I. Introduction
Haptic sensations are essential for many teleoperation tasks. Minimally invasive surgery is an emerging field for such telerobotics systems. Such teleoperated surgical robot systems offer surgeons magnified 3D HD vision, various surgical instruments with better dexterity than human hand and enhanced ergonomics [1]–[3]. However, one current concern is the lack of force feedback or haptic (touch) sensation available to the surgeon for safe tissue manipulation, making it possible for a surgeon to cause tissue damage by inadvertently applying excessive force to tissue. The surgeons base such crucial medical decisions on their perception and differentiation of the tissue’s stiffness [4]. Stress injury from surgical forceps may result in pathological scar tissue formation, bleeding, adhesions and loss of bowel motility [5], And organs manipulated during MIS surgery without haptic feedback that may be injured include liver, small bowel and ureter. The lack of haptic feedback is regarded as a limiting factor in existing master-slave surgical robot system [6]–[9].