Fluid flow measurement device

• US 6,813,964 B1
• Filed: 05/21/2003
• Issued: 11/09/2004
• Est. Priority Date: 05/21/2003
• Status: Active Grant

• Current Assignee: ICU Medical Incorporated
• Original Assignee: Hospira Incorporated (Pfizer Inc.)
• Inventors: Christianson, Harlow B., Sperinde, John M., Cho, Steve T., Clark, Gene E.
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): Mack, Corey D.
• Application Number:
  US10/442,575
• Publication Number:
  US 20040231432A1
• Time in Patent Office: 538 Days
• Field of Search: 738/61, 738/610.8, 738/614.2, 738/615.2, 738/616.3
• US Class Current: 73/861.52
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/383 with electrical or electro-mechanical indication
• CPC Class Codes: G01F 1/40 Details of construction of the flow constriction devices

Abstract

The invention is directed to a device for obtaining flow rate measurements including a sensor assembly and a housing. The sensor assembly includes a body defining a first fluid flow passage having an inlet, an outlet, a flow restricting element in the first fluid flow passage between the inlet and the outlet, an upstream fluid pressure sensor, a downstream fluid pressure sensor, an upstream signal contact connected to the upstream fluid pressure sensor, and a downstream signal contact connected to the downstream fluid pressure sensor. The housing has an upstream portion defining an upstream port, a downstream portion defining a downstream port, and a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact. The housing can also define a second fluid flow passage in parallel with the first fluid flow passage. The device can be disposable.

Claims

1. A flow sensor device to obtain flow characteristics of a fluid flow system, the device comprising:

a sensor assembly including;

a body defining a first fluid flow passage having an inlet and an outlet,

a flow restricting element located along the first fluid flow passage between the inlet and the outlet,

an upstream fluid pressure sensor to sense an upstream fluid pressure at an upstream location in the first fluid flow passage between the inlet and the flow restricting element,

a downstream fluid pressure sensor to sense a downstream fluid pressure at a downstream location in the first fluid flow passage between the flow restricting element and the outlet,

an upstream signal contact connected to the upstream fluid pressure sensor, and

a downstream signal contact connected to the downstream fluid pressure sensor; and

a housing including an upstream portion and a downstream portion, the upstream portion defining an upstream port in fluid communication with the inlet of the sensor assembly, the downstream portion defining a downstream port in fluid communication with the outlet of the sensor assembly, the housing further defining a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact.

2. The device of claim 1, wherein the housing has at least one registration surface configured to ensure proper registration of the device with a fluid flow system.

3. The device of claim 2, wherein the registration surface ensures the upstream port is aligned with a fluid source of a fluid flow system.

4. The device of claim 2, wherein the registration surface includes a surface configuration on the upstream portion different from a surface configuration on the downstream portion.

5. The device of claim 2, wherein the registration surface includes at least one planar surface.

6. The device of claim 2, wherein the registration surface includes a detent.

7. The device of claim 1, wherein the housing defines a cavity of predetermined shape, the sensor assembly having a shape corresponding to the predetermined shape of the cavity.

8. The device of claim 7, wherein the cavity is defined by at least one surface, the surface including at least one recess to receive a material to hold the sensor assembly within the cavity.

9. The device of claim 8, further comprising a cap positioned in the cavity proximate to the sensor assembly.

10. The device of claim 1, wherein the housing has a connector proximate to at least one of the upstream port and the downstream port.

11. The device of claim 1, wherein the housing defines a second fluid flow passage therethrough.

12. The device of claim 11, wherein the second fluid flow passage is arranged for fluid communication in parallel with the first fluid flow passage between the upstream port and the downstream port.

13. The device of claim 11, further comprising a valve for selective flow through the second fluid flow passage.

14. The device of claim 13, wherein the valve includes at least a portion of the second fluid flow passage, the valve defined by a compressible wall member.

15. The device of claim 14, wherein the compressible wall member is formed from an elastomeric material.

16. The device of claim 14, wherein the second fluid flow passage has a first transverse dimension and a second transverse dimension perpendicular to the first transverse dimension, the first dimension being different than the second dimension.

17. A fluid sensor system, comprising:

a probe to receive signals representative of a fluid flow characteristic;

a processor to process signals from the probe into flow characteristic data; and

a device to obtain flow characteristic measurements of a fluid flow system, the device including;

a sensor assembly including;

a body defining a first fluid flow passage having an inlet and an outlet,

a flow restricting element located along the first fluid flow passage between the inlet and the outlet,

an upstream fluid pressure sensor to sense an upstream fluid pressure at an upstream location in the first fluid flow passage between the inlet and the flow restricting element,

a downstream fluid pressure sensor to sense a downstream fluid pressure at a downstream location in the first fluid flow passage between the flow restricting element and the outlet,

an upstream signal contact connected to the upstream fluid pressure sensor, and

a downstream signal contact connected to the downstream fluid pressure sensor; and

a housing including an upstream portion and a downstream portion, the upstream portion defining an upstream port in fluid communication with the inlet of the sensor assembly, the downstream portion defining a downstream port in fluid communication with the outlet of the sensor assembly, the housing further defining a probe access port configured to provide access of the probe to at least one of the upstream signal contact and downstream signal contact.

18. The system of claim 17, wherein the probe includes a connector body having a predetermined shape, and further wherein the probe access port has a shape corresponding to the predetermined shape to ensure proper alignment of the probe with the at least one of the upstream signal contact and downstream signal contact.

19. The system of claim 18, wherein the predetermined shape is a wedge configuration.

20. The system of claim 17, wherein the probe includes a plurality of leads, at least a first lead configured for communication with the upstream signal contact when the probe is positioned in the probe access port and at least a second lead configured for communication with the downstream signal contact when the probe is positioned in the probe access port.

21. The system of claim 20, wherein at least one lead of the probe is configured for a wipe type connection.

22. The system of claim 17, further comprising a fluid flow line in communication with a fluid source;

and further wherein the housing has at least one registration surface configured to ensure proper registration of the device with the fluid flow line.

23. The system of claim 22, further comprising a locking mechanism to mate the housing with the fluid flow line, the locking mechanism having an unlocked condition for receipt of the housing, a first locked condition to align the housing with the fluid flow line and a second locked condition to position the probe in the housing.

24. The system of claim 23, wherein the housing defines a second fluid flow passage for third communication in parallel with the first fluid flow passage between the upstream port and the downstream port.

25. The system of claim 24, further comprising a valve for selective flow through the second fluid flow passage, the valve having a first condition to allow flow through the second flow passage and a second condition to prevent flow through the second flow passage, the system further comprising an actuator to change the valve from the first condition to the second condition when the locking mechanism is moved from the first locked condition to the second locked condition.

26. The system of claim 25, wherein the valve includes a compressible wall member, and further wherein the actuator includes a protrusion to compress the compressible wall member.

27. The system of claim 26, wherein the protrusion is a pin.

28. The system of claim 22, wherein the fluid source includes a pump connected to the fluid flow line to selectively pump fluid through the first fluid flow passage;

and further wherein the processor includes means to control the pump in response to signals obtained by the probe from the sensors.

29. A method of obtaining flow characteristics of a fluid flow system, the method comprising the steps of:

providing a device to obtain flow rate measurements, the device comprising;

a sensor assembly including;

a body defining a first fluid flow passage having an inlet and an outlet,

a flow restricting element located along the first fluid flow passage between the inlet and the outlet,

an upstream fluid pressure sensor to sense an upstream fluid pressure at an upstream location in the first fluid flow passage between the inlet and the flow restricting element,

a downstream fluid pressure sensor to sense a downstream fluid pressure at a downstream location in the first fluid flow passage between the flow restricting element and the outlet,

an upstream signal contact connected to the upstream fluid pressure sensor, and

a downstream signal contact connected to the downstream fluid pressure sensor, and

a housing including an upstream portion and a downstream portion, the upstream portion defining an upstream port in fluid communication with the inlet of the sensor assembly, the downstream portion defining a downstream port in fluid communication with the outlet of the sensor assembly, the housing further defining a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact;

directing a fluid flow through the first fluid flow passage;

obtaining a signal corresponding to the fluid pressure in the first fluid flow passage at the locations of the upstream fluid pressure sensor and the downstream fluid pressure sensor; and

determining a flow characteristic based upon the signal.

30. The method of claim 29, wherein the determining step includes determining the pressure difference between the upstream and downstream fluid pressure sensors.

31. The method of claim 30, wherein the determining step further includes calculating flow rate of fluid through the first fluid flow passage based on the pressure difference.

32. The method of claim 29, wherein the determining step includes detecting the presence of air in the first fluid flow passage.

33. The method of claim 32, wherein the step of detecting air in the first fluid flow passage includes identifying convergence and specific waveforms of the signal from the upstream fluid pressure sensor and the signal from the downstream fluid pressure sensor.

34. The method of claim 29, further comprising the steps of:

intermittently pulsing fluid through the first fluid flow passage; and

further wherein the determining step includes identifying an amount of fluid delivered with each pulse, the determining step including detecting the fluid pressure in the first fluid flow passage.

35. The method of claim 32, wherein the housing provided by the housing step includes:

a second fluid flow passage, and

a valve for selective flow through the second fluid flow passage, the valve having a first condition to allow flow through the second flow passage and a second condition to prevent flow through the second flow passage; and

the method further comprising the step of opening the valve to increase flow through the housing.

36. The method of claim 29, wherein the determining step includes detecting the presence of an occlusion in the fluid flow system.

37. The method of claim 36, wherein the step of detecting an occlusion in the fluid flow system further includes detecting the location of an occlusion.

38. The method of claim 37, wherein the step of detecting an occlusion includes identifying specific waveforms of the signal from the upstream fluid pressure sensor and the signal from the downstream fluid pressure.

39. The method of claim 29, wherein the determining step includes detecting the presence of air in the first fluid flow passage and calculating the volume of air by determining amount of time air is present in the first fluid flow passage.