Some new researches for non-invasive diagnostic applications, by detecting local thermal gradients on internal tissues, seeking a very-early detection of some types of cancer are a promising investigation way with high medical interest. The signals processing methods and algorithms, in which those are based, must be robust enough, even when the echoresponses contain moderated levels of coherent noise.
In this paper, the influences of some levels of induced noises, including those of the coherent type, are analyzed in time & frequency domains. The power spectrum shifts on overtones are also investigated. So, an analysis of time & frequency curves alterations and of finally estimated thermal distribution is made, for distinct synthetic noisy multi-pulse waveforms, similar to those appearing in real echo-acquisitions.
Finally, some behaviors in waveforms and power spectra are analyzed from complex noisy echo-waveforms containing many ultrasonic pulses overlapping among them.
