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

Claim 0:
1. An implantable medical device comprising:

a housing defining a propellant chamber therein;
a drug reservoir located within the propellant chamber of the housing configured to receive a therapeutic fluid therein;
a propellant gas within the propellant chamber; and

a volume measurement system comprising:
a temperature sensor configured to measure a temperature of the propellant gas within the propellant chamber;
a pressure sensor configured to measure a pressure of the propellant gas within the propellant chamber, wherein 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.