Research On Three-Channel Pulse-Taking System Based On Machine Vision

Pulse diagnosis is the most important part of TCM syndrome differentiation system.In the process of traditional pulse diagnosis,traditional Chinese doctors analyze pulse characteristics according to subjective feelings and long-term practical experience.Therefore,pulse diagnosis should be combined with modern technology to design pulse-taking system,and promote the development of intelligent and standardized pulse diagnosis.Based on the theory of "three regions and nine pulse-takings" in traditional Chinese medicine,this paper designs a pulse-taking system suitable for three regions of wrist pulse.The pulse-taking device uses stm32f030f4p6 chip as a microprocessor,and adopts the effective combination of piezoelectric sensor and membrane sensor to obtain pulse signal and pulse pressure signal respectively.According to the characteristics of sensor output signal,the conditioning circuit is designed.The digital signal is obtained through AD conversion.This system accords with the theory of "three regions and nine pulse-takings" of traditional Chinese medicine pulse diagnosis.It can support independent acquisition of single part and simultaneous acquisition of three parts.In this paper,the machine vision algorithm is used to study the positioning of the three regions.Six stepper motors and guide pairs of lead screw are used to construct the horizontal motion structure of three regions of cun?guan and chi to realize the movement of pulse sensor on the horizontal plane;three motors and guide pairs of lead screw in the vertical direction are used to realize the adjustment of sensors and skin contact.A camera is installed directly above the wrist bracket to obtain the wrist image.Open CV is used to do gray-scale,histogram equalization,skin segmentation,polygon contour fitting,corner detection and other operations to identify the three positions.Based on RS485 communication technology,the stepper motors in the horizontal direction are driven to control the pulse sensor to move to the corresponding position.This paper studies the automatic pressurization technology based on the incremental PID control algorithm.By comparing the advantages and disadvantages of position PID and incremental PID algorithm,it is determined to use incremental PID control algorithm to realize automatic pressurization.The automatic pressurization control strategy is designed and the PID parameter setting method is determined.It is divided into nine stages to pressurize step by step.Three motors in vertical direction are driven to realize the movement of pulse sensor in Z direction and control the contact pressure between pulse sensor and skin.And the best pulse pressure and pulse signal can be accurately obtained by simulating the automatic pulse diagnosis of traditional Chinese medicine.