Gas removal in an intravenous fluid delivery system

• US 20060025725A1
• Filed: 05/27/2005
• Published: 02/02/2006
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Vital Signs Incorporated (Becton, Dickinson & Co)
• Original Assignee: General Electric Company
• Inventors: Cassidy, David E.
• Granted Patent: US 7,547,295 B2
• Time in Patent Office: Days
• US Class Current: 604/253
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3386 Low level detectors
• CPC Class Codes: A61M 5/1411 Drip chambers A61M5/162, A61M5/1689, A61M5/40 take precedence
• CPC Class Codes: A61M 5/16813 by controlling the degree of opening of the flow line
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281
• CPC Class Codes: A61M 5/385 using hydrophobic filters
• CPC Class Codes: A61M 5/40 using low-level float-valve to cut off media flow from reservoir position detection of a floating member A61M5/1685
• CPC Class Codes: A61M 5/44 having means for cooling or heating the devices or media

Abstract

An active gas removal system is provided to remove air or gas bubbles from an intravenous fluid prior to infusion into the patient. The system detects the level of liquid in a drip chamber and occludes a downstream valve to the patient, thereby increasing pressure in the drip chamber sufficient to open a vent valve and release gas therein.

Claims

1. A system for the removal of gas bubbles from an intravenous liquid flowing in intravenous tubing, the system comprising:

a drip chamber having an inlet connected to intravenous tubing from an intravenous source and an outlet connected to intravenous tubing to a patient, the inlet disposed at a higher level than the outlet, wherein the drip chamber retains gas at an upper portion thereof;

a liquid level sensor operative to sense the level of liquid in the drip chamber;

a vent valve at an upper portion of the drip chamber operative to open upon a predetermined increase of gas pressure within the drip chamber;

a pump upstream of the drip chamber operative to pump the intravenous liquid from the source to the patient;

an occlusion valve downstream of the drip chamber operative to stop liquid flow in the intravenous tubing from the drip chamber to the patient; and

a controller in communication with the liquid level sensor and the downstream valve and operative to close the downstream valve upon detection of a specified liquid level in the drip chamber detected by the liquid level sensor, whereby continued operation of the upstream pump while the downstream valve is closed causes an increase of pressure in the drip chamber sufficient to open the vent valve and release gas in the drip chamber.

2. The system of claim 1, wherein the vent valve comprises a check valve.

3. The system of claim 1, wherein the vent valve comprises an umbrella check valve.

4. The system of claim 1, further comprising a hydrophobic filter disposed before the vent valve to prevent the intravenous fluid passing through the vent valve.

5. The system of claim 1, wherein the controller is further operative to open the occlusion valve.

6. The system of claim 1, wherein the liquid level sensor comprises a variable level sensor to detect a high liquid level and a low liquid level in the drip chamber and the controller is operative to provide an indication of detection of a predetermined high liquid level.

7. The system of claim 1, further comprising a further liquid level sensor operative to detect a high liquid level in the drip chamber and the controller is operative to provide an indication of detection of a predetermined high liquid level.

8. In an intravenous system including a drip chamber having an inlet connected to intravenous tubing from an intravenous source and an outlet connected to intravenous patient tubing, wherein the drip chamber retains gas at an upper portion thereof, and a pump upstream of the drip chamber operative to pump intravenous liquid from the source to the patient, a method for removal of gas in the drip chamber, the method comprising:

providing a liquid level sensor for sensing liquid level in the drip chamber;

providing a vent valve at an upper portion of the drip chamber;

providing a valve downstream of the drip chamber;

closing the downstream valve in response to a predetermined liquid level sensed by the sensor to cause an increase in pressure in the drip chamber sufficient to open the vent valve and release gas from the chamber; and

after release of gas from the chamber, opening the downstream valve.

9. The method of claim 8, further comprising:

sensing a low liquid level and a high liquid level in the drip chamber; and

providing an indication of detection of a predetermined high liquid level.

10. A method for removal of gas from an intravenous fluid line in an intravenous fluid infusion system, comprising:

providing an intravenous infusion system comprising an intravenous fluid line, a pump to deliver intravenous fluid to a patient through the intravenous fluid line, and a drip chamber downstream of the pump, a vent valve disposed at an upper portion of the drip chamber;

pumping the intravenous fluid to a patient through the fluid line;

collecting intravenous fluid in a bottom portion of the drip chamber prior to infusion to the patient and retaining gas in an upper portion of the drip chamber;

sensing a liquid level in the drip chamber;

occluding the fluid line at a location downstream of the drip chamber in response to a predetermined level in the drip chamber sensed by the sensor sufficient to cause an increase in pressure in the drip chamber by continued operation of the pump to open the vent valve and release gas from the drip chamber; and

after release of gas from the chamber, opening the fluid line to allow fluid flow to resume through the fluid line.

11. The method of claim 10, further comprising sensing a low liquid level and a high liquid level in the drip chamber;

and

providing an indication of detection of a predetermined high liquid level.