Haptic threshold for pulling force feedback on surgeon's fingertip in medical robotic systems

Abstract

Abstract-The human fingertip has very high density of the receptor to accept sense of touch stimulation. The corresponding somatic sensory area in a brain is very large, and considered to be a specialized part for palpation. A lot of haptic display system then have been developed with the investigation of human haptic perception. However, the researches about the human perception for pulling force at grasping, namely static frictional force are limited. This paper investigated it, aiming at a future development of pulling and grasping force feedback system for neurosurgical robotic systems. For the purpose, this paper explored the possibility of displaying pulling force to an index finger during grasping. The absolute and difference thresholds for pulling sense were the targets. The results showed that grasping disturbs the pulling sense, and the sides of index fingertip can be used to display pulling sense, relatively large force, namely scaled force feedback is required for the perception. The results provide an important insight at a hardware and controller design of force feedback systems.

Finger-attachment device for the feedback of gripping and pulling force in a manipulating system for brain tumor resection

“…By using the master-slave manipulation system with the newly developed finger attachment, an examination was conducted to distinguish the difference in the hardness of the gripped material. The Young's modulus of the brain tissue was reported to range from 10 to 50 kPa [26], and the shearing elasticity of the brain tissue was reported to be 5 kPa [27]. Because the Young's modulus was three times larger than the shearing elasticity for the biomaterial, youung's modulus of the brain tissue can be estimated as ~15 kPa.…”