Summary of the invention
Of the invention be according to the structure organization characteristic of mankind's nature femoral head, design can substitute necrosis or damage
The model of femoral head, to achieve the purpose that as bone graft substitute.
Technical solution of the present invention:
Bionical femur head model be by rod piece and node population at hemisphere dot matrix supporting structure, be divided into interior hemisphere dot matrix branch
Frame structure and outer hemisphere dot matrix supporting structure two parts;
Outer hemisphere dot matrix supporting structure is divided into top layer, four part of the second layer, third layer and bottom from top to bottom, from upper
It is successively increased to the spacing between lower adjacent two layers;Top layer is divided into vertex and lower surface, i.e. vertex and lower circle, and lower circle uses node 16
Equal part;The second layer, third layer and bottom, every layer is divided into upper and lower surfaces, i.e., upper round and lower circle;Upper circle and lower circle are all made of
16 equal part of node, each interlayer node location correspond to each other;
Interior hemisphere dot matrix supporting structure is divided into top layer and bottom two parts from top to bottom, from top to bottom between adjacent two layers
Spacing successively increase;Top layer is divided into vertex and lower surface, i.e. vertex and lower circle, and lower circle uses 8 equal part of node;Bottom is divided into
Surface and lower surface, i.e., upper round and lower circle;Upper circle and lower circle are all made of 8 equal part of node, and each interlayer node location corresponds to each other;
In outer hemisphere dot matrix supporting structure and interior hemisphere dot matrix supporting structure, the upper circle of the second layer, third layer and bottom
Adjacent two nodes, the adjacent two nodes of lower circle, upper circle two node corresponding with lower circle, the node of upper circle and lower circle are corresponding adjacent
Two nodes between be connected;Each node of lower circle of top layer is connected with vertex;It is connected between each node using connecting rod;
Node under bottom in interior hemisphere dot matrix supporting structure on circle is respectively and under outer hemisphere dot matrix supporting structure bottom
Corresponding node, corresponding adjacent two nodes connection on circle;Node under bottom in interior hemisphere dot matrix supporting structure on circle
It is connected respectively with the corresponding node on outer hemisphere dot matrix supporting structure bottom on circle, corresponding two adjacent nodes;
Under top layer in interior hemisphere dot matrix supporting structure circle on node respectively with the outer hemisphere dot matrix supporting structure second layer
Corresponding node, corresponding two adjacent nodes on lower circle are attached;Under top layer in interior hemisphere dot matrix supporting structure on circle
Node respectively on the outer hemisphere dot matrix supporting structure second layer on circle corresponding node, corresponding two adjacent nodes are connected
It connects;
Under top layer in interior hemisphere dot matrix supporting structure circle on node respectively with outer hemisphere dot matrix supporting structure third layer
Corresponding node, corresponding two adjacent nodes on lower circle are attached;
The center of circle under node and bottom under bottom in interior hemisphere dot matrix supporting structure on circle on circle is attached;
The vertex of interior hemisphere dot matrix supporting structure and the vertex of outer hemisphere dot matrix supporting structure are attached.
The characteristics of bionical femur head model:
1. dome-type.Because of the natural femoral head near hemispherical of the mankind;
2. dot matrix sandwich, model is entirely to be made of rod piece connection;
3. half spherical model extends layer by layer from inside to outside from the centre of sphere, n-layer sandwich can be theoretically formed;
4. the gradient distribution of entire model can be changed by the cross-sectional area of the rod piece of the different interlayers of control;
5. again may be by controlling the long gradient distribution to change entire model of bar of different interlayer rod pieces;In addition, gradient
Topological classes can substantially be divided into: outer to dredge interior close gradient, uniform gradient, outer close interior thin gradient.
Beneficial effects of the present invention: use for reference the true femoral head of the mankind characteristic, design future can substitute necrosis or damage
The model of bad bone, while bone graft substitute manufacture is carried out in time using 3D printing technique, so as to improve people's lives.
Specific embodiment
Below in conjunction with attached drawing and technical solution, a specific embodiment of the invention is further illustrated.
A kind of design method of bionical femur head model, steps are as follows:
(1) spherical coordinate system is established, that is, the coordinate put isR represents radius, and θ is represented and put in x-y plane with origin
Line and x-axis angle,The point in spherical coordinate system is represented with the line of origin and the angle of x-y plane;
(2) connecting rod between internal layer bar and internal layer and outer layer is established
(2.1) the first plane S1 plane for selecting origin first, is initially set to x-y plane;Radius is established in S1 plane
For three points adjacent on the circle of a, each point is 45 degree at central angle with center of circle institute, if first point is p1;It resettles with half
Diameter is three points adjacent on the circle of 2a, and each point is 22.5 degree at central angle with center of circle institute;
(2.2) change againIt is 22.5 degree, establishes three points adjacent on the circle that radius is 2a, Mei Gedian on that plane
With the center of circle institute at central angle be 22.5 degree;Change againIt is 45 degree, establishes adjacent on the circle that radius is a three on that plane
Point, each point and center of circle institute are 45 degree at central angle;It resettles flat about S1 with six points not in S1 plane in this step
Six corresponding points of face mirror symmetry, by p1, remaining all the points is attached with step (2);If the θ value of p1 is 180 degree,
The θ value of remaining point is also that the point of 180 degree is not connect with p1;
The θ value of p1 is increased by 45 degree, then this point is p2, repeatedly step (2) establishment process, and so on, altogether repeatedly 2
It is secondary;
(3) the remaining rod piece of circle under hemisphere bottom is connected
(3.1) in S1 plane, a point is established on the circle that radius is a, is set as p4;It is also built on the circle that radius is 2a
Found a point;
(3.2) rotary work plane makesIt is 22.5 degree, establishes a point on the circle that radius is 2a;Rotary work is flat
Face makesIt is 45 degree, establishes a point on the circle that radius is a;It resettles and two points not in S1 plane in this step
About symmetrical two corresponding points of S1 plane mirror image;By p4 and step (3), remaining point is attached;Above-mentioned established each point
θ value is all 0;
(3.3) equally, in S1 plane, a point is established on the circle that radius is a, is set as p5;In the circle that radius is 2a
On also establish a point;
(3.4) rotary work plane makesIt is 22.5 degree, establishes a point on the circle that radius is 2a;Rotary work is flat
Face makesIt is 45 degree, establishes a point on the circle that radius is a;It resettles and two points not in S1 plane in this step
About symmetrical two points of S1 plane mirror image;P5 and remaining point are attached;The θ value of above-mentioned established each point is all 180;
(4) connection is in the rod piece in hemisphere sideline
(4.1) in S1 plane, the point that a θ value is 0 is established on the circle that radius is a, is set as p6;It is 2a's in radius
The point that a θ value is 22.5 is established on circle;
(4.2) then rotary work plane, makeIt is 22.5 degree, it is 22.5 that a θ value is established on the circle that radius is 2a
Point;Equally, it then does about the symmetrical point of S1 plane mirror image;By p6 and step (4), remaining point is attached;
(5) connection is in the rod piece in hemisphere sideline
(5.1) in S1 plane, the point that a θ value is 180 is established on the circle that radius is a, is set as p7;It is 2a in radius
Circle on establish a θ value be 167.5 point;
(5.2) then rotary work plane, makeIt is 22.5 degree, it is 167.5 that a θ value is established on the circle that radius is 2a
Point;Equally, it then does about the symmetrical point of S1 plane mirror image;By p7 and step (5), remaining point is attached;
(6) S1 plane being rotated 45 degree around z-axis, this plane is S2 plane, step (2)-(5) are repeated, and so on, altogether
It is repeated 3 times;
(7) rod piece of outermost layer hemisphere is connected
The first plane S5 plane for selecting origin first, is initially set to x-y plane;It is on 2a that radius is established in S5 plane
Three adjacent points, each point and center of circle institute are 22.5 degree at central angle, if first point is n1;Change againMakeFor
22.5 degree, it is three points adjacent on 2a that radius is established in S5 plane, and same each point is 22.5 at central angle with center of circle institute
Degree;Equally, identical and symmetrical three points of S1 plane mirror image are resettled;By n1 and step (7), remaining point is attached;If
The θ value of p6 is 180 degree, then θ value is also that the point of 180 degree is not connect with n1 in remaining point;
Then the θ value of n1 being increased by 22.5 degree, then this point is n2, step (2) establishment process is repeated, and so on, weight
It is 6 times multiple;
(8) the remaining rod piece in hemisphere bottom surface is connected
(8.1) in S5 plane, a point is established on the circle that radius is 2a, is set as n8;
(8.2) then rotary work plane, makeIt is 22.5 degree, establishes a point on the circle that radius is 2a;Equally, then
It does about the symmetrical point of S5 plane mirror image;By n8 and step (8), remaining point is attached;The θ of above-mentioned established each point
Value is all 0 degree;
(8.3) equally, working face is re-rotated into S5 plane, establishes a point on the circle that radius is 2a, is set as
n9;
(8.4) then rotary work plane, makeIt is 22.5 degree, establishes a point on the circle that radius is 2a;Equally, then
It does about the symmetrical point of S5 plane mirror image;By n9 and step (8), remaining point is attached;The θ of above-mentioned established each point
Value is all 180 degree;
(9) S5 plane is rotated 22.5 degree around z-axis, sets S6 plane for this plane, (7)-(8) step is repeated, with this
Analogize, is repeated 7 times altogether;
(10) rod piece of innermost layer is connected
Working face is initialized as x-y plane, establishing radius is a, each two points that θ value is 22.5 degree and 45 degree;So
Afterwards around z-axis rotary work plane, makeIt is 45, repeats the foundation of above-mentioned point, be repeated 8 times altogether, by all the points and origin of foundation
It is attached;Finally by x-y plane, θ value is that 90 degree of point is attached with origin.