In-vivo studies on PDMS-embedded fiber Bragg grating based smart laparoscopic grasper

Minimally invasive surgeries are often associated with the risk of tissue damage due to improper force feedback mechanisms to notify surgeons regarding the force thresholds. This work evaluates the grasping forces during tissue handling to offer force feedback and assist surgeons during tissue manipulation. A polydimethylsiloxane embedded fiber Bragg grating sensor was developed and integrated at the tip of the laparoscopic grasper to measure the grasping force. Simulation studies have been performed to investigate the performance of the embedded grating sensor. The sensitivity of the sensor embedded within polydimethylsiloxane was found to be around 31.4 pm N-1 which was better compared to that of a silicone embedded counterpart. In-vivo studies were performed with soft tissue phantoms prepared with silicone rubber interspersed with different concentrations of mineral oil. Experimental results reveal a decrease in the peak wavelength shift as the tissue gets softer which is consistent with the nature of grasping force for softer tissues.