Modeling and simulation of solar boost converter to supply power for cardiac pacemakers

This paper discusses the modeling and simulation of DC-DC boost converter in MATLAB/SIMULINK environment for providing sustainable power to implantable cardiac pacemakers. For continuous functioning of implantable cardiac pacemakers, rechargeable batteries are used whose voltage level decreases with the passage of time. Thus, it is essential to have a system which can provide continuous power supply to the pacemakers in order to maintain the proper voltage level of the battery for its smooth operation. A DC-DC boost converter in conjunction with solar energy harvester under the skin can be used as completely implantable power supply to charge the battery of the cardiac pacemakers. The solar radiations of various intensities after penetrating through the skin impinge on the solar cells provide irregular voltage with temperature or irradiance conditions. Unregulated DC voltage obtained by the PV array implanted beneath the skin can be used as input to the converter. In the present work, the DC-DC boost converter model has been developed to upgrade voltage to stable level from unregulated voltage of solar cell. The results of converter (i.e., output voltage) show stable performance for various input voltages. It is thus capable of regulating the output voltage to above 4 volts from as low as 1 volt input voltage which is adequate to charge Lithium-ion battery used for implantable cardiac pacemakers.