Numerical Signal Resolution Enhancement Method of ECG (NURSE-ECG) is a new diagnostic technique for cardiology developed at the Department of the Medical Physics Adam Mickiewicz University, Poznań by Professor Ryszard Krzyminiewski. The method has been developed on the basis of electrocardiography in digital recording. It offers a significantly higher resolution, and consequently, a considerable improvement of diagnostic possibilities.
digital recording of ECG signals enabled their analysis by numerical
methods, in particular allowed the use of a special computer
program enhancing the resolution of electric signals.
Fig. 1. The spectra consisting of nine lines of different initial resolution (1-3):
a) experimental spectra, b) spectra after linear signal resolution enhancement
has significantly improved detection of even relatively small
changes in the electric activity of particular fragments of
the cardiac muscle caused by e.g. ischaemia, effects of therapy,
heart infarct, etc.
Fig. 2. Fragment of the ECG recording a - standard b - after
analysis by the special computer program enhancing resolution
To facilitate the interpretation of ECG recording in the digital form and processed by the special computer program, the method of vectorcardiography was employed and hence the name of the method: high-resolution vectorcardiography. The method has been recently called numerical signal resolution enhancement electrocardiography - NURSE-ECG
Fig.3. The principle of vectorcardiogram construction. The red curve depicts the loop made by the tip of the moving vector of the electric dipole of depolarisation, in the cardiac muscle.
To be able to use the method, at first a standard recording of a healthy subject was obtained. NURSE recordings were made for a number of healthy people with no heart disease or circulation problems. Analysis of the recordings allowed establishment of a standard to which all recordings are compared.
NURSE-ECG is recorded by a 12-lead digital ECG apparatus, at our Department - made by MEDEA. The signals from each electrode are subjected to computer processing enhancing their resolution. As a result of a single procedure of signal processing we obtain:
- A diagram illustrating the course of beat depolarisation in three planes: frontal, transversal and saggital - a recording illustrating the movement of the temporary depolarisation vector of the septum and the left and right ventricula (Fig.3)
- Electric activity of the fragments of the cardiac muscle relative to that of the healthy subject (standard) expressed in percents,
- Graphical presentation of the electric activity of particular segments of the ventricles and interventricular septum compared with the standard, (Fig.3)
Fig. 4. Graphical presentation of activity of particular fragments of the cardiac muscle compared to the standard of a healthy subject.
NURSE-ECG studies have been conducted at the Department of Medical Physics, Institute of Physics, AMU, in cooperation with Cardiology Department of the MSWiA Hospital in Poznań. The database contains about 3000 of high-resolution vectorcardiograms collected for patients with different heart diseases and healthy subjects.