Device to meter fluid

Patent metadata

Field	Value
Publication number	US-9610414-B2
Application number	US-201514812024-A
Country	US
Kind code	B2
Filing date	Jul 29, 2015
Priority date	Sep 25, 2003
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

An apparatus for metering the delivery of a fluid. The apparatus has a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus may also include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region.

First claim

What is claimed is:

1. A device to meter fluid comprising:
a fluid reservoir;
an acoustic volume sensor including:
a housing containing a first volume and a second volume, the second volume including an air region, and a fluid region, and
a printed circuit board disposed within the housing, the printed circuit board defining the first volume within the housing and the printed circuit board including:
an acoustic source,
a first microphone acoustically coupled to the first volume, and
a second microphone acoustically coupled to the air region;

an input valve in fluid communication with the fluid reservoir and configured to allow fluid to enter the fluid region; and
a processor in communication with the acoustic volume sensor and configured to meter fluid output from the device.

2. A device to meter fluid according to claim 1 further comprising an output valve, the output valve in fluid communication with the fluid region and the output valve being controlled by the processor.

3. A device to meter fluid according to claim 2 wherein the processor determines the volume of the air region associated with signals from the first microphone and second microphone.

4. A device to meter fluid according to claim 3 wherein the processor controls the output valve based on the determined volume of air region.

5. A device to meter fluid according to claim 1 further comprising a hole in the printed circuit board to equalize pressure between the first volume and the air region.

6. A device to meter fluid according to claim 1 wherein the printed circuit board comprises a temperature sensor, the temperature sensor in communication with the processor.

7. A device to meter fluid according to claim 1 , wherein the fluid in the fluid reservoir and the fluid region is a drug.

8. A device to control fluid output comprising:
a fluid reservoir;
an output valve;
an acoustic volume sensor including:
a housing containing a first volume and a second volume, the second volume including an air region, and a fluid region, and
a printed circuit board disposed within the housing, the printed circuit board defining the first volume within the housing and the printed circuit board including:
an acoustic source,
a first microphone acoustically coupled to the first volume, and
a second microphone acoustically coupled to the air region;

wherein the fluid region is in fluid communication with the fluid reservoir and the fluid region is in fluid communication with the output valve; and
a processor in electrical communication with the acoustic volume sensor, the processor coupled to the output valve, the processor configured to control the output valve to allow a selected volume of fluid to exit from the fluid region.

9. A device to control fluid output according to claim 8 wherein the first volume and air region form at least part of an acoustic system.

10. A device to control fluid output according to claim 9 wherein the processor comprises:
controlling the acoustic source to generate an acoustic excitement in the acoustic system,
receiving a first signal from the first microphone in response to the acoustic excitement, and
receiving a second signal from the second microphone in response to the acoustic excitement.

11. A device to control fluid output according to claim 10 wherein the processor determines the volume of the air region associated with the first signal and the second signal.

12. A device to control fluid output according to claim 11 wherein the processor controls the output valve based on the determined volume of air region.

13. A device to control fluid output according to claim 10 wherein the processor determines the resonant frequency of the acoustic system associated with the first signal and second signal.

14. A device to meter fluid according to claim 8 further comprising a hole in the printed circuit board to equalize pressure between the first volume and the air region.

15. A device to meter fluid according to claim 8 wherein the printed circuit board comprises a temperature sensor, the temperature sensor in communication with the processor.

16. A medical device to control fluid comprising:
a disposable drug cassette including a drug reservoir and a fluid region, the fluid region in fluid communication with the drug reservoir;
an acoustic volume sensor including:
a housing containing a first volume and defining a variable volume chamber, the variable volume chamber being adjacent to the fluid region, and
a printed circuit board disposed within the housing, the printed circuit board defining the first volume within the housing and the printed circuit board including:
an acoustic source,
a first microphone acoustically coupled to the first volume, and
a second microphone acoustically coupled to the variable volume chamber;

an output valve in fluid communication with the fluid region; and
a processor in electrical communication with the acoustic volume sensor, the processor coupled to the output valve, the processor configured to control the output valve to allow a selected volume of fluid to exit from the fluid region.

17. A medical device to control fluid according to claim 16 wherein the disposable drug cassette mounts to the housing, the disposable drug cassette comprises a diaphragm, the fluid region further defines the variable volume chamber and the fluid region is separated from the variable volume chamber by the diaphragm.

18. A medical device to control fluid according to claim 17 wherein the volume of the variable volume chamber plus the volume of the fluid region is constant.

19. A medical device to control fluid according to claim 16 wherein the first volume and variable volume chamber form at least part of an acoustic system.

20. A medical device to control fluid according to claim 19 wherein the processor comprises:
controlling the acoustic source to generate an acoustic excitement in the acoustic system,
receiving a first signal from the first microphone in response to the acoustic excitement, and
receiving a second signal from the second microphone in response to the acoustic excitement.

21. A medical device to control fluid according to claim 20 wherein the processor determines the volume of the variable volume chamber associated with first signal and the second signal.

22. A medical device to control fluid according to claim 21 wherein the processor controls the output valve based on the determined volume of variable volume chamber.

23. A medical device to control fluid according to claim 20 wherein the printed circuit board comprises a temperature sensor and the temperature sensor provides a temperature signal to the processor.

24. A medical device to control fluid according to claim 23 wherein the processor comprises:
determining the resonant frequency of the acoustic system associated with the first signal and second signal, and
determining the volume of the variable volume chamber associated with the resonant frequency of the acoustic system and the temperature signal.

25. A medical device to control fluid according to claim 24 wherein the processor determines the resonant frequency of the acoustic system further associated an underdamped second-order model of the acoustic system.

26. A medical device to control fluid according to claim 16 further comprising a hole in the printed circuit board to equalize pressur

Assignees

• Deka Products Lp

Inventors

• Beavis Russell H
• Gray Larry B
• Kane Derek G

Classifications

• G01F17/00

  Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies (measuring linear dimensions to determine volume G01B) · CPC title

• G01F1/007

  by measuring the level variations of storage tanks relative to the time · CPC title

• G01H3/00

  Measuring {characteristics of} vibrations by using a detector in a fluid (G01H7/00, G01H9/00, G01H11/00 take precedence) · CPC title

• G10K9/04

  by compressed gases, e.g. compressed air · CPC title

• B05B12/006

  Pressure or flow rate sensors · CPC title