System for comparing a real-time waveform with a stored waveform

Abstract

A system for storing time-varying kinesiograph waveforms and continuously displaying the stored waveforms on the screen of a cathode-ray tube (CRT). In a recording mode, the waveforms are periodically sampled, digitized, and then stored in a block of random access memory reserved for that waveform. In a display mode, the Y axis of the CRT is driven by a digital-to-analog converter which receives digitized samples from the memory block corresponding to the displayed waveform. The X axis of the CRT is driven by a second digital-to-analog converter, which, in an X-Y mode, also receives digitized samples from a selected block of memory. In a sweep mode, the X axis digital-to-analog converter receives the continuously incrementing memory addresses, which read out digitized samples from the memory block for the displayed waveform. The system may also display an expanded portion of a waveform in the sweep mode by incrementing the memory address from one of several predetermined values. In the X-Y mode, two pairs of kinesiograph waveforms may be displaced with respect to each other on the left and righthand sides of the CRT screen. A multiplexer for the X and Y axes allows a real-time kinesiograph waveform to be superimposed on the same stored waveform to facilitate mandibular movement comparisons. The system may also operate in a sensor positioning mode in which a line connecting the optimum position of the sensors and the current position of the sensors is generated on the screen of the CRT.