Electrocardiographic means and method for detecting potential ventricular tachycardia

Claim 3

The method of claim 1 further including the step of generating a presence or absence signal which is a function of said comparison.

Claim 4

The method of claim 1 further including the step of averaging the digital values of said series of QRS signals to obtain an averaged composite QRS signal before the application thereof to said high pass filter means.

Claim 5

The method of claim 3 wherein said portion of said time segments includes the last 40 milliseconds of the averaged QRS signal.

Claim 6

The method of claim 4 wherein said arithmetic value is the root mean square.

Claim 7

The method of claim 2 further including the step of measuring the duration of said averaged QRS signal.

Claim 8

Apparatus for analyzing electrocardiograph signals to determine the level of high frequency energy in the late QRS signal comprising: means for converting X, Y, and Z lead electrocardiographic input signals to digital valued time segments; means for examining said X, Y, and Z digital valued time segments and selecting therefrom the QRS waveform portions thereof; means for signal averaging a multiplicity of said selected QRS waveforms for each of said X, Y, and Z inputs and providing composite, digital X, Y, and Z QRS waveforms; high pass filter means; means for applying to said filter means, in reverse time order, the anterior portion of each said digital X, Y, and Z waveform; and means for comparing the output of said filter means with a predetermined level to obtain an indication of the presence of a high frequency, low level, energy component in the filter output of said anterior portions.

Claim 9

Apparatus for analyzing electrocardiograph signals to determine the level of high frequency energy in the late QRS signal comprising: means for converting X, Y, and Z lead electrocardiographic input signals to digital valued time segments; means for examining said X, Y, and Z digital valued time segments and selecting therefrom the QRS waveform portions thereof; means for signal averaging a multiplicity of said selected QRS waveforms for each of said X, Y, and Z inputs and providing composite, digital X, Y, and Z QRS waveforms; high pass filter means; means for applying to said filter means, in reverse time order, the anterior portion of each said digital X, Y, and Z waveform; and means for comparing the output of said filter means with a predetermined level to obtain an indication of the presence of a high frequency, low level, energy component in the filter output of said anterior portions.

Claim 10

The invention as defined in claim 7 wherein said comparing means examines only a portion of said filter's output.

Claim 11

The invention as defined in claim 8 wherein said portion of said filter's output represents the filtered last 50 milliseconds of the QRS waveform.

Claim 12

The invention as defined in claim 9 wherein said comparing means combines selected portions of said filter's output for each of the X, Y, and Z signals and calculates the root mean square value of said combined portions.

Claim 13

The invention as defined in claim 10 further comprising: means for applying to said filter means, in forward time order, the early portion of each said digital X, Y, and Z QRS waveforms; means for extracting from said filter's output the time of commencement of said QRS waveform; and means responsive to said extraction means and said comparing means for determining the width of said QRS waveform.

Claim 14

Apparatus for analyzing electrocardiograph signals comprising: means for converting electrocardiographic input signals to digital QRS waveform segments; high pass filter means: means for applying to said filter means, in reverse time order, the anterior portion of each said digital QRS waveform; and means for comparing the output of said filter means with a predetermined level.

Claim 15

Apparatus for analyzing electrocardiograph signals comprising: means for converting electrocardiographic input signals to digital QRS waveform segments; high pass filter means: means for applying to said filter means, in reverse time order, the anterior portion of each said digital QRS waveform; and means for comparing the output of said filter means with a predetermined level.

Claim 16

The invention as defined in claim 13 wherein said means for comparing examines only a portion of said filter's output.

Claim 17

The invention as defined in claim 13 wherein said portion of said filter's output represents the filtered last 50 milliseconds of the QRS waveform.

Claim 18

The invention as defined in claim 13 wherein said means for comparing combines selected portions of said filter's output and calculates the root mean square value of said combined portions.

Claim 19

The invention as defined in claim 12 or 15 further comprising: means for applying to said filter means, in forward time order, the early portion of each digital QRS waveform; means for extracting from said filter's output the time of commencement of said QRS waveform; and means responsive to said extraction means and said means for comparing for determining the width of said QRS waveform.