Automatic Adjustments of a Trans-oesophageal Ultrasound Robot for Monitoring Intra-operative Catheters

Abstract

3D trans-oesophageal echocardiography (TOE) has become a powerful tool for monitoring intra-operative catheters used during cardiac procedures in recent years. However, the control of the TOE probe remains as a manual task and therefore the operator has to hold the probe for a long period of time and sometimes in a radiation environment. To solve this problem, an add-on robotic system has been developed for holding and manipulating a commercial TOE probe. This paper focuses on the application of making automatic adjustments to the probe pose in order to accurately monitor the moving catheters. The positioning strategy is divided into an initialization step based on a pre-planning method and a localized adjustments step based on the robotic differential kinematics and related image servoing techniques. Both steps are described in the paper along with simulation experiments performed to validate the concept. The results indicate an error less than 0.5 mm for the initialization step and an error less than 2 mm for the localized adjustments step. Compared to the much bigger live 3D image volume, it is concluded that the methods are promising. Future work will focus on evaluating the method in the real TOE scanning scenario.