Intravenous-line air-elimination system

• US 5,935,105 A
• Filed: 10/30/1997
• Issued: 08/10/1999
• Est. Priority Date: 11/15/1991
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Faust, Valentine, Kamen, Dean L., Larkins, William T., Manning, Robert, Houle, Philip
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US08/961,410
• Time in Patent Office: 649 Days
• Field of Search: 604/122, 604/118, 604/131, 604/149, 604/28, 604/30, 604/31, 604/65, 604/123, 604/151, 604/153
• US Class Current: 604/122
• CPC Class Codes: A61M 2005/1402 Priming
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/35 Communication
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 5/1413 Modular systems comprising interconnecting elements
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/16809 by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/16877 Adjusting flow; Devices for setting a flow rate
• 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 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F16K 31/005 Piezoelectric benders
• CPC Class Codes: G01N 2291/02433 Gases in liquids, e.g. bubbles, foams
• CPC Class Codes: G01N 2291/02836 Flow rate, liquid level
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00

Abstract

An air elimination system is provided for an intravenous fluid delivery system for intravenous injection of fluid into a patient. An air-detection apparatus is disposed in an intravenous fluid line. At the top end of the line is attached a chamber where air may be separated from the fluid. The separation chamber may be a drip chamber, a metering chamber or the intravenous supply. When air is detected, a valve or valves are switched, so that the intravenous fluid is prevented from flowing to the patient, and so that, when a pump is turned on, the fluid is pumped to the separation chamber. In a preferred embodiment, the volume of pump'"'"'s fluid capacity is greater than the volume of the fluid capacity of the intravenous line between the pump and the separation chamber so that the pump can force air back up the intravenous line all the way to the separation chamber.

Claims

1. An air-elimination system, for a fluid delivery system for injection of intravenous fluid into a patient, comprising:

separation means for permitting the separation of air from the intravenous fluid;

an intravenous line in fluid communication with the separation means;

air-detection means, disposed in the intravenous line, for detecting air in the fluid and emitting a fault-condition signal, the intravenous line having a first portion between the separation means and the air-detection means, and a second portion between the air-detection means and the patient;

valve means, disposed in the intravenous line'"'"'s second portion, for permitting or preventing flow to the patient;

pump means for urging fluid towards the separation means upon activation; and

control means, in communication with the air-detection means, for (i) setting the valve means to prevent flow to the patient and activating the pump means, so as to move the fluid containing air from the air-detection means to the separation means, in response to a fault-condition signal, and otherwise (ii) setting the valve means to permit flow to the patient.

2. A system according to claim 1, wherein the pump means includes a pump disposed in the intravenous line upstream from the valve means.

3. A system according to claim 2, wherein the pump means includes a chamber disposed in the intravenous line, wherein pressure may be applied to the fluid in the chamber.

4. A method for eliminating air from an intravenous fluid delivery system, comprising the steps of:

providing a separation chamber where air may separate from the fluid;

providing an intravenous line downstream of the separation chamber;

providing an air detector in the intravenous line;

providing a pump in the intravenous line;

providing a valve in the intravenous line downstream of the pump and the air detector;

using the air detector to detect air in the fluid;

generating a signal when a specified amount of air is detected in the fluid;

closing the valve in response to the signal;

using the pump to urge fluid upstream through the intravenous line to the separation chamber in response to the signal.

5. A chamber for the removal of air bubbles in a liquid, the chamber comprising:

a rigid portion defining part of the chamber;

a flexible portion connected to the rigid portion and further defining the chamber such that, when external pressure is applied to the flexible portion, the flexible portion collapses toward the rigid portion forcing the liquid out of the chamber; and

a port defined by the rigid portion and located at the upper end of the chamber, the port increasing in cross-sectional area nearer the chamber so as to reduce the likelihood that a bubble will stick to an edge of the port;

wherein the port is shaped and sized so that, when the liquid is forced out from the chamber through the port, the liquid'"'"'s surface tension forces a bubble located at the port through the port without allowing the liquid to flow by the bubble easily.

6. A control unit for receiving a cassette mounted in an intravenous line, the control unit comprising:

a housing;

means, located on the housing, for receiving and actuating the cassette;

means, located on the housing, for mounting the control unit to a pole, such that a plurality of control units may be mounted one above the other on the same pole, in order to control several intravenous lines leading to a patient;

AC means for receiving AC power from a wall outlet and converting the AC power to DC power, the AC means being connected to the control unit housing by a first cord for carrying DC power; and

DC means for receiving DC power from a second control unit mounted on the same pole, wherein the second control unit is connected to a wall outlet, wherein the DC means receives the DC power through a second cord for carrying DC power.

7. A control unit according to claim 6, wherein the second cord includes wires for carrying electrical signals between control units.

8. A control unit for receiving a cassette mounted in an intravenous line, the control unit comprising:

a housing;

means, located on the housing, for receiving and actuating the cassette;

means, located on the housing, for mounting the control unit to a pole;

AC means for receiving AC power from a wall outlet and converting the AC power to DC power;

internal-battery means for providing DC power when the AC means is disconnected from the wall outlet, the internal battery means being located inside the housing; and

external-battery-receiving means for permitting an external battery pack to be connected to the housing'"'"'s exterior to provide power to the control unit in lieu of AC power from a wall outlet and from the internal-battery means.