Current restoration for ionic single channel based on the wavelet package transform

Ionic single-channel signal of cell membrane is a stochastic ionic current in the order of picoampere (pA). Because of the weakness of the signal, the background noise always dominates in the patch-clamp measuring. A new approach based on wavelet package algorithm is presented to reconstruct ionic currents. In the study, the scale-power distribution of the signal is obtained by the multi-resolution analysis to ionic currents using the wavelet package decomposing. Then, the signals are reconstructed by wavelet package algorithm. And after smoothing filter, the ideal ionic currents are restored from Markov sequences contaminated by noise. Experiment results have shown that this method can precisely reconstruct the ion currents under the lower signal-to-noise ratio, and has fast parameter convergence and strong anti-noise ability. Therefore, this method can be applied in the real-time processing system of patch-clamp measurement.