Acoustic Analyses of the Digital Doppler Allen Test

In this study, we aimed to perform noninvasive acoustic quantification of digital arterial Doppler sounds and to determine the possibility of evaluating digital arterial circulation using the results of acoustic assessment.

In this prospective study, we recorded the Doppler sounds of the radial and ulnar digital arteries of all digits of 25 volunteers (male, n = 10; female, n = 15) included in the study, converted these recordings into digital files, and analyzed them using a fast Fourier transform analyzer. We recorded the Doppler sound of each digital artery by means of (1) contralateral digital artery compression, (2) ipsilateral digital artery compression, and (3) no compression as a control. The analyzed parameters comprised the equivalent sound level (Leq), sound pressure difference between the maximum and minimum sound pressures (delta sound pressure), and frequency. In addition, the Doppler sounds of the contralateral and compression groups were acoustically compared with those of the control group by 2 examiners.

The contralateral compression group demonstrated a statistically lower Leq and greater delta sound pressure. In particular, the delta sound pressure had a higher sensitivity and specificity. The ipsilateral compression group had a significantly lower Leq and frequency. The Doppler sounds of the contralateral compression group resembled a staccato rhythm. The agreement rate of the kappa coefficients was high.

The patency of the digital artery is presumably high if the Doppler sound changes to a staccato rhythm upon compression of the contralateral digital artery.