Patent US3566875A successfully refreshed from Google Patents.
US3566875A
Expired / Lapsed
US
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Device for draining cerebrospinal fluid
Assignee: Individual
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Filing: 1969-05-20
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Granted: 1971-03-02
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Expires: 1989-05-20
Abstract
Abstract A device for draining cerebrospinal fluid automatically to the venous system in cases of hydrocephalus. The device includes an outer elastic tube which houses in its interior identically flow oriented upstream and downstream check (unidirectional) valves respectively communicating with the cerebrospinal fluid and the venous system. Each check valve includes an inner elastic tubular member within the outer tube and having an upstream open end and a downstream closed end. At the region of its downstream closed end each inner tubular member is formed with at least one axially extending slit which forms the outlet of the valve. Within each inner elastic tubular member is a freely movable ball member located in the region of the closed end of the inner tubular member where the slit is situated. A rigid tube is situated within each inner elastic tubular member and has a downstream end at a short distance from the closed end of the tubular member to provide the freely movable ball member with a restricted extent of axially free movement. Because of the free movability of this ball member within each check valve the interior thereof is kept clean, particularly at the region of the slits, and thus malfunctioning due to clot formations at the slit is reliably avoided. Moreover, since the slit extends to substantially the closed end of the tubular member, dead space in which blood can clot to obstruct flow is substantially eliminated and the danger of infection is substantially reduced.
Inventors
- 👤 Richard K Stoehr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:03
CPC Classifications
A; A61; A61M; A61M39/00; A61M39/22; A61M27/00; A61M27/002; A61M27/006; Y; Y10; Y10T; Y10T137/00; Y10T137/4238; Y10T137/4245; Y10T137/4273; Y10T137/7722; Y10T137/7837; Y10T137/7879; Y10T137/788; Y10T137/7882; Y10T137/7884
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
321 words
In a device for draining cerebrospinal fluid to the venous system, an elongated outer elastic tube; upstream and downstream identically flow oriented spaced check valves respectively located in said tube and each having an upstream inlet and a downstream outlet, means communicating with the upstream inlet of said upstream check valve for placing the latter in communication with cerebrospinal fluid, means communicating with the downstream outlet of said downstream check valve for placing the latter in communication with the venous system, and each check valve comprising an inner tubular elastic member housed within said outer elastic tube and having an open upstream end forming said inlet and a closed downstream end, said inner tubular member of each check valve being formed in the region of its closed downstream end with an axially extending slit which forms an outlet in response to an excess in the internal pressure of said inner tubular member with respect to the external pressure at the region of said slit for automatically opening the latter to provide for flow of fluid downstream through each inner tubular member out through said slit, each slit automatically closing in response to an increase in the external pressure over the internal pressure of said tubular member to prevent fluid from flowing in an upstream direction, a ball member situated in the interior of each inner tubular member in the region of said closed end thereof and being freely movable therein, and a substantially rigid tube situated in each inner tubular member and having a downstream end situated adjacent said ball member at a distance from the closed end of each inner tubular member sufficiently great to provide a predetermined extent of movement of the ball member, so that the moving ball member will maintain fluid in each inner elastic member in motion for preventing malfunctioning of said slit due to clotting and also eliminates dead space in the inner tubular member.
Claim 2
Dependent Claim
321 words
In a device for draining cerebrospinal fluid to the venous system, an elongated outer elastic tube; upstream and downstream identically flow oriented spaced check valves respectively located in said tube and each having an upstream inlet and a downstream outlet, means communicating with the upstream inlet of said upstream check valve for placing the latter in communication with cerebrospinal fluid, means communicating with the downstream outlet of said downstream check valve for placing the latter in communication with the venous system, and each check valve comprising an inner tubular elastic member housed within said outer elastic tube and having an open upstream end forming said inlet and a closed downstream end, said inner tubular member of each check valve being formed in the region of its closed downstream end with an axially extending slit which forms an outlet in response to an excess in the internal pressure of said inner tubular member with respect to the external pressure at the region of said slit for automatically opening the latter to provide for flow of fluid downstream through each inner tubular member out through said slit, each slit automatically closing in response to an increase in the external pressure over the internal pressure of said tubular member to prevent fluid from flowing in an upstream direction, a ball member situated in the interior of each inner tubular member in the region of said closed end thereof and being freely movable therein, and a substantially rigid tube situated in each inner tubular member and having a downstream end situated adjacent said ball member at a distance from the closed end of each inner tubular member sufficiently great to provide a predetermined extent of movement of the ball member, so that the moving ball member will maintain fluid in each inner elastic member in motion for preventing malfunctioning of said slit due to clotting and also eliminates dead space in the inner tubular member.
Claim 3
Dependent Claim
39 words
The combination of claim 1 and wherein said closed end of each inner tubular member is of a substantially hemispherical configuration and said slit extending in an axial plane through part only of said closed end of hemispherical configuration.
Claim 4
Dependent Claim
26 words
The combination of claim 2 and wherein each inner tubular member is formed with a pair of said slits which are diametrically opposed to each other.
Claim 5
Dependent Claim
65 words
The combination of claim 3 and wherein the distance between said slits at said closed end of each inner tubular member is equal to the inner diameter of the latter tubular member so that said slits have at said closed hemispherical end of each inner tubular member inner edges respectively forming continuations of the inner surface of said inner surface of said inner tubular member.
Claim 6
Dependent Claim
36 words
The combination of claim 1 and wherein said slit of each inner tubular member extends from the immediate vicinity of said closed end thereof in an upstream direction beyond said downstream end of said rigid tube.
Claim 7
Dependent Claim
100 words
The combination of claim 1 and wherein each inner tubular member has at its downstream closed end a pair of said slits diametrically opposed to each other and extending partly only into said closed end, said closed end being of a hemispherical configuration and said slits respectively terminating at said closed end in inner edges respectIvely forming continuations of the inner surface of said inner tubular member, said pair of diametrically opposed slits of each inner tubular member extending axially from said closed end thereof in an upstream direction at least about equal to the axial length of the slits.
Claim 8
Dependent Claim
60 words
The combination of claim 1 and wherein each rigid tube is formed at its downstream end with a circular end face to be engaged by said ball member during movement thereof in an upstream direction in each inner tubular member, so that said ball member and rigid tube also functions as an inner check valve to prevent back-flow of fluid.
Claim 9
Dependent Claim
14 words
The combination of claim 1 and wherein each ball member is made of nylon.
Claim 10
Dependent Claim
27 words
The combination of claim 8 and wherein said outer tube and inner tubular members are made of silicone rubber, said rigid tubes being made of stainless steel.
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |