title: Fourier analysis of impedance rheography for peripheral arterial occlusive disease.
abstract: 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.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria. othmar.schuhfried@univie.ac.at
authors.forename: Othmar
authors.initials: O
authors.lastname: Schuhfried
authors.forename: Günther
authors.initials: G
authors.lastname: Wiesinger
authors.forename: Josef
authors.initials: J
authors.lastname: Kollmitzer
authors.forename: Christian
authors.initials: C
authors.lastname: Mittermaier
authors.forename: Michael
authors.initials: M
authors.lastname: Quittan
mesh_terms: 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