Improved analysis of Cl- patch clamp signals using discrete wavelet approximations

The discrete wavelet transform (DWT) is applied to Cl^- channel patch clamp signals for improved analysis of channel current statistics. The method is shown to be particularly useful with signals that are difficult to analyze with currently used histogram-based methods. The DWT is used as a preprocessing tool before computing the signals´ amplitude histograms and estimating the current statistics. Six signals are analyzed using various mother wavelets. The DWT is used to extract approximations of the signals at varying scales. The channel current statistics are estimated for the original signal, as well as the wavelet approximations. The estimates are compared to the “true” statistical values. When using the wavelet approximations at the optimum scale, the percent error in the estimated current mean is typically reduced by one to two orders of magnitude