Top flow bubble trap method

• US 5,674,199 A
• Filed: 09/21/1995
• Issued: 10/07/1997
• Est. Priority Date: 11/29/1993
• Status: Expired due to Term

• Current Assignee: Gambro Renal Products, Inc. (Baxter International Inc.)
• Original Assignee: Cobe Cardiovascular Incorporated (LivaNova Plc)
• Inventors: Brugger, James Myron
• Primary Examiner(s): Bhat, Nina
• Application Number:
  US08/531,784
• Time in Patent Office: 747 Days
• Field of Search: 422/44, 604/4, 604/29, 604/83, 604/80, 604/52, 604/122, 95/260, 210/239, 96/197, 96/204, 128/DIG. 3
• US Class Current: 604/122
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 2205/7545 for solid matter, e.g. microaggregates
• CPC Class Codes: A61M 2206/11 Laminar flow

Abstract

An apparatus for trapping bubbles in blood flowing in a circuit, such as blood in an extracorporeal circuit, is provided. The apparatus includes a housing which defines a substantially vertical chamber. Blood is introduced into the chamber through an inlet tube extending downwardly into the chamber and is removed from the chamber at an exit port near the lower end of the housing. A diverter having a container base and rim is positioned within the chamber. Blood is introduced near the container base. The blood is redirected upward upon contact with the container base and is then redirected downward over the rim. The redirection of blood flow provides an opportunity for bubbles in the blood to separate from the blood in the chamber and also helps prevent stagnation of blood in the chamber which might otherwise lead to clotting and separation of the blood.

Blood is introduced into a chamber of the apparatus in a generally downward direction below the level of blood already present in the chamber. The blood is then directed in a generally upward direction, after which it is redirected in a generally downward direction. The reversal of blood flow provides an opportunity for bubbles in the blood to separate from the blood. Thereafter the blood and bubbles are collected.

Claims

1. A method of removing bubbles from blood flowing through a bubble trap apparatus in a circuit comprising the steps of:

providing a bubble trap apparatus comprising a housing defining an elongated, substantially vertical primary chamber and having an upper housing end and a lower housing end;

maintaining an upper blood surface of the blood in the primary chamber intermediate between the upper and lower housing ends;

introducing blood in a downward direction into the primary chamber below the upper blood surface and above the lower housing end;

redirecting the downwardly flowing blood in the primary chamber to flow in a substantially upward direction;

separating bubbles in the blood;

allowing the bubbles to rise to the upper blood surface;

redirecting the upwardly flowing blood to flow in a substantially downward direction, to provide further opportunity for bubbles in the blood to separate from the blood and rise to the upper blood surface;

collecting the blood near the lower housing end; and

collecting the bubbles above the upper blood surface.

2. The method of claim 1 further comprising the steps of:

disposing a container within the primary chamber to define a secondary chamber into which the blood is introduced; and

filling the secondary chamber with blood.

3. The method of claim 1 wherein the steps of redirecting the blood flow downward and redirecting the blood flow upward are carried out by means of a container disposed within the primary chamber below the upper blood surface.

4. The method of claim 1 wherein the steps of redirecting the blood flow upward and redirection the blood flow downward are carried out by means of a container disposed adjacent to the primary chamber.

5. The method of claim 1 wherein the step of redirecting the downwardly flowing blood in the primary chamber to flow in a substantially upward direction involves the redirection of substantially all of the downwardly flowing blood.

6. The method of claim 1 wherein the step of maintaining the upper blood surface in the primary chamber intermediate between the upper and lower housing ends is performed both before and after the blood introducing step.