Systems and methods for generating therapeutic electric fields for capture of nervous system targets
A neuromodulation system includes neuromodulation electrodes on an electrode support that is positionable within a blood vessel for transvascular stimulation of target nerves. Cathode surface area, cathode-to-anode spacing, and other parameters are selected for capture of specific types of nerves (sympathetic, parasympathetic, and/or mixed nerves), nerves located at larger or shorter distances from the vascular wall, and also for proper nerve capture for the targeted types of nerves.
1. A neuromodulation system comprising:
a plurality of neuromodulation electrodes on a common electrode support, the support positionable within a blood vessel to position electrodes within the plurality of electrodes in contact with an interior wall of the blood vessel; and
a stimulator configured to activate at least a subset of the plurality of electrodes to generate an electric field to capture target nerves disposed external to the blood vessel;
wherein the system includes
a mixed nerve capture mode for capturing both parasympathetic and sympathetic nerves, wherein in the mixed nerve capture mode a first combination of the plurality of electrodes is activated to create an anode and a cathode, the anode and cathode in the mixed nerve capture mode having a first separation distance between them, wherein the cathode in the mixed nerve capture mode is comprised of one or more of the electrodes and has a first combined surface area positioned for contact with the blood vessel wall, and
an independent nerve capture mode, wherein in the independent nerve capture mode a second combination of the plurality of electrodes is activated to create an anode and a cathode having a second separation distance between them, wherein the cathode in the independent nerve capture mode is comprised of one or more of the electrodes and has a second combined surface area positioned for contact with the blood vessel wall, wherein the first separation distance is greater than the second separation distance, and the first combined surface area is greater than the second combined surface area;
wherein in the mixed nerve capture mode the system generates an electric field that is wider and deeper than an electric field generated by the system in the independent nerve capture mode, and wherein in at least one of the mixed nerve capture mode and the independent nerve capture mode, the cathode is formed from an activated plurality of the plurality of electrodes on the electrode support; and
wherein the system is configured to capture, in the mixed nerve capture mode, a region of at least one nerve body formed by an anastomosis of both parasympathetic and sympathetic nerves.
2. The system of claim 1 , wherein the first separation distance is in the range of 1.5-15 mm.
3. The system of claim 1 , wherein the first separation distance is in the range of 2.5-10 mm.
4. The system of claim 2 , wherein the first combined surface area is in the range of 3 mm 2 -10 mm 2 .
5. The system of claim 3 , wherein the second combined surface area is in the range of 3 mm 2 -10 mm 2 .
6. The system of claim 1 , wherein the stimulator is configured to activate a first plurality of the electrodes to collectively form the anode or cathode.
7. The system of claim 1 , wherein the second combined surface area is in the range of 3 mm 2 -10 mm 2 .