A new tactile device using magneto-rheological sponge cells for medical applications: Experimental investigation

This work proposes a new tactile device that uses a single magneto-rheological (MR) sponge cell to realize the viscoelastic sensation of real organs. The proposed MR sponge cell can be usefully applied to medical fields to provide tactile information to surgeons who perform robotic surgery and doctors who receive training for practicing surgery with a computer-based simulator. In order to demonstrate the effectiveness of the proposed MR sponge cell, a 3-axis robot is designed and manufactured as an experimental apparatus. Using the robot, the relaxation times and repulsive forces of the MR sponge cell are measured and compared among three animal specimens: pork, pork rind, and pork heart. It is noted that the specimens represent the soft or/and hard tissues of human organs. The relaxation times are obtained from exponential equations based on the measurement data according to the properties of the viscoelastic material. The repulsive forces, normal force, tangential force, and bending moment are determined on the basis of comparison criteria of the beam bundle model (BBM). It is shown that the proposed MR sponge cell can effectively represent different feeling of the sensation of the specimens by applying different magnetic intensity to the cell domain.