US4601830A
Expired / Lapsed
US
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Method for dialysis
Assignee: United States Department of Veterans Affairs
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Filing: 1981-10-28
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Granted: 1986-07-22
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Expires: 2001-10-28
Abstract
Abstract A method and apparatus for the hemodialysis of the blood of kidney failure patients. The concentration of the dialysis solution is initially selected so that the solution osmolality approximates the osmolality of the patient's blood. The dialysis solution concentration is then reduced linearly as a function of time as the dialysis is carried out. The conductivity of the dialysis solution is measured and compared with high and low limit references. If the conductivity is outside the limits, an alarm is given and the concentration of the dialysis solution is held constant. A timer controls a proportional pumping means to reduce the concentration of the dialysis solution and concurrently reduces the conductivity reference limits for the alarm.
Inventors
- 👤 Wei-Tzuoh Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:48
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/14; A61M1/16; A61M1/1654; A61M1/1656
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
70 words
In the hemodialysis of blood by circulation of a dialysis solution in molecular exchange relation with blood to reduce the osmolality of the blood, the improvement comprising: initiating the hemodialysis with a dialysis solution having an osmolality of the order of the osmolality of the patient's blood; and thereafter varying the osmolality of the dialysis solution as a function of time to achieve the desired osmolality for the patient's condition.
Claim 2
Dependent Claim
70 words
In the hemodialysis of blood by circulation of a dialysis solution in molecular exchange relation with blood to reduce the osmolality of the blood, the improvement comprising: initiating the hemodialysis with a dialysis solution having an osmolality of the order of the osmolality of the patient's blood; and thereafter varying the osmolality of the dialysis solution as a function of time to achieve the desired osmolality for the patient's condition.
Claim 3
Dependent Claim
19 words
The hemodialysis method of claim 1 in which the osmolality of the dialysis solution is reduced continuously with time.
Claim 4
Dependent Claim
61 words
The hemodialysis method of claim 1 including the steps: establishing upper and lower conductivity limits for the dialysis solution; varying both limits in accordance with the variation of the conductivity of the dialysis solution as the osmolality thereof is changed; and initiating an alarm in the event the conductivity of the dialysis solution is outside said upper and lower conductivity limits.
Claim 5
Dependent Claim
31 words
The hemodialysis method of claim 3 in which the osmolality of the dialysis solution is reduced linearly with time and the upper and lower conductivity limits are reduced linearly with time.
Claim 6
Dependent Claim
139 words
In the hemodialysis of blood by circulation of a dialysis solution in molecular exchange relation with blood to reduce the osmolality of the blood, the improvement comprising: mixing a concentrated dialysis solution with water for circulation of the dialysis solution mixture through a dialyzer; establishing an initial concentration of said dialysis solution mixture having an osmolality of the order of the osmolality of the patient's blood; reducing the concentration of the dialysis solution mixture as a function of time; measuring the conductivity of the dialysis solution mixture; establishing initial upper and lower conductivity limits; reducing said upper and lower conductivity limits as a function of time; comparing the dialysis solution mixture conductivity with said upper and lower conductivity limits; and initiating an alarm if the dialysis solution mixture conductivity is below the lower limit or above the upper limit.
Claim 7
Dependent Claim
139 words
In the hemodialysis of blood by circulation of a dialysis solution in molecular exchange relation with blood to reduce the osmolality of the blood, the improvement comprising: mixing a concentrated dialysis solution with water for circulation of the dialysis solution mixture through a dialyzer; establishing an initial concentration of said dialysis solution mixture having an osmolality of the order of the osmolality of the patient's blood; reducing the concentration of the dialysis solution mixture as a function of time; measuring the conductivity of the dialysis solution mixture; establishing initial upper and lower conductivity limits; reducing said upper and lower conductivity limits as a function of time; comparing the dialysis solution mixture conductivity with said upper and lower conductivity limits; and initiating an alarm if the dialysis solution mixture conductivity is below the lower limit or above the upper limit.
Claim 8
Dependent Claim
30 words
The hemodialysis method of claim 5 in which the concentration of the dialysis solution mixture and the upper and lower conductivity limits are reduced continuously as a function of time.
References Cited (Backward Citations)
US4153554A
Cited
DE2825134A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |