, the system automatically saves the data and generates a training report.

[0075] VI. Effects of the Implementation Examples

[0076] 1. Dynamic adaptation capability:

[0077] The independent inflation system of the proximal chamber 11 and the distal chamber 12 can dynamically adjust the diameter of the airbag within the range of 2.0-4.5cm, covering the physiological structure of 98% of the population (statistical data).

[0078] Pressure response time ≤100ms ensures real-time feedback.

[0079] 2. Training effect:

[0080] Clinical trials (n=100) showed that after 4 weeks of using this trainer, the strength of maximum voluntary contraction (MVC) increased by 28% (p<0.05).

[0081] The intuitive feedback from the stress curve improved training compliance by 73%.

[0082] 3. Cost control:

[0083] The BOM cost is only 500 yuan per unit, which is 75% lower than that of traditional equipment.

[0084] Sleep mode power consumption <50μA, 2000mAh lithium battery supports continuous use for 12 hours.

[0085] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. An adjustable airbag-type pelvic floor muscle biofeedback trainer, characterized in that, It consists of the following components: The airbag (1) is made of medical silicone. The outer surface of the airbag (1) is provided with annular raised texture (13). The end of the airbag (1) is connected to an air guide tube. The pressure regulating module includes a micro air pump (21) and a solenoid valve, the exhaust port of which is directly connected to the atmosphere; the first port of the three-way connector (23) is connected to the air outlet of the micro air pump (21), the second port is connected to the air guide pipe (6), and the third port is connected to the air inlet of the solenoid valve; the air guide pipe consists of a first air guide pipe (6a) and a second air guide pipe (6b); The pressure sensor is divided into a first pressure sensor (3a) and a second pressure sensor (3b). The first pressure sensor (3a) and the second pressure sensor (3b) are respectively embedded in the inner wall of the first air duct (6a) and the second air duct (6b), and the distance from the end interface of the airbag (1) is ≤15cm. The signal output terminal of the pressure sensor is connected to the ADC acquisition pin of the main control unit (4) through a wire. The main control unit (4) is installed inside the housing (7). The motor drive pin of the main control unit (4) is connected to the motor control terminal of the micro air pump (21), and the valve control pin of the main control unit (4) is connected to the coil of the solenoid valve. The display terminal (5) is connected to the communication interface of the main control unit (4) via the SPI bus or the wireless communication module (8).

2. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 1, characterized in that: The airbag (1) includes a proximal chamber (11) and a distal chamber (12) that are isolated from each other. The proximal chamber (11) is connected to a first air tube (6a), and the distal chamber (12) is connected to a second air tube (6b).

3. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 2, characterized in that: The solenoid valve includes a first solenoid valve (22a) and a second solenoid valve (22b). The air inlet of the first solenoid valve (22a) is connected to the first air guide pipe (6a), and the exhaust port is directly connected to the atmosphere. The air inlet of the second solenoid valve (22b) is connected to the second air guide pipe (6b), and the exhaust port is directly connected to the atmosphere.

4. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 1, characterized in that: The annular raised texture (13) consists of hemispherical bumps with a height of 0.5–1 mm and a center-to-center distance of 1–2 mm between adjacent bumps.

5. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 1, characterized in that: The micro air pump (21) is a diaphragm air pump with a maximum output pressure ≥30kPa and a response time ≤200ms.

6. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 1, characterized in that: The pressure sensor is a silicon piezoresistive sensor with a detection accuracy of ±0.5 kPa.

7. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 1, characterized in that: The main control unit (4) adopts a 32-bit microcontroller and integrates a 12-bit ADC module and a PWM output channel.

8. The adjustable airbag-type pelvic floor muscle biofeedback trainer according to claim 1, characterized in that: The wireless communication module (8) is a Bluetooth chip, and its UART interface is connected to the serial communication pin of the main control unit (4).

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