On-line mapping system for the visualization of the electrical activation of the heart

A simple but still versatile datalogging system based on a VCR (video cassette recorder) has been developed. The VCR allows mass storage of data originating from a maximum of 256 channels as used, for example, in the recording of the time-dependent potential distribution at the surface of the myocardium [1,2]. Incorporated in the system is a display memory allowing on-line simultaneous visualization of the assessed recordings of 16 channels. On an interactive base display parameters (time-window, channel-selection) can be altered without loss of data. A link with a personal computer allows modification of system parameters and storage of data for off-line analysis of the recorded data. The high data rate to and from the VCR (4.3 MHz) fully utilizes the bandwidth available. A normal videotape can, therefore, contain up to 2 Gigabyte of data. Despite this, the use of the tapecounter and the decoding of the time-code inserted into the signal allows quick retrieval of the stored data without needing expensive equipment. The system described brings mass data logging within the reach of a vast number of laboratoria and cardiovascular centers.