Preface

Personal health and well-being was and is important for all individuals. This includes the way people are living, what they do to stay healthy as well as a profound, well-informed diagnosis and appropriate treatment in case of disease. To achieve these goals, modern med‐ icine is provided with a large variety of tools to assess a patient's health state and collect the information required for a proper diagnosis and treatment, which is tailored to the patient's needs.

Many of these available tools use signals either generated by the human body, for example, electroencephalogram (EEG) and electrocardiogram (ECG), or by interacting with the hu‐ man body while traversing it like microwaves or reflected visible light that is recorded by a video camera. The biosignals recorded by the available and newly developed methods have to be processed to extract the information about the patient's condition and analyzed tissue and cells. This book presents some recent developments in the field of biosignal processing.

The first chapter presents a method that allows to non-intrusively assess the respiratory state of a patient just by observing his walking pattern. The proposed marker-less camerabased system can be easily integrated into clinical diagnostic process. The second chapter takes the concept of contactless assessment of the patient's health state even a step further. It uses microwave radar signals for contactless recording respiratory and cardiovascular pa‐ rameters. The advantage of microwave signals casted at the patient's body surface is that they can travel several meters and thereby even penetrate thick layers of stones and con‐ crete. Therefore, one of the applications of these methods envisioned by the authors is the monitoring of vital signs of people buried under their house after an earthquake while the rescue team is trying to remove the blocking obstacles and to prepare the necessary treat‐ ment to stabilize the subjects' condition.

Thanks to modern medicine, children who are born too early or with severe conditions have a good prognosis in surviving their first years and leading a healthy and normal life, thanks to continuously evolving and improving prenatal diagnostics. This includes the recording of the fetal ECG used to assess its cardiovascular state either through interuterine recordings or by abdominal recordings of the mother. The first method is highly invasive and therefore poses high risks for the mother and the fetus. Therefore, the authors of the third chapter propose an advanced method to record the fetal ECG (fECG) from the mother's abdomen. The proposed non-linear approach is compared with existing ones with respect to their ca‐ pability to provide additional cardiovascular parameters, such as PQ, QT, and ST time of the fetal ECG. The main challenge is to properly filter out the maternal ECG (mECG), which overlaps with the fECG, the abdominal muscles, and intestinal signals, while preserving the small signal of the fECG.

Epilepsy, which has to be considered a severe neurological condition, is characterized by recurrent seizures. In the past, it was assumed that these epileptic events are generated by a single focus and spread from there to other brain regions. Recent findings in neurological and epilepsy research indicate that a seizure is rather an abnormal activity and response of the whole network neuronal network involved. Chapter 4 presents a new network analysis approach, which uses neurophysiological data recorded prior to surgical epilepsy treatment to identify the affected brain regions and their interconnections activated during an epileptic event.

In the twentieth century, the DNA was identified to control all functions of individual cells, tissues, organs, and the whole body. Even though already available since the past century only very recently reasonably fast and accurate methods to read the DNA and analyze its structure have been developed. With this development, it became possible to use the infor‐ mation stored in the DNA for diagnostic purpose. Alterations in the structure of the DNA, for example, introduced when it is copied to generate proteins or when it is repaired after one of its strands or both broke, can severely affect the function of the cell. A large number of so-called copy number alterations (CNA) can be used to characterize cancer cells. A new method to assess and validate the CNA in the DNA of single cells is presented in Chapter 5.

This book only covers a small selection of new and advanced biosignal processing and diag‐ nostic methods. As an editor, I thank all the authors for their contributions. I also thank all researchers whose work could not be included in this book for various reasons. All your great work is an important contribution to the field of biosignal processing with respect to the development of new and improved diagnostic tools, therapies, and treatments.

> **Dr. Christoph Hintermüller** Guger Technologies OG Schiedlberg, Austria
