ECG signal power vector detection of ischemia or infarction
First Claim
Patent Images
1. A method comprising:
- sensing at least one cardiac signal representative of cardiac activity of a subject using an implantable medical device (IMD);
calculating, from the cardiac signal, a first dominant vector corresponding to a direction and magnitude of maximum signal power of an ST-T first segment of a cardiac cycle and a second dominant vector corresponding to a direction and magnitude of maximum signal power of a P-QRS second segment of a cardiac cycle, wherein the P-QRS segment includes the P-wave and extends to and includes the S-wave;
measuring a change in the first dominant vector;
measuring a change in the second dominant vector;
subtracting the change in the second dominant vector from the measured change in the first dominant vector to form a difference; and
deeming an ischemic event to have occurred at least in part from whether the difference exceeds a specified threshold value.
0 Assignments
0 Petitions
Accused Products
Abstract
A method comprising sensing at least one cardiac signal representative of cardiac activity of a subject using an implantable medical device (IMD), calculating, from the cardiac signal, a first dominant vector corresponding to a direction and magnitude of maximum signal power of an ST-T first segment of a cardiac cycle and a second dominant vector corresponding to a direction and magnitude of maximum signal power of a P-QRS second segment of a cardiac cycle, measuring a change in the first dominant vector, measuring a change in the second dominant vector, and subtracting the change in the second dominant vector from the measured change in the first dominant vector to form a difference.
76 Citations
19 Claims
-
1. A method comprising:
-
sensing at least one cardiac signal representative of cardiac activity of a subject using an implantable medical device (IMD); calculating, from the cardiac signal, a first dominant vector corresponding to a direction and magnitude of maximum signal power of an ST-T first segment of a cardiac cycle and a second dominant vector corresponding to a direction and magnitude of maximum signal power of a P-QRS second segment of a cardiac cycle, wherein the P-QRS segment includes the P-wave and extends to and includes the S-wave; measuring a change in the first dominant vector;
measuring a change in the second dominant vector;subtracting the change in the second dominant vector from the measured change in the first dominant vector to form a difference; and deeming an ischemic event to have occurred at least in part from whether the difference exceeds a specified threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A system comprising
an implantable medical device (IMD) comprising: -
a plurality of implantable electrodes adapted for spatial distribution within a subject; and at least one cardiac signal sensing circuit in communication with the electrodes, the cardiac signal sensing circuit operable to produce an electrical cardiac signal representative of cardiac activity of the subject; and means for calculating, from the electrical cardiac signal, a first dominant vector corresponding to a direction and magnitude of maximum signal power of an ST-T first segment of at least one cardiac cycle of the subject and at least a second dominant vector corresponding to a direction and magnitude of maximum signal power of a P-QRS second segment of the cardiac cycle, wherein the P-QRS segment includes the P-wave and extends to and includes the S-wave, and forming a difference by subtracting a measured change in the second dominant vector from a measured change in the first dominant vector, and using the difference to reduce noise in the measured change in the first dominant vector. - View Dependent Claims (15, 16, 17, 18, 19)
-
Specification