Cardiology fellow here. The more you have to pace the shorter the battery lasts? Struggling to see what the novelty is here.

> Longevity can be calculated based upon a simple concept entitled the “power consumption index” (PCI = t x I/C, where t is a constant of 1 hour, I is the current required by the device and C, its battery capacity).

So basically current draw over battery capacity? Or just amps / amp-hours, then * 1 hour to get rid of the unit. Surprised that's not already a standard metric.