WO2019237513A2 - 基于六轴并联骨外固定装置的骨折康复评价方法 - Google Patents

基于六轴并联骨外固定装置的骨折康复评价方法 Download PDF

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WO2019237513A2
WO2019237513A2 PCT/CN2018/102721 CN2018102721W WO2019237513A2 WO 2019237513 A2 WO2019237513 A2 WO 2019237513A2 CN 2018102721 W CN2018102721 W CN 2018102721W WO 2019237513 A2 WO2019237513 A2 WO 2019237513A2
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fracture
axial
force
branch
rehabilitation
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PCT/CN2018/102721
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English (en)
French (fr)
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孙涛
刘思达
宋轶民
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天津大学
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
    • A61B17/60—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like for external osteosynthesis, e.g. distractors, contractors
    • A61B17/62—Ring frames, i.e. devices extending around the bones to be positioned

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  • the invention relates to the technical field of orthopedic external fixation, in particular to a method for fixing a fracture using a six-axis parallel bone external fixation device and quantitatively evaluating the rehabilitation status of the fracture.
  • the orthopedic external fixation technique is a six-axis parallel bone external fixation device that fixes the fracture end and provides a suitable mechanical environment for fracture healing.
  • Patents US6030386, US8439914 and patent WO2011163406 propose a type of six-axis parallel bone external fixation device. This type of device consists of six branch chains with exactly the same topology and two fixing rings. The doctor uses a metal bone needle to fix the two fixing rings to the bone pieces at both ends of the patient's fracture. Six branches are connected to the two fixing rings through hinges at both ends. Adjusting the length of the six branches in accordance with the rules can generate six-degree-of-freedom relative movements of the two fixed rings to accurately correct the spatial deformity of the fracture and achieve fracture reduction.
  • the length of the branch chain is maintained and the six-axis parallel external fixation
  • the device maintains relatively stable fracture ends.
  • This type of six-axis parallel bone external fixation device has both the functions of reduction and fixation of fractured ends, and has broad application prospects.
  • the existing evaluation methods for fracture rehabilitation are mainly divided into qualitative evaluation (for example, activity observation method, X-ray image observation method and ultrasonic image observation method, etc.) and quantitative evaluation (for example, bone load measurement method and epiphyseal stiffness estimation method). class.
  • patents US5873843 and US5437668 propose a method for assessing the state of rehabilitation using the load on the bone, which mainly includes: removing the original fixation of the external fixation device of the original fracture along the axis of the bone axis, and replacing it with one or more columnar forces
  • the detection device forms the state of sharing the axial load of the limb in parallel with the bone; measures the total load carried by the patient's limb, subtracts the load from the device feedback from the force sensing device, and calculates the load carried by the bone; the bone bears the load and the limb bears the total load
  • the ratio is an indicator, which reflects the carrying capacity of the bones and evaluates the rehabilitation effect.
  • Patents US5697165, EP1217960 and US20130041288 propose a method for evaluating fracture rehabilitation based on epiphyseal stiffness, which mainly includes: removing the external fixation device of the original fixed fracture along the axis of the bone axis, on the side of the affected limb close to the fracture site, Install a device that can detect plane / spatial deformation; apply a certain amount of load to the affected limb to measure the relative deformation of the fracture end; use the load-deformation relationship to calculate the stiffness of the epiphyseal tissue and use this as an index to evaluate the fracture The effect of rehabilitation.
  • the purpose of the present invention is to overcome the shortcomings of the prior art and provide a fracture rehabilitation evaluation method based on a six-axis parallel bone external fixation device that can accurately detect a patient's fracture rehabilitation status for a long time without causing secondary trauma.
  • the fracture rehabilitation evaluation method based on the six-axis parallel bone external fixation device of the present invention includes the following steps:
  • Step 1 Modify the six-axis parallel bone external fixation device:
  • a six-axis parallel bone external fixation device including a proximal fixing ring, a distal fixing ring, and a first branch chain, a first branch, and a first branch chain to be connected between the proximal fixing ring and the distal fixing ring.
  • Two branches, a third branch, a fourth branch, a fifth branch and a sixth branch, each branch is composed of a first Hook hinge at the upper end of the branch, a driving screw in the middle of the branch and the lower end of the branch
  • the second Hook hinge is formed;
  • the six branches of the six-axis parallel bone external fixation device are equipped with tension pressure sensors by the method of: splitting the first Hook hinge and the driving screw of the first to sixth branches, An axial force sensor is coaxially fixed between the two;
  • Step 2 Adjust the six-axis parallel bone external fixation device to reduce fracture deformity.
  • the steps are: obtain the six-axis parallel bone external fixation device adjustment plan required to reduce the fracture deformity, and adjust the length of the six branch chains according to the adjustment plan. Reduction of fracture malformation; After completing fracture reduction, lock the length of the six branches and fix the fracture site;
  • Step 3 Identify the spatial location of the marker and fracture bone:
  • the first marker, the second marker, and the third marker are evenly spaced in the circumferential direction;
  • the fourth marker, the fifth marker, and the sixth marker are evenly spaced in the circumferential direction;
  • the first to sixth markers have the same structure, and each includes a marker sphere and a connecting pin;
  • the marker is fixedly connected by inserting the shaft body at the lower end of the pin into the inner ring connection hole of the proximal fixing ring or the distal fixing ring;
  • the marking sphere is made of metal material, and the marker pin is made of plastic material;
  • Step 4 According to the fracture rehabilitation stage division method commonly used in the clinical field, the rehabilitation stage is divided into three stages: hematoma mechanization stage, primitive epiphyseal stage, and epiphyseal reconstruction stage based on bone tissue growth.
  • the hematoma mechanization period and the original callus period are referred to as a first period, and the callus reconstruction period is referred to as a second period;
  • Step 5 When the patient's fracture rehabilitation is in the first stage, follow the steps below to fine-tune the six-axis parallel bone external fixation device and guide the patient in rehabilitation training:
  • the computer system uses a spherical fitting algorithm to automatically identify the six spherical center coordinates of the first three-dimensional sphere to the sixth three-dimensional sphere; using a spatial geometric algorithm, the first The coordinates of the center of a three-dimensional sphere, the second three-dimensional sphere, and the third three-dimensional sphere. Identify the plane Puv that coincides with the upper surface of the proximal fixing ring. Use the geometric center point of the upper surface of the proximal fixing ring as the origin P of the coordinate system.
  • the vector formed by the projection point of the first three-dimensional sphere sphere center on the plane Puv is the coordinate axis Take the vector passing through point P and parallel to the direction of the plane Puv normal vector as the coordinate axis
  • a proximal coordinate system P-uvw fixedly connected to the proximal fixing ring is established; the center coordinates of the fourth three-dimensional sphere, the fifth three-dimensional sphere, and the sixth three-dimensional sphere are identified to coincide with the upper surface of the distal fixed ring.
  • the plane Oxy takes the geometric center point of the upper surface of the distal fixing ring as the origin O of the coordinate system, and the vector formed by the origin point through the projection point of the fourth three-dimensional sphere center on the plane Oxy as the coordinate axis Take the vector passing through point O and parallel to the direction of the plane Oxy normal vector as the coordinate axis
  • a remote coordinate system O-xyz fixedly connected to the distal fixation ring according to the right-hand rule; use the coordinate system P-uvw and coordinate system O-xyz to determine the spatial position and attitude of the six-axis parallel bone external fixation device;
  • ⁇ pr represents the pretension force spiral Of the force couple component.
  • the linear force component f pr of the pretensioned linear force spiral is decomposed along the direction of the backbone axis specified in step 3 to obtain the axial axial pretension force F f, pr , and the pretension force couple ⁇ pr is oriented in a direction perpendicular to the backbone axis Decompose to obtain the lateral preloading bending moment M f, pr of the backbone;
  • the computer system uses a graphical software interface to display the three-dimensional image stored in the computer system in step three, and the operator specifies the transverse direction of the backbone near the fracture section in the graphical software interface.
  • the computer system uses a graphics intersection algorithm to automatically identify the annular graphic area corresponding to the cortical bone at the designated backbone cross section, and then calculate the bearing area S b of the fracture end corresponding to the annular graphic area;
  • the computer system calculates the axial compressive stress ⁇ b of the fracture section and the lateral preloading bending moment M f, pr of the fracture, respectively. Comparing the allowable axial compressive stress ⁇ e and the allowable lateral bending load M e provided by the above-mentioned knowledge base, if the ratio of the axial compressive stress ⁇ b to the allowable axial compressive stress ⁇ e of the fractured section of the patient is 60% ⁇ in the range of 120%, and the allowable lateral fracture cross section of a patient biasing moment M f, pr knowledge base with lateral bending load M e ratio is less than 120%, the pressure is maintained and lateral stress ⁇ b Pre-tighten the bending moment M f, pr and then proceed to step (6) in step 5; otherwise, proceed to step (5) in step 5;
  • the length of the extended branch chain can be stopped only within the range of 60% to 120%; if the ratio of the axial compressive stress ⁇ b to the allowable axial compressive stress ⁇ e of the fracture section is less than 60%, each time the first branched-chain length to shorter synchronization sixth branched 0.5mm, then repeating steps (1) in step 5, a compressive stress (3) axially ⁇ b is calculated, until the axial compressive stress fracture cross section of a patient with the allowable ⁇ b Only when the ratio of the axial compressive stress ⁇ e is in the range of 60% to 120% can the shortening of the branch chain length be stopped;
  • step (1) the lateral pre-tightening bending moment M f, pr until the lateral pre-tightening bending moment M f, pr of the fractured section of the patient and Knowledge allowable lateral bending load M e ratio is lower than 120% before stopping adjusting the length of the branched chain;
  • step (3) While repeating step (3) in step 5 daily to evaluate the mechanical status of the section, the computer system analyzes the changes in the mechanical status of the fracture section of the patient in the last 5 days, and provides the patient with suggestions for adjusting the amount of rehabilitation training exercise:
  • the daily axial compressive stress ⁇ b of the fracture section is continuously lower than the previous day and the cumulative reduction is greater than 15%. Then the patient is recommended to perform some standing and walking activities.
  • the patient is advised to appropriately reduce the activities of standing and walking; if the axial compressive stress ⁇ b of the fracture section does not exceed 15% within five days, the patient The amount of rehabilitation training is relatively reasonable, and maintaining this amount will promote the rehabilitation of fractures;
  • Step 6 When the patient's fracture rehabilitation is in the second stage, use the following steps to select the appropriate time to remove the six-axis parallel bone external fixation device to complete the fracture rehabilitation:
  • the six-axis parallel bone external fixation device is divided into a metal bone needle subsystem, a fixed ring subsystem and a branch chain subsystem, and the stiffness matrix of each subsystem is established separately ;
  • the computer system determines the spatial relative relationship of each of the subsystems based on the spatial position and attitude of the six-axis parallel bone external fixation device obtained in step 5, and then each of the subsystems is based on the virtual work principle and the deformation superposition principle
  • the stiffness matrices are linearly superimposed to establish the stiffness model of the six-axis parallel bone external fixation device described by the stiffness matrix K fx ;
  • F ve and ⁇ ve in formula (1-3) respectively represent the force spirals of the stent in the standing posture
  • the computer system decomposes the linear force component f ve of the force spiral of the standing posture support along the direction of the backbone axis to obtain the axial force F f, ve of the standing posture support; and then uses the formula (1- 4) Calculate the epiphyseal axial rehabilitation force F b, ve at the fracture site:
  • F st and ⁇ st in Eq. (1-5) respectively represent the force spirals of the stent in the forward-extended position
  • the computer system decomposes the force coupling component ⁇ st of the force spiral of the limb forward sitting posture bracket in a direction perpendicular to the backbone axis to obtain the bending moment M f, st of the limb sitting posture bracket; and then uses The following expression solves the limb bending moment M lb in the forward sitting posture:
  • G is the weight of the entire lower extremity of the patient's fracture site, which is obtained by the computer system querying the knowledge base based on the patient's physical factors.
  • F bd , d lb and d fr are the lateral bending force, total limb length and Fracture overhang distance; use formula (1-7) to calculate the lateral rehabilitation bending moment M b, st of the epiphysis :
  • K fx -1 represents the inverse matrix of the stiffness matrix K fx of the six-axis parallel bone external fixation device; the relative linear deformation ⁇ r, relative angular deformation ⁇ , and epiphyseal axial rehabilitation force F b, ve and The epiphyseal lateral rehabilitation bending moment M b, st uses the formula (1-9) to calculate the epiphyseal axial deformation energy E b, ve and the epiphyseal lateral deformation energy E b, st :
  • the ratio R ve of the axial deformation energy E b, ve of the epiphysis to work W t as the axial load performance index, and the ratio R of the lateral deformation energy E b, st of the epiphysis to work W t of the external load st is used as a lateral bearing performance index, and the axial bearing performance index R ve and the lateral bearing performance index R st are defined as quantitative evaluation indexes of fracture rehabilitation;
  • FIG. 1 is a schematic diagram of an original structure of a six-axis parallel bone external fixation device used in the evaluation method of the present invention
  • FIG. 2 is a schematic diagram of a method of installing the six-axis parallel bone external fixation device shown in FIG. 1;
  • FIG. 3 is a schematic structural diagram of a branch of a six-axis parallel bone external fixation device shown in FIG. 1;
  • FIG. 4A is a schematic diagram of a method for installing a cylindrical axial force sensor on a branch chain of the device shown in FIG. 1;
  • FIG. 4B is a schematic diagram of a method for installing an S-type axial force sensor in the device shown in FIG. 1;
  • FIG. 5 is an effect view of fixing a fracture site using an external fixing device equipped with a sensor
  • FIG. 6 is a schematic structural diagram of a connection between a force sensor and a sensing signal transmission device through a signal cable;
  • FIG. 7 is a schematic diagram of the effect of adding a marker to the proximal fixing ring and the distal fixing ring of the device shown in FIG. 1;
  • FIG. 8 is a schematic structural diagram of a marker
  • 9 is a three-dimensional image rendering of a fractured bone mass and a labeled sphere obtained by scanning and processing using a medical three-dimensional CT imaging device;
  • FIG. 10 is a flowchart of a rehabilitation method in the first period of fracture rehabilitation according to the present invention.
  • FIG. 11 is a schematic diagram of a method for detecting a pre-tightening load of an external fixation device by using a sitting posture without a load on a patient;
  • Figure 12 is a three-dimensional graphical software interface for calculating the bearing area of a fractured end
  • FIG. 13 is a flowchart of a rehabilitation method for the second period of fracture rehabilitation according to the present invention.
  • FIG. 14A is a schematic diagram of a method in which a patient adopts a standing posture to detect an axial load of a limb;
  • 14B is a schematic diagram of the geometric relationship between the external fixation bracket and the force of the fracture site when the patient takes a standing posture
  • 15 is a schematic diagram of a method for detecting a lateral load of a limb by a patient in a sitting posture with a fractured limb extended.
  • the method of the present invention can adopt the existing six-axis parallel bone external fixation device and modify it.
  • the six-axis parallel bone external fixation device generally consists of two fixing rings and six adjustable-length branch chains.
  • For the structure of the six-axis parallel bone external fixation device refer to CN202365897, US6030386, and WO2011163406.
  • the six-axis parallel bone external fixation device includes a proximal fixing ring 101, a distal fixing ring 102, a first branch 103, a second branch 104, a third branch 105, a fourth branch 106, and a fifth branch.
  • Chain 107 and sixth branch 108 (see Figure 1).
  • the proximal fixed ring 101 and the distal fixed ring 102 have the same ring structure, and six protruding parts are evenly spaced on the outer peripheral wall of the ring structure; on the ring structure
  • a plurality of inner ring connection holes with an axis in the vertical direction are evenly spaced throughout the circumference, and outer ring connection holes with the axis in the vertical direction are evenly spaced at the protruding portions.
  • the inner ring connection hole and the outer ring connection hole can be connected with a metal bone needle through a fixing nut / fixing post, and the fracture bone mass can be fixed by the metal bone needle (see FIG. 5).
  • branches with the same structure are arranged between the proximal fixing ring 101 and the distal fixing ring 102.
  • the arrangement of the branch chains is as follows. According to the method shown in FIG. 2, the outer rings on the two sides of the outer ring connection holes on the second, fourth and sixth protruding parts of the proximal fixing ring 101 are selected.
  • Connection holes (a total of 6 outer ring connection holes of the proximal fixing ring 101), which sequentially connect the hinges on the upper ends of the first branch 103 to the sixth branch 108; select the first on the distal fixing ring Of the outer ring connection holes of the third, third, and fifth protruding parts, the outer ring connection holes on both sides (a total of six outer ring connection holes of the distal fixing ring 102) are connected in sequence to the first branch chain 103 A hinge to the lower end of the sixth branch chain 108; forming a first branch chain 103 to a sixth branch chain 108 as a whole along the circumferential direction, and adjacent branch chains are arranged in a broken line to complete the connection of the branch chains.
  • the six branch chains are all composed of a first Hooker hinge 301 at the upper end of the branch chain, a drive screw 302 in the middle of the branch chain, and a second Hooker hinge 303 at the lower end of the branch chain.
  • the first Hooker hinge 301 has two degrees of rotation freedom R 1 and degree of rotation R 2 perpendicular to the axis A 1 and the axis A 2 perpendicular to each other around the cross shaft structure.
  • the connecting bolt 304 After the connecting bolt 304 is connected to the proximal fixing ring 101, the connecting bolt 304 has a rotational degree of freedom R 3 about the axis A 3 of the connection hole of the outer ring; the driving screw 302 can convert the operation 310 of the operator to rotate the driving nut into a screw along the screw.
  • Hook said second hinge 303 has a configuration of the cross shaft about its two axes perpendicular to each other a 5,
  • the rotational degrees of freedom R 5 and R 6 of A 6 are connected to the distal end fixing ring 102 through the distal connecting bolt 305 and have the rotational degrees of freedom R 7 around the axis A 7 of the outer ring connection hole.
  • the operator adjusts the driving screw 302 of the first branch chain 103 to the sixth branch chain 108 according to a certain rule; by changing the length of the branch chain, a six-degree-of-freedom relative movement between the proximal fixed ring 101 and the distal fixed ring 102 can be formed.
  • the relative movement drives the proximal bone mass and the distal bone mass of the fracture site to perform relative adjustment to achieve reduction of the fracture.
  • the fracture rehabilitation evaluation method based on the six-axis parallel bone external fixation device of the present invention includes the following steps:
  • Step 1 Modify the six-axis parallel bone external fixation device:
  • (1) Prepare the components of the existing six-axis parallel bone external fixation device, including a proximal fixation ring 101, a distal fixation ring 102, and a connection between the proximal fixation ring 101 and the distal fixation ring 102.
  • the first branch 103, the second branch 104, the third branch 105, the fourth branch 106, the fifth branch 107, and the sixth branch 108 of each of the branches A hinge 301, a driving screw 302 in the middle of the branch, and a second Hook hinge 303 at the lower end of the branch;
  • the six branch chains of the existing six-axis parallel bone external fixation device are equipped with tension pressure sensors by the following methods: first Hook hinges 301 of the first branch 103 to the sixth branch 108 and The driving screw 302 is disassembled, and an axial force sensor is coaxially fixed between the two; as shown in FIGS. 4A and 4B, the axial force sensor may be a commercially available cylindrical axial force sensor 401 or S.
  • a cylindrical axial force sensor (hereinafter referred to as a force sensor) 401 is added to the six branch chains.
  • the proximal fixation ring 101, the distal fixation ring 102, and the proximal bone block of the fracture site are connected by a metal bone needle and a bone needle connection part And distal bone pieces are fixedly connected.
  • FIG. 5 The effect of using the modified six-axis parallel bone external fixation device to fix a fracture site is shown in FIG. 5.
  • Step 2 Adjust the six-axis parallel bone external fixation device to reduce fracture deformity.
  • the steps are: according to the method proposed by CN202365897 or US5728095 and other patents, obtain the six-axis parallel bone external fixation device adjustment plan required to reduce fracture deformity, and follow the instructions.
  • the adjustment scheme adjusts the length of the six branches to reduce the fracture deformity; after the fracture reduction is completed, the length of the six branches is locked and the fracture site is fixed.
  • Step 3 Identify the spatial location of the marker and fracture bone:
  • the structure includes a marking sphere 801 and a connecting pin 802 (see FIG. 8); each of the markers is connected to the inner ring of the proximal fixing ring 101 or the distal fixing ring 102 through a shaft at the lower end of the connecting pin 802.
  • the holes form a fixed connection; the marking sphere 801 is made of metal material, and the marking pin 802 is processed by plastic material, so that the marking sphere 801 can be recognized by general medical CT imaging equipment, and the connecting pin 802 will not be recognized. .
  • Step 4 According to the fracture rehabilitation stage division method commonly used in the clinical field, the rehabilitation stage is divided into three stages: hematoma mechanization stage, primitive epiphyseal stage, and epiphyseal reconstruction stage based on bone tissue growth.
  • the hematoma mechanization period and the original callus period are referred to as a first period, and the callus reconstruction period is referred to as a second period.
  • Step 5 When the patient's fracture rehabilitation is in the first stage, follow the steps below to fine-tune the six-axis parallel bone external fixation device and guide the patient in rehabilitation training (see Figure 10):
  • the computer system uses a spherical fitting algorithm to automatically identify the six spherical center coordinates of the first three-dimensional sphere 903 to the sixth three-dimensional sphere 908; using a spatial geometric algorithm, respectively Use the center coordinates of the first three-dimensional sphere 903, the second three-dimensional sphere 904, and the third three-dimensional sphere 905 to identify a plane Puv that coincides with the upper surface of the proximal fixing ring 101, and use the geometric center point of the upper surface of the proximal fixing ring 101 as The origin P of the coordinate system, with the vector formed by the origin P to the projection point of the first three-dimensional sphere 903 on the plane Puv as the coordinate axis Take the vector passing through point P and parallel to the direction of the plane Puv normal vector as the coordinate axis According to the right-hand rule, a proximal coordinate system P-uvw fixedly connected to the proximal fixing ring 101 is established; similarly, the center
  • a far-end coordinate system O-xyz fixedly connected to the far-end fixation ring 102 (the established coordinate system near-end P-uvw and far-end coordinate system O-xyz and the actual near-end fixation ring 101 and the far end are established
  • the spatial correspondence of the fixed ring 102 is shown in Figure 7); the coordinate position P-uvw and the coordinate system O-xyz are used to determine the spatial position and attitude of the six-axis parallel bone external fixation device;
  • ⁇ pr represents the pretension force spiral Of the force couple component.
  • the linear force component f pr of the pre-stressed linear force spiral is decomposed along the direction of the backbone axis 910 specified in step 3 to obtain the axial axial pre-tension force F f, pr .
  • the pre-tension force couple ⁇ pr is perpendicular to the backbone axis 910.
  • the lateral pre-stressing bending moment M f, pr of the backbone is obtained; the axial pre-tensioning force F f, pr of the backbone and the lateral pre-tensioning moment M f, pr of the backbone indicate a six-axis parallel bone external fixation device
  • the combined force of the six branches provides a preload to the fracture backbone.
  • the computer system uses a graphical software interface to display the three-dimensional image stored in the computer system in step three (a feasible but not the only graphical software interface is shown in Figure 12), The operator specifies the backbone cross-section 1201 near the fracture cross-section in the graphical software interface.
  • the computer system uses a graphical intersection algorithm to automatically identify the annular graphic area 1202 corresponding to the cortical bone at the designated backbone cross-section 1201, and then calculates The bearing area S b of the fracture end corresponding to the annular pattern area 1202.
  • the computer system calculates the axial compressive stress ⁇ b of the fracture section and the lateral pre-stressing moment M f, pr of the fracture section;
  • the axial compressive stress ⁇ b and the lateral pre-stressed bending moment M f, pr of the backbone are compared with the allowable axial compressive stress ⁇ e and the allowable lateral bending load M e provided by the knowledge base , respectively.
  • the ratio of the axial compressive stress ⁇ b to the allowable axial compressive stress ⁇ e is in the range of 60% to 120%, and the lateral pre-stressing moment M f, pr of the fractured section of the patient and the permitted side of the knowledge base the ratio of the bending load M e is less than 120%, the compressive stress ⁇ b holds the preload and laterally bending moment M f, pr, and then proceeds to step (6) in step 5; otherwise, the step is step 5 ( 5).
  • the length of the first branch 103 to the sixth branch 108 is shortened by 0.5 mm to increase the axial direction of the fracture end.
  • Compressive stress ⁇ b then repeat steps (1) and (3) in step 5 to calculate the axial compressive stress ⁇ b until the ratio of the axial compressive stress ⁇ b to the allowable axial compressive stress ⁇ e of the fractured section of the patient is between Only within the range of 60% to 120% (such as: 60%, 80%, 120%, etc.) can the stop shortening the length of the branch chain.
  • step (1) each time the longitudinal direction of the inner moment branched chain elongation 0.5mm, while the moment direction Shorten the length of the lateral branch chain by 0.5mm to reduce the lateral pre-tightening bending moment M f, pr , and then repeat step (1) in step 5 to calculate the lateral pre-tightening bending moment M f, pr until the side of the fractured section of the patient Xu biasing the bending moment M f, pr and the knowledge base with a lateral bending load M e ratio is lower than 120% before adjusting the length of the stop branched.
  • step (3) While repeating step (3) in step 5 daily to evaluate the mechanical status of the section, the computer system analyzes the changes in the mechanical status of the fracture section of the patient in the last 5 days, and provides the patient with suggestions for adjusting the amount of rehabilitation training exercise:
  • the daily axial compressive stress ⁇ b of the fracture section is continuously reduced compared to the previous day and the cumulative decrease is greater than 15%. Then the patient is recommended to perform some standing and walking activities. If the daily axial compressive stress ⁇ of the fracture section is appropriate, b compared with the previous day, and the cumulative increase is greater than 15%, the patient is recommended to appropriately reduce the activities of standing and walking; if the axial compressive stress ⁇ b of the fracture section does not exceed 15% within five days, the patient The amount of rehabilitation training is relatively reasonable. Maintaining this amount of exercise promotes the rehabilitation of fractures.
  • Step 6 When the patient's fracture rehabilitation is in the second stage, use the following steps to select the appropriate time to remove the six-axis parallel bone external fixation device and complete the fracture rehabilitation (see Figure 13):
  • the six-axis parallel bone external fixation device is divided into a metal bone needle subsystem, a fixed ring subsystem and a branch chain subsystem, and the stiffness matrix of each subsystem is established separately ;
  • a preferred method for establishing the stiffness matrix is: for the metal bone needle subsystem, the cantilever beam element model and the elastic string model are used to characterize the threaded half needle and Kirschner wire respectively, and then the deformation coordination equation is used to calculate A fixed pin stiffness mapping matrix K pin is established based on its inherent bending stiffness (for a specific method, see Nikonovas A.
  • the method of establishing the stiffness matrix can also refer to the method of rod element modeling in the book “Materials Mechanics", or use
  • the method of computer finite element simulation is not limited to the above.
  • the computer system determines the spatial relative relationship of each of the subsystems according to the spatial position and attitude of the six-axis parallel bone external fixation device obtained in step 5. Based on the virtual work principle and the deformation superposition principle, The stiffness matrices of the subsystems are linearly superimposed to establish a six-axis parallel bone external fixation device stiffness model described by a stiffness matrix K fx .
  • F ve and ⁇ ve in formula (1-3) respectively represent the force spirals of the stent in the standing posture
  • the computer system decomposes the linear force component f ve of the stent force spiral in the standing posture in the direction of the backbone axis 910 to obtain the axial force F f, ve of the stent in the standing posture; and then uses the formula ( 1-4) Calculate the axial rehabilitation force F b, ve of the epiphyseal borne by the fracture site:
  • F st and ⁇ st in Eq. (1-5) respectively represent the force spirals of the stent in the forward-extended position
  • the computer system decomposes the force coupling component ⁇ st of the force spiral of the limb forward sitting posture bracket in a direction perpendicular to the backbone axis 910 to obtain the bending moment M f, st of the limb sitting posture bracket; then Use formula (1-6) to solve the limb bending moment M lb (see Figure 15):
  • G is the weight of the entire lower extremity of the patient's fracture site, which is obtained by the computer system querying the knowledge base based on the patient's physical factors.
  • F bd , d lb and d fr are the lateral bending force, total limb length and Fracture overhang.
  • K fx -1 represents the inverse matrix of the stiffness matrix K fx of the six-axis parallel bone external fixation device; the relative linear deformation ⁇ r, relative angular deformation ⁇ , and epiphyseal axial rehabilitation force F b, ve and The epiphyseal lateral rehabilitation bending moment M b, st uses the formula (1-9) to calculate the epiphyseal axial deformation energy E b, ve and the epiphyseal lateral deformation energy E b, st :
  • the ratio R ve of the axial deformation energy E b, ve of the epiphysis to work W t as the axial load performance index, and the ratio R of the lateral deformation energy E b, st of the epiphysis to work W t of the external load st is used as the lateral load bearing performance index, and the axial load bearing performance index R ve and the lateral load bearing performance index R st are defined as the fracture rehabilitation quantitative evaluation index.

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Description

基于六轴并联骨外固定装置的骨折康复评价方法 技术领域
本发明涉及骨科外固定技术领域，特别是涉及一种使用六轴并联骨外固定装置固定骨折并量化评价骨折康复状况的方法。
背景技术
骨科外固定技术是使用六轴并联骨外固定装置固定骨折断端，并为骨折愈合提供合适力学环境的骨外科治疗手段。专利US6030386、US8439914和专利WO2011163406提出了一类六轴并联骨外固定装置，这类装置由六条拓扑结构完全相同的支链和两个固定环组成。医生使用金属骨针将两个固定环分别与患者骨折两端的骨块固定连接；六条支链通过两端的铰链与两个固定环相连接。按规律调节六条支链的长度，可生成两个固定环的六自由度相对运动，精确地矫正骨折的空间畸形、实现骨折复位；骨折复位后，保持支链的长度，六轴并联骨外固定装置维持骨折断端的相对稳定。这类六轴并联骨外固定装置兼具复位和固定骨折断端的功能，具有广阔的应用前景。
骨折康复的过程中，患者携带六轴并联骨外固定装置进行康复训练活动，刺激骨折断面附近的骨痂愈伤组织生长、促进骨折愈合，并防止肢体关节的僵化。骨折完全康复后，需要及时地拆除六轴并联骨外固定装置，避免肢体功能受损、减少患者的身体和心理负担。如何有效评价骨折康复状况是确定六轴并联骨外固定装置合理拆除时机的关键。现有的骨折康复状况评价方法主要分为定性评判(例如，活动观察法、X射线影像观察法和超声波影像观察法等)和定量评价(例如，骨载荷测量法和骨痂刚度估算法)两类。定量评价方法具有更准确的判断效果，但往往需要骨外固定装置替换为专用设备。例如，专利US5873843和US5437668提出了一类使用骨骼承担的载荷评价康复状况的方法，主要包括：将原始固定骨折的外固定装置沿骨骼轴线方向的支柱拆除，替换为一根或多根柱状的力检测装置，形成与骨骼并联分担肢体轴向载荷的状态；测量患者肢体承担的总载荷，减去力传感装置反馈的器械承担载荷，计算骨骼承担的载荷；以骨骼承担载荷和肢体承担总载荷的比例为指标，反映骨骼的承载能力，评价康复效果。专利US5697165、EP1217960和US20130041288提出了一类基于骨痂刚度评价骨折康复状况的方法，主要包括：将原始固定骨折的外固定装置沿骨骼轴线方向的支柱拆除，在患肢贴近骨折部位的一侧，安装一根可检测平面/空间形变量的装置；向患肢施加一定量的载荷，测量骨折断端的相对形变量；借助载荷-形变关系计算骨痂组织的刚度，并以此为指标评价骨折康复的效果。这些骨折康复状况的定量评价方法主要存在如下问题：(1)需要拆除原有六轴并联骨外固定装置并安装专用检测设备，经济性和便捷性不高，且拆除支架时，可能会造成二次骨折；(2)基于骨载荷测量的评价方法采用较为粗糙的轴向加载模型和平均力计算方法，测量结果的精确性有待提高；(3)基于骨痂刚度估算的评价方法灵敏度不高，需要向骨折部位施加较大的载荷以检测出变形量进而估算骨痂刚度，而过大的载荷不利于骨折的康复，严重者会造成二次骨折。上述问题使骨折康复状况的定量评价方法难以应用于临床。
发明内容
本发明的目的在于克服已有技术的缺点，提供一种在不造成二次创伤的前提下，可长期准确地检测患者骨折康复状况的基于六轴并联骨外固定装置的骨折康复评价方法。
本发明的基于六轴并联骨外固定装置的骨折康复评价方法，包括以下步骤：
步骤一、改装六轴并联骨外固定装置：
(1)准备六轴并联骨外固定装置的组成部件，包括近端固定环、远端固定环以及待连接在所述的近端固定环和远端固定环之间的第一支链、第二支链、第三支链、第四支链、第五支链和第六支链，每条支链由支链上端的第一虎克铰链、支链中部的驱动丝杠和支链下端第二虎克铰链构成；
(2)将六轴并联骨外固定装置的六条支链加装拉压力传感器，方法为：将所述的第一支链至第六支链的第一虎克铰链和驱动丝杠拆分，在二者之间同轴固定一个轴向力传感器；
(3)将六个力传感器分别通过信号线缆与一个传感信号变送设备连接；
(4)通过金属骨针及骨针连接零件，将近端固定环、远端固定环与骨折部位的近端骨块和远端骨块分别固定连接；
(5)将加装力传感器后的第一支链至第六支链的两端分别与近端固定环和远端固定环连接；
步骤二、调节六轴并联骨外固定装置以复位骨折畸形，步骤为：获取复位骨折畸形所需的六轴并联骨外固定装置调节方案，并按照所述的调节方案调整六条支链的长度，复位骨折畸形；完成骨折复位后，锁定六条支链的长度、固定骨折部位；
步骤三、识别标记物及骨折骨块的空间位置：
(1)在所述的近端固定环的内圈连接孔上沿圆周方向均匀间隔安装第一标记物、第二标记物和第三标记物，在远端固定环的内圈连接孔上沿圆周方向均匀间隔安装第四标记物、第五标记物以及第六标记物；所述的第一标记物至第六标记物具有相同的结构，分别包括一个标记球体和连接销轴；每一个所述标记物通过连接销轴下端的轴体插入近端固定环或远端固定环的内圈连接孔形成固定连接；所述的标记球体使用金属材料，所述标记物销轴使用塑料材料加工；
(2)使用医学CT影像设备对患者骨折部位及六轴并联骨外固定装置进行扫描，并经过三维重建和处理后得到包括骨折近端三维实体、骨折远端三维实体、第一三维球体、第二三维球体、第三三维球体、第四三维球体、第五三维球体和第六三维球体的三维图像，并存储于所述的计算机系统中；
(3)操作者观察计算机系统中的三维图像，并在计算机系统的软件界面中手工指定骨干的轴线，然后将标记物拆除；
步骤四、依照临床领域常用的骨折康复阶段划分方法，基于骨组织生长情况将康复阶段划分为血肿机化期、原始骨痂期和骨痂改建期三个阶段。将所述的血肿机化期和原始骨痂期称为第一时期，将所述的骨痂改建期称为第二时期；
步骤五、患者的骨折康复处于第一时期时，按照以下步骤对六轴并联骨外固定装置进行微调，并指导患者进行康复训练：
(1)计算六轴并联骨外固定装置的预紧载荷，步骤为：
(a)患者采取无负重坐姿，通过六个所述的力传感器分别检测第一支链至第六支链各自承担的支链 预紧力f pr,i,(i＝1～6)，然后，六个力传感器将各个支链预紧力信号通过传感信号变送器无线传输至所述的计算机系统；
(b)所述的计算机系统针对步骤三获得的三维图像，采用球面拟合算法自动识别所述的第一三维球体至第六三维球体的六个球心坐标；采用空间几何算法，分别使用第一三维球体、第二三维球体和第三三维球体的球心坐标，识别与近端固定环上表面重合的平面Puv，以近端固定环上表面的几何中心点为坐标系原点P，以原点至第一三维球体球心在平面Puv的投影点构成的矢量为坐标轴
Figure PCTCN2018102721-appb-000001
以过点P且平行于平面Puv法向量方向的矢量为坐标轴
Figure PCTCN2018102721-appb-000002
按照右手定则建立与近端固定环固定相连的近端坐标系P-uvw；分别使用第四三维球体、第五三维球体和第六三维球体的球心坐标识别与远端固定环上表面重合的平面Oxy，以远端固定环上表面的几何中心点为坐标系原点O，以原点至第四三维球体球心在平面Oxy的投影点构成的矢量为坐标轴
Figure PCTCN2018102721-appb-000003
以过点O且平行于平面Oxy法向量方向的矢量为坐标轴
Figure PCTCN2018102721-appb-000004
按照右手定则建立与远端固定环固定相连的远端坐标系O-xyz；使用坐标系P-uvw和坐标系O-xyz确定六轴并联骨外固定装置的空间位置与姿态；
(c)所述的计算机系统借助并联机构运动学算法，由六轴并联骨外固定装置的空间位置与姿态计算第一支链至第六支链各自的空间轴线单位矢量n i,(i＝1～6)，然后计算轴线单位矢量n i,(i＝1～6)相对于近端坐标系P-uvw原点的单位预紧力螺旋
Figure PCTCN2018102721-appb-000005
然后通过公式(1-1)计算得到六轴并联骨外固定装置六条支链的合力提供给所述的骨折部位近端骨块和远端骨块之间的预紧力螺旋：
Figure PCTCN2018102721-appb-000006
式中，f pr表示预紧力螺旋
Figure PCTCN2018102721-appb-000007
的线性力分量，τ pr表示预紧力螺旋
Figure PCTCN2018102721-appb-000008
的力偶分量。将预紧线性力螺旋的线性力分量f pr沿步骤三指定的骨干轴线方向分解，得到骨干轴向预紧力F f,pr，将所述的预紧力偶τ pr沿垂直于骨干轴线的方向分解，得到骨干侧向预紧弯矩M f,pr；
(2)计算骨折断端承载面积：所述的计算机系统采用图形化软件界面显示步骤三中存储于计算机系统的三维图像，操作者在所述的图形化软件界面中指定骨折断面附近的骨干横截面，计算机系统采用图形学求交算法，自动识别指定骨干横截面处皮质骨对应的环状图形区域，进而计算环状图形区域对应的骨折断端承载面积S b；
(3)计算骨折断面应力：操作者统计患者的年龄、性别、身高和体重等体格因素并输入至所述的计算机系统中，通过查询相关的骨折康复知识库信息，得到该体格因素下，有助于患者骨折愈合的许用轴向压应力σ e和许用侧向弯曲载荷M e。所述的计算机系统使用骨干轴向预紧力F f,pr和骨折断端承载截面积S b、采用公式(1-2)计算骨折断面的轴向压应力σ b：
Figure PCTCN2018102721-appb-000009
(4)分析骨折部位力学状况：在整个骨折康复第一时期中，计算机系统每日计算所述的骨折断面轴向压应力σ b和骨干侧向预紧弯矩M f,pr，分别与所述的知识库提供的许用轴向压应力σ e和许用侧向弯曲载荷M e比较，若患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内，并且患者的骨折断面的侧向预紧弯矩M f,pr与知识库的许用侧向弯曲载荷M e的比值小于120％，则保持该压应力σ b和侧向预紧弯矩M f,pr，然后进行步骤五中的步骤(6)；否则，进行步骤五中的步骤(5)；
(5)优化患者的康复策略：若所述的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值大于120％，每次将第一支链至第六支链的长度同步伸长0.5mm，然后重复步骤五中的步骤(1)、(3)计算轴向压应力σ b，直至患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内方可停止伸长支链的长度；若所述的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值小于60％，每次将第一支链至第六支链的长度同步缩短0.5mm，然后重复步骤五中的步骤(1)、(3)计算轴向压应力σ b，直至患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内方可停止缩短支链的长度；
若所述侧向预紧弯矩M f,pr与许用侧向弯曲载荷M e的比值大于120％，则每次将伸长弯矩方向内侧支链的长度伸长0.5mm、同时将弯矩方向外侧支链的长度缩短0.5mm，然后重复步骤五中的步骤(1)计算侧向预紧弯矩M f,pr，直至患者的骨折断面的侧向预紧弯矩M f,pr与知识库的许用侧向弯曲载荷M e的比值小于120％方可停止调节支链的长度；
(6)在每日重复步骤五中的步骤(3)评价断面力学状况的同时，计算机系统分析患者最近5日的骨折断面力学状况的变化情况，并向患者提供康复训练运动量的调整建议：若骨折断面的每日轴向压应力σ b相较前一日不断降低且累计降低幅度大于15％，则向患者建议适当进行一些站立及行走的活动；若骨折断面的轴向压应力σ b每日相较前一日不断增加且累计增加幅度超出15％，则向患者建议适当减少站立及行走的活动；若骨折断面的轴向压应力σ b在五日内变化幅度不超过15％，则患者的康复训练运动量较为合理，保持该运动量促进骨折的康复；
(7)根据临床的经验，当患者骨折断端的骨痂生长充分后，拍摄骨痂的X射线影像并加以分析，患者是否完成骨折康复第一时期的愈合；
步骤六、患者骨折康复处于第二时期时，采用如下步骤选择合适的时机拆除六轴并联骨外固定装置、完成骨折康复：
(1)建立六轴并联骨外固定装置刚度模型：将所述的六轴并联骨外固定装置划分为金属骨针子系统、固定环子系统和支链子系统，分别建立各个子系统的刚度矩阵；所述的计算机系统依据步骤五获得的六 轴并联骨外固定装置的空间位置与姿态，确定各所述子系统的空间相对关系，然后基于虚功原理和变形叠加原理将各所述子系统的刚度矩阵线性叠加，建立以刚度矩阵K fx描述的六轴并联骨外固定装置刚度模型；
(2)计算骨折康复二期载荷，步骤为：
(a)检测肢体轴向载荷，患者采取站立姿势，使用患肢底部布置的电子称量设备检测肢体轴向压力F lb，操作者将所述的轴向压力F lb输入计算机系统；通过六个力传感器分别检测站立姿势六轴并联骨外固定装置各支链的轴向力f ve,i,(i＝1～6)，六个力传感器然后将站立姿势下各个支链的轴向力信号通过传感信号变送器传输至计算机系统，根据公式(1-3)计算六轴并联骨外固定装置承担的站立姿势支架力螺旋：
Figure PCTCN2018102721-appb-000010
式(1-3)中f ve和τ ve分别表示站立姿势支架力螺旋
Figure PCTCN2018102721-appb-000011
的线性力分量和力偶分量；计算机系统将所述的站立姿势支架力螺旋的线性力分量f ve沿骨干轴线的方向分解，得到站立姿势支架轴向力F f,ve；然后采用公式(1-4)计算得到骨折部位承担的骨痂轴向康复力F b,ve：
F b,ve＝F lb-F f,ve           (1-4)
(b)检测肢体侧向载荷，步骤为：患者采取骨折肢体前伸的坐姿，使用布置在骨折肢体足底的电子称量设备检测肢体侧向弯曲力F bd，同时使用尺测量肢体从臀部与座椅支撑点至足底与电子称量设备支撑点之间的总长度d lb、以及从骨折断端至足底与电子称量设备支撑点之间的骨折断端悬距d fr，操作者将上述数据输入至计算机系统；通过六个力传感器分别检测六轴并联骨外固定装置各支链的轴向力f st,i,(i＝1～6)，六个力传感器然后将肢体前伸坐姿下各个支链的轴向力信号通过传感信号变送器传输至计算机系统，根据公式(1-5)计算六轴并联骨外固定装置承担的肢体前伸坐姿支架力螺旋：
Figure PCTCN2018102721-appb-000012
式(1-5)中f st和τ st分别表示肢体前伸坐姿支架力螺旋
Figure PCTCN2018102721-appb-000013
的线性力分量和力偶分量；计算机系统将所述的肢体前伸坐姿支架力螺旋的力偶分量τ st沿垂直于骨干轴线的方向分解，得到肢体前伸坐姿支架弯矩M f,st；然后使用以下表达式求解肢体前伸坐姿肢体弯矩M lb：
M lb＝(G-F bd)(d lb-d fr)               (1-6)
其中，G为患者骨折部位全下肢的重量，由计算机系统依据患者的体格因素查询知识库得到，F bd、d lb和d fr分别为本步骤测量得到的肢体侧向弯曲力、肢体总长度和骨折断端悬距；使用公式(1-7)计算得到骨痂侧向康复弯矩M b,st：
M b,st＝M lb-M f,st              (1-7)
(c)定义骨折康复量化指标：计算机系统基于步骤六的步骤(1)建立的六轴并联骨外固定装置刚度矩阵K fx，由所述站立姿势支架力螺旋
Figure PCTCN2018102721-appb-000014
和肢体前伸坐姿支架力螺旋
Figure PCTCN2018102721-appb-000015
使用公式(1-8)分别求解六轴并联骨外固定装置两端发生的相对线变形δr和相对角变形δθ，所述的相对线变形δr和相对角变形δθ等效于骨折部位的骨痂变形量：
Figure PCTCN2018102721-appb-000016
式中K fx -1表示所述的六轴并联骨外固定装置刚度矩阵K fx的逆矩阵；由所述的相对线变形δr、相对角变形δθ、骨痂轴向康复力F b,ve和骨痂侧向康复弯矩M b,st，使用公式(1-9)计算骨痂轴向变形能E b,ve和骨痂侧向变形能E b,st：
Figure PCTCN2018102721-appb-000017
由所述的相对线变形δr、相对角变形δθ、站立姿势支架轴向力F f,ve和前伸姿势支架弯矩M f,st，使用公式(1-10)计算外界载荷做功W t：
Figure PCTCN2018102721-appb-000018
将所述骨痂轴向变形能E b,ve与外界载荷做功W t的比值R ve作为轴向承载性能指标，将骨痂侧向变形能E b,st与外界载荷做功W t的比值R st作为侧向承载性能指标，将所述的轴向承载性能指标R ve和侧向承载性能指标R st定义为骨折康复量化评价指标；
(d)综合量化评价骨折的愈合效果：患者每日分早、中、晚三次采取步骤(a)至步骤(c)的方法，测算轴向承载性能指标R ve和侧向承载性能指标R st的数值；通过查询所述的骨折康复知识库信息，获得包括轴向承载性能阈值R ve,b和侧向承载性能阈值R st,b的患者骨折康复量化指标阈值。分别计算轴向承载性能指标R ve与轴向承载性能阈值R ve,b的比值λ ve、侧向承载性能指标R st与侧向承载性能阈值R st,b的比值λ st，若每日三次测得的所述比值λ ve≥85％且λ st≥85％，表示患者的骨折康复效果良好，可安全拆除六轴并联骨外固定装置；否则，需要继续携带支架进行骨折的康复，直至所测得康复量化指标符合要求。
本发明的有益效果是：
(1)在市售的各类六轴并联骨外固定装置的基础上，经简单改装即可实现骨折康复状况的实时在线评价，适用范围广、经济性好；
(2)评价骨折康复的过程不需要拆除原有的外固定装置，可有效避免二次创伤或再骨折的发生；
(3)使用基于能量分析的量化指标评价骨折区域的承载性能，精确可靠地反映骨折康复的状况、及时合理地指导六轴并联骨外固定装置的拆除；
(4)量化指标的测量和计算不需要采取施加指定载荷或检测微小变形量，操作方便快捷且误差小。
附图说明
图1是本发明的评价方法所采用的一种六轴并联骨外固定装置的原始结构示意图；
图2是图1所示六轴并联骨外固定装置的安装方法示意图；
图3是图1所示六轴并联骨外固定装置的支链的结构示意图；
图4A是在图1所示装置的支链加装圆柱型轴向力传感器的方法示意图；
图4B是在图1所示的装置加装S型轴向力力传感器的方法示意图；
图5是使用经加装传感器的外固定装置固定骨折部位的效果图；
图6是力传感器与传感信号变送设备通过信号线缆连接的结构示意图；
图7是在图1所示装置的近端固定环和远端固定环加装标记物的效果示意图；
图8是标记物的结构示意图；
图9是使用医学三维CT影像设备扫描与处理得到的一种包含骨折骨块与标记球体的三维图像效果图；
图10是本发明的骨折康复第一时期的康复方法流程框图；
图11是患者采取无负重坐姿检测外固定装置预紧载荷的方法示意图；
图12是一种计算骨折断端承载面积的三维图形化软件界面；
图13是本发明的骨折康复第二时期的康复方法流程框图；
图14A是患者采取站立姿势检测肢体轴向载荷的方法示意图；
图14B是患者采取站立姿势下外固定支架和骨折部位受力的几何关系示意图；
图15是患者采取骨折肢体前伸的坐姿检测肢体侧向载荷的方法示意图。
具体实施方式
下面结合附图，对本发明的具体实施方式进行详细说明。
本发明方法可以采用现有的六轴并联骨外固定装置并加以改装应用即可，所述的六轴并联骨外固定装置一般由两个固定环和六根长度可调节的支链构成。所述的六轴并联骨外固定装置的结构可以参考CN202365897、US6030386和WO2011163406等专利。
下面结合附图简要说明CN202365897中公开的六轴并联骨外固定装置的结构：
所述的六轴并联骨外固定装置包括近端固定环101、远端固定环102、第一支链103、第二支链104、第三支链105、第四支链106、第五支链107和第六支链108(见图1)。所述的近端固定环101和远端固定环102具有相同的环状结构，在所述的环状结构的外周壁上均匀间隔的设置有6个突出部位；在所述的环状结构上整周均匀间隔的开有轴线沿竖直方向的多个内圈连接孔，在所述的突出部位上均匀间隔 的开有轴线沿竖直方向的外圈连接孔。所述的内圈连接孔和外圈连接孔可以通过固定螺母/固定立柱与金属骨针连接，并通过金属骨针固定骨折骨块(见图5)。
在所述的近端固定环101和远端固定环102之间设置有结构相同的六条支链。支链的布置方式为，按照图2所示的方法，选择所述的近端固定环101上第二、第四和第六个突出部位上的外圈连接孔中分别位于两侧的外圈连接孔(共6个近端固定环101的外圈连接孔)，按顺序连接所述的第一支链103至第六支链108上端的铰链；选择所述的远端固定环上第一、第三和第五个突出部位的外圈连接孔中位于两侧的外圈连接孔(共6个远端固定环102的外圈连接孔)，按顺序连接所述的第一支链103至第六支链108下端的铰链；形成第一支链103至第六支链108整体沿圆周方向、相邻的支链呈折线状的布局，完成支链的连接。
所述的六条支链均由支链上端的第一虎克铰链301、支链中部的驱动丝杠302和支链下端第二虎克铰链303构成。如图3所示，所述的第一虎克铰链301具有绕自身十字轴结构的两个彼此垂直的轴线A 1和轴线A 2的转动自由度R 1和转动自由度R 2，通过近端连接螺栓304与近端固定环101连接后具有绕外圈连接孔的轴线A 3的转动自由度R 3；所述的驱动丝杠302可以将操作者旋转驱动螺母的操作310转换为沿丝杠轴线A 4方向的直线伸缩运动，具有沿丝杠轴线A 4方向的平动自由度P 1；所述的第二虎克铰链303具有绕自身十字轴结构的两个彼此垂直的轴线A 5、A 6的转动自由度R 5和转动自由度R 6，通过远端连接螺栓305与远端固定环102连接后具有绕外圈连接孔的轴线A 7的转动自由度R 7。操作者按照一定规律调节第一支链103至第六支链108的驱动丝杠302；改变支链的长度，可以形成近端固定环101与远端固定环102之间的六自由度相对运动，所述的相对运动带动骨折部位的近端骨块和远端骨块进行相对调节，实现骨折的复位。
本发明的基于六轴并联骨外固定装置的骨折康复评价方法，包括以下步骤：
步骤一、改装六轴并联骨外固定装置：
(1)准备现有的六轴并联骨外固定装置的组成部件，包括近端固定环101、远端固定环102以及待连接在所述的近端固定环101和远端固定环102之间的第一支链103、第二支链104、第三支链105、第四支链106、第五支链107和第六支链108，每条支链由支链上端的第一虎克铰链301、支链中部的驱动丝杠302和支链下端第二虎克铰链303构成；
(2)将现有的六轴并联骨外固定装置的六条支链加装拉压力传感器，方法为：将所述的第一支链103至第六支链108的第一虎克铰链301和驱动丝杠302拆分，在二者之间同轴固定一个轴向力传感器；如图4A、4B所示，所述的轴向力传感器可以采用市售的圆柱型轴向力传感器401或S型轴向力传感器402等形式，并借助内螺纹杆件410或外螺纹杆件411，分别与第一虎克铰链301下端的内螺纹和驱动丝杠302上端的外螺纹形成紧固连接。优选地，采用圆柱型轴向力传感器(以下简称力传感器)401加装于所述的六条支链中。
(3)将六个力传感器401a、401b、401c、401d、401e、401f分别通过信号线缆与一个传感信号变送设备601连接(见图6)。
(4)采用与原始六轴并联骨外固定装置相同的固定环安装方法，通过金属骨针及骨针连接零件，将近端固定环101、远端固定环102与骨折部位的近端骨块和远端骨块分别固定连接。
(5)采用与原始六轴并联骨外固定装置相同的支链连接方法，将加装力传感器401后的第一支链103至第六支链108的两端分别与近端固定环101和远端固定环102连接。
使用经过上述改装的六轴并联骨外固定装置固定骨折部位的效果如图5所示。
步骤二、调节六轴并联骨外固定装置以复位骨折畸形，步骤为：按照CN202365897或US5728095等专利提出的方法，获取复位骨折畸形所需的六轴并联骨外固定装置调节方案，并按照所述的调节方案调整六条支链的长度，复位骨折畸形；完成骨折复位后，锁定六条支链的长度、固定骨折部位。
步骤三、识别标记物及骨折骨块的空间位置：
(1)在所述的近端固定环101的内圈连接孔上沿圆周方向均匀间隔安装第一标记物701、第二标记物702和第三标记物703，在远端固定环102的内圈连接孔上沿圆周方向均匀间隔安装第四标记物704、第五标记物705以及第六标记物706(见图7)；所述的第一标记物701至第六标记物706具有相同的结构，分别包括一个标记球体801和连接销轴802(见图8)；每一个所述标记物通过连接销轴802下端的轴体插入近端固定环101或远端固定环102的内圈连接孔形成固定连接；所述的标记球体801使用金属材料，所述标记物销轴802使用塑料材料加工，使得标记球体801可以被一般的医学CT影像设备识别，而连接销轴802不会被识别。
(2)使用医学CT影像设备对患者骨折部位及六轴并联骨外固定装置进行扫描，并经过三维重建和处理后得到包括骨折近端三维实体901、骨折远端三维实体902、第一三维球体903、第二三维球体904、第三三维球体905、第四三维球体906、第五三维球体907和第六三维球体908的三维图像(见图9)，并存储于所述的计算机系统中。
(3)操作者观察计算机系统中的三维图像，并在计算机系统的软件界面中手工指定骨干的轴线910(见图9)。完成本步骤后将标记物拆除。
步骤四、依照临床领域常用的骨折康复阶段划分方法，基于骨组织生长情况将康复阶段划分为血肿机化期、原始骨痂期和骨痂改建期三个阶段。将所述的血肿机化期和原始骨痂期称为第一时期，将所述的骨痂改建期称为第二时期。
步骤五、患者的骨折康复处于第一时期时，按照以下步骤对六轴并联骨外固定装置进行微调，并指导患者进行康复训练(见图10)：
(1)计算六轴并联骨外固定装置的预紧载荷，步骤为：
(a)患者采取无负重坐姿(见图11)，通过六个所述的力传感器401a、401b、401c、401d、401e、401f分别检测第一支链103至第六支链108各自承担的支链预紧力f pr,i,(i＝1～6)，然后，六个力传感器401a～401f将各个支链预紧力信号通过传感信号变送器601无线传输至所述的计算机系统；优选的，传感信号变送器601传输至所述的计算机系统中的信号可以通过蓝牙协议无线传输。
(b)所述的计算机系统针对步骤三获得的三维图像，采用球面拟合算法自动识别所述的第一三维球体903至第六三维球体908的六个球心坐标；采用空间几何算法，分别使用第一三维球体903、第二三维球体904和第三三维球体905的球心坐标，识别与近端固定环101上表面重合的平面Puv，以近端固定环101上表面的几何中心点为坐标系原点P，以原点P至第一三维球体903球心在平面Puv的投影点构 成的矢量为坐标轴
Figure PCTCN2018102721-appb-000019
以过点P且平行于平面Puv法向量方向的矢量为坐标轴
Figure PCTCN2018102721-appb-000020
按照右手定则建立与近端固定环101固定相连的近端坐标系P-uvw；类似地，分别使用第四三维球体906、第五三维球体907和第六三维球体908的球心坐标识别与远端固定环102上表面重合的平面Oxy，以远端固定环102上表面的几何中心点为坐标系原点O，以原点O至第四三维球体906球心在平面Oxy的投影点构成的矢量为坐标轴
Figure PCTCN2018102721-appb-000021
以过点O且平行于平面Oxy法向量方向的矢量为坐标轴
Figure PCTCN2018102721-appb-000022
按照右手定则建立与远端固定环102固定相连的远端坐标系O-xyz(所建立的坐标系近端P-uvw和远端坐标系O-xyz与实际近端固定环101和远端固定环102的空间对应关系如图7所示)；使用坐标系P-uvw和坐标系O-xyz确定六轴并联骨外固定装置的空间位置与姿态；
(c)所述的计算机系统借助并联机构运动学算法，由六轴并联骨外固定装置的空间位置与姿态计算第一支链103至第六支链108各自的空间轴线单位矢量n i,(i＝1～6)，然后计算轴线单位矢量n i,(i＝1～6)相对于近端坐标系P-uvw原点的单位预紧力螺旋
Figure PCTCN2018102721-appb-000023
(具体计算方法可以参见《高等空间机构学》一书的“螺旋理论基础”章节)；然后通过公式(1-1)计算得到六轴并联骨外固定装置六条支链的合力提供给所述的骨折部位近端骨块和远端骨块之间的预紧力螺旋：
Figure PCTCN2018102721-appb-000024
式中，f pr表示预紧力螺旋
Figure PCTCN2018102721-appb-000025
的线性力分量，τ pr表示预紧力螺旋
Figure PCTCN2018102721-appb-000026
的力偶分量。将预紧线性力螺旋的线性力分量f pr沿步骤三指定的骨干轴线910方向分解，得到骨干轴向预紧力F f,pr，将所述的预紧力偶τ pr沿垂直于骨干轴线910的方向分解，得到骨干侧向预紧弯矩M f,pr；所述的骨干轴向预紧力F f,pr和骨干侧向预紧弯矩M f,pr表示六轴并联骨外固定装置六条支链的合力向骨折骨干提供的预紧载荷。
(2)计算骨折断端承载面积：所述的计算机系统采用图形化软件界面显示步骤三中存储于计算机系统的三维图像(一种可行但不唯一的图形化软件界面如图12所示)，操作者在所述的图形化软件界面中指定骨折断面附近的骨干横截面1201，计算机系统采用图形学求交算法，自动识别指定骨干横截面1201处皮质骨对应的环状图形区域1202，进而计算环状图形区域1202对应的骨折断端承载面积S b。
(3)计算骨折断面应力：操作者统计患者的年龄、性别、身高和体重等体格因素并输入至所述的计算机系统中，通过查询相关的骨折康复知识库信息，得到该体格因素下，有助于患者骨折愈合的许用轴向压应力σ e和许用侧向弯曲载荷M e。所述的计算机系统使用骨干轴向预紧力F f,pr和骨折断端承载截面积S b、采用公式(1-2)计算骨折断面的轴向压应力σ b：
Figure PCTCN2018102721-appb-000027
(4)分析骨折部位力学状况：在整个骨折康复第一时期中，计算机系统每日计算所述的骨折断面 轴向压应力σ b和骨干侧向预紧弯矩M f,pr；将骨折断面轴向压应力σ b和骨干侧向预紧弯矩M f,pr分别与所述的知识库提供的许用轴向压应力σ e和许用侧向弯曲载荷M e比较，若患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内，并且患者的骨折断面的侧向预紧弯矩M f,pr与知识库的许用侧向弯曲载荷M e的比值小于120％，则保持该压应力σ b和侧向预紧弯矩M f,pr，然后进行步骤五中的步骤(6)；否则，进行步骤五中的步骤(5)。
(5)优化患者的康复策略：若所述的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值大于120％，每次将第一支链103至第六支链108的长度同步伸长0.5mm以减少骨折断端的轴向压应力σ b，然后重复步骤五中的步骤(1)、(3)计算轴向压应力σ b，直至患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％(如：60％、100％、120％等)范围内方可停止伸长支链的长度；若所述的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值小于60％，每次将第一支链103至第六支链108的长度同步缩短0.5mm以增加骨折断端的轴向压应力σ b，然后重复步骤五中的步骤(1)、(3)计算轴向压应力σ b，直至患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％(如：60％、80％、120％等)范围内方可停止缩短支链的长度。
若所述侧向预紧弯矩M f,pr与许用侧向弯曲载荷M e的比值大于120％，则每次将弯矩方向内侧支链的长度伸长0.5mm、同时将弯矩方向外侧支链的长度缩短0.5mm以减少侧向预紧弯矩M f,pr，然后重复步骤五中的步骤(1)计算侧向预紧弯矩M f,pr，直至患者的骨折断面的侧向预紧弯矩M f,pr与知识库的许用侧向弯曲载荷M e的比值小于120％方可停止调节支链的长度。
(6)在每日重复步骤五中的步骤(3)评价断面力学状况的同时，计算机系统分析患者最近5日的骨折断面力学状况的变化情况，并向患者提供康复训练运动量的调整建议：若骨折断面的每日轴向压应力σ b相较前一日不断降低且累计降低幅度大于15％，则向患者建议适当进行一些站立及行走的活动；若骨折断面的每日轴向压应力σ b相较前一日不断增加且累计增加幅度大于15％，则向患者建议适当减少站立及行走的活动；若骨折断面的轴向压应力σ b在五日内变化幅度不超过15％，则患者的康复训练运动量较为合理，保持该运动量促进骨折的康复。
(7)根据临床的经验，当患者骨折断端的骨痂生长充分后，拍摄骨痂的X射线影像并加以分析，患者是否完成骨折康复第一时期的愈合。
步骤六、患者骨折康复处于第二时期时，采用如下步骤选择合适的时机拆除六轴并联骨外固定装置、完成骨折康复(见图13)：
(1)建立六轴并联骨外固定装置刚度模型：将所述的六轴并联骨外固定装置划分为金属骨针子系统、固定环子系统和支链子系统，分别建立各个子系统的刚度矩阵；一种优选的刚度矩阵的建立方法为：针对所述的金属骨针子系统，分别采用悬臂梁单元模型和弹性弦丝模型表征螺纹半针和克氏针，进而借助 变形协调方程并计入其固有弯曲刚度建立固定针刚度映射矩阵K pin(具体方法可以参见NikonovasA.等2005年发表于Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine机械工程协会医学工程杂志的文献——A simple way to model wires used in ring fixators:analysis of the wire stiffness effect on overall fixator stiffness一种简单环形外固定器钢丝针的建模方法：分析钢丝针刚度对固定器全局刚度的影响)；针对所述的固定环子系统，采用常曲率曲梁的单元刚度矩阵(具体方法可以参见刘铁林等2013年发表于沈阳建筑大学学报(自然科学版)的文献——面内变形曲梁的显式单元刚度矩阵)建立固定环刚度映射矩阵K rng；针对所述的支链子系统，借助虚功原理求解各部件的刚度映射模型(具体方法可以参见El-Khasawneh B S等1999年发表于International Journal of Machine Tools and Manufacture(国际机床与制造杂志)的文献Computation of stiffness and stiffness bounds for parallel link manipulators(并联机构支链刚度与界面刚度的计算)，进而建立各个支链刚度映射矩阵K str。当然刚度矩阵的建立方法也可以参考《材料力学》书籍的杆单元建模方法、或者使用计算机有限元仿真的方法建立，并不局限于以上形式。所述的计算机系统依据步骤五获得的六轴并联骨外固定装置的空间位置与姿态，确定各所述子系统的空间相对关系，然后基于虚功原理和变形叠加原理将各所述子系统的刚度矩阵线性叠加，建立以刚度矩阵K fx描述的六轴并联骨外固定装置刚度模型。
(2)计算骨折康复二期载荷，步骤为：
(a)检测肢体轴向载荷，患者采取站立姿势，使用设置在骨折肢体足底的电子称量设备1401检测肢体轴向压力F lb(见图14A)，操作者将所述的轴向压力F lb输入计算机系统；通过六个力传感器402a、402b、402c、402d、402e、402f分别检测站立姿势下六轴并联骨外固定装置各支链的轴向力f ve,i,(i＝1～6)，六个力传感器然后将站立姿势下各个支链的轴向力信号通过传感信号变送器601传输至计算机系统，根据公式(1-3)计算六轴并联骨外固定装置承担的站立姿势支架力螺旋：
Figure PCTCN2018102721-appb-000028
式(1-3)中f ve和τ ve分别表示站立姿势支架力螺旋
Figure PCTCN2018102721-appb-000029
的线性力分量和力偶分量；计算机系统将所述的站立姿势下支架力螺旋的线性力分量f ve沿骨干轴线910的方向分解，得到站立姿势支架轴向力F f,ve；然后采用公式(1-4)计算得到骨折部位承担的骨痂轴向康复力F b,ve：
F b,ve＝F lb-F f,ve              (1-4)
上述的支链轴向力f ve,i,(i＝1～6)、肢体轴向压力F lb和骨痂轴向康复力F b,ve的空间几何关系如图14B所示。
(b)检测肢体侧向载荷，步骤为：患者采取骨折肢体前伸的坐姿，使用布置在骨折肢体足底的电子称量设备1401检测肢体侧向弯曲力F bd，同时使用尺测量肢体从臀部与座椅支撑点至足底与电子称量设备1401支撑点之间的总长度d lb、以及从骨折断端至足底与电子称量设备1401支撑点之间的骨折断 端悬距d fr(见图15)，操作者将上述数据输入至计算机系统；通过六个力传感器402a、402b、402c、402d、402e、402f分别检测六轴并联骨外固定装置各支链的轴向力f st,i,(i＝1～6)，六个力传感器然后将肢体前伸坐姿下各个支链的轴向力信号通过传感信号变送器601传输至计算机系统，根据公式(1-5)计算六轴并联骨外固定装置承担的肢体前伸坐姿支架力螺旋：
Figure PCTCN2018102721-appb-000030
式(1-5)中f st和τ st分别表示肢体前伸坐姿支架力螺旋
Figure PCTCN2018102721-appb-000031
的线性力分量和力偶分量；计算机系统将所述的肢体前伸坐姿支架力螺旋的力偶分量τ st沿垂直于骨干轴线910的方向分解，得到肢体前伸坐姿支架弯矩M f,st；然后使用公式(1-6)求解肢体前伸坐姿肢体弯矩M lb(见图15)：
M lb＝(G-F bd)(d lb-d fr)                  (1-6)
其中，G为患者骨折部位全下肢的重量，由计算机系统依据患者的体格因素查询知识库得到，F bd、d lb和d fr分别为本步骤测量得到的肢体侧向弯曲力、肢体总长度和骨折断端悬距。使用公式(1-7)计算得到骨痂侧向康复弯矩M b,st：
M b,st＝M lb-M f,st                   (1-7)
(c)定义骨折康复量化指标：计算机系统基于步骤六的步骤(1)建立的六轴并联骨外固定装置刚度矩阵K fx，由所述站立姿势支架力螺旋
Figure PCTCN2018102721-appb-000032
和肢体前伸坐姿支架力螺旋
Figure PCTCN2018102721-appb-000033
使用公式(1-8)分别求解六轴并联骨外固定装置两端发生的相对线变形δr和相对角变形δθ，所述的相对线变形δr和相对角变形δθ等效于骨折部位的骨痂变形量：
Figure PCTCN2018102721-appb-000034
式中K fx -1表示所述的六轴并联骨外固定装置刚度矩阵K fx的逆矩阵；由所述的相对线变形δr、相对角变形δθ、骨痂轴向康复力F b,ve和骨痂侧向康复弯矩M b,st，使用公式(1-9)计算骨痂轴向变形能E b,ve和骨痂侧向变形能E b,st：
Figure PCTCN2018102721-appb-000035
由所述的相对线变形δr、相对角变形δθ、站立姿势支架轴向力F f,ve和坐姿支架弯矩M f,st，使用公式(1-10)计算外界载荷做功W t：
Figure PCTCN2018102721-appb-000036
将所述骨痂轴向变形能E b,ve与外界载荷做功W t的比值R ve作为轴向承载性能指标，将骨痂侧向变形能E b,st与外界载荷做功W t的比值R st作为侧向承载性能指标，将所述的轴向承载性能指标R ve和侧向承载性能指标R st定义为骨折康复量化评价指标。
(d)综合量化评价骨折的愈合效果：患者每日分早、中、晚三次采取计算骨折康复二期载荷的步骤(a)至步骤(c)的方法，测算轴向承载性能指标R ve和侧向承载性能指标R st的数值；通过查询所述的骨折康复知识库信息，获得包括轴向承载性能阈值R ve,b和侧向承载性能阈值R st,b的患者骨折康复量化指标阈值。分别计算轴向承载性能指标R ve与轴向承载性能阈值R ve,b的比值λ ve、侧向承载性能指标R st与侧向承载性能阈值R st,b的比值λ st，若每日三次测得的所述比值λ ve≥85％且λ st≥85％，表示患者的骨折康复效果良好，可安全拆除六轴并联骨外固定装置；否则，需要继续携带支架进行骨折的康复，直至所测得康复量化指标符合要求。
以上对本发明的描述仅仅是示意性的，而不是限制性的，所以，本发明的实施方式并不局限于上述的具体实施方式。如果本领域的普通技术人员受其启示，在不脱离本发明宗旨和权利要求所保护范围的情况下，做出其他变化或变型，均属于本发明的保护范围。

Claims (3)

  1. 基于六轴并联骨外固定装置的骨折康复评价方法，其特征在于包括以下步骤：
    步骤一、改装六轴并联骨外固定装置：
    (1)准备六轴并联骨外固定装置的组成部件，包括近端固定环(101)、远端固定环(102)以及待连接在所述的近端固定环(101)和远端固定环(102)之间的第一支链(103)、第二支链(104)、第三支链(105)、第四支链(106)、第五支链(107)和第六支链(108)，每条支链由支链上端的第一虎克铰链(301)、支链中部的驱动丝杠(302)和支链下端第二虎克铰链(303)构成；
    (2)将六轴并联骨外固定装置的六条支链加装拉压力传感器，方法为：将所述的第一支链至第六支链的第一虎克铰链和驱动丝杠拆分，在二者之间同轴固定一个轴向力传感器；
    (3)将六个力传感器(401a)、(401b)、(401c)、(401d)、(401e)、(401f)分别通过信号线缆与一个传感信号变送设备(601)连接；
    (4)通过金属骨针及骨针连接零件，将近端固定环、远端固定环与骨折部位的近端骨块和远端骨块分别固定连接；
    (5)将加装力传感器后的第一支链至第六支链的两端分别与近端固定环和远端固定环连接；
    步骤二、调节六轴并联骨外固定装置以复位骨折畸形，步骤为：获取复位骨折畸形所需的六轴并联骨外固定装置调节方案，并按照所述的调节方案调整六条支链的长度，复位骨折畸形；完成骨折复位后，锁定六条支链的长度、固定骨折部位；
    步骤三、识别标记物及骨折骨块的空间位置：
    (1)在所述的近端固定环(101)的内圈连接孔上沿圆周方向均匀间隔安装第一标记物(701)、第二标记物(702)和第三标记物(703)，在远端固定环(102)的内圈连接孔上沿圆周方向均匀间隔安装第四标记物(704)、第五标记物(705)以及第六标记物(706)；所述的第一标记物(701)至第六标记物(706)具有相同的结构，分别包括一个标记球体(801)和连接销轴(802)；每一个所述标记物通过连接销轴下端的轴体插入近端固定环或远端固定环的内圈连接孔形成固定连接；所述的标记球体(801)使用金属材料，所述标记物销轴(802)使用塑料材料加工；
    (2)使用医学CT影像设备对患者骨折部位及六轴并联骨外固定装置进行扫描，并经过三维重建和处理后得到包括骨折近端三维实体(901)、骨折远端三维实体(902)、第一三维球体(903)、第二三维球体(904)、第三三维球体(905)、第四三维球体(906)、第五三维球体(907)和第六三维球体(908)的三维图像，并存储于所述的计算机系统中；
    (3)操作者观察计算机系统中的三维图像，并在计算机系统的软件界面中手工指定骨干的轴线(910)，然后将标记物拆除；
    步骤四、依照临床领域常用的骨折康复阶段划分方法，基于骨组织生长情况将康复阶段划分为血肿机化期、原始骨痂期和骨痂改建期三个阶段。将所述的血肿机化期和原始骨痂期称为第一时期，将所述的骨痂改建期称为第二时期；
    步骤五、患者的骨折康复处于第一时期时，按照以下步骤对六轴并联骨外固定装置进行微调，并指导患者进行康复训练：
    (1)计算六轴并联骨外固定装置的预紧载荷，步骤为：
    (a)患者采取无负重坐姿，通过六个所述的力传感器分别检测第一支链至第六支链各自承担的支链预紧力f pr,i,(i＝1～6)，然后，六个力传感器将各个支链预紧力信号通过传感信号变送器(601)无线传输至所述的计算机系统；
    (b)所述的计算机系统针对步骤三获得的三维图像，采用球面拟合算法自动识别所述的第一三维球体至第六三维球体的六个球心坐标；采用空间几何算法，分别使用第一三维球体、第二三维球体和第三三维球体的球心坐标，识别与近端固定环上表面重合的平面Puv，以近端固定环上表面的几何中心点为坐标系原点P，以原点至第一三维球体球心在平面Puv的投影点构成的矢量为坐标轴
    Figure PCTCN2018102721-appb-100001
    以过点P且平行于平面Puv法向量方向的矢量为坐标轴
    Figure PCTCN2018102721-appb-100002
    按照右手定则建立与近端固定环固定相连的近端坐标系P-uvw；分别使用第四三维球体(906)、第五三维球体(907)和第六三维球体(908)的球心坐标识别与远端固定环(102)上表面重合的平面Oxy，以远端固定环(102)上表面的几何中心点为坐标系原点O，以原点至第四三维球体(906)球心在平面Oxy的投影点构成的矢量为坐标轴
    Figure PCTCN2018102721-appb-100003
    以过点O且平行于平面Oxy法向量方向的矢量为坐标轴
    Figure PCTCN2018102721-appb-100004
    按照右手定则建立与远端固定环(102)固定相连的远端坐标系O-xyz；使用坐标系P-uvw和坐标系O-xyz确定六轴并联骨外固定装置的空间位置与姿态；
    (c)所述的计算机系统借助并联机构运动学算法，由六轴并联骨外固定装置的空间位置与姿态计算第一支链至第六支链各自的空间轴线单位矢量n i,(i＝1～6)，然后计算轴线单位矢量n i,(i＝1～6)相对于近端坐标系P-uvw原点的单位预紧力螺旋
    Figure PCTCN2018102721-appb-100005
    然后通过公式(1-1)计算得到六轴并联骨外固定装置六条支链的合力提供给所述的骨折部位近端骨块和远端骨块之间的预紧力螺旋：
    Figure PCTCN2018102721-appb-100006
    式中，f pr表示预紧力螺旋
    Figure PCTCN2018102721-appb-100007
    的线性力分量，τ pr表示预紧力螺旋
    Figure PCTCN2018102721-appb-100008
    的力偶分量。将预紧线性力螺旋的线性力分量f pr沿步骤三指定的骨干轴线方向分解，得到骨干轴向预紧力F f,pr，将所述的预紧力偶τ pr沿垂直于骨干轴线的方向分解，得到骨干侧向预紧弯矩M f,pr；
    (2)计算骨折断端承载面积：所述的计算机系统采用图形化软件界面显示步骤三中存储于计算机系统的三维图像，操作者在所述的图形化软件界面中指定骨折断面附近的骨干横截面(1201)，计算机系统采用图形学求交算法，自动识别指定骨干横截面(1201)处皮质骨对应的环状图形区域(1202)，进而计算环状图形区域(1202)对应的骨折断端承载面积S b；
    (3)计算骨折断面应力：操作者统计患者的年龄、性别、身高和体重等体格因素并输入至所述的计算机系统中，通过查询相关的骨折康复知识库信息，得到该体格因素下，有助于患者骨折愈合的许用轴向压应力σ e和许用侧向弯曲载荷M e。所述的计算机系统使用骨干轴向预紧力F f,pr和骨折断端承载截面积S b、采用公式(1-2)计算骨折断面的轴向压应力σ b：
    Figure PCTCN2018102721-appb-100009
    (4)分析骨折部位力学状况：在整个骨折康复第一时期中，计算机系统每日计算所述的骨折断面轴向压应力σ b和骨干侧向预紧弯矩M f,pr，分别与所述的知识库提供的许用轴向压应力σ e和许用侧向弯曲载荷M e比较，若患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内，并且患者的骨折断面的侧向预紧弯矩M f,pr与知识库的许用侧向弯曲载荷M e的比值小于120％，则保持该压应力σ b和侧向预紧弯矩M f,pr，然后进行步骤五中的步骤(6)；否则，进行步骤五中的步骤(5)；
    (5)优化患者的康复策略：若所述的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值大于120％，每次将第一支链(103)至第六支链(108)的长度同步伸长0.5mm，然后重复步骤五中的步骤(1)、(3)计算轴向压应力σ b，直至患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内方可停止伸长支链的长度；若所述的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值小于60％，每次将第一支链(103)至第六支链(108)的长度同步缩短0.5mm，然后重复步骤五中的步骤(1)、(3)计算轴向压应力σ b，直至患者的骨折断面轴向压应力σ b与许用轴向压应力σ e的比值在60％～120％范围内方可停止缩短支链的长度；
    若所述侧向预紧弯矩M f,pr与许用侧向弯曲载荷M e的比值大于120％，则每次将伸长弯矩方向内侧 支链的长度伸长0.5mm、同时将弯矩方向外侧支链的长度缩短0.5mm，然后重复步骤五中的步骤(1)计算侧向预紧弯矩M f,pr，直至患者的骨折断面的侧向预紧弯矩M f,pr与知识库的许用侧向弯曲载荷M e的比值小于120％方可停止调节支链的长度；
    (6)在每日重复步骤五中的步骤(3)评价断面力学状况的同时，计算机系统分析患者最近5日的骨折断面力学状况的变化情况，并向患者提供康复训练运动量的调整建议：若骨折断面的每日轴向压应力σ b相较前一日不断降低且累计降低幅度大于15％，则向患者建议适当进行一些站立及行走的活动；若骨折断面的轴向压应力σ b每日相较前一日不断增加且累计增加幅度超出15％，则向患者建议适当减少站立及行走的活动；若骨折断面的轴向压应力σ b在五日内变化幅度不超过15％，则患者的康复训练运动量较为合理，保持该运动量促进骨折的康复；
    (7)根据临床的经验，当患者骨折断端的骨痂生长充分后，拍摄骨痂的X射线影像并加以分析，患者是否完成骨折康复第一时期的愈合；
    步骤六、患者骨折康复处于第二时期时，采用如下步骤选择合适的时机拆除六轴并联骨外固定装置、完成骨折康复：
    (1)建立六轴并联骨外固定装置刚度模型：将所述的六轴并联骨外固定装置划分为金属骨针子系统、固定环子系统和支链子系统，分别建立各个子系统的刚度矩阵；所述的计算机系统依据步骤五获得的六轴并联骨外固定装置的空间位置与姿态，确定各所述子系统的空间相对关系，然后基于虚功原理和变形叠加原理将各所述子系统的刚度矩阵线性叠加，建立以刚度矩阵K fx描述的六轴并联骨外固定装置刚度模型；
    (2)计算骨折康复二期载荷，步骤为：
    (a)检测肢体轴向载荷，患者采取站立姿势，使用患肢底部布置的电子称量设备(1401)检测肢体轴向压力F lb，操作者将所述的轴向压力F lb输入计算机系统；通过六个力传感器分别检测站立姿势六轴并联骨外固定装置各支链的轴向力f ve,i,(i＝1～6)，六个力传感器然后将站立姿势下各个支链的轴向力信号通过传感信号变送器传输至计算机系统，根据公式(1-3)计算六轴并联骨外固定装置承担的站立姿势支架力螺旋：
    Figure PCTCN2018102721-appb-100010
    式(1-3)中f ve和τ ve分别表示站立姿势支架力螺旋
    Figure PCTCN2018102721-appb-100011
    的线性力分量和力偶分量；计算机系统将所述的站立姿势支架力螺旋的线性力分量f ve沿骨干轴线的方向分解，得到站立姿势支架轴向力F f,ve；然后 采用公式(1-4)计算得到骨折部位承担的骨痂轴向康复力F b,ve：
    F b,ve＝F lb-F f,ve  (1-4)
    (b)检测肢体侧向载荷，步骤为：患者采取骨折肢体前伸的坐姿，使用布置在骨折肢体足底的电子称量设备(1401)检测肢体侧向弯曲力F bd，同时使用尺测量肢体从臀部与座椅支撑点至足底与电子称量设备(1401)支撑点之间的总长度d lb、以及从骨折断端至足底与电子称量设备(1401)支撑点之间的骨折断端悬距d fr，操作者将上述数据输入至计算机系统；通过六个力传感器分别检测六轴并联骨外固定装置各支链的轴向力f st,i,(i＝1～6)，六个力传感器然后将肢体前伸坐姿下各个支链的轴向力信号通过传感信号变送器(601)传输至计算机系统，根据公式(1-5)计算六轴并联骨外固定装置承担的肢体前伸坐姿支架力螺旋：
    Figure PCTCN2018102721-appb-100012
    式(1-5)中f st和τ st分别表示肢体前伸坐姿支架力螺旋
    Figure PCTCN2018102721-appb-100013
    的线性力分量和力偶分量；计算机系统将所述的肢体前伸坐姿支架力螺旋的力偶分量τ st沿垂直于骨干轴线的方向分解，得到肢体前伸坐姿支架弯矩M f,st；然后使用以下表达式求解肢体前伸坐姿肢体弯矩M lb：
    M lb＝(G-F bd)(d lb-d fr)  (1-6)
    其中，G为患者骨折部位全下肢的重量，由计算机系统依据患者的体格因素查询知识库得到，F bd、d lb和d fr分别为本步骤测量得到的肢体侧向弯曲力、肢体总长度和骨折断端悬距；使用公式(1-7)计算得到骨痂侧向康复弯矩M b,st：
    M b,st＝M lb-M f,st  (1-7)
    (c)定义骨折康复量化指标：计算机系统基于步骤六的步骤(1)建立的六轴并联骨外固定装置刚度矩阵K fx，由所述站立姿势支架力螺旋
    Figure PCTCN2018102721-appb-100014
    和肢体前伸坐姿支架力螺旋
    Figure PCTCN2018102721-appb-100015
    使用公式(1-8)分别求解六轴并联骨外固定装置两端发生的相对线变形δr和相对角变形δθ，所述的相对线变形δr和相对角变形δθ等效于骨折部位的骨痂变形量：
    Figure PCTCN2018102721-appb-100016
    式中K fx -1表示所述的六轴并联骨外固定装置刚度矩阵K fx的逆矩阵；由所述的相对线变形δr、相对角 变形δθ、骨痂轴向康复力F b,ve和骨痂侧向康复弯矩M b,st，使用公式(1-9)计算骨痂轴向变形能E b,ve和骨痂侧向变形能E b,st：
    Figure PCTCN2018102721-appb-100017
    由所述的相对线变形δr、相对角变形δθ、站立姿势支架轴向力F f,ve和前伸姿势支架弯矩M f,st，使用公式(1-10)计算外界载荷做功W t：
    Figure PCTCN2018102721-appb-100018
    将所述骨痂轴向变形能E b,ve与外界载荷做功W t的比值R ve作为轴向承载性能指标，将骨痂侧向变形能E b,st与外界载荷做功W t的比值R st作为侧向承载性能指标，将所述的轴向承载性能指标R ve和侧向承载性能指标R st定义为骨折康复量化评价指标；
    (d)综合量化评价骨折的愈合效果：患者每日分早、中、晚三次采取步骤(a)至步骤(c)的方法，测算轴向承载性能指标R ve和侧向承载性能指标R st的数值；通过查询所述的骨折康复知识库信息，获得包括轴向承载性能阈值R ve,b和侧向承载性能阈值R st,b的患者骨折康复量化指标阈值。分别计算轴向承载性能指标R ve与轴向承载性能阈值R ve,b的比值λ ve、侧向承载性能指标R st与侧向承载性能阈值R st,b的比值λ st，若每日三次测得的所述比值λ ve≥85％且λ st≥85％，表示患者的骨折康复效果良好，可安全拆除六轴并联骨外固定装置；否则，需要继续携带支架进行骨折的康复，直至所测得康复量化指标符合要求。
  2. 根据权利要求1所述的基于六轴并联骨外固定装置的骨折康复评价方法，其特征在于：采用圆柱型轴向力传感器加装于所述的六条支链中。
  3. 根据权利要求1或者2所述的基于六轴并联骨外固定装置的骨折康复评价方法，其特征在于：所述的传感信号变送器传输至所述的计算机系统中的信号通过蓝牙协议无线传输。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113925584A (zh) * 2021-10-22 2022-01-14 山西昱一文化发展有限公司 一种电子骨外固定器的数字控制系统

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109965962A (zh) * 2019-05-09 2019-07-05 吴旭华 一种骨科外固定支架
CN110801230A (zh) * 2019-10-10 2020-02-18 西安理工大学 一种针对下肢骨折康复效果的评价方法
CN111481280B (zh) * 2020-04-22 2021-03-02 北京工业大学 一种用于长骨畸形矫正的y型支链外固定器
CN111685880B (zh) 2020-05-18 2021-08-31 天津大学 可穿戴式骨折复位与康复一体化机器人
CN112370153B (zh) * 2020-11-13 2022-03-11 山东中医药大学 面向四肢骨折的一体化手术系统及控制方法
CN112370171B (zh) * 2020-11-13 2022-05-24 山东中医药大学附属医院 一种带有标定的并联万向夹持装置及其使用方法
CN112245005B (zh) * 2020-11-13 2022-04-29 山东大学 一种用于坐标标定的外固定装置、系统及方法
CN112999031B (zh) * 2021-03-11 2022-07-01 国家康复辅具研究中心 一种基于具有力感知并联机构的骨盆支撑助行器
CN113576661B (zh) * 2021-08-03 2023-07-14 天津大学 面向骨折手术机器人的踝关节骨折术后早期量化康复方法
CN113907882A (zh) * 2021-08-26 2022-01-11 四川大学华西医院 一种用于骨折手术的复位定位机器人
CN114732522B (zh) * 2022-03-14 2024-05-14 天津大学 柔性丝驱动骨折复位手术机器人

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3802743A1 (de) * 1988-01-30 1989-08-03 Baehr Geb Green Judith M Vorrichtung zur externen fixation und reposition von knochenfragmenten
CN1073353A (zh) * 1991-12-13 1993-06-23 刘维胜 长骨干万能复位固定器
GB9403158D0 (en) * 1994-02-18 1994-04-06 Draper Edward R C Medical apparatus
US5437668A (en) * 1994-02-18 1995-08-01 Board Of Trustees Of The University Of Ark. Apparatus and method for clinical use of load measurement in distraction osteogenesis
GB2290615B (en) * 1994-06-20 1998-07-08 James Bruce Richardson System for measuring stiffness of a fractured bone
US5728095A (en) * 1995-03-01 1998-03-17 Smith & Nephew, Inc. Method of using an orthopaedic fixation device
US6030386A (en) * 1998-08-10 2000-02-29 Smith & Nephew, Inc. Six axis external fixator strut
EP1217960A1 (en) * 1999-09-28 2002-07-03 Kristian G. Bundgard Method of measuring bone strength, apparatus for measuring bone strength and fixation device
EP2240085A4 (en) * 2008-02-08 2014-01-01 Texas Scottish Rite Hospital EXTERNAL FIXIERSTREBE
CN101474090B (zh) * 2009-02-17 2010-12-08 哈尔滨工业大学 六自由度穿戴式辅助接骨并联机器人
US20110313419A1 (en) * 2010-06-22 2011-12-22 Extraortho, Inc. Hexapod External Fixation System with Collapsing Connectors
EP2723270B1 (en) * 2011-06-27 2019-01-23 Board of Regents of the University of Nebraska On-board tool tracking system of computer assisted surgery
US9498231B2 (en) * 2011-06-27 2016-11-22 Board Of Regents Of The University Of Nebraska On-board tool tracking system and methods of computer assisted surgery
US20130041288A1 (en) * 2011-08-08 2013-02-14 John Charles Taylor Apparatus and Method of Monitoring Healing and/or Assessing Mechanical Stiffness of a Bone Fracture Site or the Like
CN202365897U (zh) * 2011-10-27 2012-08-08 天津市新中医疗器械有限公司 三维空间外固定架
WO2013116812A1 (en) * 2012-02-03 2013-08-08 Orthohub, Inc. External fixator deformity correction systems and methods
CN104398295B (zh) * 2013-12-05 2017-03-08 乔锋 一种骨科畸形矫正与骨折复位固定装置及其加工方法
US9289238B2 (en) * 2014-04-23 2016-03-22 Texas Scottish Rite Hospital For Children Dynamization module for external fixation strut
WO2016024184A1 (en) * 2014-08-14 2016-02-18 Automobili Lamborghini S.P.A. Device for external orthopedic fixations
JP6556247B2 (ja) * 2015-04-03 2019-08-07 アカリー，イブラヒム デニズＡＫＣＡＬＩ，Ｉｂｒａｈｉｍ Ｄｅｎｉｚ ラムダ型固定装置
CN205586060U (zh) * 2016-03-16 2016-09-21 大博医疗科技股份有限公司 一种三维固定支架及具有该支架的骨骼外固定架
CN206228410U (zh) * 2016-07-01 2017-06-09 河北工业大学 一种基于磁致伸缩的泰勒架骨康复机构

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113925584A (zh) * 2021-10-22 2022-01-14 山西昱一文化发展有限公司 一种电子骨外固定器的数字控制系统

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