Patent US4963150B1 successfully refreshed from Google Patents.
US3784908A
Expired / Lapsed
US
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Electrical conductivity measurement method and apparatus
Assignee: Individual
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Filing: 1973-04-09
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Granted: 1974-01-08
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Expires: 1993-04-09
Abstract
Abstract A method and apparatus is disclosed for minimization of the effect of contact potential and polarization at the electrodes while making electrical conductivity measurements of animal tissue samples. A current driven by an alternating polarity voltage source is passed through the sample. The polarity of the voltage source is reversed after a predetermined amount of charge has passed through the sample such that in one complete cycle equal amounts of charge have passed through the sample in opposite directions. The value of the sample conductivity is determined by the frequency of the alternating polarity voltage source.
Inventors
- 👤 W Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:26
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; A; A61; A61B; A61B5/00; A61B5/05; A61B5/053; A61B5/0531; A61B5/0532
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
89 words
The method of indicating electrical conductance between two points of animal tissue which form an electrical current path comprising the steps of: a. making electrical contact to said animal tissue at each of said two points, b. flowing a predetermined amount of charge through said electrical current path in one direction, c. subsequently flowing a substantially equal amount of charge through said electrical current path in the opposite direction to form one cycle of charge flow, and d. determining the time required to form one cycle of charge flow.
Claim 2
Independent Claim
89 words
The method of indicating electrical conductance between two points of animal tissue which form an electrical current path comprising the steps of: a. making electrical contact to said animal tissue at each of said two points, b. flowing a predetermined amount of charge through said electrical current path in one direction, c. subsequently flowing a substantially equal amount of charge through said electrical current path in the opposite direction to form one cycle of charge flow, and d. determining the time required to form one cycle of charge flow.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the step of determining comprises activating an audio frequency sound in response to the alternating flow of electrical charge.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the step of determining comprises activating a meter in response to the frequency of said alternating flow of electrical charge.
Claim 5
Dependent Claim
71 words
The method of claim 1 wherein the steps of flowing charge in said one direction and subsequently in said opposite direction comprise the steps of establishing a potential difference across said animal tissue, measuring the charge flow through said current path in one direction, reversing the polarity of said potential difference after a predetermined amount of charge flow, and measuring the charge flow through said current path in the opposite direction.
Claim 6
Dependent Claim
120 words
The method of claim 1 wherein the steps of flowing charge in said one direction and subsequently in said opposite direction comprise the steps of alternately charging an electrical capacitor to a first and a second predetermined voltage levels with an electrical current, passing the said electrical current through said electrical current path, deriving said electrical current from a voltage source which can be switched to a first and a second voltage value, and switching said voltage source from the first value to the second value when the capacitor reaches the said first predetermined voltage level, and switching said voltage source from the said second value to the first value when the capacitor reaches the said second predetermined voltage level.
Claim 7
Dependent Claim
55 words
The method of claim 1 wherein the step of making electrical contact to said animal tissue at each of said two points comprises making contact to the first point with a fixed electrode, and making contact to the second point with a movable electrode having a contacting area less thaN that of the fixed electrode.
Claim 8
Dependent Claim
88 words
Apparatus for indicating electrical conductance between two points of animal tissue which form an electrical current path comprising: a. means for making electrical contact to said animal tissue at each of said two points, b. means for flowing a predetermined amount of charge through said electrical current path in one direction and for subsequently flowing a substantially equal amount of charge through said electrical current path in the opposite direction to form one cycle of charge flow, and c. indicator means responsive to said cycle at charge flow.
Claim 9
Dependent Claim
88 words
Apparatus for indicating electrical conductance between two points of animal tissue which form an electrical current path comprising: a. means for making electrical contact to said animal tissue at each of said two points, b. means for flowing a predetermined amount of charge through said electrical current path in one direction and for subsequently flowing a substantially equal amount of charge through said electrical current path in the opposite direction to form one cycle of charge flow, and c. indicator means responsive to said cycle at charge flow.
Claim 10
Dependent Claim
26 words
The apparatus of claim 7 wherein said indicator means comprises means for activating an audio frequency sound in response to the alternating flow of electrical charge.
Claim 11
Dependent Claim
27 words
The apparatus of claim 7 wherein said indicator means comprises means for activating a meter in response to the frequency of said alternating flow of electrical charge.
Claim 12
Dependent Claim
98 words
The apparatus of claim 7 wherein the means for flowing the charge in opposite directions comprises a voltage source, a capacitor, and circuit means for passing the current derived from said voltage source through said electrical current path and said capacitor, and means for switching said voltage source from the first voltage value to the second voltage value when the voltage across the capacitor reaches a first predetermined voltage level and for switching said voltage source from the second voltage value to the first voltage value when the voltage across the capacitor reaches a second predetermined voltage level.
Claim 13
Dependent Claim
51 words
The apparatus of claim 7 wherein the means for making electrical contact comprises a first and second electrode means, said first electrode means fixable to the animal tissue, said second electrode means being movable over the surface of the animal tissue and having a contacting area less than the fixed electrode.
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) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |