Research of Foot Plantar Pressure Scanning System Design Based on Sensor Array

WANG Mo, FAN Zhuochen, MA Hao, PENG Chen, ZHANG Sixu, WANG Xin’an†

The Key Laboratory of Integrated Micro-systems Science and Engineering Applications, Peking University Shenzhen Graduate School, Shenzhen 518055; † Corresponding author, E-mail: anxinwang@pku.edu.cn

Abstract In order to improve the accuracy of foot plantar pressure acquisition and reduce the influence on the experimenter’s natural gait during the measurement, the improved design of plantar pressure acquisition system and the optimization of sampling timing are proposed, which can effectively reduce the noise interference introduced by the sensor and the circuit system, and finally realize the sampling measurement of large size (71.9 cm × 33.5 cm) and high spatial resolution (2.8/cm2, a total of 6720 sensor units) plantar pressure sensing system with the sampling rate of 100 SPS. The system is used to test in the Department of Rehabilitation in Guangzhou First People’s Hospital. The collection and analysis of foot plantar pressure can be applied to the postoperative gait rehabilitation training, providing effective quantitative data reference for doctors to evaluate the rehabilitation of patients and formulate targeted treatment plans. Key words resistive pressure sensors; sensor array; foot plantar pressure; Sensor calibration; pressure image

足底压力指日常运动活动中人体足部和支撑表面之间作用的压力场[1]。足底压力采集与分析可应用于步行康复训练中, 通过分析患者的步态特征和发力方式, 为医生评估患者康复情况和制订针对性的治疗方案提供有效的量化数据参考[2–3]。

在足底压力采集系统的设计中, 为使实验者尽量按照自然的步态行走, 而不受传感器尺寸的影响,

应尽可能地增大压力感应面积。同时, 为提高压力采集的精度与时间解析度, 对传感系统的空间分辨率和采样率也提出更高的要求。随着传感单元尺寸的缩小和感应面积的增大,传感单元数量呈几何倍数增加, 从而增大了信号处理电路设计的复杂度。该复杂度主要体现在对扫描时序的控制和对系统噪声的消除方面。在扫描时序