DFORCE: Delayed FOrce ReferenCE control for master–slave robotic systems

The acceptance of master–slave robotic teleoperated applications in the medical field is related not only to the accuracy and precision of the robotic systems but also to the haptic features. Indeed, the capability to render a good haptic feeling, hence the sensation to drive the real surgical tool, is necessary for reaching an effective interaction between surgeon and robotic system. In this paper an innovative controller for master–slave haptic systems for neurosurgery has been developed by getting inspiration from force reflecting controllers and non-time based control schemes. This new DFORCE (Delayed FOrce ReferenCE) controller is founded on the basic idea to control the position of the device through a system that can generate forces on the master side only when the surgeon is grasping the haptic handle. Thus, when the surgeon is not grasping the haptic handle and external forces are present, the system remains stable. The haptic sensation, the stability and the readiness of the system have been studied and a tuning procedure proposed. Moreover, simulated and experimental tests on a test-bed master system and a haptic master–slave interface for neurosurgical operations have been carried out in order to demonstrate the effectiveness of the controller.