Investigation of Multi-Modal Haptic Feedback Systems for Robotic Surgery

The advent of minimally invasive surgery (MIS) led to significant benefits for patients at a cost of increase technical difficulty for surgeons. Robotic minimally invasive surgery (RMIS) was introduced to help eliminate some of the outstanding challenges by introducing improvements such as enhanced 3D vision and additional degrees of freedom. Unfortunately, RMIS resulted in a complete loss of haptic feedback, a problem that has persisted even after more than a decade of technology development.The limitations introduced by the loss of feedback in robotic surgery gave birth to innovations and significant research on haptic feedback systems (HFS). These systems aimed to provide an artificial sense of touch. Researchers have focused on many varieties of feedback technologies, most often relying on one specific feedback modality to help improve performance in a few, limited robotic surgical procedures.This research project set out to investigate multi-modal haptic feedback systems capable of providing benefits for many different robotic surgical applications. Having inherited an existing tactile feedback system designed for reducing crush injuries in robotic surgical procedures, this project implemented various critical enhancements for pneumatic normal force tactile feedback. Improvements to the sensing technology such as design of shear sensing mechanisms helped expand the application of haptics beyond grip force reduction.The development and integration of additional modalities of feedback including kinesthetic force feedback and vibration feedback, and design of a highly configurable software architecture allowed the application of the multi-modal HFS in several different RMIS applications. Evaluation of the system for knot tying in robotic surgery showed significant benefits in reducing suture breakage and improving knot quality. Application of the multi-modal HFS for palpation in robotic surgery helped improve detection non-compressible structures such as tumors and vessels in soft tissue phantoms. Finally, the system improved upon the previously developed unimodal tactile feedback systems with regards to reduction of grip force in RMIS.The results of these investigations highlight the importance of developing multi-modal haptic feedback systems that are able simulate the synergistic relationship between the various feedback modalities involved in real human touch. Robotic surgical systems have long been held back by their lack of comprehensive haptic feedback solutions. Multi-modal haptic feedback systems hold the promise of eliminating this long-standing problem and helping expand the application of robotics in surgical sciences