Research Of Sensation Acquisition For Prosthetic Hands And Perception Neurofeedback Based On Piezoelectric Sensor Technology

With the development of scientific research, prosthetic technology has also made consider able progress. Myoelectric prostheses and prosthetic EEG is comparatively advanced intelligen t prosthetic of multi-degree of freedom at present. However, these prostheses is still taken mov ement according to predetermined fixed pattern on the control scheme, and prosthetic user can not intuitively get sensory feedback that they are not able to make sensory feedback control, so as that the human-computer interaction is insufficient. This deficiency hindered the further dev elopment of prosthetics. Motor and sensory function are the two major functions of Human han d, and these two functions influence each other.Obtaining tactile and slip signals the prosthetic hands generated in the process of grasping objects, which can effectively improve the efficiency of the prosthetic hand movement, Realizing lossless, and help to firmly grip the object. In order to collect accurate tactile and slip signals, I chose the piezoelectrets film with excellent performance in the study. This material is thin, soft, bendable, has a light weight and high sensitivity characteristics. By selecting film material and conducting piezoelectric technology research to build electret film piezoelectric electrical characteristics of the measuring system and make the sensor package. This sensor is designed for signal conditioning circuit, the circuit comprises a charge amplifier module, low-pass amplifier module, notch filter module and power module. In the design of low pass amplifier module, the use of computer programming technology parameter selection, more scientifically rigorous production circuit.In order to control a prosthetic hand moving, circuitry and signal system has been built, which gets the prosthetic hand sensory feedback signal and extracts features in time domain(TD) and frequency domain(FD). Therefore, two types of signal, the touching signal and the slipping signal, are exacted from the TD and FD features above.General rules of subjects at the limb stump tactile information input has been studied by electrical stimulating the nerve on stump surface. In the experiment using objective index and subjective index mainly solved two problems. One of them is helping amputees get phantom limb sense by activating amputee residual limb through the surface stimulation. The other one is determine the relative optimal tactile information input position.The FMG(muscle force plethysmography) based motion feature recognition experiments have been done. Eight-channel piezoelectric sensor system has been established and the pressure sensor is arranged on a person’s lap to collect FMG signals during different leg motions. Four different movements could be distinguished from each other. The pattern recognition classification accuracy was relatively high. This is bases research of hand FMG studies.