Validity of wavelet transforms for analysis of video head impulse test (vHIT) results.

Abstract

To explore the applicability of discrete wavelet transforms in the analysis of vHIT responses. Discrete wavelet transform was applied to vHIT responses and a new method for calculating aVOR gain was developed. A prospective study was performed with two groups of normal (N=10) and altered (N=19) gain values; HIMP and SHIMP vHIT protocols were performed on both groups. To evaluate the gain values obtained, Intraclass Correlation Index, Pearson's correlation, linear regression, and t test were performed. Intraclass correlation indexes of 0.97 and 0.99 were determined for HIMP and SHIMP procedures performed on the proposed and standard gain calculation method. A significant difference of - 0.06±0.07 (p<0.001) was found between gain calculation methods for HIMP protocol. Significant differences were found (p<0.001) between normal and altered groups for all gain calculation methods. Discrete wavelet transforms were successfully applied to measure head impulse test responses. Gain values obtained with this method appear to be valid and in concordance with gain values obtained with standard calculation method. However, a slight but significant difference was observed when this method was applied to tests obtained with HIMP.