Development of a 5-DOF force feedback laparoscopic interface for simulation and telesurgery

Laparoscopic surgery reduces recovery time and risk of complications over conventional methods for abdominal procedures, making it particularly suited to battlefield medicine. However, laparoscopy challenges the surgeon to work under many limitations: motion is reflected about the trocar; access inside the body is restricted; visual feedback is generally only 2D; and haptic, or touch, information is reduced. As such, the importance of training for developing sensitivity to the existing haptic cues becomes apparent, and the problem arises of how to distribute the services of relatively few highly trained surgeons to widespread battlefield locations. A force- feedback haptic interface can play a critical role in both of these functions, providing realistic or enhanced sensations to a laparoscopy simulator or a telesurgery system. The work described here was directed at continuing the work of earlier force-feedback systems, which provide up to the first three degrees of freedom (DOF) in laparoscopy (pitch, yaw, and insertion relative to the trocar), toward creating a complete and high-fidelity haptic interface. Careful requirements analysis using data from surgeon interviews, operating room observations, and task analyses, was the basis for specifying the technical attributes and configuration of the new system. The resulting interface offers the surgeon real laparoscopic tools with force feedback to all five degrees of freedom in laparoscopy, using a lifelike torso in which trocar location is easily changed. A light and compact 2-DOF device was developed to supplement one of the available 3-DOF devices, providing the additional forces in tool rotation and gripper feedback. Next year, the system will be integrated into a software stimulation currently in development at the Center for Minimally Invasive Therapy (CIMIT).