Lower limb blood circulation promoting system and method based on physiological feedback self-adaption

Abstract

The invention provides a lower limb blood circulation promoting system and method based on physiological feedback self-adaption, and relates to the technical field of intelligent wearable. According to the scheme, a plurality of detachable independent flexible air bag units are integrated through a flexible wearable sleeve, and segmented sequential inflation and deflation in the axial direction of a leg are achieved in cooperation with a circulation air pressure module; the muscle pump effect is effectively simulated to push venous blood to flow back; meanwhile, the micro-current stimulation module outputs low-frequency pulse current to directly activate muscular tissues of the lower limbs and enhance the vasomotor function, and the warm physical therapy module provides partitioned controllable warm stimulation; a sensing monitoring module arranged in the system collects PPG blood flow signals before and after pressurization, the internal pressure of each air bag and the skin temperature in real time, and a control module calculates a venous return index based on pulse wave amplitude changes, so that the air pressure intensity and rhythm, the micro-current frequency and amplitude and the heating temperature are dynamically adjusted; cooperative self-adaptive regulation and control of three modes of air pressure, electrical stimulation and warming are achieved, and blood circulation of the lower limbs is promoted.

Description

Technical Field

[0001] This application relates to the field of smart wearable technology, and in particular to a system and method for promoting lower limb blood circulation based on physiological feedback adaptation. Background Technology

[0002] Modern lifestyles often lead to poor venous return in the lower limbs, along with leg soreness, coldness, numbness, and edema due to prolonged sitting, standing, or lack of exercise. Post-operative patients or those on long-term bed rest face a higher risk of thrombosis due to reduced muscle activity. Existing technologies, such as compression stockings, only provide static compression and cannot create a gradient pressure wave from the ankle towards the heart, resulting in limited effectiveness and potentially exacerbating insufficient arterial blood supply. While medical-grade pneumatic pumps can provide sequential pressure, they are bulky, noisy, and complex to operate, making them unsuitable for home use. Ordinary physiotherapy devices, such as heating pads or simple massagers, have limited functionality, non-adjustable airbags, uneven pressure coverage, and lack physiological feedback and dynamic adjustment capabilities. Furthermore, most products rely on manual settings and cannot automatically recognize leg shape, adaptively adjust pressure, control temperature, or coordinate with microcurrent stimulation, making it difficult to balance safety, convenience, and personalized therapeutic effects. Summary of the Invention

[0003] This application provides a lower limb blood circulation promotion system and method based on physiological feedback adaptation to solve one or more technical problems existing in the prior art, and at least provides a beneficial option or creates conditions that can dynamically adjust air pressure, temperature and microcurrent parameters according to the user's real-time physiological state to achieve personalized and precise lower limb blood circulation promotion.

[0004] On the one hand, this application provides a lower limb blood circulation promotion system based on physiological feedback adaptation, comprising: A flexible, wearable sleeve with multiple detachable, independent flexible airbag units connected along the leg axis. A circulating air pressure module, connected to each of the flexible airbag units, is used to perform segmented sequential inflation and deflation operations; A microcurrent stimulation module is integrated inside the sleeve and configured to output low-frequency pulse current to stimulate lower limb muscle tissue; The thermotherapy module includes a flexible graphene heating element embedded in the sleeve liner for providing zoned and controllable thermotherapy. The sensing and monitoring module includes a PPG blood flow sensor, a pressure sensor, and a temperature sensor, which are used to collect pulse wave amplitude values ​​before and after pressurization, internal pressure of each flexible airbag unit, and lower limb skin temperature in real time. The control module, connected to the circulating air pressure module, microcurrent stimulation module, thermotherapy module, and sensor monitoring module, is configured to: calculate the venous return index based on the pulse wave amplitude of the PPG blood flow sensor before and after pressurization, and dynamically adjust the operating parameters of the circulating air pressure module, microcurrent stimulation module, and thermotherapy module according to the venous return index, so as to achieve coordinated adaptive control of air pressure, electrical stimulation, and thermotherapy modes to promote blood circulation in the lower limbs.

[0005] Furthermore, each of the flexible airbag units has magnetic power contacts and communication contacts on its outer surface, and the control module has a corresponding permanent magnet and metal contact base; the control module automatically identifies the number of installed flexible airbag units and their arrangement order along the leg axis by detecting the conduction state of the contacts, and generates an appropriate sequential pressurization control strategy accordingly.

[0006] Furthermore, the circulating air pressure module includes a miniature silent air pump, a main air circuit pipeline, multiple normally closed solenoid valves, and a pressure relief unit; each of the flexible airbag units is connected to the main air circuit pipeline via a corresponding normally closed solenoid valve; the pressure relief unit is configured to trigger rapid venting when overpressure is detected or an emergency stop command is received.

[0007] Furthermore, the control module is configured to: drive the circulating air pressure module to apply trial inflation of each of the flexible airbag units at a pressure lower than the standard treatment pressure when treatment is initiated, and extract the pressure rise rate based on the pressure-time response curve collected by the pressure sensor; when the pressure rise rate deviates from the predetermined allowable range, automatically adjust the initial drive parameters of the miniature silent air pump to calibrate the kinetic characteristics of the subsequent inflation process.

[0008] Furthermore, the circulating air pressure module divides the plurality of flexible airbag units into three control areas along the leg axis, and each control area contains at least one of the flexible airbag units. The circulating air pressure module sequentially performs inflation, pressure holding, and pressure release operations on each of the control areas. Specifically, the first control area, located at the farthest end, is first inflated to the target pressure and maintained for 10 seconds. Then, the second control area begins to inflate while the first control area depressurizes simultaneously. Subsequently, the third control area is inflated while the second control area depressurizes, thereby forming a centripetal pressure gradient that propagates from the distal end of the limb to the proximal end.

[0009] Furthermore, the microcurrent stimulation module integrates a leakage protection circuit; when the leakage current in the output circuit exceeds 50µA or the electrode contact impedance rises abnormally, the leakage protection circuit cuts off the current output within 10ms; the output parameters of the microcurrent stimulation module include current intensity, frequency, and duty cycle, wherein the current intensity ranges from 300µA to 5mA, the frequency ranges from 3Hz to 100Hz, and the duty cycle ranges from 20% to 80%; the control module dynamically adjusts the output parameters according to the venous return index to match different treatment intensity requirements.

[0010] Furthermore, each heating zone of the thermotherapy module is independently controlled by the control module through pulse width modulation signals; the control module dynamically sets the target temperature of each heating zone according to the venous return index; the thermotherapy module is also equipped with a dual protection mechanism of hardware over-temperature switch and software temperature limiting logic to ensure that the local temperature does not exceed 45℃ and the temperature fluctuation is controlled within ±0.5℃.

[0011] Furthermore, the venous return index is obtained by normalizing the change in PPG pulse wave amplitude before and after pressure application; when the venous return index indicates a significant improvement in venous return, the control module automatically configures a lower intensity treatment parameter combination; when the venous return index indicates insufficient improvement, the control module automatically increases to a higher intensity treatment parameter combination, thereby achieving closed-loop adaptive adjustment based on physiological response.

[0012] On the other hand, this application provides a method for promoting lower limb blood circulation based on physiological feedback, applied to the aforementioned system for promoting lower limb blood circulation based on physiological feedback, comprising the following steps: In automatic operation mode, the physical configuration of the flexible airbag unit is identified based on the magnetic contact conduction information, and the effectiveness of the sleeve fitting the limb is determined by combining the initial pressure and temperature readings. After confirming that the fit is effective, the thermotherapy module is activated simultaneously to stabilize the local temperature at 36°C to 38°C, and the circulating air pressure module is driven to apply a trial inflation pressure lower than the standard treatment pressure to each of the flexible airbag units. The venous return index is calculated based on the signals of the PPG blood flow sensor before and after pressurization, and the corresponding treatment settings are selected according to the venous return index. The circulating air pressure module is coordinated to perform segmented sequential inflation and deflation, the microcurrent stimulation module outputs matching electrical stimulation parameters, and the thermotherapy module is adjusted to the target temperature. After the main treatment is completed, the circulating gas pressure module is driven to intermittently inflate and deflate with a rhythmic waveform lower than the main treatment pressure. At the same time, the microcurrent stimulation module is activated to output low-frequency pulse current to prolong the vasodilatory effect and consolidate the circulation improvement effect.

[0013] Furthermore, the method also includes: In manual operation mode, the system receives the operating parameters and duration of the circulating air pressure module, microcurrent stimulation module, and thermotherapy module set by the user through an external terminal. Safety monitoring is continuously performed during the treatment process, and the pressure of the flexible airbag unit, lower limb skin temperature, leakage current and electrode contact status are detected in real time. When any detection parameter exceeds the predetermined safety threshold, the power supply to the relevant functional module is immediately cut off, and an audible, visual, or wireless warning signal is triggered.

[0014] The beneficial effects of this application are as follows: This application provides a lower limb blood circulation promotion system based on physiological feedback and adaptation. Multiple detachable independent flexible airbag units are integrated through a flexible wearable sleeve. Combined with a circulating air pressure module, segmented sequential inflation and deflation along the leg axis are achieved, effectively simulating the action of a muscle pump to promote venous blood return. Simultaneously, a microcurrent stimulation module outputs low-frequency pulsed current to directly activate lower limb muscle tissue, enhancing vascular contraction and relaxation. A thermotherapy module utilizes flexible graphene heating pads embedded in the sleeve lining to provide zoned, controllable thermotherapy, further dilating blood vessels and reducing blood viscosity. The system's built-in sensing and monitoring module collects PPG blood flow signals, internal pressure of each airbag, and skin temperature in real time before and after pressurization. The control module calculates the venous return index based on changes in pulse wave amplitude, dynamically adjusting the air pressure intensity and rhythm, microcurrent frequency and amplitude, and heating temperature. This achieves synergistic adaptive regulation of air pressure, electrical stimulation, and thermotherapy, improving blood circulation efficiency while considering individual differences and safety, significantly enhancing the precision, comfort, and effectiveness of treatment. This application also provides a corresponding method, the beneficial effects of which are similar to those of the system, and will not be described in detail here.

[0015] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0017] Figure 1 This is a schematic diagram of the control principle of the lower limb blood circulation promotion system based on physiological feedback adaptation provided in this application; Figure 2 This is a schematic diagram of the inner side of the sleeve provided in this application; Figure 3 This is a schematic diagram of the inner side of the flexible airbag unit provided in this application; Figure 4 This is a schematic diagram of the outer side of the flexible airbag unit provided in this application; Figure 5 This is a schematic diagram illustrating the operating principle of the lower limb blood circulation promotion system based on physiological feedback adaptation provided in this application; Explanation of reference numerals in the attached diagram: 101 is the control module, 102 is the sensing and monitoring module, 103 is the circulating air pressure module, 104 is the microcurrent stimulation module, 105 is the thermotherapy module, 201 is the Velcro strap, 202 is the combination of the permanent magnet and metal contact base of the control module, 301 is the air inlet of the flexible airbag unit, 302 is the exhaust port of the flexible airbag unit, 303 is the inflatable airbag, and 401 is the combination of magnetic power contacts and communication contacts on the outer surface of the flexible airbag unit. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] The present application will be further described below with reference to the accompanying drawings and specific embodiments. The described embodiments should not be considered as limitations on the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0020] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0022] In modern society, with changing lifestyles and a faster pace of work, prolonged sitting, standing, and lack of regular exercise have become common phenomena, leading to increasingly prominent problems of lower limb blood circulation disorders. Many people frequently experience discomfort such as leg soreness, heaviness, coldness, numbness, and edema, and in severe cases, these can even develop into chronic venous insufficiency, deep vein thrombosis, and other diseases. This is especially true for postoperative recovery patients, stroke sequelae patients, those in intensive care, or those who are bedridden for extended periods. Due to significantly weakened or completely lost lower limb muscle pump function, venous blood return is highly dependent on external intervention. If circulation is not promoted in time, thrombotic events can easily occur, threatening life. Therefore, developing a safe, effective, convenient, and widely applicable lower limb circulation-promoting technology suitable for both home and clinical settings is of significant practical importance.

[0023] Currently, the main clinical methods for improving lower limb blood circulation include medical compression stockings, intermittent pneumatic compression therapy devices, and various physiotherapy instruments. Medical compression stockings attempt to mimic the squeezing effect of muscle contraction on veins by providing static pressure that decreases upwards from the ankle. However, their pressure is constant and cannot be dynamically changed, making it difficult to form an effective centripetal pressure wave, thus limiting their effect on promoting venous return. More importantly, for patients with lower limb arteriosclerosis or peripheral arterial disease, continuous compression may further reduce arterial blood supply, leading to increased limb ischemia and even causing skin necrosis or ulcers, posing significant contraindications and safety risks.

[0024] Intermittent pneumatic compression therapy (IPC) devices are a commonly used physical therapy method in hospitals. They utilize a multi-chamber balloon that inflates and deflates sequentially, creating a pressure gradient that propels venous blood back from the distal to the proximal end. While this technology has some efficacy in preventing thrombosis, existing devices generally suffer from problems such as large size, heavy weight, high noise levels, the need for external power supplies, and fixed operating interfaces. These limitations typically restrict their use to medical institutions, making them unsuitable for fragmented scenarios such as home rehabilitation, office breaks, or travel. Furthermore, most pneumatic pumps operate on preset programs and cannot adaptively adjust based on individual leg shape, blood flow status, or real-time physiological feedback, easily leading to pressure discomfort or insufficient treatment, resulting in poor user compliance.

[0025] There are also many common physiotherapy products on the market, such as heated leg braces, vibrating massagers, or single-chamber airbag massagers. These products have limited functions, often only providing localized heat or simple pressure, lacking a scientifically designed pressure gradient, and thus failing to effectively activate the calf muscle pump or promote deep venous return. Their airbag sizes are fixed, unable to adapt to different leg circumferences, resulting in uneven pressure distribution, and they lack any physiological monitoring mechanisms to determine the user's current circulatory status, let alone dynamically adjust parameters. While some products integrate electrical stimulation functions, the current output mode is fixed and not linked to blood flow feedback, posing a risk of overstimulation or ineffectiveness. Furthermore, most temperature control systems are open-loop designs, making precise temperature adjustment impossible and posing a risk of burns.

[0026] In summary, existing technologies for promoting lower limb circulation suffer from multiple shortcomings: First, they lack the ability to perceive individual physiological states in real time, hindering precise intervention; second, functional modules such as air pressure, electrical stimulation, and heat stimulation are isolated, failing to form a synergistic effect; third, the equipment is bulky, complex to operate, and lacks comfort, making long-term use difficult; and fourth, safety design is inadequate, particularly lacking intelligent identification and protection strategies for high-risk groups of vascular diseases. These problems severely restrict the widespread application of lower limb circulation promotion technology in home health management and chronic disease rehabilitation, necessitating a novel solution integrating flexible wearable devices, multimodal intervention, physiological feedback, and intelligent regulation.

[0027] To address the aforementioned issues, this application provides a lower limb blood circulation promotion system and method based on physiological feedback adaptation. This solution utilizes a flexible wearable sleeve structure, integrating multiple detachable independent flexible airbag units along the leg axis to achieve flexible adaptation and precise coverage for different leg shapes. The system integrates three functional modules: circulating air pressure, microcurrent stimulation, and thermotherapy. The circulating air pressure module performs segmented sequential inflation and deflation to simulate the physiological muscle pump effect; the microcurrent stimulation module outputs low-frequency pulsed current to directly activate lower limb muscle tissue; and the thermotherapy module provides zoned, controllable heat therapy through a flexible graphene heating pad embedded in the liner. Simultaneously, the system incorporates a multi-dimensional sensing and monitoring module composed of a PPG blood flow sensor, pressure sensor, and temperature sensor to collect pulse wave amplitude, airbag internal pressure, and skin temperature in real time before and after pressurization. The control module calculates the venous return index based on pulse wave changes and dynamically adjusts the operating parameters of each functional module, thereby achieving closed-loop collaborative adaptive control of air pressure intensity and rhythm, electrical stimulation frequency and amplitude, and heating temperature. This ensures individualization, safety, and comfort while enhancing the circulation promotion effect.

[0028] First, the lower limb blood circulation promotion system based on physiological feedback adaptive provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0029] Reference Figures 1 to 4 The lower limb blood circulation promotion system based on physiological feedback provided in this application includes a flexible wearable sleeve, a flexible airbag unit, a circulating air pressure module, a microcurrent stimulation module, a thermotherapy module, a sensing and monitoring module, and a control module.

[0030] In some embodiments of this application, the surface of the flexible wearable sleeve is connected to multiple detachable independent flexible airbag units along the leg axis. The flexible wearable sleeve is the basic carrier of this system, and its structural design fully considers ergonomics and daily use needs. It is made of soft, breathable, and elastic materials, allowing it to closely conform to the lower limb contours of different users without causing a feeling of restriction. The sleeve has multiple detachable independent flexible airbag units arranged along the leg axis. Each airbag unit can be flexibly replaced or its position adjusted according to the user's leg length, leg circumference, and local shape, thereby achieving precise coverage and personalized fit to key areas from the calf to the thigh. This modular design not only improves wearing comfort but also facilitates cleaning, maintenance, and local functional expansion. It also provides a physical basis for subsequent segmented sequential pressurization, effectively solving the problems of uneven pressure distribution or poor fit caused by the fixed size of traditional one-piece airbags.

[0031] In some embodiments of this application, the flexible wearable sleeve has three to six independent flexible airbag units with identical structures arranged along the leg axis, and each unit can be disassembled to flexibly adapt to different user needs. The sleeve adopts a three-layer composite structure: the outer layer is an elastic textile layer woven from elastic fibers such as nylon and spandex, providing basic tightness and resilience, effectively adapting to different calf circumferences and improving overall fit and wearing comfort; the middle airbag layer adopts a stretchable pleated sidewall design, equipped with an independent air intake channel and check valve, which can adapt to at least ±40% changes in leg circumference and leg length, meeting the needs of a wide range of body types from teenagers to the elderly, and from thin to obese; the inner layer is made of skin-friendly, breathable textile material with moisture-wicking function, and integrates core components such as microcurrent stimulation electrode pads, flexible graphene heating pads, NTC temperature sensors, pressure sensors, and PPG blood flow sensors on its inner side. Among them, the microcurrent stimulation electrode pads ensure high-fit low-frequency pulse output, the flexible graphene heating pads form a multi-zone thermotherapy unit, and multiple sensors work together to build a precise and real-time physiological state monitoring network.

[0032] In some embodiments of this application, the recirculating pneumatic module connects to each flexible airbag unit to perform segmented sequential inflation and deflation. As the core circulation-promoting execution unit, the recirculating pneumatic module is connected to each flexible airbag unit via tubing. It can sequentially inflate and deflate the airbags from the ankle to above the knee according to preset logic, forming a dynamically propelling pressure wave that simulates the rhythmic contraction of the gastrocnemius muscle pump during natural walking. This module supports multi-level pressure adjustment and various inflation / deflation sequence modes, which can be flexibly configured according to different user conditions or treatment goals. Compared to static compression stockings or massage devices with only localized vibration, segmented sequential inflation and deflation can more effectively compress the deep venous system, accelerate venous blood return to the heart, reduce the risk of blood stasis, and promote lymphatic circulation, thereby significantly improving symptoms of circulatory disorders such as lower limb edema and soreness.

[0033] The microcurrent stimulation module is integrated inside the sleeve and configured to output low-frequency pulsed current to stimulate lower limb muscle tissue. Integrated inside the sleeve and close to the skin surface, the module's function is to output low-frequency pulsed current within a safe range, directly acting on the lower limb muscle tissue and surrounding nerve endings. This electrical stimulation can induce rhythmic muscle contractions, further enhancing venous pump function, and simultaneously promoting local microcirculation expansion by activating vascular endothelial cells to release relaxing factors such as nitric oxide. For users who are bedridden for extended periods or have limited mobility, this module can maintain a certain level of muscle activity and hemodynamics without active movement, preventing muscle atrophy and thrombosis. Furthermore, the low-frequency pulsed current also has analgesic and fatigue-relieving effects, enhancing the overall user experience.

[0034] The thermotherapy module includes flexible graphene heating pads embedded in a sleeve liner to provide zoned, controllable thermal stimulation. Specifically, the module utilizes the excellent thermal conductivity, flexibility, and electrothermal conversion efficiency of graphene to achieve rapid and uniform heating with low power consumption. The module supports independent temperature control for each zone, allowing users to set appropriate temperatures based on the blood circulation status of different leg areas or their subjective feelings, preventing localized overheating or underheating. Thermal stimulation effectively dilates capillaries, reduces blood viscosity, accelerates blood flow, relieves muscle tension and spasms, and enhances tissue metabolism. Unlike simple heating products, this system's thermotherapy is not isolated but rather part of a three-modal synergistic intervention, working in conjunction with air pressure and electrical stimulation to optimize the overall circulation-promoting effect.

[0035] The sensing and monitoring module includes a PPG blood flow sensor, a pressure sensor, and a temperature sensor, which are used to collect pulse wave amplitude, internal pressure of each flexible airbag unit, and lower limb skin temperature in real time before and after pressurization, respectively. The sensing and monitoring module is the key perception layer for realizing intelligent feedback control, and it consists of the PPG blood flow sensor, pressure sensor, and temperature sensor. The PPG blood flow sensor optically detects the pulse wave signal under the skin of the lower limb in real time before and after pressurization, acquiring changes in pulse wave amplitude to reflect venous return efficiency; the pressure sensor is embedded inside each airbag to continuously monitor whether the actual applied pressure meets the set value, preventing over- or under-pressure; the temperature sensor is attached to the skin contact surface to track local skin temperature changes in real time, ensuring the safety of thermotherapy. These multi-dimensional physiological and equipment parameters are synchronously collected and transmitted to the control module, providing the system with real and dynamic user status feedback, which is the data foundation for realizing personalized adaptive control.

[0036] The control module connects to the circulating air pressure module, microcurrent stimulation module, thermotherapy module, and sensor monitoring module. It is configured to calculate the venous return index based on the pulse wave amplitude before and after pressurization using a PPG blood flow sensor, and dynamically adjust the operating parameters of the circulating air pressure module, microcurrent stimulation module, and thermotherapy module according to the venous return index. This achieves coordinated adaptive control of the three modes of air pressure, electrical stimulation, and thermotherapy to promote blood circulation in the lower limbs.

[0037] Specifically, the control module, acting as the intelligent central hub of the entire system, receives various real-time data from the sensor monitoring module and calculates the venous return index based on the difference in pulse wave amplitude before and after pressurization of the PPG signal. This index quantitatively characterizes the actual promoting effect of the current intervention on blood circulation. Based on this, the control module dynamically adjusts the inflation and deflation sequence, pressure intensity, and duration of the circulating air pressure module, the pulse frequency, amplitude, and waveform of the microcurrent stimulation module, and the heating temperature and duration of each area of ​​the thermotherapy module, ensuring that these three elements work synergistically rather than simply superimposed. This closed-loop adaptive mechanism ensures that the system always operates under the optimal parameter combination, maximizing the circulation-promoting effect while avoiding discomfort or risks caused by parameter rigidity, truly achieving safe, efficient, and personalized intelligent lower limb blood circulation management.

[0038] In some embodiments of this application, the control module uses an STM32F4 series microcontroller with high computing power and low power consumption as the main control unit. Leveraging its integrated multi-channel PWM output, high-precision ADC input, SPI high-speed data interface, and BLE Bluetooth communication interface, it achieves unified scheduling and precise control of the pneumatic actuator (composed of a miniature silent air pump and solenoid valve), the microcurrent stimulation circuit, the thermotherapy module (composed of a flexible graphene heating element), and various sensors. The control module continuously collects key physiological and equipment parameters, including real-time internal pressure of each airbag from the pressure sensor, skin temperature of each heating area from the NTC temperature sensor, blood flow pulse wave signal output from the PPG photoelectric sensor, and the operating status and electrode contact impedance of the microcurrent stimulation circuit. This data is then aggregated in real-time to the MCU for fusion analysis and dynamic processing, thereby continuously generating, optimizing, and updating personalized treatment parameter combinations adapted to the current user's blood circulation response, ensuring the entire intervention process is safe, efficient, and highly adaptive.

[0039] In some embodiments of this application, the MCU of the control module performs precise and coordinated closed-loop control of the pneumatic actuator, thermotherapy module, and electrical stimulation unit based on real-time processed physiological feedback parameters. For the pneumatic actuator, the MCU independently regulates the inflation, pressure holding, and depressurization sequence of each flexible airbag through multiple solenoid valves and an air pump drive circuit, ensuring that the segmented sequential pressurization is precisely advanced along the physiological path from distal to proximal. For the thermotherapy module, the MCU uses pulse width modulation to drive the MOSFET power regulation circuit, dynamically distributing power to the flexible graphene heating elements in each heating area, achieving zoned constant temperature control and maintaining a stable temperature within the set range. The three types of actuators operate collaboratively under a unified control logic, forming a three-in-one adaptive intervention system of pneumatic propulsion, electrical stimulation activation, and thermotherapy relaxation, significantly improving the overall efficacy and individual adaptability of lower limb blood circulation promotion.

[0040] In some embodiments of this application, users can intuitively view key parameters during the current treatment process via an app connected to the control module via Bluetooth. These parameters include the pressure values ​​of each balloon, the temperature of the heating area, the microcurrent output intensity, and the venous return improvement index calculated based on PPG signals. Users can also manually adjust the pressure intensity, heating temperature, and electrical stimulation intensity according to their own experience, flexibly customizing personalized intervention plans. Simultaneously, users can choose to enable automatic treatment mode, where the system autonomously analyzes blood circulation status based on real-time collected physiological data and dynamically matches the optimal trimodal synergistic treatment parameters, achieving truly intelligent adaptive intervention. To further enhance the long-term value of the device, the control module also supports over-the-air firmware upgrades, allowing for remote updates of core algorithms, security strategies, or new functional modules via wireless means. This ensures continuous system optimization and evolution, maintaining technological advancement and functional expandability.

[0041] In some embodiments of this application, each flexible airbag unit has magnetic power and communication contacts on its outer surface, while the control module is equipped with a corresponding permanent magnet and metal contact base. This design has significant functional value and user experience benefits. The magnetic structure enables rapid electrical connection and signal interaction between the control module and each flexible airbag unit, simplifying the assembly process and significantly improving the system's modularity and ease of use. Users can freely choose to install different numbers of airbag units according to their leg length or treatment needs, without complex wiring or manual configuration. Simply placing the control module near the airbag unit will automatically attract it and establish a stable and reliable electrical path.

[0042] More importantly, the MCU in the control module can detect the conduction status of each contact point and identify in real time the total number of currently installed flexible airbag units and their specific arrangement along the leg axis, thereby accurately determining the user's lower limb coverage and anatomical features. Based on this identification result, the system can automatically generate a matching sequential pressurization control strategy, such as determining the inflation start position, pressure gradient direction, segment timing, and duration of each segment, ensuring that the pressure wave always effectively propagates from the distal to the proximal end, conforming to the physiological venous return path. This design avoids pressure sequence disorder or localized ineffective pressurization caused by incorrect airbag number or placement, fundamentally improving the scientific nature and individual adaptability of the treatment, while laying the hardware foundation for future expansion of more functional modules or adaptation to different limb sites.

[0043] In some embodiments of this application, the circulating air pressure module adopts an integrated design of a miniature silent air pump, a main air pipeline, multiple normally closed solenoid valves, and a pressure relief unit. This structure ensures system performance while also considering safety, accuracy, and user experience. The miniature silent air pump, as the core air source, is compact and operates with extremely low noise, making it suitable for scenarios requiring a quiet environment, such as homes, offices, or nighttime use, avoiding the disruption to users' rest or daily activities caused by the high-decibel operation of traditional air pumps. The main air pipeline, as the main gas transmission backbone, efficiently distributes compressed air to various branch control nodes, ensuring a stable airflow supply.

[0044] Each flexible airbag unit is connected to the main air pipeline through an independent normally closed solenoid valve. This one-to-one control method enables the system to perform precise and independent inflation timing management for each airbag, achieving true segmented sequential pressurization. The normally closed design ensures that all airbags remain closed in the power-off or standby state, preventing gas leakage from causing pressure failure, while improving energy utilization efficiency and system response speed.

[0045] Crucially, the system's pressure relief unit is configured to immediately trigger a rapid venting mechanism when internal pressure exceeds a safety threshold or an emergency stop command is received. This quickly releases all compressed gas from the airbags, preventing limb compression injuries or user discomfort caused by abnormally high air pressure. This safety feature not only complies with medical-grade device safety standards but also significantly enhances user confidence and reliability during extended or unattended use, ensuring the entire circulating pneumatic system operates efficiently while remaining in a controllable, interruptible, and emergency-safe state.

[0046] In some embodiments of this application, the system uses a miniature silent air pump with a rated voltage of 5V as a unified air supply source. Its outlet is connected to the main air pipeline after being processed by a pressure stabilizing and buffering structure. The main air pipeline branches into several parallel branches near the main control module. Each branch is connected in series with a normally closed miniature solenoid valve, thereby realizing independent start-stop control and inflation flow regulation of the corresponding airbag segment. This ensures that under a single air source condition, multiple airbags can still be finely driven according to a preset range and precise timing, simulating the physiological pressure wave that propagates from the ankle to the thigh.

[0047] To achieve high-precision closed-loop pressure control, the system deploys miniature pressure sensors with a range of 0-300 mmHg at key nodes in the main pipeline and each airbag branch. These sensors collect real-time data on the pipeline supply pressure and the instantaneous pressure values ​​inside each airbag segment, feeding the data back to the MCU to provide dynamic support for its pressure curve tracking algorithm and safety pressure limiting strategy. Furthermore, each airbag segment has an integrated miniature pressure relief valve or dedicated pressure relief channel at its end. During routine treatment, these valves are used for periodic deflation and complete emptying. Upon detecting overpressure, pressure sensor failure, or a user-triggered emergency stop command, they can immediately execute a rapid pressure relief action, quickly releasing local pressure and effectively reducing the risk of pressure injury to limb tissues. This significantly improves the overall safety and operational reliability of the system in long-term or unattended use scenarios.

[0048] In some embodiments of this application, the control module is configured to drive the circulating air pressure module to apply a trial inflation pressure lower than the standard treatment pressure to each flexible airbag unit upon treatment initiation, and to extract the pressure rise rate based on the pressure-time response curve collected by the pressure sensor. This design has important implications for adaptive calibration and safety assurance. Due to differences in factors such as leg circumference, muscle tension, tightness of clothing, and ambient temperature among different users, even when using the same air pump and solenoid valve, the rate at which the internal pressure of each airbag builds up during actual inflation may vary significantly. If standard treatment pressure inflation is directly applied using preset parameters, some users may experience discomfort due to excessively rapid inflation, or insufficient inflation may fail to achieve an effective circulation-promoting effect.

[0049] To address this, the system introduces a low-intensity exploratory inflation phase before formal treatment. High-precision pressure sensors record the pressure-time changes of each airbag in real time from the start of inflation to the target exploratory pressure, calculating the pressure rise rate—a key kinetic indicator. This rate directly reflects the current airway system's flow resistance, airbag sealing status, and limb reaction characteristics. When the pressure rise rate of an airbag is detected to be significantly higher or lower than the preset allowable range, the control module determines that the current air pump output or pipeline status deviates from ideal operating conditions. It then automatically adjusts parameters such as the initial drive voltage, duty cycle, or start-stop rhythm of the miniature silent air pump to dynamically calibrate the kinetic characteristics of the subsequent formal inflation process.

[0050] This closed-loop pre-adjustment mechanism based on measured response ensures that the system can accurately achieve the set treatment pressure curve under safe and comfortable conditions, regardless of individual differences among users. This not only improves the consistency and reliability of treatment, but also effectively avoids performance drift caused by mechanical aging, tubing micro-leakage, or wearing deviations, making the entire pneumatic intervention process truly intelligent, personalized, and highly robust.

[0051] In some embodiments of this application, the circulating air pressure module divides multiple flexible airbag units into three control areas along the leg axis. Each control area contains at least one flexible airbag unit. This partitioning design aims to accurately simulate the physiological mechanism of the gastrocnemius muscle pump and femoral vein return during natural human walking, thereby efficiently promoting centripetal venous blood return in the lower limbs.

[0052] Specifically, the system uses time-series control to sequentially inflate, maintain, and depressurize three zones: the first control zone, located furthest out, is inflated to the set target pressure and maintained for 10 seconds. This effectively compresses the deep veins in the ankle and lower leg, pushing stagnant blood upwards. Subsequently, as the second control zone begins inflating, the first control zone simultaneously depressurizes, rapidly restoring blood flow to the compressed area and preventing local ischemia caused by prolonged compression. Then, as the third control zone begins inflating, the second control zone simultaneously depressurizes, creating a continuous, unidirectional pressure wave advancing from the distal to the proximal end of the limb. This dynamic relay-style sequential pressurization pattern not only conforms to the anatomical characteristics of unidirectional venous valves but also effectively prevents blood backflow and significantly improves venous return efficiency.

[0053] Meanwhile, the 10-second pressure holding time has been optimized through clinical experience, ensuring sufficient blood is pushed back to the heart while avoiding discomfort or tissue damage caused by prolonged pressure holding. By dividing the balloon unit into three logical regions according to function and implementing precise timing coordination, the system achieves a highly biomimetic circulatory support effect under limited hardware conditions, balancing therapeutic efficacy, physiological rationality, and user comfort. It provides a scientific and reliable physical intervention for preventing deep vein thrombosis, alleviating chronic venous insufficiency, and improving postoperative lower limb circulation.

[0054] Therefore, the above-mentioned segmented air pressure control and adaptive strategy aims to automatically adjust the pressurization speed and holding time of each segment of the airbag according to the user's soft tissue pressure characteristics, while ensuring safety, so as to obtain a pressure curve that better meets individual comfort and venous return requirements.

[0055] In some embodiments of this application, after the system is started and wear detection is completed, the control module first sets the target pressure for each airbag according to the treatment level selected by the user (low, medium, high, and off). The low-end setting is labeled "Gentle Care," the medium-end setting is labeled "Standard Circulation Promotion," and the high-end setting is labeled "Rapid Return Promotion." The lower leg is divided into three sections: the first control area is the ankle, the second control area is the middle of the lower leg, and the third control area is the upper part of the lower leg. Detailed pressure parameters are shown in Table 1 below.

[0056] Table 1 Target pressure values ​​at different locations

[0057] After inflation stops, if the pressure of any section of the airbag exceeds the upper limit of the target range, open the deflation valve until the pressure value is within the target range. If the pressure of any section of the airbag exceeds the set range and remains so for more than 10 seconds, the system will immediately trigger an alarm and display a "Pressure Too High" message on the APP interface.

[0058] When the device is first powered on and inflated, the control module performs a trial inflation, determining the inflation volume and speed based on the user's individual physical condition. The system will drive each airbag to slowly rise from near-zero pressure at a low pressurization rate. Real-time recording of pressure-time curves By analyzing the curve, the following two key characteristic parameters were extracted: (1) the rate of pressure rise. : Calculated within a preset pressure range get , The larger the value, the shorter the time required for the same pressure increment, the stiffer the lower limb muscle tissue as a whole, and the relatively poor tolerance to rapid pressure increase; (2) Pressure stabilization time This refers to the period from the start of inflation until the pressure first stabilizes at the target value. The time taken reflects the degree of fit between the airbag and the local limb. A longer length usually indicates that the airbag needs more time to conform to the limb, and there is more compressible space. If the duration is too long, the user will be reminded to recheck the wearing of the device to rule out any weakening of the treatment effect due to improper wearing. A shorter length indicates a good fit between the airbag and the limb, resulting in higher pressure transmission efficiency. Furthermore, It is also used to indicate the estimated completion time of the entire treatment process to the user.

[0059] According to parameters Adjust the air pump speed This allows for adjustment of the inflator pressure ramp rate and pressurization rhythm at each stage of treatment. For different treatment levels, the system presets a set of target pressure ramp rate ranges. The values ​​are set as follows: low setting: L=3 mmHg / s, H=6 mmHg / s; medium setting: L=4 mmHg / s, H=8 mmHg / s; high setting: L=5 mmHg / s, H=10 mmHg / s. The control module continuously calculates the current... Deviation from the target range, and based on the deviation... Perform closed-loop regulation. When When the system determines that the pressure is applied too quickly, in order to avoid instantaneous compression of the soft tissue, the control module automatically reduces the pump speed according to the deviation range, adjusting it according to the following formula (1): (1); In formula (1), For the current speed, For the updated rotational speed, As a deceleration proportional coefficient, a value of 0.5 is set to ensure that the pressure rise slope returns to the target range. When If the system determines that the pressurization is too slow, increase the pump speed within a safe range and adjust it according to the following formula (2): (2); In formula (2), This is the acceleration factor, set to 0.3, to shorten the time required to reach the target pressure. If... In and In between, the system maintains Basically unchanged.

[0060] By using the pump speed as the core adjustment factor and the adaptive control strategy described above, this invention eliminates the need for users to manually set complex parameters, enabling efficient and comfortable intervention for venous return obstruction and leg fatigue under safe and controllable conditions during use.

[0061] After each airbag is inflated, it must maintain a constant pressure according to preset parameters. By simulating the physiological rhythm of skeletal muscle contraction and relaxation, a gradient pressure field is constructed, thereby driving venous blood to return to the heart. This strategy, through the sequential alternating inflation and deflation design of the airbags, achieves continuous pressure transmission to different sites of action, maximizing venous return efficiency while ensuring human comfort, and ensuring the scientific and effective operation of the system.

[0062] In some embodiments of this application, a microcurrent stimulation module is used to provide low-intensity, physiological-level electrical stimulation during pneumatic circulation promotion to improve local microcirculation, enhance calf muscle pump function, and promote soft tissue metabolism. This module consists of a microcurrent generating circuit, a constant current control unit, a leakage protection unit, an electrode contact detection unit, a skin impedance acquisition circuit, and an electrode assembly. The integrated multiple functional units ensure the safety and effectiveness of the electrical stimulation. The microcurrent generating unit uses a combination of a low-power DAC waveform generation chip and a constant current source drive circuit, enabling precise adjustment of the output waveform, frequency, and current amplitude. This provides gentle stimulation to superficial muscle groups such as the gastrocnemius, soleus, and tibialis posterior muscles, effectively activating the muscle pump function.

[0063] In some embodiments of this application, two sets of metal electrode contacts that directly contact the skin are arranged along the leg axis on the inner side of each airbag. Each electrode contact consists of a pair of conductive bumps, ensuring that effective microcurrent output and circuit closure can be achieved through the skin surface after wearing. These electrode contacts are made of medical-grade stainless steel, with rounded corners and polished surfaces to form a micro-arc or hemispherical protrusion structure, which not only increases the effective contact area but also avoids pressure or scratches that sharp edges may cause to the skin. The connection between the electrode contacts and the internal circuit of the airbag is fully encapsulated with a medical-grade polytetrafluoroethylene insulating layer to prevent the possibility of current leakage to non-contact areas.

[0064] In some embodiments of this application, the microcurrent stimulation module integrates a highly sensitive leakage protection circuit, a design that plays a crucial role in ensuring user safety. Since the microcurrent acts directly on human skin and muscle tissue, any abnormal leakage or poor electrode contact could cause stinging, burns, or even more serious risks of electric shock.

[0065] To address this, the system is designed so that when the leakage current in the output circuit exceeds 50 µA or the contact impedance between the electrode and the skin abnormally increases, the leakage protection circuit can quickly cut off the current output within 10ms. This effectively prevents safety hazards caused by unexpected situations such as equipment failure, dried sweat, electrode detachment, or skin damage. This response speed is much faster than the human nerve perception threshold, ensuring that the user is out of danger before experiencing any discomfort or even slight pain, thus meeting the safety specifications for medical electronic devices.

[0066] Meanwhile, the output parameters of the microcurrent stimulation module are precisely limited to a safe and effective range. The current intensity can be adjusted between 300 µA and 5 mA, which can activate motor nerves to induce muscle contraction while avoiding pain or tissue damage. The frequency range is set from 3 Hz to 100 Hz, covering low-frequency stimulation that promotes blood circulation to mid-to-high frequency range that relieves muscle fatigue. The duty cycle is adjustable between 20% and 80% to control the ratio of stimulation to interval time, preventing continuous muscle contraction that could lead to fatigue.

[0067] More importantly, these parameters are not fixed but dynamically optimized and adjusted by the control module based on the real-time calculated venous return index. When the system detects that the current improvement in blood flow is weak, it can appropriately increase the current intensity or adjust the frequency to enhance the muscle pump effect; conversely, if the return index has reached the ideal level, it automatically reduces the stimulation intensity to maintain comfort. This closed-loop control mechanism based on physiological feedback enables microcurrent stimulation to have both therapeutic flexibility and precise matching to the individualized needs of different users at different stages, maximizing its synergistic therapeutic effect of promoting lower limb blood circulation while ensuring absolute safety.

[0068] In some embodiments of this application, the microcurrent stimulation module employs a multi-dimensional adjustment structure independent of the pneumatic pressure treatment level, allowing the electrical stimulation output to be independently controlled by its own parameter system, rather than limited by the overall pneumatic pressure level. Its adjustable parameters include three independent levels: current intensity, stimulation frequency, and pulse width. These are: Low level (microcurrent relief mode), with a current setting of 300 µA (maximum 500 µA), a frequency of 3 Hz, and a duty cycle of 20%, suitable for daily relief and inflammation improvement; Medium level (standard mode), with a current setting of 1 mA (maximum 2 mA), a frequency of 35 Hz, and a duty cycle of 50%, primarily used to increase venous flow and reduce swelling; and High level (high-frequency mode), with a current setting of 3 mA (maximum 5 mA), a frequency reaching 100 Hz, and a duty cycle of 80%, particularly suitable for quickly relieving symptoms of soreness and numbness. This flexible parameter adjustment mechanism allows the microcurrent stimulation module to provide personalized treatment plans according to the actual needs of different users, significantly improving the system's adaptability and user experience.

[0069] In some embodiments of this application, the thermotherapy module comprises a flexible heating unit, a temperature acquisition sensor, a constant temperature control circuit, a zone drive unit, and a temperature safety protection module. In terms of hardware structure, the system uses a low-power graphene film as the heating element, embedded in the skin-friendly inner lining of each airbag, ensuring the heat source is in close contact with the skin and is flexible and bendable. To achieve uniform heating and individualized adaptation, each heating area is equipped with an independent drive channel and paired with a high-precision NTC thermistor for real-time temperature sampling, feeding the data back to the main control MCU. All heating zones are controlled by pulse-width modulation signals output from the MCU, which are then precisely adjusted by a constant current and constant voltage drive chip, thereby achieving rapid heating, stable temperature control, and dynamic response. This allows the temperature of each zone to be independently maintained at a set target value based on physiological feedback, effectively improving the comfort, safety, and therapeutic synergy of thermotherapy.

[0070] In some embodiments of this application, each heating zone of the thermotherapy module is independently controlled by the control module via pulse width modulation (PWM) signals. This design enables precise management of temperature intervention in different parts of the lower limbs. Because users have individual differences in blood circulation, subcutaneous fat thickness, and sensitivity to heat stimulation in different parts of their legs, uniform heating often fails to balance therapeutic efficacy and comfort. Through PWM technology, the control module can continuously and steplessly adjust the power output of each heating zone, thereby precisely setting and maintaining its respective target temperature.

[0071] More importantly, these target temperatures are not fixed values, but are dynamically adjusted by the control module based on the venous return index calculated in real time: when a weak blood flow response is detected in a certain area, the system can appropriately increase the heating temperature of that area to dilate blood vessels, reduce blood viscosity, and enhance local microcirculation; conversely, if the return effect is good or the skin temperature is close to the upper limit, the heating intensity will be automatically reduced to avoid excessive heat stimulation.

[0072] To ensure safe operation, the system incorporates a dual protection mechanism: a hardware over-temperature switch and software temperature limiting logic. The hardware over-temperature switch acts as a physical safety barrier, forcibly cutting off power in extreme situations such as temperature sensor failure to prevent thermal runaway. The software temperature limiting logic continuously monitors the measured temperature of each area during normal operation, proactively reducing the pulse width modulation duty cycle once the temperature approaches the safety threshold. Through these two safeguards, the system strictly limits the local maximum temperature to below 45°C, effectively leveraging the thermotherapy's effects of promoting vasodilation and metabolism while avoiding low-temperature burns or skin discomfort.

[0073] Meanwhile, temperature fluctuations are controlled within ±0.5 ℃, ensuring stable and uniform thermal stimulation, significantly improving user comfort and long-term adherence. This thermotherapy design, which integrates dynamic regulation, zoned management, and multiple safety protections, transforms thermotherapy from an isolated auxiliary function into an intelligent intervention method that works in deep synergy with air pressure and electrical stimulation to optimize personalized blood circulation.

[0074] In some embodiments of this application, the system employs a high-precision closed-loop constant temperature algorithm for temperature control. Users can set target temperatures for each heating zone via an app. The system divides the target temperature into three levels: The first is low, with a target temperature locked at 36–38°C. This temperature range is close to the body surface temperature, gently activating the microcirculation of the superficial skin and subcutaneous tissue, accelerating the excretion of local metabolic waste, suitable for daily health care, post-operative recovery, or people with sensitive skin. The second is medium, with a target temperature set at 38–41°C. This temperature effectively promotes vasodilation in muscle tissue, increases blood flow and oxygen supply, and accelerates the absorption of inflammatory factors, suitable for relieving daily fatigue, mild muscle soreness, and joint discomfort. The third is high, with a target temperature controlled at 41–43°C. The high temperature can penetrate to deep muscle tissue, relaxing tense muscle fibers, relieving muscle spasms, and stimulating nerve endings to reduce pain, suitable for muscle recovery after exercise, chronic lumbar muscle strain, and other scenarios.

[0075] The temperature sampling period is 100ms, and the real-time measured temperature is MCU calculates temperature deviation in real time And adjust the PWM duty cycle according to the magnitude of the deviation: when High power output and rapid temperature adjustment; Time-linear power adjustment for smooth temperature control; when Maintain the current power while controlling fluctuations within ±0.5°C.

[0076] To ensure safety, this invention incorporates multiple temperature protection mechanisms: both hardware and software limits the maximum temperature to no more than 45°C; when a temperature rise rate is detected... Or the temperature remains higher than When the set time is exceeded, the system will immediately disconnect the power supply to the corresponding heating zone and issue a warning simultaneously via a buzzer and the APP; if an abnormality is found in the temperature sensor during the power-on self-test, the heating function will be locked and a "temperature sensor abnormality" message will be displayed to avoid the risk of loss of control.

[0077] In some embodiments of this application, the venous return index is obtained by normalizing the change in PPG pulse wave amplitude before and after pressurization. This design constitutes the core physiological basis for the intelligent closed-loop regulation of the entire system. PPG, or photoplethysmography, can non-invasively reflect the dynamic changes in blood volume in the subcutaneous microvascular bed. Its pulse wave amplitude usually increases significantly when venous return is improved because arterial perfusion efficiency is improved and microcirculation filling is enhanced after effective drainage of stagnant blood.

[0078] The system precisely acquires PPG signals at the same location before and after each barotrauma intervention, calculates the relative changes in amplitude between the two, and performs normalization processing to obtain a dimensionless, highly comparable, and robust venous return index that is robust to individual differences. This index objectively quantifies the actual promoting effect of the current treatment on blood circulation, avoiding blind interventions that rely on subjective feelings or fixed-time procedures.

[0079] When the index shows a significant improvement in venous return, it indicates that the current treatment intensity is sufficient or even potentially too high. The control module will then automatically configure itself to a lower intensity treatment parameter combination, such as reducing the cuff pressure, decreasing the microcurrent output intensity, or moderately lowering the heating temperature, in order to maintain the therapeutic effect while improving comfort and saving energy. Conversely, when the index indicates insufficient improvement, i.e., weak blood flow response or failure to meet the expected target, the control module will immediately increase to a higher intensity treatment parameter combination, enhancing pneumatic propulsion, increasing electrical stimulation to activate more muscle fibers, or raising the local temperature to further dilate blood vessels.

[0080] This dynamic feedback mechanism, based on real physiological responses, enables the system to perceive changes in the user's state in real time and adaptively adjust parameters within milliseconds to seconds, truly realizing a paradigm shift from "preset-based treatment" to "responsive intervention." This not only significantly improves the precision and individual adaptability of treatment but also effectively prevents the discomfort risks of overtreatment or the lack of efficacy due to undertreatment, providing users with a safe, efficient, and intelligent experience in promoting lower limb blood circulation.

[0081] In some embodiments of this application, based on a PPG blood flow sensor, the system measures the pulse wave amplitude before pressurization. The pulse amplitude after a certain segment of the airbag is inflated Calculate the venous return index ,in: when This indicates improved venous return, with higher values ​​indicating more significant improvement. Based on real-time... This invention designs a three-level adaptive treatment intensity strategy: when This indicates that the current pressurization strategy has significantly improved blood flow. The system selects a low level of pressure, temperature, and electrical stimulation to maintain a gentle rhythm and avoid overstimulation.

[0082] when This indicates that blood flow has improved to some extent but has not yet reached the optimal level. The system automatically switches to the medium level of pressure, temperature, and electrical stimulation, and appropriately increases the duration and rhythm density.

[0083] when This indicates that no effective improvement was observed. The system was then set to a higher level of pressure, temperature, and electrical stimulation, with extended hold time, increased pump speed, and shortened cycle intervals to enhance venous return stimulation.

[0084] By combining and With its dual feedback mechanism, this invention achieves adaptive optimization of holding time, pump speed, and treatment intensity, so that the pressurization action not only conforms to the mechanical properties of soft tissue, but also dynamically responds to real-time blood flow changes, thereby improving the overall circulation promotion effect.

[0085] Secondly, this application provides a method for promoting lower limb blood circulation based on physiological feedback, applied to the aforementioned system for promoting lower limb blood circulation based on physiological feedback, including the following steps.

[0086] Step S110: In automatic operation mode, the physical configuration of the flexible airbag unit is identified based on the magnetic contact conduction information, and the effectiveness of the sleeve fitting the limb is determined by combining the initial pressure and temperature readings.

[0087] In step S110, by detecting the conduction status of the magnetic power supply and communication contacts, the system can accurately determine the number of currently installed flexible airbag units and their arrangement order along the leg axis, thereby constructing a logical model consistent with the user's actual wearing structure. Based on this, the system further reads the initial pressure value inside each airbag and the initial temperature of the skin contact surface. If the pressure is close to atmospheric pressure and the temperature is close to room temperature, it indicates that the sleeve is not yet tightly attached to the limb; if the pressure is slightly higher than the ambient value and the temperature rapidly approaches body temperature, it indicates that it has been correctly worn. Only when the system confirms that the sleeve is effectively attached to the limb can risks such as pressure failure, local overheating, or poor electrode contact caused by airbag suspension, misalignment, or loosening be avoided. This intelligent identification and verification mechanism not only improves operational convenience, eliminating the need for users to manually input configuration information, but also fundamentally ensures the safety and effectiveness of subsequent treatments.

[0088] Step S120: After confirming that the fit is effective, the thermotherapy module is activated simultaneously to stabilize the local temperature at 36°C to 38°C, and the circulating air pressure module is driven to apply trial inflation to each flexible airbag unit at a pressure lower than the standard treatment pressure.

[0089] In step S120, ideal physiological preparation conditions are created for formal treatment, and system self-calibration is completed. Preheating the local temperature to a range of 36 to 38 degrees Celsius, close to the body's core temperature, helps dilate superficial blood vessels, reduce blood viscosity, and relieve muscle tension, thereby improving tissue sensitivity to subsequent pneumatic and electrical stimulation and enhancing user comfort. Simultaneously, the system performs low-intensity exploratory inflation, which avoids causing significant pressure while activating pressure sensors to collect pressure-time response curves for each airbag. This exploratory process assesses the current airway sealing, limb reaction force, and inflation dynamics, providing calibration data for precise application of treatment pressure. Through the coordinated activation of thermal pretreatment and pneumatic exploratory inflation, the system completes environmental adaptation and parameter pre-adjustment before formal intervention, significantly improving the stability and individual adaptation accuracy of the main treatment phase.

[0090] Step S130: Calculate the venous return index based on the signals from the PPG blood flow sensor before and after pressurization, select the corresponding treatment settings based on the venous return index, coordinate the circulatory pressure module to perform segmented sequential inflation and deflation, the microcurrent stimulation module to output matching electrical stimulation parameters, and the thermotherapy module to adjust to the target temperature.

[0091] In step S130, the system calculates the venous return index by comparing the changes in PPG pulse wave amplitude before and after pressurization. This index directly reflects the actual promoting effect of the current intervention on venous blood return. If the index shows significant improvement in return, a mild combination of treatment parameters is selected to maintain efficacy and improve comfort; if the improvement is insufficient, a higher-intensity multimodal intervention strategy is automatically activated. Based on this, the control module synchronously coordinates three functional modules: the circulating air pressure module performs precise sequential inflation and deflation from distal to proximal; the microcurrent stimulation module outputs current intensity, frequency, and duty cycle matched to the current blood flow state; and the thermotherapy module dynamically adjusts the temperature of each zone to the optimal level for microcirculation. These three modules no longer operate in isolation but form a synergistic intelligent intervention network under a unified physiological goal, ensuring that the treatment is both highly effective and safe, truly achieving personalized circulation promotion tailored to the individual, the time, and the effect.

[0092] In step S140, after the main treatment is completed, the driving circulation pressure module intermittently inflates and deflates with a rhythmic waveform lower than the main treatment pressure, while the microcurrent stimulation module is activated to output low-frequency pulse current to prolong the vasodilatory effect and consolidate the circulation improvement effect.

[0093] In step S140, although the main treatment has ended, the blood vessels are still dilated. If all interventions are suddenly stopped at this point, blood flow may rapidly decline or even cause temporary stasis. Therefore, the system transitions to a gentle termination phase, using low-pressure, low-frequency rhythmic pneumatic waves to simulate gentle muscle pump activity, maintaining continuous centripetal flow of venous blood. Simultaneously, the microcurrent stimulation module outputs low-frequency pulsed currents to continue gently activating muscle tissue and promoting the release of vasodilators such as nitric oxide from endothelial cells, further delaying vasoconstriction and prolonging the window for microcirculation improvement. This gradual exit strategy not only helps stabilize treatment results and prevent a "rebound effect" but also enhances the consistency and comfort of the user's overall experience, transforming the improvement in blood circulation from an instantaneous intervention into sustainable physiological regulation, laying the foundation for long-term health management.

[0094] In some embodiments of this application, reference is made to Figure 5In automatic mode, upon power-on, the control module first enters a system self-test process. The MCU will perform item-by-item checks on the temperature sensor, pressure sensor, PPG blood flow sensor, air pump, solenoid valve assembly, microcurrent stimulation circuit, and electrode contact impedance to confirm that each functional module is in a usable state. When the system detects an open circuit in the temperature probe, an abnormal zero point in the pressure sensor, loss of PPG signal, poor electrode contact, or abnormal air pump / solenoid valve drive, the device will immediately lock the corresponding function and prompt the user in the APP to prevent entering the treatment stage under abnormal conditions. After completing the self-test, the system enters the wearing structure recognition and fit detection process.

[0095] After self-testing, the control module detects the number of airbags currently installed and their arrangement along the leg using magnetic metal contacts on the main control module. The system confirms the actual configuration of the 3–6 airbag segments based on the conductivity of each contact and automatically establishes the corresponding sequential inflation model. Simultaneously, the control unit performs trial low-pressure inflation of each airbag segment at approximately 15–20 mmHg, recording the pressure rise curve and depressurization response to determine the fit between the airbag and the leg. Insufficient fit (manifested as unstable pressure or...) will be detected. If the fit is too long, the system will prompt the user to readjust the wearing; if the fit is normal, the treatment preparation stage will begin.

[0096] Before formal pressurization, the system first activates the thermotherapy module, raising the temperature of each heating zone to a soothing 36–38°C. The MCU performs closed-loop constant temperature control with a 100ms sampling period, ensuring a smooth heating process and maintaining temperature fluctuations within ±0.5°C. Simultaneously, the pressure module maintains a low-pressure probe at 15–20 mmHg to further measure the compressive characteristics of the user's soft tissues. The system records the rate of pressure increase. and pressure settling time Individualized pressure adjustment parameters are established. During this stage, the microcurrent stimulation module automatically sets to a low setting, providing mild electrical stimulation at 300 µA and 3 Hz to improve tissue compliance and enhance comfort during subsequent warming and pressurization procedures. This process lasts approximately 2 minutes to ensure the tissue reaches optimal pressure and heat treatment.

[0097] After tissue preheating, the system officially enters the sequential compression phase. The control module first collects pulse wave amplitude values ​​before and after pressurization using a PPG sensor to calculate the venous return index. The system is based on The value automatically determines the current treatment intensity level: when Run at low speed; Run at medium speed; Then, switch to the higher setting to increase pressure density and muscle pump stimulation intensity. The parameter values ​​for each setting are shown in Table 2 below.

[0098] Table 2 Parameter values ​​for each gear

[0099] In automatic mode, each airbag sequentially performs a "pressurization-holding-deflating" cycle according to its actual installation order along the leg axis, thereby forming a continuous, directional centripetal pressure wave to promote venous return. During the pressurization phase, the control module only opens the solenoid valve corresponding to the current segment, allowing gas from the air pump to enter that segment of the airbag. Pressure sensors continuously monitor changes in the internal pressure of the airbag; when the pressure reaches the target value for this treatment, the solenoid valve immediately closes, putting the airbag into a stable holding state. The holding phase maintains a short period of constant pressure, ensuring local tissue is compressed to achieve a physiological stimulation effect. During the deflation phase, the control module opens the depressurization channel of that segment of the airbag, rapidly reducing the internal pressure to near zero, allowing blood to flow naturally towards the proximal region after the external pressure is released. All airbags perform these actions segment by segment according to their actual arrangement in the device. During each pressurization phase, the control module monitors the pressure change curve in real time and adjusts accordingly. and The pressurization rate and pump speed are fine-tuned to match the pressurization rhythm with the user's soft tissue compliance. Simultaneously, the heating and microcurrent modules dynamically switch to the corresponding temperature zones and electrical stimulation parameters according to the intensity level, creating a synergistic therapeutic effect across the three modules. The system recalculates after each sequential cycle. This determines the treatment level for the next cycle, creating a closed-loop regulatory system based on improved blood flow. This phase lasts approximately 10 minutes.

[0100] After the sequential compression phase, the system automatically enters the deflation and reflow consolidation phase. During this phase, the pneumatic module ceases high-intensity propulsion and instead maintains venous return at a gentle rhythm of approximately 10 mmHg, preventing temporary backflow of blood caused by sudden release of external pressure. The microcurrent stimulation module switches to consolidation mode, using a low-frequency, sustained-release stimulation of 300uA at 3Hz to prolong the improved blood flow after treatment. Simultaneously, the heating module gradually lowers the temperature of the heated area to 36–38°C, improving user comfort and reducing the risk of skin fatigue. This phase typically lasts about 3 minutes, ensuring a smooth conclusion to the entire treatment process.

[0101] The entire automatic mode ends automatically after a full treatment session of approximately 15 minutes. The control module will execute the following steps in sequence: automatically depressurize each airbag to zero pressure; shut off the microcurrent output; gradually reduce the heating element power until the machine stops; and display a "Treatment Complete" message in the app. Simultaneously, the system will record key parameters from the entire treatment cycle, including... , , The gear position changes are recorded in internal storage for subsequent algorithm optimization or doctor analysis. If abnormal temperature, abnormal pressure, or sudden removal of the device by the user is detected during shutdown, the system will immediately enter protection mode to ensure the device terminates operation safely.

[0102] In some embodiments of this application, the method further includes the following.

[0103] (1) In manual operation mode, receive the operating parameters and duration of the circulating air pressure module, microcurrent stimulation module and thermotherapy module set by the user through an external terminal.

[0104] This design fully respects users' need for autonomous control, providing flexible operating space for users with specific treatment experience or personalized preferences. Users can freely adjust the intensity, mode, and duration of each functional module within preset safety limits via smartphones, tablets, or dedicated remote control devices. For example, they can choose combinations emphasizing different aspects such as pneumatic massage, electrical stimulation relaxation, or thermal soothing. This manual mode is not only suitable for healthy individuals who wish to customize their experience according to their own feelings, but also facilitates rehabilitation physicians in pre-configuring phased treatment plans for specific patients. Simultaneously, the system retains background validation of input parameters to ensure that all user settings are within medical safety boundaries, thus granting control without sacrificing basic safety, achieving a harmonious balance between professionalism and ease of use.

[0105] (2) Continuous safety monitoring is performed during the treatment process, and the pressure of the flexible airbag unit, the skin temperature of the lower limb, the leakage current and the electrode contact status are detected in real time. When any detection parameter exceeds the predetermined safety threshold, the power supply of the relevant functional module is immediately cut off and an audible and visual or wireless warning signal is triggered.

[0106] Specifically, this continuous monitoring mechanism is a key safeguard for ensuring safe use during extended periods, unattended operation, or in home environments. The system utilizes a built-in multi-dimensional sensor network to sample and analyze core operating parameters at the millisecond level: pressure sensors ensure that each airbag does not overpressurize due to solenoid valve malfunction or pump abnormalities; temperature sensors prevent localized overheating that could lead to low-temperature burns, especially important when the user is insensitive or asleep; leakage current monitoring circuits track the insulation integrity of the micro-current output circuit in real time, preventing the risk of electric shock due to sweat seepage, aging wiring, or electrode damage; and electrode contact status detection uses impedance measurement to determine whether the electrodes are properly fitting the skin, avoiding localized high-density current concentrations caused by poor contact. This real-time data not only helps in immediate risk identification but also provides auxiliary data for adaptive adjustment, enabling the system to maintain optimal treatment efficacy while ensuring safety.

[0107] Furthermore, this emergency response mechanism forms the final line of defense in the system's safety architecture, ensuring that any potential danger can be rapidly contained in its early stages. Once a dangerous signal is detected, such as an abnormally high airbag pressure, skin temperature exceeding 45 degrees Celsius, leakage current exceeding the 50µA limit, or a sudden increase in electrode impedance, the control module will forcibly shut down the power output of the corresponding functional module within 10 milliseconds, fundamentally eliminating the physical hazard source. Simultaneously, the device will activate an audible and visual alarm, such as a buzzer or flashing LED, to alert the user to the abnormal condition. If the device is connected to a mobile terminal or remote monitoring platform, it will also simultaneously send wireless alerts to notify caregivers to intervene. This multi-layered, multi-channel alarm strategy is suitable for immediate response by independent users and supports collaborative monitoring in remote health management scenarios, greatly improving the system's reliability and user trust in complex usage environments.

[0108] In addition, wireless alerts are pushed to the accompanying app on the user's mobile device via Bluetooth, ensuring that users or caregivers can be promptly notified of any abnormal conditions and take appropriate measures. Furthermore, the system performs a comprehensive self-test process every time it is powered on, sequentially checking the connectivity and functional integrity of each actuator, including the temperature sensor, pressure sensor, PPG blood flow sensor, electrical stimulation electrode circuit, air pump, solenoid valve, heating element, and current drive circuit. Only after confirming that all sensing and actuator components are in normal working order is the system allowed to enter treatment mode, thus fundamentally ensuring that the equipment always starts and operates in a safe and reliable state.

[0109] In some embodiments of this application, in manual mode, the system does not rely on automated adjustments, but allows users to independently set parameters for each functional module and runtime via a mobile app or main control interface. Manual mode aims to provide a high degree of user control, enabling users to choose suitable treatment combinations based on their individual needs, experience, or professional guidance.

[0110] The app interface provides four operation options for the device's three main functional modules—air pressure circulation, microcurrent stimulation, and thermotherapy—each with a high, medium, low, and off setting, and corresponding operation times ranging from 0 to 15 minutes. Users can independently select the setting and duration for each module on the interface, without being affected by other modules. For example, users can choose a custom combination of "low air pressure + medium microcurrent + high temperature," or completely disable a module and only run other treatment functions. All setting selections are achieved via button switching, making operation simple, and the user's settings remain unchanged throughout the manual mode; the system will not automatically change the set setting.

[0111] Despite the high degree of freedom offered by manual mode, the system continuously runs safety monitoring mechanisms in the background, including overpressure monitoring, overtemperature protection, electrode contact detection, abnormal skin impedance monitoring, current safety threshold monitoring, and battery level detection. When a detected value exceeds a preset threshold, the system will automatically depressurize, shut off heating, stop microcurrent stimulation, and prompt the user for adjustments via the app interface, ensuring that manual mode, while offering high freedom, still provides the same level of safety protection as automatic mode.

[0112] In summary, the lower limb blood circulation promotion system and method based on physiological feedback adaptation provided in this application have the following technical effects.

[0113] This solution achieves high adaptability and wearing comfort for different leg shapes through a flexible wearable sleeve and modular airbag design, solving the problem of uneven pressure distribution caused by the fixed size of traditional devices. By integrating three physical intervention methods—circulatory air pressure, microcurrent stimulation, and thermotherapy—and calculating the venous return index in real time based on PPG blood flow signals, the system can dynamically and collaboratively adjust the operating parameters of each module, forming a true multimodal closed-loop adaptive control, significantly improving the accuracy and individualization of the circulation-promoting effect.

[0114] The magnetic contact structure supports plug-and-play and automatic identification of the airbag unit, enabling the system to intelligently generate a sequential pressurization strategy based on the actual configuration, ensuring that the pressure wave always propagates along the physiological venous return direction. The circulating air pressure module uses a miniature silent air pump, normally closed solenoid valve, and rapid pressure relief unit, balancing high efficiency, low noise, and multiple safety guarantees; the microcurrent stimulation module integrates leakage protection and impedance monitoring, achieving effective neuromuscular activation within a safe range of 300 µA to 5 mA; the thermotherapy module uses pulse width modulation for independent temperature control, supplemented by a hardware over-temperature switch and software temperature limiting mechanism, to stably control the temperature within 45 ℃ with fluctuations not exceeding ±0.5 ℃, balancing therapeutic efficacy and skin safety.

[0115] The entire process encompasses fit detection, trial calibration, adaptive adjustment of the main treatment, and a gentle cleanup phase. It also supports user-defined operations in manual mode and implements millisecond-level safety monitoring and emergency shutdown throughout the entire process, ensuring safe, effective, and comfortable use in diverse scenarios such as home, rehabilitation, or prolonged bed rest. Ultimately, this system overcomes the limitations of existing technologies, such as isolated functions, lack of feedback, poor adaptability, and insufficient safety, achieving a substantial leap from passive intervention to intelligent, proactive, and personalized lower limb circulatory health management.

[0116] It should be noted that in all specific embodiments of this application, all data processing activities related to user identity or personal characteristics, such as user information, user behavior data, historical data, and location information, will be conducted in accordance with the principles of legality, legitimacy, and necessity. All data collection, use, storage, and processing will be subject to compliance with applicable national and regional laws, regulations, and industry standards, and informed consent from users will be obtained in a clear and explicit manner before processing. For the processing of sensitive personal information, separate consent from users will be obtained through prominent means such as pop-up prompts and independent confirmation pages. If any processing conflicts with laws and regulations, the laws and regulations will prevail, and necessary data processing will only be carried out within the scope permitted by laws and regulations, ensuring that all data-based applications, analyses, and technical implementations are conducted within the scope permitted by laws and regulations.

[0117] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this application are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0118] Furthermore, although this application is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding this application. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of ordinary skill of an engineer. Therefore, those skilled in the art can implement the application set forth in the claims using ordinary skill. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of this application, which is determined by the full scope of the appended claims and their equivalents.

[0119] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several programs to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0120] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable programs for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can retrieve and execute a program from or in conjunction with such a program execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can mean any means that can contain, store, communicate, propagate, or transmit a program for use by or in conjunction with a program execution system, apparatus, or device.

[0121] More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Additionally, computer-readable media can even be paper or other suitable media on which programs can be printed, for example, by optically scanning the paper or other media, then editing, interpreting, or, if necessary, processing it in a suitable manner to obtain the program electronically, and then storing it in computer memory.

[0122] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable program execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0123] In the foregoing description of this specification, the reference to terms such as "one embodiment / implementation," "another embodiment / implementation," or "certain embodiments / implementations," etc., indicates that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in an embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0124] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0125] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A lower limb blood circulation promotion system based on physiological feedback adaptation, characterized in that, include: A flexible, wearable sleeve with multiple detachable, independent flexible airbag units connected along the leg axis. A circulating air pressure module, connected to each of the flexible airbag units, is used to perform segmented sequential inflation and deflation operations; A microcurrent stimulation module is integrated inside the sleeve and configured to output low-frequency pulse current to stimulate lower limb muscle tissue; The thermotherapy module includes a flexible graphene heating element embedded in the sleeve liner for providing zoned and controllable thermotherapy. The sensing and monitoring module includes a PPG blood flow sensor, a pressure sensor, and a temperature sensor, which are used to collect pulse wave amplitude values ​​before and after pressurization, internal pressure of each of the flexible airbag units, and lower limb skin temperature in real time. The control module, connected to the circulating air pressure module, microcurrent stimulation module, thermotherapy module, and sensor monitoring module, is configured to: calculate the venous return index based on the pulse wave amplitude of the PPG blood flow sensor before and after pressurization, and dynamically adjust the operating parameters of the circulating air pressure module, microcurrent stimulation module, and thermotherapy module according to the venous return index, so as to achieve coordinated adaptive control of air pressure, electrical stimulation, and thermotherapy modes to promote blood circulation in the lower limbs.

2. The lower limb blood circulation promotion system based on physiological feedback adaptive as described in claim 1, characterized in that, Each of the flexible airbag units has magnetic power contacts and communication contacts on its outer surface, and the control module has a corresponding permanent magnet and metal contact base; the control module automatically identifies the number of installed flexible airbag units and their arrangement order along the leg axis by detecting the conduction state of the contacts, and generates an appropriate sequential pressurization control strategy accordingly.

3. The lower limb blood circulation promotion system based on physiological feedback adaptive as described in claim 1, characterized in that, The circulating air pressure module includes a miniature silent air pump, a main air circuit pipeline, multiple normally closed solenoid valves, and a pressure relief unit; each of the flexible airbag units is connected to the main air circuit pipeline via a corresponding normally closed solenoid valve; the pressure relief unit is configured to trigger rapid venting when overpressure is detected or an emergency stop command is received.

4. The lower limb blood circulation promotion system based on physiological feedback adaptive according to claim 1, characterized in that, The control module is configured to: drive the circulating air pressure module to apply trial inflation of each of the flexible airbag units at a pressure lower than the standard treatment pressure when treatment is initiated, and extract the pressure rise rate based on the pressure-time response curve collected by the pressure sensor; when the pressure rise rate deviates from the predetermined allowable range, automatically adjust the initial drive parameters of the miniature silent air pump to calibrate the dynamic characteristics of the subsequent inflation process.

5. The lower limb blood circulation promotion system based on physiological feedback adaptation according to claim 1, characterized in that, The circulating air pressure module divides the multiple flexible airbag units into three control areas along the leg axis, and each control area contains at least one of the flexible airbag units. The circulating air pressure module sequentially performs inflation, pressure holding, and pressure release operations on each of the control areas. Specifically, the first control area, located at the farthest end, is first inflated to the target pressure and maintained for 10 seconds. Then, the second control area begins to inflate while the first control area depressurizes simultaneously. Subsequently, the third control area is inflated while the second control area depressurizes, thereby forming a centripetal pressure gradient that propagates from the distal end of the limb to the proximal end.

6. The lower limb blood circulation promotion system based on physiological feedback adaptive according to claim 1, characterized in that, The microcurrent stimulation module integrates a leakage protection circuit; when the leakage current in the output circuit exceeds 50µA or the electrode contact impedance rises abnormally, the leakage protection circuit cuts off the current output within 10ms; the output parameters of the microcurrent stimulation module include current intensity, frequency, and duty cycle, wherein the current intensity ranges from 300µA to 5mA, the frequency ranges from 3Hz to 100Hz, and the duty cycle ranges from 20% to 80%; the control module dynamically adjusts the output parameters according to the venous return index to match different treatment intensity requirements.

7. The lower limb blood circulation promotion system based on physiological feedback adaptation according to claim 1, characterized in that, Each heating zone of the thermotherapy module is independently controlled by the control module through pulse width modulation signals; the control module dynamically sets the target temperature of each heating zone according to the venous return index; the thermotherapy module is also equipped with a dual protection mechanism of hardware over-temperature switch and software temperature limiting logic to ensure that the local temperature does not exceed 45℃ and the temperature fluctuation is controlled within ±0.5℃.

8. The lower limb blood circulation promotion system based on physiological feedback adaptation according to claim 1, characterized in that, The venous return index is obtained by normalizing the change in PPG pulse wave amplitude before and after pressurization. When the venous return index indicates a significant improvement in venous return, the control module automatically configures a lower intensity treatment parameter combination. When the venous return index indicates insufficient improvement, the control module automatically increases to a higher intensity treatment parameter combination, realizing closed-loop adaptive adjustment based on physiological response.

9. A method for promoting lower limb blood circulation based on physiological feedback adaptation, applied to the lower limb blood circulation promotion system based on physiological feedback adaptation as described in any one of claims 1 to 8, characterized in that, Includes the following steps: In automatic operation mode, the physical configuration of the flexible airbag unit is identified based on the magnetic contact conduction information, and the effectiveness of the sleeve fitting the limb is determined by combining the initial pressure and temperature readings. After confirming that the fit is effective, the thermotherapy module is activated simultaneously to stabilize the local temperature at 36°C to 38°C, and the circulating air pressure module is driven to apply a trial inflation pressure lower than the standard treatment pressure to each of the flexible airbag units. The venous return index is calculated based on the signals of the PPG blood flow sensor before and after pressurization, and the corresponding treatment settings are selected according to the venous return index. The circulating air pressure module is coordinated to perform segmented sequential inflation and deflation, the microcurrent stimulation module outputs matching electrical stimulation parameters, and the thermotherapy module is adjusted to the target temperature. After the main treatment is completed, the circulating gas pressure module is driven to intermittently inflate and deflate with a rhythmic waveform lower than the main treatment pressure. At the same time, the microcurrent stimulation module is activated to output low-frequency pulse current to prolong the vasodilatory effect and consolidate the circulation improvement effect.

10. The method for promoting lower limb blood circulation based on physiological feedback adaptation according to claim 9, characterized in that, The method further includes: In manual operation mode, the system receives the operating parameters and duration of the circulating air pressure module, microcurrent stimulation module, and thermotherapy module set by the user through an external terminal. Safety monitoring is continuously performed during the treatment process, and the pressure of the flexible airbag unit, lower limb skin temperature, leakage current and electrode contact status are detected in real time. When any detection parameter exceeds the predetermined safety threshold, the power supply to the relevant functional module is immediately cut off, and an audible, visual, or wireless warning signal is triggered.

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