RESUMO
Objective To develop a shoe-cover-style obstacle avoidance device based on gait detection algorithm for the visually impaired.Methods The device was composed of shoes covers and an electric control box.The hardware involved in MSP430F1132 SCM as the control unit,triaxial accelerometer to measure foot acceleration,ultrasonic sensor to detect obstacles and solar battery for power supply.A gait detection algorithm was proposed to implement a foot motion states detection program,and the motion states included static and moving ones.Results The device executed obstacle detection when'the feet were raised and let down,and obstacle detection were stopped in case the feet were kept unmoving,shaking and hanging.The rate for mis-alarm was decreased and the operation procedure was simplified.Conclusion The device behaves well in timeliness,efficiency,mis-alarm,portability,low cost and easy operation,and thus is worthy studying and practical application.