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Biomedical subjects

M Nasor

Publications and source records attributed to M Nasor.

2 recordsLinked to original sources
PubMedDate not supplied

An accurate programmable ECG simulator.

This article reports the design and development of an ECG simulator intended for use in the testing, calibration and maintenance of electrocardiographic equipment. It generates a lead II signal having a profile that varies with heart rate in a manner which reflects the true in vivo variation. Facilities are provided for user adjustment of heart rate, signal amplitude, QRS complex up-slope, and the relative amplitudes of the P-wave and T-wave. The heart rate can be set within the range 30-200 beats min(-1) in steps of 1 beat min(-1). The amplitude of the QR5 complex can be adjusted from 0.1-20 mV in 0.1 mV steps, while its up-slope can be set between 10 and 50 ms with a 1 ms resolution. The amplitude of the P-wave can be varied from 5-40% and that of the T-wave from 10-80% of the amplitude of the QRS complex with a 1% resolution.

Algorithms↗
PubMedDate not supplied

The time relationships of the constituent components of the human electrocardiogram.

This paper reports the results of an examination of the timing relationships of the principal constituent components of the human electrocardiogram (ECG). ECG recordings were obtained from 21 healthy subjects, 10 male and 11 female aged between 13 and 65 years, over a wide range of heart rates extending from 46 to 184 beats per minute (bpm). A wavelet transform method based on the Mexican Hat wavelet was then used to precisely locate the positions of the onset, peak, termination and the duration of individual components in the ECG. Component times were then classified according to the heart rate associated with the cardiac cycle to which the component belonged. Second-order equations in the square root of the cardiac cycle time, TR-R of theform AT(1/2)R-R+BT R-R+C were fitted to the data obtained for each component to characterize its timing variation. These equations may be used to synthesize an ECG signal having a profile that varies with heart rate in a manner which reflects the in vivo variation.

Adolescent↗