A Laminated Continuum Robot With Gripping Force-Sensing Forceps for Robot-Assisted Minimally Invasive Surgeries

Minimally invasive surgeries (MISs) or natural orifice transluminal endoscopic surgeries (NOTESs), such as the transurethral resection of bladder tumor (TURBT), require the surgical robot to be miniaturized to perform surgical procedures in narrow spaces. However, miniaturization of surgical robots poses problems in its fabrication and sensor integration. In this article, a miniature continuum surgical robot is proposed with force-sensing surgical forceps, which can be fabricated through a 2-D lamination process and converted into 3-D through folding. This multimaterial laminated structure facilitates the integration of photoelectric sensors into the surgical forceps. Then, the gripping force of the surgical forceps is sensed from the change of the output voltage of the integrated photoelectric sensor. The sensitivity of gripping force to the change of output voltage is 3.6 N/V, and the maximum error during calibration is 0.03 N. The proposed robot and the gripping force sensing method are validated through simulations and experiments, such as gripping and releasing objects of various hardness and heights. It is also validated that the gripping force information could also improve the gripping performance in the object handling experiment and ex vivo porcine intestine gripping experiment.