US4442846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distributed port bone-piercing cathode for electrically stimulated osteogenesis
Assignee: University of Pennsylvania
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Filing: 1981-11-10
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Granted: 1984-04-17
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Expires: 2001-11-10
Abstract
Abstract Disclosed is an improved bone-piercing cathode for providing electrical stimulation of osteogenesis at a plurality of locations. A conventional bone-piercing cathode is modified by adding a number of "ports" extending through the insulative covering to expose the cathode permitting a flow of osteogenesis stimulating current therethrough. In a preferred embodiment, seven ports are spaced three on one side and four on the other of a conventional bone-piercing cathode which is inserted into the fracture site. Sufficient current is supplied to the cathode in order to insure that each port as well as the insulation-bare wire junction can supply 20 microamperes of osteogenesis stimulating current into the body tissues. This permits bone growth stimulation adjacent a plurality of sites on the cathode.
Inventors
- 👤 Carl T. Brighton
- 👤 Jonathan Black
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:27
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/02; A61N1/04; A61N1/05; A61N1/18; A61N1/20; A61N1/205
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
A cathode for use in stimulating osteogenesis in the vicinity of a human fracture site when connected to a suitable current source, said cathode comprising: a biocompatible conductor means for drilling through bony tissue layers having at least one end; and biocompatible non-conducting means for insulating said conductor means, said insulating means generally covering said conductor means except in the vicinity of said at least one end, said insulating means further including means for defining at least one port in said insulating means exposing a portion of the surface of said conductor means.
Claim 2
Dependent Claim
93 words
A cathode for use in stimulating osteogenesis in the vicinity of a human fracture site when connected to a suitable current source, said cathode comprising: a biocompatible conductor means for drilling through bony tissue layers having at least one end; and biocompatible non-conducting means for insulating said conductor means, said insulating means generally covering said conductor means except in the vicinity of said at least one end, said insulating means further including means for defining at least one port in said insulating means exposing a portion of the surface of said conductor means.
Claim 3
Dependent Claim
42 words
A cathode in accordance with claim 1, wherein said conductor drilling means comprises: tip means, at said at least one end, for drilling through bone, said tip means having a width; and shaft means for transmitting drilling torque to said tip means.
Claim 4
Dependent Claim
29 words
A cathode in accordance with claim 2, wherein said insulating means generally covers said shaft means and has a width not greater than the width of said tip means.
Claim 5
Dependent Claim
25 words
A cathode in accordance with one of claims 1 through 3, wherein said port defining means defines a plurality of ports in said insulating means.
Claim 6
Dependent Claim
29 words
A cathode in accordance with claim 4 wherein said insulating means comprises Teflon® and said ports are hemispherical in shape, 0.41 mm in diameter and 0.20 mm in depth.
Claim 7
Dependent Claim
25 words
A cathode in accordance with claim 2 or claim 3, wherein said tip means comprises a flattened and sharpened end portion of said shaft means.
Claim 8
Dependent Claim
27 words
A cathode in accordance with claim 6, wherein said port defining means defines a plurality of ports in said insulating means and said insulating means comprises Teflon®.
Claim 9
Dependent Claim
45 words
A cathode in accordance with claim 7, wherein said width of said tip means is equal to a width of said shaft means including said insulating means and each of said ports is hemispherical in shape, 0.41 mm in diameter and 0.20 mm in depth.
References Cited (Backward Citations)
US3842841A
Cited
US3918440A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |