Embolic devices for occluding body lumens

Abstract

To provide medical devices and methods for occluding aneurysms.SOLUTION: An embolic device for placement in a body lumen is provided, the embolic device including an elongated member having a linear configuration when in room temperature, the elongated member being configured to form a first three-dimensional structure in response to body temperature. The elongated member comprises a first segment, a second segment, and a third segment, the second segment being located between the first segment and the third segment. The first segment and the third segment are configured to change their respective shapes in response to the body temperature. The second segment that is located between the first segment and the third segment has a shape that is independent of the body temperature.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001]

[0001] The field of the present disclosure relates to medical devices and methods for occluding body cavities, and more particularly, to medical devices and methods for occluding aneurysms.

Background Art

[0002]

[0002] An aneurysm is an expansion of a blood vessel that can rupture, clot, or dissect, posing a risk to health. Rupture of a cerebral aneurysm causes a stroke, and rupture of an abdominal aneurysm causes shock symptoms. Cerebral aneurysms are usually detected in patients as a result of seizures or bleeding and can result in significant morbidity or mortality.

[0003]

[0003] There are various materials and devices that have been used in the treatment of aneurysms, including platinum and stainless steel microcoils, polyvinyl alcohol sponges (Ivalone), and other mechanical devices. For example, a vascular occlusion device is typically a surgical instrument or implant that is placed within the vasculature of the human body via a catheter and blocks blood flow through the blood vessels that make up that portion of the vasculature or forms such an embolism within an aneurysm originating from the blood vessel by forming an embolism.

[0004]

[0004] When a vascular occlusion device is carried within a catheter, the vascular occlusion device may be elastically bent to conform to the profile of the catheter. This elastic bending of the vascular occlusion device creates various pressure points against the inner surface of the catheter, which can make it more difficult for the vascular occlusion device to advance relative to the catheter and may be undesirable. In some cases, it is necessary to increase the axial force to push the vascular occlusion device distally. Increasing this axial force may cause premature buckling of the vascular occlusion device within the catheter.

[0005]

[0005] Further, the vascular occlusion device may assume a specific three-dimensional shape when deployed outside the catheter. If the deployed vascular occlusion device is too rigid, it may not conform to the shape of the body cavity to be occluded by the vascular occlusion device. On the other hand, if the deployed vascular occlusion device is too soft, the vascular occlusion device may not be able to maintain its shape and may be bent into an undesired shape inadvertently, resulting in the inability to occlude the body cavity.

Summary of the Invention

[0006]

[0006] In an occlusion device for placement within a body cavity, comprising an elongate member having a linear configuration at room temperature, the elongate member being configured to form a first three-dimensional structure in response to body temperature, the elongate member includes a first section, a second section, and a third section, the second section being located between the first section and the third section, the first section and the third section being configured to change their respective shapes in response to body temperature, and the second section located between the first section and the third section having a shape independent of body temperature.

[0007]

[0007] Optionally, the first section is configured to form a first portion of a loop, and the third section is configured to form a second portion of the loop in response to body temperature.

[0008]

[0008] Optionally, in response to body temperature, the first section is configured to form a first loop, and the third section is configured to form a second loop.

[0009]

[0009] Optionally, the first section has a first length, the second section has a second length, the third section has a third length, the second length of the second section is shorter than the first length of the first section, and also shorter than the third length of the third section.

[0010]

[0010] Optionally, the second length of the second section between the first section and the third section is less than 50% of the first length of the first section, and also less than 50% of the third length of the third section.

[0011] Optionally, the elongate member has a distal end and a proximal end opposite the distal end, and the plug device further includes a fourth section that includes the proximal end, the fourth section being martensite when the fourth section is at room temperature and also being martensite when the fourth section is at body temperature.

[0012] Optionally, the first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature.

[0013] Optionally, the second section is martensite when the second section is at room temperature and is also martensite when the second section is at body temperature.

[0014] Optionally, the three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section are part of one of the loops.

[0015] Optionally, the elongate member further includes a fourth section, a fifth section, and a sixth section that are part of another one of the loops, the fifth section being between the fourth section and the sixth section, the fourth section and the sixth section being configured to change their respective shapes in response to body temperature, and the fifth section located between the fourth section and the sixth section having a shape that is independent of body temperature.

[0016] In a plug device for placement within a body cavity, having an elongate member that has a linear configuration when at room temperature, the elongate member being configured to form a first three-dimensional structure in response to body temperature, the elongate member including a first section, a second section, and a third section, the second section being located between the first section and the third section, the first section being martensite when the first section is at room temperature and austenite when the first section is at body temperature, and the second section being martensite when the second section is at room temperature and also being martensite when the second section is at body temperature.

[0017] Optionally, depending on body temperature, the first section is configured to form a first portion of the loop and the third section is configured to form a second portion of the loop.

[0018] Optionally, depending on body temperature, the first section is configured to form a first loop and the third section is configured to form a second loop.

[0019] Optionally, the first section has a first length, the second section has a second length, the third section has a third length, and the second length of the second section is shorter than the first length of the first section and also shorter than the third length of the third section.

[0020] Optionally, the second length of the second section between the first section and the third section is less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

[0021] Optionally, the elongate member has a distal end and a proximal end opposite the distal end, and the plug device further includes a fourth section including the proximal end, and the fourth section is martensite when at room temperature and is also martensite when the fourth section is at body temperature.

[0022] Optionally, the three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section are part of one of the plurality of loops.

[0023] Optionally, the elongate member further includes a fourth section, a fifth section, and a sixth section that are part of another one of the plurality of loops, the fifth section is between the fourth section and the sixth section, and the fourth section and the sixth section are martensite when the fourth section and the sixth section are at room temperature and are austenite when the fourth section and the sixth section are at body temperature, and the fifth section is martensite when the fifth section is at room temperature and is also martensite when the fifth section is at body temperature.

[0024]

[0024] A method of occluding a body cavity performed by a plug device having an elongate member, the elongate member including a first section, a second section, and a third section, the second section being between the first section and the third section, the method including the steps of undergoing a first shape change by the first section of the elongate member in response to body temperature, undergoing a second shape change by the second section of the elongate member in response to a force, and undergoing a third shape change by the third section of the elongate member in response to body temperature.

[0025]

[0025] Optionally, the first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature, the second section is martensite when the second section is at room temperature and also martensite when the second section is at body temperature.

[0026]

[0026] Optionally, in response to body temperature, the first section forms a first portion of a loop and the third section forms a second portion of the loop.

[0027]

[0027] Optionally, in response to body temperature, the first section forms a first loop and the third section forms a second loop.

[0028]

[0028] Optionally, the first section has a first length, the second section has a second length, the third section has a third length, the second length of the second section is shorter than the first length of the first section and also shorter than the third length of the third section.

[0029]

[0029] Optionally, the second length of the second section between the first section and the third section is less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

[0030]

[0030] Optionally, the elongate member has a distal end and a proximal end opposite the distal end, the plug device further including a fourth section including the proximal end, the fourth section being martensite when at room temperature and also martensite when the fourth section is at body temperature.

[0031]

[0031] Optionally, the three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section are part of one of the plurality of loops.

[0032]

[0032] Optionally, the elongate member further includes a fourth section, a fifth section, and a sixth section that are part of another one of the plurality of loops, the fifth section being between the fourth section and the sixth section, and the fourth section and the sixth section being martensite when the fourth section and the sixth section are at room temperature and austenite when the fourth section and the sixth section are at body temperature, and the fifth section being martensite when the fifth section is at room temperature and also martensite when the fifth section is at body temperature.

[0033]

[0033] Other additional aspects and features will become apparent upon reading the following detailed description.

Brief Description of the Drawings

[0034]

[0034] The drawings illustrate the design and utility of embodiments in which like elements are referenced by common reference numerals. These drawings are not necessarily drawn to scale. A more specific description of the embodiments shown in the accompanying drawings is provided to better understand how the above and other advantages and objectives are obtained. These drawings show only exemplary embodiments and should not be considered as limiting the scope of the claims.

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0036]

[0044] Hereinafter, various embodiments will be described with reference to the drawings. Note that the drawings are not drawn to scale, and elements having the same structure or function are denoted by the same reference numeral throughout the drawings. Also note that the drawings are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the present invention or as a limitation of the scope of the present invention. Furthermore, the illustrated embodiments do not necessarily have all the aspects or advantages shown. Aspects or advantages described in connection with a particular embodiment are not necessarily limited to that embodiment, and can be implemented in any other embodiment even if not so illustrated or explicitly described as such.

[0037]

[0045] Figure 1 shows a medical device 10 having a catheter 20 for delivering a plug device 100 into a body cavity. The catheter 20 has a distal end 22, a proximal end 24, and a catheter body 26 extending between the distal end 22 and the proximal end 24. The plug device 100 is housed within the lumen 28 of the catheter 20. The medical device 10 further includes a shaft 30 disposed within the lumen 28 for pushing the plug device 100 out of the lumen 28 of the catheter 20.

[0038]

[0046] As shown in Figure 1, the plug device 100 is made from an elongate member 102 having a distal end 104, a proximal end 106, and a body 108 extending between the distal end 104 and the proximal end 106. The elongate member 102 of the plug device 100 has a linear configuration (e.g., a straight profile) when at room temperature within the catheter 20. The elongate member 102 is configured to form a three-dimensional structure 112 in response to body temperature when the elongate member 102 is delivered outside the catheter 20 within the patient's body (Figure 2).

[0039]

[0047] Figure 3 shows an embodiment of the plug device 100. As illustrated, the elongate member 102 of the plug device 100 has a relatively straight linear configuration at room temperature. This elongate member 102 is configured to form a three-dimensional structure in response to body temperature. Thus, the straight profile of the elongate member 102 within the catheter 20 is mainly due to the elongate member 102 being at room temperature and not mainly due to mechanical correction by the catheter 20. This feature is advantageous as it reduces friction between the elongate member 102 and the inner wall of the catheter 20 and allows the plug device 100 to be easily advanced distally. This feature enables the provision of a longer plug device 100 if desired.

[0040]

[0048] In the illustrated embodiment, the elongate member 102 has a first section 300, a second section 302, and a third section 304. The second section 302 is located between the first section 300 and the third section 304. The first section 300 and the third section 304 are configured to change their respective shapes in response to body temperature. The shape of the second section 302 located between the first section 300 and the third section 304 is independent of body temperature.

[0041]

[0049] Note that the term "body temperature" as used herein may refer to a temperature range such as 95°F to 107°F (35°C to 41.6667°C), more preferably 96°F to 100°F (35.5556°C to 37.7778°C), or even more preferably 97°F to 99°F (36.1111°C to 37.2222°C). Also, as used herein, the term "room temperature" may refer to any temperature different from body temperature. For example, room temperature can be any temperature lower than body temperature. In some embodiments, room temperature can be any temperature at least 10°F lower than body temperature, or at least 20°F lower than body temperature.

[0042]

[0050] In the illustrated embodiment, the first section 300 is martensite when the first section 300 is at room temperature and austenite when the first section 300 is at body temperature. The second section 302 is martensite when the second section 302 is at room temperature and martensite when the second section 302 is at body temperature. The third section 304 is martensite when the third section 304 is at room temperature and austenite when the third section 304 is at body temperature. Thus, the first and third sections 300, 304 are reversible martensite sections such that the first and third sections 300, 304 have a relatively linear profile at room temperature and can change to austenite in response to body temperature. On the other hand, the second section 302 is an irreversible martensite section that can have a relatively linear profile at both room temperature and body temperature.

[0043]

[0051] In the illustrated embodiment, the second section 302 is softer than the first section 300 and the third section 304. As a result, the second section 302 can bend more easily in response to force compared to the first and third sections 300, 304.

[0044]

[0052] It should be noted that as used herein, the term "linear" can be used to describe the delivery shape of the plug device 100 that is linear or curved as long as the delivery shape has a curvature smaller than the curvature of the deployed plug device 100.

[0045]

[0053] As shown in FIG. 4, the elongate member 102 is configured to form a three-dimensional structure 112 having a plurality of loops 400 in response to body temperature after the elongate member 102 is deployed. As shown in the figure, the first section 300, the second section 302, and the third section 304 form part of one of the loops 400. That is, in response to body temperature, the first section 300 is configured to form a first portion of the loop 400, and the third section 304 is configured to form a second portion of the same loop 400.

[0046]

[0054] As shown, the elongate member 102 further includes a fourth section 410, a fifth section 412, and a sixth section 414 that form part of another one of the loops 400. The fifth section 412 is between the fourth section 410 and the sixth section 414. The fourth section 410 and the sixth section 414 are configured to change their respective shapes in response to body temperature. The shape of the fifth section 412 located between the fourth section 410 and the sixth section 414 is independent of body temperature. In some embodiments, the fourth section 410 and the sixth section 414 are martensite when the fourth section 410 and the sixth section 414 are at room temperature, and austenite when the fourth section 410 and the sixth section 414 are at body temperature. The fifth section 412 is martensite when the fifth section 412 is at room temperature and also martensite when the fifth section 412 is at body temperature.

[0047]

[0055] In some embodiments, the elongate member 102 can include a plurality of sets of three sections, and each set of the three sections is configured to form a loop (or other desired curved shape) of the three-dimensional structure 112. In each set of the three sections, the first and last sections are configured to change shape in response to body temperature, and the second section located between the first and third sections has a shape that is independent of body temperature. Thus, when the elongate member 102 is delivered from outside the patient into the patient's body, the elongate member 102 undergoes a temperature change from room temperature to body temperature. As a result, the first and third sections of each set of the elongate member 102 change shape in response to body temperature, and the second section of each set of the elongate member 102 does not respond to body temperature and does not change shape due to body temperature.

[0048]

[0056] In some embodiments, the first section 300 has a first length, the second section 302 has a second length, and the third section 304 has a third length. The second length of the second section 302 is shorter than the first length of the first section 300 and also shorter than the third length of the third section 304. For example, the second length of the second section 203 located between the first section 300 and the third section 304 can be less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

[0049]

[0057] In the above embodiment, the second section 302 is located between the first section 300 and the third section 304, and all three sections 300, 302, 304 are described as being part of one loop. In other embodiments, the second section 302 may be arranged at other positions. For example, in other embodiments, the second section 302 may be arranged near one end of the loop. In that case, the lengths of the first and third sections 300, 304 may be different from each other. As another example, in other embodiments, the second section 302 may be arranged between two loops. In this case, in response to body temperature, the first section 300 is configured to form the first loop, and the third section 304 is configured to form the second loop. The second section 302 located between the two loops (formed by the first and third sections 300, 304) does not change its shape in response to body temperature. Instead, the second section 302 may be configured to change its shape in response to force. In some cases, the second section 302 may be arranged at the inflection point between the two loops.

[0050]

[0058] Also, in other embodiments, instead of having only one irreversible martensite section (e.g., section 302) per loop 400, the plug device 100 may have a plurality of irreversible martensite sections per loop 400.

[0051]

[0059] In one or more embodiments described herein, the plug device 100 can optionally include an additional section at its proximal end. FIG. 5 shows another example of the plug device 100. This plug device 100 is similar to the plug device 100 described with reference to FIGS. 3-4, except that the plug device 100 includes an additional section 500 at its proximal end. As shown in FIG. 5, the plug device 100 includes first, second, and third sections 300, 302, 304, and the description thereof is the same. However, this plug device 100 further includes a fourth section 500 at the proximal end of the elongate member 102. The fourth section 500 does not change shape in response to body temperature. As shown in FIG. 6, when the plug device 100 is exposed to body temperature, most of the length of the elongate member 102 changes shape to form a three-dimensional structure 112. However, the fourth section 500 remains straight and does not change its shape. Instead, the fourth section 500 is configured to change shape in response to a force. For example, when the plug device 100 having the fourth section 500 is delivered to an aneurysm, when the fourth section 500 is pushed out of the catheter 20, the inner wall of the aneurysm, or other parts of the plug device 100 already delivered inside the aneurysm may apply a force to the fourth section 500. As a result, the fourth section 500 will bend. In some embodiments, the fourth section 500 is martensite when the fourth section is at room temperature and is also martensite when the fourth section 500 is at body temperature. Also, in some embodiments, the fourth section 500 is softer than sections having shape memory properties (e.g., the first section 300, the third section 302, etc.). Therefore, the fourth section 500 can bend more easily when an external force is applied. Thereby, depending on the direction and magnitude of the external force, the fourth section 500 can be formed into any shape. In some cases, the fourth section 500 may be configured for the purpose of filling a space within a body cavity such as an aneurysm. In some embodiments, the fourth section 500 may have a length greater than the length of the preceding loop 400. For example, the fourth section 500 can have a length that is 1, 2, 3, or 4 times the length of the section forming the preceding loop 400.

[0052]

[0060] In some embodiments, the fourth section 500 can be made of the same material as the section 302 and can have the same mechanical properties as the section 302. In other embodiments, the fourth section 500 may be softer than the section 302.

[0053]

[0061] In the illustrated embodiment, the loops 400 of the three-dimensional structure 112 are connected at their respective inflection points, whereby adjacent loops 400 can form reverse curvatures. In other embodiments, adjacent loops 400 of the three-dimensional structure 112 may not form reverse curvatures. Further, in other embodiments, instead of loops, the first three-dimensional structure 112 may have other structural elements having a shape other than a loop.

[0054]

[0062] In some embodiments, the curvatures of the loops 400 of the three-dimensional structure 112 can be the same. In other embodiments, one or more of the loops 400 may be different from another one of the loops 400 within the three-dimensional structure 112. For example, in some embodiments, the three-dimensional structure 112 has a first loop 400 having a first curvature and a second loop 400 proximal to the first loop 400, and this second loop 400 can have a second curvature higher than the first curvature of the first loop 400. In other embodiments, the three-dimensional structure 112 has a first loop 400 having a first curvature and a second loop 400 proximal to the first loop 400, and this second loop 400 may have a second curvature lower than the first curvature of the first loop 400. As used herein, "curvature" can be defined as 1 / R, where R can be the minimum radius of curvature associated with the curve.

[0055]

[0063] In some embodiments, the three-dimensional structure 112 has at least two loops 400 (e.g., at least two adjacent loops 400) where the change in each loop dimension does not exceed 10%, preferably does not exceed 5%. For example, in one embodiment, the three-dimensional structure 112 may have loops 400 having the same loop dimensions (e.g., loop width or diameter). In other embodiments, the three-dimensional structure 112 may have loops 400 where each loop dimension differs by more than 10%.

[0056]

[0064] Furthermore, in some embodiments, the loops 400 within the three-dimensional structure 112 have respective loop dimensions that decrease along the length of the elongate member 102 in the distal-to-proximal direction. This feature is advantageous because the elongate member 102 forms a smaller filling structure that is different from the previous one, thereby allowing subsequent filling structures to fit inside the previous one.

[0057]

[0065] In some embodiments, the first portion of the plug device 100 has a first width, and the second portion of the plug device 100 adjacent to the first portion may have a second width that is smaller than the first width. Alternatively or additionally, the first portion of the plug device 100 has a first thickness, and the second portion of the plug device 100 may have a second thickness that is smaller than the first thickness. In one embodiment, the elongate member 102 is in a braided structure, and the second portion of the plug device 100 uses fewer strands of fibers to form the braid of the second portion compared to the number of strands of fibers used to form the braid of the first portion, thereby achieving a narrower width and / or thickness. Alternatively, the second portion of the plug device 100 may be made narrower (or thinner) by cutting or trimming a part of the member used to form the second portion (e.g., using a laser cutter, grinder, etc.). As another alternative, the first and second portions of the plug device 100 may be formed from separate members having different cross-sectional dimensions. In such a case, the members can be fixed to each other using, for example, adhesives, welding, fusing, mechanical couplers, etc. It should be noted that the terms "width" and "thickness" may in some cases refer to the longer and shorter dimensions of a cross-section, such as a rectangular or elliptical cross-section. However, using either of these terms does not mean that the cross-section is an elongated shape. For example, the width or thickness of a cross-section may refer to the cross-sectional dimensions of a circular cross-section, a square cross-section, a hexagonal cross-section, a pentagonal cross-section, etc.

[0058]

[0066] Also, in some embodiments, the angle of the three-dimensional structure 112 (between adjacent loops 400) may gradually decrease from distal to proximal along the length of the elongate member 102. This feature is advantageous as it enables the distal portion of the elongate member 102 to form a first portion of the three-dimensional structure 112 along the perimeter of the body cavity, and the proximal portion of the elongate member 102 to form a second portion of the three-dimensional structure 112 that can fit within the first portion of the three-dimensional structure 112. In one embodiment, the first portion of the elongate member 102 is configured to form a first plurality of loops 400 having a first plurality of angles between adjacent loops of the first plurality of loops 400, and the second portion of the elongate member 102 may be configured to form a second plurality of loops 400 having a second plurality of angles between adjacent loops of the second plurality of loops 400. The first plurality of angles may be the same as each other, and the second plurality of angles may be the same as each other. However, the first plurality of angles can be greater than the second plurality of angles.

[0059]

[0067] As described above, in some embodiments, the elongate member 102 may gradually decrease the angle between adjacent loops from the distal end to the proximal end of the elongate member 102. Thereby, the elongate member 102 can fill the body cavity "from the outside to the inside", such that the outside space within the body cavity is first filled before the inner space of the aneurysm. In other embodiments, the elongate member 102 may gradually increase the angle between adjacent loops from the distal end to the proximal end of the elongate member 102. Thereby, the elongate member 102 can fill the body cavity "from the inside to the outside", such that the inner space within the body cavity is first filled before the external space within the body cavity.

[0060]

[0068] In some embodiments, the elongate member 102 of the plug device 100 can be a braided structure. In one embodiment, the elongate member 102 can be formed by braiding 24 fiber strands. Alternatively, other numbers of fiber strands may be used to form the elongate member. Also, in some embodiments, the proximal portion of the elongate member 102 may be formed using more strands compared to the distal portion of the elongate member 102. In other embodiments, the distal portion of the elongate member 102 may be formed using more strands compared to the proximal portion of the elongate member 102, thereby making the distal portion stiffer compared to the proximal portion.

[0061]

[0069] In other embodiments, the elongate member 102 of the plug device 100 can be a coil. In such a case, the elongate member 102 has a primary shape that is a coil and can be formed by bending the coil to form a desired secondary shape (deployed shape).

[0062]

[0070] In a further embodiment, the elongate member 102 of the plug device 100 may be a solid continuous member. In such a case, the solid continuous member has a linear primary shape and can be bent to form a desired secondary shape (deployed shape).

[0063]

[0071] In one or more embodiments described herein, the length of the elongate member 102 of the plug device 100 can be any of 15 cm to 50 cm, or 25 cm to 45 cm, or 30 to 40 cm. In other embodiments, the length of the elongate member 102 of the plug device 100 may be less than 15 cm or 40 cm or more.

[0064]

[0072] Also, in one or more embodiments described herein, the elongate member 102 of the plug device 100 can be made of any suitable material. By way of non-limiting example, the elongate member 102 of the plug device 100 can be made of Nitinol (trademark), AuPt, stainless steel, platinum, other metals, other alloys, or any combination thereof.

[0065]

[0073] In some embodiments, each previous portion of the elongate member 102 forms a filling structure that can accommodate a subsequent portion of the elongate member 102. Thereby, various layers of the structure can be delivered to the aneurysm in a nested configuration and the aneurysm can be filled from the periphery to the center of the aneurysm. In some embodiments, a first portion of the elongate member 102 has a first set of loops, a second portion of the elongate member 102 proximal to this first portion has a second set of loops, and a third portion of the elongate member 102 proximal to this second portion can have a third set of loops. The first set of loops can have loop widths of the same size or loop widths that decrease in size from distal to proximal. Similarly, the second set of loops can have loop widths that are the same size or that decrease in size from distal to proximal. Also, the third set of loops can have loop widths that are the same size or that decrease in size from distal to proximal. Further, in some embodiments, the first (i.e., distal) loop of a subsequent portion of the elongate member 102 can have a width that is smaller than the width of the last (i.e., proximal) loop of the previous portion of the elongate member 102. Alternatively, in other embodiments, the first (i.e., distal) loop of a subsequent portion of the elongate member 102 can have a width that is larger than the width of the last (i.e., proximal) loop of the previous portion of the elongate member 102.

[0066]

[0074] In one or more embodiments described herein, the embolization device 100 can optionally further include a distal loop at the distal end of the embolization device 100, the distal loop having a diameter that is 75% smaller than the diameter of a loop proximal to the distal loop. As used herein, the "diameter" of a loop does not necessarily mean that the loop is circular, and the term "diameter" can refer to the width of the loop whether the shape is circular or not. For example, the diameter of a loop can, in some cases, refer to the maximum width of the loop.

[0067]

[0075] Also, in one or more embodiments described herein, the plugging device 100 can optionally further include a distal coil at the distal end of the plugging device 100. In one embodiment, when the elongate member 102 of the plugging device 100 is formed from a braid, the distal coil can be formed from one or more strands of the braid. In another embodiment, a separate coil can be provided as the distal coil and attached to the distal end of the elongate member 102.

[0068]

[0076] Furthermore, in one or more embodiments described herein, the plugging device 100 can optionally further include a proximal coil at the proximal end of the plugging device 100. In one embodiment, when the elongate member 102 of the plugging device 100 is formed from a braid, the proximal coil can be formed from one or more strands of the braid. In another embodiment, a separate coil can be provided as the proximal coil and attached to the proximal end of the elongate member 102. This proximal coil can be advantageous as it can provide a rigid transition from the plugging device 100 to the shaft 30.

[0069]

[0077] Also, in one or more embodiments described herein, the proximal portion of the plugging device 100 may have a rigidity (e.g., bending rigidity and / or axial rigidity) different from that of the distal portion of the plugging device 100 (e.g., bending rigidity and / or axial rigidity). In some embodiments, the column strength of the proximal portion of the plugging device 100 can have a column strength different from that of the distal portion of the plugging device 100. For example, the column strength of the proximal portion of the plugging device 100 may be higher than the column strength of the proximal portion of the plugging device 100. This is advantageous because the plugging device 100 can be pushed distally inside the catheter 20 without buckling. The relative differences in column strength and / or rigidity can be achieved by varying the cross-sectional dimensions using metallurgical heat treatment conditions along the length of the elongate member 102 and / or varying the number of strands in the braid structure.

[0070]

[0078] Also, in one or more embodiments described herein, when the elongate member 102 is a braided structure, in order to vary the stiffness along the length of the elongate member 102, the braiding angle of the strands along the length of the member 102 may be varied. For example, in some embodiments, the proximal portion of the elongate member 102 and the distal portion of the elongate member 102 may have the same number of strands, but the braiding angle of the strands in the proximal portion (e.g., the angle formed by the strands with respect to the longitudinal axis of the member 102) is greater than the braiding angle of the strands in the distal portion, thereby making the proximal portion of the elongate member 102 stiffer than the distal portion of the elongate member 102. In other embodiments, the braiding angle of the strands in the distal portion of the elongate member 102 is greater than the braiding angle of the strands in the proximal portion of the elongate member 102, thereby making the second portion of the elongate member 102 softer than the first portion of the elongate member 102. Also, in some embodiments, the braiding angle of the strands may vary gradually along the length of the member 102.

[0071]

[0079] Furthermore, in some embodiments, the three-dimensional structure includes a first plurality of loops 400, where the loop width, loop curvature, braiding width, braiding angle, or any combination thereof of each loop of the first plurality of loops 400 increases or decreases along the length of the elongate member 102 forming the three-dimensional structure 112.

[0072]

[0080] Furthermore, in some embodiments, the three-dimensional structure 112 includes a plurality of loops 400, where the angle between adjacent loops of the plurality of loops 400 increases or decreases along the length of the elongate member 102 forming the three-dimensional structure 112.

[0073]

[0081] Furthermore, it should be noted that the plug device 100 is not limited to the examples described herein, and the plug device 100 may have other configurations in other embodiments. For example, in other embodiments, the plug device 100 may be configured to form other three-dimensional structures different from those described herein.

[0074]

[0082] In a further embodiment, the plug device 100 is not configured to fill the body cavity from the periphery to the center of the body cavity, nor is it configured to fill the body cavity from the center to the periphery of the body cavity. Instead, the plug device can be configured to fill the body cavity from one side of the body cavity to the opposite side. Alternatively, the plug device can be configured to fill the body cavity in a random manner.

[0075]

[0083] Various techniques can be used to form the plug device 100. In some embodiments, the elongate member 102 can be wound around one or more mandrels to form a desired shape. The mandrel can include a plurality of struts configured such that the elongate member 102 wraps around it. The size of the struts determines the loop size of the loops formed. Also, the relative orientation of the struts determines the relative angle between the loops formed. After the elongate member 102 is wound around the mandrel, the elongate member 102 can be chemically treated and / or heat treated to achieve the deployed shape of the elongate member 102 and / or to provide different mechanical properties to different portions of the elongate member 102.

[0076]

[0084] In some embodiments, controlled heating and / or local heating may be performed such that different sections along the length of the elongate member 102 have different phase transition temperatures. This can be done, for example, by laser heating. In particular, a first set of heat treatment conditions can be applied to a first set of sections (e.g., sections 302, 412, etc.) along the length of the elongate member 102 such that their transition temperatures are higher than body temperature (37 °C). Thus, these sections will retain the martensite phase when the device is deployed at the treatment site. That is, since there is no phase transition from martensite to austenite, these can be considered irreversible martensite sections. In contrast, a second set of heat treatment conditions can be applied to a second set of sections (e.g., sections 300, 304, 410, 414, etc.) such that their transition temperatures are lower than body temperature (37 °C). These sections will undergo a phase transition from martensite to austenite when the occlusion device 100 is deployed at the treatment site. These are considered reversible martensite sections. In general, thermally induced martensite forms as twinned martensite, and the twinned martensite structure can change to a non-twinned martensite structure as the material reaches the transition temperature and deforms in the martensite state.

[0077]

[0085] In other embodiments, deformation strain control may be applied to different sections along the length of the elongate member 102. In particular, a first strain condition is applied to a first set of sections (e.g., sections 302, 412, etc.) such that the strain exceeds the recoverable limit of the martensite phase, thereby preventing the martensite phase from transitioning to the austenite phase when the plug device is deployed at the treatment site. Since these sections always retain the martensite phase, they are considered irreversible martensite sections. On the other hand, a second strain condition is applied to a second set of sections (e.g., sections 300, 304, 410, 414, etc.) such that the strain level is within their recoverable limit, thereby allowing the martensite phase to transition to the austenite phase when the plug device 100 is deployed at the treatment site. Thus, these sections are considered reversible martensite sections.

[0078]

[0086] In other embodiments, while chemically and / or heat treating other portions of the elongate member 102, a portion of the elongate member 102 may be covered with a shielding material. This allows different portions of the elongate member 102 to be formed with different mechanical properties. For example, this technique can be used to create irreversible martensite sections and reversible martensite sections along the length of the elongate member 102.

[0079]

[0087] In further embodiments, a combination of the above techniques may be used to create irreversible martensite sections and reversible martensite sections along the length of the elongate member 102.

[0080]

[0088] In other embodiments, other techniques for shaping the elongate member may be used to form the plug device 100.

[0081]

[0089] The elongated member 102 has a deployed shape (e.g., the examples shown in FIGS. 4 and 6), and after being formed to have both irreversible martensite sections (e.g., sections 302, 412, etc.) and reversible martensite sections (e.g., sections 300, 304, 410, 414, etc.) along the length of the elongated member 102, the elongated member 102 can be further processed to form a delivery shape (e.g., as in the examples shown in FIGS. 3 and 5). In some embodiments, this can be achieved using a thermal cycle. For example, the elongated member 102 (already formed to have a deployed shape) may be heated and cooled repeatedly while being placed in the desired delivery shape to be formed. In one approach, the elongated member 102 may be tensioned in a linear profile while being repeatedly heated and cooled. In some embodiments, the heating can heat the elongated member 102 to a temperature higher than 80°C, more preferably higher than 90°C (e.g., 100°C), or more preferably higher than 100°C. Also, in some embodiments, the cooling may cool the elongated member 102 to a temperature less than 10°C, more preferably less than 0°C, or more preferably less than -10°C. Using this technique, the plug device 100 can be created such that it has a first shape (delivery shape) when at room temperature and a second shape (deployed shape) when deployed in a patient's body and at body temperature. FIG. 7 is a stress-strain graph showing the effect of the thermal cycle in particular. As can be seen from the graph, when the elongated member 102 is heated and cooled, thermal stress is applied to the elongated member 102, thereby shifting the stress-strain curve of the elongated member 102. Repeating the heating and cooling in additional cycles applies additional thermal stress to the elongated member 102, thereby further shifting the stress-strain curve.

[0082]

[0090] Note that the transition temperature at which the plug device 100 changes from the delivery shape to the deployed shape can be selectively configured using the material composition and / or the manufacturing process. For example, the austenitizing finishing temperature can be selected for a given material's manufacturing process such that the finished product has the desired transition temperature.

[0083]

[0091] Figures 8A - 8B illustrate a method of using the medical device 10 of FIG. 1 to treat an aneurysm 700. When using the medical device 10, first, a catheter 20 is inserted into a patient's blood vessel 702 through an incision. Next, the catheter 20 is advanced distally until the distal end 22 of the catheter 20 reaches the aneurysm 700.

[0084]

[0092] In some embodiments, the catheter 20 can be steerable. For example, the catheter 20 can include one or more steering wires configured to steer the distal end 22 of the catheter 20 in one or more directions. In other embodiments, the catheter 20 may not be steerable. Instead, a guide wire can first be used to access the target site. Next, the catheter 20 can be placed on the guide wire and advanced distally using the guide wire. In this case, the catheter 20 can include a separate channel for accommodating the guide wire.

[0085]

[0093] After the distal end 22 of the catheter 20 is desirably positioned, the shaft 30 (shown in FIG. 1) is then advanced to push the plug device 100 distally so that the first distal portion of the plug device 100 exits the catheter 20 (FIG. 8A). The plug device 100 has a linear profile when it is at room temperature inside the catheter 20. This linear profile is due to the plug device 100 being at room temperature and not due to mechanical correction by the catheter 20. Thus, the plug device 100 can be easily advanced distally. Due to this feature, a longer plug device 100 can also be delivered if desired. As shown, the first portion of the elongate member 102 changes to form the first portion of the three-dimensional structure 112 from its relatively straight shape in response to body temperature when the first portion of the elongate member 102 becomes unconstrained outside the catheter 20. In particular, the reversible martensite compartments (e.g., compartments 300, 304, 410, 414, etc.) along the elongate member 102 undergo a phase change to become austenite compartments in response to body temperature. These austenite compartments have a curved profile to provide a delivery shape to the deployed portion of the elongate member 102. The irreversible martensite compartments (e.g., compartments 302, 412, etc.) along the elongate member 102 remain in the martensite phase. These irreversible martensite compartments are softer than the reversible martensite compartments and thus are more easily bent in response to force. Thus, when the first portion of the three-dimensional structure 112 is delivered to the aneurysm, the loops of the three-dimensional structure 112 are pushed towards the wall of the aneurysm, thereby applying a force to the irreversible martensite compartments. These compartments bend in response to the force, thereby enabling the delivered first portion of the three-dimensional structure 112 to better conform to the shape of the aneurysm 700.

[0086]

[0094] In the illustrated example, the first portion of the three-dimensional structure 112 has a shape corresponding to the inner wall of the aneurysm. The first portion of the three-dimensional structure 112, schematically represented by the dashed line in FIG. 8A, provides a frame that defines a cavity 118 for accommodating a subsequent portion of the delivery embolization device 100. As shown, the first portion of the three-dimensional structure 112 also provides a scaffold spanning the neck portion 704 of the aneurysm 700, which helps to accommodate a subsequent portion of the elongate member 102 of the embolization device 100 delivered to the cavity 118.

[0087]

[0095] Next, the shaft 30 can be further advanced to extrude a subsequent portion of the embolization device 100 from the catheter 20 (FIG. 8B). As shown, the subsequent portion forms a second portion of the three-dimensional structure 112 once this subsequent portion is in an unconstrained state outside the catheter 20. The second portion of the three-dimensional structure 112 has a shape that can fill at least a portion of the space within the cavity 118 defined by the first portion of the three-dimensional structure 112. As shown, the scaffold spanning the neck portion 704 of the aneurysm provided by the first portion of the three-dimensional structure 112 prevents the second portion of the three-dimensional structure 112 from escaping or falling out of the cavity 118 of the first portion of the three-dimensional structure 112 and into the aneurysm.

[0088]

[0096] As described similarly for the first portion of the three-dimensional structure 112, for the second portion of the three-dimensional structure 112, the reversible martensite compartments along the elongate member 102 undergo a phase change to become austenite compartments in response to body temperature. These austenite compartments have a curved profile to provide a delivery shape to the deployed portion of the elongate member 102. On the other hand, the irreversible martensite compartments along the elongate member 102 remain in the martensite phase. These irreversible martensite compartments are softer than the reversible martensite compartments and thus are more likely to bend in response to a force. Accordingly, when the second portion of the three-dimensional structure 112 is delivered into an aneurysm, the loop of the three-dimensional structure 112 is pushed toward the wall of the aneurysm (or toward the first portion of the three-dimensional structure 112), applying a force to the irreversible martensite compartments. These compartments bend in response to the force, thereby enabling the second portion of the delivered three-dimensional structure 112 to better conform to the shape of the cavity to be filled.

[0089]

[0097] In some embodiments, the distal end of the shaft 30 abuts the proximal end of the elongate member 102 and is not mechanically attached to the proximal end of the elongate member 102. In such a case, as soon as the proximal end of the elongate member 102 is pushed out of the catheter 20, the elongate member 102 becomes detached from the remainder of the medical device 10. In other embodiments, the distal end of the shaft 30 can be mechanically connected to the proximal end of the elongate member 102, such as via a mechanical connector operable to disconnect the proximal end of the elongate member 102 from the shaft 30. In further embodiments, the distal end of the shaft 30 may be mechanically connected to the proximal end of the elongate member 102 via a degradable link, such as a link that can disintegrate in response to the application of an electric current. Mechanical connectors and degradable links are well known in the art and thus will not be described in further detail.

[0090]

[0098] As shown in the above embodiments, this plugging device 100 has soft individual irreversible martensite compartments that give the plugging device 100 a certain degree of flexibility, whereby the plugging device 100 bends easily in response to force, which is advantageous. Specific individual parts (irreversible martensite compartments) of the plugging device 100 can be bent more easily, while most other parts of the plugging device 100 (i.e., reversible martensite compartments) remain relatively rigid compared to the irreversible martensite compartments, whereby the shape of most of the plugging device 100 can be maintained within the body cavity. Further, it is also an advantage that the delivery shape of the plugging device 100 within the catheter 20 is relatively straight compared to the deployed shape. Thereby, the plugging device 100 can be easily advanced distally relative to the catheter 20 without using a large axial pressing force, and the risk of the plugging device 100 buckling within the catheter 20 can be reduced.

[0091]

[0099] In some embodiments, a plurality of plugging devices 100 may be provided with different lengths. In such a case, before one of the plugging devices 100 is selected to treat an aneurysm, a physician may measure the size of the aneurysm to be treated. For example, the physician can perform the measurement using one or more images of the aneurysm and determine the size of the aneurysm. The size can be the cross-sectional dimension of the aneurysm, the cross-sectional area of the aneurysm, the volume of the aneurysm, etc. After determining the size of the aneurysm, one of the plugging devices 100 can be selected based on the size of the aneurysm. For example, a longer plugging device 100 can be selected to occlude a large aneurysm.

[0092]

[0100] Figure 9 shows a method 800 for occluding a body cavity. This method 800 is performed by a plug device having an elongate member, the elongate member having a first section, a second section, and a third section, the second section being between the first section and the third section. Method 800 includes the step (item 802) in which, in response to body temperature, the first section of the elongate member undergoes a first shape change, the step (item 804) in which, in response to a force, the second section of the elongate member undergoes a second shape change, and the step (item 806) in which, in response to body temperature, the third section of the elongate member undergoes a third shape change.

[0093]

[0101] In some embodiments, the plug device of method 800 can be plug device 100 described herein.

[0094]

[0102] Optionally, in this method, the first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature, and the second section is martensite when the second section is at room temperature and also martensite when the second section is at body temperature.

[0095]

[0103] Optionally, in this method, in response to body temperature, the first section forms a first portion of a loop and the third section forms a second portion of the loop.

[0096]

[0104] Optionally, in this method, in response to body temperature, the first section forms a first loop and the third section forms a second loop.

[0097]

[0105] Optionally, in this method, the first section has a first length, the second section has a second length, and the third section has a third length. Here, the second length of the second section is shorter than the first length of the first section and also shorter than the third length of the third section.

[0098]

[0106] Optionally, in this method, the second length of the second section between the first section and the third section is less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

[0099]

[0107] Optionally, in this method, the elongate member has a distal end and a proximal end opposite the distal end, and the plug device further includes a fourth section including the proximal end. This fourth section is martensite when at room temperature and is also martensite when the fourth section is at body temperature.

[0100]

[0108] Optionally, in this method, the three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section are part of one of the loops.

[0101]

[0109] Optionally, in this method, the elongate member further includes a fourth section, a fifth section, and a sixth section that are part of another one of the loops. Here, the fifth section is between the fourth section and the sixth section. Here, the fourth section and the sixth section are martensite when the fourth section and the sixth section are at room temperature and are austenite when the fourth section and the sixth section are at body temperature. Here, the fifth section is martensite when the fifth section is at room temperature and is also martensite when the fifth section is at body temperature.

[0102]

[0110] The following items are exemplary features of the embodiments described herein. Each item can itself be an embodiment or part of an embodiment. In one embodiment, one or more of the items described below may be combined with other items.

[0103]

[0111] Item 1: In a plug device for placement within a body cavity, comprising an elongate member having a linear configuration at room temperature, the elongate member being configured to form a first three-dimensional structure in response to body temperature, the elongate member including a first section, a second section, and a third section, the second section being located between the first section and the third section, the first section and the third section being configured to change their respective shapes in response to body temperature, and the second section located between the first section and the third section having a shape independent of body temperature.

[0104]

[0112] Item 2: The first section is configured to form a first portion of a loop, and the third section is configured to form a second portion of the loop in response to body temperature.

[0105]

[0113] Item 3: In response to body temperature, the first section is configured to form a first loop, and the third section is configured to form a second loop.

[0106]

[0114] Item 4: The first section has a first length, the second section has a second length, the third section has a third length, the second length of the second section is shorter than the first length of the first section, and is also shorter than the third length of the third section.

[0107]

[0115] Item 5: The second length of the second section between the first section and the third section is less than 50% of the first length of the first section, and is also less than 50% of the third length of the third section.

[0108]

[0116] Item 6: The elongate member has a distal end and a proximal end opposite the distal end, and the plug device further includes a fourth section including the proximal end, the fourth section being martensite when the fourth section is at room temperature and also being martensite when the fourth section is at body temperature.

[0109]

[0117] Item 7: The first section is martensite when the first section is at room temperature and is austenitic when the first section is at body temperature.

[0110]

[0118] Item 8: When the second section is at room temperature, the second section is martensite, and when the second section is at body temperature, it is also martensite.

[0111]

[0119] Item 9: The three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section are part of one of the loops.

[0112]

[0120] Item 10: The elongated member further includes a fourth section, a fifth section, and a sixth section that are part of another one of the loops. The fifth section is between the fourth section and the sixth section. The fourth section and the sixth section are configured to change their respective shapes in response to body temperature, and the fifth section located between the fourth section and the sixth section has a shape that does not depend on body temperature.

[0113]

[0121] Item 11: In a plug device for placement in a body cavity, it comprises an elongated member having a linear configuration at room temperature. The elongated member is configured to form a first three-dimensional structure in response to body temperature. The elongated member includes a first section, a second section, and a third section. The second section is located between the first section and the third section. The first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature. The second section is martensite when the second section is at room temperature and also martensite when the second section is at body temperature.

[0114]

[0122] Item 12: In response to body temperature, the first section is configured to form a first part of the loop, and the third section is configured to form a second part of the loop.

[0115]

[0123] Item 13: In response to body temperature, the first section is configured to form a first loop, and the third section is configured to form a second loop.

[0116]

[0124] Item 14: The first section has a first length, the second section has a second length, the third section has a third length, and the second length of the second section is shorter than the first length of the first section and also shorter than the third length of the third section.

[0117]

[0125] Item 15: The second length of the second section between the first section and the third section is less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

[0118]

[0126] Item 16: The elongated member has a distal end and a proximal end opposite the distal end, and the plug device further includes a fourth section including the proximal end, and the fourth section is martensite when at room temperature and is also martensite when the fourth section is at body temperature.

[0119]

[0127] Item 17: The three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section are part of one of the plurality of loops.

[0120]

[0128] Item 18: The elongated member further includes a fourth section, a fifth section, and a sixth section that are part of another one of the plurality of loops, the fifth section is between the fourth section and the sixth section, the fourth section and the sixth section are martensite when the fourth section and the sixth section are at room temperature and are austenite when the fourth section and the sixth section are at body temperature, and the fifth section is martensite when the fifth section is at room temperature and is also martensite when the fifth section is at body temperature.

[0121]

[0129] Item 19: A method of occluding a body cavity performed by a plug device having an elongated member, the elongated member including a first section, a second section, and a third section, the second section being between the first section and the third section, the method including the steps of undergoing a first shape change by the first section of the elongated member in response to body temperature, undergoing a second shape change by the second section of the elongated member in response to a force, and undergoing a third shape change by the third section of the elongated member in response to body temperature.

[0122]

[0130] Item 20: The first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature. The second section is martensite when the second section is at room temperature and also martensite when the second section is at body temperature.

[0123]

[0131] Item 21: In response to body temperature, the first section forms the first part of the loop and the third section forms the second part of the loop.

[0124]

[0132] Item 22: In response to body temperature, the first section forms the first loop and the third section forms the second loop.

[0125]

[0133] Item 23: The first section has a first length, the second section has a second length, the third section has a third length, the second length of the second section is shorter than the first length of the first section, and also shorter than the third length of the third section.

[0126]

[0134] Item 24: The second length of the second section between the first section and the third section is less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

[0127]

[0135] Item 25: The elongate member has a distal end and a proximal end opposite the distal end. The plug device further includes a fourth section including the proximal end. The fourth section is martensite when at room temperature and also martensite when the fourth section is at body temperature.

[0128]

[0136] Item 26: The three-dimensional structure includes a plurality of loops. The first section, the second section, and the third section are part of one of the plurality of loops.

[0129]

[0137] Item 27: The elongated member further includes a fourth section, a fifth section, and a sixth section that are part of another loop among the plurality of loops. The fifth section is between the fourth section and the sixth section. The fourth section and the sixth section are martensite when the fourth section and the sixth section are at room temperature, and are austenite when the fourth section and the sixth section are at body temperature. The fifth section is martensite when the fifth section is at room temperature and is also martensite when the fifth section is at body temperature.

Claims

1. In a plug device for placement within a body cavity, comprising an elongate member having a linear configuration at room temperature, the elongate member being configured to form a first three-dimensional structure in response to body temperature, the elongate member includes a first section, a second section, and a third section, the second section being located between the first section and the third section, the first section and the third section are configured to change their respective shapes in response to body temperature, the second section located between the first section and the third section has a shape independent of body temperature, characterized by a plug device.

2. In response to body temperature, the first section is configured to form a first portion of a loop, and the third section is configured to form a second portion of the loop, the plug device according to claim 1.

3. In response to body temperature respectively, the first section is configured to form a first loop, and the third section is configured to form a second loop, the plug device according to claim 1.

4. The first section has a first length, the second section has a second length, the third section has a third length, the second length of the second section is shorter than the first length of the first section, and further shorter than the third length of the third section, the plug device according to claim 1.

5. The second length of the second section between the first section and the third section is less than 50% of the first length of the first section and less than 50% of the third length of the third section, the plug device according to claim 4.

6. The elongate member has a distal end and a proximal end opposite the distal end, and the plug device further includes a fourth section including the proximal end, the fourth section being martensite at room temperature, and the fourth section being martensite also at body temperature, the plug device according to any one of claims 1 to 5.

7. The first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature, the plug device according to any one of claims 1 to 6.

8. The second section is martensite when the second section is at room temperature and martensite when the second section is at body temperature, the plug device according to any one of claims 1 to 7.

9. The three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section include respective portions of one of the plurality of loops. The plug device according to any one of claims 1 to 8.

10. The elongated member further includes a fourth section, a fifth section, and a sixth section that include respective portions of another one of the plurality of loops. The fifth section is between the fourth section and the sixth section. The fourth section and the sixth section are configured to change their respective shapes according to body temperature. The plug device according to claim 9, wherein the fifth section located between the fourth section and the sixth section has a shape independent of body temperature.

11. In a plug device for placement in a body cavity. Comprising an elongated member having a linear configuration at room temperature, the elongated member being configured to form a first three-dimensional structure in response to body temperature. The elongated member includes a first section, a second section, and a third section, and the second section is located between the first section and the third section. The first section is martensite when the first section is at room temperature and austenite when the first section is at body temperature. The plug device, wherein the second section is martensite when the second section is at room temperature and also martensite when the second section is at body temperature.

12. The plug device according to claim 11, wherein in response to body temperature, the first section is configured to form a first portion of a loop and the third section is configured to form a second portion of the loop.

13. The plug device according to claim 11, wherein in response to body temperature, the first section is configured to form a first loop and the third section is configured to form a second loop.

14. The first section has a first length, the second section has a second length, and the third section has a third length. The plug device according to claim 11, wherein the second length of the second section is shorter than the first length of the first section and also shorter than the third length of the third section.

15. The plug device according to claim 14, wherein the second length of the second section between the first section and the third section is less than 50% of the first length of the first section and also less than 50% of the third length of the third section.

16. The elongate member has a distal end and a proximal end opposite the distal end, the plug device further includes a fourth section including the proximal end, the fourth section is martensite at room temperature and the fourth section is also martensite at body temperature, the plug device according to any one of claims 11 to 15.

17. the three-dimensional structure includes a plurality of loops, and the first section, the second section, and the third section include respective portions of one of the plurality of loops, the plug device according to any one of claims 11 to 16.

18. the elongate member further includes a fourth section, a fifth section, and a sixth section including respective portions of another one of the loops, the fifth section is between the fourth section and the sixth section, the fourth section and the sixth section are martensite when the fourth section and the sixth section are at room temperature and austenite when the fourth section and the sixth section are at body temperature, the fifth section is martensite when the fifth section is at room temperature and is also austenite when the fifth section is at body temperature, the plug device according to claim 17.

Images