VENTRICULAR ARRHYTHMIA DETECTION SYSTEM

• US 3,598,110 A
• Filed: 04/10/1969
• Issued: 08/10/1971
• Est. Priority Date: 04/10/1969
• Status: Expired due to Term

• Current Assignee: Karl W. Edmark
• Original Assignee: Karl W. Edmark
• Inventors: Edmark, Karl W.
• Application Number:
  US04/815,134
• Time in Patent Office: 852 Days
• US Class Current: 600/515
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia

Abstract

A system is disclosed for detecting the occurrence of a premature ventricular contraction in a patient or in the signals provided by a training apparatus which generates signals representing a premature ventricular contraction (PVC). The electrocardiograph signals from the patient or a training apparatus are applied via differentiating circuit and filter circuit to a logic system which operates to analyze the QRS signals to determine whether or not the QRS signal is a normal signal or whether it is the result of a PVC. Pulse generating circuits are used to define timing arrangements so that if the signal is the result of or represents a PVC then an alarm circuit is activated. Details of the logic circuitry and of a system wherein horizontal markers are provided on the cathode-ray tube display of the QRS signal to facilitate utilization of the equipment by a person unskilled in the electronic arts are provided.

Claims

1. A system for monitoring electrocardiograph signals comprising in combination:

signal input means for receiving electrocardiograph input signals which include QRS signals;

a first signal-generating means connected to said signal input means and providing a first signal defining a fixed time interval in response to the Q-R portion of an input signal exceeding a predetermined magnitude;

second signal-generating means connected to said signal input means and providing an information signal in response to any input electrocardiograph signal changing in the R-S direction and achieving a selected amplitude;

information signal-monitoring means;

signal-gating means connected to said first signal-generating means for control thereby and between said monitoring means and said second signal-generating means, said signal-gating means preventing the application of an output signal to said monitoring means from said second signalgenerating means during said time interval; and

a third signalgenerating circuit connected between said second signalgenerating circuit and said signal input means and providing a control signal to said second signal-generating circuit operative to hold said second signal-generating circuit against recycling for a predetermined time following generation of a said information signal.

2. A ventricular arrhythmia detection system comprising in combination:

a signal input circuit means;

a first signal-generating circuit coupled with said input circuit means and responsive to the leading edge of a normal QRS electrocardiograph signal reaching a first amplitude to provide a first signal which terminates during the RS portion of a normal QRS signal;

second signal-generating circuit means coupled with said input circuit means and responsive to any input signal changing in the R-S direction of a normal QRS signal reaching a second condition to provide a second signal, said second signal occurring prior to termination of said first signal for a normal QRS signal and subsequent thereto for a QRS signal having a duration longer than normal;

signal-gating circuit means connected to each of said signal-generating circuit means and providing an information signal only in response to the occurrence of said second signal during the absence of said first signal;

alarm circuit means connected to said signal-gating circuit means and responsive to information signals therefrom; and

signal display means including an oscilloscope connected to said input circuit means and having beam deflection control circuits coupled with said first and second signal-generating circuit means to provide horizontal visual markers on the QRS wave of an electrocardiograph signal upon the occurrence of said first and second signals.

3. The system of claim 2 including a thIrd signal-generating circuit connected between said input circuit means and said second signal-generating circuit means and providing a signal which first triggers said second signal-generating circuit means and then holds the same against further triggering for a predetermined time.