Structure And Control Technology Of The Supple Knee Rehabilitation

Continuous Passive Motion (CPM for short) is the important method at present of rehabilitation training for knee joint injuries sufferer after operation. But the traditional CPM machines are mostly driven by machinery and motor which provide position with high precision but high rigid and only passive motion. It can easily cause secondary damage to patients while training. On the other hand the passive motion can't meet the demand of muscle strength training in the later rehabilitation period. However most clinical observation and statistics shows that: compared with totally passive training, passive training combining with active training after operation can relieve pain and promote functional recovery of the knee joint. So to design a new compliant and active rehabilitation apparatus has great scientific significance and application value.According to these objects, the main contents and achievements in this thesis are summarized as follows:(1) The thesis has put forward for the first time using pneumatic muscle actuator (PMA for short) connecting in series with pneumatic cylinders as the compound actuator to study a new compliant knee joint rehabilitation apparatus. Using the compliance of the PMA has overcome the traditional CPM shortcoming of only providing rigid training. The stroke of PMA is short and could not provide enough stroke to the knee joint, however the pneumatic cylinder has long stoke which can solve this problem. By respectively controlling the pressure of two cavities of the cylinder, the piston can move controllably in the pneumatic cylinder which has realized the active training for the apparatus.(2) In order to control different training demands in different rehabilitation steps, the thesis has researched on the control technology of the rehabilitation apparatus. Through considering the actual condition of the research, the method of using PC with data acquisition card has been chosen. The software of LabVIEW has been chosen to control the sensor and valves. The control module has been built for test in which all the parameters can be adjusted to meet the demands of human-computer interaction. With control program to control the pressure and its change, the apparatus can move periodically and steadily.(3) The research has built the theoretical model of the compliant knee joint rehabilitation apparatus and tested its performance. The experiments show that under the passive motion the maximum turning angle is 82°while 130°under active motion, the apparatus can completed the motion in 25 seconds with speed of 6°per second and acceleration of 2.5°/s~2 when carrying a person of 45kg. which has met the demands of rehabilitation training. Also through tests, the apparatus has been proved to be able to provide both compliance and active motion.The results show that, using PMAs connecting in series with pneumatic cylinders as the new actuator can meet the new demands of compliance and active motion on the rehabilitation apparatus. Also the whole machine is compact and light, it will have great application prospect.