Patent ID: 7122026

Claim:
An implantable infusion device with energy efficient motor drive, comprising: a housing; a power source carried in the housing; a therapeutic substance reservoir carried in the housing, the therapeutic substance reservoir configured for containing a therapeutic substance and being refilled with the therapeutic substance while implanted; a therapeutic substance pump carried in the housing, the therapeutic substance pump fluidly coupled to the therapeutic substance reservoir, and electrically coupled to the power source; a motor coupled to the power source and coupled to the therapeutic substance pump; electronics carried in the housing, the electronics coupled to the motor and the power source, the electronics including, a processor, memory coupled to the processor, an infusion program residing in memory, the infusion program capable of being modified once the therapeutic substance infusion device is implanted; transceiver circuitry coupled to the processor for externally receiving and transmitting therapeutic substance infusion device information; a power source measurement circuit to measure power source voltage; and, a motor drive circuit configured to generate a varying duty cycle of drive pulses in a substantially fixed drive interval, the varying duty cycle of drive pulses increasing as the power source voltage measured by the power source measurement circuit to decreases to optimize and reduce motor energy consumption.