Suction catheter with woven marking tape and improved visibility under fluoroscopy

Abstract

A catheter (10) for treating an aneurysm is disclosed. The catheter (10) includes a liner (12) having a proximal end, a distal end, an outer surface, and a lumen extending along a longitudinal axis A from the proximal end to the distal end. A braid (22) is disposed on an outer surface of the liner (12) and extends from a proximal end to a distal end of the liner. The braid (22) comprises a plurality of wires (24, 26), where a first portion (24) of the wires is made of tungsten and a second portion (26) of the wires is made of a different material. A sheath (28) is disposed about the braid and extends from the proximal end to the distal end. The braid (22) may include at least four axial sections, wherein the first distal section has a knit rate of about 330 needles / inch ("ppi").

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 447,523, filed on February 22, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to devices and methods for removing acute blockages from blood vessels during endovascular medical treatment. More particularly, the present disclosure relates to a suction evacuation catheter into which an object or objects can be retrieved. Background Art

[0004] In the case of patients suffering from conditions such as acute ischemic stroke (AIS), myocardial infarction (MI) and pulmonary embolism (PE), clot removal aspiration catheters and devices are often used in mechanical thrombectomy for endovascular intervention. Accessing the neurovascular bed using conventional techniques is challenging because the target vessel is relatively small in diameter, distal to the insertion site, and highly tortuous. These catheters are typically very long and must follow the configuration of the vessel in all branches and windings. Conventional devices are typically too large in size, lack the deliverability and flexibility required to traverse particularly tortuous vessels, or are unable to effectively remove clots when delivered to the target site.

[0005] Therefore, there remains a need for improved catheter designs that improve upon current methods for increasing catheter lateral flexibility to improve catheter trackability. The disclosed design is intended to provide an improved catheter having the improved deliverability and flexibility required for navigating particularly tortuous vessels. The disclosed design also provides a catheter having a braided metal wire reinforcement layer that improves catheter visibility under fluoroscopy while remaining flexible (including at the distal end of the catheter) to improve catheter trackability when navigating tortuous vessels.

[0006] In order for angiocatheters to reach their target sites, catheters are manufactured so that at their proximal end, the catheter is designed to be relatively rigid and gradually becomes less rigid / more flexible at the distal end of the catheter. This is primarily achieved by using harder materials (Rockwell hardness from 180 to 90) at the proximal end and softer materials (Rockwell hardness from 180 to 90) at the distal end. <35D to Shore hardness 72A to 30A) as the outer sheath material. Vascular catheters are navigated within blood vessels (such as, for example, in human anatomy) with the help of fluorescent imaging using x-rays. However, the polymer material of the catheter does not attenuate x-rays well, so the catheter is not visible under fluoroscopy. None of the metal parts of the catheter body, such as braided or wound wire reinforcement layers, have significant radiopacity. Stainless steel grades, such as 304, 316, 404, etc., are commonly used as braiding materials. However, stainless steel has moderate radiopacity, but does not reach a level that is clinically acceptable as a marker band. For this reason, conventional catheters incorporate a highly x-ray attenuating metal marker, called a marker band, at the distal-most tip of the catheter. Figure 9 Figure 2 shows what a conventional catheter looks like under fluoroscopy. Due to the marker band, only the distal tip of a conventional catheter is visible under fluoroscopy, and this only shows where the distal tip of the catheter is located within the vasculature. Therefore, medical practitioners rely solely on physical feedback from conventional catheter designs to help them navigate such devices within the vasculature.

[0007] For most catheter designs, the metal of choice is a stainless steel grade (304, 316, 404, etc.). Stainless steel has moderate radiopacity, but does not reach a clinically acceptable level of functionality as a marker band. These braided wires can be made of a more radiopaque material, such as platinum, but platinum is not very resistant to deformation. Catheters with platinum braids do not return well to their original shape after deformation, but rather are susceptible to plastic deformation. Therefore, catheters with platinum braids do not have the mechanical structure to function as vascular catheters. Summary of the Invention

[0008] The catheter according to the present disclosure allows visualization of the entire length of the catheter. The catheter allows the medical practitioner to adjust their navigation technique using visual cues. Thus, as all regions of the catheter are traversed through the anatomy, the medical practitioner can adjust how they push and pull the catheter and accessories based on visible feedback along the entire length of the catheter, which allows visualization of how the catheter's radiopaque shaft bends at any point along the shaft.

[0009] Because the entire length of the catheter according to the present disclosure is visible under fluoroscopy, there is no need to provide a separate ridged marker band at the distal end of the catheter. The distal tip of the catheter according to the present disclosure is radiopaque due to the compression of the braid at the distal end of the catheter. This structure allows for a radiopaque tip that is also flexible at the distal end of the catheter. Therefore, the catheter according to the present disclosure provides better and more seamless navigation through tortuous anatomical structures. The distal end of the catheter according to the present disclosure does not include a separate radiopaque marker band, but instead relies on a continuous section of the braid component itself to provide the catheter design. Therefore, the catheter according to the present disclosure allows for visualization of the entire length of the catheter, and even greater visualization at the distal end, without the need for a separate rigid marker band. In some examples, the rigid marker band of a conventional catheter may separate from the rest of the catheter during use of the catheter and remain in the vasculature.

[0010] In some examples, a catheter for treating an aneurysm according to the present disclosure is disclosed. The catheter may include a liner having a proximal end, a distal end, an outer surface, and a lumen extending from the proximal end to the distal end along a longitudinal axis A. A braid is disposed on the outer surface of the liner and extends from the proximal end to the distal end of the liner. The braid includes a plurality of wires, wherein a first portion of the wires is made of tungsten and a second portion of the wires is made of a different material. A sheath is disposed around the braid and extends from the proximal end to the distal end. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other aspects of the present disclosure will be further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate similar structural elements and features in the various figures. The drawings are not necessarily drawn to scale, with emphasis instead being placed on illustrating the principles of the present disclosure. The drawings depict one or more specific implementations of the present invention by way of example only and not limitation.

[0012] Figure 1 is a perspective view of a catheter according to the present disclosure;

[0013] Figure 2 is a top view of a catheter according to the present disclosure showing a core used during manufacture;

[0014] Figure 3 is a partially exploded view, with parts removed, showing a segment of an outer jacket surrounding a metal braid that surrounds an inner liner;

[0015] Figure 4 is a view of a metal braid of a catheter having segments of varying braid density;

[0016] Figure 5is a top view of the catheter with some components removed;

[0017] Figure 6A It is a partial top view of a prior art catheter, without showing the outer sheath;

[0018] Figure 6B Is from Figure 6A 6B is a cross-sectional view showing a hollow integral marker band at the distal end of the catheter;

[0019] Figure 7 is a partial top view of the distal end of a catheter according to the present disclosure, without showing the outer sheath;

[0020] Figure 8A and Figure 8B is a picture of a catheter according to the present disclosure, the catheter being shown within a blood vessel; and

[0021] Figure 9 is a picture of a catheter according to the prior art, which is shown inside a blood vessel. DETAILED DESCRIPTION

[0022] The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or its application and uses. Although the present disclosure is described in many cases in the context of treating intracranial arteries, the present disclosure can also be used in other body passages as described above.

[0023] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows the part or assembly of components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of ±20% of the recited value, for example, "about 80%" can refer to a range of values ​​from 61% to 99%.

[0024] As discussed herein, a "patient" or "subject" can be a human or any animal. It should be understood that the animal can be of any suitable type, including but not limited to mammals, veterinary animals, livestock animals, or pet animals. For example, the animal can be a laboratory animal specifically selected to have certain characteristics similar to humans, such as rats, dogs, pigs, monkeys, etc.

[0025] "Comprising" or "containing" or "including" means that at least the named compound, element, particle or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if other such compounds, materials, particles, method steps have the same function as those named.

[0026] It should also be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as "about" or "approximately" one particular value and / or "about" or "approximately" another particular value. When such a range is expressed, other illustrative examples include from the one particular value and / or to the other particular value.

[0027] Accessing the cerebral, coronary, and pulmonary vasculature involves the use of a number of commercially available products and conventional procedural steps. Access products such as guidewires, guide catheters, angiographic catheters, and microcatheters are described elsewhere and are commonly used in catheterization laboratory procedures. The following description assumes that these products and methods are used in conjunction with the devices and methods of the present disclosure and do not require detailed description.

[0028] Documents incorporated by reference into this patent application are considered an integral part of this application, unless any terms defined in these incorporated documents conflict with definitions explicitly or implicitly given in this specification, only the definitions in this specification shall prevail.

[0029] A catheter according to the present disclosure includes: an inner lumen lining comprising a first polymer material; a braided metal wire sheath comprising a plurality of metal wires; and an outer lining comprising a second polymer material, which may be the same as or different from the first polymer material. A portion of the plurality of metal wires is made of tungsten, and a portion of the plurality of metal wires is made of stainless steel. The tungsten is visible under fluoroscopy and provides visual feedback to the user of the entire length of the catheter when tracking the catheter in the vasculature. In addition, the braid is made with a higher braid density (pic count) near the distal end to provide increased visibility at the distal end, but without the disadvantages of using a rigid marker band.

[0030] Now refer to Figures 1 to 5 and Figure 7Catheter 10 is used for navigating within a body lumen. Catheter 10 includes a core or liner 12, a braid 22, and an outer sheath 28. Catheter 10 has a proximal end 14 and a distal end 16. Core 12 has an outer surface 18, an inner lumen 20 extending from proximal end 14 to distal end 16, and a longitudinal axis A. Braid 22 is disposed on outer surface 18 of liner 12 and extends from proximal end 14 to distal end 16 of liner 12. Braid 22 includes a plurality of wires 24 and 26. A first portion 24 of the wires is made of tungsten, and a second portion 26 of the wires is made of a different material, such as stainless steel. Tungsten wire 24 can be made of tungsten and its alloys, such as WRe, WCr, WTa, WMo, and WTi. Stainless steel wire can be made of, for example, stainless steel grades 304, 304V, 316, and 404. Sheath 28 is disposed around braid 22 and extends from proximal end 14 to distal end 16.

[0031] Refractory metals / alloys, such as tungsten (W), MoRe, NbHf, NbW, VTa, or more generally metals from period 6 of the periodic table, have very high radiopacity. Many of these alloys are so hard that, when incorporated into a braid, they form a mechanically strong metal skeleton with very elastic or resilient properties. That is, a catheter having braided wires resists radial loads when constructed into a tubular braid, wherein at least a portion of the braided wires is made of period 6 metals. Catheters according to the present disclosure incorporate such metals as some of the braided wires to achieve clinically relevant radiopacity. Further increases in radiopacity are achieved by compressing the braid to an extent that the braided wire diameter will allow a braided marker band to form in the most distal section of the braid.

[0032] The first portion 24 of wires is approximately half of the total number of wires, and the second portion 26 of wires is also approximately half of the total number of wires. In one example of the present disclosure, the first portion 24 of wires includes eight wires, and the second portion 26 of wires includes eight wires.

[0033] In one example of the present disclosure, the liner 12 is made of PTFE. In one example of the present disclosure, the jacket 28 is made of a polymer material. Figure 2 and Figure 5 As shown, the sheath 28 is composed of a plurality of segments 40, 42, 44, 46, 48, 50, 52, and 54. In one example, eight sheaths are combined to form the sheath 28. A strain relief section 56 is connected at its proximal end to the segment 54. The strain relief section 56 is connected to a luer connector 58 as is known in the art.

[0034] The braid 22 has a plurality of different braid rates along the longitudinal axis A of the braid 22. In one example, the braid 22 has at least four axial segments 32, 34, 36, 38 extending from the distal end 16 to the proximal end 14. The at least four axial segments include a first distal-most segment 32, a second distal segment 34 adjacent to the first distal-most segment, a third distal segment 36 adjacent to the second distal segment, and a fourth proximal-most segment 38 adjacent to the third distal segment 36. The second distal segment 34 is between the first distal segment 32 and the third distal segment 38. The third distal segment 36 is between the second distal segment 34 and the fourth distal segment 38. The fourth proximal-most segment 38 is adjacent to the third distal segment 36.

[0035] Each braided segment 32, 34, 36, 38 has a different braid rate. The first, most distal braided segment 32 has a braid rate of approximately 330 stitches per inch ("ppi"). The first distal braided segment 32 has an axial length of approximately 0.010 inches to approximately 0.039 inches. The second distal braided segment 34 has a braid rate of approximately 105 ppi. The second distal braided segment 34 has an axial length of approximately 7.87 inches. The third distal braided segment 36 has a variable braid rate of approximately 105 ppi to approximately 195 ppi. The third distal braided segment 36 has a variable braid rate of approximately 105 ppi adjacent to the proximal end of the third distal segment to approximately 195 ppi adjacent to the distal end of the third distal segment. The third distal braided segment 36 has a variable braid rate that continuously transitions from the proximal end of the third distal segment to the distal end of the third distal segment. The braid third distal section 36 has an axial length of approximately 7.87 inches. The braid fourth proximal section 38 has a braid rate of approximately 195 ppi. The braid fourth proximal section 38 has an axial length of approximately 44.0 inches.

[0036] Now refer to Figure 7 , the distal end 16 of the catheter 10 is shown. The first braided segment 32 is shown, and only a portion of the outer sheath 28 is shown so that segments 32 and 34 of the braid 22 are visible. The distal end of the distal-most segment 32 of the braid is spaced a distance X from the distal end of the catheter. The distal end of the catheter is composed of the core 12 and the outer sheath 28 (specifically, the segment 40 of the outer sheath 28) within the distance X, and is free of braid reinforcement. The distal segment of the braid 22 includes the first braid segment 32. Because the distal segment of the catheter 10 does not have a rigid marker band, but instead has a flexible braid segment 31, the distal end 16 of the catheter 10 is relatively flexible and atraumatic. The distance X is about 0.025 cm to about 0.050 cm, or about 0.010 inches to about 0.020 inches.

[0037] In an example of the present disclosure, the catheter 10 has an inner diameter of approximately 0.092 inches from its proximal end 14 to its distal end 16. In an example of the present disclosure, the catheter 10 also has an outer diameter that tapers from approximately 0.108 inches at the proximal end 14 to approximately 0.101 inches at the distal end 16. In an example of the present disclosure, the catheter 10 can have various working lengths, such as, for example, approximately 114 cm, or approximately 122 cm, or approximately 130 cm, or approximately 135 cm. The catheter 10 can also have a hydrophilic coating on its inner diameter that extends from the distal end 16 to the proximal end for a length of approximately 50 cm.

[0038] Now refer to Figure 8A and Figure 8B , shows a picture of a catheter 10 according to the present disclosure under fluoroscopy within a blood vessel 30. As can be seen, the distal end 16 of the catheter is visible due to the increased braiding of the braid 22 at the first distal-most section 32 of the braid 22. Additionally, because the braid 22 is partially composed of tungsten wire, the entire length of the catheter 10 can be seen in outline under fluoroscopy. Figure 8A 、 Figure 8B and Figure 9 Can be seen as a blurred shadow. Figure 8A The relative sizes are shown by the circle labeled 7. Circle 7 has a diameter of approximately 0.949 inches. Figure 9 A conventional catheter is shown under fluoroscopy within a blood vessel 30. Figure 9 The conventional catheter cannot be seen, but the distal end 116 of the conventional catheter can be seen.

[0039] Now refer to Figure 6A and Figure 6B , illustrates the distal end of a prior art catheter 100. The catheter 100 has a core 102, a braid 104 surrounding the core, and a sheath 106 surrounding the braid. The catheter 100 also has a marker band 108 at the distal end of the catheter and embedded between the core 102 and the sheath 106. The marker band 108 is made of a material that is radiopaque under fluoroscopy, such as platinum / iridium, tantalum, or gold, and typically has an axial length of about 0.5 mm to about 2 mm. Figure 6A and Figure 6BAs shown, the marker band 108 is a rigid, one-piece hollow annular band disposed about the core 102 and radially within the sheath 106. Therefore, the marker band 108 located at the distal end of the catheter is not flexible. Because the marker band 108 is not flexible, the catheter 100 may have problems when tracking due to the use of a rigid marker band 108 at the distal end of the catheter. The rigid marker band 108 adversely affects catheter navigation because the metal hypotube marker band 108 is ridged and cannot bend. In addition, conventional marker bands must be separately attached to the catheter shaft. These conventional marker bands are known to detach from the catheter body during clinical use, particularly if the gap between the marker band and the rest of the catheter body is too large.

[0040] Aspects of the disclosure are also provided by the following numbered clauses:

[0041] Clause 1: A catheter 10 for navigating within a body cavity, the catheter comprising:

[0042] a liner 12 having a proximal end 14, a distal end 16, an outer surface 18, an inner lumen 20 extending from the proximal end 14 to the distal end 16, and a longitudinal axis A;

[0043] a braid 22 disposed on the outer surface 18 of the liner 12 and extending from the proximal end 14 to the distal end 16 of the liner 12, the braid 22 comprising a plurality of wires 24, 26, wherein a first portion 24 of the wires is made of tungsten and a second portion 26 of the wires is made of a different material; and

[0044] A sheath 28 is disposed around the braid 22 and extends from the proximal end 14 to the distal end 16 .

[0045] Clause 2. The catheter of Clause 1, wherein the first portion 24 of the wire is approximately half of the wire, and the second portion 26 of the wire is approximately half of the wire.

[0046] Clause 3. The catheter of Clause 1 or 2, wherein the first portion 24 of the wire is half of the wire and the second portion 26 of the wire is half of the wire.

[0047] Clause 4. The catheter of any of Clauses 1 to 3, wherein the first portion of wires 24 comprises eight wires, and the second portion of wires 26 comprises eight wires.

[0048] Clause 5. The catheter of any one of Clauses 1 to 4, wherein the second portion 26 of the wire is made of stainless steel.

[0049] Clause 6. The catheter according to any one of clauses 1 to 5, wherein the liner 12 is made of PTFE.

[0050] Clause 7. The catheter of any one of Clauses 1 to 6, wherein the sheath 28 is made of a polymer material.

[0051] Clause 8. The catheter of any one of Clauses 1 to 7, wherein the sheath 28 is comprised of a plurality of segments.

[0052] Clause 9. The catheter of any one of Clauses 1 to 8, wherein the sheath 28 is composed of eight segments.

[0053] Clause 10. The catheter of any one of Clauses 1 to 9, wherein the braid 22 has a plurality of pic rates along the longitudinal axis.

[0054] Clause 11. A catheter according to any one of clauses 1 to 10, wherein the braid has at least four axial segments extending from the distal end 16 toward the proximal end 14, the at least five axial segments including a first distal-most segment 32, a second distal segment 34 adjacent to the first distal-most segment, a third distal segment 36 adjacent to the second distal segment, and a fourth proximal segment 38 adjacent to the third distal segment, the second distal segment being located between the first distal segment and the third distal segment, and the third distal segment being located between the second distal segment and the fourth proximal segment.

[0055] Clause 12. The catheter of any one of Clauses 1 to 11, wherein the braid first distal section 32 has a braid rate of approximately 330 stitches per inch ("ppi").

[0056] Clause 13. The catheter of any of Clauses 1 to 12, wherein the braided first distal section 32 has an axial length of about 0.010 inches to about 0.039 inches.

[0057] Clause 14. The catheter of any one of Clauses 1 to 13, wherein the braid second distal section 34 has a braid rate of approximately 105 ppi.

[0058] Clause 15. The catheter of any one of Clauses 1 to 14, wherein the braided second distal section 34 has an axial length of approximately 7.87 inches.

[0059] Clause 16. The catheter of any one of Clauses 1 to 15, wherein the braided third distal section 36 has a variable braid ratio of about 105 ppi to about 195 ppi.

[0060] Clause 17. The catheter of any one of clauses 1 to 16, wherein the braided third distal section 36 has a variable braid ratio of about 105 ppi adjacent the proximal end of the third distal section to about 195 ppi adjacent the distal end of the third distal section.

[0061] Clause 18. The catheter of any of Clauses 1 to 17, wherein the braid third distal section 36 has a variable braid ratio that continuously transitions from the proximal end of the third distal section to the distal end of the third distal section.

[0062] Clause 19. The catheter of any one of Clauses 1 to 16, wherein the braided third distal section 36 has an axial length of approximately 7.87 inches.

[0063] Clause 20. The catheter of any one of Clauses 1 to 19, wherein the braid fourth proximal section 38 has a braid rate of approximately 195 ppi.

[0064] Clause 21. The catheter of any one of Clauses 1 to 20, wherein the braided fourth proximal section 38 has an axial length of approximately 44.0 inches.

[0065] Clause 22. A catheter 10 for navigating within a body cavity, the catheter comprising:

[0066] a liner 12 having a proximal end 14, a distal end 16, an outer surface 18, an inner lumen 20 extending from the proximal end 14 to the distal end 16, and a longitudinal axis A;

[0067] a braid 22 disposed on the outer surface 18 of the liner 12 and extending from the proximal end 14 to the distal end 16 of the liner 12, the braid 22 having at least four axial segments extending from the distal end 16 toward the proximal end 14, the at least four axial segments including a first distal-most segment 32, a second distal segment 34 adjacent to the first distal-most segment 32, a third distal segment 36 adjacent to the second distal segment 34, and a distal-most segment 32 extending from the distal end 16 to the distal end 16. a fourth proximal section 38 adjacent to the third distal section 36, the second distal section 34 being located between the first distal section 32 and the third distal section 36, the third distal section 36 being located between the second distal section 34 and the fourth proximal section 38, the fourth proximal section 38 being adjacent to and proximal to the third distal section 36, the braid first distal section 32 having a braid rate of approximately 330 stitches per inch ("ppi"); and

[0068] A sheath 28 is disposed around the braid 22 and extends from the proximal end 14 to the distal end 16 .

[0069] Clause 23. The catheter of Clause 22, wherein the braided first distal section 32 has an axial length of about 0.010 inches to about 0.039 inches.

[0070] Clause 24. The catheter of any of Clauses 22 to 23, wherein the braid second distal section 34 has a braid rate of approximately 105 ppi.

[0071] Clause 25. The catheter of any of Clauses 22 to 24, wherein the braided second distal section 34 has an axial length of approximately 7.87 inches.

[0072] Clause 26. The catheter of any of Clauses 22 to 25, wherein the braided third distal section 36 has a variable braid ratio of about 105 ppi to about 195 ppi.

[0073] Clause 27. The catheter of any one of clauses 22 to 26, wherein the braided third distal section 36 has a variable braid ratio of approximately 105 ppi adjacent the proximal end of the third distal section 36 to approximately 195 ppi adjacent the distal end of the third distal section 36.

[0074] Clause 28. The catheter of any one of Clauses 22 to 27, wherein the braided third distal section 36 has a variable braid ratio that continuously transitions from the proximal end of the third distal section 36 to the distal end of the third distal section 36 .

[0075] Clause 29. The catheter of any of Clauses 22 to 28, wherein the braided third distal section 36 has an axial length of approximately 7.87 inches.

[0076] Clause 30. The catheter of any one of Clauses 22 to 29, wherein the braid fourth proximal section 38 has a braid rate of approximately 195 ppi.

[0077] Clause 31. The catheter of any one of Clauses 22 to 30, wherein the braided fourth proximal section 38 has an axial length of approximately 44.0 inches.

[0078] Clause 32. The catheter of any of Clauses 22 to 31, wherein the braid 22 comprises a plurality of wires, wherein a first portion 24 of the wires is made of tungsten and a second portion 26 of the wires is made of a different material.

[0079] Clause 33. The catheter of any of Clauses 22 to 32, wherein the first portion of wires 24 comprises eight wires, and the second portion of wires 26 comprises eight wires.

[0080] Clause 34. The catheter of any one of Clauses 22 to 33, wherein the second portion 26 of the wire is made of stainless steel.

[0081] The descriptions contained herein are examples of embodiments of the present disclosure and are not intended to limit the scope of the present disclosure in any way. As described herein, the present disclosure contemplates many variations and modifications of the catheter. Modifications and variations that would be apparent to one skilled in the relevant art in light of the teachings of this disclosure are intended to fall within the scope of the appended claims.

Claims

1. A catheter for navigating within a body cavity, the catheter comprising: a liner having a proximal end, a distal end, an outer surface, a lumen extending from the proximal end to the distal end, and a longitudinal axis; a braid disposed on the outer surface of the liner and extending from the proximal end to the distal end of the liner, the braid comprising a plurality of wires, wherein a first portion of the wires is made of tungsten and a second portion of the wires is made of a different material; and A sheath is disposed about the braid and extends from the proximal end to the distal end.

2. The catheter according to claim 1, wherein The first portion of the wire is approximately half of the wire, and the second portion of the wire is approximately half of the wire.

3. The catheter according to claim 2, wherein The first portion of the wire is half of the wire, and the second portion of the wire is half of the wire.

4. The catheter according to claim 3, wherein The first portion of wires includes eight wires, and the second portion of wires includes eight wires.

5. The catheter according to claim 1, wherein The braid has a plurality of braid ratios along the longitudinal axis. The catheter according to claim 5 , wherein: The braid has at least four axial segments extending from the distal end toward the proximal end, the at least five axial segments including a first distal-most segment, a second distal segment adjacent to the first distal-most segment, a third distal segment adjacent to the second distal segment, and a fourth proximal segment adjacent to the third distal segment, the second distal segment being located between the first and third distal segments, and the third distal segment being located between the second and fourth proximal segments.

7. The catheter according to claim 6, wherein The braid first distal section has a braid rate of approximately 330 stitches per inch ("ppi").

8. The catheter according to claim 7, wherein The braid first distal section has an axial length of about 0.010 inches to about 0.039 inches.

9. The catheter according to claim 8, wherein The braid second distal section has a braid rate of approximately 105 ppi.

10. The catheter according to claim 9, wherein The braid second distal section has an axial length of approximately 7.87 inches.

11. The catheter according to claim 10, wherein The braid third distal section has a variable braid ratio of about 105 ppi to about 195 ppi.

12. The catheter according to claim 11, wherein The braid third distal section has a variable braid ratio of approximately 105 ppi adjacent a proximal end of the third distal section to approximately 195 ppi adjacent a distal end of the third distal section.

13. The catheter according to claim 12, wherein The braid third distal section has a variable braid rate that continuously transitions from the proximal end of the third distal section to the distal end of the third distal section.

14. The catheter according to claim 13, wherein The braid third distal section has an axial length of approximately 7.87 inches.

15. The catheter according to claim 14, wherein The braid fourth proximal section has a braid rate of approximately 195 ppi.

16. The catheter according to claim 15, wherein The braid fourth proximal section has an axial length of approximately 44.0 inches.

17. A catheter for navigating within a body cavity, the catheter comprising: a liner having a proximal end, a distal end, an outer surface, a lumen extending from the proximal end to the distal end, and a longitudinal axis, a braid disposed on the outer surface of the liner and extending from the proximal end to the distal end of the liner, the braid having at least four axial segments extending from the distal end toward the proximal end, the at least four axial segments including a first distal-most segment, a second distal segment adjacent to the first distal-most segment, a third distal segment adjacent to the second distal segment, and a fourth proximal segment adjacent to the third distal segment, the second distal segment being between the first and third distal segments, the third distal segment being between the second and fourth proximal segments, the fourth proximal segment being adjacent to and proximal to the third distal segment, the first distal segment of the braid having a braid rate of approximately 330 stitches per inch (ppi); and A sheath is disposed about the braid and extends from the proximal end to the distal end.

18. The catheter according to claim 17, wherein The braid first distal section has an axial length of about 0.010 inches to about 0.039 inches.

19. The catheter according to claim 18, wherein The braid second distal section has a braid rate of approximately 105 ppi.

20. The catheter of claim 19, wherein The braid third distal section has a variable braid ratio of about 105 ppi to about 195 ppi.

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