Novel suture-free aortic valve

Abstract

The invention relates to the technical field of medical instruments, in particular to a novel suture-free aortic valve. The problem that the aortic valve is prone to perivalvular leakage under the action of hypertension is solved. Comprising an aortic valve; the pericardial sheet is installed on a valve ring of the aortic valve, and the valve ring of the aortic valve is located in the middle of the pericardial sheet, so that the pericardial sheet forms skirt edges on the two sides of the valve ring on the aortic valve and is used for blocking blood flow; the valve support is installed on the pericardial sheet, and the valve support deforms to be used for being tightly attached to the aortic wall and providing supporting force for the pericardial sheet and the aortic valve. The pericardial sheet is connected with the valve ring of the aortic valve to form two skirt edges, so that the sealing performance between the pericardial sheet and the aortic valve is improved, the working stability of the aortic valve is improved, and perivalvular leakage can be better prevented.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a novel suture-free aortic valve. Background Art

[0002] The sutureless aortic valve is an advanced medical device used to treat aortic valve disease. The leaflets of the sutureless aortic valve are usually made of biological tissue (such as pig valves or bovine pericardium). The leaflets are biological tissues with the advantage of good compatibility with human tissues. However, during the use of the existing aortic valve made of biological tissue, if the patient has symptoms of hypertension, hypertension will increase the heart load, causing the valve to be under greater pressure, making it easy for blood to flow between the valve and the aortic wall, causing paravalvular leakage of the aortic valve, thereby causing a series of hazards to the patient's heart function and overall health. Summary of the invention

[0003] In order to overcome the problem that the existing biological tissue-made aortic valve is prone to paravalvular leakage under the action of hypertension, which endangers the overall health of patients, the present invention provides a new type of suture-free aortic valve.

[0004] The technical solution is: a new type of suture-free aortic valve, including: Aortic valve; The pericardium sheet is installed on the valve ring of the aortic valve, and the valve ring of the aortic valve is located in the middle of the pericardium sheet, so that the pericardium sheet forms skirts on both sides of the valve ring of the aortic valve to block blood flow; A valve support is installed on the pericardium sheet. The valve support is deformed to fit closely to the aortic wall, thereby providing support for the pericardium sheet and the aortic valve.

[0005] More preferably, the pericardial sheet is composed of an annular protrusion and two symmetrically distributed annular sleeves; The annular protrusion is connected to the valve ring of the aortic valve, and is U-shaped in a cross-sectional view in the direction of the centerline of the pericardial sheet, and wraps the valve ring of the aortic valve. The annular protrusion is sutured with first coils distributed equidistantly in the circumferential direction, and the first coils penetrate the aortic valve; The two annular sleeves are located at two ends of the annular protrusion, and the aortic valve is located in the middle of the annular sleeves.

[0006] More preferably, the annular sleeve is trumpet-shaped, and the diameter of the annular sleeve gradually decreases from both ends to the middle of the pericardial sheet.

[0007] More preferably, the valve support is composed of vertical segments equidistantly distributed circumferentially, wavy segments equidistantly distributed circumferentially, a first circular segment and a second circular segment; The vertical segment is located between the aortic valve and the pericardial plate; The wave segments are fixedly connected to the adjacent vertical segments, and the wave segments distributed evenly and the vertical segments distributed evenly correspond to each other one by one; The first annular segment is fixedly connected to the wave segments which are equidistantly distributed in the circumferential direction and arranged in a circumferential wave shape; The second circular ring segment is fixedly connected to the first circular ring segment and is arranged in a circumferential wave shape.

[0008] More preferably, the vertical section includes: An arc segment is located on the vertical segment, the arc segment is used to clamp the valve ring of the aortic valve, and the annular protrusion wraps the arc segment.

[0009] More preferably, the wavelength of the waves on the first circular ring segment is greater than the wavelength of the waves on the second circular ring segment, and the ratio of the two wavelengths is an integer.

[0010] More preferably, the first circular ring segment and the second circular ring segment form an annular structure, and the diameters at both ends of the annular structure are smaller than the diameter in the middle.

[0011] More preferably, the pericardium sheet further comprises: A plurality of groups of second coils equidistantly distributed in the circumferential direction, the number of the groups being the same as the number of leaflets of the aortic valve, the plurality of groups of the second coils being respectively sutured to the connection between two adjacent leaflets of the aortic valve, and the vertical section close to the two adjacent leaflets of the aortic valve being sutured to between the two leaflets, and the second coils being cross coils; A plurality of groups of third coils equidistantly distributed in the circumferential direction are respectively sutured to the connection between two adjacent leaflets and the adjacent annular sleeves on the aortic valve, and the third coils wrap the adjacent vertical segments.

[0012] More preferably, it also includes a circumferentially distributed support frame: The support frames distributed circumferentially are respectively fixed to two adjacent vertical segments, the support frames are made of elastic material, and are used to squeeze the adjacent annular sleeves and expand them outwards; The support frame consists of a first arc segment, two second arc segments and two third arc segments, the first arc segment is spiral, the two ends of the first arc segment are at different distances from the center line of the pericardium sheet, and the two second arc segments have different lengths.

[0013] More preferably, the arc segment, the wave segment, the first circular ring segment, the second circular ring segment and the first arc segment are all memory metals, which are used to change their shapes at different temperatures.

[0014] The beneficial effects of the present invention are as follows: the present invention connects the middle part of the pericardial sheet with the valve ring of the aortic valve, so that the pericardial sheet forms skirts on both sides of the valve ring of the aortic valve, thereby increasing the contact area between the aortic valve and the aortic wall, thereby enhancing the stability of the aortic valve in the aortic wall, and the two skirts formed can better prevent paravalvular leakage; by limiting the wavelength of the waves on the first circular ring segment to be greater than the wavelength of the waves on the second circular ring segment, excessive expansion and contraction changes in the deforming valve stent in the vertical direction are avoided, and at the same time, the valve stent is convenient to be close to the designated position in the aortic wall during the deformation process, thereby improving the installation accuracy of the device; by utilizing the elastic support of the support frame, the support frame squeezes the pericardial sheet to be close to the aortic wall, thereby further maintaining the sealing between the device and the aortic wall, thereby avoiding the occurrence of paravalvular leakage, and at the same time, the elastic support of the support frame prevents the pericardial sheet from bending during the contraction of the aortic wall, thereby further improving the working stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the three-dimensional structure of the valve stent and the support frame of the present invention; Figure 3 It is a cross-sectional view of the pericardium sheet of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure of the vertical section and the wave section of the present invention; Figure 5 It is a front view of the first circular ring segment and the second circular ring segment of the present invention; Figure 6 It is a schematic diagram of the three-dimensional structure of the pericardium sheet and the support frame of the present invention; Figure 7 It is a schematic diagram of the three-dimensional structure at the second arc segment and the third arc segment of the present invention.

[0016] The markings of the components in the accompanying drawings are as follows: 1. aortic valve, 2. pericardial plate, 201. annular protrusion, 202. annular sleeve, 3. first coil, 301. second coil, 302. third coil, 4. valve support, 401. vertical segment, 4011. arc segment, 402. wavy segment, 403. first circular segment, 404. second circular segment, 5. support frame, 501. first arc segment, 502. second arc segment, 503. third arc segment. DETAILED DESCRIPTION

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0018] Existing sutureless active valves are often installed at the aortic valve position of the heart using an elastic stent, wherein the sutureless active valve utilizes the elastic force of the elastic stent to adhere tightly to the aortic wall. When patients with hypertension symptoms replace the sutureless active valve, the hypertension symptoms will increase the heart load, causing the valve to be subjected to greater pressure. Under the action of high pressure, blood is likely to flow between the valve and the aortic wall, endangering the overall health of the patient.

[0019] Embodiment 1: A novel suture-free aortic valve, such as Figure 1 and Figure 2 As shown, it includes: an aortic valve 1, which is usually made of a pig valve or a bovine pericardial valve, and the material can be specified according to the patient's needs; a pericardial sheet 2, which is installed on the valve ring of the aortic valve 1. The pericardial sheet 2 increases the contact area between the aortic valve 1 and the aortic wall after the aortic valve 1 is installed, thereby improving the stability of the aortic valve 1 after installation, and the valve ring of the aortic valve 1 is located in the middle of the pericardial sheet 2, so that the pericardial sheet 2 forms skirts on the upper and lower sides of the valve ring of the aortic valve 1. After the aortic valve 1 is installed, the blood around the aortic valve 1 will squeeze the inner side of the pericardial sheet 2, thereby enhancing the sealing between the aortic valve 1 and the aortic wall, and better preventing paravalvular leakage; a valve stent 4, which is installed on the pericardial sheet 2. The valve stent 4 can undergo elastic deformation. When the valve stent 4 is a balloon-expandable stent , a special tool is often used to squeeze the valve stent 4 to shrink circumferentially, and the aortic valve 1 is deformed at the same time, and then it is installed using an existing special delivery system (shown in the figure). After the aortic valve 1 reaches the specified position, the balloon is controlled to expand and pressurize the valve stent 4 and the aortic valve 1 to expand and deform. When the valve stent 4 is a self-expanding stent, the valve stent 4 is often placed in cold water to soften and shrink it, and then the above operation is repeated to install the aortic valve 1 to the specified position. During the above process, the deformation of the valve stent 4 squeezes the pericardial sheet 2, so that the pericardial sheet 2 is close to the aortic wall, further improving the stability of the aortic valve 1 after installation. At the same time, the valve stent 4 supports the leaflets of the aortic valve 1 to prevent abnormal deformation under high pressure, that is, to improve the working stability of the aortic valve 1 during use.

[0020] like Figure 2 and Figure 3As shown, the pericardial plate 2 is composed of an annular protrusion 201 and two annular sleeves 202 symmetrically distributed up and down; the annular protrusion 201 is connected to the valve ring of the aortic valve 1. The setting of the annular protrusion 201 allows the aortic valve 1 to form a circumferential support, which helps the aortic valve 1 to remain three-dimensional. At the same time, since the annular protrusion 201 is relatively thick, the annular protrusion 201 is prevented from bending in the circumferential direction to a certain extent, so that the valve ring of the aortic valve 1 remains regular. The cross-sectional view of the annular protrusion 201 in the center line direction of the pericardial plate 2 is U-shaped, and it wraps the valve ring of the aortic valve 1, which is used to improve the sealing between the aortic valve 1 and the pericardial plate 2, and avoid paravalvular leakage of the aortic valve 1 during use. The annular protrusion 201 is sutured with first coils 3 equidistantly distributed in the circumferential direction. The first coil 3 penetrates the aortic valve 1, and the seams of the first coil 3 The combination further improves the sealing between the aortic valve 1 and the pericardium piece 2. At the same time, the first coil 3 forms multiple protrusions on the outer side of the annular protrusion 201. The annular protrusion 201 squeezes the aortic wall to form an irregular squeezing surface, thereby improving the stability of the aortic valve 1 in the aortic wall after installation; two annular sleeves 202 are located at both ends of the annular protrusion 201, and the aortic valve 1 is located in the middle of the annular sleeve 202. The annular sleeve 202 is trumpet-shaped, and the diameter of the annular sleeve 202 gradually decreases from both ends to the middle of the pericardium piece 2. The trumpet-shaped setting of the annular sleeve 202 is used to guide blood to impact its inner side, thereby assisting the annular sleeve 202 to fit with the aortic wall, improving the sealing between the aortic valve 1 and the aortic wall, avoiding paravalvular leakage of the aortic valve 1, and ensuring that the position of the aortic valve 1 in the heart remains stable.

[0021] like Figure 2 , Figure 4 and Figure 5As shown, the valve support 4 is composed of vertical segments 401 equidistantly distributed in the circumferential direction, wavy segments 402 equidistantly distributed in the circumferential direction, a first annular segment 403 and a second annular segment 404. There are six vertical segments 401 and six wavy segments 402 in the figure; the vertical segment 401 is located between the aortic valve 1 and the pericardial piece 2, and a fold is provided at the lower part of the vertical segment 401 to squeeze the lower part of the pericardial piece 2 close to the aortic wall; the wavy segment 402 is fixedly connected to the upper end of the adjacent vertical segment 401, and the equidistantly distributed wavy segments 402 correspond to the equidistantly distributed vertical segments 401 one by one; the first annular segment 403 is fixedly connected to the aortic valve 1 and the pericardial piece 2. The wave segments 402 are equidistantly distributed in the circumferential direction, and are arranged in a circumferential wave pattern; the second annular segment 404 is fixedly connected to the first annular segment 403 and is arranged in a circumferential wave pattern. The wavelength of the wave on the first annular segment 403 is greater than the wavelength of the wave on the second annular segment 404, and the ratio of the two wavelengths is an integer (the ratio shown in the figure is 2). The structural design of the first annular segment 403 and the second annular segment 404 in the accompanying drawings makes the two peaks of the second annular segment 404 corresponding to the trough on the first annular segment 403 gradually move away from each other during the expansion deformation process. In this process, the distance between the corresponding two peaks on the second annular segment 404 is The trough moves upward to avoid excessive expansion and contraction of the upper end of the second circular segment 404 and the lower end of the first circular segment 403 in the vertical direction, so that the two can be closely attached to the designated position of the aortic wall during the deformation process. At the same time, the wave design of the first circular segment 403 and the second circular segment 404 increases the contact area between the device and the aortic arm, further improving the working stability of the device. The design of the wave segment 402 enables the length between the two ends of the wave segment 402 to adjust the distance between the first circular segment 403 and the aortic valve 1 according to the actual length required by the patient, so that the first circular segment 403 is fixed. The device is fixed at a designated position in the patient's aortic wall to improve the applicability of the device. At the same time, the wave segment 402 is closely attached to the aortic wall due to its bending arc, further improving the stability of the device in the aortic wall. The first circular segment 403 and the second circular segment 404 form an annular structure, and the diameters of both ends of the annular structure are smaller than the middle diameter, that is, the middle part of the annular structure protrudes to support the aortic wall, avoiding the lower end of the first circular segment 403 and the upper end of the second circular segment 404 from being inserted into the aortic wall, thereby reducing the stimulation of the lower end of the first circular segment 403 and the upper end of the second circular segment 404 to the aortic wall.

[0022] like Figure 4 and Figure 5As shown, the vertical section 401 includes: an arc section 4011, located at the lower part of the vertical section 401, the arc section 4011 is used to clamp the valve ring of the aortic valve 1, so that the aortic valve 1 maintains circumferential expansion, which is convenient for the subsequent suturing and installation of the pericardial sheet 2 on the valve ring of the aortic valve 1, reducing the processing difficulty of the device, and the annular protrusion 201 wraps the arc section 4011. The setting of the annular protrusion 201 makes the valve ring of the aortic valve 1 thicker, thereby enhancing the valve ring of the aortic valve 1 to remain relatively regular in the circumferential direction.

[0023] Specific working principle: according to the patient's needs, a balloon-expandable valve stent 4 or a self-expandable valve stent 4 is selected, and then the valve stent 4 and the aortic valve 1 are contracted, and then a special delivery system is used to deliver the contracted device to a designated area in the heart, and then the valve stent 4 and the aortic valve 1 in the device are expanded and deformed together in a corresponding manner, and the valve stent 4 expands and fits tightly against the aortic wall. The valve stent 4 deforms and squeezes the pericardial piece 2 at the same time, so that the pericardial piece 2 fits tightly against the aortic wall, and then the special delivery system is taken out, and the working status of the aortic valve 1 is observed using imaging equipment, and then the remaining surgical treatments are performed to complete the replacement of the aortic valve 1.

[0024] Embodiment 2: Based on embodiment 1, Figure 1 and Figure 3 As shown, the pericardium sheet 2 also includes: a plurality of groups of second coils 301 equidistantly distributed in the circumferential direction, the number of groups being the same as the number of leaflets of the aortic valve 1 (three groups are shown in the figure), each group of second coils 301 includes two vertically distributed ones, the number of which is indicated in the figure, and in actual situations, a specified number of sutures can be performed according to the length of the leaflets of the aortic valve 1, and the plurality of groups of second coils 301 are respectively sutured at the connection between two adjacent leaflets on the aortic valve 1, and a vertical segment 401 close to two adjacent leaflets on the aortic valve 1 is sutured between the two leaflets, and the corresponding vertical segment 401 is sutured between the two leaflets in the aortic valve 1, so as to further support the leaflets of the aortic valve 1 and improve its stability during use. The working stability during the operation, the second coil 301 is a cross coil, and the cross suture improves the sealing between the aortic valve 1 and the vertical segment 401, so that the aortic valve 1 remains stable during the operation; multiple groups of third coils 302 are circumferentially equidistantly distributed, each group of third coils 302 includes three vertically distributed, and the number is indicated in the figure. In actual circumstances, according to the length of the upper annular sleeve 202, a specified number of sutures can be performed. The three groups of third coils 302 are respectively sutured at the connection between two adjacent leaflets on the aortic valve 1 and the adjacent annular sleeves 202, and the third coils 302 wrap the adjacent vertical segments 401. The suture principle improves the stability of the aortic valve 1 during the operation.

[0025] In the above solution, the stability of the aortic valve 1 during operation is further improved by deeply suturing and connecting the aortic valve 1 with the corresponding annular sleeve 202 and the corresponding vertical segment 401 .

[0026] Embodiment 3: Based on embodiment 2, Figure 2 , Figure 6 and Figure 7 As shown, it also includes a circumferentially distributed support frame 5: the circumferentially distributed support frame 5 is respectively fixed to two adjacent vertical segments 401. The number of support frames 5 shown in the figure is six. When the shape of the aortic valve 1 and the shape of the valve support 4 change, the number thereof changes accordingly. The support frame 5 is in the shape of a "J". The support frame 5 is made of elastic material. The support frame 5 is used to squeeze the adjacent annular sleeve 202 and expand it outward, so as to assist the annular sleeve 202 to fit closely to the inner wall of the aorta to prevent it from turning inward. The support frame 5 is composed of a first arc segment 501, two second arc segments 502 and two third arc segments 503. The first arc segment 501 is spiral, and the distances between the two ends of the first arc segment 501 and the center line of the pericardial sheet 2 are unequal. At the same time, the two first arc segments 501 in the same support frame 5 are staggered in the circumferential direction. At the same time, due to the different lengths of the two second arc segments 502 in the same support frame 5, the difference in length is used to make the distances between the two third arc segments 503 and the aortic valve 1 different, that is, the two third arc segments 503 in the same support frame 5 are staggered in the vertical direction. The above staggered arrangement allows the support frame 5 to fold together during the contraction process, reducing the volume of the device after contraction, making it easier to install the device. At the same time, after the device is installed, the support frame 5 expands and squeezes the annular sleeve 202 to prevent the aortic wall from squeezing the annular sleeve 202 during the contraction process to cause wrinkles and bending, that is, to ensure that the pericardial sheet 2 is always in close contact with the aortic wall to prevent the occurrence of paravalvular leakage.

[0027] The arc segment 4011, the wave segment 402, the first circular ring segment 403, the second circular ring segment 404 and the first arc segment 501 are all memory metals, which are used to change their shapes at different temperatures. This design makes the valve support 4 of the device an automatic expansion structure. By placing the device in cold water, the arc segment 4011, the wave segment 402, the first circular ring segment 403, the second circular ring segment 404 and the first arc segment 501 gradually soften and shrink to varying degrees. Subsequently, the above-mentioned installation operation is performed using existing equipment. After the device is moved to the specified position, as the temperature rises, the arc segment 4011, the wave segment 402, the first circular ring segment 403, the second circular ring segment 404 and the first arc segment 501 gradually reverse their deformation and reset, and at the same time they gradually harden.

[0028] In the above scheme, by further supplementing the design of the valve support 4 structure, the fitting stability between the pericardial piece 2 and the aortic wall is improved, and paravalvular leakage of the aortic valve 1 is further avoided, thereby improving the working stability of the device.

[0029] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope provided by the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A novel suture-free aortic valve, characterized in that: Included are: Aortic valve (1); The pericardial sheet (2) is mounted on the valve ring of the aortic valve (1), and the valve ring of the aortic valve (1) is located in the middle of the pericardial sheet (2), so that the pericardial sheet (2) forms skirts on both sides of the valve ring of the aortic valve (1) to block blood flow; A valve support (4) is mounted on the pericardium (2); the valve support (4) is deformed to fit closely against the aortic wall, thereby providing support for the pericardium (2) and the aortic valve (1).

2. A novel suture-free aortic valve according to claim 1, characterized in that: The pericardium sheet (2) is composed of an annular protrusion (201) and two symmetrically distributed annular sleeves (202); The annular protrusion (201) is connected to the valve ring of the aortic valve (1), and is U-shaped in a cross-sectional view in the direction of the centerline of the pericardial sheet (2), and wraps around the valve ring of the aortic valve (1); the annular protrusion (201) is sutured with first coils (3) distributed equidistantly in the circumferential direction, and the first coils (3) penetrate the aortic valve (1); The two annular sleeves (202) are located at two ends of the annular protrusion (201), and the aortic valve (1) is located in the middle of the annular sleeves (202).

3. A novel suture-free aortic valve according to claim 2, characterized in that: The annular sleeve (202) is trumpet-shaped, and the diameter of the annular sleeve (202) gradually decreases from both ends to the middle of the pericardial sheet (2).

4. A novel suture-free aortic valve according to claim 2, characterized in that: The valve support (4) is composed of vertical segments (401) distributed equidistantly in the circumferential direction, wavy segments (402) distributed equidistantly in the circumferential direction, a first circular ring segment (403) and a second circular ring segment (404); The vertical section (401) is located between the aortic valve (1) and the pericardium (2); The wave segments (402) are fixedly connected to the adjacent vertical segments (401), and the wave segments (402) and the vertical segments (401) distributed at equal intervals correspond to each other one by one; The first annular segment (403) is fixedly connected to the wave segments (402) which are equidistantly distributed in the circumferential direction, and is arranged in a circumferential wave shape; The second circular ring segment (404) is fixedly connected to the first circular ring segment (403) and is arranged in a circumferential wave shape.

5. The novel suture-free aortic valve according to claim 4, characterized in that: The vertical section (401) comprises: The circular arc segment (4011) is located on the vertical segment (401), the circular arc segment (4011) is used to clamp the valve ring of the aortic valve (1), and the annular protrusion (201) wraps around the circular arc segment (4011).

6. The novel suture-free aortic valve according to claim 4, characterized in that: The wavelength of the waves on the first circular segment (403) is greater than the wavelength of the waves on the second circular segment (404), and the ratio of the two wavelengths is an integer.

7. The novel suture-free aortic valve according to claim 4, characterized in that: The first circular ring segment (403) and the second circular ring segment (404) form an annular structure, wherein the diameters at both ends of the annular structure are smaller than the diameter in the middle.

8. The novel suture-free aortic valve according to claim 4, characterized in that: The pericardial sheet (2) further comprises: a plurality of groups of second coils (301) equidistantly distributed in the circumferential direction, the number of the groups being the same as the number of leaflets of the aortic valve (1), the plurality of groups of the second coils (301) being respectively sutured to the connection between two adjacent leaflets of the aortic valve (1), and the vertical section (401) close to the two adjacent leaflets of the aortic valve (1) being sutured between the two leaflets, the second coils (301) being cross coils; A plurality of groups of third coils (302) equidistantly distributed in the circumferential direction are respectively sutured to the connection between two adjacent leaflets of the aortic valve (1) and the adjacent annular sleeve (202), and the third coils (302) wrap around the adjacent vertical segments (401).

9. The novel suture-free aortic valve according to claim 4, characterized in that: It also includes a circumferentially distributed support frame (5): The support frames (5) distributed in the circumferential direction are respectively fixed to two adjacent vertical sections (401); the support frames (5) are made of elastic material, and are used to squeeze the adjacent annular sleeves (202) and expand them outwards; The support frame (5) is composed of a first arc segment (501), two second arc segments (502) and two third arc segments (503); the first arc segment (501) is spiral-shaped; the distances between the two ends of the first arc segment (501) and the center line of the pericardium sheet (2) are different; and the lengths of the two second arc segments (502) are different.

10. The novel suture-free aortic valve according to claim 9, characterized in that: The circular arc segment (4011), the wave segment (402), the first circular ring segment (403), the second circular ring segment (404) and the first arc segment (501) are all memory metals, which are used to change their shapes at different temperatures.

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