Position: Research Scholar AND Research Fellow in Robotics and Haptics
Location: Harvard Biorobotics Laboratory, Harvard John A. Paulson School of Engineering and Applied Sciences, USA AND Institute for Intelligent Systems Research and Innovation (IISRI), Deakin University, Australia
Period: 2015 – 2016
This modular force feedback enabled minimally invasive surgery instrument is able to measure tip/tissue lateral interaction forces as well as normal grasping forces. This will help restore sense of touch in robotic assisted minimally invasive surgery operations in order to characterise soft tissues of varying stiffness. The instrument has also the capability to adjust the grasping direction inside the patient body during the operation. The modularity feature of the proposed instrument makes it interchangeable between various tip types of different functionalities (e.g. cutter, grasper, and dissector). In order to measure the tip/tissue lateral and normal interaction forces, strain gages were incorporated into the instrument tube and the actuation and transmission module. The mathematical formulation of a fenestrated insert is presented and its non-linear behavior is studied. A series of finite element analysis of components with strain gages were performed to gain an understanding of the actual magnitude of surface strains where gages are located. The strain gage bridge configurations were calibrated and results are studied that show the monotonic responses of the strain gage configurations. Series of experiments were conducted and results are analysed that verify the capability of the proposed instrument in accurately measuring sideways probing forces and characterising artificial tissue samples of varying stiffness.