Patent ID: 8858517

Claim:
A method of operating a battery-powered medical device having a pump providing a vacuum to an associated negative pressure wound therapy apparatus, said medical device having a microprocessor and operative components coupled to said microprocessor to minimize power consumption from the battery, comprising the steps of: providing said microprocessor with a modulation circuit, said modulation circuit powering the operation of said pump only when a pressure sensor associated with the vacuum applied to said negative pressure wound therapy apparatus indicates that the negative pressure of the vacuum is at a threshold level; operating said pump and a selected first portion of said operative components intermittently through said modulation circuit as required by said microprocessor for operation of said medical device and operating a selected second portion of said operative components in response to the operation of said first portion of said operative components, one of said second portion of said operative components including a tilt sensor associated with said pump to provide a signal to said microprocessor when said pump is in a non-vertical position, one of said first portion of said operative components being a fill sensor providing a signal to said microprocessor when a canister associated with said pump is filled with fluid from the operation of said negative pressure wound therapy apparatus; intermittently operating said fill sensor through said modulation circuit to check fluid levels within said canister; and activating said tilt sensor only when the microprocessor receives a signal from said fill sensor indicating activation thereof by fluids within said canister.