Cardiac coordinate system for motion analysis
An exemplary method includes accessing cardiac information acquired via a catheter located at various positions in a venous network of a heart of a patient wherein the cardiac information comprises position information with respect to time for one or more electrodes of the catheter; performing a principal component analysis on at least some of the position information; and selecting at least one component of the principal component analysis to represent an axis of a cardiac coordinate system. Various other methods, devices, systems, etc., are also disclosed.
1. A method comprising:
providing an electrocardiogram of a patient;
providing position information with respect to time, the position information acquired via an electrode located in a venous network of the patient;
defining a window based on the electrocardiogram; and
analyzing the position information within the defined window to determine a time of peak motion of the electrode wherein the analyzing analyzes the position information with respect to a cardiac coordinate system.
2. The method of claim 1 wherein the cardiac coordinate system comprises a cylindrical coordinate system.
3. The method of claim 1 wherein the cardiac coordinate system comprises a cardiac coordinate system defined at least in part by at least some of the position information.
4. The method of claim 3 wherein the cardiac coordinate system comprises a cardiac coordinate system defined at least in part by one or more of a principal component analysis and a prolate spheroid model.
5. The method of claim 1 wherein the defining a window comprises identifying a Q-wave in the electrocardiogram.
6. The method of claim 1 wherein the defining a window comprises identifying a T-wave in the electrocardiogram.
7. The method of claim 1 wherein the defining a window comprises defining a window based on a Q-wave and a T-wave.
8. The method of claim 1 wherein the window enhances accuracy in determination of a time of peak motion of the electrode as being related to an intrinsic or paced activation of the heart.
9. The method of claim 1 further comprising adjusting a cardiac therapy based at least in part on the time of peak motion.
10. The method of claim 1 further comprising identifying motion due to respiration based on a predefined respiratory motion direction in the cardiac coordinate system.
11. The method of claim 10 wherein defining the respiratory motion direction comprises performing a principal component analysis.
12. The method of claim 10 wherein the analyzing the position information comprises accounting for respiratory motion.
13. The method of claim 10 wherein the defining a window comprises defining a window based on the electrocardiogram and respiratory motion.
14. One or more non-transitory computer-readable media comprising processor executable instructions to instruct a computing device to: access an electrocardiogram of a patient; access position information with respect to time, the position information acquired via an electrode located in a venous network of the patient; define a window based on the electrocardiogram; and analyze the position information, with respect to a cardiac coordinate system, within the defined window to determine a time of peak motion of the electrode.