Patent ID: 8287514

Claim:
A method of administering medicinal fluid to a patient, the method comprising: supplying a pattern of multiple voltage pulses from a rechargeable energy source to a drive system of a pump device to activate the drive system during a predetermined actuation time and dispense medicinal fluid from the pump device, a controller device changing a width or frequency of the multiple pulses in the pattern to apply during the predetermined actuation time in response to detecting that the drive system completed a medicine dispensing operation in less time or more time than the predetermined actuation time; charging the rechargeable energy source with energy from a replaceable battery to maintain the rechargeable energy source at a charge level greater than a threshold charge level when the replaceable battery is in a non-depleted state; adjusting the pattern of multiple voltage pulses to apply during the predetermined actuation time based on a voltage of the rechargeable energy source; and outputting a user alert indicative of a remaining power supply based at least partially on the threshold charge level when the replaceable battery is in a depleted state or disconnected from electrical communication with the rechargeable energy source.