Research On The Measurement System Of Human Pressure Distribution State Parameters In Sitting Position

Sit is one of the basic activities of mankind.When people is in a bad sitting state for a long time,some diseases,such as hunchback,lumbar spine disease maybe are caused by body imbalance.Therefore,the measurement of human body pressure state parameters had attracted wide attention.However,the researches were mainly focused on foot pressure measurement and wearable health equipment research,and the study of human pressure distribution in sitting state was very little.In addition,with development of technology,the study of compression sensing theory was increasing.And researchers put forward the concept of distributed compression sensing for the systems with multiple sensor nodes.So an effective monitoring system of body posture pressure based on the flexible tactile sensor-conductive rubber was designed,the main contents of the work are as the following:By comparing the advantages and disadvantages of various pressure sensors,sixty-four conductive rubber filled with carbon black particles were selected as the pressure sensing element of the system.Using the piezoresistive effect,the sensor array converted the human body pressure signal into voltage signal,and then entered the subsequent circuit.In order to simplify the system structure,were selected to collect the 64 signal acquisition channels,and divided the multiple analog switches into two levels.TI's ultra-low power microcontroller MSP430G2553 chip was chosen,which with 10-bit ADC.And the signal was transmitted using a Bluetooth module.The main functions of the host computer were signal processing,including digital filtering,pseudo color scheme and bilinear interpolation method.Based on the second joint sparse model of distributed compression sensing,the sampled value was reduced.Finally,a clear and intuitive human body pressure Distribution image was formed.The experimental results showed that the system could identify the distribution of human body pressure,the stability and resolution was good,and the system could realize real-time measurement and display of human pressure distribution.