The Performance Of Picturephone Systems In Transmitting Medical Data

PICTUREPHONE® service, the Bell System's two-way audio-visual telephone service, is currently available as switched network systems in the Chicago Loop and Oak Brook areas and in certain other parts of the country as switched intercom systems. A PICTUREPHONE system has many potential applications in health care such as remote interactive consulta-tion, remote viewing of patients, charts, instruments, some X-rays and microscope slides. It can also be used to retrieve patient data from computerized medical record files. This paper briefly describes PICTUREPHONE systems, the character-istics of the camera tube, signal conditioning and the display unit. Overall performance data are given for optical sensitivity, spectral response, MTF and luminance transfer function. The transmission of electrocardiograms, X-rays and microscope slides are used as examples to illustrate image clarity. By means of alternative lenses and filters the performance of a PICTUREPHONE system, which was pri-marily designed for face-to-face visual telephony, can be improved for transmitting medical data.