Experimentally driven design of a palpating gripper with minimally invasive surgery considerations

A natural extension of current robotic minimally invasive surgery (MIS) is the addition of tactile and kinesthetic feedback, which would give an operating surgeon valuable haptic information about tissue under observation. Identification of haptic properties requires active exploration [1][2]. It is believed that such exploration may be facilitated by a tool capable of replicating the major exploratory procedures (EPs; haptic information gleaning maneuvers) of a surgeon. Such a tool must also fit within the fabrication and other constraints of similar MIS tools. In this paper the requirements of such a gripper are highlighted via experiments with surgeons. The results have been used to develop a 2-finger, 3dof (degree of freedom) gripper based on an inverted closed chain serial manipulator. A primary advantage of this system is its dexterity and compactness, compared to other manipulators. The gripper is shown to be capable of replicating the most frequently observed two-finger exploratory procedures. It is argued that a single tactile sensor is sufficiently useful for a two fingered system and a scaled prototype of the system has been designed to accommodate such a sensor. This system has been designed with later laparoscopic grade manufacture in mind.