ORIGINAL ARTICLE Feasibility of infrared tracking of beating heart motion for robotic assisted beating heart surgery Saeed Mansouri 1 | Farzam Farahmand 1,2 | Gholamreza Vossoughi 1 | Alireza Alizadeh Ghavidel 3 | Mostafa Rezayat 2 1 Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran 2 RCBTR, Tehran University of Medical Sciences, Tehran, Iran 3 Heart Valve Disease Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Correspondence Farzam Farahmand, Mechanical Engineering Department, Sharif University of Technology, Azadi Avenue, Tehran, Iran. Email: farahmand@sharif.edu Funding information Iran National Science Foundation; Research Centre for Biomedical Technologies and Robotics, Grant/Award Number: 29929; Rajaie Cardiovascular Medical and Research Centre Abstract Background: Accurate tracking of the heart surface motion is a major requirement for robot assisted beating heart surgery. Method: The feasibility of a stereo infrared tracking system for measuring the free beating heart motion was investigated by experiments on a heart motion simulator, as well as model surgery on a dog. Results: Simulator experiments revealed a high tracking accuracy (81 μm root mean square error) when the capturing times were synchronized and the tracker pointed at the target from a 100 cm distance. The animal experiment revealed the applicability of the infrared tracker with passive markers in practical heart surgery conditions. Conclusion: With the current technology, infrared tracking with passive markers might be the optimal solution for accurate, fast, and reliable tracking of heart motion during robot assisted beating heart surgery. KEYWORDS accuracy assessment, heart motion simulator, heart motion tracking, in vivo animal experiment, infrared tracker 1 | INTRODUCTION Coronary artery bypass graft (CABG) surgery is one of the most prev- alent treatments in heart clinics, in which blocked areas of coronary arteries are bypassed with blood vessels from other parts of the body. In the traditional method for CABG, i.e. on‐pump surgery, a heart‐lung machine is used to stop the heart, allowing the surgeon to perform the surgery on a still heart. However, it has been reported that on‐pump CABG might have detrimental effects on the function of the nervous, respiratory and urinary systems, and lead to prolonged recovery time. 1 Beating heart or off‐pump CABG is an alternative to on‐pump surgery, in which a heart stabilizer is employed to confine the heart motions locally during surgery. This method is now frequently utilized by experienced surgeons, manually or by using robots, to treat patients of higher risk. Robotic assisted off‐pump CABG procedures are carried out using two defined surgical techniques: robotic assisted totally endoscopic coronary artery bypass (TECAB off‐pump); and robotic assisted anastomosis through minimally invasive direct coronary artery bypass (robotic MIDCAB). 2-7 However, in spite of using heart stabilizers, the surgical procedure is challenging, considering the fact that the residual heart motion is still significant 8 in comparison with the 100 μm spatial precision required for CABG. 9,10 More importantly, there are reports that heart stabilizers might cause tissue damage and rupture of the fine coronary arteries, due to applying large forces on the heart surface. 11 Following the great advancements in robotic surgery technology, a robotic assisted freely beating heart surgery (RAFBHS) technique has been conceptualized in recent years that can potentially resolve the problems confronted in manual and robotic off‐pump CABG. This technique, which can be considered as a further development of the robotic MIDCAB, uses the limited open access to the heart surface, available in MIDCAB, to track the free heart motion using a contact or non‐contact method. The heart motion is then mimicked by the surgical arm, using a receding horizon model predictive controller implemented in a trajectory following control scheme, 11,12 to com- pensate the relative motion between the surgical instruments, attached to the arm, and the heart surface. As a result, the surgery is performed practically on a still heart, with a stabilized view of Received: 23 February 2017 Revised: 3 September 2017 Accepted: 5 September 2017 DOI: 10.1002/rcs.1869 Int J Med Robotics Comput Assist Surg. 2017;e1869. https://doi.org/10.1002/rcs.1869 Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/rcs 1 of 12