US5797854A
Expired / Lapsed
US
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Method and apparatus for testing and measuring current perception threshold and motor nerve junction performance
Assignee: Individual
•
Filing: 1995-08-01
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Granted: 1998-08-25
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Expires: 2015-08-01
Abstract
Abstract A system is provided for stimulating and measuring performance of nerves which utilizes a novel system of electrodes. A large moistened absorbent pad-type electrode is used to provide one electrical contact with the body. A small moistened absorbent pad-type electrode in a handheld pencil-like configuration is used to provide a second, more targeted electrical contact with the body. By placing the large electrode along or near the spine, the pencil-like electrode may be used to excite and measure nerves on opposite sides of the body. In this manner, the electrical contact made by the large electrode is a constant during the measurement, both as to distance from the tested nerve site, and as to electrical conduction to the body. This arrangement provides more reliable and repeatable measurements. It also avoids patient discomfort associated with needle-like probes, tape-on probes, and other probes which involve discomfort. In another aspect of the invention, a galvanic skin response measurement system is incorporated into the nerve performance measurement system and is used to determine threshold nerve sensing events, rather than relying upon oral input from the patient. In this way, actual events are detected which do not rely for their accuracy upon the truthfulness of the patient. In another aspect of the present invention, the 2000 Hz signal used to stimulate the type A-Beta nerves is amplitude modulated with an adjustable sine wave signal in the range of about 5 Hz to about 700 Hz in order to obtain increased patient sensitivity to the combined signal.
Inventors
- 👤 James L. Hedgecock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:09
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/388; A61N; A61N1/00; A61N1/02; A61N1/04; A61N1/05; A61N1/0502; A61N1/18; A61N1/32; A61N1/36; A61N1/36014; A61N1/3603; A61N1/36034
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
160 words
An apparatus for testing and measuring current perception threshold in selected nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a current-limited electrical signal; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first electrode comprising an absorbent pad of at least about 4 square inches in surface area and capable of being moistened to enhance electrical contact with the skin of the patient; a single second electrode adapted to be placed at a distance from said first electrode; the apparatus adapted to cause said electrical signal to pass through said first electrode, the selected nerve fiber groups of the patient, and said second electrode; threshold detection means for detecting a threshold current magnitude at which the selected nerve fiber groups of the patient first perceive said electrical signal; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 2
Independent Claim
160 words
An apparatus for testing and measuring current perception threshold in selected nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a current-limited electrical signal; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first electrode comprising an absorbent pad of at least about 4 square inches in surface area and capable of being moistened to enhance electrical contact with the skin of the patient; a single second electrode adapted to be placed at a distance from said first electrode; the apparatus adapted to cause said electrical signal to pass through said first electrode, the selected nerve fiber groups of the patient, and said second electrode; threshold detection means for detecting a threshold current magnitude at which the selected nerve fiber groups of the patient first perceive said electrical signal; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 3
Dependent Claim
32 words
An apparatus according to claim 1 wherein said second electrode is a handheld electrode including a fibrous tip which may be moistened to enhance electrical contact with the skin of the patient.
Claim 4
Dependent Claim
14 words
An apparatus according to claim 1 wherein said electrical signal is a sine wave.
Claim 5
Dependent Claim
20 words
An apparatus according to claim 1 wherein said electrical signal is a sine wave amplitude modulated by another sine wave.
Claim 6
Independent Claim
159 words
An apparatus for testing and measuring current perception threshold in selected type A-Beta nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a repeating current-limited electrical signal of approximately 2000 Hz in frequency; means for amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first electrode; a single second electrode; the apparatus adapted to cause said electrical signal to pass through said first electrode, the selected type A-Beta nerve fiber groups of the patient, and said second electrode; threshold detection means for detecting a threshold current magnitude at which the selected type A-Beta nerve fiber groups of the patient first perceive said electrical signal; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 7
Independent Claim
159 words
An apparatus for testing and measuring current perception threshold in selected type A-Beta nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a repeating current-limited electrical signal of approximately 2000 Hz in frequency; means for amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first electrode; a single second electrode; the apparatus adapted to cause said electrical signal to pass through said first electrode, the selected type A-Beta nerve fiber groups of the patient, and said second electrode; threshold detection means for detecting a threshold current magnitude at which the selected type A-Beta nerve fiber groups of the patient first perceive said electrical signal; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 8
Dependent Claim
14 words
An apparatus according to claim 5 wherein said modulating signal is a sine wave.
Claim 9
Dependent Claim
24 words
An apparatus according to claim 5 wherein said first electrode is an absorbent pad of at least about 4 square inches in surface area.
Claim 10
Dependent Claim
24 words
An apparatus according to claim 6 wherein said first electrode is an absorbent pad of at least about 4 square inches in surface area.
Claim 11
Dependent Claim
32 words
An apparatus according to claim 7 wherein said second electrode is a handheld electrode including a fibrous tip which may be moistened to enhance electrical contact with the skin of the patient.
Claim 12
Dependent Claim
32 words
An apparatus according to claim 8 wherein said second electrode is a handheld electrode including a fibrous tip which may be moistened to enhance electrical contact with the skin of the patient.
Claim 13
Independent Claim
177 words
An apparatus for testing and measuring current perception threshold in selected nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a repeating current-limited electrical signal having a selected frequency in the range of about 5 Hz to about 2000 Hz; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first and a single second current perception threshold electrode; a first and a second separate galvanic skin response electrode; the apparatus adapted to cause said electrical signal to pass through said first current perception threshold electrode, the selected nerve fiber groups of the patient, and said second current perception threshold electrode; threshold detection means for detecting a threshold current magnitude at which the selected nerve fiber groups of the patient first perceive said electric signal, said threshold detection means responsive to a change in patient skin resistance measured between said first and second galvanic skin response electrodes; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 14
Independent Claim
177 words
An apparatus for testing and measuring current perception threshold in selected nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a repeating current-limited electrical signal having a selected frequency in the range of about 5 Hz to about 2000 Hz; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first and a single second current perception threshold electrode; a first and a second separate galvanic skin response electrode; the apparatus adapted to cause said electrical signal to pass through said first current perception threshold electrode, the selected nerve fiber groups of the patient, and said second current perception threshold electrode; threshold detection means for detecting a threshold current magnitude at which the selected nerve fiber groups of the patient first perceive said electric signal, said threshold detection means responsive to a change in patient skin resistance measured between said first and second galvanic skin response electrodes; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 15
Independent Claim
201 words
An apparatus for testing and measuring current perception threshold in selected nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a repeating current-limited electrical signal; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first current perception threshold electrode comprising an absorbent pad of at least 4 square inches in surface area; a single second current perception threshold electrode adapted to be placed at a distance from said first current perception threshold electrode; a first and a second galvanic skin response electrode separate from said first and second current perception threshold electrodes; the apparatus adapted to cause said electrical signal to pass through said first current perception threshold electrode, the selected nerve fiber groups of the patient, and said second current perception threshold electrode; threshold detection means for detecting a threshold current magnitude at which the selected nerve fiber groups of the patient first perceive said electric signal, said threshold detection means responsive to a change in patient skin resistance measured between said first and second galvanic skin response electrodes; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 16
Independent Claim
201 words
An apparatus for testing and measuring current perception threshold in selected nerve fiber groups of a patient, said apparatus comprising: a waveform generator for generating a repeating current-limited electrical signal; means for varying an electrical current magnitude of said electrical signal among a plurality of values; a single first current perception threshold electrode comprising an absorbent pad of at least 4 square inches in surface area; a single second current perception threshold electrode adapted to be placed at a distance from said first current perception threshold electrode; a first and a second galvanic skin response electrode separate from said first and second current perception threshold electrodes; the apparatus adapted to cause said electrical signal to pass through said first current perception threshold electrode, the selected nerve fiber groups of the patient, and said second current perception threshold electrode; threshold detection means for detecting a threshold current magnitude at which the selected nerve fiber groups of the patient first perceive said electric signal, said threshold detection means responsive to a change in patient skin resistance measured between said first and second galvanic skin response electrodes; and means for displaying an indication of said electrical current magnitude corresponding to the current perception threshold.
Claim 17
Dependent Claim
32 words
An apparatus according to claim 11 wherein said second electrode is a handheld electrode including a fibrous tip which may be moistened to enhance electrical contact with the skin of the patient.
Claim 18
Dependent Claim
32 words
An apparatus according to claim 12 wherein said second electrode is a handheld electrode including a fibrous tip which may be moistened to enhance electrical contact with the skin of the patient.
Claim 19
Dependent Claim
34 words
An apparatus according to claim 11 further comprising means for amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz.
Claim 20
Dependent Claim
34 words
An apparatus according to claim 12 further comprising means for amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz.
Claim 21
Independent Claim
168 words
A method for measuring a current perception threshold in a selected nerve fiber group of a patient, said method comprising: (a) applying a single first electrode comprising an absorbent pad of at least about 4 square inches in surface area to the back of the patient along the patient's spine; (b) moistening said first electrode; (c) applying a single second electrode to a first selected point on the skin of the patient, said point selected so as to measure the selected nerve fiber group; (d) generating a repeating current-limited electrical signal with a waveform generator; (e) causing said electrical signal to pass through said first electrode, the selected nerve fiber group, and said second electrode; (f) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal; (g) displaying said current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal.
Claim 22
Independent Claim
168 words
A method for measuring a current perception threshold in a selected nerve fiber group of a patient, said method comprising: (a) applying a single first electrode comprising an absorbent pad of at least about 4 square inches in surface area to the back of the patient along the patient's spine; (b) moistening said first electrode; (c) applying a single second electrode to a first selected point on the skin of the patient, said point selected so as to measure the selected nerve fiber group; (d) generating a repeating current-limited electrical signal with a waveform generator; (e) causing said electrical signal to pass through said first electrode, the selected nerve fiber group, and said second electrode; (f) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal; (g) displaying said current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal.
Claim 23
Independent Claim
206 words
A method for measuring a current perception threshold in a selected type A-Beta nerve fiber group of a patient, said method comprising: (a) applying a single first electrode comprising an absorbent pad of at least about 4 square inches in surface area to the back of the patient along the patient's spine; (b) moistening said first electrode; (c) applying a single second electrode to a first selected point on the skin of the patient, said point selected so as to measure the selected type A-Beta nerve fiber group; (d) generating a repeating current-limited electrical signal with a waveform generator having a frequency of approximately 2000 Hz; (e) amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz; (f) causing said electrical signal to pass through said first electrode, the selected type A-Beta nerve fiber group, and said second electrode; (g) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal; (h) displaying said current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal.
Claim 24
Independent Claim
206 words
A method for measuring a current perception threshold in a selected type A-Beta nerve fiber group of a patient, said method comprising: (a) applying a single first electrode comprising an absorbent pad of at least about 4 square inches in surface area to the back of the patient along the patient's spine; (b) moistening said first electrode; (c) applying a single second electrode to a first selected point on the skin of the patient, said point selected so as to measure the selected type A-Beta nerve fiber group; (d) generating a repeating current-limited electrical signal with a waveform generator having a frequency of approximately 2000 Hz; (e) amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz; (f) causing said electrical signal to pass through said first electrode, the selected type A-Beta nerve fiber group, and said second electrode; (g) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal; (h) displaying said current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal.
Claim 25
Independent Claim
209 words
A method for measuring a current perception threshold in a selected nerve fiber group of a patient, said method comprising: (a) applying a single first electrode to the patient; (b) applying a single second electrode to a first selected point on the skin of the patient, said point selected so as to measure the selected nerve fiber group; (c) generating a repeating current-limited electrical signal with a waveform generator having a selected frequency in the range of about 5 Hz to about 2000 Hz; (d) causing said electrical signal to pass through said first electrode, the selected nerve fiber group, and said second electrode; (e) applying a separate pair of galvanic skin resistance electrodes to the skin of the patient and monitoring skin resistance values measured by said resistance electrodes; (f) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the selected nerve fiber group of the patient first achieves perception of said electrical signal, said perception determined to have occurred at a point in time when said skin resistance values change by more than a predetermined amount; and (g) displaying said current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal.
Claim 26
Independent Claim
209 words
A method for measuring a current perception threshold in a selected nerve fiber group of a patient, said method comprising: (a) applying a single first electrode to the patient; (b) applying a single second electrode to a first selected point on the skin of the patient, said point selected so as to measure the selected nerve fiber group; (c) generating a repeating current-limited electrical signal with a waveform generator having a selected frequency in the range of about 5 Hz to about 2000 Hz; (d) causing said electrical signal to pass through said first electrode, the selected nerve fiber group, and said second electrode; (e) applying a separate pair of galvanic skin resistance electrodes to the skin of the patient and monitoring skin resistance values measured by said resistance electrodes; (f) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the selected nerve fiber group of the patient first achieves perception of said electrical signal, said perception determined to have occurred at a point in time when said skin resistance values change by more than a predetermined amount; and (g) displaying said current magnitude at which the selected nerve fiber group of the patient first perceives said electrical signal.
Claim 27
Dependent Claim
152 words
A method according to claim 17 further comprising the steps of: (h) applying said single second electrode to a second selected point on the skin of the patient, said second selected point selected so as to be at an opposite point of the patient's body from said first selected point, so as to measure a nerve fiber group opposite said selected nerve fiber group; (i) generating a repeating current-limited electrical signal with a waveform generator; (j) causing said electrical signal to pass through said first electrode, the opposite selected nerve fiber group, and said second electrode; (k) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the opposite selected nerve fiber group of the patient first perceives said electrical signal; and (l) displaying said current magnitude at which the opposite selected nerve fiber group of the patient first perceives said electrical signal.
Claim 28
Dependent Claim
189 words
A method according to claim 18 further comprising the steps of: (i) applying said single second electrode to a second selected point on the skin of the patient, said second selected point selected so as to be at an opposite point of the body from said first selected point, so as to measure a type A-Beta nerve fiber group opposite said selected type A-Beta nerve fiber group; (j) generating a repeating current-limited electrical signal with a waveform generator having a frequency of approximately 2000 Hz; (k) amplitude modulating said electrical signal with a modulating signal having a frequency adjustable in the range of about 5 Hz to about 700 Hz; (l) causing said electrical signal to pass through said first electrode, the opposite selected type A-Beta nerve fiber group, and said second electrode; (m) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the opposite selected nerve fiber group of the patient first perceives said electrical signal; and (n) displaying said current magnitude at which the opposite selected nerve fiber group of the patient first perceives said electrical signal.
Claim 29
Dependent Claim
242 words
A method according to claim 19 wherein said first electrode is applied to the back of the patient along the patient's spine, said method further comprising the steps of: (h) applying said single second electrode to a second selected point on the skin of the patient, said second selected point selected so as to be at an opposite point of the body from said first selected point, said second point selected so as to measure current perception threshold in a nerve fiber group opposite said selected nerve fiber group; (i) generating a repeating current-limited electrical signal with a waveform generator having a selected frequency in the range of about 5 Hz to about 2000 Hz; (j) causing said electrical signal to pass through said first electrode, the opposite selected nerve fiber group, and said second electrode; (k) applying a pair of galvanic skin resistance electrodes to the skin of the patient and monitoring skin resistance values measured by said resistance electrodes; (l) adjusting the current of said electrical signal among a plurality of values and detecting a current magnitude at which the opposite selected nerve fiber group of the patient first achieves perception of said electrical signal, said perception determined to have occurred at a point in time when said skin resistance values change by more than a predetermined amount; and (m) displaying said current magnitude at which the opposite selected nerve fiber group of the patient first perceives said electrical signal.
References Cited (Backward Citations)
US3830226A
Cited
US4099519A
Cited
US4317457A
Cited
US4305402A
Cited
US4503863A
Cited
US4387723A
Cited
US4570640A
Cited
US4632117A
Cited
US4541432A
Cited
US4510939A
Cited
US4595018A
Cited
US4515168A
Cited
US4582063A
Cited
US4693254A
Cited
US4590949A
Cited
US4640286A
Cited
US4803988A
Cited
US4616660A
Cited
US4765343A
Cited
US4763656A
Cited
US4586504A
Cited
USD297168S
Cited
US4723152A
Cited
US4817628A
Cited
USD296470S
Cited
US4892105A
Cited
US4932405A
Cited
USD299746S
Cited
US4940060A
Cited
US4759377A
Cited
US4759368A
Cited
USD302302S
Cited
USD302303S
Cited
US4813418A
Cited
USD303430S
Cited
US4803986A
Cited
US4926865A
Cited
US4848357A
Cited
US5293876A
Cited
US4957980A
Cited
US4949721A
Cited
USD319881S
Cited
US4989605A
Cited
US4962766A
Cited
USD323561S
Cited
USD324106S
Cited
US4986828A
Cited
US5363859A
Cited
US5046506A
Cited
US5291883A
Cited
US5020542A
Cited
US5143081A
Cited
US5131401A
Cited
US5092344A
Cited
US5388587A
Cited
US5313956A
Cited
US5255677A
Cited
US5203330A
Cited
US5522386A
Cited
US5178145A
Cited
US5350414A
Cited
US5284153A
Cited
US5375594A
Cited
US5327902A
Cited
US5333618A
Cited
US5487756A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-24 | 2002-02-23 | 2002-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-24 | 2006-02-23 | 2006-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-24 | 2010-02-23 | 2010-08-25 | $7700.00 | Window Closed / Lapsed |