US5448997A
Expired / Lapsed
US
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Heart pacing pulse detection system
Assignee: DUTHLER REED A
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Filing: 1993-10-15
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Granted: 1995-09-12
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Expires: 2013-10-15
Abstract
Abstract A system including a process for enhancing detection of a pacing artifact in a patient having artificially paced myocardial contractions. The detection is accomplished by sensing seven EKG leads. Each lead provides a view of the heart from a different angle. The process relies on differentially amplifying the sensed pulses separately and passing the pulses through a filter. An algorithm is utilized to detect the noise level and the pacing artifact amplitude, and automatically select a proper trigger level. False pacing artifacts are eliminated by use of the software qualification. The principal is that if the hardware differentiator produces a signal due to noise or a pacing artifact, an interrupt is generated.
Inventors
- 👤 John M. Kruse
- 👤 Cameron J. Kaszas
- 👤 C. Gary Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:48
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/37; A61N1/3702
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
189 words
A heart pacing pulse detection system comprising: (a) means for inputing ECG signals; (b) a digital signal processor; (c) a multiplexer including a plurality of cardiac pacing artifact channel lines coupled to said inputting means and including select lines coupled to said digital signal processor; (d) a signal amplifier connected to said multiplexer and including a gain select line coupled to said digital signal processor; (e) a differentiator coupled to said signal amplifier; (f) a filter connected to said differentiator; (g) a bipolar comparator and signal squarer connected to said filter; (h) a programmable positive voltage reference and a programmable negative voltage reference connected between said bipolar comparator and said signal squarer and said select lines from said digital signal processor; (i) an optical isolator connected to said bipolar comparator and said signal squarer; (j) an inverter connected to said optical isolator and outputting an interrupt pulse to said digital signal processor; and (k) a state machine including a reset line from said digital signal processor and interval timer connected to said optical isolator and outputting data representative of a cardiac pacing pulse width to said digital signal processor.
Claim 2
Dependent Claim
189 words
A heart pacing pulse detection system comprising: (a) means for inputing ECG signals; (b) a digital signal processor; (c) a multiplexer including a plurality of cardiac pacing artifact channel lines coupled to said inputting means and including select lines coupled to said digital signal processor; (d) a signal amplifier connected to said multiplexer and including a gain select line coupled to said digital signal processor; (e) a differentiator coupled to said signal amplifier; (f) a filter connected to said differentiator; (g) a bipolar comparator and signal squarer connected to said filter; (h) a programmable positive voltage reference and a programmable negative voltage reference connected between said bipolar comparator and said signal squarer and said select lines from said digital signal processor; (i) an optical isolator connected to said bipolar comparator and said signal squarer; (j) an inverter connected to said optical isolator and outputting an interrupt pulse to said digital signal processor; and (k) a state machine including a reset line from said digital signal processor and interval timer connected to said optical isolator and outputting data representative of a cardiac pacing pulse width to said digital signal processor.
Claim 3
Dependent Claim
11 words
The system of claim 1 wherein said multiplexer is 8 channels.
Claim 4
Dependent Claim
12 words
The system of claim 1 wherein said differentiator is about 30 kHZ.
Claim 5
Dependent Claim
13 words
The system of claim 3 wherein said differentiator is a high pass filter.
Claim 6
Dependent Claim
13 words
The system of claim 1 wherein said filter is a low pass filter.
Claim 7
Dependent Claim
17 words
The system of claim 5 wherein a pole of said low pass filter is about 100 kHZ.
Claim 8
Dependent Claim
35 words
The system of claim 1 wherein said positive voltage reference and said negative voltage reference generate positive and negative reference voltages respectively and wherein said digital signal processor selects a value for said reference voltages.
Claim 9
Dependent Claim
15 words
The system of claim 1 wherein said optical isolator is a high voltage optical isolator.
Claim 10
Dependent Claim
16 words
The system of claim 1 wherein said low pass filter includes a gain of about 2.
Claim 11
Dependent Claim
16 words
The system of claim 1 wherein said bipolar comparator and signal squarer is a voltage comparator.
Claim 12
Dependent Claim
98 words
A heart pacing pulse detection system comprising: (a) a plurality of ECG leads; (b) an analog detector connected to said plurality of ECG leads; and (c) a signal processor connected to said analog detector, said signal processor comprising: (i) a timer control/interrupt handler connected to said analog detector; (ii) a signal screener having an output and connected to said timer control/interrupt handler; (iii) an event counter filter connected to said timer control/interrupt handler and said output of said signal screener; and (iv) an automatic detection level adjustment circuit connected between said event counter filter and said analog detector.
Claim 13
Dependent Claim
98 words
A heart pacing pulse detection system comprising: (a) a plurality of ECG leads; (b) an analog detector connected to said plurality of ECG leads; and (c) a signal processor connected to said analog detector, said signal processor comprising: (i) a timer control/interrupt handler connected to said analog detector; (ii) a signal screener having an output and connected to said timer control/interrupt handler; (iii) an event counter filter connected to said timer control/interrupt handler and said output of said signal screener; and (iv) an automatic detection level adjustment circuit connected between said event counter filter and said analog detector.
Claim 14
Dependent Claim
23 words
The system of claim 11 further comprising means for selecting which of said plurality of ECG leads are coupled to said analog detector.
Claim 15
Dependent Claim
108 words
A process for heart pacing pulse detection comprising the steps of (a) monitoring a patient's skin surface potentials; (b) passing signals representative of said skin surface potentials through a differentiator and a low pass filter to generate filtered output signals; (c) comparing said filtered output signals with predetermined programmable reference signals to generate interrupt signals; (d) counting and filtering said interrupt signals to generate filtered counts of events, wherein said events are possible pacing artifacts; and (e) adjusting a predetermined detection level with respect to said filtered counts of events and adjusting said programmable reference signals in response to said adjusted predetermined detection level to detect pacing artifacts.
Claim 16
Dependent Claim
108 words
A process for heart pacing pulse detection comprising the steps of (a) monitoring a patient's skin surface potentials; (b) passing signals representative of said skin surface potentials through a differentiator and a low pass filter to generate filtered output signals; (c) comparing said filtered output signals with predetermined programmable reference signals to generate interrupt signals; (d) counting and filtering said interrupt signals to generate filtered counts of events, wherein said events are possible pacing artifacts; and (e) adjusting a predetermined detection level with respect to said filtered counts of events and adjusting said programmable reference signals in response to said adjusted predetermined detection level to detect pacing artifacts.
Claim 17
Dependent Claim
30 words
The process of claim 13 wherein said step of counting and filtering said interrupt signals comprises counting said filtered counts of events over 100 ms and 5000 ms time windows.
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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) | 1998-09-11 | 1999-03-13 | 1999-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-09-11 | 2003-03-13 | 2003-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-09-11 | 2007-03-13 | 2007-09-12 | $7700.00 | Window Closed / Lapsed |