Haptic Information Gain in Remote Soft Tissue Examination Using a Controllable Stiffness Robotic Probe

Technologies for remote physical examination of patients can transform disaster response operations like Ebola or even to perform preliminary examinations of patients in remote areas. Often general practitioners control the stiffness of fingers during physical examination. Our previous studies show that this stiffness control plays a significant role in haptic information gain in robotic probes. This paper investigates the effect of the stiffness of a probe on remote haptic feedback given via a vibrotactile display. We investigated this effect by asking human participants to press a button when they felt a significant change in the vibrotactile feedback received from a remote soft robotic probe that palpated a soft tissue to identify the location of a hard nodule. We investigated how factors such as the stiffness of the robotic probe, its probing speed and nodule depth affect the accuracy of detecting the location of the hard nodule. We found that the change in stiffness resulted in a change in detection accuracy; furthermore, probing speed showed statistically significant effect on the accuracy of detection. These results indicate that a controllable stiffness probe can be a versatile tool for remote physical examination.