US4603703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for real-time detection and identification of neuroelectric signals
Assignee: BOARD OF RUSTEES OF LELAND STANFORD JUNIOR UNIVERSITY A BODY CORPORATE OF CALIFORNIA
•
Filing: 1984-04-13
•
Granted: 1986-08-05
•
Expires: 2004-04-13
Abstract
Abstract Neuroelectric signals are detected and processed by digital filtering to detect, classify and determine the relative proportions of the different types of signals eminating from muscle, nerve or brain tissue.
Inventors
- 👤 Kevin C. McGill
- 👤 Leslie J. Dorfman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:33
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/318; A61B5/346; A61B5/349; A61B5/35; A61B5/72; A61B5/7235; A61B5/7239; A61B5/7264
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
39 words
A method of real time analysis of neuroelectrophysiological signals for detecting and identifying action potentials comprising the steps of digitally filtering the signals using a low-pass differentiator and automatically detecting and identifying the recurring spikes in the filtered signal.
Claim 2
Independent Claim
39 words
A method of real time analysis of neuroelectrophysiological signals for detecting and identifying action potentials comprising the steps of digitally filtering the signals using a low-pass differentiator and automatically detecting and identifying the recurring spikes in the filtered signal.
Claim 3
Dependent Claim
36 words
A method as claimed in claim 1 wherein said identifying step includes the step of issuing a trigger pulse on one of a plurality of output lines to indicate the identity of the detected action potential.
Claim 4
Dependent Claim
34 words
A method as claimed in claim 1 wherein the step of digitally filtering the neuroelectrophysiological signal compares the filtered neuroelectrophysiological signal to an assigned threshold value, the spikes representing action potentials exceeding the threshold.
Claim 5
Dependent Claim
35 words
A method as claimed in claim 3 wherein the detecting step includes dividing the action potential signal into intervals, wherein each interval contains one of said spikes, and assigning a signature to each signal interval.
Claim 6
Dependent Claim
17 words
A method as claimed in claim 4 wherein said signal intervals are disjoint and do not overlap.
Claim 7
Dependent Claim
34 words
A method as claimed in claim 4 including the step of comparing each signal signature to a plurality of stored signatures stored as templates, and indicating the closest match between signal and template signature.
Claim 8
Dependent Claim
39 words
A method as claimed in claim 6 including the step of adapting the template indicated as the closest match to the signal signature to improve the template's signal to noise ratio and to track slow changes in signature configuration.
Claim 9
Dependent Claim
48 words
A method as claimed in claim 7 including calculating the error differential between the signal signature and the template indicated as the closest match, comparing the differential error to a stored threshold error value, and inhibiting the output if the error differential exceeds the stored error threshold level.
Claim 10
Dependent Claim
40 words
A method as claimed in claim 8 further comprising the steps of replacing the template having a stored history of the fewest previous matches with the signal signature in response to the indication of error differential exceeding the threshold value.
Claim 11
Dependent Claim
40 words
A method as claimed in claim 8 further comprising the steps of replacing the template having a stored history of the fewest previous matches with the signal signature in response to the indication of error differential exceeding the threshold value.
Claim 12
Dependent Claim
54 words
A method as claimed in claim 6 wherein each of said signal signatures and template signatures comprises an equal number of words, said process further comprising the step of aligning said spike signature for comparison with the template signatures by centering the word representing the peak value of the neuroelectrophysiological signal in said interval.
Claim 13
Dependent Claim
53 words
A method as claimed in claim 11 including the steps of initially sampling the neuroelectrophysiological signals at a rate fast enough to locate the peaks with high temporal resolution, and then decimating the samples to obtain said signal signature, keeping only the theoretically minimum number of samples needed to characterize the signal signature.
Claim 14
Dependent Claim
27 words
A method as claimed in claim 11 wherein said process further includes the step of simultaneously comparing the signal signature with a plurality of said template signatures.
Claim 15
Dependent Claim
32 words
A method as claimed in claim 13 wherein said digitally filtering step includes a low pass differentiating of the action potential signal utilizing a formula having only additive terms in the algorithm.
Claim 16
Dependent Claim
46 words
A method as claimed in claim 14 wherein said digital filtering step comprises developing a first order differential of the signal according to the formula Y.sub.t =X.sub.t+T -X.sub.t-T where X is the raw signal, Y is the filtered signal, T is the signal's Nyquist sampling interval.
Claim 17
Dependent Claim
48 words
A method as claimed in claim 15 wherein said digital filtering step comprises developing a second order differential of the signal according to the formula Y.sub.t =-X.sub.t+3T +X.sub.t+2T +X.sub.t+T -X.sub.t-T where X is the raw signal, Y is the filtered signal, T is the signal's Nyquist sampling interval.
Claim 18
Dependent Claim
28 words
A method as claimed in claim 13 including the step of adapting the template indicated as the closest match to the signal signature to reflect the actual signature.
Claim 19
Dependent Claim
48 words
A method as claimed in claim 17 including calculating the error differential between the signal signature and the template indicated as the closest match, comparing the differential error to a stored threshold error value, and inhibiting the output if the error differential exceeds the stored error threshold level.
Claim 20
Dependent Claim
54 words
A method as claimed in claim 17 wherein each of said signal signatures and template signatures comprises an equal number of words, said process further comprising the steps of aligning said spike signature for comparison with the template signature by centering the word representing the peak value of the signal in the signal signature.
Claim 21
Dependent Claim
27 words
A method as claimed in claim 19 wherein said process further includes the steps of simultaneously comparing the signal signature with a plurality of said template signatures.
Claim 22
Independent Claim
74 words
A method of real time analysis of neuroelectrophysiological signals for detecting and identifying action potentials comprising the steps of digitally filtering the signal, and detecting and identifying the recurring spikes in the filtered signal by (a) detecting as a spike each interval containing a peak whose amplitude exceeds a known threshold, (b) matching each detected spike with one of a plurality of stored spike templates, and (c) indicating the result of said matching step.
Claim 23
Independent Claim
74 words
A method of real time analysis of neuroelectrophysiological signals for detecting and identifying action potentials comprising the steps of digitally filtering the signal, and detecting and identifying the recurring spikes in the filtered signal by (a) detecting as a spike each interval containing a peak whose amplitude exceeds a known threshold, (b) matching each detected spike with one of a plurality of stored spike templates, and (c) indicating the result of said matching step.
References Cited (Backward Citations)
US3606882A
Cited
US3658055A
Cited
US3616791A
Cited
US3940692A
Cited
US4254779A
Cited
US4416288A
Cited
US4417592A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-04 | 1990-02-03 | 1990-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-04 | 1994-02-03 | 1994-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-04 | 1998-02-03 | 1998-08-05 | $7700.00 | Window Closed / Lapsed |