Superimposition of analogue data onto a video image: a new technique

There are many tools to aid the clinician in making an accurate medical diagnosis including various imaging techniques and recording analogue signals from the patient. A new, inexpensive method of combining a video image and the instantaneous values of analogue waveforms is described here. The system, TVDATA, is reliable, compact and portable and has been successfully used in various clinical situations. The unit requires a standard video source, such as a camera, a TV monitor, a video recorder and the output from the analogue source or sources. The analogue data are converted into a digital signal and then displayed in a convenient part of the screen as a horizontal bar. Two types of data channel are available--uni- and bidirectional. A number of these channels can be used to record different analogue parameters and an inbuilt octal frame counter assists subsequent review of the video record.