US3842841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant current power pack for bone healing and method of use
Assignee: United States Department of the Navy
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Filing: 1971-10-29
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Granted: 1974-10-22
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Expires: 1991-10-29
Abstract
Abstract Bone fracture healing through use of direct current of from 5 to 20 microamperes applied between a cathode inserted into a fracture or the site of a bone defect and an anode taped to the skin near the cathode implantation site is disclosed. A power source capable of delivering such current constantly despite increasing tissue resistance also is provided.
Inventors
- 👤 C Brighton
- 👤 Z Friedenberg
- 👤 W Redka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:17
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/24; A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61N; A61N1/00; A61N1/18; A61N1/20; A61N1/205
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
111 words
A system for expediting the healing of bone fractures and bone defects in a living being comprising: constant current source means for providing a constant value of current despite changes in load; means for connecting said constant current means to the living being, such connection acting to produce current flow into said fracture or defect, said connecting means including further means for application internally of said living being at the fracture or defect site, said constant current being a selected value within a predetermined microampere range so as to promote bone formation at the fracture or bone defect site and avoid fibrous tissue formation in other areas of the living being.
Claim 2
Independent Claim
111 words
A system for expediting the healing of bone fractures and bone defects in a living being comprising: constant current source means for providing a constant value of current despite changes in load; means for connecting said constant current means to the living being, such connection acting to produce current flow into said fracture or defect, said connecting means including further means for application internally of said living being at the fracture or defect site, said constant current being a selected value within a predetermined microampere range so as to promote bone formation at the fracture or bone defect site and avoid fibrous tissue formation in other areas of the living being.
Claim 3
Dependent Claim
34 words
The system as defined in claim 1 wherein said connecting means includes means for external application to the skin surface, the internal means being a cathodic electrode, the external means being an anodic electrode.
Claim 4
Dependent Claim
32 words
The system as defined in claim 1 wherein said constant current means comprises miniature solid state means suitable for mounting on the living being in close proximity to said fracture or defect.
Claim 5
Dependent Claim
18 words
The system as defined in claim 1 wherein said cathodic electrode is positionable within said fracture or defect.
Claim 6
Dependent Claim
23 words
The system as defined in claim 1 wherein said current is in the range of from substantially 5 microamperes to substantially 20 microamperes.
Claim 7
Independent Claim
202 words
A system for supplying a constant current within a selected amperage range to a bone fracture or a bone defect in a living being to promote healing thereof comprising: a pair of n-channel field-effect transistors, each having a source, drain and gate electrode; a dc power source, having a positive and a negative terminal, the drain electrode of one of said transistors being connected to the positive terminal of said power source and the source electrode of said one transistor being connected to the drain electrode of the other of said transistors; a variable resistor; the gate electrode of said one transistor and the source electrode of said other transistor being connected to one side of said variable resistor; means for connecting the negative terminal of said power source to the site of a bone fracture or bone defect; and means for completing the electrical circuit through the living being to a junction of the gate electrode of said other transistor and the other side of said variable resistor, the value of said variable resistor being adjusted for the desired current value of the cascaded transistors and the current valve being maintained notwithstanding changes in impedance across the fracture or defect tissue.
Claim 8
Independent Claim
202 words
A system for supplying a constant current within a selected amperage range to a bone fracture or a bone defect in a living being to promote healing thereof comprising: a pair of n-channel field-effect transistors, each having a source, drain and gate electrode; a dc power source, having a positive and a negative terminal, the drain electrode of one of said transistors being connected to the positive terminal of said power source and the source electrode of said one transistor being connected to the drain electrode of the other of said transistors; a variable resistor; the gate electrode of said one transistor and the source electrode of said other transistor being connected to one side of said variable resistor; means for connecting the negative terminal of said power source to the site of a bone fracture or bone defect; and means for completing the electrical circuit through the living being to a junction of the gate electrode of said other transistor and the other side of said variable resistor, the value of said variable resistor being adjusted for the desired current value of the cascaded transistors and the current valve being maintained notwithstanding changes in impedance across the fracture or defect tissue.
Claim 9
Dependent Claim
47 words
The system as defined in claim 6 wherein said means for connecting the negative terminal comprises a cathodic electrode for implantation in the fracture or defect and said means for completing the electrical circuit comprises an anodic electrode for application to the skin of the living being.
Claim 10
Dependent Claim
39 words
The system as defined in claim 6 wherein said power source is a 7-volt battery, and said battery, said field-effect transistors and said variable resistor can provide a current output in the range of from 1 to 20 microamperes.
Claim 11
Dependent Claim
55 words
The system as defined in claim 6 wherein the current through said fracture or defect site is constant at a selected value in the range of from 5 microamperes to 20 microamperes to promote bone formation in the region of said cathodic electrode and avoid fibrous tissue formation in the region of said anodic electrode.
Claim 12
Dependent Claim
27 words
The system as defined in claim 6 wherein said power source is suitable for mounting on the living being in close proximity to said fracture or defect.
Claim 13
Independent Claim
87 words
The method of promoting the healing of a bone fracture or bone defect in a living being comprising: inserting a first electrode into a site within the fracture or defect; applying a second electrode to the skin surface of the living being at a location in the vicinity of said fracture or defect; connecting constant dc current means across said electrodes, thereby producing a constant flow of current therebetween, regardless of load changes; and adjusting said current flow to a predetermined value between 5 and 20 microamperes.
Claim 14
Independent Claim
87 words
The method of promoting the healing of a bone fracture or bone defect in a living being comprising: inserting a first electrode into a site within the fracture or defect; applying a second electrode to the skin surface of the living being at a location in the vicinity of said fracture or defect; connecting constant dc current means across said electrodes, thereby producing a constant flow of current therebetween, regardless of load changes; and adjusting said current flow to a predetermined value between 5 and 20 microamperes.
Claim 15
Dependent Claim
25 words
The method of claim 11 including the step of mounting the current means on the living being in close proximity to the fracture or defect.
Claim 16
Dependent Claim
18 words
The method claim 11 wherein said first electrode is connected to the negative terminal of said current source.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |