An assisted exercise device for preventing bicep loss in ICU patients

Abstract

The application discloses an auxiliary exercise device for preventing biceps brachii loss of ICU patients, and relates to the technical field of medical rehabilitation and intensive care. The device is composed of a motion interaction device and a pneumatic control system, and is provided with a full-assistance and a half-assistance double training mode. The full-assistance mode can actively drive the patients in coma and without muscle strength to complete passive rehabilitation training of upper limbs, and the half-assistance mode can output adaptive impedance force according to the self-force output of the patients in low muscle strength, so that individual active resistance training is realized. The device can fully cover the bedside rehabilitation needs of patients in different muscle strength states, and the clinical adaptability and rehabilitation intervention effect are significantly better than those of the existing conventional rehabilitation technology. The device is suitable for special rehabilitation intervention of biceps brachii disuse atrophy of various ICU bedridden patients.

Description

Technical Field

[0001] This invention belongs to the field of medical rehabilitation and intensive care technology, and in particular relates to an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients. Background Technology

[0002] Patients in the Intensive Care Unit (ICU) are highly susceptible to acquired myasthenia gravis due to multiple factors, including prolonged bed rest, immobilization, stress response, inflammatory damage, and metabolic disorders. Biceps brachii muscle loss is one of the most common clinical manifestations. As a core muscle group of the upper limb, the reduction in muscle thickness, cross-sectional area, and quality of the biceps brachii directly leads to decreased upper limb muscle strength, impaired limb function, significantly prolonged mechanical ventilation and ICU stay, hindering subsequent weaning and rehabilitation, and severely impacting the prognosis and quality of life of critically ill patients. Therefore, targeted interventions to address biceps brachii muscle loss in ICU patients, slowing the progression of muscle atrophy, and preserving upper limb muscle function are key research and clinical applications in the field of critical care rehabilitation.

[0003] Currently, clinical rehabilitation interventions for muscle loss in ICU patients have formed several routine technical systems, mainly including routine joint mobilization techniques, neuromuscular electrical stimulation (NMES) techniques, supine power cycling training techniques, manual assisted physical therapy techniques, and bedside ultrasound monitoring techniques. Each technique has certain application scenarios and practical value in clinical practice. However, in specific interventions for biceps muscle loss, they all have significant technical defects and application limitations, failing to achieve efficient, precise, and individualized biceps anti-atrophy rehabilitation interventions. The specific current status and defects of the existing technologies are as follows: Routine joint mobilization techniques are currently the most widely used basic rehabilitation method in ICU clinical practice. The core intervention involves rehabilitation therapists or nurses assisting patients in performing passive flexion, extension, and rotation movements of the upper limb joints such as the shoulder, elbow, and wrist. Simultaneously, patients with voluntary mobility are guided to perform active joint movements in bed. The core function is to maintain the patient's joint range of motion and prevent bedridden complications such as joint contractures and soft tissue adhesions. However, this technique is not designed for muscle protection and strength maintenance, and has fundamental limitations. First, routine joint mobilization only focuses on joint function and does not effectively stimulate muscle tissue, failing to activate compensatory muscle metabolism or delay muscle atrophy. Second, the muscles remain in a non-loaded state during training, making it difficult to generate effective muscle contraction tension, thus having a very limited effect on inhibiting biceps muscle loss. Existing clinical studies have fully validated the limitations of this technology. A prospective longitudinal study published in the *European Journal of Pediatrics* in 2024 by De Oliveira et al. showed that even after routine joint rehabilitation care, the incidence of biceps atrophy in ICU children remained as high as 30.8% within two weeks of hospitalization. A study published in the *Journal of Imaging* in 2025 by Arruda et al. further confirmed that during routine joint mobilization interventions in critically ill neurological patients, significant pathological deterioration occurred in biceps thickness, cross-sectional area, and echogenicity, with statistically significant differences between groups (p<0.05), clearly demonstrating that routine joint mobilization cannot effectively prevent biceps muscle loss in ICU patients. Furthermore, this technology lacks a quantified muscle load stimulation mechanism and cannot adjust training intensity based on the patient's real-time muscle strength level, resulting in a severe deficiency in individualized intervention capabilities.

[0004] Neuromuscular electrical stimulation (NMES) is a commonly used clinical intervention for targeted prevention of muscle atrophy in critically ill patients. It involves attaching electrodes to the belly of the biceps brachii muscle and using low-frequency current to induce passive muscle contraction, thereby stimulating muscle metabolism and delaying disuse atrophy. A 2022 randomized controlled trial by Cebeci et al. confirmed that physical therapy combined with NMES can effectively reduce biceps brachii muscle loss in sepsis patients, demonstrating a certain degree of muscle protection. However, this technique also has significant drawbacks: it is a purely passive muscle stimulation method, meaning patients cannot generate voluntary muscle contractions; it only achieves passive muscle activity and cannot rebuild the patient's damaged neuromuscular control ability, making it difficult to fundamentally repair muscle function. Furthermore, this technique is highly dependent on external power sources and specialized electrode consumables; the equipment operation process is complex, requiring full-time monitoring by professional rehabilitation personnel, resulting in high labor and material costs and limited ease of clinical implementation. In addition, this technology has problems such as large differences in muscle group intervention and limited applicable population. Clinical studies have confirmed that its muscle protection effect on the rectus femoris muscle of the lower limb is weak, and the intervention effect is significantly affected by factors such as gender and age. It lacks universality and is difficult to be stably applied to the intervention of the biceps brachii muscle in different types of ICU patients.

[0005] Supine ergometer training is a mainstream technology for bedside aerobic rehabilitation of critically ill patients. It primarily improves limb muscle strength and physical mobility through active or passive lower limb circulation in supine and semi-recumbent positions. Some devices also include simple upper limb training components. A case report published in the *Journal of Nippon Medical School* in 2023 by Saito et al. showed that recumbent ergometer rehabilitation training in critically ill COVID-19 patients effectively improved hand grip strength, MRC muscle strength scores, and basic motor abilities. However, this technology has inherent limitations in its intervention on the biceps brachii: the core training module focuses on lower limb muscles, while the upper limb training components are rudimentary, offering no specific, targeted training stimulation for the biceps brachii and failing to achieve anti-atrophy training. Furthermore, the device is bulky and requires fixed installation next to the ICU bed, occupying scarce medical space and exhibiting poor adaptability. At the level of intelligent intervention, the training mode of this technology is singular and fixed, and it cannot intelligently adjust the training load according to the patient's real-time muscle strength status. Furthermore, it lacks real-time monitoring and feedback functions for core indicators such as biceps muscle thickness and cross-sectional area, resulting in extremely low precision and personalization of intervention.

[0006] Assisted physical therapy (APPT) technology, relying on the professional techniques of rehabilitation therapists, provides ICU patients with personalized rehabilitation services such as passive joint movement, assisted-active training, and resistance training. Its flexible intervention methods have led to its widespread application in critical care rehabilitation. However, this technology faces significant barriers to application: firstly, the training process is highly dependent on manual operation, limited by staff scheduling and working hours, making it impossible to achieve 24-hour continuous rehabilitation intervention, and the frequency and continuity of training cannot be guaranteed; secondly, training intensity, range of motion, and intervention duration depend entirely on the therapist's subjective experience, lacking standardized operating procedures, resulting in significant differences in intervention effects among different operators and insufficient stability. Furthermore, the technology lacks a quantitative assessment system, making it impossible to accurately monitor changes in biceps muscle condition and precisely adjust training programs according to individual patient muscle strength differences, leading to inconsistent intervention effects.

[0007] Bedside ultrasound monitoring is currently a core and reliable method for clinically assessing the muscle status of ICU patients. Ultrasound imaging can accurately detect key indicators such as biceps brachii thickness, muscle cross-sectional area, and echo intensity, providing a direct and objective reflection of the progression of muscle atrophy. Multiple studies have validated it as a highly reliable tool for muscle status assessment. However, this technology only provides monitoring and assessment functions and lacks any therapeutic intervention attributes. It cannot directly target the biceps brachii or halt the process of muscle loss. Furthermore, this technology requires operation by a professional ultrasound physician; primary care and rehabilitation staff cannot perform the tests independently, making it difficult to achieve continuous dynamic monitoring of the biceps brachii muscle status and capture subtle changes in muscle atrophy in real time. Simultaneously, in the current clinical system, ultrasound monitoring data is disconnected from rehabilitation training programs, failing to form a closed-loop control mechanism of "monitoring-analysis-intervention." Monitoring data cannot directly guide adjustments to rehabilitation training, thus failing to fully realize the value of monitoring.

[0008] Based on the current application status and shortcomings of existing technologies, it is evident that current clinical intervention systems for biceps muscle loss in ICU patients face several common technical bottlenecks, severely hindering the rehabilitation effects of upper limb muscles in critically ill patients: First, existing technologies lack specialized physical training devices for the biceps brachii in ICU patients, and there is no professional intervention equipment focusing on anti-atrophy of the upper limb biceps brachii; Second, current mainstream intervention methods primarily rely on passive electrical stimulation and lower limb mechanical training, failing to achieve active and controllable biceps brachii training and hindering the activation of patients' autonomic neuromuscular regulation functions; Third, muscle status monitoring and rehabilitation training are separated, lacking a real-time data feedback mechanism, thus preventing dynamic and precise intervention; Fourth, the lack of an intelligent control system prevents the automatic switching between passive, assisted, and active training modes based on individual patient muscle strength levels and the degree of muscle atrophy, and also fails to accurately match appropriate training loads, resulting in a severe deficiency in individualized intervention capabilities. Therefore, developing a targeted intervention device for biceps brachii muscle loss in ICU patients that enables active training and possesses real-time monitoring and intelligent control functions is a pressing technical problem that needs to be solved in the field of critical care rehabilitation. Summary of the Invention

[0009] The purpose of this invention is to provide an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients. This device is designed to assist patients who are completely comatose or lack muscle strength. In fully assisted mode, the device actively assists patients in performing flexion and extension exercises of the upper limbs. For conscious patients with some muscle strength, the device can operate in semi-assisted mode, providing resistance exercises based on the patient's upper limb strength. These two operating modes enable biceps brachii muscle training for different types of patients.

[0010] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution.

[0011] The present invention is an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, comprising a motion interaction device and a pneumatic control system. The motion interaction device is adapted to the patient's upper limb, enabling power transmission and stroke limitation for the patient's upper limb flexion and extension movements. It can adapt to the upper limb size of patients of different body types and can selectively connect to pneumatic drive force. The pneumatic control system is connected to the air circuit of the motion interaction device and can output adjustable positive pressure, negative pressure and normal pressure air pressure signals to achieve precise control and stable output of air pressure waveform; The auxiliary exercise device is equipped with a full-assisted mode and a semi-assisted mode. In the full-assisted mode, the motion interaction device is driven by the pneumatic control system to actively help patients with no muscle strength or who are in a coma to complete upper limb flexion and extension exercises. In the semi-assisted mode, the corresponding resistance force is output according to the upper limb muscle strength of the patient to provide resistance exercise for conscious patients with a certain amount of muscle strength, which is suitable for the biceps rehabilitation exercise needs of ICU patients with different muscle strength states.

[0012] Furthermore, the motion interaction device includes an upper limb adaptation and fixing component, a rotation transmission component, a pneumatic drive component, and a docking adjustment component; The upper limb adaptation and fixation assembly includes a telescopic rear arm support plate and a forearm support plate with a sliding structure. The rear arm support plate is fixedly connected to the device housing through a support structure. The rear arm support plate and the forearm support plate are hinged through a revolute joint. A forearm slider is slidably mounted on the forearm support plate. The rear arm support plate can extend and retract to adapt to different rear arm lengths. The forearm slider can slide relative to the forearm support plate to adapt to different forearm lengths. Fabric straps are provided at both ends of the forearm slider and the rear arm support plate. The rotational transmission assembly includes a spool, two sets of flexible belts, two cylindrical pulleys distributed vertically, a traction cylindrical rod, and a traction groove. The spool is rotatably connected to the support structure. The forearm support plate is fixedly connected to both ends of the spool to achieve synchronous rotation of the two. Two sets of flexible belts are fixed on the spool. The two sets of flexible belts are respectively connected to the two traction cylindrical rods via the cylindrical pulleys. The traction cylindrical rods are slidably assembled in the horizontal traction groove of the device housing. The pneumatic drive assembly includes two sets of pneumatic artificial muscle groups arranged vertically, a rigid thin plate, and a guide cylindrical rod. The fixed ends of the two sets of pneumatic artificial muscle groups are fixedly connected to the device housing, and the moving ends are connected to the guide cylindrical rod through the rigid thin plate. The guide cylindrical rod is slidably assembled in the guide groove of the device housing. The docking adjustment assembly includes multiple sets of rotatable hooks, which are rotatably mounted on both ends of the guide cylindrical rod and can be manually engaged and disengaged from the traction cylindrical rod.

[0013] Furthermore, each group of pneumatic artificial muscles contains 120 pneumatic artificial muscles, which are arranged in 6 layers and 12 columns. The moving ends of all pneumatic artificial muscles in the same group are fixed to a rigid thin plate to achieve synchronous deformation. The pneumatic artificial muscle adopts a transversely supported corrugated densely packed multi-cavity soft pneumatic drive structure. Under normal pressure, it can passively extend under external force to provide motion resistance; under positive pressure, it can expand and actively extend to provide thrust; and under negative pressure, it can actively contract to provide tension.

[0014] Furthermore, the pneumatic artificial muscle group adopts a symmetrical partitioned drive structure, with the i-th column and the 13-i-th column of pneumatic artificial muscles as an independent drive unit, where i is an integer from 1 to 6. The same drive unit applies a pneumatic drive signal synchronously, so as to realize the graded and flexible adjustment of the output force of the pneumatic artificial muscle group while ensuring the symmetry of the output force.

[0015] Furthermore, both the guide groove and the traction groove are arranged parallel to the bottom surface of the device housing. The guide groove is used to limit the direction of extension and contraction of the pneumatic artificial muscle group, ensuring the consistency of deformation and the concentration of force of all pneumatic artificial muscles. The length of the traction groove is less than the length of the guide groove, limiting the maximum effective extension stroke of the pneumatic artificial muscle, and making the direction of movement of the flexible belt coaxial with the direction of extension and contraction of the pneumatic artificial muscle.

[0016] Furthermore, the lengths of the two sets of flexible bands are matched to the upper limb flexion-extension limit settings; In the initial extended state, the upper flexible band adapts to the initial undeformed state of the artificial muscle group, while the lower flexible band keeps the corresponding artificial muscle group in a fully extended state. In the maximum flexed state of the upper limb, the roller winds around the upper flexible band to keep the corresponding artificial muscle group fully extended, and the roller releases the lower flexible band to keep the corresponding artificial muscle group back to its initial undeformed state. Through the synchronous rotation of the forearm support plate and the roller, the linkage and matching of the upper limb flexion and extension movement and the pneumatic artificial muscle extension and contraction deformation are achieved.

[0017] Furthermore, the pneumatic control system includes an electrical signal control module and a dual-path symmetrical pneumatic transmission module. The electrical signal control module includes a host computer, a microcontroller, a switching power supply, and an NMOS module. The dual-path symmetrical pneumatic transmission module includes a pump that can be used for both pumping and discharging, a two-position two-way solenoid valve, an air buffer bottle, a pressure sensor, an air on / off valve group, and an air pipe. The switching power supply converts household electricity into 24V DC power to power the microcontroller and NMOS module; the host computer imports the preset target air pressure waveform program into the microcontroller, and the microcontroller outputs a PWM wave to drive the pump and the two-position two-way solenoid valve through the NMOS module; the air pressure sensor collects the air pressure signal in the air path in real time and feeds it back to the microcontroller, and the microcontroller achieves accurate tracking of the target air pressure waveform by the air path air pressure through PID feedback control.

[0018] Furthermore, the dual-path symmetrical pneumatic transmission module independently corresponds to two sets of pneumatic artificial muscle groups, wherein any single-path air path structure in the dual-path symmetrical pneumatic transmission module is as follows: The air inlet and outlet of the pump are connected to two sets of two-position two-way solenoid valves via a three-way connector. The two two-position two-way solenoid valves on the air pump inlet side are connected to the main air port of the air circuit on / off valve group, and the other is connected to the outside atmosphere. The two two-position two-way solenoid valves on the air pump outlet side are connected to the main air port of the air circuit on / off valve group, and to the outside atmosphere. The gas buffer bottle and the pressure sensor are connected in series in the gas path between the two-position two-way solenoid valve and the gas path on / off valve group via a three-way connector.

[0019] Furthermore, the air circuit on / off valve group consists of 12 manually operated valves arranged in 2 rows and 6 columns. The 6 columns of valves correspond to the 6 independent drive units of the pneumatic artificial muscle group. Each manually operated valve controls the air circuit on / off of 12 pneumatic artificial muscles and can independently adjust the working status of each drive unit.

[0020] Furthermore, the pneumatic control system can achieve continuous positive and negative adjustment of air pressure, and suppress air pressure fluctuations caused by the operation of air pump and solenoid valve through air circuit buffer bottle, thereby improving air pressure control accuracy. By controlling the on / off state of the air circuit valve group and adjusting the positive and negative air pressure, the tensile stiffness of the device can be adjusted over a wide range. The maximum tensile stiffness is the total stiffness when both sets of pneumatic artificial muscle groups are fully contracted under negative pressure, and the minimum tensile stiffness is the negative stiffness when both sets of pneumatic artificial muscle groups are fully extended under positive pressure, which can be adapted to the resistance training and passive assisted training needs of patients with different muscle strengths.

[0021] The present invention has the following beneficial effects.

[0022] First, this device enables integrated dual-mode training, fully covering and adapting to the muscle strength status of different critically ill patients, thus overcoming the technical shortcomings of existing technologies, such as poor adaptability and insufficient targeting.

[0023] Existing intervention methods such as conventional joint mobilization, NMES electrical stimulation, and supine power cycling are fixed and singular, only achieving passive stimulation or a single form of training. They cannot address the rehabilitation needs of different types of ICU patients, such as those who are comatose with no muscle strength or those who are conscious with low muscle strength, and they lack the ability to adapt and adjust muscle strength, resulting in poor individualized intervention effects. This invention innovatively sets up a dual training mode of fully assisted and semi-assisted training, which can be adapted to all ICU patients: For patients who are completely comatose and have no voluntary muscle strength, the fully assisted mode can be switched to, and the motion interaction device driven by the pneumatic control system actively drives the patient's upper limb to complete standard flexion and extension movements, achieving passive and regular biceps brachii training, which makes up for the shortcomings of conventional rehabilitation methods in terms of insufficient muscle stimulation and poor atrophy prevention and control; For conscious patients with some upper limb muscle strength, the semi-assisted resistance training mode can be switched to, which adaptively outputs matched resistance force according to the patient's voluntary exertion, achieving active resistance training and effectively activating neuromuscular regulation function. Meanwhile, this device can flexibly change the rigidity and driving force of the equipment by precisely adjusting the operating parameters of the pneumatic artificial muscle. It can dynamically adjust the training intensity according to the patient's different disease stages, different degrees of muscle atrophy, and different muscle strength levels. Compared with the existing fixed parameters and single mode intervention technology, it completely solves the problem that traditional technology cannot be individualized to adapt to the patient's muscle state, maximizes the biceps training effect of different patients, and accurately slows down the process of muscle loss.

[0024] Secondly, the present invention adopts a soft pneumatic artificial muscle driving structure, which greatly improves the safety and adaptability of bedside rehabilitation training and avoids the risk of hard damage from traditional equipment.

[0025] Existing mechanical devices such as supine power bicycles mostly have rigid drive structures, resulting in high rigidity and poor cushioning. ICU patients are physically weak and have low joint tolerance, making them highly susceptible to joint traction injuries and secondary muscle injuries. Manual assisted training relies on human manipulation, leading to unstable force control and high safety risks. NMES electrical stimulation can easily cause discomfort from electrical stimulation, limiting its applicability. This invention utilizes a soft pneumatic artificial muscle as the core drive unit, possessing excellent flexibility and passive deformation characteristics. The drive process is free of rigid impact and can adaptively fine-tune according to the patient's upper limb movement trajectory, conforming to the physiological movement patterns of human upper limb flexion and extension. Throughout the training process, it provides stable training drive force and resistance while effectively cushioning the impact of movement, avoiding limb injuries caused by rigid equipment's rigid traction and overtraining. It is suitable for the special clinical scenario of ICU critically ill patients with weak physical condition, low tolerance, and multiple complications. Compared with various existing intervention technologies, its clinical safety and comfort are significantly improved, meeting the stringent application requirements of bedside rehabilitation for critically ill patients.

[0026] Third, this invention enables precise and controllable air pressure waveforms and flexible switching of air paths, achieving refined and wide-ranging individualized rehabilitation training, and solving the problems of low training precision, lack of closed-loop control, and poor training effect of traditional techniques.

[0027] Existing clinical intervention techniques generally suffer from drawbacks such as unquantifiable training parameters and low control precision. Routine joint movements and assisted training rely on subjective experience and lack standardized quantitative control systems. Traditional equipment cannot achieve precise load adjustment, and monitoring and training are disconnected, making accurate intervention difficult. This invention utilizes a pneumatic control system to allow for free selection of manual airflow on / off, while simultaneously providing precise output and control of various air pressure waveforms. It can customize training rhythm, load intensity, and exercise frequency based on the patient's biceps muscle recovery status. This design significantly expands the clinical applicability of the equipment, meeting the refined training needs of various critically ill patients, from those with severe muscle atrophy and no voluntary muscle strength to those with mild muscle weakness requiring resistance strengthening. Through controllable, regular, and appropriate muscle load stimulation, it effectively activates biceps muscle metabolism, maintains muscle volume and strength, and solves the core pain points of traditional techniques such as ineffective muscle stimulation, inconsistent training results, and inability to precisely intervene in muscle loss. It constructs a highly efficient intervention system of "individualized parameters - precise drive - appropriate training," effectively improving the prevention and control of biceps disuse atrophy and the quality of rehabilitation in ICU patients. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0029] Figure 1 A perspective view of an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, provided as an embodiment of this application.

[0030] Figure 2 This is a cross-sectional perspective view of an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, provided as an embodiment of this application.

[0031] Figure 3 This is a front view of an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, provided as an embodiment of this application.

[0032] Figure 4 A side view of an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, provided in an embodiment of this application.

[0033] Figure 5 This is a top view of an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, provided as an embodiment of this application.

[0034] Figure 6 This is a schematic diagram of the structure of a pneumatic artificial muscle.

[0035] Figure 7 This is a cross-sectional view of a pneumatic artificial muscle.

[0036] Figure 8 This is a 3D view of the gas circuit on / off valve assembly.

[0037] Figure 9 This is the front view of the gas circuit on / off valve assembly.

[0038] Figure 10 This is a rear view of the gas circuit on / off valve assembly.

[0039] Figure 11 The diagram shows the air path structure (solid line) and circuit structure (dashed line) of the pneumatic control system.

[0040] Figure 12 This is a schematic diagram of the air pressure waveform tracking result output by the pneumatic control system.

[0041] In the attached diagram: 1-device housing, 2-support structure, 3-forearm support plate, 4-rear arm support plate, 5-fabric strap, 6-roller, 7-flexible belt, 8-cylindrical pulley, 9-traction cylindrical rod, 10-traction groove, 11-pneumatic artificial muscle assembly, 12-rigid thin plate, 13-guide cylindrical rod, 14-hook, 15-guide groove, 16-manual switch, 17-connecting air tube, 18-air supply side connector, 110-diaphragm, 111-airbag, 112-airway. Detailed Implementation

[0042] The technical solutions of the present invention will be described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments.

[0043] Please see Figure 1-11 This application discloses an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients. It is specifically designed for the disuse atrophy and muscle loss of biceps brachii in long-term bedridden ICU patients. It is suitable for the bedside rehabilitation needs of two types of critically ill patients: those who are comatose and have no muscle strength, and those who are awake and have low muscle strength. The device consists of two core parts: a motion interaction device and a pneumatic control system. It can achieve adaptive switching between two modes: fully assisted passive exercise and semi-assisted resistance exercise. It effectively makes up for the technical defects of existing critical care biceps brachii rehabilitation equipment, such as poor targeting, insufficient intelligence, and low safety.

[0044] Specifically: The motion interaction device is the core of the device's human-machine adaptation and power transmission. It is responsible for fitting the patient's upper limb, transmitting pneumatic driving force / resistance force, and limiting the range of motion, so as to realize standardized and controllable training of upper limb flexion and extension movements. The whole assembly is mounted on the device shell 1 and mainly includes four modules: upper limb adaptation and fixing components, rotation transmission components, pneumatic drive components, and docking and adjustment components. The positions of each module are precisely laid out and the transmission linkage is close.

[0045] Among them, such as Figures 1 to 5 As shown, the upper limb adaptation and fixation component is a support and positioning structure for the patient's upper limb, including a telescopic posterior arm support plate 4 and a forearm support plate 3 with a sliding structure. The forearm support plate 3 and the posterior arm support plate 4 are connected by a rotating joint, so that the forearm support plate 3 can rotate around the hinge point from 0° to the maximum bending angle of the upper limb, accurately simulating the physiological movement trajectory of the human elbow joint flexion and extension.

[0046] The posterior arm support plate 4 is fixedly mounted on the internal support structure 2 of the device housing 1, maintaining a static fixed state. The posterior arm support plate 4 adopts a telescopic structure, which can adaptively extend and retract according to the length of the patient's posterior arm, adapting to the upper limb size of patients of different heights and body types. As a telescopic implementation method, the posterior arm support plate 4 includes a fixed support plate and a movable support plate. The fixed support plate has a set of insertion holes along its length direction. The movable support plate has two insertion rods integrally formed on its side that are adapted to the insertion holes of the fixed support plate, so that the movable support plate and the fixed support plate can be movably inserted to achieve extension and retraction. Of course, the fixed support plate has locking bolts perpendicular to the insertion holes on its side. The movable support plate can be locked and released by rotating the locking bolts inward and outward.

[0047] Of course, in order to fix the patient's upper limb and hind arm, the two ends of the hind arm support plate 4 (i.e., the fixed support plate and the movable support plate) are fixed with sewn fabric straps 5. The patient's hind arm can be stably bound to the support plate surface by wrapping the straps, locking with buckles or fastening with Velcro, so as to avoid upper limb displacement or slippage during training and ensure training stability.

[0048] The forearm support plate 3 has horizontal sliding grooves on both sides, and a forearm slider is slidably assembled inside the groove. The forearm slider can slide freely along the length of the forearm support plate 3 to accommodate the differences in forearm length among different patients. A flexible fabric strap 5 is fixedly installed on the surface of the forearm slider to tightly bind the patient's forearm to the surface of the slider, so that the forearm, the forearm slider and the forearm support plate 3 form a synchronous movement as a whole, preventing the forearm from sliding and misaligning relative to the support plate during training, and ensuring the accuracy of flexion and extension training.

[0049] Continue as Figures 1 to 5 As shown, the rotary transmission assembly is the core of power transmission, responsible for converting the telescopic power of the pneumatic drive assembly into the rotational bending and extending power of the forearm support plate 3. It includes a roller 6, two sets of flexible belts 7, two cylindrical pulleys 8 arranged in parallel, two traction cylindrical rods 9, and a horizontal traction groove 10.

[0050] The scroll 6 is positioned directly below the rear arm support plate 4 in the center. Both ends of the scroll 6 are rotatably connected to the internal support structure 2 of the device through a rotating joint, allowing it to rotate freely in the circumferential direction. At the same time, both ends of the scroll 6 are rigidly fixed to the bottom support arm of the forearm support plate 3, so that the scroll 6 and the forearm support plate 3 form a synchronous rotation structure. The flexion and extension rotation of the forearm support plate 3 can directly drive the scroll 6 to rotate synchronously in both directions, and the rotational motion of the scroll 6 can also drive the forearm support plate 3 to complete the flexion and extension action in the opposite direction.

[0051] Two sets of flexible belts 7 are symmetrically fixedly connected to one end of the cylindrical surface of the spool 6. The two sets of flexible belts 7 are arranged one-to-one. The other end of each belt passes over two cylindrical pulleys 8 to complete the turning. The two cylindrical pulleys 8 are fixedly installed inside the device housing 1 and can rotate freely, effectively reducing friction loss during the transmission of the flexible belts 7. After turning, the flexible belts 7 extend horizontally and are fixedly connected to the middle of the upper and lower smooth traction cylindrical rods 9. The two traction cylindrical rods 9 are arranged horizontally in parallel, and their two ends are slidably fitted into the horizontal traction grooves 10 symmetrically opened on both sides of the device housing 1. The traction grooves 10 are arranged parallel to the bottom surface of the device housing 1, strictly limiting the traction cylindrical rods 9 to sliding back and forth only in the horizontal direction, preventing vertical offset, tilting and jamming. Both ends of the traction cylindrical rods 9 extend out of the outside of the device housing 1, and annular grooves are opened on the extended rods for subsequent stable docking with the hook 14 structure.

[0052] In this embodiment, the lengths of the two sets of flexible bands 7 are precisely matched to perfectly adapt to the patient's upper limb flexion and extension limit: in the initial fully extended state of the upper limb, the upper flexible band 7 remains relaxed to adapt to the initial undeformed state of the pneumatic artificial muscle group 11, while the lower flexible band 7 is fully taut, corresponding to the lower pneumatic artificial muscle group 11 being in a fully extended state; when the forearm support plate 3 drives the upper limb to bend to the maximum angle, the roller 6 rotates in the forward direction to wind the upper flexible band 7, pulling the upper pneumatic artificial muscle group 11 to complete the full extension, while the roller 6 releases the lower flexible band 7 in the reverse direction, and the lower pneumatic artificial muscle group 11 returns to its initial undeformed state, realizing the precise linkage and matching between the upper limb flexion and extension movement and the pneumatic artificial muscle extension and contraction deformation.

[0053] like Figures 1 to 7 As shown, the pneumatic drive assembly is the power source of the device, providing controllable driving force and resistance force for upper limb flexion and extension training. It includes two sets of pneumatic artificial muscle groups 11 that are aligned vertically and arranged in parallel, two rigid thin plates 12, and two smooth guide cylindrical rods 13. The two sets of pneumatic artificial muscle groups 11 have completely identical structures and parameters and are symmetrically distributed in the upper and lower regions inside the device housing 1.

[0054] Each pneumatic artificial muscle group 11 comprises 120 pneumatic artificial muscles, arranged in a neat, densely packed pattern of 6 layers and 12 columns, ensuring uniform distribution and symmetrical force distribution. Each pneumatic artificial muscle utilizes a corrugated, densely packed, multi-cavity soft pneumatic drive structure supported by a diaphragm 110. Airbags 111 are positioned between adjacent diaphragms 110, and these airbags are connected via airways 112. Inflation and inhalation allow for the extension and contraction of the pneumatic artificial muscles, providing triple working characteristics: passive extension under normal pressure, active extension under positive pressure, and active contraction under negative pressure. This results in excellent flexibility, no rigid impact, and suitability for the limb tolerance of severely weakened patients. The fixed end of each pneumatic artificial muscle group 11 is rigidly fixed to the inner wall of the device housing 1. A rectangular through-hole is provided at the corresponding fixed position on the housing, allowing for the connection of an air tube, thus connecting the pneumatic artificial muscle group 11 to the external pneumatic control system.

[0055] Each pneumatic artificial muscle group 11 has a rigid thin plate 12 fixedly connected to its moving end. The two rigid thin plates 12 are parallel to each other and vertically aligned. A rigid, smooth guide cylindrical rod 13 is rigidly connected to the center of the outer side of each rigid thin plate 12. The two guide cylindrical rods 13 are arranged in parallel and their ends are slidably fitted into the guide grooves 15 on both sides of the device housing 1. The guide grooves 15 are also arranged parallel to the bottom surface of the housing, and the overall length of the guide grooves 15 is greater than the length of the traction groove 10. The guide grooves 15 can strictly limit the direction of extension and contraction of the pneumatic artificial muscle group 11, ensuring that all artificial muscles only extend and contract synchronously in the horizontal direction, eliminating deformation deviation and uneven force, and achieving concentrated force output. The length limit of the traction groove 10 determines the maximum effective extension stroke of the pneumatic artificial muscle, accurately matching the upper limb flexion and extension movement limit, and avoiding overstretching that could cause injury to the patient's limb.

[0056] Meanwhile, the pneumatic artificial muscle group 11 adopts a symmetrical partitioned drive structure, with the i-th column and the 13-i-th column of pneumatic artificial muscles as an independent drive unit (i is 1, 2, 3, 4, 5, 6), for a total of 6 independent drive units. The 12 pneumatic artificial muscles in the same drive unit receive the pneumatic drive signal and deform synchronously. Under the premise of ensuring the overall output force is symmetrical and stable, the output force can be graded and finely and flexibly adjusted to meet the rehabilitation training needs of different intensities.

[0057] The docking adjustment assembly is a mode switching and power on / off adjustment structure, including four sets of rotatable hooks 14. A hook 14 is rotatably mounted on the outer sides of each of the left and right ends of the two guide cylindrical rods 13. The hooks 14 can rotate freely around the ends of the guide cylindrical rods 13. The hooks 14 are bidirectional hooks, with one end hinged to the guide cylindrical rod 13 and the other end having an open hook groove. They can be manually operated to quickly engage or disengage with the groove at the end of the traction cylindrical rod 9.

[0058] When hook 14 is interlocked with traction cylindrical rod 9, the extension and contraction force of pneumatic artificial muscle group 11 can be completely transmitted to the reel 6 through guide cylindrical rod 13, hook 14, traction cylindrical rod 9, and flexible belt 7, thereby driving the forearm support plate 3 to complete flexion and extension movements. When hook 14 is manually disengaged, the power transmission link of the corresponding pneumatic artificial muscle group 11 is disconnected, and the artificial muscle group stops working. By independently controlling the on / off state of the upper and lower hooks 14, the single-group and double-group artificial muscle collaborative working modes can be flexibly switched, and the overall driving stiffness and resistance force of the device can be precisely adjusted.

[0059] like Figures 8 to 11 As shown, the pneumatic control system is the core of the device's intelligent regulation and control. It is responsible for outputting continuously adjustable positive, negative, and normal pressure air pressure signals to precisely control the extension and contraction state of the pneumatic artificial muscles, realize training mode switching and load adaptive adjustment. The whole system is divided into an electrical signal control module and a dual-path symmetrical pneumatic transmission module, which can form a closed-loop control system of "signal input - air pressure regulation - real-time feedback - error correction".

[0060] Specifically, the electrical signal control module is responsible for program input, signal output, and closed-loop control. It includes a host computer, a microcontroller, a switching power supply, and an NMOS module, all connected in an orderly manner via circuitry. The switching power supply connects to standard 220V AC power and can convert it to output a stable 24V DC power, continuously powering the microcontroller and NMOS module to ensure stable operation of the electrical control system. The host computer serves as the program editing and command input terminal, allowing for the editing and preset of target air pressure waveform programs for different rehabilitation scenarios, and the downloading and importing of these programs into the microcontroller's internal storage.

[0061] The microcontroller serves as the core control unit. After receiving the target air pressure waveform command from the host computer, it precisely outputs a PWM control pulse signal. This signal is amplified by an NMOS module and synchronously drives the dual-purpose pump and the two-position two-way solenoid valve to start, stop, and switch operating states in unison. Simultaneously, the microcontroller receives real-time air pressure feedback signals from the air pressure sensor. Using a built-in PID control algorithm, it compares the target air pressure with the actual air pressure and corrects the control parameters in real time. This achieves high-precision tracking of the target air pressure waveform by the actual air pressure, ensuring the stability and accuracy of the training load. Figure 12 The diagram shows the air pressure waveform tracking results output by the pneumatic control system. The diagram illustrates the tracking structure of different waveform shapes, such as triangular waves and sine waves. The black curve in the diagram represents the target air pressure output, and the red curve represents the actual air pressure. The tracking structure reflects the stability and accuracy of the training load.

[0062] The dual-path symmetrical pneumatic transmission module is equipped with two identical and independently operating pneumatic circuits, which respectively control the two pneumatic artificial muscle groups 11. Each pneumatic circuit includes a pump that can be used for both pumping and striking, two two-position two-way solenoid valves, a pneumatic buffer bottle, a pressure sensor, a pneumatic on / off valve group, and a connecting air pipe 17. All components are connected in a sealed manner through a three-way connector and a sealed air pipe, eliminating the risk of air leakage or pressure drop.

[0063] The assembly and connection relationship of the single-circuit air circuit is as follows: the air inlet and outlet of the pump are respectively connected to two sets of two-position two-way solenoid valves through three-way connectors; one valve port of the two two-position two-way solenoid valves on the air inlet side is connected to the main air port of the air circuit on / off valve group, and the other valve port is directly connected to the outside atmosphere; one valve port of the two two-position two-way solenoid valves on the air outlet side is connected to the main air port of the air circuit on / off valve group, and the other valve port is connected to the outside atmosphere. The air circuit on / off valve group consists of 12 manual switches 16 valves, arranged in 2 rows and 6 columns. The 6 columns of switches correspond to the 6 independent drive units of the pneumatic artificial muscle group 11. Each manual switch 16 valve independently controls the air circuit on / off of the connecting air pipe 17 connected to the 12 pneumatic artificial muscles. The working state of any drive unit can be adjusted independently to achieve fine-grained zone control. The opposite side of the connecting air pipe 17 is provided with an air supply connector 18 that connects to the air supply side of the pneumatic control system.

[0064] In the airflow path, on the air pipe section between the 2-position 2-way solenoid valve and the air flow on / off valve assembly, an air flow buffer bottle and a pressure sensor are connected in series via a tee connector. The air flow buffer bottle is located closer to the solenoid valve, and the pressure sensor is located closer to the air flow on / off valve assembly. The air flow buffer bottle effectively buffers air pressure fluctuations caused by the start / stop of the air pump and the switching of the solenoid valve, eliminates air pressure pulse interference, and significantly improves the stability of air pressure output. The pressure sensor collects the internal air pressure value of the air flow in real time and synchronously feeds it back to the microcontroller, providing data support for PID closed-loop control.

[0065] Based on the above, this application provides an auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients. It can provide both fully assisted and semi-assisted exercise for the upper limbs of ICU patients, depending on their individual circumstances. The specific operation process is as follows: 1): Operation procedure of the auxiliary exercise device in semi-assisted mode The semi-assisted mode is designed for conscious patients with some muscle strength. The patient can actively flex and extend their upper limb, and the assistive exercise device sets an appropriate resistance level based on the patient's muscle strength. This resistance training helps prevent biceps muscle loss. In this mode, the pneumatic artificial muscle assembly 11 is connected to the upper traction cylindrical rod 9 via hooks 14 on both sides, thus connecting the pneumatic artificial muscle assembly 11 to the upper flexible band 7. When the patient's forearm moves in flexion and extension, the roller 6, fixedly connected to the forearm, rolls up or releases the flexible band 7, causing the pneumatic artificial muscle assembly 11 to extend and deform. Through the stiffness adjustment of the pneumatic artificial muscle assembly 11 and the selective connection of the hooks 14, different resistance levels can be achieved for the patient's upper limb flexion and extension.

[0066] The specific operating procedure is as follows: (1) Place the patient’s upper limb on the hind arm support plate 4 and the forearm support plate 3 of the motion interaction device. Place the hind arm on the hind arm support plate 4 and the forearm on the forearm support plate 3. Then adjust the slider on the forearm support plate 3 and the telescopic structure of the hind arm support plate 4. Once it is appropriate, use the fabric strap 5 to bind the upper limb.

[0067] (2) Connect the hooks 14 at both ends of the guide cylindrical rod 13 of one or two pneumatic artificial muscle groups 11 to the corresponding ends of the upper traction cylindrical rod 9. Adjust the air circuit on / off valve group to select some or all artificial muscles to be connected to the air circuit. Among them, the unconnected artificial muscles are in a closed state and are in a negative air pressure state during elongation and deformation. The connected artificial muscles are controlled by the pneumatic system.

[0068] (3) For the connected artificial muscle, the air pressure waveform and parameters are set through the host computer, including zero air pressure (directly connected to the external atmospheric pressure), negative air pressure (directly closed the artificial muscle air path), sine wave, triangle wave and user-defined waveform, and then the control program is downloaded to the microcontroller to start the exercise device and begin the exercise.

[0069] (4) Before each use, the patient can obtain a close impedance state by adjusting the gas circuit on / off valve group, determine the state of the on / off valve in the gas circuit on / off valve group, and then achieve a better impedance state through the program.

[0070] 2): Operation procedure of the assistive exercise device in full-assisted mode The fully assisted mode is designed for patients who are completely comatose or lack muscle strength, unable to flex or extend their upper limbs independently. The assistive exercise device then guides the patient's upper limbs to perform flexion movements. In this mode, the pneumatic artificial muscle assembly 11 is connected to the lower traction cylindrical rod 9 via hooks 14 on both sides, thereby connecting the pneumatic artificial muscle assembly 11 to the lower flexible band 7. When the artificial muscle assembly reciprocates in extension and contraction, it drives the roller 6 to rotate reciprocally via the flexible band 7, thereby driving the forearm support plate 3 to flex and extend, ultimately driving the patient's upper limbs to perform flexion and extension movements. Through the stiffness adjustment of the pneumatic artificial muscle assembly 11 and the selective connection of the hooks 14, different driving effects can be achieved for the patient's upper limb flexion and extension, including adjustment of the flexion and extension frequency and amplitude.

[0071] The specific operating procedure is as follows: (1) Place the patient’s upper limb on the hind and forearm support plates 3 of the motion interaction device, with the hind arm on the hind arm support plate 4 and the forearm on the forearm support plate 3. Then adjust the slider on the forearm support plate 3 and the telescopic structure of the hind arm support plate 4. Once it is appropriate, use the fabric straps 5 to bind the upper limb.

[0072] (2) Connect the upper pneumatic artificial muscle assembly 11 to both ends of the upper traction cylindrical rod 9, and connect the lower pneumatic artificial muscle assembly 11 to both ends of the lower traction cylindrical rod 9. Adjust the air circuit on / off valve assembly, so that the upper and lower pneumatic artificial muscle assemblies 11 are partially or completely connected to the air circuit, and the two pneumatic artificial muscle assemblies 11 perform antagonistic movements. The artificial muscles that are not connected are in a closed state and are in a negative air pressure state during elongation and deformation. The connected artificial muscles are controlled by the pneumatic system.

[0073] (3) For the connected artificial muscle, the air pressure waveform and parameters are set through the host computer, including zero air pressure (directly connected to the external atmospheric pressure), negative air pressure (directly closed the artificial muscle air path), sine wave, triangle wave and user-defined waveform, and then the control program is downloaded to the microcontroller to start the exercise device and begin the exercise.

[0074] (4) When the patient is using it, he can initially obtain a suitable motion state by adjusting the air circuit on / off valve group, determine the state of the on / off valve in the air circuit on / off valve group, and then achieve a better motion state through the program.

[0075] In summary, this invention, through its modular and integrated structural design, combined with soft pneumatic drive and intelligent closed-loop air pressure regulation technology, solves the technical problems of existing ICU biceps brachii rehabilitation equipment, such as weak targeting, poor safety, insufficient intelligence, and low individualized adaptability. The dual-mode training can fully cover the rehabilitation needs of different critically ill patients. The soft drive has no risk of rigid injury, the air pressure is precisely controllable, and the stiffness adjustment range is wide. It can stably achieve efficient anti-atrophy intervention of the biceps brachii in ICU patients. The clinical adaptability and rehabilitation effect are significantly better than existing conventional technologies.

[0076] The above-described embodiments are merely preferred embodiments of the present invention and not limitations. Those skilled in the art should understand that the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention without departing from the technical solution and inventive concept of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An auxiliary exercise device for preventing biceps brachii muscle loss in ICU patients, characterized in that: Including motion interaction devices and pneumatic control systems; The motion interaction device is adapted to the patient's upper limb, enabling power transmission and stroke limitation for the patient's upper limb flexion and extension movements. It can adapt to the upper limb size of patients of different body types and can selectively connect to pneumatic drive force. The pneumatic control system is connected to the air circuit of the motion interaction device and can output adjustable positive pressure, negative pressure and normal pressure air pressure signals to achieve precise control and stable output of air pressure waveform; The auxiliary exercise device is equipped with a full-assisted mode and a semi-assisted mode. In the full-assisted mode, the motion interaction device is driven by the pneumatic control system to actively help patients with no muscle strength or who are in a coma to complete upper limb flexion and extension exercises. In the semi-assisted mode, the corresponding resistance force is output according to the upper limb muscle strength of the patient to provide resistance exercise for conscious patients with a certain amount of muscle strength, which is suitable for the biceps rehabilitation exercise needs of ICU patients with different muscle strength states.

2. The auxiliary exercise device according to claim 1, characterized in that, The motion interaction device includes an upper limb fitting and fixing component, a rotation transmission component, a pneumatic drive component, and a docking adjustment component. The upper limb adaptation and fixation assembly includes a telescopic rear arm support plate and a forearm support plate with a sliding structure. The rear arm support plate is fixedly connected to the device housing through a support structure. The rear arm support plate and the forearm support plate are hinged through a revolute joint. A forearm slider is slidably mounted on the forearm support plate. The rear arm support plate can extend and retract to adapt to different rear arm lengths. The forearm slider can slide relative to the forearm support plate to adapt to different forearm lengths. Fabric straps are provided at both ends of the forearm slider and the rear arm support plate. The rotational transmission assembly includes a spool, two sets of flexible belts, two cylindrical pulleys distributed vertically, a traction cylindrical rod, and a traction groove. The spool is rotatably connected to the support structure. The forearm support plate is fixedly connected to both ends of the spool to achieve synchronous rotation of the two. Two sets of flexible belts are fixed on the spool. The two sets of flexible belts are respectively connected to the two traction cylindrical rods via the cylindrical pulleys. The traction cylindrical rods are slidably assembled in the horizontal traction groove of the device housing. The pneumatic drive assembly includes two sets of pneumatic artificial muscle groups arranged vertically, a rigid thin plate, and a guide cylindrical rod. The fixed ends of the two sets of pneumatic artificial muscle groups are fixedly connected to the device housing, and the moving ends are connected to the guide cylindrical rod through the rigid thin plate. The guide cylindrical rod is slidably assembled in the guide groove of the device housing. The docking adjustment assembly includes multiple sets of rotatable hooks, which are rotatably mounted on both ends of the guide cylindrical rod and can be manually engaged and disengaged from the traction cylindrical rod.

3. The auxiliary exercise device according to claim 2, characterized in that, Each group of pneumatic artificial muscles contains 120 pneumatic artificial muscles, which are arranged in 6 layers and 12 columns. The moving ends of all pneumatic artificial muscles in the same group are fixed to a rigid thin plate to achieve synchronous deformation. The pneumatic artificial muscle adopts a transversely supported corrugated densely packed multi-cavity soft pneumatic drive structure. Under normal pressure, it can passively extend under external force to provide motion resistance; under positive pressure, it can expand and actively extend to provide thrust; and under negative pressure, it can actively contract to provide tension.

4. The auxiliary exercise device according to claim 3, characterized in that, The pneumatic artificial muscle group adopts a symmetrical partitioned drive structure, with the i-th column and the 13-i-th column of pneumatic artificial muscles as an independent drive unit, where i is an integer from 1 to 6. The same drive unit applies a pneumatic drive signal synchronously, so as to realize the graded and flexible adjustment of the output force of the pneumatic artificial muscle group while ensuring the symmetry of the output force.

5. The auxiliary exercise device according to claim 2, characterized in that, Both the guide chute and the traction chute are arranged parallel to the bottom surface of the device housing. The guide chute is used to limit the direction of extension and contraction of the pneumatic artificial muscle group, ensuring the consistency of deformation and the concentration of force of all pneumatic artificial muscles. The length of the traction chute is less than the length of the guide chute, which limits the maximum effective extension stroke of the pneumatic artificial muscle and makes the direction of movement of the flexible belt coaxial with the direction of extension and contraction of the pneumatic artificial muscle.

6. The auxiliary exercise device according to claim 2, characterized in that, The lengths of the two sets of flexible bands are matched to the upper limb flexion-extension limit settings; In the initial extended state, the upper flexible band adapts to the initial undeformed state of the artificial muscle group, while the lower flexible band keeps the corresponding artificial muscle group in a fully extended state. In the maximum flexed state of the upper limb, the roller winds around the upper flexible band to keep the corresponding artificial muscle group fully extended, and the roller releases the lower flexible band to keep the corresponding artificial muscle group back to its initial undeformed state. Through the synchronous rotation of the forearm support plate and the roller, the linkage and matching of the upper limb flexion and extension movement and the pneumatic artificial muscle extension and contraction deformation are achieved.

7. The auxiliary exercise device according to claim 1, characterized in that, The pneumatic control system includes an electrical signal control module and a dual-path symmetrical pneumatic transmission module. The electrical signal control module includes a host computer, a microcontroller, a switching power supply, and an NMOS module. The dual-path symmetrical pneumatic transmission module includes a pump that can be used for both pumping and discharging, a two-position two-way solenoid valve, a pneumatic buffer bottle, a pneumatic sensor, a pneumatic on / off valve group, and a pneumatic tube. The switching power supply converts household electricity into 24V DC power to power the microcontroller and NMOS module; the host computer imports the preset target air pressure waveform program into the microcontroller, and the microcontroller outputs a PWM wave to drive the pump and the two-position two-way solenoid valve through the NMOS module; the air pressure sensor collects the air pressure signal in the air path in real time and feeds it back to the microcontroller, and the microcontroller achieves accurate tracking of the target air pressure waveform by the air path air pressure through PID feedback control.

8. The auxiliary exercise device according to claim 7, characterized in that, The dual-path symmetrical pneumatic transmission module independently corresponds to two sets of pneumatic artificial muscle groups, wherein any single-path air path structure in the dual-path symmetrical pneumatic transmission module is as follows: The air inlet and outlet of the pump are connected to two sets of two-position two-way solenoid valves via a three-way connector. The two two-position two-way solenoid valves on the air pump inlet side are connected to the main air port of the air circuit on / off valve group, and the other is connected to the outside atmosphere. The two two-position two-way solenoid valves on the air pump outlet side are connected to the main air port of the air circuit on / off valve group, and to the outside atmosphere. The gas buffer bottle and the pressure sensor are connected in series in the gas path between the two-position two-way solenoid valve and the gas path on / off valve group via a three-way connector.

9. The auxiliary exercise device according to claim 7, characterized in that, The air circuit on / off valve group consists of 12 manually operated valves arranged in 2 rows and 6 columns. The 6 columns of valves correspond to the 6 independent drive units of the pneumatic artificial muscle group. Each manually operated valve controls the air circuit on / off of 12 pneumatic artificial muscles and can independently adjust the working status of each drive unit.

10. The auxiliary exercise device according to claim 7, characterized in that, The pneumatic control system can achieve continuous positive and negative adjustment of air pressure, and suppress air pressure fluctuations caused by the operation of air pump and solenoid valve through air circuit buffer bottle, thereby improving air pressure control accuracy. By controlling the on / off state of the air circuit valve group and adjusting the positive and negative air pressure, the tensile stiffness of the device can be adjusted over a wide range. The maximum tensile stiffness is the total stiffness when both sets of pneumatic artificial muscle groups are fully contracted under negative pressure, and the minimum tensile stiffness is the negative stiffness when both sets of pneumatic artificial muscle groups are fully extended under positive pressure, which can be adapted to the resistance training and passive assisted training needs of patients with different muscle strengths.

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