Study on a miniature robotic system for active monitoring in the human respiratory tract.

A three degrees-of-freedom inchworm-type robot is presented for miniature endoscope inspection in the human respiratory system. The robot is actuated with pneumatic artificial muscle and clamped by two air chambers. The robot's extra resistance in the human trachea is analysed in detail and the dynamic model of the robot is built. In order to solve the problems of low stiffness and the nonlinear movement characteristic of the pneumatic robotic system, a fuzzy wavelet neural network controller is proposed to control the robot position servo system using the principle of pulse width modulation. Simulation and experimental results both demonstrate that the training of the fuzzy wavelet neural network controller is faster and the control quality is effectively improved. The monitoring experiments had been done in a swine trachea during mechanical ventilation, and the miniature system can dynamically measure respiratory parameters.