Method and apparatus for detecting QRS complex of ECG

• US 5,048,535 A
• Filed: 06/12/1990
• Issued: 09/17/1991
• Est. Priority Date: 06/23/1989
• Status: Expired due to Term

• Current Assignee: Fukuda Denshi Company Limited
• Original Assignee: Fukuda Denshi Company Limited
• Inventors: Maruyama, Mitsuya
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US07/536,829
• Time in Patent Office: 462 Days
• Field of Search: 128/708
• US Class Current: 600/521
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval

Abstract

A method for detecting a QRS complex of an ECG is provided. The method includes the steps of inputting an ECG signal, setting a first threshold value based on a peak value of a QRS complex of the ECG signal, setting a second threshold value by estimating a noise level proprotional to the amount of noise included in the ECG signal comparing the first threshold value with the second threshold value, deeming a larger one of the first and second threshold values to be a third threshold value for detecting the QRS complex, detecting the QRS complex by using the threshold value for detecting the QRS complex, and outputting a synchronous signal synchronized with the detected QRS complex.

Claims

1. A method for detecting a QRS complex of an ECG, comprising:

inputting an ECG signal;

setting a first threshold value based on a peak value of a first QRS complex of said ECG signal;

setting a second threshold value by estimating a noise level proportional to an amount of noise included in said ECG signal;

comparing said first threshold value with said second threshold value;

setting the larger one of said first and second threshold values as a third threshold value for detecting a second QRS complex;

detecting said second QRS complex by using said third threshold value; and

outputting a synchronous signal synchronized with said detected second QRS complex.

2. A method for detecting a QRS complex of an ECG according to claim 1, wherein said second threshold value setting step further comprises the steps of:

estimating an average peak value of said amount of noise of said ECG signal; and

setting said second threshold value equal to twice said average peak value.

3. An apparatus for detecting a QRS complex of an ECG, comprising:

first threshold computing means receiving an ECG signal for generating a first threshold value based on a peak value of a first QRS complex of said ECG signal;

second threshold computing receiving said ECG signal for generating a second threshold value by estimating a noise level proportional to an amount of noise included in said ECG signal;

threshold comparing means receiving said first and second threshold values for comparing said first and second threshold values and outputting a larger one of them as a third threshold value for detecting a second QRS complex; and

synchronous signal outputting means receiving said third threshold value for detecting said second QRS complex and said ECG signal for detecting said second QRS complex of said ECG signal based on said third threshold value, and for outputting a synchronous signal synchronized with said detected second QRS complex.

4. The apparatus of claim 3, further comprising means for removing a pacemaker pulse from said ECG signal.

5. The apparatus of claim 3, wherein said ECG signal is a digital filtered ECG signal and wherein said apparatus further comprises:

converting means receiving an analog ECG signal for producing a digital ECG signal; and

filter means receiving said digital ECG signal for filtering said ECG signal so as to produce said digital filtered ECG signal.