Applications of Wavelet Transforms in Biomedical Optoacoustics

We discuss the utility of wavelet transform methods in signal processing in general, and in particular, demonstrate the technique in optoacoustic applications. In several optoacoustic experiments with different samples, we have successfully enhanced the signal to noise ratios. Wavelet transforms optimize resolution by utilizing a tailored, variable time-window in different frequency regions. The technique\u27s great advantage lies in the fact that the wavelet transform adds some redundancy to the original signal, and some desired features can be enhanced in the transformed space. In addition, proper choice of the basis set allows a sparse representation of the signal. Therefore, even when some components are suppressed in the transformed space, the signal itself can maintain its fidelity. This technique has great potential in biomedical optoacoustics, such as medical image processing and signal denoising. We use the wavelet transform technique to resolve acoustic echoes in the time-dilation space. White noise was removed by the wavelet shrinkage method. This processing was used to analyze several experimental results. These include optoacoustic measurements in solid samples as well as in biological tissues