System, method, and apparatus for monitoring, regulating, or controlling fluid flow

• US 10,228,683 B2
• Filed: 02/29/2016
• Issued: 03/12/2019
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Peret, Bob David, Yoo, Brian H., Kane, Derek G., Kamen, Dean, Murphy, Colin H., Kerwin, John M.
• Primary Examiner(s): Sarkar, Asok K
• Application Number:
  US15/055,941
• Publication Number:
  US 20160179086A1
• Time in Patent Office: 1,107 Days
• Field of Search: None
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/2607 Infusion controller
• CPC Class Codes: G05B 2219/41303 Flow rate valve controls speed
• CPC Class Codes: G05D 7/0617 specially adapted for fluid materials
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: G05D 7/0676 by action on flow sources G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/13 Edge detection
• CPC Class Codes: G06T 7/174 involving the use of two or more images
• CPC Class Codes: G06V 10/751 Comparing pixel values or logical combinations thereof, or feature values having positional relevance, e.g. template matching

Abstract

A flow meter, and related system and method are provided. The flow meter includes a coupler, a support member, an image sensor, a valve, and one or more processors. The coupler is adapted to couple to a drip chamber. The support member is operatively coupled to the coupler. The image sensor has a field of view and is operatively coupled to the support member. The image sensor is positioned to view the drip chamber within the field of view. The one or more processors are operatively coupled to the image sensor to receive image data therefrom and to the actuator to actuate the valve. The one or more processors are configured to estimate a flow of fluid through the drip chamber and to actuate the valve to control the flow of fluid through the drip chamber to achieve a target flow rate.

Claims

1. A flow meter, comprising:

an image sensor having a field of view, wherein the image sensor is positioned to view a drip chamber within the field of view;

a valve comprising;

a rigid chamber;

a flexible tube section disposed within the rigid chamber, the flexible tube section in fluid communication with the drip chamber;

a pump fluidly coupled to the rigid chamber and configured to pump fluid into and out of the rigid chamber to thereby actuate the valve; and

an actuator coupled to the pump and configured to actuate the pump; and

at least one processor in communication with the image sensor to receive image data therefrom and with the actuator to actuate the valve, wherein the at least one processor is configured to estimate a flow of fluid through the drip chamber and to actuate the valve to control the flow of fluid through the drip chamber to achieve a target flow rate,

wherein the at least one processor compares an image of the image data to a reference image to estimate at least one parameter of liquid within the drip chamber.

2. The flow meter according to claim 1, wherein the at least one processor determines an existence of a free flow condition using a distortion of a background pattern caused by a liquid as indicated by the image data.

3. The flow meter according to claim 2, wherein the background pattern is an array of lines having at least one angle relative to an opening of the drip chamber when viewed from the image sensor using the image data.

4. The flow meter according to claim 3, wherein the at least one processor determines the free flow condition exists when the liquid causes the array of lines to change angles by the distortion caused by the liquid when in the free flow condition as viewed within the field of view of the image sensor.

5. The flow meter according to claim 1, further comprising a non-transitory processor-readable memory in operative communication with the at least one processor, wherein the non-transitory processor-readable memory includes an operative set of processor executable instructions configured for execution by the at least one processor, wherein the operative set of processor executable instructions, when executed by the at least one processor, controls the operation of the at least one processor.

6. The flow meter according to claim 1, wherein the at least one processor updates the reference image by multiplying each pixel of the reference image by a first constant and adding a corresponding pixel of the image multiplied by a second constant.

7. The flow meter according to claim 1, wherein the at least one processor updates the reference image by multiplying each pixel of the reference image by a first constant and adding a corresponding pixel of the image multiplied by a second constant.

8. The flow meter according to claim 1, further comprising a transceiver, wherein the at least one processor is configured to communicate with a monitoring client through the transceiver to communicate the estimated flow of fluid through the drip chamber.

9. The flow meter according to claim 1, wherein the at least one parameter of liquid is the estimated flow of fluid through the drip chamber.

10. A system comprising:

a flow meter, comprising;

an image sensor having a field of view, wherein the image sensor is positioned to view a drip chamber within the field of view;

a valve comprising a rigid chamber, a flexible tube section disposed within the rigid chamber wherein the flexible tube section is in fluid communication with the drip chamber, a pump operatively coupled to the rigid chamber and configured to pump fluid into and out of the rigid chamber to thereby actuate the valve, and an actuator coupled to the pump and configured to actuate the pump; and

at least one processor in communication with the image sensor to receive image data therefrom and with the actuator to actuate the valve, wherein the at least one processor is configured to estimate a flow of fluid through the drip chamber and to actuate the valve to control the flow of fluid through the drip chamber to achieve a target flow rate, wherein the at least one processor compares an image of the image data to a reference image to estimate at least one parameter of liquid within the drip chamber; and

a monitoring client in operative communication with the flow meter to receive the estimated flow of fluid through the drip chamber.

11. A method of controlling a flow meter, the method comprising:

capturing an image of a drip chamber using an image sensor;

estimating a flow of fluid, using a processor, through the drip chamber using the image sensor;

actuating a valve, using the processor, to cause the flow of fluid to reach a target flow rate, the valve comprising a rigid chamber, a flexible tube section disposed within the rigid chamber wherein the flexible tube section is in fluid communication with the drip chamber, a pump operatively coupled to the rigid chamber and configured to pump fluid into and out of the rigid chamber to thereby actuate the valve;

comparing, using the processor, the image of the drip chamber to a reference image to estimate at least one parameter of liquid within the drip chamber; and

an actuator coupled to the pump and configured to actuate the pump.

12. The method according to claim 11, further comprising the act of communicating the estimated flow of fluid to a monitoring client.

13. A flow meter, comprising:

an image sensor having a field of view, wherein the image sensor is positioned to view a drip chamber within the field of view;

a valve comprising;

a rigid chamber;

a flexible tube section disposed within the rigid chamber and in fluid communication with the drip chamber;

a pump operatively coupled to the rigid chamber and configured to pump fluid into and out of the rigid chamber to thereby actuate the valve; and

an actuator coupled to the pump and configured to actuate the pump; and

at least one processor in communication with the image sensor to receive image data therefrom and with the actuator to actuate the valve, wherein the at least one processor is configured to estimate a flow of fluid through the drip chamber and to actuate the valve to control the flow of fluid through the drip chamber to achieve a target flow rate,

wherein the at least one processor determines an existence of a free flow condition using a distortion of a background pattern caused by a liquid as indicated by the image data.

14. The flow meter according to claim 13, wherein the background pattern is an array of lines having at least one angle relative to an opening of the drip chamber when viewed from the image sensor using the image data.

15. The flow meter according to claim 14, wherein the at least one processor determines the free flow condition exists when the liquid causes the array of lines to change angles by the distortion caused by the liquid when in the free flow condition as viewed within the field of view of the image sensor.

16. The flow meter according to claim 13, wherein the target flow rate is a drop growth rate.

17. The flow meter according to claim 16, wherein the at least one processor is further configured to actuate the valve to control the drop growth rate to thereby achieve the target flow rate.

18. A flow meter, comprising:

an image sensor having a field of view, wherein the image sensor is positioned to view a drip chamber within the field of view;

a valve comprising;

a rigid chamber;

a flexible tube section disposed within the rigid chamber, the flexible tube section in fluid communication with the drip chamber; and

an actuator configured to actuate the valve; and

at least one processor in communication with the image sensor to receive image data therefrom and with the actuator to actuate the valve, wherein the at least one processor is configured to estimate a flow of fluid through the drip chamber and to actuate the valve to control the flow of fluid through the drip chamber to achieve a target flow rate,

wherein the at least one processor compares an image of the image data to a reference image to estimate at least one parameter of a liquid within the drip chamber.

19. The flow meter according to claim 18, wherein the at least one processor determines an existence of a free flow condition using a distortion of a background pattern caused by the liquid as indicated by the image data.

20. A flow meter, comprising:

an image sensor having a field of view, wherein the image sensor is positioned to view a drip chamber within the field of view;

a valve configured to control a flow of fluid through the drip chamber;

an actuator configured to actuate the valve to thereby control the flow of fluid through the drip chamber; and

at least one processor in communication with the image sensor to receive image data therefrom and with the actuator to actuate the valve, wherein the at least one processor is configured to estimate the flow of fluid through the drip chamber and to actuate the valve to control the flow of fluid through the drip chamber to achieve a target flow rate,

wherein the at least one processor compares an image of the image data to a reference image to estimate at least one parameter of liquid within the drip chamber and to thereby actuate the valve using the actuator in response to the at least one parameter of a liquid to achieve the target flow rate.

21. The flow meter according to claim 20, wherein the at least one processor determines an existence of a free flow condition using a distortion of a background pattern caused by the liquid as indicated by the image data.

22. The flow meter according to claim 21, wherein the at least one processor determines the free flow condition exists when the liquid causes an array of lines of the background pattern to change angles by the distortion caused by the liquid when in the free flow condition as viewed within the field of view of the image sensor.

23. The flow meter according to claim 20, wherein the at least one processor updates the reference image by multiplying each pixel of the reference image by a first constant and adding a corresponding pixel of the image multiplied by a second constant.

24. The flow meter according to claim 20, wherein the at least one processor is further configured to identify a plurality of pixels of interest within the image.

25. The flow meter according to claim 24, wherein the at least one processor is further configured to determine a subset of pixels within the plurality of pixels of interest.

26. The flow meter according to claim 25, wherein each pixel of the plurality of pixels of interest is determined to be within the subset of pixels when there is a path to a baseline corresponding to the drip chamber.

27. The flow meter according to claim 26, wherein the baseline is a predetermined set of pixels within the image sensor.

28. The flow meter according to claim 25, wherein the at least one processor is further configured to perform a rotation operation on the subset of pixels.

29. The flow meter according to claim 28, wherein the at least one processor is further configured to estimate a volume of a drop within the drip chamber by counting a number of pixels within the rotated subset of pixels.

30. The flow meter according to claim 24, wherein the plurality of pixels of interest are identified by comparing the image to the reference image.

31. The flow meter according to claim 20, wherein the at least one processor is further configured to initialize the reference image.

32. The flow meter according to claim 20, wherein the at least one processor is further configured to update the reference image using the image captured by the image sensor.

33. The flow meter according to claim 32, wherein the reference image is updated in accordance with:

P_{background,i,j}=P_{background,i,j}(1−

α

_background)+α

_backgroundP_input,i,j.

34. The flow meter as in claim 20, wherein the at least one processor is further configured to update an array of variances using the image captured by the image sensor.

35. The flow meter according to claim 34, wherein the array of variances is) updated in accordance with:

σ

_temp²=(P_{background,i,j}−

P_input,i,j)²

σ

_{background,i,j}²=σ

_{background,i,j}²(1−

β

_background)+β

_backgroundσ

_temp².

36. The flow meter according to claim 20, wherein the at least one processor is further configured to update an array of integers in accordance with the image captured by the image sensor.

37. The flow meter according to claim 36, wherein each integer of the array of integers corresponds to a number of updates of a pixel of the reference image.

38. The flow meter according to claim 37, wherein the comparison of the image to the reference image only compares pixels within the image to pixels within the reference image if a respective integer of the array of integers indicates a respective pixel within the reference image has been updated at least a predetermined number of times.

39. The flow meter according to claim 20, wherein the at least one processor is further configured to:

identify a drop in the image and a predetermined band near an edge of the drop; and

initialize the reference image by setting each pixel of the reference image to the image unless it is within the identified drop or the predetermined band near the edge of the drop.

40. The flow meter according to claim 39, wherein the at least one processor is further configured to set a pixel of the reference image to a predetermined value if a corresponding pixel of the image is within the identified drop or the predetermined band near the edge of the drop.

41. The flow meter according to claim 40, wherein the corresponding pixel of the image has a location corresponding to a location of the pixel of the reference image.

42. The flow meter according to claim 20, wherein a baseline corresponds to an opening of the drip chamber.

43. The flow meter according to claim 42, wherein the at least one processor is further configured to determine whether each of a plurality of pixels of interest is within a subset of pixels if a respective pixel of the plurality of pixels of interest has a contiguous path back to the baseline.

44. The flow meter according to claim 20, further comprising a transceiver, wherein the at least one processor is configured to communicate with a monitoring client through the transceiver to communicate the estimated flow of fluid through the drip chamber.