New Hardware: Design, Models and Analysis

To achieve the results described in the previous chapters, it was necessary to ground our logical statements by making precise measurements of the surrounding environment, to determine the position of the instruments and of the targets, to assess the interaction with the tissues and to make predictions on the instrument behavior. Some of these measures were obtained by standard instruments, as described in Chap. 7, whereas in other cases new instruments were designed, simulated and developed to address the specific needs of the ARS project. Similarly, instrument performance would depend on their interaction with the environments and an analytical model could provide useful indication on how to interpret the obtained results. In this chapter we summarize the study of the interaction and measurements of surgical instruments with the anatomical tissues. In fact, an analytical model can help assess the interaction accuracy by determining whether the instrument is subject to some, albeit small, deflections as summarized in Sect. 1. This analysis was tested in simulation and experiments, but the lack of time prevented their integration in the experimental surgical system. Furthermore, two sensing methods and their hardware implementations were developed to address different shortcomings of the robotic instruments for minimally invasive surgery: one measures the electric properties of the tissues, in Sect. 2, the other measures the internal deflection of the surgical instrument in Sect. 3. Both properties give indications about the type of tissue the instrument is interacting with, and about other physiological properties, such as vascularization and density.