Fourier analysis of impedance rheography for peripheral arterial occlusive disease.
This study identified those harmonics from the frequency spectrum of electrical impedance rheographic signals that discriminate between patients with and without peripheral arterial occlusive disease (PAOD). Ninety-four patients with suspected PAOD were evaluated by impedance rheography and ankle-arm blood pressure index. The leg with the lower ankle-arm index was used in the analysis and a haemodynamically relevant PAOD was assumed at an ankle-arm index lower than 0.85. The frequency spectrum of the impedance signals of the shank was calculated by means of a fast Fourier transformation algorithm. The first ten harmonics were used as independent variables in a stepwise logistic regression analysis to evaluate the dependent variable PAOD. In the regression analysis only the third harmonic was accepted ( P<0.0001). The correct classification of the patients was 90%. In conclusion, by means of Fourier analysis of impedance rheographic signals, a high accuracy in the diagnosis of PAOD can be achieved.
Schuhfried
Othmar
O
Department of Physical Medicine and Rehabilitation, University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria. othmar.schuhfried@univie.ac.at
Wiesinger
Günther
G
Kollmitzer
Josef
J
Mittermaier
Christian
C
Quittan
Michael
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D017097:Electric Impedance; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010992:Plethysmography, Impedance / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography