Background technology
Modern medical diagnosis and treatment technology and scientific and technological revolution closely bound up.Since X-ray finds, doctor has been enable to understand space structure and the metamorphosis of live body skeletal tissue by lonizing radiation.Start to 20 century 70s, CT scan technology allow doctor can and the organizational structure of each thin layer of Accurate Analysis human body.To the nineties, by the computer digit process in later stage, can the three dimensions of virtual organization structure, the form with two-dimension picture on CT sheet or computer represents.But along with the development of 3D printing technique, at present for the 3D solid reproduction reproduction of organizational structure provides technical foundation.
1984, Charles invention stereolithograghy technology, was proposed first item 3D printer in the world; Within 2010, Oraganovo company of the U.S. releases First biometric print machine in the world, patients own cells can be utilized to carry out design and print.Within 2012, Dutch scientist's the first uses 3D printing technique, completes the mandibular bone transplant operation of 83 years old women.Although 3D printing technique can play huge advantage in curative activity and life science work, above technology application is only confined to external large-scale scientific research institution, cannot popularize in each medical institutions of China and medical science institutes.
The demand of a large amount of physical models is had in clinical and research work.Anatomic form due to skeleton is three-dimensional, medical science is rebuild be difficult to complete smoothly in art, current 3D prints the using value of rapid shaping technique in defect and restore and gains public acceptance, it can auxiliary diagnosis disease, develop programs, sham operated, minimizing wound, greatly improve accuracy rate of diagnosis and performance accuracy.For Oral and Maxillofacial Surgery, Jaw neoplasm excision or fracture patient, need titanium or Absorbable rod plate to complete reconstruction, but all kinds of dieplate of unified specification or blade plate do not possess three-D space structure, on operating-table, normally complete structure preparation.Conventional method can delay a large amount for the treatment of times, increases the amount of bleeding in operation in patients and drug use amount.If the Cranial defect situation after injury in traumatic condition of patient or treatment can be copied before surgery in advance, take the preformed Therapeutic Method of implant, greatly will improve the therapeutic efficiency of patient.
Current China fracture or bone tumor operation adopt the technology of implant molding in art usually, extend operating time, cannot reach the precise forming of implant, and add the work difficulty of doctor.Patient's amount of bleeding in the middle of operation process is increased, and reduction of the fracture effect is bad, brings a large amount of post-operative complication.By technique, can overcome the above problems very well, promote medical development progress.
Summary of the invention
The object of the present invention is to provide a kind of preoperative preformed method of skeletal fixation plate based on 3D printer model, for solving following problems, skeleton tissue is that a class has three-D space structure sclerous tissues, in patient's wound or tumor therapeutic procedure, require that doctor utilizes metal fixing plate to fix bone stump, with complete skeletogenous seriality.Due to the individuality difference of skeleton, logical meeting carry out molding in the middle of operation process, extends operating time, increases corrective surgery amount of bleeding.And due to wound expose difficulty, cause the molding of fixing head bad, make the accuracy of operation and therapeutic effect undesirable.
In order to overcome the above problems, the technical solution used in the present invention is as follows, and a kind of preoperative preformed method of skeletal fixation plate based on 3D printer model, comprises the following steps: obtain human body CT scan data; According to tissue optical density value difference, utilize open Medical Imaging software to complete skeleton data and obtain and complete skeleton virtual operation; Export STL form to print to 3D printer, use poly-lactic acid material to melt the fine printing type increasing material, obtain skeleton model; Adopt titanium plate pre-shaped tool, complete skeletal fixation sheet metal forming according to model.
As preferably, it is characterized in that, obtain human body CT scan DICOM data concrete steps as follows: the thin-layer CT or the MRI that gather patient check the Digital imaging in medicine normal data generated; CT or MRI Scan slice thickness is less than or equal to 2mm; Use software typing DICOM data.
As preferably, it is characterized in that, complete skeletal fixation sheet metal forming concrete grammar according to model as follows: utilize the postoperative skeleton model of preparation as implant preforming source, implant is positioned over model surface; Use moulding folder, be fixed pressurization according to important instrument of skeleton anatomical structure, and the adjustment completing implant xyz tri-directions is moulding; Fixedly spend the night, remove metal Memorability.
Beneficial effect of the present invention is as follows:
The present invention, based on existing public data process software, the DICOM data of conversion CT, application 3D printing technique makes personalized skeleton model, thus enable the data of patient strictly according to the facts complete physical replication.Appliance computer virtual operation skill again, can recover the normal configuration of skeleton, thus makes the three dimensional structure after fracture or bone tumor para-position.Based on made postoperative model, adopt the pre-shaped tool that series is special, complete the preforming of implanting fixing head.Thus saving surgical time, improve operation precision.
Embodiment:
Step 1: data inputting:
1.1 data acquisitions: in the radiology department of medical institutions, the thin-layer CT or the MRI that gather patient check the Digital imaging in medicine normal data generated, Digitalimagingandcommunicationsinmedicine, DICOM3.0 data;
The screening of 1.2 data:
1.2.1 because scan-data determines output model result, the highest output accuracy of the inventive method is thickness 0.1mm, therefore advises CT or MRI Scan slice thickness < or=2mm;
1.2.2 found by scale-model investigation, the inventive method maximum printable precision is 0.1mm, and therefore lower than the organizational structure of 0.1mm, such as the structural research such as nasal sinuses or paranasal sinuses is not suitable for the present invention;
1.2.3 because printing setting scope of the present invention is 150 × 150 × 240mm, therefore research category should be less than this volume;
1.3 use Mimics software typing DICOM data: the importimages instrument using file hurdle, open the DICOM data collected, according to conditions of patients or research needs, choose the DICOM data that institute needs, complete data input, confirm the 3 D stereo direction of model, be converted into study model.
Step 2: date processing:
2.1 make skeleton mathematical model:
2.1.1 threshold value limits: carry out anatomical structure division according to Bone (CT) or Bone (MRI) gray value threshold value.Human body CT gray value has reacted the decay size of material to x-ray, and the gray value of water is defined as 0, and the CT value of fat is-100, and cortical bone density is 2000, is therefore imaged as example with CT skeleton, and choose bonescale scope, gray value is between 226-3071.And the sclerous tissues CT value scopes such as spongy bone, cortical bone and tooth can be screened according to correlation coefficient, generate the eyelid covering file of selection area.
2.1.23D computing: use the Medical Imaging softwares such as mimics to complete the three-dimensional reconstruction of figure, in view of 3D print data output accuracy of the present invention is usually above data inputting precision, custom option is selected in quality, need to set options such as slices and smothing according to model, the digital three-dimensional structure of computing generation model.
2.2 model areas limit:
2.2.1 three dimensions limits: after generating skeleton three-dimensional digital model, at the Coronal of software, horizontal position and sagittal plain three windows dilatory scale respectively, frame selects the region studied, and the eyelid covering file simultaneously repeatedly after computing selected parts, generates new three-dimensional digital model.
2.2.2 organizational structure is separated: because the three dimensional structure of skeleton has scrambling, software tool can not be separated associated bone completely, therefore must carry out further model separation according to skeleton profile.According to the Coronal of data, horizontal position and sagittal plain three different aspects, carry out choosing or removing of associated bone, complete the skeleton that will print and be separated with around sclerous tissues, generate new eyelid covering file, again complete three-dimensional reconstruction computing, generate new mathematical model.
2.3 models prepare before printing:
2.3.1STL file output: after completing the foundation of skeleton three-dimensional digital model, export the stl file format of target skeleton or tissue, be saved in object file;
2.3.2STL file translations: stl file imports model slice as figure, the Makeware software of such as Maker-bot company sets the locus of printer model, direction of rotation and convergent-divergent size, avoids the zoom function regulating model.
2.3.2.1 model space position: be set as MovetoPlatform, by model as the printing that panel can reduce support, saves printed material;
2.3.2.2 direction of rotation: owing to generation model pillar in space Z-direction in 3D print procedure, Z-direction printing precision is the poorest simultaneously, rotating model reduces pillar can save printed material, improves printing precision.
2.3.2.3 convergent-divergent size: for ensureing the accuracy of model, model should keep original size.
Step 3: model prints:
3.1 hardware are purchased: use existing molten fine printer, the thereplicator2 desktop printer that such as U.S. Makerbot company produces, and supporting polylactic acid (PLA) printed material.
3.2 hardware installations: be arranged on fixing desktop by printer according to operation instructions, avoid rocking.Connect power supply, leveling and test are carried out to printer.
3.3 mimeograph documents inputs: usage data line is connected with computer, after installing usb port, application makerware software directly prints; Or input x3g file is to SD card, inserts printer and selects FromSDcard off-line printing.
3.4 print: print erecting of panel protecting film, require pre-thermal printer to 230 DEG C (fusing point of PLA material) according to printer description, add PLA material, and the fine mode printed is melted in application, printed design skeleton model.
Step 4: model post-processed:
4.1 model pillar process: take out model, application machine strength removes unnecessary corbeling, avoids damage model itself simultaneously.At the pillar of model inside, can first with 10% NaOH solution infiltrate 30 seconds after again row machinery remove.
4.2 model polishings: utilize the NaOH solution wiping of 10%, chemolysis completes the surface finish of model, tap water cleans; Or using acetylene burner to dissolve model surface PLA pillar remains.
Step 5: implant shaping technology:
5.1 utilize the postoperative skeleton model of preparation as implant preforming source, and need implant site according to operation, implant is positioned over model surface, it is moulding clamping fixed to use;
5.2 use moulding folder, be fixed pressurization, and the adjustment completing implant xyz tri-directions are moulding according to important instrument of skeleton anatomical structure;
5.3 fixedly spend the night, and remove the metal Memorability of implant.