Patent Application
20230135237
Balloon dilatation catheters are often used to treat lesions in vessels. Such catheters are typically guided to a treatment location in the vessel by a guidewire. Typically, the guidewire is a small diameter, highly flexible piece of a metal, such as stainless steel, sized to track easily through the vasculature from an access point and provide reliable guidance to the balloon catheter.
Past proposals for guidewires have been made, which typically include tapered ends and an outer coil to enhance flexibility. However, the past requirement for tapered ends on the core wire increases the cost and complexity of manufacturing the guidewire. This is because the core wire must be extensively processed prior to assembly.
Accordingly, a need is identified for a guidewire and a corresponding manner of manufacturing a guidewire that overcomes the foregoing limitations and others.
An object of the disclosure is to provide a guidewire, which can be more efficiently manufactured at a lower cost, without suffering from a lack of flexibility.
According to one aspect of the disclosure, a guidewire includes a core wire, a resin layer at least partially surrounding the core wire, and a coil wire external to the resin layer.
In one embodiment, the core wire is not tapered. Thus, the core wire has a substantially constant diameter.
In this or other embodiments, the resin layer may comprise a spirally wound tape. This spirally wound tape may comprise windings having a generally fixed pitch. Alternatively, the spirally wound tape comprises windings having a variable pitch including first windings having a first spacing at a first end of the guidewire and second windings having a second spacing away from the first end of the guidewire. The resin layer may alternatively comprise a sleeve, and the guidewire may include welded ends.
The resin layer may be melted so as to form a bond between the core wire and the coil wire, such as for example at selected locations only.
According to a second aspect of the disclosure, a guidewire includes a core wire, a resin sleeve at least partially surrounding the core wire, and a coil wire external to the resin sleeve.
The core wire is not tapered, and may have a substantially constant diameter. The resin sleeve may be melted at selected locations so as to form a bond between the core wire and the coil wire.
According to yet another aspect of the disclosure, a guidewire comprising a core wire, a resin tape at least partially surrounding the core wire, and a coil wire external to the resin tape.
The core wire may have a substantially constant diameter, and thus is not tapered. The resin tape may be spirally wound, and may include windings having a fixed pitch. Alternatively, the spirally wound tape comprises windings having a variable pitch including first windings having a first spacing at a first end of the guidewire and second windings having a second spacing away from the first end of the guidewire.
The resin layer may be melted so as to form a bond between the core wire and the coil wire, such as at selected locations only.
This disclosure also relates to a method of forming a guidewire. The method includes providing a resin layer between an inner core wire and an outer coil wire, and applying heat to at least partially melt the resin layer and bond the inner core wire to the outer coil wire.
The providing step may comprise wrapping a resin tape around the inner core wire. The wrapping may be done at a variable pitch or a substantially constant pitch. The applying step may comprise applying the heat selectively to melt only portions of the resin layer. The providing step may also comprise providing a resin sleeve over the inner core wire.
The above and further advantages of the present disclosure may be better understood by referring to the following description in conjunction with the accompanying drawings in which:
The dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be included in one functional block or element. Further, sometimes reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.
In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the presently disclosed invention(s). The disclosed embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, or structures may not have been described in detail so as not to obscure the present inventive concepts.
The invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The inventive concepts disclosed are capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
Certain features of the disclosed embodiments that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.
With reference to
As shown in the partial cross-sectional view of
As can be further understood, the intermediate layer 14 may comprise a resin tape. This resin tape may be wrapped spirally around the core wire 12. The wrapping may be done in a continuous, but non-overlapping manner, such that each successive wind lies adjacent to the previous one. This is considered to provide the resin tape with a substantially constant pitch.
Once the coil wire 16 is spirally wound around the assembly of the core wire 12, the resin tape serving as the intermediate layer 14 may be subjected to a heat treatment (e.g., indicated by area 18 in
As indicated, the heat treatment 18 may be continuously applied to the assembled guidewire 10. Again, this may be done using ultrasonic heating, but since it is not selectively applied in this embodiment in view of the variable pitch of the tape forming the intermediate layer 14, an oven could be used instead to apply the heat necessary. In either case, this heating causes the intermediate layer 14 to melt and form a bond. Yet, because of the variable spacing of the tape forming the intermediate layer 14, the flexibility and strength of the guidewire can be adjusted by varying the pitch. This is again achieved without the need for tapering the ends of the core wire 12, which remains of substantially constant diameter.
A further embodiment is shown in
The guidewire 10 and, in particular, the core wire 12 and the coil wire 16, may be fabricated of commonly used materials such as stainless steel (e.g., 304). The resin tape or sleeve forming intermediate layer 14 may also be formed of a polymer material, such as thermoplastic polyurethane (TPU) or ethylene-vinyl acetate copolymer (EVA). One or more coating or jacketing layers may also optionally be provided, which may comprise polymer materials.
Summarizing, this disclosure may be considered to relate to the following items:
Although the invention has been described in conjunction with specific embodiments, many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it embraces all such alternatives, modifications, and variations that fall within the appended claims’ spirit and scope. It is to be fully understood that certain aspects, characteristics, and features, of the invention, which are, for clarity, illustratively described and presented in the context or format of a plurality of separate embodiments, may also be illustratively described and presented in any suitable combination or sub-combination in the context or format of a single embodiment. Conversely, various aspects, characteristics, and features, of the invention which are illustratively described and presented in combination or sub-combination in the context or format of a single embodiment may also be illustratively described and presented in the context or format of a plurality of separate embodiments.
All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, the citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present disclosure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/027735 | 4/16/2021 | WO |
