Disclosure of Invention
The present disclosure provides a prosthesis planning method, a prosthesis planning device, an electronic apparatus, and a storage medium, so as to at least solve the problem in the related art that by manual prosthesis planning, a planner needs to have a lot of experience, and a planner has a high requirement. The technical scheme of the present disclosure is as follows:
According to a first aspect of embodiments of the present disclosure, there is provided a prosthesis planning method comprising: acquiring a medical image and segmenting a local bone map from the medical image, wherein the local bone map comprises a femur bone map and a tibia bone map; identifying osseous mark points in the local skeleton map, marking prosthesis characteristic points on the femoral prosthesis and the tibial prosthesis according to the osseous mark points, and establishing a femoral coordinate system and a tibial coordinate system; and determining the pose and specification of the femoral prosthesis and the tibial prosthesis in the femoral coordinate system and the tibial coordinate system according to the osseous mark points, the prosthesis characteristic points and the target prosthesis angles.
In an exemplary embodiment of the present disclosure, the identifying osseous marker points in the local bone map comprises: identifying a femoral bone map comprising a femoral intercondylar fossa apex, a femoral internal epicondylar point, a femoral external epicondylar point, a femoral head center point, a femoral posterior condylar point, and a femoral anterior condylar apex; identifying the center of the tibial crest, the inner 1/3 point in the tibial tuberosity, the dead point of the tibial posterior fork ligament, the center point of the medial malleolus and the lateral malleolus, the 1/2 point of the tibial crest and the outer diameter point of the tibia in the tibial skeleton diagram.
In an exemplary embodiment of the present disclosure, the labeling of the prosthetic feature points on the femoral prosthesis and the tibial prosthesis according to the osseous landmark includes: marking characteristic points corresponding to the femoral anterior condyle vertex and the femoral posterior condyle point in the femoral skeleton diagram on the femoral prosthesis; and marking characteristic points corresponding to the 1/2 points of the tibial crest and the tibial outer diameter point in the tibial bone map on the tibial prosthesis.
In an exemplary embodiment of the present disclosure, the establishing a femoral coordinate system and a tibial coordinate system includes: establishing the femoral coordinate system according to the femoral intercondylar fossa vertex, the femoral internal epicondylar point, the femoral external epicondylar point and the femoral head center point; and establishing a tibia coordinate system according to the tibia crest center, the inner 1/3 point in the tibia tuberosity, the tibia posterior fork ligament dead point and the inner and outer ankle joint center point.
In one exemplary embodiment of the present disclosure, the establishing the femoral coordinate system according to the femoral intercondylar notch apex, the femoral internal epicondylar point, the femoral external epicondylar point, and the femoral head center point includes: taking the vertex of the intercondylar fossa of the femur as a coordinate origin O of the femur coordinate system, determining an X axis of the femur coordinate system based on the external femoral condyle point and the external femoral condyle point, and determining a Z axis of the femur coordinate system based on the vertex of the intercondylar fossa of the femur and the central point of the femoral head; and determining an X-O-Z plane by a coordinate origin O, X axis and a Z axis, and determining a Y axis by calculating a normal vector of the X-O-Z plane to obtain the femur coordinate system.
In one exemplary embodiment of the present disclosure, the establishing the tibial coordinate system in terms of the tibial crest center, the medial 1/3 point in the tibial tuberosity, the tibial posterior fork ligament dead center, and the medial and lateral ankle joint center point includes: taking the center of the tibial crest as a coordinate origin O of the tibial coordinate system, and calculating a center point of the center points of the inner ankle joint and the outer ankle joint; determining a Z axis of the tibial coordinate system according to the central point of the central points of the inner ankle joint and the outer ankle joint and the center of the tibial crest, and determining a Y axis of the tibial coordinate system according to the 1/3 point in the tibial tuberosity and the dead point of the tibial posterior fork ligament; and determining a Y-O-Z plane based on the coordinate origin O, Z axis and the Y axis, and obtaining an X axis by calculating a normal vector of the Y-O-Z plane to obtain the tibia coordinate system.
In an exemplary embodiment of the present disclosure, the determining, in the femoral coordinate system, the pose and the specification of the femoral prosthesis according to the osseous landmark point, the prosthesis feature point, and the target prosthesis angle includes: in the femur coordinate system, determining a parameter transformation matrix corresponding to the femur prosthesis according to the ossification mark points, the prosthesis feature points and the target prosthesis angles of the femur, so as to determine the pose of the femur prosthesis according to the parameter transformation matrix; and determining the specification of the femoral prosthesis according to the distance between the femoral anterior condyle point and the femoral posterior condyle point and the distance between the femoral anterior condyle point and the corresponding prosthesis characteristic point of the femoral posterior condyle point in the femoral prosthesis.
In an exemplary embodiment of the present disclosure, the determining the pose and the specification of the tibial prosthesis according to the osseous landmark points, the prosthesis feature points, and the target prosthesis angle in the tibial coordinate system includes: in the tibia coordinate system, determining a parameter transformation matrix corresponding to the tibia prosthesis according to the ossification mark points, the prosthesis characteristic points and the target prosthesis angles of the tibia, so as to determine the pose of the tibia prosthesis according to the parameter transformation matrix; and determining the specification of the tibial prosthesis according to the distance between the 1/2 point of the tibial crest and the tibial outer diameter point and the distance between the 1/2 point of the tibial crest and the corresponding characteristic point of the prosthesis of the tibial outer diameter point in the tibial prosthesis.
According to a second aspect of embodiments of the present disclosure, there is provided a prosthesis planning apparatus comprising: a bone map acquisition module configured to perform acquiring a medical image and to segment a local bone map from the medical image, the local bone map comprising a femoral bone map and a tibial bone map; the coordinate system establishing module is configured to identify osseous mark points in the local skeleton map, mark prosthesis characteristic points on the femoral prosthesis and the tibial prosthesis according to the osseous mark points, and establish a femoral coordinate system and a tibial coordinate system; and the prosthesis planning module is configured to be executed in the femur coordinate system and the tibia coordinate system, and the pose and the specification of the femur prosthesis and the tibia prosthesis are determined according to the osseous mark points, the prosthesis characteristic points and the target prosthesis angles.
According to a third aspect of embodiments of the present disclosure, there is provided an electronic device, comprising: a processor; and a memory for storing the processor-executable instructions; wherein the processor is configured to execute the instructions to implement the method of any one of the above.
According to a fourth aspect of embodiments of the present disclosure, there is provided a storage medium, which when executed by a processor of an electronic device, enables the electronic device to perform the method of any one of the above.
According to a fifth aspect of embodiments of the present disclosure, there is provided a computer program product, which when executed by a processor, implements the method of any of the above.
The technical scheme provided by the embodiment of the disclosure at least brings the following beneficial effects:
In the prosthesis planning method provided by the embodiment of the disclosure, a medical image is acquired, and a local skeleton map is segmented from the medical image, wherein the local skeleton map comprises femur and tibia; identifying osseous mark points in the local skeleton map, marking prosthesis characteristic points on the femoral prosthesis and the tibial prosthesis according to the osseous mark points, and establishing a femoral coordinate system and a tibial coordinate system; in the femur coordinate system and the tibia coordinate system, the pose and specification of the femur prosthesis and the tibia prosthesis are determined according to the osseous mark points, the prosthesis characteristic points and the target prosthesis angles. The method and the device can accurately and rapidly realize automatic planning of the pose and model of the prosthesis by establishing the femur and tibia coordinate systems and determining the pose and the specification of the femur prosthesis and the tibia prosthesis in the established coordinate systems.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the present disclosure. One skilled in the relevant art will recognize, however, that the aspects of the disclosure may be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the present disclosure.
Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software or in one or more hardware modules or integrated circuits or in different networks and/or processor devices and/or microcontroller devices.
In a knee unicondylar replacement surgical robot, a reasonable prosthetic preoperative plan can effectively restore the patient's lower limb force lines, thereby better guiding the physician to perform prosthetic installation during surgery. However, manual prosthesis planning requires a great deal of experience for the planner, and requires a high level of skill on the planner.
In order to achieve automatic prosthesis planning with high accuracy, the present disclosure provides a prosthesis planning method, a prosthesis planning device, an electronic apparatus, and a storage medium. The present disclosure is described in detail below with reference to specific examples.
Fig. 1 is a flow chart illustrating a method of prosthesis planning, as shown in fig. 1, according to an exemplary embodiment, the method of prosthesis planning comprising the steps of:
S110: acquiring a medical image and segmenting a local bone map from the medical image, wherein the local bone map comprises a femur bone map and a tibia bone map;
S120: identifying osseous mark points in the local skeleton map, marking prosthesis characteristic points on the femoral prosthesis and the tibial prosthesis according to the osseous mark points, and establishing a femoral coordinate system and a tibial coordinate system;
s130: in the femur coordinate system and the tibia coordinate system, the pose and specification of the femur prosthesis and the tibia prosthesis are determined according to the osseous mark points, the prosthesis characteristic points and the target prosthesis angles.
The method and the device can accurately and rapidly realize automatic planning of the pose and model of the prosthesis by establishing the femur and tibia coordinate systems and determining the pose and the specification of the femur prosthesis and the tibia prosthesis in the established coordinate systems.
The following describes each step in the above-mentioned prosthesis planning method, specifically, the above-mentioned prosthesis planning method includes:
in step S110, a medical image is acquired, and a local bone map including a femur bone map and a tibia bone map is segmented from the medical image.
Medical imaging refers to techniques and procedures for non-invasively acquiring an image of internal tissue of a human body or a portion of a human body for medical or medical research. The medical image may be an image obtained by the medical imaging technique, for example, a CT image. In an embodiment of the present disclosure, the step is used to acquire a medical image and to segment a local bone map from the medical image. For example, a patient may be imaged with CT images of the hip, knee, and ankle. And segmenting a local bone map from the CT image, the local bone map being a three-dimensional image containing the femur and tibia for subsequent prosthesis planning.
In step S120, bone mark points are identified in the local skeleton map, and the feature points of the prosthesis are marked on the femoral prosthesis and the tibial prosthesis according to the bone mark points, and a femoral coordinate system and a tibial coordinate system are established.
The bone mark points are bones of certain parts of a human body, often form obvious bulges or depressions on the body surface of the human body, and are often used for positioning in clinic and the like. In the embodiment of the present disclosure, after the local bone map is obtained in the step S110, the bone landmark is identified in the local bone map, and illustratively, the bone landmark may be automatically identified in the local bone map by a machine learning method.
Taking the above local bone map as a femur bone map as an example, the local bone map automatically identifies and marks the bone mark points, specifically, as shown in fig. 2, the bone mark points may include: the intercondylar notch apex pf1, the medial femoral epicondylar point pf2, the lateral femoral epicondylar point pf3, the femoral head center point pf4, the posterior femoral condyle point pf5 (the lowest femoral point when the femur is flexed 90 degrees), and the anterior femoral condyle apex pf6 are identified and labeled in the femoral bone map as described above with reference to fig. 2.
Taking the above local bone map as an example of a tibial bone map, the local bone map automatically identifies and marks the bone mark points, specifically, as shown in fig. 3, the bone mark points may include: the center of the tibia crest pt1, the inner 1/3 point pt2 in the tibia tuberosity, the dead point pt3 of the tibial posterior fork ligament, the center point pt4、pt5 of the medial malleolus and the lateral malleolus, the 1/2 point pt6 of the tibia crest and the outer diameter point pt7 of the tibia are identified and marked in a tibia skeleton map as shown in figure 3.
After identifying the bone mark points in the femur skeleton diagram and the tibia skeleton diagram, marking the prosthesis characteristic points on the femur prosthesis and the tibia prosthesis according to the bone mark points, and establishing a femur coordinate system and a tibia coordinate system. Illustratively, the marking of the prosthetic feature points on the femoral and tibial prostheses according to the bony landmark points described above may be accomplished as follows: marking a characteristic point corresponding to a femoral anterior condyle point and a femoral posterior condyle point in a femoral skeleton diagram on the femoral prosthesis; feature points corresponding to the 1/2 points of the tibial crest and the outer diameter point of the tibia in the tibial bone map are marked on the tibial prosthesis.
Specifically, taking the femoral bone map shown in fig. 2 as an example, the femoral posterior condyle point pf5 is selected as a point B and the femoral anterior condyle vertex pf6 is selected as a point a in the femoral bone map, as shown in fig. 4. Then, in the femoral prosthesis shown in fig. 5, a feature point pp1 corresponding to the femoral anterior condyle apex pf6 is designated as a point C, and a feature point pp2 corresponding to the femoral posterior condyle point pf5 is designated as a point D.
Taking the tibial bone map shown in fig. 3 as an example, the tibial crest 1/2 point pt6 is selected as a point E and the tibial outer diameter point pt7 is selected as a point F in the tibial bone map, as shown in fig. 6. Then, in the tibial prosthesis shown in fig. 7, a feature point pp3 corresponding to the tibial crest 1/2 point pt6 is designated as a point G, and a feature point pp4 corresponding to the tibial outer diameter point pt7 is designated as a point H.
The above process of establishing the femoral coordinate system and the tibial coordinate system can be implemented as follows: establishing a femoral coordinate system according to the femoral intercondylar fossa vertex, the femoral internal epicondylar point, the femoral external epicondylar point and the femoral head center point; and establishing a tibia coordinate system according to the center of the tibia crest, the 1/3 point in the tibia tuberosity, the dead point of the tibia posterior fork ligament and the center point of the internal ankle joint and the external ankle joint.
The establishment of the femoral coordinate system according to the femoral intercondylar fossa vertex, the femoral internal epicondylar point, the femoral external epicondylar point and the femoral head center point can be realized as follows: taking the vertex of the intercondylar fossa of the femur as a coordinate origin O of a femur coordinate system, determining an X-axis of the femur coordinate system based on the vertex of the intercondylar fossa of the femur and the external epicondylar point of the femur, and determining a Z-axis of the femur coordinate system based on the vertex of the intercondylar fossa of the femur and the central point of the femoral head; and determining an X-O-Z plane by a coordinate origin O, X axis and a Z axis, and determining a Y axis by calculating a normal vector of the X-O-Z plane to obtain a femur coordinate system.
Taking the above femur skeleton diagram shown in fig. 2 as an example, the osseous mark point pf1-pf4 in fig. 2 is used for establishing a femur coordinate system, and the femur coordinate system is established specifically as follows: taking the femoral intercondylar notch vertex pf1 as a coordinate origin Of of a femoral coordinate system, namely the coordinate origin O of the femoral coordinate system; determining the Xf axis of a femoral coordinate system based on the femoral inner epicondylar point pf2 and the femoral outer epicondylar point pf3, namely the X axis of the femoral coordinate system; determining a Zf axis of a femoral coordinate system based on a femoral intercondylar fossa vertex pp1 and a femoral head center point pp4, namely the Z axis of the femoral coordinate system; according to the determined coordinate origin Of、Xf axis and Zf axis, an Xf-Of-Zf plane of a femur coordinate system, namely an X-O-Z plane of the femur coordinate system, can be obtained; the Yf axis of the femoral coordinate system is determined by calculating the normal vector of the Xf-Of-Zf plane, that is, the Y axis of the above femoral coordinate system, to obtain the femoral coordinate system, and the obtained femoral coordinate system is established as shown in fig. 2.
Preferably, since the Xf axis of the femoral coordinate system obtained through the above procedure is not necessarily perpendicular to the Zf axis, the embodiments of the present disclosure may also correct the Zf axis, and the specific correction procedure may be implemented as: and calculating the normal vector of the Xf-Of-Yf plane, and taking the calculated normal vector as the Zf axis.
The establishment of the tibial coordinate system according to the center of the tibial crest, the inner 1/3 point in the tibial tuberosity, the dead point of the tibial posterior fork ligament and the center point of the inner ankle joint and the outer ankle joint can be realized as follows: taking the center of the tibial crest as a coordinate origin O of a tibial coordinate system, and calculating a center point of the inner ankle joint and a center point of the outer ankle joint; determining a Z axis of a tibia coordinate system according to a central point of the central points of the inner ankle joint and the outer ankle joint and the center of the tibial crest, and determining a Y axis of the tibia coordinate system according to 1/3 points in the tibial tuberosity and a tibial posterior fork ligament dead point; and determining a Y-O-Z plane based on the coordinate origin O, Z axis and the Y axis, and calculating the normal vector of the Y-O-Z plane to obtain an X axis, thereby obtaining a tibia coordinate system.
Taking the tibial bone map shown in fig. 3 as an example, the osseous mark point pt1-pt5 in fig. 3 is used for establishing a tibial coordinate system, and the establishment process of the tibial coordinate system is specifically as follows: taking the center pt1 of the tibial crest as the origin of coordinates Ot of the tibial coordinate system, namely the origin of coordinates O of the tibial coordinate system; calculating a center point pC of the medial-lateral ankle center point pt4、pt5, and determining a Zt axis, namely a Z axis of the tibial coordinate system, according to the center point pC and a tibial crest center pt1; determining a Yt axis of a tibial coordinate system according to an inner 1/3 point pt2 in the tibial tuberosity and a tibial posterior fork ligament dead point pt3, namely a Y axis of the tibial coordinate system, and determining a Yt-Ot-Zt plane of the tibial coordinate system by an origin Ot、Zt axis and a Yt axis; the Xt axis of the tibial coordinate system, namely the X axis of the tibial coordinate system, is determined by calculating the normal vector of the Yt-Ot-Zt plane, so as to obtain the tibial coordinate system, and the obtained tibial coordinate system is established as shown in figure 3.
Preferably, since the Yt axis and the Zt axis of the tibial coordinate system obtained through the above procedure are not necessarily perpendicular, the embodiments of the present disclosure can also correct the Yt axis, and the specific correction procedure can be implemented as follows: and calculating the normal vector of the Xt-Ot-Zt plane, and correcting by taking the calculated normal vector as the Yt axis.
In step S130, the pose and specification of the femoral prosthesis and the tibial prosthesis are determined according to the osseous landmark points, the prosthesis feature points, and the target prosthesis angle in the femoral coordinate system and the tibial coordinate system.
After identifying the osseous mark points in the steps S110 and S120, marking the corresponding prosthetic feature points in the femoral prosthesis and the tibial prosthesis, and establishing the femoral coordinate system and the tibial coordinate system, the prosthetic planning method provided by the embodiment of the disclosure performs prosthetic planning in the established femoral coordinate system and tibial coordinate system, and the prosthetic planning mainly includes determining the pose and specification of the femoral prosthesis and the tibial prosthesis.
In the femoral coordinate system, the pose and specification of the femoral prosthesis are determined according to the osseous mark points, the prosthesis feature points and the target prosthesis angle, and the method can be realized as follows: in a femur coordinate system, determining a parameter transformation matrix corresponding to the femur prosthesis according to the bone mark points of the femur, the prosthesis feature points and the target prosthesis angles, so as to determine the pose of the femur prosthesis according to the parameter transformation matrix; and determining the specification of the femoral prosthesis according to the distance between the femoral anterior condyle point and the femoral posterior condyle point and the distance between the femoral anterior condyle point and the corresponding prosthesis characteristic point of the femoral posterior condyle point in the femoral prosthesis.
Taking the above-mentioned femur skeleton diagram shown in fig. 2 as an example, specifically, the above-mentioned determination of the pose of the femoral prosthesis may be implemented as follows: let the femur prosthesis F get the planned pose through the rigid transformation matrix Mf as shown in the following formula:
Wherein,And p is the point on the femoral prosthesis, and p, is the point transformed by the parameter transformation matrix. In the parametric transformation matrix, af is a rotation matrix, Bf is a translation matrix,
Wherein, αf、βf、γf is the rotation angle around the X axis, Y axis and Z axis, and bf0、bf1、bf2 is the translation amount along the X axis, Y axis and Z axis.
The transformation parameters (bf0、bf1、bf2,αf、βf、γf) in the above femoral prosthesis transformation procedure are solved as follows, for which the known conditions are:
(1) Assume that the initial pose of the prosthesis in the femoral prosthesis library is: inside and outside turning angle 0 degree, inside and outside rotation angle 0 degree, buckling and stretching angle 0 degree;
(2) The rotation angles of the femur coordinate system established according to the osseous mark points relative to the world coordinate system are respectively thetafx、θfy、θfz;
(3) The prosthesis is planned to be in the inside-out turning angle, the inside-out rotation angle, buckling and stretching in the femur coordinate system;
(4) Feature point pp1(xp1,yp1,zp1) on the planned prosthesis should be 1.5mm directly above femoral intercondylar notch vertex pf4(xf4,yf4,zf4), i.e., point pf6, which is mapped to the femoral coordinate system after point pp1 has passed through transformation matrix Mf, should be 1.5mm directly above pf4, as shown in fig. 2. Wherein, 1.5mm is an empirical value.
(5) The planned femoral prosthesis centerline plane passes through the femoral posterior condyle centerline point pf5(xf5,yf5,zf5) and point pf6(xf6,yf6,zf6).
According to the above known conditions (1) to (3), femur rotation angles of θfx、θfy、θfz, that is, αf＝θfx、βf＝θfy、γf＝θfz, respectively, can be obtained; the coordinates (xf6,yf6,zf6) of pf6 are (xf5,yf4-1.5,zf6) according to the known conditions (4) and (5), and since xf5 and yf4 are known, zf6 is unknown, and (xf5,yf4-1.5,zf6) is a straight line; the value of zf6, and thus the coordinates of pf6, is determined by solving for the nearest point on the straight line (xf5,yf4-1.5,zf6) on the femoral surface.
As shown in the femur skeleton diagram shown in fig. 4 and the femur prosthesis diagram shown in fig. 5, the above-described specification of the femur prosthesis is determined by dAB in fig. 4 and dCD in fig. 5. Wherein dAB is the projection length of a line segment AB formed by the anterior femoral condyle apex pf6 and the posterior femoral condyle point pf5 on the Z axis; dCD is the projected length of a segment CD on the Z axis, which is formed by the prosthetic feature point pp1 corresponding to the femoral anterior condyle apex pf6 and the prosthetic feature point pp2 corresponding to the femoral posterior condyle point pf5 in the femoral prosthesis. Specifically, assuming that the femoral prostheses in the prosthesis library have n model sizes, the dCD values thereof are (dCD1,dCD2,…,dCDn) from small to large, comparing dAB with the model sizes one by one, and selecting the model number corresponding to the last dCD value smaller than or equal to dAB as the determined prosthesis specification.
Wherein, in the tibia coordinate system, the pose and specification of the tibia prosthesis are determined according to the osseous mark points, the prosthesis feature points and the target prosthesis angles, comprising: in a tibia coordinate system, determining a parameter transformation matrix corresponding to the tibia prosthesis according to the bone mark points of the tibia, the prosthesis feature points and the target prosthesis angles, so as to determine the pose of the tibia prosthesis according to the parameter transformation matrix; and determining the specification of the tibial prosthesis according to the distance between the 1/2 point of the tibial crest and the external diameter point of the tibia and the distance between the 1/2 point of the tibial crest and the corresponding characteristic point of the prosthesis in the tibial prosthesis.
Taking the tibial bone map shown in fig. 3 as an example, specifically, the above-mentioned determination of the pose of the tibial prosthesis may be implemented as follows: the tibial prosthesis T is set to obtain the planned pose through the rigid transformation matrix Mt, and the following formula is shown:
Wherein,And p is the point on the tibial prosthesis, and p, is the point transformed by the parameter transformation matrix. In the parametric transformation matrix, at is a rotation matrix, Bt is a translation matrix,
Alphat、βt、γt is the rotation angle around the X axis, Y axis and Z axis, and bt0、bt1、bt2 is the translation amount along the X axis, Y axis and Z axis.
The following is a solution to the transformation parameters (bt0、bt1、bt2,αt、βt、γt) in the above tibial prosthesis transformation procedure, for which the known conditions are:
(1) Assume that the initial pose of the prosthesis in the tibial prosthesis library is: inside-out angle 0 degree, inside-out rotation angle 0 degree and front-back inclination angle 5 degrees;
(2) The rotation angles of the tibia coordinate system established according to the osseous mark points relative to the world coordinate system are respectively thetatx、θty、θtz;
(3) The feature point pp5(xp5,yp5,zp5) on the tibial prosthesis corresponds to the tibial ossification mark point pt6(xt6,yt6,zt6) after passing through the transformation matrix Mt.
According to the known conditions (1) and (2), the rotation angles of the tibia are respectively thetatx、θty、θtz, namely alphat＝θtx+5°、βt＝θty、γt＝θtz, and the rotation matrix At is determined; the translation matrix Bt is determined based on the known conditions (3),At*(xt6,yt6,zt6,1)T+Bt＝(xt6,yt6,zt6,1)T,.
As shown in the tibial bone map of fig. 6 and the tibia of fig. 7, the above-described determination of the tibial prosthesis specification is determined by dEF in fig. 6 and dGH in fig. 7. Wherein dEF is the projection length of a line segment EF formed by a tibia crest 1/2 point pt6 and a tibia outer diameter point pt7 on the X axis, and dGH is the projection length of a line segment GH formed by a prosthesis characteristic point pp5 corresponding to the tibia crest 1/2 point and a prosthesis characteristic point pp6 corresponding to the tibia outer diameter point on the tibia prosthesis on the X axis. Specifically, assuming that the tibial prostheses in the prosthesis library have n model sizes, the dGH values thereof are (dGH1,dGH2,…,dGHn) from small to large, comparing dEF with the model sizes one by one, and selecting the model number corresponding to the dHH value which is greater than or equal to dEF as the determined prosthesis specification.
It should be noted that although the steps of the methods in the present disclosure are depicted in the accompanying drawings in a particular order, this does not require or imply that the steps must be performed in that particular order, or that all illustrated steps be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step to perform, and/or one step decomposed into multiple steps to perform, etc.
Correspondingly, the embodiment of the disclosure also provides a block diagram of the prosthesis planning device. As shown in fig. 8, the apparatus includes a bone map acquisition module 810, a coordinate system creation module 820, and a prosthesis planning module 830. Wherein:
A bone map acquisition module 810 configured to perform acquiring a medical image and to segment a local bone map from the medical image, the local bone map comprising a femoral bone map and a tibial bone map;
A coordinate system creation module 820 configured to perform identification of bone landmark points in the local bone map, labeling prosthetic feature points on the femoral prosthesis and the tibial prosthesis according to the bone landmark points, and creating a femoral coordinate system and a tibial coordinate system;
the prosthesis planning module 830 is configured to determine the pose and specification of the femoral and tibial prostheses from the bony landmark points, the prosthetic feature points, the target prosthetic angles, as performed in the femoral and tibial coordinate systems.
In an exemplary embodiment of the present disclosure, the coordinate system creation module 820 specifically implements the identification of bony landmark points in the local bone map by: identifying a femoral bone map comprising a femoral intercondylar fossa apex, a femoral internal epicondylar point, a femoral external epicondylar point, a femoral head center point, a femoral posterior condylar point, and a femoral anterior condylar apex; identifying the center of the tibial crest, the inner 1/3 point in the tibial tuberosity, the dead point of the tibial posterior fork ligament, the center point of the medial malleolus and the lateral malleolus, the 1/2 point of the tibial crest and the outer diameter point of the tibia in the tibial skeleton diagram.
In an exemplary embodiment of the present disclosure, the coordinate system creation module 820 specifically implements the labeling of the prosthetic feature points on the femoral prosthesis and the tibial prosthesis according to the bone-based landmark by: marking a characteristic point corresponding to a femoral anterior condyle point and a femoral posterior condyle point in a femoral skeleton diagram on the femoral prosthesis; feature points corresponding to the 1/2 points of the tibial crest and the outer diameter point of the tibia in the tibial bone map are marked on the tibial prosthesis.
In an exemplary embodiment of the present disclosure, the coordinate system establishment module 820 specifically implements the establishment of the femur coordinate system and the tibia coordinate system through the following procedures: establishing a femoral coordinate system according to the femoral intercondylar fossa vertex, the femoral internal epicondylar point, the femoral external epicondylar point and the femoral head center point; and establishing a tibia coordinate system according to the center of the tibia crest, the 1/3 point in the tibia tuberosity, the dead point of the tibia posterior fork ligament and the center point of the internal ankle joint and the external ankle joint.
Specifically, the above-mentioned process of establishing the femoral coordinate system according to the femoral intercondylar notch apex, the femoral internal epicondylar point, the femoral external epicondylar point, and the femoral head center point can be implemented as follows: taking the vertex of the intercondylar fossa of the femur as a coordinate origin O of a femur coordinate system, determining an X axis of the femur coordinate system based on the internal femoral epicondylar point and the external femoral epicondylar point, and determining a Z axis of the femur coordinate system based on the vertex of the intercondylar fossa of the femur and the central point of the femoral head; and determining an X-O-Z plane by a coordinate origin O, X axis and a Z axis, and determining a Y axis by calculating a normal vector of the X-O-Z plane to obtain a femur coordinate system.
The implementation process for establishing the tibia coordinate system according to the tibia crest center, the inner 1/3 point in the tibia tuberosity, the tibia posterior fork ligament dead point and the inner ankle joint center point can be as follows: taking the center of the tibial crest as a coordinate origin O of a tibial coordinate system, and calculating a center point of the inner ankle joint and a center point of the outer ankle joint; determining a Z axis of a tibia coordinate system according to a central point of the central points of the inner ankle joint and the outer ankle joint and the center of the tibial crest, and determining a Y axis of the tibia coordinate system according to 1/3 points in the tibial tuberosity and a tibial posterior fork ligament dead point; and determining a Y-O-Z plane based on the coordinate origin O, Z axis and the Y axis, and calculating the normal vector of the Y-O-Z plane to obtain an X axis, thereby obtaining a tibia coordinate system.
The prosthesis planning module 830 may specifically determine the pose and specification of the femoral prosthesis in the femoral coordinate system according to the osseous landmark, the prosthesis feature point and the target prosthesis angle by the following procedures: in a femur coordinate system, determining a parameter transformation matrix corresponding to the femur prosthesis according to the bone mark points of the femur, the prosthesis feature points and the target prosthesis angles, and determining the pose of the femur prosthesis according to the parameter transformation matrix; and determining the specification of the femoral prosthesis according to the distance between the femoral anterior condyle point and the femoral posterior condyle point and the distance between the femoral anterior condyle point and the corresponding prosthesis characteristic point of the femoral posterior condyle point in the femoral prosthesis.
The prosthesis planning module 830 may specifically determine the pose and specification of the tibial prosthesis in the tibial coordinate system according to the osseous landmark points, the prosthesis feature points and the target prosthesis angle by the following procedures, including: in a tibia coordinate system, determining a parameter transformation matrix corresponding to the tibia prosthesis according to the bone mark points of the tibia, the prosthesis feature points and the target prosthesis angles, and determining the pose of the tibia prosthesis according to the parameter transformation matrix; and determining the specification of the tibial prosthesis according to the distance between the 1/2 point of the tibial crest and the external diameter point of the tibia and the distance between the 1/2 point of the tibial crest and the corresponding characteristic point of the prosthesis in the tibial prosthesis.
The specific manner in which the individual units or modules perform the operations in the apparatus of the above embodiments has been described in detail in relation to the embodiments of the method, and will not be described in detail here.
It should be noted that although in the above detailed description several modules or units of a device for action execution are mentioned, such a division is not mandatory. Indeed, the features and functionality of two or more modules or units described above may be embodied in one module or unit in accordance with embodiments of the present disclosure. Conversely, the features and functions of one module or unit described above may be further divided into a plurality of modules or units to be embodied.
Fig. 9 shows a schematic diagram of a computer system suitable for use in implementing embodiments of the present disclosure.
It should be noted that, the computer system 900 of the electronic device shown in fig. 9 is only an example, and should not impose any limitation on the functions and the application scope of the embodiments of the present disclosure.
As shown in fig. 9, the computer system 900 includes a Central Processing Unit (CPU) 901, which can execute various appropriate actions and processes according to a program stored in a Read Only Memory (ROM) 902 or a program loaded from a storage section 908 into a Random Access Memory (RAM) 903. In the RAM 903, various programs and data required for system operation are also stored. The CPU901, ROM 902, and RAM 903 are connected to each other through a bus 904. An input/output (I/O) interface 905 is also connected to the bus 904.
The following components are connected to the I/O interface 905: an input section 906 including a keyboard, a mouse, and the like; an output portion 907 including a display such as a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), and a speaker; a storage portion 908 including a hard disk or the like; and a communication section 909 including a network interface card such as a LAN card, a modem, or the like. The communication section 909 performs communication processing via a network such as the internet. The drive 910 is also connected to the I/O interface 905 as needed. A removable medium 911 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is installed as needed on the drive 910 so that a computer program read out therefrom is installed into the storage section 908 as needed.
As another aspect, the present application also provides a computer-readable medium that may be contained in the electronic device described in the above embodiment; or may exist alone without being incorporated into the electronic device. The computer-readable medium carries one or more programs which, when executed by one of the electronic devices, cause the electronic device to implement the method as in the embodiments.
It should be noted that the computer readable medium shown in the present disclosure may be a computer readable signal medium or a computer readable storage medium, or any combination of the two. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this disclosure, a computer-readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. In the present disclosure, however, the computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, with the computer-readable program code embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, fiber optic cable, RF, etc., or any suitable combination of the foregoing.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.