ECG auto-gain control

• US 6,510,339 B2
• Filed: 12/06/2000
• Issued: 01/21/2003
• Est. Priority Date: 12/06/2000
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Paulson, Paul D., Kovtun, Vladimir V.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US09/731,520
• Publication Number:
  US 20020099300A1
• Time in Patent Office: 776 Days
• Field of Search: 600/508, 600/509, 600/515, 600/516, 600/517, 600/518, 600/521, 600/523, 128/898, 128/901, 128/903, 128/904, 607/4, 607/5, 607/25, 607/27, 607/28, 607/32
• US Class Current: 600/509
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A method and apparatus for automatic gain control (AGC) method are provided to control the output from a medical device monitoring electrical potentials. The AGC method and apparatus accumulate data indicative of at least one vector in a cycle buffer, calculate an amplitude representative of the signal, compare the calculated value with a set of thresholds, and calculate an adjustment to the gain setting based on the amplitudes relationship to the thresholds.

Claims

1. A method for automatic adjustment of gain, comprising:

receiving data representative of at least one vector from an electrocardiogram device;

determining an amplitude of the vector;

comparing the amplitude with a plurality of thresholds to establish a gain value for the vector; and

adjusting a gain setting based on the gain value.

2. A method, as in claim 1, further comprising:

establishing a baseline value for the vector, wherein the amplitude is determined relative to the baseline value.

3. A method, as in claim 2, wherein data above an exclusion threshold is excluded from the establishing the baseline value.

4. A method, as in claim 1, further wherein the relationship of the gain value is input into an algorithm to determine the gain setting.

5. A method, as in claim 1, wherein determining the amplitude of the vector occurs during a measurement window.

6. A method, as in claim 1, wherein the measurement window is initiated upon the amplitude of the vector crossing an initiation threshold.

7. A method, as in claim 1, wherein data indicative of the vector from the electrocardiogram device is decimated.

8. An device for auto-gain control, comprising:

at least one circle buffer for receiving data indicative of output of an electrocardiograph device;

a baseline detection circuit for establishing a baseline from the data;

a maximum amplitude detection circuit for establishing the maximum amplitude of the data relative to the baseline;

a comparator circuit for comparing a plurality of amplitudes from the maximum amplitude detection circuit with a plurality of thresholds; and

a decision circuit for determining a gain setting from a relationship between the plurality of amplitudes with the plurality of thresholds.