A Flexible Surgical Robot with Hemispherical Magnet Array Steering and Embedded Piezoelectric Beacon for Ultrasonic Position Sensing
Feng Ju, Xin-feng Gu, Bai Chen, Xiaoyu Sun, Zhiyuan Shen, Bruce W. Drinkwater, Liping Ding
Abstract
This article proposes a flexible surgical robot featuring strong magnetic steering achieved by a hemispherical magnet array actuation, and high‐accuracy ultrasonic position sensing achieved by a beacon total focusing method (b‐TFM). The hemispherical magnet array with magnetic focusing is described and its array parameters are optimized through finite element analysis to increase the magnetic field for actuation. The magnetic field strength at 100 mm for the array with the same mass as the cylindrical magnet is about 1.8 times higher than that of the cylindrical magnet. Using the magnet array actuation, the flexible robot exhibits the capability of agile steering to navigate along a predefined trajectory. In addition, a 1 mm × 1 mm lead zirconate titanate (PZT) patch is embedded into the tip of the flexible robot as a beacon for b‐TFM ultrasonic imaging to detect the position of the robot. Therefore, the entire navigation process can be executed under the supervision of the ultrasonic position sensing system, and the maximum error is 0.8 mm when the steering radius is 100 mm.