Biological signals are electrical or magnetic signals generated by some biological activity in the human body. Biological signals have widely different sources, like the ECG originating from the hart or the EEG generated by the brain, making them very heterogeneous. Some have high amplitude and frequency where the clinical importance lies typically in the morphology of a few simultaneously collected signals, preferably analyzed in the frequency or time domain. Or it could be hundreds of signals with extremely small amplitudes where the clinical information is of a spatial nature calling for localization and 3D reconstruction. Our long clinical experience within this field has given us ample opportunities getting acquainted with the whole spectrum of biological signals.
The Clinical Environment
Signal analysis is one of our core competencies. We are well acquainted with the different signal analysis techniques and have long experience in digital filtering, wavelet analysis, artefact rejection etc. But it is in the real life clinical environment that signal analysis becomes a true challenge. Trying to analyze a nerve conduction signal in the operation room while the surgeon is using a cautery knife is where our skills come to their right. We know how important it is for the clinicians that we treat the signals with outmost care, using nondestructive filtering and always with the possibility to display the original non manipulated raw signal. And doing this on-line in real time with limited computational resources is just another obstacle that we have learned to overcome.
Throughout the years we have been able to collect an extensive library holding different types of biological signals. This is a crucial asset both when developing new types of analysis and validating changes to existing algorithms ensuring correct analysis results and backwards compatibility.