Analysis of optical recording stability using wavelet entropy of action potentials

A method based on wavelet entropy is presented for analysis of optically recorded action potentials to assess stability of the experiment. The action potentials are recorded using fluorescent voltage-sensitive dye di-4-ANEPPS by optical means. The acquired signals are preprocessed using averaging with filtered residue method and decomposed by continuous wavelet transform. Entropy is then computed using the wavelet coefficients. Wavelet entropy helps to detect possible amplitude and frequency changes in the signals caused by photo-bleaching.