Continuous monitoring by microprocessor from the operating room to the intensive care unit

The "Chronicler" is made up of a microcomputer (the CPU is a Motorola 6809), an alphanumeric-graphic display with keyboard and a printer. The system is connected to several physiological signal monitors and in our application to a mechanical ventilator under electronic control. It collects every 5 seconds - or at each breathing cycle if required - all the data supplied by the various measuring devices including those in the mechanical ventilator. The time basis for displaying and storing the data is a multiple of the data acquisition time basis; it is selected interactively by the user during operation. Up to five raw analog curves (f.i. capnogram, pulmonary artery pressure curve) can be displayed and their morphology can then be examined. Manual data are entered or retrieved at any time. The system was designed by Dr. Demeester's team in order to help the anesthesiologist during and after anesthesia. Clinical use of the system by our staff has convinced us that indeed it is of great help in the control of general anesthesia: this results from the very clear and efficient presentation of the data both as numbers and curves; an alarm program under interactive control of the user makes surveillance still easier; furthermore the use of the system is simple and convenient. Finally, when surgery is over, a standard report is automatically printed; it is equivalent to a manually written anesthesia report. The data are stored on floppy disks and can be processed later for retrospective analysis in order to investigate, for instance, the influence of surgical maneuvers and of drugs on physiological parameters. The "Chronicler" is thus a tool for dynamic monitoring during anesthesia; it is also a powerful tool for clinical and physiological research.