Cardiac arrhythmia analysis system

Claim 1

A system for identifying a QRS complex in an electro-cardiac signal representative of cardiac electrical activity, comprising: (a) differentiator means, responsive to said electro-cardiac signal, for producing the derivative thereof; (b) rectifying and filtering means, responsive to said electro-cardiac signal, for producing a signal representative of the low-pass filtered absolute value of said electro-cardiac signal; (c) first comparator means, responsive to the derivative of said electro-cardiac signal and to said low-pass filtered absolute value signal, for producing a resultant signal when the total of a predetermined reference level less the sum of said derivative and said low-pass filtered absolute value signal is greater than zero; and (d) output means, responsive to said resultant signal and to said low-pass filtered absolute value signal, for producing an output signal representative of the occurrence of a QRS complex upon the occurrence of said resultant signal when the amplitude of said low-pass filtered absolute value signal exceeds a predetermined threshold level.

Claim 2

A system for identifying a QRS complex in an electro-cardiac signal representative of cardiac electrical activity, comprising: (a) differentiator means, responsive to said electro-cardiac signal, for producing the derivative thereof; (b) rectifying and filtering means, responsive to said electro-cardiac signal, for producing a signal representative of the low-pass filtered absolute value of said electro-cardiac signal; (c) first comparator means, responsive to the derivative of said electro-cardiac signal and to said low-pass filtered absolute value signal, for producing a resultant signal when the total of a predetermined reference level less the sum of said derivative and said low-pass filtered absolute value signal is greater than zero; and (d) output means, responsive to said resultant signal and to said low-pass filtered absolute value signal, for producing an output signal representative of the occurrence of a QRS complex upon the occurrence of said resultant signal when the amplitude of said low-pass filtered absolute value signal exceeds a predetermined threshold level.

Claim 7

A method for analyzing an electro-cardiac signal to detect the occurrence of a QRS complex, comprising: (a) differentiating the electro-cardiac signal; (b) rectifying and filtering the electro-cardiac signal; (c) adding the derivative of the electro-cardiac signal to the rectified and filtered electro-cardiac signal to produce a sum signal; (d) comparing said sum signal to a reference level; and (e) comparing said rectified and filtered electro-cardiac signal to a predetermined threshold level, the occurrence of a QRS complex being indicated by the simultaneous occurrence of the sum of the derivative of said electro-cardiac signal and the rectified and filtered electro-cardiac signal being less than said reference level and said rectified and filtered electro-cardiac signal exceeding said threshold level.

Claim 8

A method for analyzing an electro-cardiac signal to detect the occurrence of a QRS complex, comprising: (a) differentiating the electro-cardiac signal; (b) rectifying and filtering the electro-cardiac signal; (c) adding the derivative of the electro-cardiac signal to the rectified and filtered electro-cardiac signal to produce a sum signal; (d) comparing said sum signal to a reference level; and (e) comparing said rectified and filtered electro-cardiac signal to a predetermined threshold level, the occurrence of a QRS complex being indicated by the simultaneous occurrence of the sum of the derivative of said electro-cardiac signal and the rectified and filtered electro-cardiac signal being less than said reference level and said rectified and filtered electro-cardiac signal exceeding said threshold level.