CATHETERS, SYSTEMS, AND RELATED METHODS FOR MAPPING, MINIMIZING, AND TREATING CARDIAC FIBRILLATION
Catheters, systems, and related methods for optimized for mapping, minimizing, and treating cardiac fibrillation in a patient, including an array of at least one stacked electrode pair, each electrode pair including a first electrode and a second electrode, wherein each electrode pair is configured to be orthogonal to a surface of a cardiac tissue substrate, wherein each first electrode is in contact with the surface to record a first signal, and wherein each second electrode is separated from the first electrode by a distance which enables the second electrode to record a second signal, wherein the catheter is configured to obtain one or more measurements from at least a first signal and a second signal in response to electrical activity in the cardiac tissue substrate indicative of a number of electrical circuit cores and distribution of the electrical circuit cores for a duration across the cardiac tissue substrate.
1 . (canceled)
2 . A method for identifying electrode tissue contact in a cardiac mapping catheter, the method comprising the steps of:
contacting cardiac tissue with a catheter comprising an array of orthogonal close unipolar (OCU) electrode pairs with a known inter-electrode spacing;
measuring a first rate of change in an electrogram amplitude from a first electrode;
measuring a second rate of change in an electrogram amplitude from a second electrode; and
identifying which of the first and second electrodes is in contact with the cardiac tissue as the electrode with the greatest rate of change.
3 . The method of claim 3 , wherein the rate of change of each of the first and second electrodes is compared to a threshold value and the electrode that is above the threshold value is determined to be in contact with the cardiac tissue.
4 . The method of claim 2 , wherein the rate of change of each of the first and second electrodes is compared to a threshold value and the electrode that is below the threshold value is determined not to be in contact with the cardiac tissue.
5 . The method of claim 2 , wherein the threshold value is determined by:
placing the array of OCU electrode pairs perpendicular to the tissue surface;
recording unipolar electrograms from each electrode in the electrode pairs;
calculating dV/dt for each electrode and identifying 20 peak negative values within a time window;
averaging the 20 peak negative values;
plotting the averaged 20 peak negative values relative to height above the cardiac tissue; and
determining a delta dV/dt value between the first electrode and the second electrode in the electrode pairs, wherein the delta dV/dt value is used as the threshold value.
6 . The method of claim 5 , wherein the time window is about 4.5 seconds.
7 . The method of claim 3 , wherein the electrode that is above the threshold value is also determined to be orthogonal to the cardiac tissue.
8 . The method of claim 4 , wherein the electrode that is below the threshold value is determined not to be orthogonal to the cardiac tissue.
9 . The method of claim 2 , wherein the OCU electrode pairs are stacked OCU electrode pairs.