10.4.1. Introduction

The original application for the dVRK/da Vinci is RAMIS (Robotically Assisted Minimally Invasive Surgery). For this application, it makes sense to use the same convention for the system coordinates on both the surgeon’s and patient’s sides. The ISI (Intuitive Surgical Inc) convention expects that X points to the left when viewed from the stereo display, Y should point up and Z away from the user. Using the same convention greatly simplifies the implementation of teleoperation tasks. From there it is important to always define the arm motions with respect to the task:

• MTMs with respect to the stereo display

• PSMs with respect to the camera coordinate systems

To make sure coordinate systems are properly aligned, one needs to first find the transformation between the arm base frame and the task frame (display or camera) using either a kinematic chain (SUJ) or a registration method. Once this transformation is found, it has to be used as base frame for the arm.