Patent US2335906A successfully refreshed from Google Patents.
US4643192A
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US
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Hollow viscus tonometry
Assignee: Instrumentarium Oyj
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Filing: 1986-02-27
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Granted: 1987-02-17
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Expires: 2006-02-27
Abstract
Abstract Ischemia in a hollow internal organ can be detected in its incipient stages by obtaining a CO 2 sample from within the organ of interest, measuring the partial pressure of CO 2 sample, measuring the bicarbonate concentration of an arterial blood sample, and on the basis of these two measurements calculating the pH of the wall of the organ. The value of the pH is an indicator of the onset of ischemia in the organ. The CO 2 sample is obtained by a novel catheter, multiple embodiments of which are disclosed.
Inventors
- 👤 Richard G. Fiddian-Green
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:29
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/14542; A61B5/14539; A61M; A61M25/00; A61M25/10; A61M25/1011; A61M25/01; A61M2025/0177; A61M2025/1043; A61M2025/1061
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
201 words
A method for detecting the onset of ischemia in a hollow internal organ which comprises providing a catheter having a catheter tube; and a walled sampling chamber on the tube in communication with the interior of the tube; the wall of said walled sampling chamber comprising a material which is freely permeable to carbon dioxide gas in solution but poorly permeable to liquid fluid, introducing the catheter into the organ of interest so that the sampling chamber is disposed at a desired sampling site and leaving the sampling chamber disposed at the sampling site for a length of time sufficient to allow any carbon dioxide gas present at the sampling site to diffuse across the wall of the sampling chamber into aspirating liquid contained within the sampling chamber, withdrawing at least a portion of said aspirating liquid containing any diffused carbon dioxide gas via the catheter tube, analyzing the sample thus withdrawn for carbon dioxide, directly measuring the bicarbonate concentration of the article blood of the patient, determining of pH of said hollow internal organ at the sampling site on the carbon dioxide and bicarbonate measurements thus obtained, and determining whether ischemia is present on the basis of of pH determination.
Claim 2
Independent Claim
201 words
A method for detecting the onset of ischemia in a hollow internal organ which comprises providing a catheter having a catheter tube; and a walled sampling chamber on the tube in communication with the interior of the tube; the wall of said walled sampling chamber comprising a material which is freely permeable to carbon dioxide gas in solution but poorly permeable to liquid fluid, introducing the catheter into the organ of interest so that the sampling chamber is disposed at a desired sampling site and leaving the sampling chamber disposed at the sampling site for a length of time sufficient to allow any carbon dioxide gas present at the sampling site to diffuse across the wall of the sampling chamber into aspirating liquid contained within the sampling chamber, withdrawing at least a portion of said aspirating liquid containing any diffused carbon dioxide gas via the catheter tube, analyzing the sample thus withdrawn for carbon dioxide, directly measuring the bicarbonate concentration of the article blood of the patient, determining of pH of said hollow internal organ at the sampling site on the carbon dioxide and bicarbonate measurements thus obtained, and determining whether ischemia is present on the basis of of pH determination.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein the hollow internal organ is the gut.
Claim 4
Dependent Claim
17 words
A method according to claim 2 wherein the portion of the gut of interest is the colon.
Claim 5
Dependent Claim
18 words
A method according to claim 2 wherein the portion of the gut of interest is the small intestine.
Claim 6
Dependent Claim
17 words
A method according to claim 2 wherein the portion of the gut of interest is the stomach.
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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) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |