Research On Hand Function Rehabilitation System For Stroke Based On Thermal Stimulation And Functional Electrical Stimulation

In recent years,the number of stroke patients with hand dysfunction has increased year by year,which brings a great burden to individuals and society.Thermal stimulation and functional electrical stimulation are common methods for the rehabilitation of stroke,which can promote the recovery of muscle spasms,sensory disturbance,paralysis,and other symptoms,respectively.However,the thermal stimulation rehabilitation equipment used in the clinic has problems of inaccurate temperature control and inconvenient operation,and there are few studies on the combined use of the two methods.Therefore,the rehabilitation mechanism and system of thermal and functional electrical stimulations are studied in this paper,aiming to accumulate key technologies for improving the rehabilitation efficiency of hand function.The main works are as follows:(1)Analysis of rehabilitation mechanisms: the rehabilitation mechanisms of thermal stimulation and functional electrical stimulation for stroke patients are summarized based on research at home and abroad.Then the feasibility and advantages of the integration of the two methods are analyzed,and the integration strategies of the two methods are proposed.(2)Design of wearable hand function rehabilitation system: based on the overall demand analysis,the wearable thermal stimulation rehabilitation subsystem and the surface functional electrical stimulation rehabilitation subsystem were designed,respectively.Firstly,the modeling and simulation of the heat transfer during contact between the human skin and the Peltier element were carried out,laying the theoretical foundation for thermal stimulation.On this basis,the hardware,software,temperature control algorithm,and stimulation modes were designed,and spatiotemporalvarying thermal stimulation paradigms were proposed.Then a wearable thermal stimulation rehabilitation subsystem with a 7×5 stimulation array was developed,which can quickly,accurately,and flexibly control the stimulation temperature and area and has the advantages of portability and multiple stimulation modes.Secondly,according to the rehabilitation mechanism of functional electrical stimulation,a wearable surface functional electrical stimulation rehabilitation subsystem was designed,which has multi-channel array electrodes and adjustable stimulation parameters and can find the best stimulation point.Finally,based on the design of the two subsystems,their hardware and software were integrated to obtain a wearable hand functional rehabilitation system that can realize the fusion stimulation of thermal and functional electrical stimulations.(3)Prototype implementation and experimental research: Prototype fabrication and experiments were carried out based on the design of the rehabilitation system.Firstly,we performed the performance test experiments of thermal and functional electrical stimulations.The results verify the rationality of the system design.This system can achieve various thermal stimulation modes,including constant temperature stimulation,spatial stimulation,and temporal stimulation.Besides,it can generate accurate dual-channel functional electrical stimulation pulses.Secondly,thermal stimulation experiments were carried out on healthy people to verify the effectiveness of the system’s thermal stimulation modes on the hand’s skin.At the same time,the temperature perception characteristics of the skin of the hand were explored.The results show some new phenomenons:temperature ladders of 6 °C and above can achieve high accuracy;the palm has a stronger temperature perception ability than the fingers;the homogenization of thermal sensation will cause perception illusion when different regions of the palm are stimulated by different temperatures;the temperature perception interference between the left and right hands is very weak;the non-dominant hand has a lower degree of homogenization of thermal sensation than the dominant hand;the weight of the index finger is higher than that of the middle finger in the process of temperature perception,etc.Finally,functional electrical stimulation experiments were also performed on healthy people,and it proved that the rehabilitation system could make the wrist bend and extend,ring finger bend,three-finger bend,and four-finger extend.At the same time,the results show that the stimulation intensity required for extension is much higher than that required for bend,indicating that the wrist and finger flexors are easier activated by electrical stimulation than the wrist and finger extensors.These experiments laid the foundation for applying the rehabilitation system to the hand function rehabilitation of stroke patients.