Patent 6979315 was granted and assigned to Medtronic on December, 2005 by the United States Patent and Trademark Office.
An implantable drug delivery device is provided with a passive flow control device is provided in the form of a valve which may assume two flow states. Flow control is achieved by duty cycling the valve using a control module which generates appropriate signals in response to an input telemetry signal corresponding to a desired flow rate. In another embodiment, a passively controlled bolus delivery device is provided to deliver a bolus of drug in addition to normal dosage.