Guidewires for medical devices

Abstract

The guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment being coupled to the blunt tip, and the shaft body segment including a flat portion having one or more openings extending through the thickness of the flat portion.

Description

[Technical field]

[0001] The field of the present application relates to medical devices, and more particularly to guidewires for medical devices and medical devices having such guidewires. [Background technology]

[0002] Guidewires are used in the medical field to access passageways within a patient's body. In some cases, it may be desirable for a guidewire to have good torque transmission, allowing a torque motion applied at a proximal end of the guidewire about the guidewire's longitudinal axis to cause a corresponding twisting motion at the guidewire's distal end.

[0003] It may also be desirable for the distal segment of the guidewire to maintain a particular curved shape during use, which allows the distal segment of the guidewire to access a particular passageway having a particular shape within the patient's body. If the distal segment of the guidewire cannot maintain its curved shape during use, it may not be able to access the target passageway.

[0004] Additionally, it may be desirable for the guidewire to have a soft distal segment, which prevents the guidewire from causing injury to the patient and also allows the guidewire to bend or curve elastically as it is advanced within the patient's body through passageways of various shapes.

[0005] However, it is difficult for a guidewire to achieve all of the above desirable features. Although a guidewire may have a soft distal segment, such a guidewire may have poor shape retention and poor torque transmission at the distal segment. On the other hand, some guidewires have good shape retention and good torque transmission at the distal segment. However, such guidewires may have a stiff distal segment. It is difficult to simultaneously achieve the above desirable features because a soft distal segment of a guidewire usually cannot achieve good torque transmission due to the softness of the material used to make the distal segment. Also, the material used to make a soft distal guidewire segment may not allow the distal guidewire segment to maintain its shape during use. Summary of the Invention

[0006] The guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment being coupled to the blunt tip, and the shaft body segment including a flat portion having one or more openings extending through a thickness of the flat portion.

[0007] Optionally, the one or more openings include only one elongated slot extending through the thickness of the planar portion.

[0008] Optionally, the flat portion has a long side parallel to the longitudinal axis of the guidewire, and the slot has a long side parallel to the long side of the flat portion.

[0009] Optionally, the one or more openings include a series of openings disposed along a longitudinal axis of the planar portion.

[0010] Optionally, each of the series of openings is a rectangular slot extending through the thickness of the planar portion.

[0011] Optionally, each of the series of openings is a circular slot extending through the thickness of the planar portion.

[0012] Optionally, the one or more openings include a row of openings arranged in a staggered arrangement.

[0013] Optionally, the guidewire further includes a radiopaque marker extending through one of the one or more openings.

[0014] Optionally, the radiopaque marker comprises a first portion abutting the first side of the flat portion, a second portion within one of the one or more openings, and a third portion abutting the second side of the flat portion, the second side being opposite the first side of the flat portion.

[0015] Optionally, a first portion of the radiopaque marker has a first cross-sectional dimension, a second portion of the radiopaque marker has a second cross-sectional dimension, and a third portion of the radiopaque marker has a third cross-sectional dimension, the first cross-sectional dimension being greater than the second cross-sectional dimension, and the third cross-sectional dimension being greater than the second cross-sectional dimension.

[0016] Optionally, the flat portion comprises a pressed core wire.

[0017] Optionally, the guidewire further includes a coil disposed between the flat portion and the sleeve.

[0018] Optionally, the coil is made from a radiopaque material.

[0019] Optionally, the coil is made from platinum tungsten.

[0020] Optionally, the sleeve is made from Nitinol.

[0021] Optionally, the sleeve includes a plurality of slots.

[0022] Optionally, the body of the shaft includes a tapered portion proximal to the flat portion.

[0023] Optionally, the body of the shaft comprises a cylindrical portion proximal to the tapered portion.

[0024] Optionally, the flat portion is configured to be bendable to form a curved shape and to retain the curved shape after the flat portion is bent.

[0025] Optionally, the segment also includes an additional flat portion distal to the flat portion.

[0026] Optionally, the segment also comprises a connecting portion connecting the planar portion and the further planar portion, the connecting portion, the planar portion and the further planar portion having an integral configuration.

[0027] The medical device includes a catheter and a guidewire, the catheter including a lumen for receiving the guidewire.

[0028] The guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment coupled to the blunt tip, the shaft body segment including a flat portion having a first major surface and a second major surface opposite the first major surface, the flat portion including one or more radiopaque markers secured to the first major surface.

[0029] Optionally, the one or more radiopaque markers include a first planar marker having a width the same as a width of the planar portion.

[0030] Optionally, the guidewire further includes a second planar marker fixed on a second major surface of the planar portion.

[0031] Optionally, the one or more radiopaque markers include a first plurality of radiopaque markers spaced apart from one another.

[0032] Optionally, the first plurality of radiopaque markers are aligned in a row along the longitudinal axis of the planar portion.

[0033] Optionally, the guidewire further includes a second plurality of radiopaque markers spaced apart from one another and secured on a second major surface of the planar portion.

[0034] Optionally, the flat portion also includes one or more radiopaque markers fixed on the second major surface.

[0035] The guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment coupled to the blunt tip, the shaft body segment including a flat portion having an outer surface, the flat portion including a plurality of grooves on the outer surface.

[0036] The guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the body of the shaft including at least a segment surrounded by the sleeve, the segment coupled to the blunt tip, the guidewire further including a radiopaque coil surrounding at least a portion of the segment, the portion of the segment having opposing faces with a recess along each of the faces to allow the radiopaque coil to be screwed onto the portion of the segment.

[0037] Optionally, a portion of the segment includes a flat portion.

[0038] Optionally, the segment includes a flat portion, and the portion of the segment is proximal to the flat portion.

[0039] Other and further aspects and features will become apparent from a reading of the following detailed description. [Brief description of the drawings]

[0040] The drawings illustrate the design and utility of the embodiments, in which similar elements are referenced with common numerals. The drawings are not necessarily drawn to scale. To better understand how the above and other advantages and objects are obtained, a more particular description of the embodiments illustrated in the accompanying drawings will be rendered. The drawings depict only exemplary embodiments and therefore should not be considered as limiting the scope of the claims.

[0041] [Figure 1] FIG 1A shows a guidewire. FIG 1B shows the guidewire of FIG 1A further having a sleeve and a tip. FIG 1C shows the guidewire of FIG 1B further having a coil. FIG 1D shows the guidewire of FIG 1B further having a coil spaced apart from the wall of the sleeve. FIG 1E shows the guidewire of FIG 1A further having a sleeve and a tip. FIG 1F shows a member for manufacturing the guidewire. [Diagram 2] FIG 2A shows a guidewire. FIG 2B shows the guidewire of FIG 2A further having a sleeve and a tip. FIG 2C shows the guidewire of FIG 2B further having a malleable structure. FIG 2D shows the guidewire of FIG 2B further having a coil. FIG 2E shows the guidewire of FIG 2D further having a malleable structure and a coil. FIG 2F shows a member for manufacturing the guidewire. [Diagram 3] Figure 3A shows a guidewire, Figure 3B shows the guidewire of Figure 3A further having a coil, Figure 3C shows the guidewire of Figure 3B further having a malleable structure and a coil, and Figure 3D shows the guidewire of Figure 3A further having a malleable structure. [Figure 4] FIG. 4 shows a guidewire. [Diagram 5] FIG. 5 shows an alternative guidewire. [Figure 6] FIG. 6 shows an alternative guidewire. [Figure 7] FIG. 7 shows an alternative guidewire. [Figure 8] FIG. 8 shows an alternative guidewire. [Figure 9] FIG. 9 shows an alternative guidewire. [Figure 10] 10A to 10H show a method for manufacturing a guidewire. [Figure 11] FIG. 11 shows a flattened portion of a segment of a guidewire. [Figure 12] FIG. 12 shows another flattened portion of a segment of a guidewire. [Figure 13] FIG. 13 shows an alternative guidewire. [Figure 14] FIG. 14 shows an alternative guidewire. [Figure 15] FIG. 15 illustrates a technique for securing radiopaque markers to a portion of a guidewire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Various embodiments will be described below with reference to the drawings. It should be noted that the drawings are not drawn to scale, and elements of similar structure or function are represented by the same reference numerals throughout the drawings. It should also be noted that the drawings are intended only to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. Furthermore, the illustrated embodiments do not necessarily have all the aspects or advantages shown. An aspect or advantage described in connection with a particular embodiment is not necessarily limited to that embodiment, and may be implemented in any other embodiment, even if not so illustrated or not so explicitly described.

[0043] 1A illustrates a guidewire 100 according to some embodiments. The guidewire 100 includes a shaft 110 having a proximal end 112, a distal end 114, and a body 116 extending from the proximal end 112 to the distal end 114. The body 116 of the shaft 110 includes a distal segment 120 having a number of different cross sections along the length of the distal segment 120. At least an outer portion 130 of the body 116 proximal to the distal segment 120 is made of a material having a shear modulus of at least 13,000 ksi. By way of non-limiting example, the material of the outer body portion 130 is a molybdenum-rhenium alloy or a tungsten-rhenium alloy.

[0044] In the illustrated embodiment, the shaft 110 includes a first layer 140, a second layer 142, and a third layer 144. The third layer 144 is outside the second layer 142, which is outside the first layer 140. As illustrated, the third layer 144 includes the outer portion 130 of the body 116 proximal to the distal segment 120. In some embodiments, the third layer 144 of the shaft 110 can be made from a molybdenum rhenium alloy or a tungsten rhenium alloy. Also, in some embodiments, the first layer 140 can be made from a molybdenum rhenium alloy, a tungsten rhenium alloy, stainless steel, Nitinol, a neo-nickel alloy (e.g., MP35N alloy), or a cobalt chrome alloy. The second layer 142 can be made from Nitinol, or from other materials.

[0045] In the illustrated embodiment, portion 150 of first layer 140 is distal to distal end 152 of second layer 142, and portion 154 of second layer 142 is distal to distal end 156 of third layer 144, thereby enabling portion 150 of first layer 140 and portion 154 of second layer 142 to form at least a portion of distal segment 120 of body 116 of shaft 110. Such a configuration is advantageous because it provides distal segment 120 with a smaller cross-sectional dimension than the cross-sectional dimension of the remainder of body 116 (the portion proximal to distal segment 120). As a result, distal segment 120 is softer and can flex or bend more easily than the remainder of body 116.

[0046] In some embodiments, the portion 150 of the first layer 140 may be compressed to form an elongated cross-sectional shape of the portion 150 of the first layer 140. For example, in one embodiment, the first layer 140 may have a circular cross-sectional shape, and the portion 150 of the first layer 140 may be compressed into either a planar configuration having an elongated cross-sectional shape, or into another non-circular cross-section. This feature is advantageous because it biases the portion 150 of the first layer 140 in a bending direction. Compression of the portion 150 of the first layer 140 may be achieved in some embodiments by pressing the portion 150 of the first layer 140.

[0047] In one specific embodiment, both the first layer 140 and the third layer 144 are made of molybdenum-rhenium alloy, and the second layer 142 is made of nitinol sandwiched between the two molybdenum-rhenium alloy layers 140, 144. In another specific embodiment, the first layer 140 is made of stainless steel or a cobalt-chromium alloy (e.g., MP35N alloy), the second layer 142 is made of nitinol, and the third layer is made of molybdenum-rhenium alloy. In either embodiment, the nitinol layer 142 provides kink resistance and a softer distal segment 120. The first layer 140 is moldable during use, providing desirable shape retention. Additionally, the outer molybdenum-rhenium alloy layer 144 provides desirable torque transmission due to its relatively high shear modulus. Additionally, the axial stiffness of the outer molybdenum-rhenium alloy layer 144 also provides desirable pushability for the guidewire 100.

[0048] As shown in FIG. 1B, in some embodiments, the guidewire 100 can also include a sleeve 180 disposed around at least a portion of the distal segment 120 (e.g., distal end 114) of the shaft 110. As shown, the sleeve 180 has a blunt tip 182. The distal end 114 of the shaft 110 is coupled to the blunt tip 182. The sleeve 180 can be any tubular member and can be made of any material, such as a metal, a polymer, or the like. In some embodiments, the sleeve 180 can be made of Nitinol. The sleeve 180 can have multiple slots and / or openings to increase the flexibility of the sleeve 180. As non-limiting examples, the sleeve 180 can be realized using a slotted hypotube, a coiled sleeve, a tungsten-loaded polymer sleeve, or combinations thereof.

[0049] 1C, in some embodiments, the guidewire 100 can also include a marker coil 190 disposed within the sleeve 180. As shown, one end of the marker coil 190 is secured to the tip 182, and the body of the marker coil 190 is secured to or abuts the wall of the sleeve 180. In other embodiments, the coil 190 is coupled only to the tip 182, and not to the wall of the sleeve 180 (FIG. 1D). In other embodiments, the proximal end of the marker coil 190 is secured to the second layer 154 (e.g., the distal end 152 of the second layer 154) by adhesive, welding, a mechanical connector, fusion, or the like. In further embodiments, at least a portion of the sleeve 180 is formed by the marker coil 190 (FIG. 1E). As shown, the marker coil 190 has a cross-sectional dimension that corresponds to (e.g., the same as) the cross-sectional dimension of the sleeve 180. In some cases, the entire length of the sleeve 180 can be made from a coil, such as a marker coil.

[0050] In the illustrated embodiment of FIGS. 1A-1E, the distal portion 150 of the segment 120 is malleable. Thus, the distal portion 150 of the segment 120 can be bent to form a curved shape. The distal portion 150 is made of a material that allows the distal portion 150 of the segment 120 to retain the curved shape after being bent. In other embodiments, the distal portion 150 (or the first layer 140 that includes the distal portion 150) can be made of a material that does not have sufficient shape retention capabilities. In such cases, the guidewire 100 can further include a malleable structure attached to the blunt tip 182. The malleable structure can be inside the sleeve 180. During use, the malleable structure can be bent to form a curved shape and is configured to retain the curved shape after the malleable structure is bent. In some embodiments, the malleable structure can be made of a molybdenum-rhenium alloy or a tungsten-rhenium alloy.

[0051] Guidewire 100 is advantageous because it provides desirable torque transmission, desirable pushability, and desirable shape retention while achieving desirable softness in distal segment 120. In particular, outermost layer 144 is made of a material having a sufficiently high shear modulus (e.g., at least 13,000 ksi) to provide desirable torque transmission. Distal segment 120 also has desirable bending stiffness, and distal portion 150 also has desirable bending stiffness and shape retention. Thus, guidewire 100 has an optimal combination of a soft distal segment, shape retention, and torque retention.

[0052] FIG. 1F illustrates a member 194 for manufacturing guidewire 100. Member 194 includes first layer 140, second layer 142, and third layer 144. In some embodiments, a portion of third layer 144 can be removed to expose portion 154 of second layer 142. Also, a portion of second layer 142 can be removed to expose portion 150 of first layer 140. This action results in shaft 110 having multiple different cross-sectional shapes along its length, as shown in FIGS. 1A-1E. In some embodiments, removal of portion of third layer 144 and portion of second layer 142 can be accomplished by grinding, cutting, polishing, or any combination thereof.

[0053] In the embodiment described above, shaft 110 of guidewire 100 has three layers 140, 142, 144. In other embodiments, shaft 110 of guidewire 100 can have more than three layers or less than three layers (e.g., two layers).

[0054] FIG. 2A illustrates a guidewire 100 according to some embodiments. Unlike the guidewire of FIG. 1A, the guidewire 100 of FIG. 2A has only two layers 140, 142. Referring to FIG. 2A, the guidewire 100 includes a shaft 110 having a proximal end 112, a distal end 114, and a body 116 extending from the proximal end 112 to the distal end 114. The body 116 of the shaft 110 includes a distal segment 120 having a plurality of different cross sections along the length of the distal segment 120. At least an outer portion 130 of the body 116 proximal to the distal segment 120 is made of a material having a shear modulus of at least 13,000 ksi. As a non-limiting example, the material of the outer portion 130 of the body is a molybdenum-rhenium alloy or a tungsten-rhenium alloy.

[0055] In the illustrated embodiment, the shaft 110 includes a first layer 140 and a second layer 142. The second layer 142 is exterior to the first layer 140. As illustrated, the second layer 142 includes the exterior portion 130 of the body 116 proximal to the distal segment 120. In some embodiments, the second layer 142 of the shaft 110 can be made from a molybdenum-rhenium alloy or a tungsten-rhenium alloy. Also, in some embodiments, the first layer 140 can be made from a material having a shear modulus less than the shear modulus of the second layer 142. As non-limiting examples, the first layer 140 can be made from stainless steel, nitinol, cobalt-chromium alloy (e.g., MP35N alloy), and the like.

[0056] In the illustrated embodiment, the segment 120 of the shaft 110 is made from the first layer 140. The segment 120 is distal to the distal end 152 of the second layer 142. The segment 120 of the first layer 140 has a first portion 210, a second portion 214, and a third portion 216. The third portion 216 has a cross-sectional dimension smaller than that of the first portion 210, and the smaller cross-sectional dimension of the third portion 216 transitions to the larger cross-sectional dimension of the first portion 210 through the second (middle) portion 214. Such a configuration is advantageous because it provides a gradually softer section from proximal to distal. As a result, the distal segment 120 is softer compared to the remainder of the body 116, with the distal portion 216 providing the softest section and being able to flex or bend more easily. In other embodiments, the segment 120 can include more or fewer portions than those described above.

[0057] In some embodiments, the third portion 216 of the segment 120 may be compressed to form an elongated cross-sectional shape for the portion 216 of the segment 120. For example, in one embodiment, the first layer 140 may have a circular cross-sectional shape, and the portion 216 of the first layer 140 may be compressed either into a planar configuration having an elongated cross-sectional shape, or into another non-circular shape. This feature is advantageous because it biases the portion 216 of the first layer 140 in a bending direction. Compression of the portion 216 of the first layer 140 may be achieved in some embodiments by pressing the portion 216 of the first layer 140.

[0058] In one specific embodiment, the second layer 142 is made from a molybdenum-rhenium alloy and the first layer 140 is made from nitinol. The inner nitinol layer 140 provides the guidewire 100 with kink resistance and a soft distal end, while the outer layer 142 provides the desired pushability and torqueability. In another specific embodiment, the second layer 142 is made from a molybdenum-rhenium alloy and the first layer 140 is made from a stainless steel or cobalt-chromium alloy (e.g., MP35N alloy). The first layer 140 provides kink resistance and a softer distal segment 120. The first layer 140 may be moldable during use to provide the desired shape retention capabilities (e.g., with or without the aid of a malleable structure). The outer molybdenum-rhenium alloy layer 142 also provides the desired torqueability due to its relatively high shear modulus. Additionally, the axial stiffness of outer molybdenum-rhenium alloy layer 142 also provides guidewire 100 with desirable pushability.

[0059] As shown in FIG. 2B, in some embodiments, the guidewire 100 can also include a sleeve 180 disposed around at least a portion of the distal segment 120 of the shaft 110 (e.g., the distal end 114). As shown, the sleeve 180 has a blunt tip 182. The distal end 114 of the shaft 110 is coupled to the blunt tip 182. The sleeve 180 can be any tubular member and can be made from any material, such as a metal, a polymer, or the like. In some embodiments, the sleeve 180 can be made from Nitinol. The sleeve 180 can have multiple slots and / or openings to increase the flexibility of the sleeve 180. As non-limiting examples, the sleeve 180 can be realized using a slotted hypotube, a coiled sleeve, a tungsten-loaded polymer sleeve, or combinations thereof.

[0060] In the exemplary embodiment of Figures 2A and 2B, the distal portion 216 of the segment 120 is malleable. Thus, the distal portion 216 of the segment 120 can be bent to form a curved shape. The distal portion 216 is made of a material that allows the distal portion 216 of the segment 120 to retain the curved shape after it is bent. In other embodiments, as shown in Figure 2C, the distal portion 216 (or the first layer 140 including the distal portion 216) can be made of a material that does not have sufficient shape retention capabilities. In such cases, the guidewire 100 can further include a malleable structure 230 attached to the blunt tip 182. The malleable structure 230 can be inside the sleeve 180. The malleable structure 230 is configured to be bent to form a curved shape during use and to retain the curved shape after the malleable structure 230 is bent. In some embodiments, the malleable structure 230 may be made from a molybdenum-rhenium alloy or a tungsten-rhenium alloy to provide the guidewire 100 with desirable shape-retaining capabilities.

[0061] 2D, in some embodiments, the guidewire 100 can also include a marker coil 190 disposed within the sleeve 180. As shown, one end of the marker coil 190 is secured to the tip 182, and the body of the marker coil 190 is secured to or abuts the wall of the sleeve 180. In other embodiments, the coil 190 is coupled only to the tip 182 and not to the wall of the sleeve 180. In other embodiments, the proximal end of the marker coil 190 can be secured to the distal segment 120 (e.g., at any location proximal to portion 216, such as portion 214, portion 210, etc.). The securing can be accomplished using adhesives, welding, mechanical connectors, fusion, etc. In further embodiments, at least a portion of the sleeve 180 can be formed by the marker coil 190. In such cases, the marker coil 190 has a cross-sectional dimension that corresponds to (e.g., the same as) the cross-sectional dimension of the sleeve 180. In some cases, the entire length of the sleeve 180 can be made from a coil, such as a marker coil.

[0062] In some embodiments, guidewire 100 can include both a malleable structure 230 and a marker coil 190 (FIG. 2E).

[0063] FIG. 2F illustrates a member 290 for manufacturing a guidewire. The member 290 includes a first layer 140 and a second layer 142. In some embodiments, a portion of the second layer 142 can be removed to expose the first layer 140. It is also possible to remove a portion of the exposed first layer 140, and more material can be removed distally than proximally. This action results in the shaft 110 having multiple different cross-sectional shapes along its length, as shown in FIGS. 2A-2E. In some embodiments, the removal of the portion of the second layer 142 and the portion of the exposed first layer 140 can be accomplished by grinding, cutting, polishing, or any combination thereof.

[0064] In further embodiments, the shaft 110 of the guidewire 100 can have a single layer. FIG. 3A illustrates a guidewire 100 according to some embodiments. The guidewire 100 of FIG. 3A, unlike the guidewires of FIGS. 1A and 1B, has only one layer in each of the distal and proximal segments of the shaft 110. Referring to FIG. 3A, the guidewire 100 includes a shaft 110 having a proximal end 112, a distal end 114, and a body 116 extending from the proximal end 112 to the distal end 114. The body 116 of the shaft 110 includes a distal segment 120 having a plurality of different cross sections along the length of the distal segment 120. At least an outer portion 130 of the body 106 proximal to the distal segment 120 is made of a material having a shear modulus of at least 13,000 ksi. As a non-limiting example, the material of the outer portion 130 of the body is a molybdenum-rhenium alloy or a tungsten-rhenium alloy.

[0065] In the illustrated embodiment, the shaft 110 includes a proximal segment 300 made of a first material and a distal segment 120 made of a second material different from the first material. In some embodiments, the proximal segment 300 can be made of a molybdenum-rhenium alloy or a tungsten-rhenium alloy. Also, in some embodiments, the distal segment 120 can be made of Nitinol, stainless steel, or a cobalt-chromium alloy (e.g., MP35N alloy).

[0066] As shown, the distal segment 120 has a single layer and includes a first portion 301, a second portion 302, a third portion 304, a fourth portion 306, and a fifth portion 308. The fifth portion 308 has a smaller cross-sectional dimension compared to the cross-sectional dimension of the third portion 304, which transitions to the larger cross-sectional dimension of the third portion 304 through the fourth (middle) portion 306. Similarly, the third portion 304 has a smaller cross-sectional dimension compared to the cross-sectional dimension of the first portion 301, which transitions to the larger cross-sectional dimension of the first portion 301 through the second (middle) portion 302. Such a configuration is advantageous because it provides a gradually softer section from proximal to distal. As a result, the distal segment 120 is softer than the remainder of the body 116, with the distal portion 308 providing the softest section and allowing it to flex or bend more easily. In other embodiments, the distal segment 120 may include more or fewer portions than those described above.

[0067] The proximal segment 300 also has a single layer. The proximal segment 300 can be attached to the distal segment 120 via adhesive, welding, a mechanical connector, or fusion.

[0068] As shown, the inner portion 330 of the body 116 proximal to the segment 120 and the outer portion 300 of the body 116 proximal to the segment 120 are made from the same material (as shown by the cross-hatched cross section). In one embodiment, the outer portion 300 and the inner portion 330 of the body 116 are made from the same source material (e.g., molybdenum rhenium alloy, tungsten rhenium alloy, etc.) and thus have a unitary construction.

[0069] In some implementations, portion 308 of segment 120 may be compressed to form an elongated cross-sectional shape for portion 308. For example, in one implementation, portion 308 may have a circular cross-sectional shape, and portion 308 of segment 120 may be compressed into either a planar configuration having an elongated cross-sectional shape, or into another non-circular cross-sectional shape. This feature is advantageous because it provides a bias for portion 308 in a bending direction. Compression of portion 308 may be achieved in some embodiments by pressing portion 308.

[0070] In the illustrated embodiment, the guidewire 100 also includes a sleeve 180 disposed about the distal end 114 of the shaft 110. As illustrated, the sleeve 180 has a blunt tip 182. The distal end 114 of the shaft 110 is coupled to the blunt tip 182. The sleeve 180 may be any tubular member and may be made from any material, such as a metal, a polymer, or the like. In some embodiments, the sleeve 180 may be made from Nitinol. The sleeve 180 may have multiple slots and / or openings to increase the flexibility of the sleeve 180. By way of non-limiting example, the sleeve 180 may be realized using a slotted hypotube, a coiled sleeve, a tungsten-loaded polymer sleeve, or a combination thereof.

[0071] In one specific embodiment, the proximal segment 300 is made of a molybdenum-rhenium alloy and the distal segment 120 is made of nitinol. In another specific embodiment, the proximal segment 300 is made of a molybdenum-rhenium alloy and the distal segment 120 is made of stainless steel or a cobalt-chromium alloy (e.g., MP35N alloy). In either embodiment, the distal segment 120 provides the guidewire 100 with a kink-resistant and soft distal end, and the proximal segment 300 provides the desired pushability and the desired torqueability. The distal segment 120 may be moldable during use (e.g., with or without the aid of the malleable structure 230) to provide the desired shape retention capabilities. The molybdenum-rhenium alloy proximal segment 300 also provides the desired torqueability due to its relatively high shear modulus. Additionally, the axial stiffness of the molybdenum-rhenium alloy segment 300 also provides the guidewire 100 with the desired pushability.

[0072] 3B, in some embodiments, the guidewire 100 can also include a marker coil 190 disposed within the sleeve 180. As shown, one end of the marker coil 190 is fixed to the tip 182. In other embodiments, the proximal end of the marker coil 190 is fixed to the distal segment 120 (e.g., at any location proximal to portion 308, such as portion 306, portion 304, or portion 302). In other embodiments, the coil 190 is also coupled to the wall of the sleeve 180. In further embodiments, at least a portion of the sleeve 180 can be formed by the marker coil 190. In such cases, the marker coil 190 has cross-sectional dimensions that correspond to (e.g., the same as) the cross-sectional dimensions of the sleeve 180. In some cases, the entire length of the sleeve 180 can be made from a coil, such as a marker coil.

[0073] In the exemplary embodiment of FIGS. 3A and 3B, the distal portion 308 of the segment 120 is malleable. Thus, the distal portion 308 of the segment 120 can be bent to form a curved shape. The distal portion 308 is made from a material that allows the distal portion 308 of the segment 120 to retain the curved shape after being bent. In other embodiments, the distal portion 150 can be made from a material that does not have sufficient shape retention capabilities. In such cases, the guidewire 100 can further include a malleable structure 230 attached to the blunt tip 182 (FIG. 3C). The malleable structure 230 can be inside the sleeve 180. The malleable structure 230 can be bent to form a curved shape during use and is configured to retain the curved shape after the malleable structure 230 is bent. In some embodiments, the malleable structure 230 can be made from a molybdenum-rhenium alloy or a tungsten-rhenium alloy to provide the guidewire 100 with desirable shape retention capabilities.

[0074] In a further embodiment, the guidewire can include a malleable structure 230 without a marker coil 190 (FIG. 3D).

[0075] It should be noted that guidewire 100 is not limited to the examples of FIGS. 3A-3D, and guidewire 100 can have other configurations in other embodiments. In other embodiments, guidewire 100 can include more than two segments. For example, in other embodiments, guidewire 100 can include more than two segments connected in series along the longitudinal axis of guidewire 100. Also, in other embodiments, at least one of the segments can have multiple layers rather than a single layer.

[0076] In further embodiments, the proximal segment 300 and the distal segment 120 of the guidewire 100 can be made from the same raw material. FIG. 4 illustrates a guidewire 100 according to some embodiments. The guidewire 100 includes a shaft 110 having a proximal end 112, a distal end 114, and a body 116 extending from the proximal end 112 to the distal end 114. The body 116 of the shaft 110 includes a distal segment 120 having a plurality of different cross sections along the length of the distal segment 120. At least the outer portion 130 of the body 106 proximal to the distal segment 120 is made of a material having a shear modulus of at least 13,000 ksi. By way of non-limiting example, the material of the outer portion 130 of the body is a molybdenum-rhenium alloy or a tungsten-rhenium alloy.

[0077] In the illustrated embodiment, shaft 110 also includes a proximal segment 300, with proximal segment 300 and distal segment 120 being made from the same material. In some embodiments, the material of proximal segment 300 and distal segment 120 may be a molybdenum-rhenium alloy or a tungsten-rhenium alloy. As a result of using portions of the same raw material to make segments 300, 120 of shaft 110, as shown by the cross-hatched cross section, inner portion 330 and outer portion 130 of segment 300 and segment 120 have a unitary construction.

[0078] As shown, the proximal segment 300 and the distal segment 120 comprise a single layer and include a first portion 301, a second portion 302, a third portion 304, a fourth portion 306 and a fifth portion 308. The fifth portion 308 has a smaller cross-sectional dimension compared to the cross-sectional dimension of the third portion 304, which transitions to the larger cross-sectional dimension of the third portion 304 through the fourth (middle) portion 306. Similarly, the third portion 304 has a smaller cross-sectional dimension compared to the cross-sectional dimension of the first portion 301, which transitions to the larger cross-sectional dimension of the first portion 301 through the second (middle) portion 302. Such a configuration is advantageous because it provides a gradually softer section from proximal to distal. As a result, the distal segment 120 is softer compared to the remainder of the body 116, with the distal portion 308 providing the softest section and allowing it to flex or bend more easily. In other embodiments, the distal segment 120 may include more or fewer portions than those described above.

[0079] In some embodiments, portion 308 can be compressed to form an elongated cross-sectional shape for portion 308. For example, in one embodiment, portion 308 can have a circular cross-sectional shape, and portion 308 can be compressed either into a planar configuration having an elongated cross-sectional shape, or into another non-circular cross-sectional shape. This feature is advantageous because it provides a bias for portion 308 in a bending direction. Compression of portion 308 can be achieved in some embodiments by pressing portion 308.

[0080] In the illustrated embodiment, the guidewire 100 also includes a sleeve 180 disposed about the distal end 114 of the shaft 110. As illustrated, the sleeve 180 has a blunt tip 182. The distal end 114 of the shaft 110 is coupled to the blunt tip 182. The sleeve 180 may be any tubular member and may be made from any material, such as a metal, a polymer, or the like. In some embodiments, the sleeve 180 may be made from Nitinol. The sleeve 180 may have multiple slots and / or openings to increase the flexibility of the sleeve 180. By way of non-limiting example, the sleeve 180 may be implemented using a slotted hypotube, a coiled sleeve, a tungsten-loaded polymer sleeve, or a combination thereof.

[0081] As shown, guidewire 100 also includes a marker coil 190 disposed within sleeve 180. Marker coil 190 is coupled to tip 182. In some embodiments, marker coil 190 may also be coupled to the wall of sleeve 180. In other embodiments, the proximal end of marker coil 190 may be secured to distal segment 120 (e.g., at any location proximal to portion 308, such as portion 306, portion 304, or portion 302). Securement may be accomplished using adhesives, welding, mechanical connectors, fusion, or the like. In other embodiments, marker coil 190 may form at least a portion of sleeve 180 or may form the entirety of sleeve 180. In further embodiments, guidewire 100 may not include a marker coil 190.

[0082] Guidewire 100 of FIG. 4 is advantageous because it provides an optimal combination of moldability, shape retention, and torque transmission. Because the entire shaft 110 of guidewire 100 is made from the same material (e.g., a single raw material), the resulting shaft 110 can have a small profile (e.g., a smaller profile than in the embodiment of FIGS. 1-3). As such, guidewire 100 can be used to access smaller blood vessels, such as the distal blood vessels of the brain, thereby reaching more aneurysms that were previously inaccessible. Distal portion 308 provides guidewire 100 with a kink-resistant and soft distal end. Distal portion 308 and / or portion 304 may be moldable during use to provide the desired shape retention (without the aid of a malleable structure). However, in other embodiments, guidewire 100 can optionally further include a malleable structure to enhance shape retention, similar to those described above. Additionally, the relatively high shear modulus of the molybdenum-rhenium or tungsten-rhenium alloy shaft 110 provides desirable torque transmission characteristics, and the axial stiffness of the molybdenum-rhenium or tungsten-rhenium alloy shaft 110 also provides desirable pushability for the guidewire 100.

[0083] It should be noted that the materials for making the shaft 110 of the guidewire 100 should not be limited to the above examples, and the shaft 110 can be made of other materials in other embodiments. For example, in other embodiments, the shaft 110 of the guidewire 100 can be made of other materials as long as the desired torque transmission is achieved. In other embodiments, the shaft 110 can be made of any material having a Young's modulus (in annealed condition) of at least 6000 ksi, more preferably at least 30000 ksi, and even more preferably at least 40000 ksi. Also, in other embodiments, the shaft 110 can be made of any material having an ultimate tensile strength (in annealed condition) of at least 100 ksi, more preferably at least 200 ksi, and even more preferably at least 300 ksi. As non-limiting examples, specific materials that can be used include, but are not limited to, Mo-47.5Re, W-25Re, SS304, and the like.

[0084] Further, it should be noted that the shaft 110 of the guidewire 100 may have different dimensions in different embodiments. For example, in some embodiments, the shaft 110 of the guidewire 100 may have an overall length of 50 inches to 100 inches, e.g., 70 inches to 90 inches. Also, in some embodiments, the distal segment 120 may have a length of 5 inches to 30 inches, e.g., 10 inches to 25 inches, or 12 inches to 20 inches. Furthermore, in some embodiments, the distal portion 150 / 216 / 308 may have a length of 0.3 inches to 1 inch, e.g., 0.5 inches to 0.8 inches. In some embodiments where the distal portion 150 / 216 / 308 is pressed, the pressed distal portion may have a portion having a constant width, and the portion may have a longitudinal length of at least 0.3 inches, e.g., at least 0.4 inches. Additionally, in some embodiments, the distal segment 120 can have a cross-sectional dimension (e.g., diameter) anywhere from 0.04 mm to 0.5 mm, and the distal portion 150 / 216 / 308 can have a cross-sectional dimension (e.g., diameter) anywhere from 0.004 mm to 0.001 mm. In other embodiments, the distal segment 120 and / or the distal portion 150 / 216 / 308 can have dimensions different than those listed above.

[0085] Additionally, the number of distinct cross sections along the length of the distal segment 120 is not limited to the examples provided above, in other embodiments the number of distinct cross sections along the length of the distal segment 120 may be greater or less than those described herein.

[0086] Further, in one or more embodiments described herein, a portion of segment 120 can have a flat portion. For example, portion 150 (embodiment of FIG. 1), portion 216 (embodiment of FIG. 2), or portion 308 (embodiment of FIG. 3 or FIG. 4) can be pressed to create the flat portion. Also, in some embodiments, the flat portion of segment 120 can include one or more openings extending through the thickness of the flat portion. This feature is advantageous because it can help guidewire 100 achieve a soft distal end without compromising other performance properties of guidewire 100, such as moldability and / or shape retention. FIG. 5 shows guidewire 100 including flat portion 400 having opening 402. In the illustrated embodiment, flat portion 400 can be created by pressing the distal end of a shaft, such as shaft 110 described with reference to any of the embodiments of FIGS. 1-4. As previously discussed, the shaft 110 includes a proximal end 112, a distal end 114, and a body 116 extending from the proximal end 112 to the distal end 114. The body 116 of the shaft 110 includes a distal segment 120 having a number of different cross-sections along the length of the distal segment 120. In other embodiments, the shaft including the flattened portion 400 may be any elongated member, such as a core wire. The elongated member may have the same cross-sectional dimension along the length of the elongated member, or may have different cross-sectional dimensions along the length of the elongated member.

[0087] As shown in FIG. 5, the opening 402 in the flat portion 400 extends through the thickness of the flat portion 400. The flat portion 400 has a long side 404 parallel to the longitudinal axis 410 of the flat portion 400. The opening 402 is in the form of an elongated slot and has a long side 406 parallel to the long side 404 of the flat portion 400. The opening 402 in the flat portion 400 is advantageous because it reduces the cross-sectional properties (such as the moment of inertia) of the flat portion 400. Since the bending stiffness of the flat portion 400 depends on the moment of inertia of the cross section of the flat portion 400, by reducing the moment of inertia of the cross section of the flat portion 400, the bending stiffness of the flat portion 400 is correspondingly reduced. Thus, the opening 402 in the flat portion 400 has the advantage that it can make the flat portion 400 more flexible. The dimensions of the opening 402 can be configured to achieve the desired stiffness of the flat portion 400.

[0088] In the illustrated embodiment, guidewire 100 also includes a tapered portion 412 proximal to flat portion 400. Guidewire 100 also includes a cylindrical portion 414 proximal to tapered portion 412. In some embodiments, cylindrical portion 414, tapered portion 412 and flat portion 400 may be a portion of a shaft (e.g., a portion of segment 120 of shaft 110).

[0089] In some embodiments, the flat portion 400 can be bent to form a curved shape and is configured to retain the curved shape after the flat portion 400 is bent. In other embodiments, the flat portion 400 can be made from a material that allows the flat portion 400 to bend elastically such that the flat portion 400 can return to its original shape after being bent.

[0090] In other embodiments, instead of having a single opening 402, the flat portion 400 can include a series of openings 402 arranged along the longitudinal axis 410 of the flat portion 400 (FIG. 6). As shown, each of the series of openings 402 is a rectangular slot extending in the thickness direction of the flat portion 400. Alternatively, each of the series of openings 402 can be a circular slot extending in the thickness direction of the flat portion 400 (FIG. 7). The openings 402 can have other shapes in other embodiments. Additionally, in other embodiments, the shapes and / or dimensions of the openings 402 in the flat portion 400 can be different. For example, the flat portion 400 can have a first opening 402 having a first shape and a second opening 402 having a second shape that is different from the first shape.

[0091] 6 and 7, the openings 402 are disposed in a row along the longitudinal axis 410 of the planar portion 400. In other embodiments, the openings 402 may be in multiple rows disposed along the longitudinal axis 410, where the openings 402 are disposed in a staggered arrangement, as shown in FIG.

[0092] It should be noted that the number of openings 402, the size of openings 402, the shape of openings 402, and the arrangement of openings 402 are not limited to the illustrated example. In other embodiments, the number of openings 402, the size of openings 402, the shape of openings 402, the arrangement of openings 402, or any combination thereof can be selected or optimized to achieve a desired softness and / or shape retention ability of the distal end of guidewire 100 depending on a particular application or requirement. Also, in some embodiments, the desired shape retention characteristics of the distal end of guidewire 100 can be achieved by setting the thickness of flat portion 400 of guidewire 100. For example, to increase the shape retention ability of the distal end of guidewire 100, in some embodiments, flat portion 400 can be made thicker.

[0093] In any of the embodiments of Figures 5-8, guidewire 100 may include other components, such as those similarly described with reference to Figures 1-4. For example, as shown in Figure 9, in other embodiments, guidewire 100 in any of the embodiments of Figures 5-8 may also include a sleeve 180 disposed around at least a portion of segment 120. A side view of flat portion 400 having opening 402 extending through the thickness of flat portion 400 is also shown. Sleeve 180 may be made from any material, including but not limited to Nitinol. In some implementations, sleeve 180 may include one or more slots extending partially or completely through the thickness of the wall of sleeve 180. In one implementation, sleeve 180 may be a slotted Nitinol sleeve. Guidewire 100 may also include a blunt tip 182 to which segment 120 and / or sleeve 180 are attached. Guidewire 100 may further include a coil 190 disposed around segment 120. Coil 190 is disposed between segment 120 (e.g., flat portion 400 of segment 120) and sleeve 180. In some embodiments, coil 190 can be made from a radiopaque material such that coil 190 can function as a radiopaque coil. In one embodiment, coil 190 can be made from platinum tungsten. This is advantageous because the soft radiopaque material of coil 190 can further increase the softness of the distal tip of the guidewire. In other embodiments, coil 190 can be made from other materials.

[0094] Additionally, in one or more embodiments described herein, the guidewire 100 can also include a radiopaque marker coupled to the flat portion 400 of the segment 120. For example, the radiopaque marker can be coupled to an opening 402 in the flat portion 400. FIGS. 10A-10H illustrate a method of manufacturing a guidewire including a flat portion and a radiopaque marker coupled to the flat portion. First, a raw wire 500 is provided (FIG. 10A). In some embodiments, the raw wire 500 has a circular cross-section. In other embodiments, the raw wire 500 can have other cross-sectional shapes, such as a square, oval, hexagon, octagon, etc. The raw wire 500 is then ground, cut, and / or polished to create a shaft 510 having different cross-sectional dimensions along the longitudinal axis of the shaft 510 (FIG. 10B). In other embodiments, the shaft 510 having different cross-sectional dimensions along the longitudinal axis of the shaft 510 is created using any of the techniques described with reference to FIGS. 1F, 2F, or 3A. In further embodiments, the creation of different cross-sectional dimensions along the longitudinal axis of the shaft 510 is optional, and the shaft 510 can have a uniform cross-sectional dimension along the longitudinal axis of the shaft 510. A portion of the shaft 510 can then be pressed to create a flat portion 400 (FIG. 10C). The created flat portion 400 has a first major surface and a second major surface opposite the first major surface. An opening 402 can then be created that runs through the thickness of the flat portion 400. The opening 402 can be created, in some embodiments, by cutting (e.g., laser cutting, mechanical cutting, etc.) or drilling the flat portion 400 (FIG. 10D). FIG. 10E shows a side cross-sectional view of the guidewire 100, specifically showing the opening 402 running through the thickness of the flat portion 400. A radiopaque marker 530 can then be inserted into the opening 402 in the flat portion 400, as shown in FIG. 10F.In the illustrated embodiment, the radiopaque marker 530 has a first portion 532 abutting the first side of the flat portion 400 and a second portion 534 configured (e.g., sized and / or shaped) for placement within the opening 402 of the flat portion 400. After the second portion 534 of the radiopaque marker 530 is placed within the opening 402, a third portion 536 of the radiopaque marker 530 extending from the second portion 534 is placed on the opposite side of the flat portion 400. The third portion 536 of the radiopaque marker 530 can then be pressed to flatten the third portion 536. The flattened third portion 536 abuts the second side of the flat portion 400, thereby securing the radiopaque marker 530 to the second side of the flat portion (FIG. 10G). As shown, a first portion 532 of the radiopaque marker 530 has a first cross-sectional dimension, a second portion 534 of the radiopaque marker 530 has a second cross-sectional dimension, and a third portion 536 of the radiopaque marker 530 has a third cross-sectional dimension, the first cross-sectional dimension being greater than the second cross-sectional dimension, and the third cross-sectional dimension being greater than the second cross-sectional dimension. Figure 10H shows a top / plan view of the flat portion 400 of the guidewire 100, and in particular, how the radiopaque marker 530 is secured to the flat portion 400.

[0095] In other embodiments, multiple openings 402 (as shown in the examples of Figures 6-8) can be formed in the planar portion 400. In such cases, multiple radiopaque markers 530 can be secured to the planar portion 400 using the techniques described with reference to Figures 10A-10H.

[0096] In other embodiments, instead of securing the radiopaque markers 530 to both sides of the flat portion 400, other techniques can be utilized to secure the radiopaque markers 530 to the flat portion 400. FIG. 11 illustrates another flat portion 400 of a segment of a guidewire 10. The flat portion 400 may be a pressed core wire, as previously described. As illustrated, the flat portion 400 has a first major surface 600 and a second major surface 602 opposite the first major surface 600. The flat portion 400 includes a first radiopaque marker 610 secured on the first major surface 600 of the flat portion 400 and a second radiopaque marker 612 secured on the second major surface 602 of the flat portion 400. In other embodiments, the second radiopaque marker 612 is optional, and the guidewire 100 may not include the second radiopaque marker 612.

[0097] 11 , each of radiopaque marker 610 and radiopaque marker 612 is a planar marker having a width the same as the width of flat portion 400. In other embodiments, radiopaque marker 610 and / or radiopaque marker 612 can have a width that is less than the width of flat portion 400. In further embodiments, radiopaque marker 610 and / or radiopaque marker 612 can have a width that is greater than the width of flat portion 400.

[0098] Various techniques can be employed to secure the markers 610 and / or markers 612 onto the flat portion 400. For example, in some embodiments, the markers 610 and / or markers 612 can be plated onto the flat portion 400. In other embodiments, the markers 610 and / or markers 612 can be secured onto the flat portion 400 by adhesives. In further embodiments, the markers 610 and / or markers 612 can be applied onto the flat portion 400 by material deposition techniques. For example, the markers 610 and / or markers 612 can be achieved by depositing (e.g., electroplating) a radiopaque material onto the surface of the flat portion 400. The radiopaque material can be Au, Pt, or other materials. In other embodiments, the flat portion 400 can be immersed in a solution of a radiopaque material, which is then cured to form radiopaque markers circumferentially disposed around the flat portion 400. In such a case, markers 610 and 612 on either side of flat portion 400 are part of a circumferential radiopaque marker that surrounds flat portion 400. Markers 610 and / or markers 612 are advantageous because, in addition to being radiopaque for imaging purposes, they also provide shape-retaining properties for flat portion 400. This feature may thus eliminate the need for a separate bendable structure (with shape-retaining properties) between the guidewire shaft and the guidewire outer sleeve.

[0099] In other embodiments, instead of having only one radiopaque marker on one side of the flat portion 400 of the guidewire 100, the flat portion 400 may have a first plurality of radiopaque markers 610 secured to a first major surface 600 of the flat portion 400 (FIG. 12). The first plurality of radiopaque markers 610 are arranged in a row along the longitudinal axis of the flat portion 400. Each of the radiopaque markers 610 are spaced apart from one another. As shown, the guidewire 100 also includes a second plurality of radiopaque markers 612 secured to a second major surface 602 of the flat portion 400. The second plurality of radiopaque markers 612 are arranged in a row along the longitudinal axis of the flat portion 400. Each of the radiopaque markers 612 are spaced apart from one another. In other embodiments, the second plurality of radiopaque markers 612 on the second major surface 602 of the flat portion 400 is optional, and the guidewire 100 may not include the second plurality of radiopaque markers 612. Various techniques may be employed to secure the markers 610 and / or markers 612 onto the flat portion 400. For example, in some embodiments, the markers 610 and / or markers 612 may be plated onto the flat portion 400. In other embodiments, the markers 610 and / or markers 612 may be secured onto the flat portion 400 by an adhesive. In further embodiments, the markers 610 and / or markers 612 may be applied onto the flat portion 400 by material deposition techniques. For example, the markers 610 and / or markers 612 may be achieved by selectively depositing a radiopaque material onto the surface of the flat portion 400 by photolithography or other processes. As shown in FIG. 12, the markers 610 and / or markers 612 are in the form of radiopaque strips. Markers 610 and / or markers 612 are advantageous because, in addition to being radiopaque for imaging purposes, they can also act as stress concentrators and help flat portion 400 retain its shape.In other embodiments, the markers 610 and / or markers 612 may not be in the form of strips, and other patterns of markers 610 / 612 may be used.

[0100] In the above embodiment, the flat portion 400 is described as having one or more openings to reduce the stiffness of the flat portion 400. In other embodiments, other techniques may be employed to reduce the stiffness of the flat portion 400. For example, in other embodiments, the flat portion 400 may include one or more grooves 700 on the outer surface of the flat portion 400 (FIG. 13). The grooves 700 may be implemented as patterned grooves in some embodiments. The one or more grooves 700 reduce the cross-sectional dimension of the flat portion 400, thereby reducing the stiffness (e.g., bending stiffness) of the flat portion 400. In other embodiments, the flat portion 400 may include both one or more openings, such as the openings 402 described with reference to FIGS. 5-10, and one or more grooves 700 to achieve a desired stiffness of the flat portion 400. In further embodiments, the guidewire 100 of FIG. 13 may also include one or more markers secured to the flat portion 400.

[0101] Further, in one or more embodiments described herein, instead of having one flat portion 400, the segment 120 of the guidewire 100 can include multiple flat portions 400 (FIG. 14). In some embodiments, the flat portions 400 can be created by pressing multiple portions of a core wire spaced apart from one another. As a result, each flat portion 400 can have a flat or planar configuration, with adjacent flat portions 400 connected to one another via a cylindrical portion of the core wire. That is, a portion of the core wire between adjacent flat portions 400 serves as a connecting portion connecting adjacent flat portions 400. The connecting portion and adjacent flat portions can have an integrated configuration, since both are made of the same core wire. The flat portions 400 can have the same thickness in some embodiments. In other embodiments, the flat portions 400 can have different respective thicknesses. The number of flat portions 400, the thickness of the flat portions 400, the spacing between the flat portions 400, or any combination thereof can be selected or optimized to achieve a desired softness and / or shape retention ability of the distal end of the guidewire 100. In some embodiments, guidewire 100 of FIG. 14 may also include one or more markers affixed to one or each of flat portions 400.

[0102] It should further be noted that the marker 530 described above is not limited to having a planar configuration, and the manner in which the marker 530 is secured to the shaft is not limited to the examples described above. In other embodiments, the marker 530 can have a different shape and / or can be secured to the shaft in other ways. For example, as shown in FIG. 15, in some embodiments, the marker 530 of the guidewire 100 can be a radiopaque coil 530 that surrounds at least a portion of the segment 120 of the shaft of the guidewire 100. The portion of the segment 120 includes opposing faces 800, 802 having a recess 810 along each of the faces to allow the radiopaque coil 530 to be screwed onto the portion of the segment 120. In some embodiments, the portion of the segment 120 surrounded by the radiopaque coil 530 can be a flat portion (e.g., the flat portion 400 described herein). In such a case, the recess 810 can be a groove that extends through the thickness of the flat portion 400. The recess 810 may be accomplished as a notch in some embodiments. In other embodiments, the portion of the segment 120 surrounded by the radiopaque coil 530 may be another portion of the segment 120 proximal to the flat portion 400. In further embodiments, the segment 120 surrounded by the radiopaque coil 530 may not be a flat portion. Instead, the segment 120 surrounded by the radiopaque coil 530 may be a non-flattened portion of the core wire or shaft. The technique shown in FIG. 15 for attaching the radiopaque coil 530 to the segment 120 is advantageous because it provides mechanical interaction between the segment 120 and the radiopaque coil 530 while also conserving space within the outer distal sleeve of the guidewire 100.

[0103] In any of the embodiments of Figures 10-15, the guidewire 100 may include other components, such as those similarly described with reference to Figures 1-4. For example, as similarly described with reference to Figure 9, in other embodiments, the guidewire 100 of any of the embodiments of Figures 10-15 may also include a sleeve 180 disposed around at least a portion of the segment 120. The sleeve 180 may be made of any material, including but not limited to Nitinol. In some implementations, the sleeve 180 may include one or more slots that extend partially or completely through the thickness of the wall of the sleeve 180. In one implementation, the sleeve 180 may be a slotted Nitinol sleeve. The guidewire 100 may also include a blunt tip 182 to which the segment 120 and / or the sleeve 180 are attached. The guidewire 100 may further include a coil 190 disposed around at least a portion of the segment 120. Coil 190 is disposed between segment 120 (e.g., flat portion 400 of segment 120) and sleeve 180. In some embodiments, coil 190 can be made from a radiopaque material such that coil 190 can function as a radiopaque coil. In one embodiment, coil 190 can be made from platinum tungsten. This is advantageous because the soft radiopaque material of coil 190 can further increase the softness of the distal tip of the guidewire. In other embodiments, coil 190 can be made from other materials.

[0104] Also, in any of the embodiments described herein, guidewire 100 may be provided as a portion of a medical device. For example, the medical device may include a catheter and guidewire 100, the catheter including a lumen for receiving guidewire 100. By way of non-limiting example, the medical device may be a microcatheter, a balloon catheter, a stent delivery catheter, a catheter for removing an obstruction in a blood vessel, a delivery catheter for guidewire 100, etc.

[0105] In one method of using guidewire 100, a physician first bends a distal segment of guidewire 100 into a desired shape depending on the geometry of the anatomy that guidewire 100 is to access. For example, the distal segment of guidewire 100 can be bent to have an L-shape, a C-shape, a U-shape, an S-shape, a shape with two or more curves in different planes, etc. Guidewire 100 is then placed into a delivery catheter. An incision is then made in the patient's skin. The delivery catheter with guidewire 100 therein is inserted through the incision into the patient's blood vessel. The delivery catheter and guidewire 100 can be advanced distally until the distal end of guidewire 100 and / or the delivery catheter reaches the target site. The target site can be anywhere within the patient's body, such as a blood vessel in a limb, a blood vessel in the torso, a blood vessel in the neck, a blood vessel in the head, etc. As the delivery catheter is advanced distally, it houses guidewire 100. When the delivery catheter reaches a location within the patient where the curved shape of the distal segment of the guidewire 100 is required for access, at least a portion of the distal segment can be deployed out of the delivery catheter, allowing the distal segment to assume its curved shape. The curved shape of the distal segment of the guidewire 100 guides the guidewire 100 in a desired direction, thereby allowing the guidewire 100 and delivery catheter to be advanced distally into a desired passageway. The guidewire 100 described herein is advantageous because it can retain the curved shape of the distal segment of the guidewire 100, and the curved shape does not return to a pre-bend configuration even after the distal segment has traversed different paths within blood vessels having different curvatures (or even after the curved distal segment is placed within a tube, such as a delivery tube). The guidewire 100 is also advantageous because the enhanced torque transmission of the guidewire 100 allows the physician to effectively rotate the guidewire 100, and allows the physician to push the guidewire 100 distally within the patient's body without kinking it.

[0106] The embodiments of guidewire 100 described herein have a desired torqueability, a desired shape retention ability, a desired pushability, or any combination thereof. In some embodiments, a desired torqueability is considered to be achieved by guidewire 100 when a twisting or torque motion applied at the proximal end about the longitudinal axis of guidewire 100 to rotate the proximal end of guidewire 100 (or shaft 110) by an angle P results in turning the distal end of guidewire 100 by an angle D that is at least 80% of P, more preferably at least 90% of P, or even more preferably at least 95% of P (e.g., 100% of P, which means that the distal end of guidewire 100 has a 1:1 response with respect to torque applied at the proximal end of guidewire 100). Additionally, in some embodiments, a desired shape retention ability is considered to be achieved by guidewire 100 if a curved segment having a curvature is able to retain at least 70% of its curvature after being placed within a tube and pushed out of the tube, more preferably at least 80% of its curvature, and even more preferably at least 90% of its curvature. Additionally, in some embodiments, a desired pushability may be achieved if guidewire 100 does not kink during advancement within a blood vessel.

[0107] The following items are exemplary features of the embodiments described herein. Each item may be an embodiment in itself or a part of an embodiment. One or more items described below may be combined with one or more other items in an embodiment.

[0108] Item 1: A guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment being coupled to the blunt tip, and the shaft body segment including a flat portion having one or more openings extending through a thickness of the flat portion.

[0109] Item 2: The opening or openings include only one elongated slot extending through the thickness of the planar portion.

[0110] Item 3: The flat portion has a long side parallel to the longitudinal axis of the guidewire and the slot has a long side parallel to the long side of the flat portion.

[0111] Item 4: The opening or openings include a series of openings arranged along the longitudinal axis of the planar portion.

[0112] Item 5: Each of the series of openings is a rectangular slot that runs through the thickness of the planar portion.

[0113] Item 6: Each of the series of openings is a circular slot that extends through the thickness of the planar portion.

[0114] Item 7: The one or more apertures comprise a row of apertures arranged in a staggered array.

[0115] Item 8: The guidewire further includes a radiopaque marker extending through one of the one or more openings.

[0116] Item 9: The radiopaque marker includes a first portion abutting the first side of the flat portion, a second portion within one of the one or more openings, and a third portion abutting the second side of the flat portion, the second side being opposite the first side of the flat portion.

[0117] Item 10: A first portion of the radiopaque marker has a first cross-sectional dimension, a second portion of the radiopaque marker has a second cross-sectional dimension, and a third portion of the radiopaque marker has a third cross-sectional dimension, the first cross-sectional dimension being greater than the second cross-sectional dimension, and the third cross-sectional dimension being greater than the second cross-sectional dimension.

[0118] Item 11: The flat portion includes a pressed core wire.

[0119] Item 12: The guidewire further includes a coil disposed between the flat portion and the sleeve.

[0120] Item 13: The coil is made from a radiopaque material.

[0121] Item 14: The coil is made from platinum tungsten.

[0122] Item 15: The sleeve is made from Nitinol.

[0123] Item 16: The sleeve includes a plurality of slots.

[0124] Item 17: The body of the shaft includes a tapered portion proximal to the flat portion.

[0125] Item 18: The body of the shaft includes a cylindrical portion proximal to the tapered portion.

[0126] Item 19: The flat portion is configured to be bendable to form a curved shape and to retain the curved shape after the flat portion is bent.

[0127] Item 20: The segment also includes an additional flat portion distal to the flat portion.

[0128] Item 21: The segment also includes a connecting portion that connects the flat portion and the additional flat portion, and the connecting portion, the flat portion and the additional flat portion have an integral configuration.

[0129] Item 22: The medical device includes a catheter and a guidewire, the catheter including a lumen for accommodating the guidewire.

[0130] Item 23: A guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment coupled to the blunt tip, the shaft body segment including a flat portion having a first major surface and a second major surface opposite the first major surface, the flat portion including one or more radiopaque markers secured to the first major surface.

[0131] Item 24: The one or more radiopaque markers include a first flat marker having a width equal to the width of the flat portion.

[0132] Item 25: The guidewire further includes a second planar marker fixed on a second major surface of the planar portion.

[0133] Item 26: The one or more radiopaque markers include a first plurality of radiopaque markers spaced apart from one another.

[0134] Item 27: The first plurality of radiopaque markers are aligned along the longitudinal axis of the planar portion.

[0135] Item 28: The guidewire further includes a second plurality of radiopaque markers spaced apart from one another and fixed on a second major surface of the planar portion.

[0136] Item 29: The planar portion also includes one or more radiopaque markers fixed on the second major surface.

[0137] Item 30: A guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the shaft body including at least a segment surrounded by the sleeve, the segment coupled to the blunt tip, the shaft body segment including a flat portion having an outer surface, the flat portion including a plurality of grooves on the outer surface.

[0138] Item 31: A guidewire includes a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end, a blunt tip, and a sleeve, the body of the shaft including at least a segment surrounded by the sleeve, the segment coupled to the blunt tip, the guidewire further including a radiopaque coil surrounding at least a portion of the segment, the portion of the segment including opposing faces having a recess along each of the faces to allow the radiopaque coil to be screwed onto the portion of the segment.

[0139] Item 32: The portion of the segment includes a flat portion.

[0140] Item 33: The segment includes a flat portion, the portion of the segment being proximal to the flat portion.

Claims

1. A guidewire comprising: a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end; With a blunt tip, and a sleeve. the shaft body includes a flat portion having one or more openings extending through a thickness of the flat portion, the flat portion being surrounded by the sleeve and coupled to the blunt tip; the flat portion includes a pressed core wire; the one or more openings include an elongated slot extending through a thickness of the planar portion; A guidewire characterized in that the shaft has torque transmission capability such that when a torque motion is applied at the proximal end to rotate around the longitudinal axis direction by an angle P, the shaft rotates at the distal end around the longitudinal axis direction by an angle D that is at least 80% of P.

2. 2. The guidewire of claim 1, A guidewire, wherein the flattened portion has a long side parallel to a longitudinal axis of the guidewire, and the slot has a long side parallel to the long side of the flattened portion.

3. 2. The guidewire of claim 1, The one or more openings include a series of rectangular slots extending through a thickness of the planar portion, the elongated slot being one of the series of rectangular slots.

4. A guidewire comprising: a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end; With a blunt tip, and a sleeve. the shaft body includes a flat portion having one or more openings extending through a thickness of the flat portion, the flat portion being surrounded by the sleeve and coupled to the blunt tip; the flat portion includes a pressed core wire; the one or more openings include a series of circular openings extending through a thickness of the planar portion; The series of circular openings are aligned along a longitudinal axis of the guidewire, the longitudinal axis extending through a center of the planar portion.

5. 2. The guidewire of claim 1, The one or more apertures comprise a row of apertures arranged in a staggered arrangement.

6. A guidewire comprising: a shaft having a proximal end, a distal end, and a body extending from the proximal end to the distal end; With a blunt tip, and a sleeve. the shaft body includes a flat portion having one or more openings extending through a thickness of the flat portion, the flat portion being surrounded by the sleeve and coupled to the blunt tip; the flat portion includes a pressed core wire; The guidewire, a radiopaque marker extending through one of the one or more openings, the radiopaque marker having a first portion abutting a first side of the flat portion, a second portion within one of the one or more openings, and a third portion abutting a second side of the flat portion, the second side being opposite the first side of the flat portion.

7. 7. The guidewire according to claim 6, a first portion of the radiopaque marker having a first cross-sectional dimension, a second portion of the radiopaque marker having a second cross-sectional dimension, and a third portion of the radiopaque marker having a third cross-sectional dimension; the first cross-sectional dimension is greater than the second cross-sectional dimension; The guidewire, wherein the third cross-sectional dimension is greater than the second cross-sectional dimension.

8. The guidewire according to any one of claims 1 to 7, The guidewire further comprises a coil disposed between the flat portion and the sleeve.

9. The guidewire according to any one of claims 1 to 8, The guidewire, wherein the sleeve has a plurality of slots.

10. The guidewire according to any one of claims 1 to 9, The body of the shaft comprises: a tapered portion proximal to the flat portion; and a cylindrical section proximal to the tapered section.

11. The guidewire according to any one of claims 1 to 10, A guidewire, characterized in that the flat portion is bendable to form a curved shape and configured to retain the curved shape after the flat portion is bent.

12. 2. The guidewire of claim 1, The body of the shaft comprises: an additional flat portion distal to the flat portion; a connecting portion connecting the flat portion to the additional flat portion, A guidewire, wherein the flat portion, the connecting portion and the additional flat portion have an integral construction.

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