Electrocardiogram (EKG) signals were digitized and the data analyzed with a fast Fourier transform computer pro- rain. The signals were amplified with a differential input EKG amplifier and converted to a frequency with a model 8038 function generator. The output frequency response was linear from 150 kHz to 300 kHz for an input voltage range of four volts. The frequency was recorded as a function of time Nuclear Data 2200 multichannel analyzer operated in the multiscale mode utilizing a dwell time of four cosec per channel. Digitized EKG data for 17 subjects were obtained in this manner. Previously digitized data for 29 patients were also obtained from the Public Health Service. Discrete Fourier transform analysis was performed on the data and the power spectrum was investigated for diagnostic use. The presence of ST depression in the EKG trace was found to be accompanied by a significantly larger harmonic amplitude coefficient at n = 2 and significantly lower harmonic amplitude coefficients for n = 13 through 20 than for normal EKG's. Diagnostic criteria were developed based on these power spectrum coefficients for the identification of EKG traces with abnormal ST segments.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/181083 |
| Date | January 1975 |
| Creators | McCutchan, Larry J. |
| Contributors | Ober, David R. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | vi, 54 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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