Disclosure of Invention
Based on this, it is necessary to provide a unicondylar femoral prosthesis system and a unicondylar femoral prosthesis that better conform to the anatomy of the human body and avoid situations where the distal femur or the posterior femur is not adequately covered or is unstable.
The unicondylar femoral prosthesis system comprises N unicondylar femoral prostheses with gradually increased sizes, wherein N is more than or equal to 2, the ratio of the anterior-posterior diameter of each unicondylar femoral prosthesis to the posterior condyle height of the unicondylar femoral prosthesis is increased along with the increase of the sizes of the unicondylar femoral prostheses, the anterior-posterior diameter is the maximum length of the unicondylar femoral prosthesis in the horizontal direction, and the posterior condyle height is the maximum height of the unicondylar femoral prosthesis in the vertical direction.
In one embodiment, the ratio of the anterior-posterior diameter to the posterior condyle height ranges from 1.2 to 1.6.
In one embodiment, the unicondylar femoral prosthesis further comprises a overhang protruding from the posterior condylar cortical bone of the human femur, the ratio of the anterior-posterior diameter ratio to the difference between the height of the posterior condylar and the height of the overhang increasing as the size of the unicondylar femoral prosthesis increases.
In one embodiment, the ratio of the difference between the posterior condylar height and the overhang height over the anterior-posterior aspect ratio is in the range of 1.2-1.6.
In one embodiment, the ratio of the anterior-posterior diameter to the posterior condylar height, or the ratio of the difference between the posterior condylar height and the height of the overhang over the anterior-posterior diameter, satisfies the following condition:
The value range of the unicondylar femoral prosthesis is 1.28-1.34 for the unicondylar femoral prosthesis with the anterior-posterior diameter of 40mm less than or equal to AP less than or equal to 50mm, the value range of the unicondylar femoral prosthesis with the anterior-posterior diameter of 50mm less than or equal to AP less than or equal to 55mm is 1.34-1.40, and the value range of the unicondylar femoral prosthesis with the anterior-posterior diameter of 55mm less than or equal to AP less than or equal to 65mm is 1.40-1.46.
In one embodiment, the unicondylar femoral prosthesis comprises an articular surface for cooperation with the tibial insert, the articular surface comprising a distal articular surface, a posterior condylar articular surface, and a posterior epicondylar articular surface connected in sequence, the distal articular surface having a first radius of curvature in the sagittal plane, the posterior condylar articular surface having a second radius of curvature in the sagittal plane, the posterior epicondylar articular surface having a third radius of curvature in the sagittal plane, and the first radius of curvature being greater than the second radius of curvature, the second radius of curvature being greater than the third radius of curvature.
In one embodiment, the ratio of the first radius of curvature to the second radius of curvature of the unicondylar femoral prosthesis is a constant value.
In one embodiment, the ratio of the first radius of curvature to the second radius of curvature of the unicondylar femoral prosthesis is in the range of 1.65-1.95.
In one embodiment, the radius of curvature of the articular surface on the coronal plane is a fourth radius of curvature, the fourth radius of curvature being equal to the second radius of curvature.
In one embodiment, the anterior end of the unicondylar femoral prosthesis has a medial height in the coronal plane direction that is less than a lateral height of the anterior end of the unicondylar femoral prosthesis.
In one embodiment, the anterior end of the unicondylar femoral prosthesis includes a first articular surface proximate a medial side of the unicondylar femoral prosthesis and a second articular surface proximate a lateral side of the unicondylar femoral prosthesis, an intersection of the first articular surface and the second articular surface on the coronal surface forming a lowest point of the unicondylar femoral prosthesis on the coronal surface that coincides with a centerline of the unicondylar femoral prosthesis, and a radius of curvature of the first articular surface on the coronal surface that is less than a radius of curvature of the second articular surface on the coronal surface.
In one embodiment, the anterior end of the unicondylar femoral prosthesis includes a first articular surface proximate a medial side of the unicondylar femoral prosthesis and a second articular surface proximate a lateral side of the unicondylar femoral prosthesis, an intersection of the first articular surface and the second articular surface on the coronal surface forming a nadir of the unicondylar femoral prosthesis on the coronal surface that is offset a first distance relative to a centerline of the unicondylar femoral prosthesis in a direction proximate the lateral side of the unicondylar femoral prosthesis, and a radius of curvature of the first articular surface on the coronal surface is equal to a radius of curvature of the second articular surface on the coronal surface.
In one embodiment, the anterior end of the unicondylar femoral prosthesis includes a first articular surface proximate a medial side of the unicondylar femoral prosthesis and a second articular surface proximate a lateral side of the unicondylar femoral prosthesis, an intersection of the first articular surface and the second articular surface on the coronal surface forming a nadir of the unicondylar femoral prosthesis that is offset a second distance relative to a centerline of the unicondylar femoral prosthesis in a direction proximate the lateral side of the unicondylar femoral prosthesis, and a radius of curvature of the first articular surface on the coronal surface is less than a radius of curvature of the second articular surface on the coronal surface.
The unicondylar femoral prosthesis comprises an anterior-posterior diameter and a posterior-condyle height, wherein the anterior-posterior diameter is the maximum length of the unicondylar femoral prosthesis in the horizontal direction, the posterior-condyle height is the maximum height of the unicondylar femoral prosthesis in the vertical direction, the ratio of the anterior-posterior diameter to the posterior-condyle height ranges from 1.28 to 1.34 for the unicondylar femoral prosthesis with the anterior-posterior diameter of 40mm less than or equal to AP <50mm, the ratio of the anterior-posterior diameter to the posterior-condyle height ranges from 1.34 to 1.40 for the unicondylar femoral prosthesis with the anterior-posterior diameter of 50mm less than or equal to AP <55mm, and the ratio of the anterior-posterior diameter to the posterior-condyle height ranges from 1.40 to 1.46 for the unicondylar femoral prosthesis with the anterior-posterior diameter of 55mm less than or equal to 65 mm.
The unicondylar femoral prosthesis system is based on a human knee joint anatomical structure, and the ratio of the front diameter to the rear diameter to the height of the unicondylar femoral prosthesis is increased along with the increase of the size of the unicondylar femoral prosthesis by designing the unicondylar femoral prosthesis, so that the unicondylar femoral prosthesis is more in line with the human anatomical structure, the problems of insufficient coverage and instability of the distal femur or the rear femur condyle are reduced, the risk of postoperative pain of a patient is reduced, and the postoperative feeling of the patient is better.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application.
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic view of the structure of a unicondylar femoral prosthesis in the sagittal plane direction according to an embodiment;
FIG. 2 is a schematic cross-sectional view of the unicondylar femoral prosthesis shown in FIG. 1;
FIG. 3 is an exemplary table of anterior-posterior diameter, posterior condyle height, and aspect ratio for each unicondylar femoral prosthesis of a unicondylar femoral prosthesis system in one embodiment;
FIG. 4 is a graph of the fit of a unicondylar femoral prosthesis to a femur in another embodiment;
FIG. 5 is an exemplary table of anterior-posterior diameter, posterior condyle height, and aspect ratio of each unicondylar femoral prosthesis of a unicondylar femoral prosthesis system in another embodiment;
FIG. 6 is an exemplary table of radii of curvature for articular surfaces of a unicondylar femoral prosthesis according to one embodiment;
FIG. 7 is an exemplary table of radii of curvature for articular surfaces of a unicondylar femoral prosthesis according to another embodiment;
FIG. 8 is a cross-sectional view of the unicondylar femoral prosthesis shown in FIG. 1, taken at section A-A;
FIG. 9 is a cross-sectional view of another embodiment of a unicondylar femoral prosthesis at section A-A;
FIG. 10 is a cross-sectional view of yet another embodiment unicondylar femoral prosthesis at section A-A.
Reference numerals illustrate:
10. Articular surface, 11, distal articular surface, 12, posterior condylar articular surface, 13, posterior epicondylar articular surface, 14, overhang portion, 15, first articular surface, 16, second articular surface, 20, osteotomy surface, 21, distal osteotomy surface, 22, posterior condylar osteotomy surface, 23, posterior epicondylitis osteotomy surface, P1, nadir, P2, nadir, P3, posterior end point, P4, anterior end point.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.
In order to better explain the technical solution of the present invention, first, the azimuth names involved in each embodiment are explained:
The sagittal plane refers to a longitudinal section dividing the human body or the prosthesis into a left part and a right part in the front-back direction, wherein the sagittal plane passing through the middle of the human body or the prosthesis is the middle sagittal plane, and the sagittal plane divides the human body or the prosthesis into two parts with the same left and right parts.
The coronal plane refers to a longitudinal section from left to right, dividing the body or prosthesis into front and rear parts, which is perpendicular to the sagittal plane.
The cross section, also called the horizontal plane, is a plane parallel to the ground plane that divides the body or prosthesis into upper and lower parts, the plane being perpendicular to the coronal and sagittal planes.
Medial side is the side relatively close to the median sagittal plane of the human body.
Outside, the side relatively far from the median sagittal plane of the human body.
Anterior, the side on the sagittal plane that is relatively close to the abdomen.
Posterior-sagittal-side relatively close to the back.
Referring to fig. 1-3, fig. 1 shows a schematic view of a unicondylar femoral prosthesis according to an embodiment of the present application in a sagittal plane direction, and fig. 2 shows a schematic view of a unicondylar femoral prosthesis according to an embodiment of the present application in a transverse plane direction. Fig. 3 is a table comparing the anterior-posterior diameter AP, the posterior condyle height H, and the ratio thereof for each unicondylar femoral prosthesis of the unicondylar femoral prosthesis system in one embodiment of the present application. Specifically, as shown in fig. 3, the unicondylar femoral prosthesis system according to an embodiment of the present application includes a set of unicondylar femoral prostheses with gradually increasing sizes, and the number of unicondylar femoral prostheses in the set of unicondylar femoral prostheses is N, n+.2. Herein, the "size" of the unicondylar femoral prosthesis refers to the anterior-posterior diameter AP of the unicondylar femoral prosthesis. As shown in fig. 3, in the unicondylar femoral prosthesis system, the ratio AP/H of the anterior-posterior diameter AP of each unicondylar femoral prosthesis to the posterior condyle height H of the unicondylar femoral prosthesis increases as the size of the unicondylar femoral prosthesis increases.
Specifically, referring to fig. 1, the unicondylar femoral prosthesis includes a articular surface 10 for mating with the tibial insert, the articular surface 10 including a distal articular surface 11, a posterior condylar articular surface 12, and a posterior epicondylar articular surface 13 that are connected in sequence from anterior to posterior. The back of the joint surface 10 is an osteotomy surface 20 for contacting the femur of a human body, the osteotomy surface 20 comprises a distal osteotomy surface 21, a posterior condylar osteotomy surface 22 and a posterior epicondylitis osteotomy surface 23 which are sequentially connected from the anterior side to the posterior side, wherein the distal osteotomy surface 21 is opposite to the distal joint surface 11, the posterior condylar osteotomy surface 22 is opposite to the posterior condylar articular surface 12, the posterior epicondylitis osteotomy surface 23 is opposite to the posterior epicondylitis articular surface 13, the osteotomies 20 are all planes, and the osteotomies 20 are all straight lines when viewed from the sagittal plane. The point of the distal joint surface 11 which is the farthest from the perpendicular distance of the distal osteotomy surface 21 is the lowest point P1 of the prosthesis, and this lowest point P1 corresponds to the lowest point of the prosthesis when the prosthesis is implanted in a human body. The posterior epicondylar articular surface 13 terminates at the highest point P2 of the prosthesis. The point on the posterior epicondylar articular surface 13 that is furthest from the perpendicular to the posterior epicondylar osteotomy surface 23 is the posterior endpoint P3 of the prosthesis. The end point of the distal articular surface 11 is the anterior end point P4 of the prosthesis.
The circle center corresponding to the circular arc of the distal joint surface 11 is point C, the direction in which the straight line connecting the lowest point P1 of the prosthesis and the point C of the circle center is located is the vertical direction of the prosthesis, and the direction perpendicular to the vertical direction is the horizontal direction. The posterior condyle height H of the prosthesis refers to the maximum height of the prosthesis in the vertical direction, i.e., the distance from the lowest point P1 to the highest point P2 of the prosthesis in the vertical direction. The anterior-posterior diameter AP of the prosthesis refers to the maximum length of the prosthesis in the horizontal direction, i.e., the distance from the posterior end point P3 to the anterior end point P4 of the prosthesis in the horizontal direction.
The anatomical characteristics of the ratio of the anterior-posterior diameter to the posterior condylar height of the unicondylar femoral prosthesis are not fully considered in the design of the traditional unicondylar femoral prosthesis, and generally, the ratio of the anterior-posterior diameter to the posterior condylar height of the unicondylar femoral prosthesis is reduced with the size of the unicondylar femoral prosthesis or the ratio of the anterior-posterior diameter to the posterior condylar height of the unicondylar femoral prosthesis is almost unchanged with the size of the unicondylar femoral prosthesis. The applicant of the present application, through extensive studies on human femur anatomical data, found that the ratio of the anterior-posterior diameter to the posterior condylar height of the femur after the surgical resection actually increased as the femur size increased. The unicondylar femoral prosthesis system is based on a human knee joint anatomical structure, and the ratio AP/H of the front diameter AP and the rear diameter AP of the unicondylar femoral prosthesis to the rear height H is increased along with the increase of the size of the unicondylar femoral prosthesis, so that the unicondylar femoral prosthesis is more in line with the human anatomical structure, the problems of insufficient coverage and instability of the distal femur or the rear femur condyle of the femur are reduced, the risk of postoperative pain of a patient is reduced, and the postoperative feeling of the patient is better.
Further, referring to fig. 3, the anterior-posterior diameter AP and the posterior condyle height H of the unicondylar femoral prosthesis are both in mm in the table of fig. 3. The ratio of anterior-posterior diameter AP to posterior condylar height H of the unicondylar femoral prosthesis, AP/H (hereinafter referred to as the aspect ratio), ranges from 1.2 to 1.6, preferably from 1.3 to 1.45. Further, for small-sized unicondylar femoral prostheses (40 mm. Ltoreq. AP <50 mm), the range of values for the length to height ratio AP/H is 1.28-1.34, for medium-sized unicondylar femoral prostheses (50 mm. Ltoreq. AP <55 mm), the range of values for the length to height ratio AP/H is 1.34-1.40, and for large-sized prostheses (55 mm. Ltoreq. AP. Ltoreq.65 mm), the range of values for the length to height ratio AP/H is 1.40-1.46. Further, if there is a number or a greater number of sizes for the unicondylar femoral prosthesis of the unicondylar femoral prosthesis system, the ratio of the aspect ratio AP/H of the adjacent size unicondylar femoral prosthesis should be greater than or equal to the aspect ratio AP/H of the small size unicondylar femoral prosthesis and less than or equal to the aspect ratio AP/H of the large size unicondylar femoral prosthesis.
Further, referring to fig. 4, in another embodiment, the unicondylar femoral prosthesis further comprises a overhanging portion 14, wherein the overhanging portion 14 protrudes from the posterior condylar cortical bone of the human femur, i.e., the height thereof exceeds the contact point of the posterior condylar cortical bone of the human femur with the unicondylar femoral prosthesis, so that the top of the unicondylar femoral prosthesis is suspended from contact with the femur. Specifically, the overhang portion 14 of the unicondylar femoral prosthesis is the portion of the unicondylar femoral prosthesis that protrudes above the posterior condylar cortical bone of the human femur after the unicondylar femoral prosthesis is installed on the human joint. Further, referring to fig. 5, the ratio of anterior-posterior diameter AP to the difference between the superior-posterior condylar height H and the height L of the overhang 14 increases as the size of the unicondylar femoral prosthesis increases. As shown in fig. 4, the height L of the overhang portion 14 is the height of the posterior condylar portion of the unicondylar femoral prosthesis beyond the posterior condylar cortical bone of the human femur on the sagittal plane, and preferably the height L of the overhang portion 14 increases with the size of the unicondylar femoral prosthesis. In this embodiment, the ratio of the anterior-posterior diameter AP to the difference between the superior-posterior condyle height H and the height L of the overhang 14 is AP/(H-L), and the value of AP/(H-L) increases as the size of the unicondylar femoral prosthesis increases.
As shown in FIG. 5, in this embodiment, the relationship AP/(H-L) between anterior-posterior diameter AP and posterior condylar height H ranges from 1.2 to 1.6, and this ratio increases as the size of the unicondylar femoral prosthesis increases. Further, in the present embodiment, the height L of the overhang 14 of the unicondylar femoral prosthesis ranges from 1mm to 3mm. The back condyle height of the unicondylar femoral prosthesis is properly suspended by 1mm-3mm, and the suspension height L is increased along with the increase of the size of the unicondylar femoral prosthesis, so that the better connection between the back condyle of the unicondylar femoral prosthesis and the soft tissue can be ensured, and the stability of the unicondylar femoral prosthesis is improved. Preferably, the ratio of AP/(H-L) is in the range of 1.3 to 1.45. Further, the value of AP/(H-L) ranges from 1.28 to 1.34 for small-sized unicondylar femoral prosthesis (AP <50mm, height L=1 mm of overhang 14) and from 1.34 to 1.40 for medium-sized unicondylar femoral prosthesis (AP <55mm, height L=2 mm of overhang 14), and from 1.40 to 1.46 for large-sized prosthesis (AP < 65mm, height L=3 mm of overhang 14).
Further, referring to fig. 1, the distal articular surface 11 has a first radius of curvature R1 in the sagittal plane, the posterior condylar articular surface 12 has a second radius of curvature R2 in the sagittal plane, the posterior epicondylar articular surface 13 has a third radius of curvature R3 in the sagittal plane, and the first radius of curvature R1 is greater than the second radius of curvature R2 and the second radius of curvature R2 is greater than the third radius of curvature R3. By having the second radius of curvature R2 greater than the third radius of curvature R3 in the unicondylar femoral prosthesis, the posterior condyles of the unicondylar femoral prosthesis can be tucked inwardly, and the posterior condyle flexion angle of the unicondylar femoral prosthesis can be made greater, which can improve joint mobility. In addition, the posterior condylar height H may be adjusted by adjusting the third radius of curvature R3, which may make the aspect ratio AP/H of the unicondylar femoral prosthesis more consistent with the recommended aspect ratio.
Further, as shown in fig. 6-7, the ratio of the first radius of curvature R1 to the second radius of curvature R2 of the unicondylar femoral prosthesis is a constant value, i.e., the ratio of the first radius of curvature R1 to the second radius of curvature R2 of the unicondylar femoral prosthesis does not change with the size of the unicondylar femoral prosthesis. Preferably, the ratio of the first radius of curvature R1 to the second radius of curvature R2 of the unicondylar femoral prosthesis ranges from 1.65 to 1.95. The applicant found that the anatomical feature of the femoral condyle of the human body is that the ratio of the distal radius of curvature of the femur in the sagittal plane to the posterior radius of curvature of the femur in the sagittal plane is in the range of 1.45-2.1, and that the ratio of the distal radius of curvature of the femur in the sagittal plane to the posterior radius of curvature of the femur in the sagittal plane has poor dimensional correlation with the femoral condyle. Therefore, the ratio of the first curvature radius R1 to the second curvature radius R2 of the unicondylar femoral prosthesis adopts a fixed value, so that the unicondylar femoral prosthesis is more suitable for most patients, and compared with a floating ratio, the unicondylar femoral prosthesis with the fixed value ratio is less prone to the situation that the matching difference is overlarge after being implanted into the patients.
Further, referring to fig. 2, the articular surface 10 has a fourth radius of curvature R4 on the coronal plane, and the fourth radius of curvature R4 is equal to the second radius of curvature R2, i.e., the posterior condylar articular surface 12 of the unicondylar femoral prosthesis has a spherical configuration. Because the femoral posterior condyle of the natural knee is approximately spherical, the posterior condylar articular surface 12 condyle of the designed unicondylar femoral prosthesis has the same radius of curvature on the sagittal plane and the coronal plane, i.e., r2=r4, thereby realizing the anatomical reconstruction of the natural knee and improving the stability of the articular surface.
Referring to fig. 8-10, in the coronal direction, the medial height h1 of the anterior end of the unicondylar femoral prosthesis is less than the lateral height h2 of the anterior end of the unicondylar femoral prosthesis. By reducing the medial height h1 of the anterior end of the condylar femoral prosthesis. Therefore, the front end of the condylar femoral prosthesis is lower than the soft tissue of the joint surface, and the collision between the single-condylar femoral prosthesis and the patella after being implanted into a human body is avoided, so that the postoperative feeling of a patient is improved. Preferably, the medial height h1 of the anterior end of the unicondylar femoral prosthesis is less than 2mm, preferably 1.5mm-1.6mm.
Referring specifically to fig. 8-10, an arbitrary cross-section A-A of the anterior end of a unicondylar femoral prosthesis (i.e., a cross-section of an arbitrary coronal plane) is illustrated. In one embodiment, the anterior end of the unicondylar femoral prosthesis includes a first articular surface 15 proximal to the medial side of the unicondylar femoral prosthesis and a second articular surface 16 proximal to the lateral side of the unicondylar femoral prosthesis, the intersection of the first articular surface 15 and the second articular surface 16 on the coronal plane forming the lowest point O of the unicondylar femoral prosthesis on the A-A cross-section. Further, there are many ways to reduce the medial height h1 of the anterior end of the condylar femoral prosthesis, such as shown in fig. 6 and 8, in one embodiment, the lowest point O coincides with the centerline m of the unicondylar femoral prosthesis, i.e., the offset of the lowest point O from the centerline m of the unicondylar femoral prosthesis toward the lateral side of the unicondylar femoral prosthesis is 0. And the radius of curvature R5 of the first articular surface 15 on the coronal plane is smaller than the radius of curvature R4 of the second articular surface 16 on the coronal plane, i.e., the medial height h1 of the anterior end of the unicondylar femoral prosthesis is reduced by reducing the radius of curvature of the first articular surface 15 on the coronal plane.
Referring to fig. 7 and 9, in another embodiment, the radius of curvature R5 of the first articular surface 15 on the coronal plane is equal to the radius of curvature R4 of the second articular surface 16 on the coronal plane, and the nadir O is offset from the centerline m of the unicondylar femoral prosthesis by a first distance n1 in a direction toward the lateral side of the unicondylar femoral prosthesis, preferably the first distance n1 decreases as the size of the unicondylar femoral prosthesis increases. Preferably, the first distance n1 ranges from 1mm to 1.4mm. Reducing the medial height of the anterior end of the unicondylar femoral prosthesis is achieved by offsetting the nadir O a first distance n1 relative to the centerline m of the unicondylar femoral prosthesis in a direction toward the lateral side of the unicondylar femoral prosthesis.
It should be noted that, in other embodiments, the two embodiments described above may be combined such that the medial height h1 of the anterior end of the condylar femoral prosthesis is reduced. Specifically, as shown in fig. 10, in one embodiment, the nadir is offset from the centerline of the unicondylar femoral prosthesis toward a direction approaching the lateral side of the unicondylar femoral prosthesis by a second distance n2, and the radius of curvature R5 of the first articular surface 15 on the coronal plane is smaller than the radius of curvature R4 of the second articular surface 16 on the coronal plane, thereby achieving a reduction in the medial height h1 of the anterior end of the unicondylar femoral prosthesis.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.