As many as 16 channels of analog information, for example, circulatory pressures, flows, and electrocardiogram, can be recorded on video tape or disc simultaneously with video angiograms or other video material. Circuitry is described that may be used to pulse height modulate a 2 μs segment of the initial, normally unused left margin of each horizontal video line. This provides the capability of recording a signal every 63.5 μs or 15,750 samples/s. The 16 channels of information can be recorded simultaneously at rates as high as 984 samples/s per channel by multiplexing the signals. Similar demodulator circuitry reconstructs the analog signal from the composite video image in a form suitable for oscilloscopic display or analog to digital conversion. This system is particularly suitable for recording and retrieving hemodynamic data in analog form in exact synchrony with simultaneous X ray video angiographic images of circulatory structures such as the left ventricle. It is particularly useful in conjunction with stop action or slow motion analysis of these images using a video disc or helical scan type video tape recorder.
ASJC Scopus subject areas
- Physiology (medical)