Optimization of a pneumatic balloon tactile display for robot-assisted surgery based on human perception

Robot-assisted surgery is characterized by a total loss of haptic feedback, requiring surgeons to rely solely on visual cues. A compact, flexible, and lightweight pneumatic balloon tactile display has been developed suitable for mounting on robotic surgical master controls. The tactile display consists of a molded polydimethylsiloxane substrate with cylindrical channels and a spin-coated silicone film that forms the array of balloons. Human perceptual studies were conducted to determine the optimal diameter, spatial resolution, and temporal resolution of the balloon actuator design. A balloon diameter of 3.0 mm provided the highest average accuracy ( >or= 95%) while offering five detectable inflation levels. Spatial accuracy in a two-actuator discrimination task reached 100% with 1.5 mm edge-to-edge spacing, and the accuracy of determining the order of two successive stimuli was greater than 90% when the time separation was 100 ms. Design optimization based on the results from this study enables the described tactile display to provide the effective tactile feedback that is otherwise unavailable during robotic surgery.