Patent Application
20250135195
The present invention relates to a paddle lead according to the preamble of claim 1 as well as to a method for manufacturing such a paddle lead according to the preamble of claim 14.
Paddle leads are regularly used for spinal cord stimulation (SCS) and are placed for this purpose in the epidural space close to the spinal cord.
The term “paddle lead” originates from the flattened, paddle-like shape of these leads. Paddle leads carry an arrangement of multiple evenly or unevenly distributed electrode poles (also referred to as contact elements) on their surface for emission of electrical signals into and/or reception of electrical signals from surrounding tissue.
Paddle leads are often implanted in a surgical manner close to the height of the final site of action. For this purpose, parts of a vertebral body in this region are removed to provide necessary space for implantation.
However, it is also known to implant paddle leads in a minimally invasive way like percutaneous leads. To allow such minimally invasive implantation, it is necessary to compress the paddle lead to a delivery state in which the outer diameter of the paddle lead is reduced so that the paddle lead can be guided through an implantation catheter used for minimally invasive implantation. Once positioned at its intended site of implantation, the paddle lead is released from the implantation catheter and transferred from its (collapsed) delivery state into its (expanded) implantation state.
U.S. Pat. No. 6,205,361 B1 describes such a collapsible paddle lead. Here, a shape memory element is placed in the center of a cylindrical edge portion of the paddle lead. The shape memory element has a shape that maintains the open, paddle shape of the paddle lead and thus biases the paddle lead to the expanded implantation state.
U.S. Publication No. 2010/0082086 A1 describes a paddle lead comprising an elastically deformable elongated plate that can be releasably rolled into a substantially cylindrical form for delivery purposes. After completing the delivery, the cylinder unrolls again so that a paddle to be implanted is present.
U.S. Publication No. 2012/0283808 A1 describes a paddle lead having a frame of rigid material and comprising a spring member adapted to bias the frame to assume an implantation shape. In addition, elastic material is disposed across an interior surface area defined by the frame. In this context, a plurality of different shapes for the elastic material is disclosed in this US patent application.
U.S. Publication No. 2014/0200639 A1 describes a self-expanding lead with a plurality of expandable arms that form—in their expanded state—a complex geometry. The arms include a resilient member that is biased to flex the arms from a collapsed state to an expanded state. These resilient members form an integral part of the arms to be expanded.
The present disclosure is directed toward overcoming one or more of the above-mentioned problems, though not necessarily limited to embodiments that do.
It is an object of the present invention to provide a paddle lead for implantation in the epidural space through an insertion tool that can be easily collapsed for delivery purposes and expanded for implantation purposes and that can be easier and cheaper produced than paddle leads known from prior art.
At least this object is achieved with a paddle lead for implantation in the epidural space through an insertion tool having the claim elements of claim 1. Such a paddle lead comprises a lead body. The lead body, in turn, comprises a plurality of conductors. These conductors extend from a proximal portion of the lead body to a distal portion of the lead body. The paddle lead further comprises a paddle structure that is arranged distally of the lead body and is electrically coupled to the distal portion of the lead body. The paddle structure has a longitudinal extension direction. The paddle structure further comprises a first paddle wing and a second paddle wing. The first paddle wing and the second paddle wing are movable with respect to each other and can be present in an expanded state (implantation state) or in a collapsed state (delivery state).
A plurality of first electrode poles (contact elements) is arranged on the first paddle wing. In this context, each of the first electrode poles is electrically coupled to at least one (and typically exactly one) of the plurality of conductors. Likewise, a plurality of second electrode poles is arranged on the second paddle wing. Also in this case, each of the second electrode poles is electrically coupled to at least one (and typically exactly one) of the plurality of conductors.
The paddle structure further comprises at least one resilient element that is connected to the first paddle wing and/or the second paddle wing. In this context, the at least one resilient member biases the first paddle wing and/or the second paddle wing to the expanded state.
According to an aspect of the present invention, the at least one resilient element has a longitudinal extension direction running exclusively along the longitudinal extension direction of the paddle structure. In addition, the at least one resilient element has a wall that surrounds either alone or together with another part of the paddle structure a hollow space. In this context, the hollow space also extends exclusively along the longitudinal extension direction of the paddle structure.
Since the resilient element has a longitudinally extending shape, it can be particularly easy arranged between the first paddle wing and the second paddle wing. This facilitates manufacturing of the paddle lead. Furthermore, the hollow space surrounded by the resilient element (either alone or together with another part of the paddle structure) enables that the resilient element can be very favorably compressed and does not require much space in its compressed state. This facilitates collapsing of the first paddle wing and the second paddle wing in order to form a collapsed state of the paddle structure.
In contrast to prior art solutions in which individual elastic elements are placed side-by-side to each other, the use of the specifically designed resilient element according to an aspect of the present invention does not require complicated arrangements of different elements, but rather enables an easy insertion of the resilient element along the longitudinal extension direction of the paddle structure.
Since the resilient element already biases the first paddle wing and/or the second paddle wing to the expanded state, it is no longer necessary to provide additional spring members for transferring the paddle structure into its expanded state. Therefore, the paddle structure itself can be manufactured much cheaper than according to prior art solutions.
In an embodiment, the hollow space is accessible only by a first end of the at least one resilient element and/or a second end of the at least one resilient element, wherein the second end lies opposite the first end along the longitudinal extension direction of the at least one resilient element.
In an embodiment, the paddle structure and/or the paddle lead does not comprise a spring member other than the resilient element for biasing the first paddle wing and/or second paddle wing into its expanded state.
In an embodiment, the at least one resilient element is made from a different material than the first paddle wing and the second paddle wing. To give an example, the first paddle wing and the second paddle wing may comprise a memory shape material such as nitinol. In such a case, the at least one resilient element is not made from nitinol. To give another example, the first paddle wing and the second paddle wing may be made from a non-elastic, rigid plastic material. In such a case, the at least one resilient element is made from a different plastic material or from a resilient metallic material.
In an embodiment, the at least one resilient element is made from an elastic plastic material. Silicone and polyurethane are particularly appropriate elastic plastic materials for this purpose. Such an elastic plastic material enables a particularly easy and cheap manufacturing of the at least one resilient element. Furthermore, the overall weight of the paddle lead is reduced in case of using a plastic material for the resilient element. This enhances the user-friendliness of the paddle lead since the dead weight of the paddle lead is reduced compared to paddle leads making excessive use of metal for the individual components.
In an embodiment, the at least one resilient element has a circular or elliptical cross-section. In this embodiment, the at least one resilient element has the shape like a hose. Such a hose-like resilient element can be manufactured in a particularly simple way and can be introduced between the first paddle wing and the second paddle wing in a particularly simple manner during the manufacturing process of the paddle lead. In addition, due to the hollow space within the hose-like shape (surrounded by the wall of the resilient element), the resilient element can be compressed to a particularly small volume so that it does not impart a collapsing of the paddle lead to its collapsed delivery state.
In an embodiment, the at least one resilient element has a cross section of a segment of a circle or of a segment of an ellipse. In this embodiment, the at least one resilient element has the shape of a circumferential section of a hose. In this case, a hollow space is formed by the at least one resilient element together with another part (e.g., the first paddle wing and/or the second paddle wing) to surround a hollow space. Also in this case, a particularly favorable collapsing of the at least one resilient element is made possible. Furthermore, also such a circumferential section of a hose can be manufactured in a particularly simple and cheap way.
In an embodiment, the first paddle wing and the second paddle wing are connected with each other in the proximal portion of the first paddle wing and of the second paddle wing. At the same time, they are unconnected in a distal portion of the first paddle wing and of the second paddle wing. This results in a bifurcated structure of the first paddle wing and the second paddle wing, i.e., of the paddle structure, with freely movable distal ends of the first paddle wing and the second paddle wing. This facilitates the execution of movements during collapsing and expanding of the paddle structure.
In an embodiment, the at least one resilient element is mechanically linked with the first paddle wing and with the second paddle wing. In this embodiment, the at least one resilient element biases both the first paddle wing and the second paddle wing to their respective expanded state. In the simplest arrangements, only a single resilient element is necessary to achieve a transition of the first paddle wing and the second paddle wing from their collapsed state into their expanded state by acting upon them with an appropriate force. In this and in all other embodiments, the mechanical linkage can be realized, e.g., by gluing the resilient element to the first paddle wing and/or the second paddle wing.
In an embodiment, the paddle structure additionally comprises a ligament extending along the longitudinal extension direction of the paddle structure. In this context, the ligament is arranged between the first paddle wing and the second paddle wing. Furthermore, the at least one resilient element is also connected to the ligament. Such a ligament enables a Y-shaped collapsing and expanding of the paddle structure by a movement of the first paddle wing and the second paddle wing. The ligament may extend along the whole length of the paddle structure or only along a section thereof. Generally, the stability of the paddle structure is increased with increasing length along which the ligament extends. The ligament may be arranged centrally within the paddle structure to stabilize the first paddle wing and the second paddle wing in the same manner. Since the resilient element is connected to the ligament on the one side and the first paddle wing and/or the second paddle wing on the other side, a force transmitted by the resilient element onto the first paddle wing and/or the second paddle wing is promoted by the ligament, acting as support for the resilient member and/or the first paddle wing and/or the second paddle wing.
Since the first paddle wing and/or the second paddle wing are indirectly connected to the ligament via the at least one resilient element, it is not necessary that the first paddle wing and/or the second paddle wing are also directly connected to the ligament. In an embodiment, however, the first paddle wing and/or the second paddle wing are directly mechanically coupled with the ligament. Then, there is a direct connection between the first paddle wing and the second paddle wing on the one hand and the ligament on the other hand, as well as an indirect connection via the at least one resilient element. The kind of connection between the first paddle wing and the second paddle wing on the one hand and the ligament on the other hand influences the folding/unfolding mechanism to transfer the paddle structure from its expanded state to its collapsed state, and vice versa. The type of connection also influences the forces acting between the first paddle wing and the second paddle wing on the one hand and the ligament on the other hand. Consequently, depending on the type of connection, the elastic properties of the at least one resilient element can be adjusted to the respective needs in order to achieve an easy collapsing of the paddle structure as well as a reliable expansion of the paddle structure.
In an embodiment, the paddle structure comprises two (or more) resilient elements. In this context, the first of the two (or more) resilient elements is connected to the ligament and the first paddle wing. Likewise, the second of the two (or more) resilient elements is connected to the ligament and the second paddle wing. In this embodiment, not only a single resilient element is responsible for transferring the first paddle wing and the second paddle wing to their expanded states. Rather, two (or more) resilient elements take over this functionality.
In an embodiment, the first of the two (or more) resilient elements and the second of the two (or more) resilient elements are identical in construction. This further facilitates the overall manufacturing of the paddle lead and guarantees for equally distributed forces applied to the first paddle wing and the second paddle wing by the first resilient element and the second resilient element.
In an embodiment, the paddle structure comprises at least two resilient elements, wherein each of the at least two resilient elements extends only along a longitudinal section of the paddle structure. Furthermore, the at least two resilient elements are arranged longitudinally one behind the other. According to this embodiment, a stabilization of the paddle structure and a biasing of the first paddle wing and/or the second paddle wing to its expanded state is achieved with only section-wise arranged resilient elements. In this context, a total number of two, three or four, in particular three, resilient elements is particularly appropriate. Small gaps between the individual resilient elements typically do not have any negative impact on the expansion/collapsing properties of the paddle structure, but further reduce the required material for the elastic element. Typically, the individual resilient elements are equally spaced apart from each other and are equally distributed over the whole length of the paddle structure to achieve a good stabilization of the paddle structure as well as a proper expansion of the first paddle wing and the second paddle wing.
While this section-wise arrangement of resilient elements is typically fully sufficient for most applications, a particularly high shape stability can be achieved if the resilient element extends along the whole length of the paddle structure. In such a case, the resilient element is typically formed as a single part and not divided into individual sections that are longitudinally arranged one behind the other. Such an arrangement of the resilient element along the whole length of the paddle structure is also encompassed by an embodiment of the present invention.
In an aspect, the present invention relates to a method for manufacturing a paddle lead according to the preceding explanations. This method comprises the steps explained in the following.
A lead body is provided, wherein the lead body comprises a plurality of conductors. These conductors extend from a proximal portion of the lead body to a distal portion of the lead body. Additionally, a paddle structure is arranged distally of the lead body and is electrically coupled to the distal portion of the lead body. The paddle structure has a longitudinal extension direction. The paddle structure further comprises a first paddle wing and a second paddle wing. The first paddle wing and the second paddle wing are movable with respect to each other and can be present in an expanded state (implantation state) or in a collapsed state (delivery state).
A plurality of first electrode poles is arranged on the first paddle wing. In this context, each of the first electrode poles is electrically coupled to at least one (and typically exactly one) of the plurality of conductors. Likewise, a plurality of second electrode poles is arranged on the second paddle wing. Also in this case, each of the second electrode poles is electrically coupled to at least one (and typically exactly one) of the plurality of conductors.
The paddle structure further comprises at least one resilient element that is connected to the first paddle wing and/or the second paddle wing. In this context, the at least one resilient member biases the first paddle wing and/or the second paddle wing to the expanded state.
The at least one resilient element has a longitudinal extension direction running exclusively along the longitudinal extension direction of the paddle structure. In addition, the at least one resilient element has a wall that surrounds either alone or together with another part of the paddle structure a hollow space. In this context, the hollow space also extends exclusively along the longitudinal extension direction of the paddle structure.
In an embodiment, the hollow space is accessible only by a first end of the at least one resilient element and/or a second end of the at least one resilient element, wherein the second end lies opposite the first end along the longitudinal extension direction of the at least one resilient element.
All aspects and embodiments of the paddle electrode can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the manufacturing method. Likewise, all aspects and embodiments of the manufacturing method can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the paddle electrode.
Additional features, aspects, objects, advantages, and possible applications of the present disclosure will become apparent from a study of the exemplary embodiments and examples described below, in combination with the Figures and the appended claims.
Further details of aspects of the present invention will be explained in the following making reference to exemplary embodiments and accompanying Figures. In the Figures:
Eight first electrode poles 24 are disposed on a surface of the first paddle wing 21. Likewise, eight second electrode poles 25 are disposed on a surface of the second paddle wing 22. Each of the first electrode poles 24 is electrically coupled to a first conductor 26. For illustration purposes only, not all of the first conductors 26 are marked with the respective numeral reference.
Likewise, each of the second electrode poles 25 is electrically coupled to a second conductor 27. Also in this case, only some of the second conductors 27 are marked with the respective numeral reference.
The first conductors 26 and the second conductors 27 are guided towards the switch 23 and are then further guided through the lead body 3 to a proximal terminus of the paddle lead 1.
A hollow silicone hose 10 serving as resilient element is placed between and connected to the first paddle wing 21 and the second paddle wing 22. This silicone hose 10 extends in a longitudinal extension direction D that runs exclusively along the longitudinal extension direction L of the paddle structure 2. The silicone hose 10 biases the first paddle wing 21 and the second paddle wing 22 to their expanded states, as shown in
In the embodiment shown in
As in case of the embodiment shown in
The embodiment shown in
The first silicon hose 10 surrounds with its inner wall 12 a first hollow space 11. Likewise, the second silicon hose 14 surrounds with an inner wall 15 a second hollow space 16. The first hollow space 11 and the second hollow space 16 allow a very easy compression of the first silicon hose 10 and the second silicon hose 14.
Afterwards, the guide wire 32 is removed from the guiding catheter 31 (cf.
In a final step, plugs 100 of the paddle lead 1 are connected to a spinal cord stimulation device 5 acting as active implant (cf.
It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range, including the end points.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22157183.9 | Feb 2022 | EP | regional |
This application is the United States National Phase under 35 U.S.C. § 371 of PCT International Patent Application No. PCT/EP2023/052318, filed on Jan. 31, 2023, which claims the benefit of European Patent Application No. 22157183.9, filed on Feb. 17, 2022, the disclosures of which are hereby incorporated by reference herein in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/052318 | 1/31/2023 | WO |
