A 4-dof haptic device for hysteroscopy simulation

In minimal-invasive surgery surgeons are generally confronted with complex scenario and sometimes they have to overcome unexpected pathologies or life-threatening injuries. Therefore there is a demand for realistic training without risk to the patient. Since a decade ago there have been research activities on virtual reality surgery simulators with haptic feedback with the goal to provide an alternative to traditional training methods on animals or cadavers. Haptic feedback is a key feature for every surgery simulator for the training of hand-eye coordination. In this paper a 4-dof haptic device is presented for hysteroscopy, the examination and treatment of the uterine cavity through the vagina. Specifications are presented, and kinematics as well as force transmission are analyzed. The realized prototype, result of a systematic design process, is based on a 2-dof spherical manipulator with low inertia and a 2-dof serial extension, which allows the use of slightly adapted original instruments. With difference to common surgery simulators tool insertion and complete removal can be performed. The performance of the prototype is shortly discussed.