FLUID PROPERTY MEASUREMENT DEVICES, METHODS, AND SYSTEMS

• US 20150204733A1
• Filed: 07/25/2013
• Published: 07/23/2015
• Est. Priority Date: 07/25/2012
• Status: Active Grant

• Current Assignee: Nxstage Medical Incorporated (Fresenius Medical Care AG)
• Original Assignee: Nxstage Medical Incorporated (Fresenius Medical Care AG)
• Inventors: Newell, Scott W., Kogan, Yakov
• Granted Patent: US 9,846,085 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01K 1/14 Supports; Fastening devices; Arrangements for mounting thermometers in particular locations
• CPC Class Codes: G01K 13/026 of moving liquids
• CPC Class Codes: G01K 7/16 using resistive elements resistive elements per se H01C, H01L

Abstract

High accuracy temperature measurement devices, methods, and systems for measuring the temperature of medical fluids are described. In embodiments, the devices have the features that they are compatible with the measurement of temperatures in a sealed fluid circuit, thereby promoting compatibility with sterile disposable circuits. Also described are combinations of temperature sensors and conductivity measurement for precise determination of the concentration of ions in a medicament.

Claims

1. A vessel/channel with a temperature detecting device, comprising:

a first temperature sensor attached to or placed against a wail of a vessel/channel configured for carrying or containing a fluid;

a second temperature sensor separated from the first temperature sensor by an insulating body having a thermal resistance similar to the vessel/channel wall;

a temperature regulating device in thermal contact with the second temperature sensor and configured to receive first and second temperature indication signals, respectively, from the first and second temperature sensors;

the temperature regulating device being further configured to minimize a difference in temperatures indicated by said first and second temperature signals by regulating a rate of flow of heat between the first and second temperature sensors.

2. The device of claim 1, wherein the temperature regulating device includes a thermoelectric heat pump or a dissipative heater.

4. The device of claim 1, wherein at least one of the second temperature sensor and the temperature regulating device has a surface that extends beyond a surface of the first temperature sensor.

5. The device of claim 1, wherein the insulating body fills an empty space between the second temperature sensor and the fluid vessel/channel wall.

6. The device of claim 1, wherein the vessel/channel is a bag or flexible membrane configured to contain a medicament or a biological fluid or the vessel/channel is a fluid circuit configured to convey a medicament or a biological fluid.

3. (canceled)

7-16. -16. (canceled)

17. A temperature detecting device, comprising:

a first temperature sensor attached to a flat member that is adapted to be placed against a wall of a vessel/channel configured for carrying or containing a fluid;

a second temperature sensor separated from the first temperature sensor by an insulating gap;

a temperature regulating device in thermal contact with the second temperature sensor; and

a controller configured to receive first and second temperature indication signals, respectively, from the first and second temperature sensors and to regulate said temperature regulating device responsively to the temperature indication signals therefrom;

the controller being configured to regulate a heat flux rate through said flat member responsively to said temperature indication signals from said first and second temperature sensors such that a temperature of at least said first temperature sensor indicates a temperature of a fluid on an a side of said wall opposite said first temperature sensor.

18. The device of claim 17, wherein the temperature regulating device includes a thermoelectric heat pump.

19. The device of claim 17, wherein the temperature regulating device includes a dissipative heater.

20. The device of claim 17, wherein at least one of the second temperature sensor and or the temperature regulating device has a surface that extends beyond a surface of the first temperature sensor.

21. The device of any of claim 17, wherein the insulating gap includes an insulating body between the first and second temperature sensors.

22. The device of claim 17, wherein the vessel/channel is a bag or flexible membrane configured to contain a medicament or a biological fluid, or the vessel/channel is a fluid circuit configured to convey a medicament or a biological fluid.

23. (canceled)

24. A temperature detecting device, comprising:

a first temperature sensor attached to a first flat member that is adapted to be placed against a wall of a vessel/channel configured for carrying or containing a fluid;

a second temperature sensor attached to a second flat member separated from the first temperature sensor by a spacer;

a temperature regulating device in thermal contact with the second flat member opposite the second temperature sensor; and

a controller configured to receive first and second temperature indication signals, respectively, from the first and second temperature sensors and to regulate said temperature regulating device responsively to the temperature indication signals therefrom;

the controller being configured to regulate a heat flux rate through said first flat member or said second flat member responsively to said temperature indication signals from said first and second temperature sensors such that temperature of at least said first temperature sensor indicates a temperature of a fluid on an a side of said wall opposite said first temperature sensor.

25. The device of claim 24, wherein the temperature regulating device includes a thermoelectric heat pump or a dissipative heater.

26. The device of claim 24, wherein the spacer and first and second flat members are adhesively or thermally bonded together.

30. The device of claim 24, further comprising a heat transfer member of Aluminum Nitride, or Beryllium Oxide, the heat transfer member being disposed adjacent said second temperature sensor and adapted for maintaining a uniform temperature across the temperature regulating device.

31. The device of claim 24, wherein the first and second flat members carry conductors that make electrical contact between the temperature sensors and the controller.

32. The device of claim 24, further comprising a heat transfer member of metal or ceramic adjacent said second temperature sensor and adapted for maintaining a uniform temperature across the temperature regulating device.

33. The device of claim 24, further comprising thermally conductive attachment portions on one, both of, or between the spacer and the first and second flat members, adapted to distribute heat in directions forming a right angle to the line between the first and second temperature sensors.

34. The device of claim 24, wherein the spacer has an opening in the center thereof such that an air gap is defined between the first and second temperature sensors.

37. The device of claim 31, wherein the first and second flat members have electrical leads arranged in a manner such that each electrical lead follows a indirect path from an end portion of one of the first and second flat members, whereby thermal conduction from the first and second temperature sensors in a radial direction is minimized.

38. The device of claim 37, wherein the indirect paths are such that the electrical leads circumscribe, at least partly, the first and second temperature sensors.

39. The device of claim 37, wherein the indirect paths are such that the electrical leads are serpentine.

40. The device of claim 37, wherein the indirect paths are such that the electrical leads curve around the first and second temperature sensors.

45. The device of claim 37, wherein each said end portion is substantially round and major portions of the electrical leads follow a respective path that is substantially tangential to a circumference of one of the end portions.

46. The device of claim 45, wherein the indirect paths are such that the major portions of the electrical leads double back on themselves.

27-29. -29. (canceled)

35-36. -36. (canceled)

41-44. -44. (canceled)

47-122. -122. (canceled)