Apparatus and methods for differential stimulation of nerve fibers

An electrode assembly for surgical implantation around a nerve comprising:

• (a) a flexible supporting matrix formed substantially in the shape of a spiral helix;
• and
• (b) a plurality of spaced-apart flexible conductive ribbon electrodes secured to an array along an inner surface of the matrix, each electrode occupying only a portion of the cross-sectional periphery of the matrix and having a separate flexible conductor extending therefrom;
• the conductors being embedded in the matrix to extend from the respective ribbon electrodes to an end of the matrix;
• the matrix and electrodes generally forming a multi-turn hollow helix of a selected pitch with a free end and without a supporting core, the turns of the helix being resiliently movable with respect to each other to enable the helix to be wrapped around an unsevered nerve, the helix having a central passage therethrough of size and configuration generally conforming to the external size and configuration of the nerve, the pitch being selected such that substantially the entire nerve or any portion of it extending radially inward from its surface forming an annulus can be electrically stimulated to activate substantially all axons or a subpopulation of axons.

An electrode assembly for surgical implantation on a nerve of the peripheral or central nervous system comprising:

• (a) a flexible helically formed supporting matrix of dielectric material;
• (b) a flexible conductive electrode secured to the surface of the matrix, the electrode having front and rear surfaces and side edges, the front surface being exposed and not covered by the matrix, the electrode occupying only a portion of the cross-sectional periphery of the matrix;
• (c) at least one flexible connector connected to the electrode and extending from the matrix;
• the matrix and electrode generally forming a multi-turn hollow helix of a selected pitch and with a selected number of helical turns of the electrode, the helix having a free end and without a supporting core, the turns of the helix being resiliently movable with respect to each other to enable the helix to be wrapped around an unsevered nerve, the helix having a central passage therethrough of size and configuration generally conforming to the external size and configuration of the nerve, the pitch of the helix and the number of helical turns being selected such that the entire nerve or any portion of it extending radially inward from the surface forming an annulus can be electrically stimulated to activate substantially all axons or a subpopulation of axons.

An electrode assembly for surgical implantation on a nerve of the peripheral nervous system comprising:

• (a) a flexible supporting matrix formed substantially in the shape of a spiral helix;
• and
• (b) a plurality of spaced-apart flexible conductive ribbon electrodes secured to an arranged along an inner surface of the matrix, each electrode occupying only a portion of the cross-sectional periphery of the matrix and having a separate flexible conductor extending therefrom;
• the conductors being embedded in the matrix to extend from the respective ribbon electrodes to an end of the matrix;
• the matrix and electrode generally forming a multi-turn hollow helix of a selected pitch and with a selected number of helical turns of each electrode, the helix having a free end and without a supporting core, the turns of the helix being resiliently movable with respect to each other to enable the helix to be wrapped around an unsevered nerve, the helix having a central passage therethrough of size configuration generally conforming to the external size and configuration of the nerve, the pitch of the helix and the number of helical turns of each electrode being selected such that substantially the entire nerve or any portion of it extending radially inward from the surface forming an annulus can be selectively stimulated to activate substantially all axons or a subpopulation of axons.

A device for treating a condition or disease treatable by electrical stimulation of a peripheral nerve comprising:

• (a) a helical electrode assembly comprising:
• (i) a flexible helically formed supporting matrix of dielectric material;
• (ii) at least one flexible conductive electrode secured to the surface of the matrix, the electrode having front and rear surfaces and side edges, the front surface being exposed and not covered by the matrix, the electrode occupying only a portion of the cross-sectional periphery of the matrix;
• and
• (iii) at least one flexible connector connected to the at least one electrode and extending from the matrix;
• the matrix and the at least one electrode generally forming a multi-turn hollow helix of a selected pitch and with a selected number of helical turns of each electrode, the helix having a free end and without a supporting core, the turns of the helix being resiliently movable with respect to each other to enable the helix to be wrapped around an unsevered peripheral nerve whose stimulation treats the disease or condition, the helix having a central passage therethrough of size and configuration generally conforming to the external size and configuration of the peripheral nerve, the pitch of the helix and the number of helical turns being selected such that the entire peripheral nerve or any portion of it extending radially inward from the surface forming an annulus can be electrically stimulated to activate substantially all axons or a subpopulation of axons of the nerve;
• (b) a controllable current or voltage source in electrical contact with the at least one flexible connector;
• and
• (c) a controller for controlling the current or voltage source so that an electric field is created by the at least one electrode to treat the disease or condition.

An electrode assembly for implantation on a nerve comprising:

• (a) a flexible supporting matrix of dielectric material, the matrix forming a pair of spaced-apart and oppositely directed helical portions, each helical portion extending circumferentially at least 360° and less than 720°;
• (b) a flexible conductive electrode secured to an inner surface of one of the helical portions, the flexible conductible electrode forming a helix of selected pitch;
• and
• (c) a flexible connector connected to the electrode and extending from the matrix for connection to an electronic device;
• the assembly having a central passage longitudinally through and sized to conform to the external dimension of the nerve, whereby a tool can be inserted in the passage to expand the helical portions to open a lateral passage along the full length of the assembly to enable the assembly to be fitted over and closed upon the nerve;
• the pitch of the helix being selected such that the entire nerve or any portion of it extending radially inward from its surface forming an annulus can be electrically stimulated to activate substantially all axons or a subpopulation of axons.

A kit comprising:

• (a) an electrode assembly for implantation on a nerve comprising:
• (i) a flexible supporting matrix of dielectric material, the matrix forming a pair of spaced-apart and oppositely directed helical portions, each helical portion extending circumferentially at least 360° and less than 720°;
• (ii) a flexible conductive electrode secured to an inner surface of one of the helical portions, a flexible conductive electrode forming a helix of defined pitch;
• and
• (iii) a flexible connector connected to the electrode and extending from the matrix for connection to an electronic device;
• the pitch of the helix being selected such that the entire nerve or any portion of it extending radially inward from its surface forming an annulus can be electrically stimulated to activate substantially all axons or a subpopulation of axons;
• and
• (b) an insertion tool having a portion which is fitted and expanded within the central passage to expand the helical portion and thereby to form a laterally open passage along the length of the assembly so that the assembly can be fitted over and closed upon the nerve upon removal of the tool portion.