A General-Purpose 7 DOF Haptic Device: Applications Toward Robot-Assisted Surgery

A 7 DOF haptic device has been designed and developed with applications towards robot-assisted minimally invasive surgery. The device consists of four degrees of force feedback (X, Y, Z, and grasping) capability and seven degrees of position feedback capability. It has a closed kinematic chain with two halves (user interface and spatial mechanism) that connect together via a universal joint. The user interface contains four degrees of position feedback, namely, the roll, pitch, yaw, and linear motion of the hand and forearm. In addition, a grasping mechanism with two thimbles mounted at the end of the user interface provides force feedback to the fingers of the user. The spatial mechanism provides force feedback to the user interface through a universal joint located at the grasping mechanism. This paper presents the design and development of this haptic device. In addition, a kinematic and workspace analysis of the device has been completed to compute the position of the slave robot and end-effector tool. Friction estimation has been presented to enable a higher transparency of the haptic device. Finally, a simulation of needle insertion into soft tissue was developed to test the device.