Patent US3756234A successfully refreshed from Google Patents.
US3756234A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single needle dialysis
Assignee: Vital Assists Inc
•
Filing: 1971-06-04
•
Granted: 1973-09-04
•
Expires: 1991-06-04
Abstract
Abstract Method and apparatus for extracorporeally dialyzing the blood of a patient with only a single venipuncture including withdrawing blood from the patient through the venipuncture and forcing the blood along an arterial path to a dialyzer. Blood emerging from the dialyzer is then conducted along a venous path again to the venipuncture. The pressure is monitored in the extracorporeal system to trigger occluding devices which alternately open and close the arterial and venous paths so that undialyzed blood is taken from the patient and dialyzed blood is injected into the patient. The apparatus includes clamps actuated by a pressure monitor to alternately obstruct the arterial and venous paths. A blood pump may be controlled to operate as one of the clamps. In an alternative embodiment, blood is circulated at a comparatively high flow rate throughout the system. A clamp is provided in one of the arterial or venous lines, said clamp being controlled by a pressure monitor. When the clamp is closed, a pressure differential is developed between the extracorporeal system and the patient so that a volume of blood is exchanged between the system and the patient.
Inventors
- 👤 K Kopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:38
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/36; A61M1/3621; A61M1/3639; A61M1/14; A61M1/30; A61M1/301; A61M1/305; A61M1/306
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
219 words
A method of dialyzing the blood of a patient with a single cannula dialysis system having a dialyzer, a blood pump acting thereon and openable clamp comprising the steps of: cannulating the patient by placing a single cannula into the bloodstream of the patient; providing an extracorporeal bifurcated flow path in communication with the cannula, the flow path having an arterial branch, a venous branch and the blood dialyzer interposed therebetween; continuously pumping the blood in the arterial branch toward the dialyzer with a pump acting upon the arterial branch; creating two pressure zones by situating the openable clamp along the length of the venous branch, the first pressure zone defined by the portion of the flow path downstream from the pump and upstream from the clamp so as to include the dialyzer and the second pressure zone being defined by the portion of the flow path upstream from the pump and downstream from the clamp so as to include the patient cannula; developing increased pressure in the first zone and simultaneously decreasing pressure in the second zone by closing the clamp and continuously pumping blood in the arterial line so as to draw blood from the patient; and thereafter equalizing the pressure between the zones by opening the clamp thereby permitting blood to be transferred to the patient.
Claim 2
Independent Claim
219 words
A method of dialyzing the blood of a patient with a single cannula dialysis system having a dialyzer, a blood pump acting thereon and openable clamp comprising the steps of: cannulating the patient by placing a single cannula into the bloodstream of the patient; providing an extracorporeal bifurcated flow path in communication with the cannula, the flow path having an arterial branch, a venous branch and the blood dialyzer interposed therebetween; continuously pumping the blood in the arterial branch toward the dialyzer with a pump acting upon the arterial branch; creating two pressure zones by situating the openable clamp along the length of the venous branch, the first pressure zone defined by the portion of the flow path downstream from the pump and upstream from the clamp so as to include the dialyzer and the second pressure zone being defined by the portion of the flow path upstream from the pump and downstream from the clamp so as to include the patient cannula; developing increased pressure in the first zone and simultaneously decreasing pressure in the second zone by closing the clamp and continuously pumping blood in the arterial line so as to draw blood from the patient; and thereafter equalizing the pressure between the zones by opening the clamp thereby permitting blood to be transferred to the patient.
Claim 3
Independent Claim
217 words
A method of dialyzing the blood of a patient with a single cannula dialysis system having a dialyzer, a blood pump acting thereon and openable clamp comprising the steps of: cannulating the patient by placing a single cannula into the bloodstream of the patient; providing an extracorporeal bifurcated flow path in communication with the cannula, the flow path having an arterial branch, a venous branch and the blood dialyzer interposed therebetween; continuously pumping the blood in the arterial branch toward the dialyzer with a pump acting upon the arterial branch; creating two pressure zones by situating the openable clamp in the arterial line upstream from the pump, the first pressure zone being defined by the portion of the flow path downstream from the pump and upstream from the clamp so as to include both the patient cannula and the dialyzer and the second pressure zone being defined by the portion of the flow path upstream from the pump and downstream from the clamp; developing increased pressure in the first zone by continuously pumping the blood while closing the clamp thereby increasing the pressure in the first zone to inject blood into the patient; and equalizing the pressure between the zones by opening the clamp and permitting blood to be transferred from the patient to the flow path.
Claim 4
Independent Claim
217 words
A method of dialyzing the blood of a patient with a single cannula dialysis system having a dialyzer, a blood pump acting thereon and openable clamp comprising the steps of: cannulating the patient by placing a single cannula into the bloodstream of the patient; providing an extracorporeal bifurcated flow path in communication with the cannula, the flow path having an arterial branch, a venous branch and the blood dialyzer interposed therebetween; continuously pumping the blood in the arterial branch toward the dialyzer with a pump acting upon the arterial branch; creating two pressure zones by situating the openable clamp in the arterial line upstream from the pump, the first pressure zone being defined by the portion of the flow path downstream from the pump and upstream from the clamp so as to include both the patient cannula and the dialyzer and the second pressure zone being defined by the portion of the flow path upstream from the pump and downstream from the clamp; developing increased pressure in the first zone by continuously pumping the blood while closing the clamp thereby increasing the pressure in the first zone to inject blood into the patient; and equalizing the pressure between the zones by opening the clamp and permitting blood to be transferred from the patient to the flow path.
References Cited (Backward Citations)
US2474665A
Cited
US2625932A
Cited
US2659368A
Cited
US2721732A
Cited
US2927582A
Cited
US3416664A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |