Prosthetic Socket Comfort Test System Development

The prosthetic socket is the binding part between the artificial prosthesis and the patient's stump,which is responsible for the support and bearing.The rationality of the design and the precision of the manufacture directly affect the comfort and function of the prosthesis.In order to solve the problem of comfort measurement in the prosthetic socket,a multi-parameter comfort measurement system was developed to simultaneously measure the pressure,temperature,humidity and the motion states of prosthetic in the prosthetic socket.The prosthetic socket comfort measurement system consists of distributed pressure measurement module,temperature and humidity measurement module,motion state measurement module,data transmission module,data analysis and storage module and so on.Among them,the pressure measurement module and temperature & humidity measurement module using small sensors,distributed in the prosthetic socket's wall.The motion state measurement module adopts an attitude measuring unit based on the acceleration sensor,which is installed on the outer wall of the prosthetic socket to obtain the motion state information of the prosthetic.The data transmission module wirelessly transmits the sensor data to the data analysis storage module to graphically display the measurement data and the analysis result.To minimize the impact of the measurement system on the prosthetic wear,the distributed pressure measurement module uses the membrane pressure sensor FSR402.Considering the characteristics of output signal of FSR402 sensor,a current/voltage conversion circuit is designed.A multi-sensor data acquisition module is designed based on STM32 microprocessor.The multiplex pressure sensor signals acquired by the built-in AD multiplexer;On the other hand,the data transmission with the host PC through the serial communication.Temperature and humidity measurement using SHT15,which is a two bus serial data communication mode of temperature and humidity integrated sensor.Design the temperature and humidity data acquisition module based on single chip STC89C52.SCM configure and collect data of the temperature and humidity sensors through the serial communication,communicate with the upper PC through the USB data interface.Use MTi sensor to measure the motion state of prosthetic socket.The sensor configuration and data read based on the underlying serial communication protocol,the prosthetic socket motion state of the three-dimensional virtual display in the upper PC interface based on VRML technology.Based on the virtual instrument technology,we use the LabVIEW software to develop the multi-parameter measurement system of the prosthetic socket.The software can realize the collection of pressure,temperature,humidity and gait related parameters.On the other hand,as a human-computer interaction interface,it can achieve the function of data display,analysis,storage and other functions.The preliminary laboratory test shows that the measurement system can provide data for the comfort evaluation of the prosthetic socket,and provide the objective basis for the improvement of the prosthetic socket.