BACKGROUND OF THE INVENTION

Embodiments herein generally relate to stimulation therapy, such as spinal cord stimulation (SCS) therapy, and more particularly to systems and methods including a paddle lead having a multi-dimensional electrode array.

Stimulation systems are devices that generate electrical pulses and deliver the pulses to tissue to treat a variety of disorders. Neurostimulation (NS) is the stimulation of nerve tissue, such as the spinal cord or brain. SCS is a common type of neurostimulation. In SCS, electrical pulses are delivered to nerve tissue in the spine typically for the purpose of chronic pain control. While a precise understanding of the interaction between the applied electrical energy and the nervous tissue is not fully appreciated, it is known that application of an electrical field to spinal nervous tissue can be used to mask certain types of pain transmitted from regions of the body associated with the stimulated nerve tissue. SCS may have applications other than pain alleviation as well.

NS systems, including SCS systems, generally include a pulse generator and one or more leads electrically coupled to the pulse generator. A lead includes a lead body having insulative material and an electrode array that is arranged at an end of the lead body. The electrodes are electrically coupled to the pulse generator through wire conductors. The lead is implanted within an individual's body such that the electrode array is proximate to nervous tissue (e.g., within epidural space of a spinal cord) to deliver the electrical pulses. The pulse generator may also be implanted within the individual and may be programmed (and re-programmed) to provide the electrical pulses in accordance with a designated sequence.

Typically, there are two types of leads that can be used. The first type is a percutaneous lead, which has a rod-like shape and includes electrodes spaced apart from each other along a single axis. The second type of lead is a paddle lead. A paddle lead has an elongated multi-dimensional body at an end of the lead that has a thin, rectangular-like shape (i.e., paddle-like shape). Although the percutaneous lead may include only one row or column of electrodes, the paddle lead includes an array of electrodes that are spaced apart from each other along more than one dimension. The wire conductors that deliver the electrical signals from the pulse generator are electrically connected to certain electrodes within the paddle-like body (hereinafter referred to as the “lead paddle”).

Although paddle leads have been implemented successfully, some challenges remain. Fabrication of paddle leads can be complex. Also, the electrical connections within a paddle lead can be subject to failure over time for a variety of reasons.

In addition to the above, the paddle bodies can be rigid or semi-rigid. In SCS, the lead paddle is typically positioned within the epidural space adjacent to the dura of the spinal cord. In some instances, the size of the epidural space and the dimensions of the lead paddle cause the lead paddle to press against the spinal cord. If the compression is substantial, it may cause unwanted consequences, such as a tingling sensation, pain, partial paralysis, or even complete paralysis of the legs.

SUMMARY

In an embodiment, a stimulation lead is provided. The stimulation lead includes an elongated lead body having distal and proximal ends and wire conductors extending therebetween. The stimulation lead also includes a lead paddle having a multi-dimensional array of electrodes positioned along a contact side of the lead paddle. The electrodes are electrically coupled to the wire conductors. The lead paddle includes a paddle body and a conductor organizer disposed within the paddle body. The conductor organizer has multiple channels extending along the lead paddle. The channels receive the wire conductors and retain the wire conductors in a designated arrangement with respect to the lead paddle. The conductor organizer has openings to the channels. The wire conductors extend through the openings and are terminated to the respective electrodes.

In some aspects, the openings are positioned adjacent to respective electrodes of the multi-dimensional array of electrodes.

In some aspects, the conductor organizer includes a plurality of tubes that are connected to one another side-by-side. The tubes define the channels. In other aspects, the tubes are not positioned side-by-side. For example, adjacent tubes may be spaced apart by a gap.

In some aspects, the channels extend parallel to one another for at least a portion of a length of the conductor organizer. In particular aspects, the channels extend parallel to one another for the entire length of the conductor organizer.

In some aspects, the lead paddle includes an inner frame having opposite first and second side surfaces and a flexible layer secured to the first side surface of the inner frame. For example, the flexible layer may be overmolded with respect to the inner frame. The flexible layer defines a portion of the contact side of the lead paddle. The inner frame may be more rigid than the flexible layer. The channels of the conductor organizer extend along and parallel to the second side surface of the inner frame.

In some aspects, the inner frame includes frame windows and the flexible layer includes layer windows that align with the frame windows to form conductor passages. The wire conductors extend through the conductor passages and are mechanically and electrically coupled to the respective electrodes. For example, the wire conductors may be welded or soldered to the electrodes.

In some aspects, the electrodes are arranged in columns that extend longitudinally along the lead paddle. The columns are separated by a spacing. The channels of the conductor organizer may extend along the spacing between the columns of the electrodes.

Optionally, the columns include first and second columns that are adjacent to one another. The channels of the conductor organizer may extend along the spacing between the first and second columns, wherein at least one of the wire conductors that is received by the channels of the conductor organizer is terminated to one of the electrodes of the first column and at least one of the wire conductors that is received by the channels of the conductor organizer is terminated to one of the electrodes of the second column.

In some aspects, the openings of the conductor organizer include at least one side opening and at least one distal opening. The distal opening is at an end of the conductor organizer. The side opening is spaced apart from the at least one distal opening of the conductor organizer.

In some aspects, each of the channels receives only one of the wire conductors. In other aspects, however, the channels may be sized and shaped to receive more than one wire conductor.

In some aspects, the conductor organizer includes a plurality of conductor organizers. Each of the conductor organizers may receive a plurality of the wire conductors.

In an embodiment, a method is provided that includes positioning electrodes along at least one body layer to form a multi-dimensional array and positioning a conductor organizer along the at least one body layer. The conductor organizer has multiple channels extending therethrough. The method also includes inserting wire conductors into the channels of the conductor organizer. The conductor organizer retains the wire conductors in a designated arrangement with respect to the at least one body layer. The conductor organizer has openings to the channels. The wire conductors extend through the openings (e.g., side opening and/or distal openings). The method also includes electrically coupling the wire conductors to respective electrodes.

In some aspects, the at least one body layer is a multi-layered structure that includes conductor passages that align with respective electrodes. The method may also include directing the wire conductors through the conductor passages.

In some aspects, the at least one body layer has a first lateral section and a second lateral section. The method may also include providing a lead body having distal and proximal ends. The lead body also includes first and second windings of the wire conductors. The first winding is wrapped in a first direction along the lead body. The second winding is wrapped in a second direction along the lead body. The method also includes positioning the first and second windings of the wire conductors onto the at least one body layer. The first winding and the second winding are positioned in a splayed configuration such that the first winding extends toward the first lateral section and the second winding extends toward the second lateral section.

In some aspects, the electrodes are arranged in columns. The columns may be separated by a spacing. The channels of the conductor organizer may extend along the spacing between the columns of the electrodes.

In an embodiment, a stimulation lead is provided that includes a lead paddle having a contact side that includes electrodes. The lead paddle has a first lateral section and a second lateral section. The stimulation lead also includes a lead body having a distal and proximal ends. The lead body includes first and second windings of wire conductors. The first winding is wrapped in a first direction along the lead body. The second winding is wrapped in a second direction along the lead body. The first winding and the second winding project from the lead body in a splayed configuration such that the first winding extends toward the first lateral section of the lead paddle and the second winding extends toward the second lateral section of the lead paddle.

In some aspects, a bonding material holds the wire conductors of the first winding side-by-side to form a first conductor layer and a bonding material holds the wire conductors of the second winding side-by-side to form a second conductor layer. The first and second conductor layers project from the leady body in the splayed configuration. Optionally, the bonding material for the first and second conductor layers is at least partially removed after a distance from the lead body.

In some aspects, the lead paddle includes a paddle body and first and second conductor organizers disposed within the paddle body. The first and second conductor organizers have channels extending along the lead paddle. The channels receive the wire conductors and retain the wire conductors in a designated arrangement with respect to the lead paddle. The first conductor organizer is within the first lateral section, and the second conductor organizer is within the second lateral section.

In some aspects, the lead body has only a single lumen. The first winding of the wire conductors is wrapped about the lumen in a first direction and the second winding of the wire conductors is wrapped about the first winding and the lumen in a second direction.

In an embodiment, a method is provided that includes providing a multi-layered structure having a first lateral section and a second lateral section. The multi-layered structure has electrodes along the multi-layered structure that form a multi-dimensional array. The method also includes providing a lead body having distal and proximal ends. The lead body also includes first and second windings of wire conductors. The first winding is wrapped in a first direction along the lead body, and the second winding is wrapped in a second direction along the lead body. The method also includes positioning the first and second windings of the wire conductors onto the multi-layered structure. The first winding and the second winding are positioned in a splayed configuration such that the first winding extends toward the first lateral section of the multi-layered structure and the second winding extends toward the second lateral section of the multi-layered structure.

In an embodiment, a stimulation lead is provided that includes an elongated lead body having wire conductors extending between distal and proximal ends of the lead body. The stimulation lead also includes a lead paddle coupled to the distal end of the lead body and having a contact side that is configured to face tissue. The contact side has a multi-dimensional array of electrodes that are electrically coupled to the wire conductors. The lead paddle extends lengthwise along a longitudinal axis, wherein the lead paddle has a neutral plane extending therethrough with a neutral longitudinal force envelope (NLFE) surrounding the neutral plane. The lead paddle includes an inner frame having opposite first and second side surfaces. The first side surface faces the contact side. The lead paddle also includes a flexible layer secured to the first side surface of the inner frame and defining a portion of the contact side of the lead paddle. The wire conductors extend along the second side surface of the inner frame and at least a portion of the wire conductors and inner frame are positioned to extend along the NLFE such that, when the lead paddle is flexed transverse to the longitudinal axis by a predetermined amount, the portion of the wire conductors and inner frame within the NLFE experience no more than a predetermined limit of tensile stress or compression stress.

In some aspects, centers of the wire conductors are spaced from the second side surface of the inner frame by a distance that is less than twice a diameter of the wire conductors.

In some aspects, the wire conductors do not cross over one another and the wire conductors do not cross over the electrodes, except for the respective electrodes that the wire conductors are electrically coupled to.

In some aspects, the lead paddle also includes a backing layer. The inner frame is disposed between the flexible layer and the backing layer. The wire conductors extend through the backing layer.

In some aspects, the backing layer includes a back side of the lead paddle that is generally opposite the contact side. The backing layer defines raised portions and recessed portions separated by the raised portions along the back side. The wire conductors extend through the recessed portions.

In some aspects, the flexible layer and the backing layer are shaped to form thin sections of the lead paddle and thick sections of the lead paddle. The thin sections have a thickness of the lead paddle that is less than a thickness of the thick sections. The wire conductors extend through the thin sections.

In some aspects, the inner frame and the flexible layer are a pre-formed multi-layered structure. The backing layer is molded to the pre-formed multi-layered structure.

In some aspects, the inner frame includes frame windows and the flexible layer includes layer windows that align with the frame windows to form conductor passages. The wire conductors extend through the conductor passages and are mechanically and electrically coupled to the electrodes.

In some aspects, the electrodes include projections that extend through the flexible layer and couple to the inner frame. The projections are pierced through the flexible layer.

In some aspects, the inner frame includes grooves or channels that align with and extend parallel to the wire conductors.

In some aspects, the lead paddle includes a conductor organizer that has multiple channels extending through the lead paddle. The channels receive the wire conductors. The conductor organizer is configured to retain the wire conductors in a designated arrangement with respect to the lead paddle. For example, the conductor organizer is configured to retain the wire conductors in a designated arrangement with respect to the electrodes. The conductor organizer extends through the NLFE.

In some aspects, the lead paddle has a first lateral section and a second lateral section. The lead body also includes first and second windings of the wire conductors. The first winding is wrapped in a first direction along the lead body. The second winding is wrapped in a second direction along the lead body. The first winding and the second winding project from the lead body in a splayed configuration such that the first winding extends toward the first lateral section of the lead paddle and the second winding extends toward the second lateral section of the lead paddle.

In an embodiment, a method is provided that includes providing a multi-layered structure having an inner frame and a flexible layer secured to the inner frame. The inner frame is more rigid than the flexible layer. The method also includes positioning electrodes along the flexible layer to form a multi-dimensional array. The electrodes extend through the flexible layer and couple to the inner frame. The method also includes positioning the wire conductors along the second side surface of the inner frame. The method also includes molding a backing layer to the multi-layered structure to form a lead paddle extending lengthwise along a longitudinal axis. The lead paddle has a neutral plane extending therethrough with a neutral longitudinal force envelope (NLFE) surrounding the neutral plane, wherein at least a portion of the wire conductors and inner frame are positioned to extend along the NLFE such that, when the lead paddle is flexed transverse to the longitudinal axis by a predetermined amount, the portion of the wire conductors and inner frame within the NLFE experience no more than a predetermined limit of tensile stress or compression stress.

In some aspects, the multi-layered structure includes conductor passages that align with respective electrodes. The method also includes directing the wire conductors through the conductor passages and positioning the wire conductors adjacent to the respective electrodes. The method also includes mechanically and electrically coupling the wire conductors to the respective electrodes.

In some aspects, the method also includes positioning a conductor organizer along the inner frame of the multi-layered structure. The conductor organizer has respective channels that receive the wire conductors.

In some aspects, the wire conductors do not cross over one another and the wire conductors do not cross over the electrodes, except for the respective electrodes that the wire conductors are terminated to.

In some aspects, the multi-layered structure has a first lateral section and a second lateral section. The method also includes providing a lead body having distal and proximal ends. The lead body also includes first and second windings of the wire conductors. The first winding is wrapped in a first direction along the lead body. The second winding is wrapped in a second direction along the lead body. The method also includes positioning the first and second windings of the wire conductors onto the multi-layered structure. The first winding and the second winding project from the lead body in a splayed configuration such that the first winding extends toward the first lateral section of the multi-layered structure and the second winding extends toward the second lateral section of the multi-layered structure.

In some embodiments, an implantable stimulation lead for stimulation of neural tissue of a patient is provided. The lead comprises: an elongated lead body having distal and proximal ends and wire conductors extending therebetween; and a paddle structure adapted to be implanted adjacent to neural tissue for electrical stimulation, the paddle structure comprising a flexible polymer body, electrodes arranged in a multi-dimensional pattern and positioned along a contact side of the flexible polymer body, and a plurality of sets of microtubes with each microtube having an inner lumen; wherein (1) the electrodes are electrically coupled to the wire conductors of the lead body through wires positioned within the inner lumens of the plurality of sets of microtubes, (2) each set of microtubes are positioned to extend along the paddle structure, and (3) the polymer body of the paddle structure flexes transversely about its longitudinal axis and the plurality of sets of microtubes are arranged generally parallel to the longitudinal axis.

A method of fabricating an implantable stimulation lead for provision of electrical stimulation to tissue of a patient is provided. The method comprises: providing a paddle structure adapted to be implanted adjacent neural tissue for electrical stimulation, the paddle structure comprising a flexible polymer body; providing electrodes arranged in a multi-dimensional pattern and positioned along a contact side of the flexible polymer body; providing a plurality of sets of microtubes with each microtube having an inner lumen on the flexible polymer body; routing a wire through each respective microtube of the plurality of sets of microtubes; and electrically coupling the wires within plurality of sets of microtubes to respective electrodes positioned along a contact side of the flexible polymer body, wherein the polymer body of the paddle structure flexes transversely about its longitudinal axis and the plurality of sets of microtubes are arranged generally parallel to the longitudinal axis.

In some embodiments, a method of fabricating a stimulation lead for electrical stimulation of tissue of a patient is provided. The method comprises: providing a paddle structure adapted to be implanted adjacent neural tissue for electrical stimulation, the paddle structure comprising a flexible polymer body; providing electrodes arranged in a multi-dimensional pattern and positioned along a contact side of the flexible polymer body; providing a plurality of sets of microtubes on the flexible polymer body, each microtube having an inner lumen; providing a lead body comprising a first plurality of conductor wires and a second plurality of conductor wires extending between a proximal and distal end of the lead body; routing a conductor wire through the inner lumen of each respective microtube of the plurality of sets of microtubes, wherein the routing comprising separating a first backing layer for the first plurality of conductor wires and a second backing layer for the second plurality of conductors wires at a distal end of the lead body to couple the first plurality of conductor wires to electrodes on a first side of the paddle structure and to couple the second plurality of conductor wires to electrodes on a second side of the paddle structure; and electrically coupling the conductor wires within plurality of sets of microtubes to respective electrodes positioned along a contact side of the flexible polymer body, wherein the polymer body of the paddle structure flexes transversely about its longitudinal axis and the plurality of sets of microtubes are arranged generally parallel to the longitudinal axis.

In some embodiments, an elongated lead body is provided having distal and proximal ends. The lead body comprises a first plurality of wire conductors and a second plurality of wire conductors extending between the distal and proximal ends, wherein the first plurality of conductor wires are bonded to a first backing layer and the second plurality of conductor wires are bonded to a second backing layer. The lead body comprises a paddle structure adapted to be implanted adjacent to neural tissue for electrical stimulation, the paddle structure comprising a flexible polymer body, electrodes arranged in a multi-dimensional pattern and positioned along a contact side of the flexible polymer body, and a plurality of sets of microtubes with each microtube having an inner lumen. The first and second plurality of conductor wires extend beyond the first backing layer and second backing layer at a distal end of the lead body and are positioned within the inner lumens of the plurality of sets of microtube of the paddle structure. The electrodes are electrically coupled to the first and second plurality of wire conductors, (2) each set of microtubes are positioned to extend along the paddle structure. The polymer body of the paddle structure flexes transversely about its longitudinal axis and the plurality of sets of microtubes are arranged generally parallel to the longitudinal axis.

