Research And Development Of A Quantitative Vibration Perception Threshold Testing System

Quantitative vibration perception threshold system (VPT) is developed, which is part of the Quantitative Sensory Testing systems (QST). QST is used to check the disease of peripheral nerves. Many diseases, such as diabetes, can result in the abnormity of peripheral nerves. So such kind of diseases can be forecasted through QST.First, the physiological basis of VPT is introduced. Then the thesis discusses in detail the psychophysical knowledge of the threshold detecting method, especially the transformed-rule up and down method and forced-choice method. The system can efficiently filter subjective effect and has double-blind auto-testing function.The emphasis of the paper is on the development of the Quantitative vibration perception threshold system. In the 4th chapter the hardware of the system is introduced, which includes the power supply module, microcomputer, vibration stimulating driver, signal sample driver and other peripheral circuit modules. In 5l chapter, the software of the system is introduced, which includes the initialization module of system, management modules of LCD and keyboard, control and output modules of the vibration, sampling and processing module of acceleration signal and module for calculating threshold.In 6th chapter, two experiments are investigated. The first experiment shows that the VPT system is good in stability and repeatability. The second experiment explores the stochastic resonance phenomenon in human sensory system. It can conclude from the result that electrical noise may enhance the ability of humans to detect sub-threshold vibration stimulus.