Introduction: Ischemic mitral regurgitation (IMR) predominantly suggests pathology with ventriculo-papillary-mitral complex and has disappointing surgical outcomes and survival rates with conventional repair techniques. Current computational fluid dynamics modeling systems lack the accuracy needed to elucidate fundamental displacement of papillary muscles that can impact leaflet coaptation. We have designed a reciprocative robot with twelve planes of motion to address the kinematics of papillary muscles through the cardiac cycle.
Methods: The three-dimensional modeling of the left ventricular components is provided by two parallel robots that mimic the papillary muscle motion as a combination of translational and rotational motion that model twelve degrees of freedom, as shown in Figure 1. Twelve stepper motors are controlled by a microcontroller on a source code written in C++. The heart rate of the patient is mimicked by adjusting the angular velocity of each motor shaft.
Results: The twin robots successfully demonstrated translational and rotational motion in twelve planes. Altering the twelve independent parameters that define the position of the papillary muscles allows to observe the physiological and pathological effects of left ventricular motion on the mitral valve. By breaking down the source code, we could demonstrate the multiple phases of a cardiac cycle and adjust the time that is spent in each phase with a 4-micron resolution. Data (echo and c-MRI) allows a customized model of motion for each individual patient by accurately mimicking mitral valve leaflet coaptation.
Conclusion: A multiplanar electromechanical construct allows a customized therapeutic solution for individual patients with IMR. It offers unique insight into the pathophysiology of IMR and for designing new sub-valvular therapeutic options.