The Monte Carlo N-Particle (MCNP) is often used to calculate the radiation dose during computed tomography (CT) scans. However, the physical calculation process of the model is complicated, the input file structure of the program is complex, and the three-dimensional (3D) display of the geometric model is not supported, so that the researchers cannot establish an accurate CT radiation system model, which affects the accuracy of the dose calculation results. Aiming at these two problems, this study designed a software that visualized CT modeling and automatically generated input files. In terms of model calculation, the theoretical basis was based on the integration of CT modeling improvement schemes of major researchers. For 3D model visualization, LabVIEW was used as the new development platform, constructive solid geometry (CSG) was used as the algorithm principle, and the introduction of editing of MCNP input files was used to visualize CT geometry modeling. Compared with a CT model established by a recent study, the root mean square error between the results simulated by this visual CT modeling software and the actual measurement was smaller. In conclusion, the proposed CT visualization modeling software can not only help researchers to obtain an accurate CT radiation system model, but also provide a new research idea for the geometric modeling visualization method of MCNP.
Radiation Dosage ; Software Design ; Tomography, X-Ray Computed/methods* ; Software ; Algorithms ; Phantoms, Imaging ; Monte Carlo Method

Objective: To investigate the trueness of 4 three-dimensional (3D) facial scanners and to evaluate the applicability of their clinical use. Methods: An art head model was used as the scanning object, and it was scanned by Handyscan 3D scanner in an enclosed environment with a fixed light source to obtain the reference digital model. Three fixed 3D facial scanners (A: 3dMDface; B: Facego Pro; C: RDS Facescan) and a portable hand-held 3D facial scanner (D: Revopoint POP 2) were used to scan the art head model 10 times, and 10 models of each scan group were obtained. The face of the reference model was divided into 16 regions according to anatomy and muscle distributions in the Geomagic Wrap software with saved boundary curves of whole face and each region. The test models were also divided into 16 regions through the curves above after registered with the reference model through "Best fit" function. The root-mean-square error (RMS) of the complete test models and their segmented regions compared with the reference model and its corresponding regions were calculated by 3D comparison function. The smaller the RMS, the higher the accuracy. One-way ANOVA and SNK post-test were used for statistical analysis. Results: RMS of complete test models scanned by A, B, C, D scanners were (0.295±0.005), (0.216±0.053), (0.059±0.012) and (0.103±0.026) mm (F=123.81, P<0.001), respectively. There was significant difference between any two groups (P<0.05). For each facial region, the group D had the best trueness in nasal region, lip region, left orbital region and right orbital region [RMS were (0.079±0.032), (0.061±0.019), (0.058±0.021), (0.081±0.032) mm, respectively], while the group C had the best trueness in frontal region, left buccal region, right buccal region, left zygomatic region, right zygomatic region, left parotideomasseteric region, right parotideomasseteric region, left temporofacial region, right temporofacial region, mental region, left infraorbital region and right infraorbital region [RMS were (0.039±0.011), (0.034±0.007), (0.033±0.007), (0.066±0.023), (0.038±0.022), (0.070±0.030), (0.067±0.024), (0.063±0.029), (0.045±0.023), (0.063±0.006), (0.039±0.010), (0.046±0.008) mm, respectively]. Conclusions: On the basis of art head model scanning, although the overall average deviation between the scanning model and the reference models obtained by the four kinds of 3D facial scanners were small, the portable handheld 3D facial scanner (D) has better accuracy than the fixed 3D facial scanners (A, B, C) in the orbital area, nasal area, lip area and areas with rich features.
Computer-Aided Design ; Imaging, Three-Dimensional ; Software ; Dental Impression Technique

In order to improve the operation difficulties in the narrow space of the nasal maxillary sinus, the nasal continuum minimally invasive surgical robot system is designed. The ball-and-socket joints and NiTiNol tubes are used as the main body of the continuum structure to improve the degree of freedom. The hardware systems and software systems are designed. The security control policies are planned. Finally, the robot confirmed prototype experiments are conducted and the feasibility of continuum robot confirmed through master-slave control experiment and animal experiment.
Animals ; Biomechanical Phenomena ; Equipment Design ; Minimally Invasive Surgical Procedures ; Robotic Surgical Procedures ; Robotics ; Software

OBJECTIVE: To explore the construction process of the digital reference crown models, and to initially establish the digital reference crown models of the primary teeth to lay the foundation for the establishment of the standardized crown models and the future related applications of computer-aided design/computer-aided manufacture (CAD/CAM) technology to pediatric dentistry. METHODS: This study randomly selected children who were caries free, aged from 4 to 5 years in several kindergartens of Haidian District of Beijing.Plaster dental models were made for the children after taking complete impressions.The digital dental models were reconstructed by using the three-dimensional (3D) dental model scanner.And then, Geomagic Studio, a 3D reverse engineering software, was employed to extract the single dental crown data, the mesiodistal and buccolingual diameters and the height of the crowns were measured.The object was reduced or enlarged by a numerical factor, and then the size of each dental crown was standardized.A total of 3-5 points features on the crown were created, and all the objects were aligned through the functions of feature-based alignment.Finally, through average-based object creation and smoothing, the digital models of reference crowns of the primary teeth were established. RESULTS: A total of 40 plaster dental models from 16 boys and 26 girls were selected out for our further study.The digital dental models were reconstructed, and the mesiodistal and buccolingual diameters and the height of the crowns were measured by using reverse engineering technology.Comparing the results of using mesiodistal diameter, buccolingual diameter and height as the standards, we chose the mesiodistal diameters of crowns to do the standardization, and successfully established the digital reference models of 20 primary teeth crowns with detailed surface characteristics. CONCLUSION In this study, the digital reference crown models of the primary teeth were established by reverse engineering technology, providing reference value for the standardized crown models and application for clinical practice, scientific research and teaching.Furthermore, this study also contributes to the extensive application of CAD/CAM technology in pediatric dentistry and the development of CAD/CAM dental systems with independent intellectual property rights.
Child ; Computer-Aided Design ; Crowns ; Dental Prosthesis Design ; Female ; Humans ; Male ; Software ; Tooth Crown ; Tooth, Deciduous

Aiming at the current situation of performance testing of hemodialysis extracorporeal circulation tubing, which has slow efficiency, inaccurate measurement, and inconvenient testing, a portable detection system for testing the performance of hemodialysis extracorporeal circulation tubing is designed. The system mainly includes a hardware system and a software system. The hardware system uses STM32F407 single-chip microcomputer as the core to design the driving control of the roller pump; the software system uses the C++ real-time operating system, and the flow detection data is transmitted to the upper computer through RS485 communication and displayed. Experimental showed that the system detects the accuracy and the stability of the flow rate. It has the characteristics of stability and high precision. The relative error of the experimental measurement is within the range of ±10%. The weight of the whole machine is 2 kg, which improves the efficiency by 50% compared with the traditional detection method.
Computers ; Equipment Design ; Extracorporeal Circulation ; Microcomputers ; Renal Dialysis ; Software

Aiming at the low efficiency and low quality detection level of the manual infusion set, a gas detection system for infusion set based on STM32 single-chip microcomputer was designed. The detection system includes hardware system design and software system design. The hardware system is based on the STM32F103 single-chip microcomputer. It mainly designs the gas pressure sensor acquisition circuit and the multi-way solenoid valve control circuit. The software system uses a C ++ real-time operating system to ensure system monitoring's real-time performance and validity. Test data is transmitted to the upper computer and displayed via USB serial communication. The experiment proves that the infusion set gas detection system can perform gas detection on the infusion set. The system has the characteristics of stability and high accuracy. The relative error of the experimental measurement is within ±5%, and the detection efficiency is better than manual detection.
Computers ; Equipment Design ; Microcomputers ; Software

This study established a rapid ECG screening system through the application of wearable ECG equipment. The closed-loop and self-service process of ECG inspection, data collection, transmission and printing have been realized. The new rapid ECG screening system docking with HIS system in the hospital, forming a new intelligent mode of rapid ECG screening. This paper introduces the design of the intelligent mode of ECG rapid screening from the aspects of hardware, software, wearable ECG examination equipment, and briefly describes its implementation path and technical scheme. With the rapid ECG screening system, human power can be saved, the timeliness of ECG examination can be enhanced. The level of ECG diagnosis in the basic units can be improved through building a multiple medical centers which is rely on the cloud platform.
Electrocardiography ; Equipment Design ; Humans ; Research ; Software ; Wearable Electronic Devices

OBJECTIVE: To establish a method for the production of digital individual tooth tray based on three-dimensional (3D) scan, computer-aided design (CAD) and 3D printing, and to evaluate the effect of impression taking of full-arch crown abutments by digital individual tooth tray technique and conventional method through in vitro study. METHODS: The full crown preparation was performed on all the fourteen resin teeth in a standard model of mandibular dentition. The surface data of prepared abutments was collected by 3D scanning. A new project was created in a dental CAD software including all the fourteen teeth in the mandibular dentition. The design modules of anatomy crown and coping were selected for each tooth. The dentition was divided for three sections: right posterior teeth, anterior teeth, and left posterior teeth areas. The connector design was added between the abutments within the same section. The scanned data of the abutments were imported. The occlusal plane and insertion path were determined. The position of margin line, as well as the shape of anatomy crown and connector as the main body of the individual tooth tray were designed for each abutment. The shape of coping was generated as the space for holding the impression material. The finalized data of the main body was imported into Geomagic software. The retentive attachment was added at the external surface and the tissue stop was formed at the internal surface. The completed individual tooth tray was manufactured by 3D printing with resin material. The data of full-arch crown abutments were modified and printed. The conventional dentition trays A and B, as well as digital individual tooth tray were designed and printed for four copies each. The polyether impressions of the full-arch abutments were made by conventional one-step method using dentition tray A, and by sectional-impression technique using digital individual tooth tray and dentition tray B for four times each. The time spent for each impression taking and the numbers of defects at the shoulder and axial/occlusal surface in each impression were recorded. The impression quality of each abutment was evaluated. The overall quality distribution and the pass rate of abutments between the two methods were analyzed. RESULTS: The impressions made by conventional method had more defects at shoulder than those made by digital individual tooth tray technique. No difference of the number of defects at axial/occlusal surface between the two methods was observed. The digital individual tooth tray technique for the full-arch abutment impression exhibited higher pass rate of abutments and better quality of impression, compared with conventional methods. CONCLUSION A new method for the production of digital individual tooth tray based on digital scanning, CAD and 3D printing was established. Compared with conventional method, using digital individual tooth tray technique for impression taking of full-arch abutments can achieve better effect.
Computer-Aided Design ; Crowns ; Dental Impression Materials ; Dental Impression Technique ; Models, Dental ; Printing, Three-Dimensional ; Software

OBJECTIVE: To establish the workflow of determining the jaw position of repositioning splint with the aid of digital technique, and to evaluate the accuracy of this workflow and compare the accuracy of raising different vertical dimensions in vitro. METHODS: A volunteer was recruited. The data of full-arch scans, cone beam computed tomography (CBCT) image and ultrasonic jaw motion tracking of the volunteer were acquired. The full-arch scans were merged with the CBCT image, which were then matched to the jaw motion tracking reference system. The jaw position of repositioning splint was determined when the anterior teeth opening was 3 mm and the condyle was in centric relation of the fossa in the sagittal plane. A digital repositioning splint was designed in the software based on virtual articulator and fabricated with additive manufacturing technique. After the splint was tried in, another CBCT image was taken and a qualitative analysis was conducted to compare the position of condyle between these two CBCT images. In the in vitro study, standard dental plaster casts with resin ball markers attached to the base were mounted onto a fully adjustable articulator in the intercuspal position. The dental casts were scanned by an extraoral scanner to establish digital models. The ultrasonic jaw motion tracking device was used to obtain simulated jaw movements on the articulator, which was repeated for three times. The digital models and data of jaw movements were merged in one coordination with the aid of bite forks. The jaw position of repositioning splint was determined by adjusting data of jaw movements, each of which was used to determine three vertical jaw positions 4 mm, 5 mm, and 6 mm with the horizontal jaw position of protrusion 2 mm. The virtual articulators with differently adjusted jaw movements were applied in designing repositioning splints, and the final repositioning splints and virtual jaw relationships were exported in STL format. Then the repositioning splints were fabricated with additive manufacturing technique and tried in plaster casts on the mechanical articulator, which were scanned and the jaw relationships on the mechanical articulator were exported later. The virtual jaw relationships and scanned jaw relationships were registered according to lower models and displacement of upper models was calculated. Ball markers were fit to acquire the coordinates of centers and absolute difference values of centers along three coordinating axes X, Y, and Z were calculated. One-way analysis of variance was conducted using SPSS 18.0 software to compare deviations of the three different vertical jaw relationships in two-side test and the significance level was 0.05. RESULTS: With the aid of multi-source data fusion and individualized jaw motion, the clinical workflow of determining jaw position of repositioning splint was preliminarily established. The designed jaw position was realized on the right and the condyle was more inferior than the designed position on the left. Both displacement of the upper models and absolute difference values of centers showed no significant differences (P>0.05) in different vertical jaw dimensions. The displacement of the upper models was (0.25±0.04) mm. The absolute difference values of centers along the three coordinating axes X, Y, and Z were respectively (0.08±0.01) mm, (0.30±0.02) mm, and (0.21±0.04) mm. CONCLUSION A novel method of determining the jaw position of repositioning splint with the aid of digital technique is established. It is proved to be feasible by try-in after multi-data fusion, computer-aided design and computer-aided manufacturing. As is shown in vitro, it is accurate to apply this method in adjusting jaw position. Further clinical trial will be designed to evaluate its clinical effect.
Computer-Aided Design ; Cone-Beam Computed Tomography ; Dental Articulators ; Humans ; Jaw Relation Record ; Occlusal Splints ; Software ; Splints

OBJECTIVE: To investigate the factors affecting the trueness of finish lines of full crown preparations in digital impressions. METHODS: A full crown preparation of the right maxillary molar was prepared on the standard resin dentition model, the trueness of the finish lines, the full crown preparation in the whole dentition and the isolated full crown preparation were measured respectively. Detection of scanning trueness of the finish lines of the full crown preparation in the whole dentition: (1) Using Imetric scanner to scan the full crown preparation, obtaining STL (Stereo lithographic) format data as the reference true value; (2) Using CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner to scan the full crown preparation, obtaining all the STL format data, import Geomagic Studio 2013 software, extraction of images and data of the complete finish lines or local finish lines (mesial, distal, buccal, lingual) of the full crown preparation, then using the data to 3D Compare Analysis with the reference true value, outputting RMS (root mean square) values which could evaluate the scanning trueness, the lower RMS value was, the lower the trueness was. The detection of scanning trueness of the finish lines of the isolated full crown preparation: (1) the anterior and posterior adjacent teeth of the preparation were removed to establish the model of the isolated full crown preparation; (2) CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner were used to scan the isolated preparations, and each group was repeated 6 times. Data collection and analysis were the same as the first part, that is, detection of scanning trueness of finish lines of the full crown preparation in the whole dentition. RESULTS: In the whole dentition, (1) the RMS value [(44±7) μm] of CEREC Omnicam oral scanner scanning complete finish lines was greater than that of 3Shape TRIOS oral scanner [(35±6) μm](P < 0.05). (2) the RMS values of the mesial [(45±9) μm], buccal [(38±3) μm] and lingual [(40±3) μm] finish lines in CEREC Omnicam oral scanner scanning were all lower than that in distal [(63±7) μm](P < 0.05), and the RMS values in mesial were higher than that in buccal and lingual (P>0.05). The RMS values of 3Shape TRIOS oral scanner scanning mesial and distal finish lines were significantly higher than those of the buccal and lingual side (P>0.05), in which:(45±8) μm in mesial, (50±10) μm in the distal, (33±8) μm in the buccal and (33±6) μm in the lingual side. The RMS value of CEREC Omnicam oral scanner scanning distal finish line was greater than that of 3Shape TRIOS oral scanner (P < 0.05). Without adjacent teeth, (1) the RMS values of the complete finish lines of CEREC Omnicam oral scanner and 3 Shape TRIOS oral scanner were significantly reduced (P < 0.05), including CEREC Omnicam oral scanner (34±3) μm and 3 Shape TRIOS oral scanner (26±4) μm; (2) the RMS values of the buccal and lingual finish lines of CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner showed no significant changes (P>0.05), among which, CEREC Omnicam oral scanner buccal (44±7) μm, lingual (43±3) μm, 3Shape TRIOS oral scanner buccal (29±5) μm, lingual (40±7) μm. The RMS values of CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner were significantly reduced and there was no significant difference between them (P>0.05). CEREC Omnicam oral scanner (32±8) μm and 3Shape TRIOS oral scanner (32±6) μm. The RMS values of the distal finish lines of CEREC Omnicam oral scanner and 3 Shape TRIOS oral scanner also decreased significantly (P < 0.05), and CEREC Omnicam oral scanner (38±3) μm decreased more significantly, similar to 3Shape TRIOS oral scanner (36±1) μm, P>0.05. CONCLUSION When adjacent teeth exist in the full crown preparation, the mesial and distal parts of the finish line will be blocked by adjacent teeth, which will affect the trueness of the local finish line, and ultimately reduce the trueness of the complete finish line.
Computer-Aided Design ; Dental Care ; Dental Impression Technique ; Humans ; Imaging, Three-Dimensional ; Models, Dental ; Software ; Tooth