Filter for filtering human blood, especially in an extracorporeal circulatory system

• US 4,758,337 A
• Filed: 11/07/1986
• Issued: 07/19/1988
• Est. Priority Date: 11/23/1985
• Status: Expired due to Fees

• Current Assignee: Sartorius Gmbh
• Original Assignee: Sartorius Gmbh
• Inventors: Pradel, Gunter, Kohn, Heinz-Gerhard
• Primary Examiner(s): Hruskoci, Peter
• Assistant Examiner(s): JONES, WILLIAM G
• Application Number:
  US06/928,059
• Time in Patent Office: 620 Days
• Field of Search: 55/178, 210/188, 210/436, 210/438, 210/472, 210/493.1, 210/497.01, 210/94, 210/103, 210/149, 604/4
• US Class Current: 210/94
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: B01D 36/001 Filters in combination with devices for the removal of gas, air purge systems

Abstract

In a filter for filtering human blood, especially in an extracorporeal circulatory system, with a blood inlet, a blood outlet and a vertically directed, hollow, cylindrical filter element located between them and consisting of a filter, and in which the hollow, cylindrical filter element seals housing chambers located in the filter housing between the blood inlet and the blood outlet in such a manner from each other by means of its front surfaces that the blood can only flow through the filter element, whereby the blood inlet is located in the center of the housing and of the hollow, cylindrical filter element and a gas outlet is located at the highest point of the housing, the blood inlet runs axially through the hollow cylinder of the filter element as a central ascending tube and divides it cross section into a smaller ascending pipe section and into a settling chamber section for the blood which is several times larger. The settling chamber section empties in its extended axis into a cylindrical gas separation chamber which comprises a closable gas outlet. The blood outlet is provided in the area of the lowest active filter surface of the filter element as a horizontally projecting connection piece which communicates only with an annular space surrounding the outside of the filter element. The annular space is located in the area of the upper active filter surface of the filter element and comprises its own closable gas outlet at the highest point of an annular space, which runs preferably obliquely to the vertical filter axis.

Claims

1. A filter for filtering human blood in an extracorporeal circulatory system, comprising a housing having a blood inlet and a blood outlet, two housing parts permanently connected defining housing chambers and containing a receiving bearing which contains a temperature sensor for filtered blood a vertically directed hollow cylindrical filter element integrated therein, said filter element is located between the blood inlet and the blood outlet and seals, the housing chambers between the blood inlet and the blood outlet to allow blood to flow only through the filter element, whereby the blood inlet is axially located in the center of the housing as a central ascending pipe (3) and the hollow cylindrical filter element, and a gas outlet 12 is located at the highest point of the housing;

the hollow cylinder (4) of the filter element (5) empties in its axis of extension into a cylindrical gas separation chamber (11'"'"') which comprises the gas outlet (12) said gas outlet being closable and the blood outlet (18) is in the area of the lower end of the filter element (5) as an extending connection piece which communicates with the annular space (13) and with a second gas outlet (14) which annular space encloses the outer side of the filter element (5), wherein said gas separation chamber (11'"'"') is formed by an axial housing extension (11) and the latter is cylndrically formed in order to receive an enclosing gas bubble detector;

said housing comprises on an inner side of its upper and lower front surface of a formed receiving bearing (10) with a U-shaped cross section for front surfaces of the hollow cylindrical filter elements and sealing means (20) which connect the front surfaces to the housing.

2. The filter according to claim 1, wherein the annular space (13) is located in the area of the upper filter surface of the filter element (5), the second gas outlet (14) is closable and is located at the highest point of the annular space (13), which runs obliquely to the vertical filter axis.

3. The filter according to claim 1, wherein the blood outlet (18) is constructed as a horizontally extending connection piece and communicates with the annular space (13) via a vertical collection shaft (16).

4. The filter according to claim 3, wherein the vertical collection shaft (16) is formed by a radial housing convexity which is open to the filter element (5).

5. The filter according to claim 4, wherein the collection shaft (16) terminates axially in a closable opening (15) in one of the housing parts and said closable opening (15) and said collection shaft (16) form said receiving bearing for the temperature sensor (T) disposed therein.

6. The filter according to claim 5, wherein closable opening (15) with connection shaft (16) is located diametrically opposite said second gas outlet (14) of the annular space (13).

7. The filter according to claim 1, wherein the filter element (5) is formed by a single-layer or multi-layer cloth consisting of woven and non-woven plastic monofilaments folded in a plurality of folds.

8. The filter according to claim 1, wherein the housing (7,9) is formed from transparent plastic and the two housing parts (7,9) directly receive the hollow cylindrical filter element (5) and are permanently connected at their edges in a leakproof manner by an interlocking profiling.

9. The filter according to claim 1, wherein the ascending pipe (3) axially penetrates the hollow cylinder (4) of the filter element (5).