Fluid temperature sensor

• US 4,476,877 A
• Filed: 08/16/1982
• Issued: 10/16/1984
• Est. Priority Date: 08/16/1982
• Status: Expired due to Term

• Current Assignee: Becton Dickinson Critical Care Systems Pte Ltd. (Becton, Dickinson & Co)
• Original Assignee: Gould, Inc. (Transdigm Group Incorporated)
• Inventors: Barker, John M.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Sykes, Angela D.
• Application Number:
  US06/408,080
• Time in Patent Office: 792 Days
• Field of Search: 128/691-692, 128/736, 128/713, 73/204, 604/52-53
• US Class Current: 600/549
• CPC Class Codes: A61B 5/028 by thermo-dilution

Abstract

A temperature sensing device for use in a fluid flow system for accurately sensing the temperature of fluid delivered through a lumen of a housing of the device. A temperature sensor element is isolated from the fluid in the lumen by its reception in an enclosure extending through a portion of the wall of the housing into the lumen. The temperature sensor is provided in association with a connector including suitable leads for transferring the electrically generated signal from the sensor to a cable connected to a computer for use in making thermodilution determinations. By permitting the expensive temperature sensor structure to be reusable without the need for repeated sterilization thereof while permitting the flow-through housing to be disposable, long, troublefree life at low cost is provided.

Claims

1. For use in a flow system such as a cardiovascular flow measuring system wherein a cold injectate fluid is delivered in a known amount from a supply through a catheter into a patient'"'"'s blood vessel and the resultant change in the temperature of the patient'"'"'s blood is sensed to determine the circulatory blood flow rate, an improved injectate fluid temperature sensor comprising:

a disposable housing defining a through lumen for conducting injectate fluid therethrough;

a disposable thermally conductive enclosure hermetically sealingly joined to the housing and projecting transversely into said lumen to be in heat transfer association with injectate fluid conducted through said lumen; and

a reusable temperature sensor removably installed in said enclosure, said sensor providing a signal corresponding accurately to the temperature of the injectate fluid conducted through said lumen.

2. The temperature sensor of claim 1 wherein the sensor is snugly fitted in the enclosure.

3. The temperature sensor of claim 1 wherein said sensor is potted within a thermally conductive jacket.

4. The temperature sensor of claim 1 wherein said sensor is potted within a thermally conductive jacket carried on the end of an electrically conductive cable, said cable transmitting the sensed temperature signal.

5. The temperature sensor of claim 1 further including a retractable protective cover surrounding the temperature sensor, said cover protecting the sensor when separated from the enclosure.

6. The temperature sensor of claim 1 wherein said enclosure is bonded to the housing.

7. The temperature sensor of claim 1 wherein said enclosure comprises a separately formed element secured to said housing.

8. The temperature sensor of claim 1 wherein said housing defines a threaded connector coaxially of said enclosure and said sensor is provided in a cover having a threaded connector removably connected to said housing threaded connector.

9. The temperature sensor of claim 1 including means for resiliently urging the sensor into said enclosure.

10. The temperature sensor of claim 1 wherein said sensor has an external configuration complementary to said enclosure and is resiliently urged into a snug fit therein.

11. The temperature sensor of claim 1 wherein said housing is formed of a molded synthetic resin.

12. The temperature sensor of claim 1 wherein said enclosure is formed of stainless steel.

13. The temperature sensor of claim 1 wherein said sensor is mounted in a probe tube.

14. The temperature sensor of claim 1 wherein said sensor is mounted in a probe tube secured in a support base formed of a synthetic resin.

15. The temperature sensor of claim 1 wherein said sensor is mounted in a probe tube, lead wires being connected to said sensor and extending outwardly through said probe tube for connection to an electrical conductor cable.

16. The temperature sensor of claim 1 wherein said sensor comprises a thermistor.

17. The temperature sensor of claim 1 wherein said sensor is disposed in a probe tube and a retractable cover is yieldably disposed about the probe tube.

18. The temperature sensor of claim 1 wherein said enclosure extends substantially fully across said lumen.