ECG recording by a microdot thermal printer

Recently high quality ECG records have been obtained by means of microdot thermal printers, because of their numerous advantages. Usually they contain a shift register in the thermal head and the fast control of the dot locations to be heated is an important software problem. We implemented the TLP 480Z-N Gotemba thermal printer (made in Japan) in our ECG instruments, and elaborated two algorithms for lengthwise and crosswise printing on the paper. They use 'black and white' strips loaded into the shift register by 1-byte parallel data organization. The lengthwise mode can operate in real time, while the crosswise one is intended for memorized signals.