Trends in electrocardiograph design

This paper describes some of the techniques used in electrocardiograph design today together with the rationale behind them. The basic requirements for electrocardiograph design are discussed together with their implementation in three different types of electrocardiograph typical of those currently in use. The first is the conventional single-channel electrocardiograph comprising total analogue circuit design which is the most widely used at present, primarily because of its low cost. The second incorporates microprocessor techniques to record, store and transmit the electrocardiogram data to a central computer for analysis. Finally, a specific commerciallyavailable microprocessor-based electrocardiograph which incorporates analysis of the electrocardiogram with immediate print-out of the report is described. The electrocardiograph has progressed from a machine which records and displays the electrocardiogram waveform to a machine which can also analyse it and print the report within a few seconds. Despite these major advances in design features, the relatively high cost of the microprocessor based electrocardiographs and associated electrocardiogram interpretation systems has restricted their use. Improvements in technology would be expected to reduce the cost of such electrocardiographs, thereby making their use more widespread within the health service.