Multiple lead ECG monitoring

The prototype described provides a means of real time display and analysis of the ST segment in a 12-lead ECG. By displaying the signal averaged P-QRS-T complexes for the 12-lead as a static image over a 10 second period the large amount of information contained in the display can be fairly readily assessed. Since the ST segment changes which occur during myocardial ischaemia evolve over a period of minutes rather than on a beat to beat basis, analysis of the ST segment at 10 second intervals provides an adequate basis for monitoring. By incorporating a single lead for a continuous display, the rhythm can also be monitored on a beat to beat basis. The present system is limited to data sampling at 100 Hz and the processor and data structures are all limited to 8 bits. The prototype has been successfully used to monitor patients with unstable angina, patients undergoing coronary thrombolysis and angioplasty