US5405315A
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US
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Method for determining adequacy of dialysis based on urea concentration
Assignee: KHURI SOUMAYA M
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Filing: 1994-02-15
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Granted: 1995-04-11
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Expires: 2014-02-15
Abstract
Abstract A method for determining the adequacy of dialysis, using determination of urea concentration in the dialysate effluent with an enzymatic electrode incorporating a urease sensor, and conversion of this information to arterial urea nitrogen utilizing a "flow ratio" correction; and utilizing the arterial blood urea nitrogen derived from readings of an on-line monitoring sensor as an absolute quantity, and the urea reduction ratio as a relative quantity as a new end-point for dialysis adequacy.
Inventors
- 👤 Raja N. Khuri
- 👤 Nazih L. Nakhoul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:26
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/14; A61M1/16; A61M1/1601; A61M1/1603; A61M1/1605; A61M1/1609; A61M1/1619; A61M1/36; A61M1/3607; A61M1/3609; A61M2202/00; A61M2202/04; A61M2202/0496; A61M2202/0498; A61M2205/00; A61M2205/15; A61M2205/33; A61M2205/3303
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
84 words
A method for determining adequacy of dialysis of a patient, comprising: (a) providing an enzymatic urease-based sensor; (b) using said sensor to determine a concentration of urea in dialysate from said dialysis; (c) utilizing said urea concentration in said dialysate and selected physiological factors associated with the patient and with said dialysis to accurately determine a concentration of urea in arterial blood and to determine dialysis adequacy; and (d) ceasing dialysis of said patient when said dialysis is adequate as determined in step (c).
Claim 2
Independent Claim
84 words
A method for determining adequacy of dialysis of a patient, comprising: (a) providing an enzymatic urease-based sensor; (b) using said sensor to determine a concentration of urea in dialysate from said dialysis; (c) utilizing said urea concentration in said dialysate and selected physiological factors associated with the patient and with said dialysis to accurately determine a concentration of urea in arterial blood and to determine dialysis adequacy; and (d) ceasing dialysis of said patient when said dialysis is adequate as determined in step (c).
Claim 3
Dependent Claim
28 words
The method of claim 1 including conducting said steps on an ongoing basis and ceasing dialysis of said patient whenever dialysis of said patient is indicated as adequate.
Claim 4
Dependent Claim
30 words
The method for determining adequacy of dialysis of a patient according to claim 1, wherein said selected physiological factors comprise flow rates of venous blood, arterial blood and dialysate fluid.
Claim 5
Independent Claim
120 words
A method for determining adequacy of dialysis of a patient, comprising: (a) providing an enzymatic urease-based sensor; (b) using said sensor to determine a concentration of urea in dialysate from said dialysis; (c) utilizing said urea concentration in said dialysate and selected physiological factors associated with the patient and with said dialysis to accurately determine a concentration of urea in arterial blood and to determine dialysis adequacy; (d) calculating a urea reduction ratio; (e) utilizing the dialysis adequacy as an absolute quantity and the urea reduction ratio as a relative quantity as new end-points to determine when to cease dialysis; and (f) ceasing dialysis of said patient when said dialysis is adequate as determined in step (c) and step (e).
Claim 6
Independent Claim
120 words
A method for determining adequacy of dialysis of a patient, comprising: (a) providing an enzymatic urease-based sensor; (b) using said sensor to determine a concentration of urea in dialysate from said dialysis; (c) utilizing said urea concentration in said dialysate and selected physiological factors associated with the patient and with said dialysis to accurately determine a concentration of urea in arterial blood and to determine dialysis adequacy; (d) calculating a urea reduction ratio; (e) utilizing the dialysis adequacy as an absolute quantity and the urea reduction ratio as a relative quantity as new end-points to determine when to cease dialysis; and (f) ceasing dialysis of said patient when said dialysis is adequate as determined in step (c) and step (e).
Claim 7
Independent Claim
117 words
A method for determining adequacy of dialysis of a patient, comprising: (a) providing an enzymatic urease-based sensor electrode; (b) using said electrode to determine a concentration of urea in dialysate from said dialysis; (c) utilizing said urea concentration in said dialysate to obtain an arterial urea concentration; (d) using said arterial urea concentration to obtain a profile of urea reduction; (e) using said profile to assess dialysis adequacy; (f) calculating a urea reduction ratio; (g) utilizing the dialysis adequacy as an absolute quantity and the urea reduction ratio as a relative quantity to determine when to cease dialysis; and (h) ceasing dialysis of said patient when said dialysis is adequate as determined in steps (e) and (g).
Claim 8
Independent Claim
117 words
A method for determining adequacy of dialysis of a patient, comprising: (a) providing an enzymatic urease-based sensor electrode; (b) using said electrode to determine a concentration of urea in dialysate from said dialysis; (c) utilizing said urea concentration in said dialysate to obtain an arterial urea concentration; (d) using said arterial urea concentration to obtain a profile of urea reduction; (e) using said profile to assess dialysis adequacy; (f) calculating a urea reduction ratio; (g) utilizing the dialysis adequacy as an absolute quantity and the urea reduction ratio as a relative quantity to determine when to cease dialysis; and (h) ceasing dialysis of said patient when said dialysis is adequate as determined in steps (e) and (g).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-04-10 | 1998-10-10 | 1999-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-10 | 2002-10-10 | 2003-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-10 | 2006-10-10 | 2007-04-11 | $7700.00 | Window Closed / Lapsed |