Research On The Collection Of Motion Information Of The Elbow Joint Control Muscle Group Based On Piezoelectric Sensor

Elbow joint connecting with the upper hand, wrist and shoulder joint play an important function of complex structure, is very important to the human body. Elbow joint is similar to the compasses of upper intermediate joints, connecting the upper arm and forearm. Its main function is to stretch, flex and rotational movement of the forearm, and involve with the shoulder joint, so that the hands from the body can stay in any position and move freely in certain space, so it can full play the function of the hands. The importance of the elbow joint, is often reflected in people's daily life. Such as eating food, elbow need unbend and pronation, hand can grip the food, then elbow flex after spinning, hand the food to shoulder and mouth, food can get into the mouth; And as in doing sports, such as tennis, basketball, golf, technique specification in not normative, the early stage of the training is overweight, insufficient warm-up and upper limb muscles fatigue often trigger elbow injury and upper limb dysfunction, one of the very typical representative is the tennis elbow (humerus condyle inflammation) and golf elbow (humerus condyle inflammation).Research has proved that, in a way the safety of the elbow joint is controlled by the surrounding muscles, so researching the controlling muscle group around the elbow joint in the pathological diagnosis, rehabilitation medicine, physical education and sports science and other fields have a considerable impact, at the same time also have a positive effect to elbow joint fatigue and injury prevention and lesions.The information collection of elbow's movement information in the process of human controlled muscle movement, is the premise to study controlled muscle group. For now, the muscle movement information collection is mainly based on the electromyographic signal, but it need to cut the needle electrode into the muscles in order to obtain the electromyographic signal of muscle fibers. Adopting the surface electrode using multi-channel semg has no traumatic, the electromyographic signal acquisition has improved a lot, but they are very vulnerable to skin conductivity and temperature changes, the shortcomings of ecg signals such as interference. In addition, the spectrum distribution of electromyographic signal is very narrow and the signal value is very weak, also hard to ensure the consistency and reliability in acquisition, and acquisition environment demand is extremely high, the equipment is expensive, in the practical cases collected reliable signal is more difficult.Based on the deficiencies of current elbow control muscle movement about information acquisition, this paper studies a new sampling method:through the real-time acquisition of piezoelectric information of elbow movement control muscle group, to accurately extract the kinematical mechanics parameters, which can quantitatively show kinetics and biomechanical characteristics of muscle group, to get some movement information about the elbow movement trend at this point by collecting the piezoelectric information of elbow control muscle group movement. This paper shows the PVDF piezoelectric sensor design and production of elbow muscle control electric information collected. Soft, thin, light weight, corrosion resistance and impact resistance are the advantages of PVDF and it's a good choice in dynamic environment to use. Through the test and analysis of the simulation results, simply supported circular structure is identified as sensor arm beam structure. Paper also designs the signal conditioning circuit, the final performance test results show that when the pressure between 50N and 500N, the output of the sensor is normal; Excitation frequency is about 750Hz, the sensor response frequency deviation is smallest; when the excitation frequency exceeds 2000Hz or less than 6Hz, there will be more than 5% deviation of frequency response. Through the study of elbow's clinical anatomy, design the layout scheme of sensor array, through the special tights to fix. Using dumbbells arm flexion movement to tests dynamic, proves that the method can real-time get the motion information of elbow movement control muscle group, and has the advantages of reliable, economic and practical.