QRS Complex Of Electrocardiogram Research Articles

Phase progression of the QRS complexes in electrocardiograms versus the inscribing directions of the QRS loops in vectorcardiograms

Summary A simple means of cross-checking the vectorcardiographic loop-directions by the waveforms of electrocardiographic leads is described in this paper. The QR or RS segment shifts its phase within a QRS complex as an observer glances stroboscopically through the electrocardiograms of a coordinate plane. The inscription of the QRS loop on this plane by the terminal point of the “cardiac vector” must be made in a rotational direction the same as the phase progression of the QR or RS in leads around the origin. This method, having been checked with published cases, proves to be satisfactory.

A QRS Preprocessor Based on Digital Differentiation

Digital preprocessors can ease the increasing data collection demands placed on real-time computers in patient monitoring. This paper describes a preprocessor that detects in real time an electrocardiogram QRS complex and computes the R-R interval. Detection is performed using multiple digital differentiation, which is encouraging as an ultrareliable means for locating the QRS. Inherent in the technique is a dependable control that can automatically compensate for signal-level variations. Clinical data demonstrate that detection is insensitive to low- and high-frequency noise, from baseline drift to muscle artifact and cautery bursts. The device can be connected directly to a patient, whose safety is guaranteed by optoelectronic isolation and interelectrode current limiting. Preprocessor operation has been human-engineered to a simple on/off procedure.