Testing repeatability of forces when using neurosurgical spatulas

Virtual reality systems seems to be useful for training the use of brain spatulas without damaging brain tissue but the success of such a system is dependant on the human ability to discriminate pressures applied with the spatula. This paper describes an experiment designed to explore some central issues related to this ability: are surgeons better than laypeople, are the abilities in Virtual Reality (VR) and real world (RW) comparable, and will visual feedback enhance the ability. A group of surgeons and a control group of laypeople were tested in VR and RW. The results showed that surgeons performed better than the control group in RW but worse in VR, and that visual feedback improved the surgeons' abilities more than the control group. The results indicated that visual feedback is important for the success of such a virtual training system.