US3821948A
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US
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System and method for analyzing absolute derivative signal from heartbeat
Assignee: F Hoffmann La Roche AG
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Filing: 1971-11-03
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Granted: 1974-07-02
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Expires: 1991-11-03
Abstract
Abstract An arrhythmia detection system for analyzing electrocardiographic signals comprising transforming a filtered, absolute, derivative of the electrocardiographic signals into a first integral signal defining an adaptive threshold level and depending from prior heart beat signals, transforming the electrocardiographic signals into a second integral signal representative of a heart beat virtually independent from prior heart beat signals, and comparing the levels of the first and second integral signals for generating a QRS trigger pulse. Further aspects include providing a third integral signal accentuating noise and comparing its level with the first integral signal level for inhibiting QRS trigger signals during noise occurrence.
Inventors
- 👤 E King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:54
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/318; A61B5/346; A61B5/349; A61B5/72; A61B5/7203; A61B5/7235; A61B5/7239; A61B5/7242; Y; Y10; Y10S; Y10S128/00; Y10S128/901
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
An arrhythmia detection system for analyzing an absolute derivative signal derived from a patient''s heartbeat comprising: first integrator means for generating a first signal representative of the average magnitude of an incoming absolute derivative signal over a plurality of heartbeats; second integrator means for generating a second signal representative of the magnitude of an incoming absolute derivative signal over a single heartbeat; and comparison means for comparing the magnitude of said first and second signals and generating an output representative of cardiac activity when the second signal magnitude attains a predetermined relationship with respect to the first signal magnitude.
Claim 2
Dependent Claim
99 words
An arrhythmia detection system for analyzing an absolute derivative signal derived from a patient''s heartbeat comprising: first integrator means for generating a first signal representative of the average magnitude of an incoming absolute derivative signal over a plurality of heartbeats; second integrator means for generating a second signal representative of the magnitude of an incoming absolute derivative signal over a single heartbeat; and comparison means for comparing the magnitude of said first and second signals and generating an output representative of cardiac activity when the second signal magnitude attains a predetermined relationship with respect to the first signal magnitude.
Claim 3
Dependent Claim
15 words
The system of claim 1 including narrow filter means for filtering the absolute derivative signal.
Claim 4
Dependent Claim
27 words
The system of claim 2 wherein said narrow filter means is adapted to pass an absolute derivative signal in the range from approximately 10 to 15 cycles.
Claim 5
Dependent Claim
62 words
The system of claim 1 including: third integrator means for selectively providing a third signal accentuating noise associated with said absolute derivative signal; and, second comparison means for comparing the signal magnitude of said first and third signals and generating an output signal indicative of noise when the third signal magnitude attains a predetermined relationship with respect to the first signal magnitude.
Claim 6
Dependent Claim
32 words
The system of claim 4 including: inhibiting means for inhibiting the output signal of the first comparison means indicative of cardiac activity, at least during the presence of said noise output signal.
Claim 7
Dependent Claim
25 words
The system of claim 4 including: discharge means responsive to said noise output signal for rapidly attenuating the first signal at said first integrator means.
Claim 8
Dependent Claim
81 words
The system of claim 1 wherein: said first integrator means is provided with a relatively long attack and release times so as to depend from the signal level of a prior heartbeat signal enabling said first signal to immediately adapt to a patient''s changing morphology; and said second integrator means is provided with a relatively fast attack and release times so as not to be influenced by and thereby be virtually independent of the signal level of a prior heartbeat signal.
Claim 9
Dependent Claim
29 words
The system of claim 1 wherein said second processing means is providing a decay rate to virtually attenuate to ground said second integral signal within 350 milliseconds or less.
Claim 10
Dependent Claim
30 words
The system of claim 8 wherein said first integrator means is provided a decay rate to virtually attenuate to ground the first integral signal within approximately anywhere from 3-4 seconds.
Claim 11
Independent Claim
100 words
A metHod of analyzing an absolute derivative signal derived from a patient''s heartbeat comprising the steps of: transforming the absolute derivative signal into a first integral signal representative of the average magnitude of an absolute derivative signal over a plurality of heartbeats; transforming the absolute derivative signal into a second integral signal representative of the magnitude of an absolute derivative signal over a single heartbeat; comparing the signal magnitude of said first and second integral signals to generate an output cardiac signal when the second integral signal magnitude attains a predetermined relationship with respect to the first integral signal magnitude.
Claim 12
Independent Claim
100 words
A metHod of analyzing an absolute derivative signal derived from a patient''s heartbeat comprising the steps of: transforming the absolute derivative signal into a first integral signal representative of the average magnitude of an absolute derivative signal over a plurality of heartbeats; transforming the absolute derivative signal into a second integral signal representative of the magnitude of an absolute derivative signal over a single heartbeat; comparing the signal magnitude of said first and second integral signals to generate an output cardiac signal when the second integral signal magnitude attains a predetermined relationship with respect to the first integral signal magnitude.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-01 | 1977-12-31 | 1978-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-01 | 1981-12-31 | 1982-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-01 | 1985-12-31 | 1986-07-02 | $7700.00 | Window Closed / Lapsed |