3759248 is referenced by 32 patents and cites 3 patents.

A system is described to continuously monitor a number of cardiac patients in a hospital. Electrocardiogram probes are placed upon a plurality of patients and simultaneously monitored by this system for changes in the normal electrocardiogram (ECG) waveforms. Each ECG waveform is recorded on a 30 second tape loop delay for retrieval during an alarm condition for a determination of the cause of the alarm. This tape loop also provides a 100 millisecond delay of ECG for correlation monitoring of the QRS complex of the ECG. An R wave trigger is generated and is utilized for R-R interval measurements. A correlation monitor is provided and quantizes the ECG QRS complexes and stores each segment thereof for comparison with subsequent waveforms. The stored waveform provides a running average of several QRS complexes just prior to the complex being compared. A segment element is trained by this running average of the QRS waveform. By comparing each segment of the waveform to the appropriate segment of the stored waveform, a correlation is established. If an aberrant QRS complex is sensed and compared, several points of difference will be detected. The R-R interval is simultaneously compared on a running average to assist in establishing a premature ventricular contraction of the patient. A photoplethysmograph is provided to monitor mechanical heart action. The signals provided by the R-R interval monitor, a change in the QRS complex, pulse signals provided by the photoplethysmograph and the heart rate of the patient provide certain criteria which are monitored by a logic circuit to provide a minor alarm on certain criteria and a major alarm on any combination of the waveforms.

Title
Cardiac arrythmia detector
Application Number
05/113,331
Publication Number
3759248
Application Date
February 8, 1971
Publication Date
September 18, 1973
Inventor
Valiquette Donley J
Assignee
Spacelabs
IPC
A61b 05/04
A61B 05/452
A61B 05/436
A61B 05/432
A61B 05/468
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