School of Studies Electrical Engineering, Computer Science and Mathematics (E)
Contactless detection of epilepsy
Epilepsy is a regulatory disorder of the brain. If it is not treated, it manifests itself in adults, for example, in the form of seizures or even unconsciousness. In newborns and young children, however, epilepsy is often overlooked because they do not exhibit seizures, and can therefore be fatal.
Epilepsy research is usually done only at specialized centers. This involves measuring and analyzing brain waves using an EEG (electroencephalography). This can only take place over short periods of a few hours and severely restricts the subjects during the measurements, as they are wired and not allowed to move. There is also the question of how meaningful the measurements are, since measurements are not taken under real conditions, but only under artificial conditions and over a short period of time.
Detecting danger at an early stage
For this reason, Prof. Alexander Kölpin from the Institute of High Frequency Technology (IHF) at the Technical University of Hamburg is investigating a method as part of the publicly funded BrainEpP project that enables non-contact and continuous monitoring of cardiovascular functions in young adults, infants and even premature babies. The activation of the autonomic nervous system can be inferred from the measured parameters. It is controlled by two systems with opposing effects: the sympathetic and parasympathetic nervous systems. Together they regulate vital bodily functions such as respiration, heartbeat or digestion. The fine structure of extracted cardiac signals provides information about how well this regulation takes place. Not only can epileptic seizures be estimated from this without an EEG, but incipient disturbances should also be detected before a seizure occurs. In case of such an alarm, the seizure could be suppressed with medication and the quality of life of many affected persons could be increased as well as the risk of dying in case of a seizure could be reduced. After all, it is suspected that up to 20 percent of all sudden infant deaths are related to an undiagnosed epileptic condition.
Measuring the smallest vibrations
The monitoring takes place without any contact from a short distance of up to one meter through clothing or bed covers. A so-called high-frequency interferometer is used, which transmits electromagnetic waves at minimum power, which are reflected by the body surface and received by the sensor. From this, the smallest vibrations of the body surface of only a few micrometers deflection can be recorded, as they are caused by heartbeat and breathing. This distance measurement data can be continuously collected and automatically segmented and classified using machine learning. The BrainEpP project searches the measurement data for specific markers, i.e. measurable indicators, of an impending epileptic seizure.
The contactless recording of vital data thus allows continuous monitoring of vulnerable groups of people without restricting their quality of life. Medical changes can thus be detected at an early stage, before health crises arise. This is all the more important in the case of children because epilepsy, a disease that is difficult to recognize, can lead to death if left untreated.
Project partners in the BrainEpP project, which is funded by the German Federal Ministry of Education and Research (BMBF), are the University Hospital Erlangen and the companies Geratherm Respiratory, Silicon Radar, DeMeTec and Voigtmann.
Measurement concept for non-contact epilepsy diagnostics by high-frequency interferometry