×

Physiological waveform detector

  • US 3,878,833 A
  • Filed: 10/09/1973
  • Issued: 04/22/1975
  • Est. Priority Date: 10/09/1973
  • Status: Expired due to Term
First Claim
Patent Images

1. A device for detecting the R-wave of an ECG waveform by identifying the time rate of change or slope of the R-wave as criteria of its existence to the exclusion of other waveform and noise characteristics, comprising:

  • a. means for differentiating said waveform and producing a differentiated waveform signal having peaks and valleys, b. means for receiving said differentiAted signal waveform and for converting it to a waveform signal representative of the absolute values of said peaks and valleys, c. comparator means having an input for receiving said absolute value signal and another input for receiving a reference signal, said comparator means producing an output signal change for a period during which the magnitude of said absolute value signal is greater than said reference signal, d. means for producing a reference signal including peak detector means receiving said absolute value signal and producing a signal corresponding with the maximum peak value thereof, and means for storing said peak signal for a short period, e. second means and normally nonconductive switch means interposed between said storing means and second means, said switch means being responsive to a control signal by transferring said peak signal to said second means, f. means connected to said second means for producing a signal having a magnitude equal to a predetermined percent of the signal magnitude of said second means, said last named signal constituting said reference signal which is applied to another of said comparator means inputs, said reference signal being representative of the magnitude of said waveform portion, g. timing means responsive to occurrence of an output signal change by said comparator means by initiating measurement of a first time interval which, if completed, is indicative of said R-wave having occurred, said timing means also being responsive to terminate measurement of said first interval if said comparator output signal change discontinues before expiration of said characteristic period as indicative of a signal other than an R-wave having occurred, h. means responsive to completion of said first time interval by actuating said timing means to continue to measure second and third time intervals, i. means responsive to completion of said second time interval by producing a control signal for operating said switch means to transfer said existing peak signal to said second means, and, j. means responsive to completion of said third time interval by resetting the signal on said first peak detector means to a level at which it can accept the next ensuing peak.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×