[The electrocardiomultigraphimeter and the Commodore-64. How to use the home computer with great skill]

The drop in hardware costs has fostered the widespread use of home-computing systems. Because of this situation, the home-computer can be profitably employed in some highly specialized fields. We believe electrocardiographic instrumentation to be one of such fields. We have built an electrocardiomultigraphimeter (ECXGM), which can be considered as a development of the traditional electrocardiograph that fulfills some additional functions. Our prototype features vectorcardiography, polar coordinate tracing, automatic measurements between fiducial points selected by the user with a joystick and cursor on the screen and trace filing by patient, on labelled floppy disks. The conventional hardware consists of a Commodore 64 console, a monitor, two floppy disk drives and an Epson HI-80 plotter, all of them readily available. The special hardware consists of an A/D converter, which receives the electrocardiographic signal downstream of the amplifying stage which is a standard feature of any electrocardiograph. Prototype development mostly involved the software. Difficulties were posed by the limited resources available on home-computers, an important point in view of the problem to be tackled. The solutions adopted are based on the use of the ASSEMBLER language, overloading techniques and on minimizing the interconnections among the software modules defined in a compactly built program. The result is an instrument having significantly advanced clinico-scientific capabilities as compared to current electrocardiographic instruments. This factor, and the class of the hardware used and special software built confer originality to this work.(ABSTRACT TRUNCATED AT 250 WORDS)