Soft Robotic Dynamic Cardiomyoplasty with Electrically Contractile Artificial Muscle (AHM)

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<h3>Purpose</h3> Ventricular assist devices (VADs) have clinically evolved as a promising alternative for the treatment of end-stage heart failure. The greatest challenges of these devices still remain infections, bleedings and thromboembolic events. Moreover, non-pulsatile blood flow has led to new complications such as formation of arteriovenous malformations with subsequent bleeding in the gastro-intestinal tract and aortic valve regurgitation. Aim of our experimental study was the development of soft electrically contractile artificial muscles wrapped around the heart. This enables a physiological pulsatile flow of the heart and does not require anticoagulation, the main cause of major adverse cardiac and cerebrovascular events in VAD therapy as there is no direct blood contact between the artificial muscle and blood. <h3>Methods</h3> Silver coated nylon (SCN) conductive actuator filaments were fabricated, aligned in a braided fashion and linked together with silicone akin to human striated muscle. Wrapped in layers around lamb hearts with closed mitral valve as a heart sleeve in-vitro, the aortic pressure and contraction rate during upon electrical stimulation of the AHM with 32.5 V electricity was monitored. <h3>Results</h3> After a series of modifications and improvements, in analogy to the human heart stable pressures of 120 mmHg in systole, 80 mmHg in diastole and a mean stimulation rate was 84 /minute could be achieved. <h3>Conclusion</h3> This represents the first successful study demonstrating that an electrically contractile artificial muscle/soft robot can generate pressures and contraction rates necessary to support the left ventricle of the heart.