US3971383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cryogenic surgical instrument
Assignee: Erbe Elecktromedizin GmbH
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Filing: 1975-04-29
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Granted: 1976-07-27
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Expires: 1995-04-29
Abstract
Abstract To insulate the supply lines to an operating tip of a cryogenic surgical instrument, a coaxial assembly of tubes is provided, the inner one being connected to a supply of cryogenic liquid, such as liquid nitrogen; the space between the outer wall of the inner tube and the next tube forming a return line for evaporated cryogenic liquid which is vented to the atmosphere; and the space between the outermost one of the coaxial tubes and the intermediate tube containing a gas such as normal butane, introduced at atmospheric pressure and which has high heat-insulating properties, and which solidifies, or sublimates, to avoid a vacuum and make possible construction of the supply lines as plastic, preferably polyamide tubes, retaining flexibility in use.
Inventors
- 👤 Johannes T. M. van Gerven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:19
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/02; A; A61; A61B; A61B18/00; A61B18/02; F25D; F25D3/00; F25D3/10; A61B17/00; A61B2017/00017; A61B2017/00022; A61B2017/00084; A61B2018/00005; A61B2018/00041; A61B2018/00053; A61B2018/00059; A61B2018/00089; A61B2018/00101; F25B2309/00; F25B2309/02; F25B2309/021
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
114 words
Cryogenic surgical instrument to supercool limited areas of biological tissue having a hollow tip (21) of thermally conductive material, a supply vessel (1) of supercooled cryogenic liquid, a supply line (11) connected to said supply vessel (1) and to the hollow interior of the tip (21), a return line coaxial with said supply line and surrounding the same, said return line comprising two coaxial tubes (13, 15) spaced from each other and defining a heat-insulating space (14) therebetween, the inner one of the coaxial tubes (13) being spaced from the supply line (11) to define a return space (12) for evaporated cryogenic liquid, and a filler material comprising n-butane in said insulating space (14).
Claim 2
Dependent Claim
114 words
Cryogenic surgical instrument to supercool limited areas of biological tissue having a hollow tip (21) of thermally conductive material, a supply vessel (1) of supercooled cryogenic liquid, a supply line (11) connected to said supply vessel (1) and to the hollow interior of the tip (21), a return line coaxial with said supply line and surrounding the same, said return line comprising two coaxial tubes (13, 15) spaced from each other and defining a heat-insulating space (14) therebetween, the inner one of the coaxial tubes (13) being spaced from the supply line (11) to define a return space (12) for evaporated cryogenic liquid, and a filler material comprising n-butane in said insulating space (14).
Claim 3
Dependent Claim
20 words
Instrument according to claim 1, further comprising additional filler material comprising insulating ceramic powder located in said insulating space (14).
Claim 4
Dependent Claim
19 words
Instrument according to claim 1, wherein at least one of said coaxial tubes (13, 15) comprises a polyamide tube.
Claim 5
Dependent Claim
21 words
Instrument according to claim 1, further comprising spacers (14') spacing said inner and outer coaxial tubes (13, 15) from each other.
Claim 6
Dependent Claim
23 words
Instrument according to claim 1, wherein the outermost one (15) of said coaxial tubes (13, 15) is directly connected to said tip (21).
Claim 7
Dependent Claim
31 words
Instrument according to claim 1, further comprising an insulating layer or cover (16) comprising foam material with closed cells surrounding the outer one of said coaxial tubes, at least in part.
Claim 8
Dependent Claim
32 words
Instrument according to claim 1, further comprising a filling (19) in the hollow interior of the cooling tip, said filling comprising a material including at least one of: silver wool; copper wool.
Claim 9
Dependent Claim
21 words
Instrument according to claim 1, further comprising a heating winding (18) located in the hollow interior of the cooling tip (21).
Claim 10
Dependent Claim
40 words
Instrument according to claim 1, further comprising a vent opening (9) communicating with the return space (12) between the supply line (11) and the inner one of said coaxial tubes (13), said vent opening being in communication with ambient atmosphere.
Claim 11
Dependent Claim
43 words
Instrument according to claim 1, further comprising a liquid barrier (20) in the interior of the cooling tip (21) in the path of the return space (12) to prevent escape of cryogenic substance in liquid phase from the interior of the cooling tip.
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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) | 1979-07-27 | 1980-01-26 | 1980-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-27 | 1984-01-26 | 1984-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-27 | 1988-01-26 | 1988-07-27 | $7700.00 | Window Closed / Lapsed |