On the feasibility of a moving support for surgery on the beating heart

Abstract

In this paper the use of a heart-tracking hand support is proposed to allow coronary artery bypass grafting surgery to take place on the beating heart. Requiring only a three-degree-of-freedom motion platform that tracks a point on the surgical site, this method eliminates the tissue damage associated with the use of physical heart stabilizers and provides a much cheaper alternative to six-degree-of-freedom masterslave systems. To demonstrate the feasibility of such an approach, a motion platform with a motion range and frequency typical of coronary motion was designed and built. A task typical of suture placement was executed on this platform by twenty six subjects, while (i) the platform was stationary, (ii) the platform was in motion with the subjects’ hands attached to it, and (iii) the platform was in motion but the subjects’ hands were not attached to it. This system simulates the use of a motion tracking platform with perfect tracking performance. Mono and stereo vision systems were also mounted to the platform to provide subjects with a visually stable view. Accuracy and task completion time were measured. Relative to the stationary platform case, only a 10% loss of accuracy and 40% increase in completion time were noted when the platform was in motion but the subjects’ hands were attached to it. When the hands were not attached, a significantly higher 50% loss of accuracy and 100% increase in task completion time were noted. Task completion time was improved when a visually stable view was also provided, but accuracy results were inconclusive due to problems with the vision systems used.