Patent ID: 9550034
Date: 2017-01-24
CPC Classifications: A61M,B05B,G01F,G01H,G10K

Claim:
1. A method for metering fluid output comprising: providing a printed circuit board having a first microphone, a second microphone and an acoustic source enclosing the printed circuit board with a housing in such a way as to define a first volume of an acoustic system, the acoustic system having a resonant frequency; mounting a diaphragm covered fluid region against the housing to define an air region between the housing and fluid region, the air region being a part of the acoustic system; fluidically coupling an output valve to the fluid region; coupling the first microphone to the first volume; coupling the acoustic source to the first volume; coupling the second microphone to the air region; exciting the acoustic system at a pre-determined frequency with the acoustic source; receiving a first signal from the first microphone associated with an acoustic response of the first volume to excitement at a pre-determined frequency; receiving a second signal from the second microphone associated with an acoustic response of the air region to excitement at a pre-determined frequency; determining a volume of the air region associated with the first signal and the second signal; and controlling the output valve to meter fluid from the fluid region associated with the volume of the air region.