Patent Application
20150147722
The technical field relates to to a bionic fixing apparatus.
With the advances in technology and medicine, implants, such as bone screws, are used to fix the biological tissue in the human body for medical purpose, for example, for repairing accidental injury or nature aging.
However, modulus of elasticity of the conventional implants (which is about 100 Gpa) is much higher than that of the biological tissue in human body (which is lower than 1 Gpa). When the force applied is too high, the tissue tends to, necrosis, wear, and the implants may also be loosened. In general, the conventional process of manufacturing implants includes a special sintering process or a surface coating process to the implants, and then executing a surface treatment by laser to enhance bone integration. But the conventional process has limitation for improving the stress shielding effect of the implants. And the small size of implants may also increase the difficulty in a traditional process.
The disclosure is directed to a bionic fixing apparatus having a flexible portion. At least one trench is formed on the surface of the implants by additive manufacturing process, and the trench structure may effectively decrease modulus of elasticity of the implants to prevent the tissue from sagging, necrosis, wearing, or to prevent the implants from loosening.
According to one embodiment, a bionic fixing apparatus is provided. The bionic fixing apparatus includes a flexible portion having at least one trench. The trench is disposed on the surface of the flexible portion and has a first end and a second end. An interval is disposed between the first end and the second end. The trench is disposed for spreading the stress applied on the bionic fixing apparatus and preventing stress concentration and stress shielding.
In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
The bionic fixing apparatus according to the embodiment of the disclosure includes a flexible portion having at least one trench. The trench is disposed on the surface of the flexible portion and has a first end and a second end. An interval is disposed between the first end and the second end. That is, the first end and the second end disconnect to each other, and the trench is not formed as an enclosed region. In the embodiment, the trench is disposed for spreading the stress applied on the bionic fixing apparatus.
The following first to seventh embodiments are described with reference to the
In the embodiments of the disclosure, the track is an arc line with radian less than 2π. For, example, track T1 shown in
It should be noted that although track T1 shown in
The above-mentioned trench 11 observed in the first plane (X-Y plane) and the second plane (Y-Z plane) is shown by simplifying the bionic fixing apparatus according to the first embodiment of the disclosure to have a cylindrical, cone or similar shapes. That is, the trench 11 may be disposed substantially along the circumferential direction of the cylinder or cone, and extended on the surface of the flexible portion 10.
Since the bionic fixing apparatus 1 according to the first embodiment of the disclosure includes the trench 11, a small space formed by the trench may be used as a buffer when the bionic fixing apparatus 1 is subjected to an external force. For example, assumed that a 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus 1, the bionic fixing apparatus 1 may generate a displacement of approximately 4.998×10−2 mm. The displacement may be used as a buffer when the bionic fixing apparatus 1 is subjected to an external force, which prevents stress concentration and stress shielding, such that modulus of elasticity of the bionic fixing apparatus 1 may be decreased effectively to prevent the bionic fixing apparatus 1 from loosening or to prevent the tissue of organisms from sagging, necrosis, wearing.
The following is an observation of the structure of the first trench 21 and the second trench 22 of the bionic fixing apparatus 2 from another point of view (another plane). In this embodiment, the first trench 21 of the bionic fixing apparatus 2 is disposed along track T1 in X-Y plane as shown in FIG. 1C, and extended on the surface of the flexible portion 20. That is, the first trench 21 is disposed along an arc line along radian 0 to π, and extended on the surface of the flexible portion 20. The second trench 22 of the bionic fixing apparatus 2 is disposed along track T3 in X-Y plane as shown in
It is not limited that the first trench 21 and the second trench 22 according to the second embodiment of the disclosure are both arc lines with radian equal to π. In fact, the track according to the embodiment of the disclosure is an arc line with radian less than 2π. That is, a trench having a first end and a second end disconnected to each other may be the first trench 21 and the second trench 22 according to the embodiment of the disclosure.
In this embodiment, assumed that a 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus 2, the bionic fixing apparatus 2 may generate a displacement of approximately 3.647×10−2 mm. Assumed that a 137 N external force parallel with Z-direction is applied to the bionic fixing apparatus 2, the bionic fixing apparatus 2 may generate a displacement of approximately 4.996×10−2 mm. Similarly, the displacement may be used as a buffer when the bionic fixing apparatus 2 is subjected to an external force, such that modulus of elasticity of the bionic fixing apparatus 2 may be decreased effectively.
As shown in
The following is an observation of the structure of the first trench 31, the second trench 32, the third trench 33 and the fourth trench 34 of the bionic fixing apparatus 3 from another point of view (another plane). In this embodiment, the first trench 31 and the third trench 33 of the bionic fixing apparatus 3 are disposed along track T1 in X-Y plane as shown in
It is not limited that the first trench 31, the second trench 32, the third trench 33 and the fourth trench 34 according to the third embodiment of the disclosure are all arc lines with radian equal to π. In fact, the track according to the embodiment of the disclosure is an arc line with radian less than 2π. That is, a trench having a first end and a second end disconnected to each other may be the first trench 31, the second trench 32, the third trench 33 and the fourth trench 34 according to the embodiment of the disclosure.
In this embodiment, assumed that a 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus 3, the bionic fixing apparatus 3 may generate a displacement of approximately 7.731×10−2 mm. The displacement may be used as a buffer when the bionic fixing apparatus 3 is subjected to an external force, such that modulus of elasticity of the bionic fixing apparatus 3 may be decreased effectively.
As shown in
The following is an observation of the structure of the first trench 41, the second trench 42, the third trench 43 and the fourth trench 44 of the bionic fixing apparatus 4 from another point of view (another plane). In this embodiment, the first trench 41 of the bionic fixing apparatus 4 is disposed along track T2 in X-Y plane as shown in
It is not limited that the first trench 41, the second trench 42, the third trench 43 and the fourth trench 44 according to the fourth embodiment of the disclosure are all arc lines with radian equal to π. In fact, the track according to the embodiment of the disclosure is an arc line with radian less than 2π. That is, a trench having a first end and a second end disconnected to each other may be the first trench 41, the second trench 42, the third trench 43 and the fourth trench 44 according to the embodiment of the disclosure.
In this embodiment, assumed that a 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus 4, the bionic fixing apparatus 4 may generate a displacement of approximately 9.533×10−2 mm. The displacement may be used as a buffer when the bionic fixing apparatus 4 is subjected to an external force, such that modulus of elasticity of the bionic fixing apparatus 4 may be decreased effectively.
The difference between the bionic fixing apparatus 5 according to the fifth embodiment of the disclosure and the bionic fixing apparatus 4 according to the fourth embodiment of the disclosure is the order of the second trench 52 and the third trench 53 in the bionic fixing apparatus 5 and the order of the second trench 42 and the third trench 43 of the bionic fixing apparatus 4. As shown in
The following is an observation of the structure of the bionic fixing apparatus 5 from another point of view (another plane). In this embodiment, the second trench 52 of the bionic fixing apparatus 5 is disposed along track T3 in X-Y plane as shown in
The first trench 51, the second trench 52, the third trench 53 and the fourth trench 54 according to the fifth embodiment of the disclosure are all arc lines with radian equal to π. However, the disclosure is not limited thereto.
In this embodiment, assumed that a 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus 5, the bionic fixing apparatus 5 may generate a displacement of approximately 1.087×10−1 mm. The displacement may be used as a buffer when the bionic fixing apparatus 5 is subjected to an external force, such that modulus of elasticity of the bionic fixing apparatus 5 may be decreased effectively.
In the first embodiment to the fifth embodiment mentioned above, a 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus, and the displacement of the bionic fixing apparatus is measured. Similarly, a bionic fixing apparatus of a comparative example is proceeded a stress test, and compared with the bionic fixing apparatus of the first embodiment to the fifth embodiment. Here, the bionic fixing apparatus of the comparative example does not include any flexible portion. That is, the bionic fixing apparatus of the comparative example does not have any trench or pore on the surface.
A 100 N external force parallel with Z-direction is applied to the bionic fixing apparatus of the comparative example, and the bionic fixing apparatus of the comparative example may generate a displacement of approximately 9.023×10−4 mm, which is much smaller than the displacement of the embodiments mentioned above. That is, the structure of the comparative example could not be a buffer when subjected to an external force, and the bionic fixing apparatus of the comparative example is easily loosened, or make the tissue of organisms sag, necrosis, wear.
For example, the first trench 61 has a first end 611 and a second end 612; the second trench 62 has a first end 621 and a second end 622; the third trench 63 has a first end 631 and a second end 632; the fourth trench 64 has a first end 641 and a second end 642. An interval S is disposed between the first ends 611, 621, 631, 641 and the second ends 612, 622, 632, 642. That is, the first end 611 and the second end 612 disconnect to each other, the first end 621 and the second end 622 disconnect to each other, the first end 631 and the second end 632 disconnect to each other, and the first end 641 and the second end 642 disconnect to each other, such that the first trench 61, the second trench 62, the third trench 63 and the fourth trench 64 are not formed as enclosed regions.
The first trench 61, the second trench 62, the third trench 63 and the fourth trench 64 according to the sixth embodiment of the disclosure are similar to the trench 11 according to the first embodiment of the disclosure, and would not be narrated more herein. It should be noted that the first trench 61, the second trench 62, the third trench 63 and the fourth trench 64 are formed along an arc line with radian larger than π and smaller than 2π, and extended on the surface of the flexible portion 60 as shown in
In this embodiment, the bionic fixing apparatus further includes a fifth trench 65 and a sixth trench 66 disposed on the surface of the flexible portion 60. The fifth trench 65 and the sixth trench 66 are U-shaped, and openings of the two U-shaped trenches are opposed to each other. As shown in
In addition, the bionic fixing apparatus 6 according to the sixth embodiment of the disclosure may include a thread portion 91 surrounded on the surface of the bionic fixing apparatus 6, and the thread portion 91 and the flexible portion 60 are one-piece formed. After the bionic fixing apparatus 6 is implanted in an organism, the thread portion 91 may help the bionic fixing apparatus 6 to fix in the surrounding biological tissue.
In the seventh embodiment, the bionic fixing apparatus 7 may further include a plurality of pores 72, 73, 74. In this embodiment, the pore 72 may be triangular, the pore 73 may be trapezoidal, and the pore 74 may be a shape combined with triangle (or trapezoid) and rectangle. These pores and the trench 71 may form a plurality of stress-bearing areas 75 on the surface of the flexible portion 70.
In the embodiment, the stress-bearing areas 75 include a first sub-area 751 and a second sub-area 752. The first sub-area 751 is disposed along a first direction D1 perpendicular to a force-receiving direction of the bionic fixing apparatus 7. An included angle between first sub-area 751 and the second sub-area 752 is a first angle θ1, and the first angle θ1 may range between 0 and 45 degrees. Since the bionic fixing apparatus 7 according to the seventh embodiment includes the trench 71 and the plurality of pores 72, 73, 74, the stress-bearing areas 75 are formed on the surface of the flexible portion 70, such that the bionic fixing apparatus 7 may spread the stress from outside and prevent stress concentration and stress shielding, and the modulus of elasticity of the bionic fixing apparatus 7 may be effectively decreased to prevent the bionic fixing apparatus 7 from loosening.
It should be noted that although the pore 72 is triangular, the pore 73 is trapezoidal, and the pore 74 is a shape combined with triangle (or trapezoid) and rectangle according to the seventh embodiment of the disclosure, the disclosure is not limited thereto. Instead, the shape of the pores may correspond to the trench 71 to form a plurality of stress-bearing areas 75, and the stress-bearing areas 75 should include a first sub-area 751 extended along the first direction D1 and a second sub-area 752, wherein an included angle between first sub-area 751 and the second sub-area 752 ranges between 0 and 45 degrees. If the included angle (first angle θ1) is larger than 45 degrees, then the modulus of elasticity of the bionic fixing apparatus 7 would significantly increase.
In addition, the bionic fixing apparatus 7 according to the seventh embodiment of the disclosure may also include a thread portion 91 surrounded on the surface of the bionic fixing apparatus 7, and the thread portion 91 and the flexible portion 70 are one-piece formed.
The complex micro-structure in the embodiments mentioned above may be manufactured by an additive manufacturing (AM) process. The trenches of the flexible portion, or the stress-bearing areas and the thread portion in some embodiments are all one-piece formed. Further, various shapes and arrangements according to the embodiments of the disclosure may be easily completed by the additive manufacturing process. On the contrary, the conventional process (including a special sintering process or a surface coating process to the implants, and then executing a surface treatment by laser to enhance bone integration) is not only more complex, but also needs more manufacturing cost, which is not suitable to manufacture the structures in the embodiments of the disclosure.
According to the embodiments of the disclosure, a material of the bionic fixing apparatus may include metals, alloys, ceramics or polymeric biomaterials. In some embodiments, the bionic fixing apparatus may be a hollow structure. The hollow structure may correspond to the trenches of the flexible portion to produce an atmosphere which is more suitable for cells or tissues of aquatic organisms growing.
It should be noted that a depth of the trench are not limited in the embodiments mentioned above. Then the bionic fixing apparatus is a hollow structure, the trench may be deep enough to reach the hollow portion of the bionic fixing apparatus. That is, the trench may be formed as a through hole penetrating from the surface of the flexible portion to the hollow portion. But the disclosure is not limited thereto. An interval may be formed between the trench and the hollow portion, such that the trench and the hollow portion are disconnected.
The bionic fixing apparatus according to the embodiments of the disclosure may be applied to fix different parts of the organism. For example, the bionic fixing apparatus may be applied to an artificial tooth root, vertebral screws, artificial discs, intramedullary nails or screws. Since the bionic fixing apparatus may be manufactured by the additive manufacturing process, it is easy to design different structures to correspond to different parts of the organism.
Compared with the fixing structure with high modulus of elasticity such as conventional bone nail, the bionic fixing apparatus according to the embodiments of the disclosure having the trench structure may effectively decrease modulus of elasticity of the implants to prevent the tissue of organisms from sagging, necrosis, wearing, or to prevent the implants from loosening.
In addition, the complex micro-structure in the embodiments mentioned above may be manufactured by an additive manufacturing process. The trenches of the flexible portion, or the stress-bearing areas and the thread portion in some embodiments are all one-piece formed. Further, various shapes and arrangements of the pores according to the embodiments of the disclosure may be easily completed by the additive manufacturing process. On the contrary, the conventional process (including a special sintering process or a surface coating process to the implants, and then executing a surface treatment by laser to enhance bone integration) is not only more complex, but also needs more manufacturing cost, which is not suitable to manufacture the structures in the embodiments of the disclosure.
The additive manufacturing process may also be known as rapid prototyping (RP), rapid manufacturing (RM) or 3D Printing. It is rectified as additive manufacturing process by American Society for Testing and Materials (ASTM) in 2009. Researchers have divided the additive manufacturing process into seven types as show in Table 1. The seven types include: Vat Photopolymerization, Material Jetting, Binder Jetting, Material Extrusion, Powder Bed Fusion, Sheet Lamination, and Directed Energy Deposition.
The characteristics of the additive manufacturing process are that the three-dimensional (3D) image is transferred to two-dimensional (2D) cross-sections, and products can be made layer by layer according to the two-dimensional cross-sections, to form a three-dimensional object. Compared with the conventional process, the additive manufacturing process may avoid wasting materials, and be more suitable for application of highly complicated structure, customized, and small or medium amount of production.
During the manufacturing process of the bionic fixing apparatus according to the embodiments of the disclosure, the 3D digital model of the bionic fixing apparatus is transferred to a 2D cross-section having thickness between 20-50 μm. And a feeding system will spread out a 20-50 μm thickness layer of powder materials (such as metals, alloys, ceramics or polymeric biomaterials) with particle size smaller than 25 μm in a low-oxygen atmosphere (concentration of O2 is smaller than 10,000 ppm).
Then, the fiber laser beam (with wavelength 1070 nm) is focused to the laminated area (50-150 μm) by the scanning galvanometer. The focused beam is moved corresponding to the 2D cross-sections (the moving speed is 500-1500 mm/s), such that the powder materials is heating up above their melting point to adding a layer of structure. By repeating this procedure, the 3D bionic fixing apparatus can be made layer by layer according to the 2D cross-sections. The additive manufacturing process may produce the highly complicated shapes, inner flow channels, and inner structures which are difficult to make by the conventional process.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103118970 | May 2014 | TW | national |
This application claims the benefits of U.S. provisional application 61/908,772, filed Nov. 26, 2013, and Taiwan application Serial No. 103118970, filed May 30, 2014, the disclosures of which are incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61908772 | Nov 2013 | US |
