Patent ID: 11964130
Assignee: MEDTRONIC, INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 12:
13. A method of producing an implantable medical device comprising a volume measurement system, the method comprising:
providing an implantable medical device comprising a housing that defines a propellant chamber, and a drug reservoir positioned within the propellant chamber;
installing a volume measurement system in the implantable medical device, the volume measurement system comprising a temperature sensor configured to measure a temperature of a propellant gas within the propellant chamber and a pressure sensor configured to measure a pressure of the propellant gas within the propellant chamber;
charging the propellant chamber with a positive gauge pressure of the propellant gas; and
calibrating the volume measurement system so that the volume measurement system is configured to measure the pressure and the temperature of the propellant gas to provide current volume information of the therapeutic fluid in the drug reservoir, and without requiring direct contact of the therapeutic fluid with the temperature sensor.