Beyond Heart Transplantation: Potentials and Problems of the Shape Memory Alloy Fibers in the Treatment of Heart Failure

ASAIO journal (American Society for Artificial Internal Organs: 1992) (Impact Factor: 1.52). 01/2014; 60(3). DOI: 10.1097/MAT.0000000000000054
Source: PubMed


Heart failure can be treated with devices that mechanically support the circulation. The improvement of these devices would benefit many patients, especially those refractory to maximal pharmacological treatment and ineligible for heart transplantation. This study examined whether the shape memory alloy fibers, which are fibers that contract when electric current flows through them and relax passively when that flow is interrupted, can be wrapped around the failing heart and assist in its pumping action. A band of shape memory alloy fibers was wrapped around a silicon cylindrical chamber which simulated a dilated heart and its pumping action was tested in a circulatory mockup. This rudimentary device was innovatively controlled by pulse width modulation. The band was made of only 6 fibers but yet produced the considerable pressure of 20mmHg and a stroke volume of 11.8ml with modest energy demands. A shape memory alloy device could assist a severely failing heart but there are limiting factors to overcome before designing highly effective devices.

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