Ortogonalizace elektrokardiogramu velkých zvířat

Orthogonal Transforms of ECG Signals in Large Animals

report

Czech

The project dealt with a design of algorithms for orthogonal description of electrical activity of heart in horses that would be based on knowledge of signals recorded by means of the tetrahedron lead system. In the frame of the project we have designed, implemented and verified following transforms: · Levkov transform; · Gram-Schmidt orthogonalization algorithm incl. its optimised and modified versions; · conditioned transform based on the criterion of minimum root mean square error. A representative database of short time rest equine ECG signals has been collected for the algorithm verification. The database records contain 14 seconds signals recorded by means of two electrocardiographic lead systems (tetrahedron and Holmes systems) in parallel. Nowadays the database contains about 225 records. Quality of the signal sets used as an input of some transforms and also the quality of the obtained results were primarily evaluated by means of mathematical criterion of mutual signal orthogonality and the best sets of the transformed signal were further assessed by means of morphological criteria defined by veterinary cardiologists. To summarise we have found several new ways of description of electrical activity of equine heart that use signals of tetrahedron lead system as an input. The found orthogonal signals seem to have better properties than the signals recorded by means of the orthogonal Holmes system - both from the standpoint of mathematical and cardiological criteria. This fact means that we are able to give vets an opportunity to make use advantages of VCG without modification of the recording hardware.

orthogonal transforms, ECG signals, horses

HOLČÍK, J., HANÁK, J., VÁCLAVÍK, V., HRUBÝ, R., SEDLINSKÁ, M., JAHN, P.

1. 1. 2002