Lead positioning for an implantable pulse generator
A method of cardiac signal processing including: receiving measurements from at least two electrodes positioned within the heart; determining, using the measurements, relative positioning of the at least two electrodes relative to each other; evaluating suitability of the relative positioning of the at least two electrodes for measurement of cardiac activity to determine which cardiac cycles should receive cardiac contractility modulation stimulation.
1 . A system for cardiac stimulation comprising:
an implantable controller, said controller configured to carry out the method of:
receiving measurements from at least two electrodes positioned within the heart;
designating, based on said measurements, one electrode of said at least two electrodes as a first electrode, and another electrode of said at least two electrodes as a second electrode;
generating a signal to cause application of cardiac contractility modulation stimulation to said heart, if a ventricular event is detected at said first electrode and later, after a suitable time delay, at said second electrode.
2 . The system according to claim 1 , wherein said designating comprises monitoring said measurements for a plurality of cardiac cycles and designating said first electrode for an electrode of said at least two electrodes which senses a ventricular event first for more than half of said cardiac cycles.
3 . The system according to claim 1 , wherein said measurements comprise cardiac electrical measurement signals from said at least two electrodes which are positioned at a right ventricle septum.
4 . The system according to claim 1 , wherein said designating comprises identifying, from said measurements, timing of arrival of a cardiac action potential wave-front at said at least two electrodes.
5 . The system according to claim 1 , wherein said at least two electrodes includes a first and a second electrode positioned at a septum and at least one additional electrode, where said measurements include measurement of potential at said first and said second electrode each with respect to said additional electrode.
6 . The system according to claim 1 , wherein said delay is at least 1 ms and at most 4 ms.
7 . The system according to claim 1 , configured to generate an alert if said delay is not within a desired range.
8 . The system according to claim 1 , configured to perform impedance measurements at and/or between said two electrodes.
9 . The system according to claim 1 , wherein said system is configured to perform said applying at both of said electrodes, overlapping in time.
10 . The system according to claim 1 , wherein said system is configured to perform said applying at both of said electrodes in a same cardiac cycle, at least in part, not overlapping in time.
11 . The system according to claim 1 , comprising changing previous designating in response to periodic measurements from the electrodes.
12 . The system according to claim 1 , wherein designating comprises designating at least one electrode as right ventricle (RV), and at least one electrode as left ventricle (LS).
13 . A method of monitoring comprising:
monitoring, over time, a time difference between arrival of a cardiac action potential wave-front at two electrodes, each positioned at a different point on a heart;
based on said monitoring one or more of:
designating relative position of the two electrodes, based on said time difference, for determination of which cardiac cycles should receive cardiac contractility modulation stimulation.
14 . The method according to claim 13 , wherein said two electrodes are each positioned at a different point on a heart septum.
15 . The method according to claim 13 , wherein said monitoring comprises, for a plurality of cardiac cycles:
receiving cardiac electrical measurement signals from said two electrodes;
identifying timing of arrival of a cardiac action potential wave-front at each of said two electrodes from said measurement signals;
determining a time difference between arrival of said cardiac action potential wave-front at said two electrodes, for a plurality of cardiac cycles; and
generating, from time differences determined for said plurality of cardiac cycles, a statistical representation of said time differences.
16 . The method according to claim 13 , wherein said determining comprises determining a sign of said time difference.
17 . The method according to claim 15 , wherein said wherein said statistical representation comprises a propensity of which electrode of said two electrodes senses said cardiac action potential wave-front first.
18 . The method according to claim 13 , wherein said designating comprises designating the electrode for which more than half of the wave-fronts are sensed first as being closer to an a trioventricular node.
19 . The method according to claim 15 , wherein said method further comprises diagnosing a cardiac condition based on said determination; and wherein said diagnosing comprises comparing said statistical representation with a threshold.
20 . The method according to claim 15 , comprising receiving heart rate measurements, for said plurality of cardiac cycles; and
wherein said generating comprises generating a statistical representation of said time differences with respect to heart rate;
wherein if said statistical representation indicates increase in variation of time differences with increased heart rate, diagnosing potential induced ischemia; wherein said increase heart rate includes statistical representations of said time differences for heart rates over a threshold rate;
wherein if said statistical representation indicates increase in variation of time differences for one or more heart rate, diagnosing potential cardiac arrhythmia.
21 . The method according to claim 15 , wherein said statistical representation of said time differences is a median of said time differences for a time period.
22 . The method according to claim 21 , wherein if said median deviates by more than a threshold value over a time period of less than a minute, lead dislodgement is identified.
23 . The method according to claim 13 , comprising selecting, during implantation of the electrodes, positioning of lead portions of each of the two electrodes based on the monitored time difference.
24 . A system for cardiac stimulation comprising:
an implantable controller, said controller configured to carry out the method of:
receiving measurements from at least two electrodes positioned within the heart;
designating, from said measurements, a first electrode of said at least two electrodes and a second electrode of said at least two electrodes;
wherein said designating comprises monitoring said measurements for a plurality of cardiac cycles and designating said first electrode for an electrode of said at least two electrodes which senses a ventricular event first for more than half of said cardiac cycles;
applying cardiac contractility modulation stimulation to said heart if a ventricular event is detected at said first electrode and then at said second electrode after a suitable time delay.
25 . A system for cardiac stimulation comprising:
an implantable controller, said controller configured to carry out the method of:
receiving measurements from at least two electrodes positioned within the heart;
designating, from said measurements, a first electrode of said at least two electrodes and a second electrode of said at least two electrodes;
wherein said designating comprises identifying, from said measurements, timing of arrival of a cardiac action potential wave-front at said at least two electrodes;
applying cardiac contractility modulation stimulation to said heart if a ventricular event is detected at said first electrode and then at said second electrode after a suitable time delay.