Robot assisted internal mammary artery detection for coronary revascularisation surgery

This paper presents a semi-automatic robotic system supporting a surgeon in the harvesting of the internal mammary artery (IMA) for an open chested intervention in coronary revascularisation surgery. The versatile surgical lightweight robot MIRO developed at DLR (German Aerospace Center) is used to detect and mark the path of the IMA at the inner side of the thoracic wall. The robot is equipped with a tool combining a Doppler ultrasonography (US) probe and a medical marker pen. The position of the IMA is extracted from the US-images to place the tool above the artery via visual servoing. Additionally, the robot moves the tool in direction of the artery to mark the location of the IMA on it's path. To achieve an ideal contact situation for US-imaging along the whole path the contact force between tissue and probe is controlled according to force measurements based on the internal torque sensors of the robot. The evaluation of the robotic system by an animal experiment shows that the system is capable of robustly detecting the IMA.