Energy-efficiency of Cardiomyocyte Stimulation with Rectangular Pulses
Martin Laasmaa, Pengfei Lu, Mladen Veletić, William E Louch, Jacob Bergsland, Ilangko Balasingham, Marko Vendelin
Sci Rep, 2019 Sep 16; 9(1): 13307.
- PMID: 31527628
- DOI: 10.1038/s41598-019-49791-w
Significance
Pacemakers must stimulate heart cells reliably while conserving battery power. This published paper tested whether brief sequences of rectangular electrical pulses could reduce the energy needed to activate individual cardiomyocytes. Multiple pulses lowered the voltage threshold for stimulation but did not lower total energy use compared with a single pulse. Two short pulses separated by a brief interval matched the energy requirement of one short pulse while requiring less voltage. The findings show that pulse sequencing may help when lower stimulation voltage is desirable, but it is not an energy-saving strategy on its own.
Abstract
In cardiac pacemaker design, energy expenditure is an important issue. This work aims to explore whether varying stimulation pulse configuration is a viable optimization strategy for reducing energy consumption by the pacemaker. A single cardiomyocyte was used as an experimental model. Each cardiomyocyte was stimulated with different stimulation protocols using rectangular waveforms applied in varying number, in short succession. The amplitude, the width of each pulse, and the interval between consecutive pulses were modified. The application of multiple pulses in a short sequence led to a reduction of the threshold voltage required for stimulation when compared to a single pulse. However, none of the employed multi-pulse sequences reduced the overall energy expenditure of cell stimulation when compared to a single pulse stimulation. Among multiple pulse protocols, a combination of two short pulses (1 ms) separated with a short interval (0.5 ms) had the same energy requirements as a single short pulse (1 ms), but required the application of significantly less voltage. While increasing the number of consecutive pulses does not reduce the energy requirements of the pacemaker, the reduction in threshold voltage can be considered in practice if lower stimulation voltages are desired.