While powering electronics with blood pressure may seem impractical, the numbers are actually quite surprising. Assuming an average blood pressure of 100 mm of Hg (normal desired blood pressure is 120/80 above atmospheric pressure), a resting heart rate of 60 beats per minute, and a heart stroke volume of 70 ml passing through the aorta per beat [Braunwald (ed.), 1980], then the power generated is
While this energy rate can easily double when running, harnessing this power is difficult. Adding a turbine to the system would increase the load on the heart, perhaps dangerously so. However, even if 2% of this power is harnessed, low power microprocessors and sensors could run. Thus, self-powering medical sensors and prostheses could be created.