Intravenous fluid warming system

• US 20060222350A1
• Filed: 03/21/2006
• Published: 10/05/2006
• Est. Priority Date: 03/21/2005
• Status: Active Grant

• Current Assignee: Vital Signs Incorporated (Becton, Dickinson & Co)
• Original Assignee: Enginivity LLC (Becton, Dickinson & Co)
• Inventors: Cassidy, David E.
• Granted Patent: US 7,865,072 B2
• Time in Patent Office: Days
• US Class Current: 392/470
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/44 having means for cooling or heating the devices or media

Abstract

A fluid warming device includes axially or longitudinally slidable covers that retain a removable heat exchange body in a housing in heat exchange communication with a heater assembly while allowing flow through the heat exchange body to be observed. In another aspect, a fluid warming system increases or decreases power to a heater assembly to adjust the fluid temperature to ensure that the fluid is at an appropriate temperature when it reaches the patient.

Claims

1. A fluid warming device comprising:

a housing comprising a main body and a pair of covers, the covers axially slidable on the main body, and a heat exchange body receiving compartment in the main body;

a heater assembly disposed within the main body; and

a heat exchange body removably disposable in the compartment of the main body in contact with a heat conducting surface of the heater assembly, the heat exchange body containing a fluid flow line from a fluid input port to a fluid output port;

wherein the covers are slidable axially on the main body to a closed position in which the covers press the heat exchanger into heat exchange communication with the heater assembly.

2. The fluid warming device of claim 1, wherein the covers contact edges of the heat exchange body in the closed position and leave a mid portion of the heat exchange body visible.

3. The fluid warming device of claim 1, wherein the covers are slidable to an open position from which the heat exchange body can be removed from or inserted into the compartment in the main body.

4. The fluid warming device of claim 3, wherein the heat exchange body can be removed from or inserted into the compartment while attached to IV tubing.

5. The fluid warming device of claim 1, wherein the covers are retained in the closed position by frictional engagement with the heat exchange body.

6. The fluid warming device of claim 1, wherein the covers are slidable to a half closed position in which the covers still retain the heat exchange body within the compartment in the main body.

7. The fluid warming device of claim 1, wherein the covers include a switch to activate power to the heater assembly when the covers are in the closed position.

8. The fluid warming device of claim 1, wherein the heat exchange body includes visible indicators thereon, and the covers do not block the visible indicators when in the closed position.

9. The fluid warming device of claim 1, wherein the covers are slidable on longitudinal tracks on the main body of the housing.

10. The fluid warming device of claim 1, wherein fluid flowing through the heat exchange body is visible.

11. The fluid warming device of claim 1, wherein the covers are slidable in opposite directions between a fully closed position and an open position.

12. The fluid warming device of claim 1, wherein the covers are fully removable from the main body.

13. The fluid warming device of claim 1, wherein the covers are retained on the main body by a retaining mechanism.

14. The fluid warming device of claim 13, wherein the retaining mechanism comprises complementary latching surfaces on the covers and the main body.

15. A fluid warming system to minimize heat loss through IV tubing to a patient, comprising:

a) determining a temperature drop across a heat exchange body of an IV fluid warming device;

b) determining a temperature drop of the IV tubing to the environment, the IV tubing extending from the IV fluid warming device to a patient;

c) determining if the temperature drop along the IV tubing is greater than a determined temperature limit;

d) determining if the total temperature drop along the IV tubing and across the heat exchange body is greater than a determined drop limit;

e) if the determined values from step c) and step d) are greater than their respective limits, determining the actual fluid temperature as a fluid output temperature minus the drop limit;

f) if either of the determined values from step c) and step d) are not greater than their respective limits, determining the actual fluid temperature as a fluid output temperature minus the heat exchanger temperature drop; and

g) adjusting power to the heat exchanger to achieve the desired output temperature.

16. The fluid warming system of claim 15, wherein the temperature drop across the heat exchanger in step a) is determined by dividing heater power of a heater assembly that heats the heat exchange body by the thermal resistance of the heater assembly.

17. The fluid warming system of claim 15, wherein the temperature drop of the IV tubing in step b) is determined by determining the difference between a fluid target temperature and ambient temperature, multiplying this difference by a radiation loss constant to get a result, and dividing the result by heater power of a heater assembly that heats the heat exchange body.

18. The fluid warming system of claim 15, wherein the determined temperature limit of step c) is 1°

C.

19. The fluid warming system of claim 15, wherein the determined drop limit of step d) is a maximum temperature to which the IV fluid can be heated.

20. the fluid warming system of claim 19, wherein the maximum temperature is 3°

C. above the desired temperature.

21. The fluid warming system of claim 15, wherein the fluid output temperature is measured by a temperature sensor on the IV fluid warming device.