Time for green pacemakers: renewable energy sources to power implanted cardiac devices.

摘要

There have been dramatic advances in the technology of implanted cardiac devices since the first pacemaker was implanted in 1958. Implantable cardioverter-defibrillators (ICDs) can prevent sudden cardiac death from ventricular arrhythmias, and cardiac resyn-chronization therapy can optimize the hemodynamic performance of the failing heart. Advances in the hardware technology have transformed them from large 'brick-sized' devices (250 cc), implanted in the abdomen, to small (8 cc) ones that are implanted subcutaneously in the pectoral area of the chest wall. Most of the size reduction has come through advances in battery and capacitor technology, with optimized longevity and more reliable decay curves. Over the last 5 years, the size reduction has reached steady state. In spite of this, greater demands are made on battery power. In pacemakers, we have seen increasing numbers of algorithms to emulate normal physiology.