US5454377A
Expired / Lapsed
US
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Method for measuring the myocardial electrical impedance spectrum
Assignee: The Ohio State University
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Filing: 1993-10-08
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Granted: 1995-10-03
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Expires: 2013-10-08
Abstract
Abstract A method for measuring the complex impedance spectrum of a portion of the myocardium by placing two electrodes on a portion of the myocardium and applying a current pulse to the electrodes to generate a voltage response between the electrodes. Both the current pulse and voltage response are sampled and digitized and then a Fast fourier transform is taken of both the current pulse and the voltage response to obtain a complex current pulse spectrum and a complex voltage response spectrum. Next, the complex voltage response spectrum is divided by the complex current pulse spectrum to obtain the complex impedance spectrum.
Inventors
- 👤 Roger R. Dzwonczyk
- 👤 Alan Y. Liu
- 👤 Alan W. Hartzler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:05
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/41; A61B5/413; A61B5/05; A61B5/053; A61B5/0535; A61B5/72; A61B5/7235; A61B5/7253; A61B5/7257
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
A method for measuring a complex impedance spectrum of a portion of myocardium between two electrodes, the method comprising: (a) applying a current pulse to the electrodes to generate a voltage response between the electrodes; (b) sampling and digitizing both the applied current pulse and the voltage response; (c) performing a fast Fourier transform upon both the digitized current pulse and the digitized voltage response to obtain a complex current pulse spectrum and a complex voltage response spectrum; (d) dividing the complex voltage response component for each frequency in the voltage response spectrum by the complex current pulse component for each corresponding frequency in the current pulse spectrum to obtain the complex impedance spectrum; and (e) displaying complex impedance spectrum data for analysis for a physician.
Claim 2
Independent Claim
126 words
A method for measuring a complex impedance spectrum of a portion of myocardium between two electrodes, the method comprising: (a) applying a current pulse to the electrodes to generate a voltage response between the electrodes; (b) sampling and digitizing both the applied current pulse and the voltage response; (c) performing a fast Fourier transform upon both the digitized current pulse and the digitized voltage response to obtain a complex current pulse spectrum and a complex voltage response spectrum; (d) dividing the complex voltage response component for each frequency in the voltage response spectrum by the complex current pulse component for each corresponding frequency in the current pulse spectrum to obtain the complex impedance spectrum; and (e) displaying complex impedance spectrum data for analysis for a physician.
Claim 3
Dependent Claim
35 words
A method in accordance with claim 1 wherein said displaying step further comprises displaying the absolute value of a complex magnitude component for each of a plurality of frequency components of the complex impedance spectrum.
Claim 4
Dependent Claim
34 words
A method in accordance with claim 2 including displaying the absolute values of the magnitude component for each of a plurality of frequency components of the complex impedance spectrum as a function of frequency.
Claim 5
Dependent Claim
31 words
A method in accordance with claim 1 wherein said displaying step further comprises displaying a complex phase angle component value for a plurality of frequency components of the complex impedance spectrum.
Claim 6
Dependent Claim
23 words
A method in accordance with claim 1 wherein the current pulse has approximately a 10 microamp amplitude and approximately a 0.15 millisecond duration.
Claim 7
Dependent Claim
35 words
A method in accordance with claim 5 and further comprising after each current pulse, applying a second, depolarizing pulse having an amplitude and duration substantially equal to the preceding current pulse, but in opposite polarity.
References Cited (Backward Citations)
US4805621A
Cited
US4823797A
Cited
US4870967A
Cited
US5051352A
Cited
US4899750A
Cited
US5203344A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |