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US5879317A
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Electrostatic blood defoamer for heart-lung machines
Assignee: Medtronic Inc
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Filing: 1997-05-29
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Granted: 1999-03-09
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Expires: 2017-05-29
Abstract
Abstract In a heart-lung machine, blood is defoamed without the use of defoaming chemicals by passing blood between parallel insulated electrodes whose electric field orients the blood protein molecules to break up the foam bubbles. The blood then passes into the venous reservoir through a bubble screen which traps any remaining bubbles.
Inventors
- 👤 Sean D. Plunkett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:30
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/36; A61M1/3621; A61M1/3627; A61M1/14; A61M1/32; A61M1/322; A61M1/3666; A61M1/3667
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
79 words
A method of defoaming blood in a cardiotomy filter/defoamer having a defoaming chamber receiving blood from a top-mounted inlet and passing it through a filtering and defoaming medium, comprising the steps of: a) providing in said chamber a set of insulated electrode plates connected to a direct current voltage source so as to produce a static electric field therebetween, and b) causing said blood to pass through said electric field between said inlet and said filtering and defoaming medium.
Claim 2
Independent Claim
79 words
A method of defoaming blood in a cardiotomy filter/defoamer having a defoaming chamber receiving blood from a top-mounted inlet and passing it through a filtering and defoaming medium, comprising the steps of: a) providing in said chamber a set of insulated electrode plates connected to a direct current voltage source so as to produce a static electric field therebetween, and b) causing said blood to pass through said electric field between said inlet and said filtering and defoaming medium.
Claim 3
Dependent Claim
19 words
The method of claim 1, in which said electric field has a field strength of substantially 10 4 V/cm.
Claim 4
Dependent Claim
24 words
The method of claim 2, in which said set of electrode plates consists of a plurality of interleaved closely spaced electrodes of alternating potential.
Claim 5
Dependent Claim
24 words
The method of claim 3, in which blood flow through said electric field is maximized by disposing said electrode plates vertically in said chamber.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-08 | 2002-09-07 | 2003-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-08 | 2006-09-07 | 2007-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-08 | 2010-09-07 | 2011-03-09 | $7700.00 | Window Closed / Lapsed |