Apparatus and method for printing annotated electrocardial data
AssigneeDel Mar Avionics
InventorJohn A. Bachman
Life of this patent
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Abstract
A single-beam CRT printer, used as a validator record of electrocardiographic data played back from a magnetic tape at a much higher speed than the speed at which it was recorded, includes a scan circuit for generating signals for steering the beam alternately through an ECG scan pattern and through a character scan pattern and further includes a character generator for modulating the intensity of the beam in relation to the instantaneous location of the beam within the character scan pattern to cause the beam to print characters, the intensity of the beam and its linear velocity being increased during execution of the character scan pattern to permit the characters to be printed at such a high speed that only an insignificant part of the ECG plot is omitted while the characters are being printed.
Claims6
In a high speed data playback CRT printer having a single beam and an X and Y drive circuit of the type used to plot an applied, analog, ECG signal on a recording medium, and improvement for intermittently also printing on the recording medium, at times determined by an applied timing signal, characters represented by applied character signals and for printing the characters at such a high speed that only an insignificantly small part of the analog ECG plot is omitted while the characters are being printed, said improvement comprising:
- scan circuit means for generating in response to an applied scan select signal an analog ECG scan signal and a raster character scan signal and for applying the analog ECG scan signal in an X-Y trace and the character scan signal in a raster trace to the CRT to alternately steer the beam through respectively an ECG scan X-Y tracing pattern at a first linear speed and through a character scan raster pattern at a second linear speed at least several times the first linear speed;
- character generator means for modulating the intensity of the beam in relation to the instantaneous location of the beam within the character scan raster pattern and in relation to the applied character signals to cause the beam to print the characters, said character generator means responsive to an applied intensity control signal to maintain the intensity of the beam at a first level while the analog ECG signal is being traced to an X-Y plot and to increase the intensity of the beam when the characters are being traced in a raster scan to a second level at least several times greater than the first level to prevent diminution of intensity when it moves at the second linear speed;
- and,
- control means connected to said scan circuit means and responsive to the applied timing signal for generating the scan select signal applied to said scan circuit means, and connected to the CRT for selectively passing the CRT the applied analog ECG signal when the beam is being steered through the ECG scan X-Y tracing pattern for generating the intensity control signal in relation to the applied timing signal, and further connected to said character generator means for applying thereto the intensity control signal.
Dependencies are inferred from the claim text.