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Sample records for 3-dimensional printing modeling

  1. Mandibular reconstruction using stereolithographic 3-dimensional printing modeling technology.

    PubMed

    Cohen, Adir; Laviv, Amir; Berman, Phillip; Nashef, Rizan; Abu-Tair, Jawad

    2009-11-01

    Mandibular reconstruction can be challenging for the surgeon wishing to restore its unique geometry. Reconstruction can be achieved with titanium bone plates followed by autogenous bone grafting. Incorporation of the bone graft into the mandible provides continuity and strength required for proper esthetics and function and permitting dental implant rehabilitation at a later stage. Precious time in the operating room is invested in plate contouring to reconstruct the mandible. Rapid prototyping technologies can construct physical models from computer-aided design via 3-dimensional (3D) printers. A prefabricated 3D model is achieved, which assists in accurate contouring of plates and/or planning of bone graft harvest geometry before surgery. The 2 most commonly used rapid prototyping technologies are stereolithography and 3D printing (3DP). Three-dimensional printing is advantageous to stereolithography for better accuracy, quicker printing time, and lower cost. We present 3 clinical cases based on 3DP modeling technology. Models were fabricated before the resection of mandibular ameloblastoma and were used to prepare bridging plates before the first stage of reconstruction. In 1 case, another model was fabricated and used as a template for iliac crest bone graft in the second stage of reconstruction. The 3DP technology provided a precise, fast, and cheap mandibular reconstruction, which aids in shortened operation time (and therefore decreased exposure time to general anesthesia, decreased blood loss, and shorter wound exposure time) and easier surgical procedure.

  2. Use of 3-Dimensional Printing to Create Patient-Specific Thoracic Spine Models as Task Trainers.

    PubMed

    Jeganathan, Jelliffe; Baribeau, Yanick; Bortman, Jeffrey; Mahmood, Feroze; Shnider, Marc; Ahmed, Muneeb; Mashari, Azad; Amir, Rabia; Amador, Yannis; Matyal, Robina

    Thoracic epidural anesthesia is a technically challenging procedure with a high failure rate of 24% to 32% nationwide. Residents in anesthesiology have limited opportunities to practice this technique adequately, and there are no training tools available for this purpose. Our objective was to build a low-cost patient-specific thoracic epidural training model. We obtained thoracic computed tomography scan data from patients with normal and kyphotic spine. The thoracic spine was segmented from the scan, and a 3-dimensional model of the spine was generated and printed. It was then placed in a customized wooden box and filled with different types of silicone to mimic human tissues. Attending physicians in our institution then tested the final model. They were asked to fill out a brief questionnaire after the identification of the landmarks and epidural space using ultrasound and real-time performance for a thoracic epidural on the model (Supplemental Digital Content 1, http://links.lww.com/AAP/A197). Likert scoring system was used for scoring. The time to develop this simulator model took less than 4 days, and the materials cost approximately $400. Fourteen physicians tested the model for determining the realistic sensation while palpating the spinous process, needle entry through the silicone, the "pop" sensation and ultrasound fidelity of the model. Whereas the tactile fidelity scores were "neutral" (3.08, 3.06, and 3.0, respectively), the ultrasound guidance and overall suitability for residents were highly rated as being the most realistic (4.85 and 4.0, respectively). It is possible to develop homemade, low-cost, patient-specific, and high-fidelity ultrasound guidance simulators for resident training in thoracic epidurals using 3-dimensional printing technology.

  3. Using 3-dimensional printing to create presurgical models for endodontic surgery.

    PubMed

    Bahcall, James K

    2014-09-01

    Advances in endodontic surgery--from both a technological and procedural perspective-have been significant over the last 18 years. Although these technologies and procedural enhancements have significantly improved endodontic surgical treatment outcomes, there is still an ongoing challenge of overcoming the limitations of interpreting preoperative 2-dimensional (2-D) radiographic representation of a 3-dimensional (3-D) in vivo surgical field. Cone-beam Computed Tomography (CBCT) has helped to address this issue by providing a 3-D enhancement of the 2-D radiograph. The next logical step to further improve a presurgical case 3-D assessment is to create a surgical model from the CBCT scan. The purpose of this article is to introduce 3-D printing of CBCT scans for creating presurgical models for endodontic surgery.

  4. Benefits and Limitations of Entry-Level 3-Dimensional Printing of Maxillofacial Skeletal Models.

    PubMed

    Legocki, Alex T; Duffy-Peter, Andrew; Scott, Andrew R

    2017-04-01

    A protocol for creating exceptionally low-cost 3-dimensional (3-D) maxillofacial skeletal models does not require proficiency with computer software or intensive labor. Small and less affluent centers can produce models with little loss in accuracy and clinical utility. To highlight the feasibility and methods of introducing in-house, entry-level additive manufacturing (3-D printing) technology to otolaryngologic craniofacial reconstruction and to describe its clinical applications and limitations, including a comparison with available vendor models. This case series of 6 models (3 pairs) compared cost, side-by-side anatomical model fidelity, and clinical versatility using entry-level, in-house 3-D pediatric mandible model production vs high-end, third-party vendor modeling, including a review of the literature. Comparisons were made at an urban pediatric otolaryngology practice among patients who had previously undergone pediatric craniofacial reconstruction with use of a commercially produced medical model for surgical planning. Each vendor model had been produced using computed tomographic imaging data. With the use of this same data source, in-house models were printed in polylactic acid using a commercially available printer. Data were collected from November 1 to December 30, 2015. Models created from these 2 methods of production were assessed for fidelity of surface anatomy, resilience to manipulation and plate bending, cost of production, speed of production, sterilizability, virtual surgical planning options, and alveolar nerve canal and tooth root visibility in mandibles. For the quantitative comparisons between in-house models (1 neonatal, 1 pediatric, and 1 adult model) and their commercial counterparts, the mean value of 7 independent measurements was analyzed from each of 3 model pairs. Caliper measurements from models produced through entry-level, in-house manufacturing were comparable to those taken from commercially produced counterparts

  5. Evaluation of Nitinol Stents Using a 3-Dimensional Printed Superficial Femoral Artery Model: A Preliminary Study.

    PubMed

    Girsowicz, Elie; Georg, Yannick; Seiller, Hélène; Lejay, Anne; Thaveau, Fabien; Heim, Frédéric; Chakfe, Nabil

    2016-05-01

    Mechanical tests assessing Nitinol stents used for the superficial femoral artery (SFA) are designed without taking into account their deployment environments. The objectives of this study were (1) to create normal and pathologic femoral artery models, (2) to run mechanical tests reproducing the stresses of the SFA, and (3) to study and compare Nitinol stents in those conditions. Femoral artery models with identical mechanical properties to the SFA were created using the 3-dimensional printing technology. Those models were designed with and without an asymmetric focal 50% stenosis. Three mechanical tests (bending-compression, bending-compression-torsion, and multiple bending tests) were created and 1 flexible stent was tested, of 6 and 7-mm diameter. Three samples of the stent, LifeStent (Bard(®)), were deployed and tested in the models. Stents alone were evaluated in the same conditions. The analysis focused on the comparison of rheologic curves, level of kink, and the energy deployed for each stent to kink. In the 3 tests, all stents deployed in the models presented a kink during their evaluation. When tested alone, during the compression-bending and bending-compression-torsion tests, no plicature was observed. During the multiple bending test, the energy deployed to plicature for the stent tested alone was of 1.4 ± 0.10 and 2.84 ± 0.1 J compared with 9.7 ± 0.6 and 8.25 ± 0.6 J when deployed in the model for the Lifestent 6 × 80 and 7 × 80 mm, respectively. For all of these 3 tests, 6-mm diameter stents exhibited a level of kink and energy of kink higher than 7 mm stents. The behavior of the stents changed in the stenosed model whatever diameter is taken into account. Analysis of the rheologic curves showed a decrease in the inflection of the curve related to the plication. In the bending-compression test, the presence of a stenosis lead to an early plication of the model, with less deployed kinking energy whereas in the bending

  6. Cardiothoracic Applications of 3-dimensional Printing.

    PubMed

    Giannopoulos, Andreas A; Steigner, Michael L; George, Elizabeth; Barile, Maria; Hunsaker, Andetta R; Rybicki, Frank J; Mitsouras, Dimitris

    2016-09-01

    Medical 3-dimensional (3D) printing is emerging as a clinically relevant imaging tool in directing preoperative and intraoperative planning in many surgical specialties and will therefore likely lead to interdisciplinary collaboration between engineers, radiologists, and surgeons. Data from standard imaging modalities such as computed tomography, magnetic resonance imaging, echocardiography, and rotational angiography can be used to fabricate life-sized models of human anatomy and pathology, as well as patient-specific implants and surgical guides. Cardiovascular 3D-printed models can improve diagnosis and allow for advanced preoperative planning. The majority of applications reported involve congenital heart diseases and valvular and great vessels pathologies. Printed models are suitable for planning both surgical and minimally invasive procedures. Added value has been reported toward improving outcomes, minimizing perioperative risk, and developing new procedures such as transcatheter mitral valve replacements. Similarly, thoracic surgeons are using 3D printing to assess invasion of vital structures by tumors and to assist in diagnosis and treatment of upper and lower airway diseases. Anatomic models enable surgeons to assimilate information more quickly than image review, choose the optimal surgical approach, and achieve surgery in a shorter time. Patient-specific 3D-printed implants are beginning to appear and may have significant impact on cosmetic and life-saving procedures in the future. In summary, cardiothoracic 3D printing is rapidly evolving and may be a potential game-changer for surgeons. The imager who is equipped with the tools to apply this new imaging science to cardiothoracic care is thus ideally positioned to innovate in this new emerging imaging modality.

  7. Scan, plan, print, practice, perform: Development and use of a patient-specific 3-dimensional printed model in adult cardiac surgery.

    PubMed

    Hermsen, Joshua L; Burke, Thomas M; Seslar, Stephen P; Owens, David S; Ripley, Beth A; Mokadam, Nahush A; Verrier, Edward D

    2017-01-01

    Static 3-dimensional printing is used for operative planning in cases that involve difficult anatomy. An interactive 3D print allowing deliberate surgical practice would represent an advance. Two patients with hypertrophic cardiomyopathy had 3-dimensional prints constructed preoperatively. Stereolithography files were generated by segmentation of chest computed tomographic scans. Prints were made with hydrogel material, yielding tissue-like models that can be surgically manipulated. Septal myectomy of the print was performed preoperatively in the simulation laboratory. Volumetric measures of print and patient resected specimens were compared. An assessment tool was developed and used to rate the utility of this process. Clinical and echocardiographic data were reviewed. There was congruence between volumes of print and patient resection specimens (patient 1, 3.5 cm(3) and 3.0 cm(3), respectively; patient 2, 4.0 cm(3) and 4.0 cm(3), respectively). The prints were rated useful (3.5 and 3.6 on a 5-point Likert scale) for preoperative visualization, planning, and practice. Intraoperative echocardiographic assessment showed adequate relief of left ventricular outflow tract obstruction (patient 1, 80 mm Hg to 18 mm Hg; patient 2, 96 mm Hg to 9 mm Hg). Both patients reported symptomatic improvement (New York Heart Association functional class III to class I). Three-dimensional printing of interactive hypertrophic cardiomyopathy heart models allows for patient-specific preoperative simulation. Resection volume relationships were congruous on both specimens and suggest evidence of construct validity. This model also holds educational promise for simulation of a low-volume, high-risk operation that is traditionally difficult to teach. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  8. Estimation of Nasal Tip Support Using Computer-Aided Design and 3-Dimensional Printed Models

    PubMed Central

    Gray, Eric; Maducdoc, Marlon; Manuel, Cyrus; Wong, Brian J. F.

    2016-01-01

    IMPORTANCE Palpation of the nasal tip is an essential component of the preoperative rhinoplasty examination. Measuring tip support is challenging, and the forces that correspond to ideal tip support are unknown. OBJECTIVE To identify the integrated reaction force and the minimum and ideal mechanical properties associated with nasal tip support. DESIGN, SETTING, AND PARTICIPANTS Three-dimensional (3-D) printed anatomic silicone nasal models were created using a computed tomographic scan and computer-aided design software. From this model, 3-D printing and casting methods were used to create 5 anatomically correct nasal models of varying constitutive Young moduli (0.042, 0.086, 0.098, 0.252, and 0.302 MPa) from silicone. Thirty rhinoplasty surgeons who attended a regional rhinoplasty course evaluated the reaction force (nasal tip recoil) of each model by palpation and selected the model that satisfied their requirements for minimum and ideal tip support. Data were collected from May 3 to 4, 2014. RESULTS Of the 30 respondents, 4 surgeons had been in practice for 1 to 5 years; 9 surgeons, 6 to 15 years; 7 surgeons, 16 to 25 years; and 10 surgeons, 26 or more years. Seventeen surgeons considered themselves in the advanced to expert skill competency levels. Logistic regression estimated the minimum threshold for the Young moduli for adequate and ideal tip support to be 0.096 and 0.154 MPa, respectively. Logistic regression estimated the thresholds for the reaction force associated with the absolute minimum and ideal requirements for good tip recoil to be 0.26 to 4.74 N and 0.37 to 7.19 N during 1- to 8-mm displacement, respectively. CONCLUSIONS AND RELEVANCE This study presents a method to estimate clinically relevant nasal tip reaction forces, which serve as a proxy for nasal tip support. This information will become increasingly important in computational modeling of nasal tip mechanics and ultimately will enhance surgical planning for rhinoplasty. LEVEL OF EVIDENCE

  9. Mandibular reconstruction using plates prebent to fit rapid prototyping 3-dimensional printing models ameliorates contour deformity.

    PubMed

    Azuma, Masaki; Yanagawa, Toru; Ishibashi-Kanno, Naomi; Uchida, Fumihiko; Ito, Takaaki; Yamagata, Kenji; Hasegawa, Shogo; Sasaki, Kaoru; Adachi, Koji; Tabuchi, Katsuhiko; Sekido, Mitsuru; Bukawa, Hiroki

    2014-10-23

    Recently, medical rapid prototyping (MRP) models, fabricated with computer-aided design and computer-aided manufacture (CAD/CAM) techniques, have been applied to reconstructive surgery in the treatment of head and neck cancers. Here, we tested the use of preoperatively manufactured reconstruction plates, which were produced using MRP models. The clinical efficacy and esthetic outcome of using these products in mandibular reconstruction was evaluated. A series of 28 patients with malignant oral tumors underwent unilateral segmental resection of the mandible and simultaneous mandibular reconstruction. Twelve patients were treated with prebent reconstruction plates that were molded to MRP mandibular models designed with CAD/CAM techniques and fabricated on a combined powder bed and inkjet head three-dimensional printer. The remaining 16 patients were treated using conventional reconstruction methods. The surgical and esthetic outcomes of the two groups were compared by imaging analysis using post-operative panoramic tomography. The mandibular symmetry in patients receiving the MRP-model-based prebent plates was significantly better than that in patients receiving conventional reconstructive surgery. Patients with head and neck cancer undergoing reconstructive surgery using a prebent reconstruction plate fabricated according to an MRP mandibular model showed improved mandibular contour compared to patients undergoing conventional mandibular reconstruction. Thus, use of this new technology for mandibular reconstruction results in an improved esthetic outcome with the potential for improved quality of life for patients.

  10. Use of 3-dimensional printing technology and silicone modeling in surgical simulation: development and face validation in pediatric laparoscopic pyeloplasty.

    PubMed

    Cheung, Carling L; Looi, Thomas; Lendvay, Thomas S; Drake, James M; Farhat, Walid A

    2014-01-01

    Pediatric laparoscopy poses unique training challenges owing to smaller workspaces, finer sutures used, and potentially more delicate tissues that require increased surgical dexterity when compared with adult analogs. We describe the development and face validation of a pediatric pyeloplasty simulator using a low-cost laparoscopic dry-laboratory model developed with 3-dimensional (3D) printing and silicone modeling. The organs (the kidney, renal pelvis, and ureter) were created in a 3-step process where molds were created with 3D modeling software, printed with a Spectrum Z510 3D printer, and cast with Dragon Skin 30 silicone rubber. The model was secured in a laparoscopy box trainer. A pilot study was conducted at a Canadian Urological Association meeting. A total of 24 pediatric urology fellows and 3 experienced faculty members then assessed our skills module during a minimally invasive surgery training course. Participants had 60 minutes to perform a right-side pyeloplasty using laparoscopic tools and 5-0 VICRYL suture. Face validity was demonstrated on a 5-point Likert scale. The dry-laboratory model consists of a kidney, a replaceable dilated renal pelvis and ureter with an obstructed ureteropelvic junction, and an overlying peritoneum with an inscribed fundamentals of laparoscopic surgery pattern-cutting exercise. During initial validation at the Canadian Urological Association, participants rated (out of 5) 4.75 ± 0.29 for overall impression, 4.50 ± 0.41 for realism, and 4.38 ± 0.48 for handling. During the minimally invasive surgery course, 22 of 24 fellows and all the faculty members completed the scoring. Usability was rated 4 or 5 by 14 participants (overall, 3.6 ± 1.22 by novices and 3.7 ± 0.58 by experts), indicating that they would use the model in their own training and teaching. Esthetically, the model was rated 3.5 ± 0.74 (novices) and 3.3 ± 0.58 (experts). We developed a pediatric pyeloplasty simulator by applying a low-cost reusable model

  11. Accuracy of both virtual and printed 3-dimensional models for volumetric measurement of alveolar clefts before grafting with alveolar bone compared with a validated algorithm: a preliminary investigation.

    PubMed

    Kasaven, C P; McIntyre, G T; Mossey, P A

    2017-01-01

    Our objective was to assess the accuracy of virtual and printed 3-dimensional models derived from cone-beam computed tomographic (CT) scans to measure the volume of alveolar clefts before bone grafting. Fifteen subjects with unilateral cleft lip and palate had i-CAT cone-beam CT scans recorded at 0.2mm voxel and sectioned transversely into slices 0.2mm thick using i-CAT Vision. Volumes of alveolar clefts were calculated using first a validated algorithm; secondly, commercially-available virtual 3-dimensional model software; and finally 3-dimensional printed models, which were scanned with microCT and analysed using 3-dimensional software. For inter-observer reliability, a two-way mixed model intraclass correlation coefficient (ICC) was used to evaluate the reproducibility of identification of the cranial and caudal limits of the clefts among three observers. We used a Friedman test to assess the significance of differences among the methods, and probabilities of less than 0.05 were accepted as significant. Inter-observer reliability was almost perfect (ICC=0.987). There were no significant differences among the three methods. Virtual and printed 3-dimensional models were as precise as the validated computer algorithm in the calculation of volumes of the alveolar cleft before bone grafting, but virtual 3-dimensional models were the most accurate with the smallest 95% CI and, subject to further investigation, could be a useful adjunct in clinical practice. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Accuracy and mechanical properties of orthodontic models printed 3-dimensionally from calcium sulfate before and after various postprinting treatments.

    PubMed

    Ledingham, Austin D; English, Jeryl D; Akyalcin, Sercan; Cozad, Benjamin E; Ontiveros, Joe C; Kasper, F Kurtis

    2016-12-01

    Dental models fabricated with 3-dimensional printing technologies are revolutionizing the practice of orthodontics, but they generally comprise polymeric materials that may not be suitable for certain applications, such as soldering appliances. The objective of this study was to investigate the dimensional accuracy and mechanical properties of 3-dimensional printed ceramic-based models before and after various treatments intended to improve their mechanical properties. Thirty identical models were printed 3-dimensionally from a calcium sulfate-based substrate and divided into 3 groups for treatment: high heat (250°C for 30 minutes), low heat (150°C for 30 minutes), and Epsom salt treatment. Each model was scanned before and after treatment with a laser scanner, and dimensional stability was analyzed by digital superimpositions using a best-fit algorithm. The models were weighed before and after treatment to evaluate mass changes. Additionally, 3-dimensional printed cylinders treated as described above and an untreated control group were subjected to compressive mechanical testing (n = 11 per group). The Epsom salt treatment group had statistically significant increases in both peak compressive stress and modulus of elasticity when compared with the other treatment groups. All treatment groups had statistically significant changes in mass, with the Epsom salt group gaining mass and the 2 heat-treatment groups losing mass. The low-temperature treatment group had a statistically significantly lower mean average for dimensional deviations (0.026 ± 0.010 mm) than did the other treatment groups (0.069 ± 0.006 and 0.059 ± 0.010 mm for high temperature and Epsom salt, respectively). Dental models printed 3-dimensionally with calcium sulfate and treated with Epsom salt showed significant improvement in compressive mechanical properties and retained clinically acceptable dimensional stability. Copyright © 2016 American Association of Orthodontists

  13. Review of 3-Dimensional Printing on Cranial Neurosurgery Simulation Training.

    PubMed

    Vakharia, Vejay N; Vakharia, Nilesh N; Hill, Ciaran S

    2016-04-01

    Shorter working times, reduced operative exposure to complex procedures, and increased subspecialization have resulted in training constraints within most surgical fields. Simulation has been suggested as a possible means of acquiring new surgical skills without exposing patients to the surgeon's operative "learning curve." Here we review the potential impact of 3-dimensional printing on simulation and training within cranial neurosurgery and its implications for the future. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a comprehensive search of PubMed, OVID MEDLINE, Embase, and the Cochrane Database of Systematic Reviews was performed. In total, 31 studies relating to the use of 3-dimensional (3D) printing within neurosurgery, of which 16 were specifically related to simulation and training, were identified. The main impact of 3D printing on neurosurgical simulation training was within vascular surgery, where patient-specific replication of vascular anatomy and pathologies can aid surgeons in operative planning and clip placement for reconstruction of vascular anatomy. Models containing replicas of brain tumors have also been reconstructed and used for training purposes, with some providing realistic representations of skin, subcutaneous tissue, bone, dura, normal brain, and tumor tissue. 3D printing provides a unique means of directly replicating patient-specific pathologies. It can identify anatomic variation and provide a medium in which training models can be generated rapidly, allowing the trainee and experienced neurosurgeon to practice parts of operations preoperatively. Future studies are required to validate this technology in comparison with current simulators and show improved patient outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Projection printing of 3-dimensional tissue scaffolds.

    PubMed

    Lu, Yi; Chen, Shaochen

    2012-01-01

    Our ability to create precise, predesigned, spatially patterned biochemical and physical microenvironments inside polymer scaffolds could provide a powerful tool in studying progenitor cell behavior and differentiation under biomimetic, three-dimensional (3D) culture conditions. The development of freeform fabrication technology has become a promising tool for the manufacturing of biological scaffolds for tissue regeneration and stem cell engineering. Freeform fabrication is a very promising technology due to the efficient and simple process for creating bona fide 3D microstructures, such as closed channels and cavities. It is also capable of encapsulating biomolecules and even living cells. This chapter describes direct projection printing of 3D tissue engineering scaffolds by using a digital micromirror-array device (DMD) in a layer-by-layer process. This simple and fast microstereolithography system consists of an ultraviolet (UV) light source, a digital micromirror masking device, imaging optics, and controlling devices. Images of UV light are projected onto the photocurable resin by creating the "dynamic photomask" design with graphic software. Multilayered scaffolds are microfabricated through a photopolymerization process.

  15. Comparison of reconstructed rapid prototyping models produced by 3-dimensional printing and conventional stone models with different degrees of crowding.

    PubMed

    Wan Hassan, Wan Nurazreena; Yusoff, Yusnilawati; Mardi, Noor Azizi

    2017-01-01

    Rapid prototyping models can be reconstructed from stereolithographic digital study model data to produce hard-copy casts. In this study, we aimed to compare agreement and accuracy of measurements made with rapid prototyping and stone models for different degrees of crowding. The Z Printer 450 (3D Systems, Rock Hill, SC) reprinted 10 sets of models for each category of crowding (mild, moderate, and severe) scanned using a structured-light scanner (Maestro 3D, AGE Solutions, Pisa, Italy). Stone and RP models were measured using digital calipers for tooth sizes in the mesiodistal, buccolingual, and crown height planes and for arch dimension measurements. Bland-Altman and paired t test analyses were used to assess agreement and accuracy. Clinical significance was set at ±0.50 mm. Bland-Altman analysis showed the mean bias of measurements between the models to be within ±0.15 mm (SD, ±0.40 mm), but the 95% limits of agreement exceeded the cutoff point of ±0.50 mm (lower range, -0.81 to -0.41 mm; upper range, 0.34 to 0.76 mm). Paired t tests showed statistically significant differences for all planes in all categories of crowding except for crown height in the moderate crowding group and arch dimensions in the mild and moderate crowding groups. The rapid prototyping models were not clinically comparable with conventional stone models regardless of the degree of crowding. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  16. Application of 3-dimensional printing in hand surgery for production of a novel bone reduction clamp.

    PubMed

    Fuller, Sam M; Butz, Daniel R; Vevang, Curt B; Makhlouf, Mansour V

    2014-09-01

    Three-dimensional printing is being rapidly incorporated in the medical field to produce external prosthetics for improved cosmesis and fabricated molds to aid in presurgical planning. Biomedically engineered products from 3-dimensional printers are also utilized as implantable devices for knee arthroplasty, airway orthoses, and other surgical procedures. Although at first expensive and conceptually difficult to construct, 3-dimensional printing is now becoming more affordable and widely accessible. In hand surgery, like many other specialties, new or customized instruments would be desirable; however, the overall production cost restricts their development. We are presenting our step-by-step experience in creating a bone reduction clamp for finger fractures using 3-dimensional printing technology. Using free, downloadable software, a 3-dimensional model of a bone reduction clamp for hand fractures was created based on the senior author's (M.V.M.) specific design, previous experience, and preferences for fracture fixation. Once deemed satisfactory, the computer files were sent to a 3-dimensional printing company for the production of the prototypes. Multiple plastic prototypes were made and adjusted, affording a fast, low-cost working model of the proposed clamp. Once a workable design was obtained, a printing company produced the surgical clamp prototype directly from the 3-dimensional model represented in the computer files. This prototype was used in the operating room, meeting the expectations of the surgeon. Three-dimensional printing is affordable and offers the benefits of reducing production time and nurturing innovations in hand surgery. This article presents a step-by-step description of our design process using online software programs and 3-dimensional printing services. As medical technology advances, it is important that hand surgeons remain aware of available resources, are knowledgeable about how the process works, and are able to take advantage of

  17. Advances in 3-Dimensional Printing in Otolaryngology: A Review.

    PubMed

    VanKoevering, Kyle K; Hollister, Scott J; Green, Glenn E

    2017-02-01

    Three-dimensional (3-D) printing is an exponentially growing technology that enables the use of a patient's image data to create patient-specific models, devices, and implants. Three-dimensional printing, developed in the 1980s, has emerged in the past decade with the potential to create new paradigms in personalized medicine. The field of otolaryngology has advanced many current and evolving future medical applications of 3-D printing. The predominant uses of 3-D printing have rapidly progressed from patient-specific models and simulators to intraoperative guides. Continued advancements now include 3-D-printed implants and future tissue-engineered constructs, which bring new regulatory challenges. This review summarizes the literature and provides a comprehensive guide to the background, applications, and current limitations of 3-D printing across the head and neck. Three-dimensional printing enables the rapid production of patient-specific devices for personalized medicine. The field of otolaryngology has pioneered many of the underlying advancements in medical 3-D printing and will continue to remain at the forefront of 3-D printing technology.

  18. A 3-Dimensional Printed Ultrasound Probe Visuospatial Trainer.

    PubMed

    McKenna, Ryan T; Dove, Jesse C; Ratzlaff, Robert A; Diaz-Gomez, Jose L; Cox, Daniel J; Simon, Leslie V

    2017-09-04

    Training adult learners to use ultrasound in clinical practice relies on the ability of the learner to apply visuospatial concepts to the anatomy of the human body. We describe a visuospatial trainer that replicates the housing of an ultrasound transducer, through which a linear laser projects light in the same plane and orientation as the ultrasonic sound waves. We use this trainer in combination with a porcine heart dissection laboratory to teach bedside cardiac ultrasound and transthoracic echocardiography (TTE). Off-the-shelf components, including an on/off switch, a laser, and 2 ampere batteries are connected in series and placed inside the 3-dimensional (3D)-printed housing. The trainer's laser emission projects a red line that visually represents the ultrasound's field. Learners project the laser against a porcine or human heart in the orientation of the TTE window they wish to obtain and then dissect the heart in that plane, allowing for visualization of how grayscale images are obtained from 3D structures. Previous research has demonstrated that visuospatial aptitude is correlated with ultrasound procedural performance. We present this trainer and educational method as a specific training intervention that could enhance the visuospatial ability of the ultrasound learner. This visuospatial trainer and educational method present a novel process for enhancing learner understanding of 2-dimensional ultrasound images as they relate to 3D structures. Having a clear understanding of how images are generated in cross section may translate into more proficient adaptation of cardiac ultrasound and TTE.

  19. Systematic Review of the Use of 3-Dimensional Printing in Surgical Teaching and Assessment.

    PubMed

    Langridge, Benjamin; Momin, Sheikh; Coumbe, Ben; Woin, Evelina; Griffin, Michelle; Butler, Peter

    2017-07-17

    The use of 3-dimensional (3D) printing in medicine has rapidly expanded in recent years as the technology has developed. The potential uses of 3D printing are manifold. This article provides a systematic review of the uses of 3D printing within surgical training and assessment. A structured literature search of the major literature databases was performed in adherence to PRISMA guidelines. Articles that met predefined inclusion and exclusion criteria were appraised with respect to the key objectives of the review and sources of bias were analysed. Overall, 49 studies were identified for inclusion in the qualitative analysis. Heterogeneity in study design and outcome measures used prohibited meaningful meta-analysis. 3D printing has been used in surgical training across a broad range of specialities but most commonly in neurosurgery and otorhinolaryngology. Both objective and subjective outcome measures have been studied, demonstrating the usage of 3D printed models in training and education. 3D printing has also been used in anatomical education and preoperative planning, demonstrating improved outcomes when compared to traditional educational methods and improved patient outcomes, respectively. 3D printing technology has a broad range of potential applications within surgical education and training. Although the field is still in its relative infancy, several studies have already demonstrated its usage both instead of and in addition to traditional educational methods. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  20. 3-Dimensional Topographic Models for the Classroom

    NASA Technical Reports Server (NTRS)

    Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.

    2003-01-01

    We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.

  1. 3-Dimensional Topographic Models for the Classroom

    NASA Technical Reports Server (NTRS)

    Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.

    2003-01-01

    We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.

  2. Incorporating 3-dimensional models in online articles.

    PubMed

    Cevidanes, Lucia H S; Ruellas, Antonio C O; Jomier, Julien; Nguyen, Tung; Pieper, Steve; Budin, Francois; Styner, Martin; Paniagua, Beatriz

    2015-05-01

    The aims of this article are to introduce the capability to view and interact with 3-dimensional (3D) surface models in online publications, and to describe how to prepare surface models for such online 3D visualizations. Three-dimensional image analysis methods include image acquisition, construction of surface models, registration in a common coordinate system, visualization of overlays, and quantification of changes. Cone-beam computed tomography scans were acquired as volumetric images that can be visualized as 3D projected images or used to construct polygonal meshes or surfaces of specific anatomic structures of interest. The anatomic structures of interest in the scans can be labeled with color (3D volumetric label maps), and then the scans are registered in a common coordinate system using a target region as the reference. The registered 3D volumetric label maps can be saved in .obj, .ply, .stl, or .vtk file formats and used for overlays, quantification of differences in each of the 3 planes of space, or color-coded graphic displays of 3D surface distances. All registered 3D surface models in this study were saved in .vtk file format and loaded in the Elsevier 3D viewer. In this study, we describe possible ways to visualize the surface models constructed from cone-beam computed tomography images using 2D and 3D figures. The 3D surface models are available in the article's online version for viewing and downloading using the reader's software of choice. These 3D graphic displays are represented in the print version as 2D snapshots. Overlays and color-coded distance maps can be displayed using the reader's software of choice, allowing graphic assessment of the location and direction of changes or morphologic differences relative to the structure of reference. The interpretation of 3D overlays and quantitative color-coded maps requires basic knowledge of 3D image analysis. When submitting manuscripts, authors can now upload 3D models that will allow readers to

  3. Incorporating 3-dimensional models in online articles

    PubMed Central

    Cevidanes, Lucia H. S.; Ruellasa, Antonio C. O.; Jomier, Julien; Nguyen, Tung; Pieper, Steve; Budin, Francois; Styner, Martin; Paniagua, Beatriz

    2015-01-01

    Introduction The aims of this article were to introduce the capability to view and interact with 3-dimensional (3D) surface models in online publications, and to describe how to prepare surface models for such online 3D visualizations. Methods Three-dimensional image analysis methods include image acquisition, construction of surface models, registration in a common coordinate system, visualization of overlays, and quantification of changes. Cone-beam computed tomography scans were acquired as volumetric images that can be visualized as 3D projected images or used to construct polygonal meshes or surfaces of specific anatomic structures of interest. The anatomic structures of interest in the scans can be labeled with color (3D volumetric label maps), and then the scans are registered in a common coordinate system using a target region as the reference. The registered 3D volumetric label maps can be saved in .obj, .ply, .stl, or .vtk file formats and used for overlays, quantification of differences in each of the 3 planes of space, or color-coded graphic displays of 3D surface distances. Results All registered 3D surface models in this study were saved in .vtk file format and loaded in the Elsevier 3D viewer. In this study, we describe possible ways to visualize the surface models constructed from cone-beam computed tomography images using 2D and 3D figures. The 3D surface models are available in the article’s online version for viewing and downloading using the reader’s software of choice. These 3D graphic displays are represented in the print version as 2D snapshots. Overlays and color-coded distance maps can be displayed using the reader’s software of choice, allowing graphic assessment of the location and direction of changes or morphologic differences relative to the structure of reference. The interpretation of 3D overlays and quantitative color-coded maps requires basic knowledge of 3D image analysis. Conclusions When submitting manuscripts, authors can

  4. Monolithically integrated Helmholtz coils by 3-dimensional printing

    SciTech Connect

    Li, Longguang; Abedini-Nassab, Roozbeh; Yellen, Benjamin B.

    2014-06-23

    3D printing technology is of great interest for the monolithic fabrication of integrated systems; however, it is a challenge to introduce metallic components into 3D printed molds to enable broader device functionality. Here, we develop a technique for constructing a multi-axial Helmholtz coil by injecting a eutectic liquid metal Gallium Indium alloy (EGaIn) into helically shaped orthogonal cavities constructed in a 3D printed block. The tri-axial solenoids each carry up to 3.6 A of electrical current and produce magnetic field up to 70 G. Within the central section of the coil, the field variation is less than 1% and is in agreement with theory. The flow rates and critical pressures required to fill the 3D cavities with liquid metal also agree with theoretical predictions and provide scaling trends for filling the 3D printed parts. These monolithically integrated solenoids may find future applications in electronic cell culture platforms, atomic traps, and miniaturized chemical analysis systems based on nuclear magnetic resonance.

  5. Monolithically integrated Helmholtz coils by 3-dimensional printing

    NASA Astrophysics Data System (ADS)

    Li, Longguang; Abedini-Nassab, Roozbeh; Yellen, Benjamin B.

    2014-06-01

    3D printing technology is of great interest for the monolithic fabrication of integrated systems; however, it is a challenge to introduce metallic components into 3D printed molds to enable broader device functionality. Here, we develop a technique for constructing a multi-axial Helmholtz coil by injecting a eutectic liquid metal Gallium Indium alloy (EGaIn) into helically shaped orthogonal cavities constructed in a 3D printed block. The tri-axial solenoids each carry up to 3.6 A of electrical current and produce magnetic field up to 70 G. Within the central section of the coil, the field variation is less than 1% and is in agreement with theory. The flow rates and critical pressures required to fill the 3D cavities with liquid metal also agree with theoretical predictions and provide scaling trends for filling the 3D printed parts. These monolithically integrated solenoids may find future applications in electronic cell culture platforms, atomic traps, and miniaturized chemical analysis systems based on nuclear magnetic resonance.

  6. Clinical applications of 3-dimensional printing in radiation therapy.

    PubMed

    Zhao, Yizhou; Moran, Kathryn; Yewondwossen, Mammo; Allan, James; Clarke, Scott; Rajaraman, Murali; Wilke, Derek; Joseph, Paul; Robar, James L

    2017-01-01

    Three-dimensional (3D) printing is suitable for the fabrication of complex radiotherapy bolus. Although investigated from dosimetric and feasibility standpoints, there are few reports to date of its use for actual patient treatment. This study illustrates the versatile applications of 3D printing in clinical radiation oncology through a selection of patient cases, namely, to create bolus for photon and modulated electron radiotherapy (MERT), as well as applicators for surface high-dose rate (HDR) brachytherapy. Photon boluses were 3D-printed to treat a recurrent squamous cell carcinoma (SCC) of the nasal septum and a basal cell carcinoma (BCC) of the posterior pinna. For a patient with a mycosis fungoides involving the upper face, a 3D-printed MERT bolus was used. To treat an SCC of the nose, a 3D-printed applicator for surface brachytherapy was made. The structures' fit to the anatomy and the radiotherapy treatment plans were assessed. Based on the treatment planning computed tomography (CT), the size of the largest air gap at the interface of the 3D-printed structure was 3 mm for the SCC of the nasal septum, 3 mm for the BCC of the pinna, 2 mm for the mycosis fungoides of the face, and 2 mm for the SCC of the nose. Acceptable treatment plans were obtained for the SCC of the nasal septum (95% isodose to 99.8% of planning target volume [PTV]), the BCC of the pinna (95% isodose to 97.7% of PTV), and the mycosis fungoides of the face (90% isodose to 92.5% of PTV). For the latter, compared with a plan with a uniform thickness bolus, the one featuring the MERT bolus achieved relative sparing of all the organs at risk (OARs) distal to the target volume, while maintaining similar target volume coverage. The surface brachytherapy plan for the SCC of the nose had adequate coverage (95% isodose to 95.6% of clinical target volume [CTV]), but a relatively high dose to the left eye, owing to its proximity to the tumor. 3D printing can be implemented effectively in the

  7. Dental implant customization using numerical optimization design and 3-dimensional printing fabrication of zirconia ceramic.

    PubMed

    Cheng, Yung-Chang; Lin, Deng-Huei; Jiang, Cho-Pei; Lin, Yuan-Min

    2017-05-01

    This study proposes a new methodology for dental implant customization consisting of numerical geometric optimization and 3-dimensional printing fabrication of zirconia ceramic. In the numerical modeling, exogenous factors for implant shape include the thread pitch, thread depth, maximal diameter of implant neck, and body size. Endogenous factors are bone density, cortical bone thickness, and non-osseointegration. An integration procedure, including uniform design method, Kriging interpolation and genetic algorithm, is applied to optimize the geometry of dental implants. The threshold of minimal micromotion for optimization evaluation was 100 μm. The optimized model is imported to the 3-dimensional slurry printer to fabricate the zirconia green body (powder is bonded by polymer weakly) of the implant. The sintered implant is obtained using a 2-stage sintering process. Twelve models are constructed according to uniform design method and simulated the micromotion behavior using finite element modeling. The result of uniform design models yields a set of exogenous factors that can provide the minimal micromotion (30.61 μm), as a suitable model. Kriging interpolation and genetic algorithm modified the exogenous factor of the suitable model, resulting in 27.11 μm as an optimization model. Experimental results show that the 3-dimensional slurry printer successfully fabricated the green body of the optimization model, but the accuracy of sintered part still needs to be improved. In addition, the scanning electron microscopy morphology is a stabilized t-phase microstructure, and the average compressive strength of the sintered part is 632.1 MPa. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Application of 3-Dimensional Printing Technology to Kirschner Wire Fixation of Adolescent Condyle Fracture.

    PubMed

    Dong, Zhiwei; Li, Qihong; Bai, Shizhu; Zhang, Li

    2015-10-01

    Condyle fractures are common in children and are increasingly treated with open reduction. Three-dimensional printing has developed into an important method of assisting surgical treatment. This report describes the case of a 14-year-old patient treated for a right condyle fracture at the authors' hospital. Preoperatively, the authors designed a surgical guide using 3-dimensional printing and virtual surgery. The 3-dimensional surgical guide allowed accurate alignment of the fracture using Kirschner wire without additional dissection and tissue injury. Kirschner wire fixation augmented by 3-dimensional printing technology produced a good outcome in this adolescent condyle fracture. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Percutaneous Nephrolithotomy Using an Individual 3-Dimensionally Printed Surgical Guide.

    PubMed

    Golab, Adam; Smektala, Tomasz; Krolikowski, Marcin; Slojewski, Marcin

    2016-05-13

    Percutaneous nephrolithotomy (PNL) is an endoscopic technique used for treating large stones, multiple stones, and staghorn calculi. Although minimally invasive, complication rate of PNL reaches 25%, and it is partially associated with needle puncture during nephrostomy tract preparation. Continuous improvement of armamentarium and imaging methods and the introduction of three-dimensional (3D) visualizations optimize the procedure; however, the rapid and precise establishment of the nephrostomy tract is still difficult. In the present short communication, we present the PNL procedure assisted by a personalized 3D-printed surgical guide (SG) to ensure fast and precise needle access to the renal collecting system. We also describe the workflow for SG preparation, which consists of CT image acquisition and data segmentation, planning a safe needle insertion path, SG designing, and guide manufacturing. With the growing market of low-cost 3D printers, the presented technique can shorten the PNL procedure time and decrease the complication rate associated with needle puncture in a cost-efficient manner.

  10. A Novel Method of Orbital Floor Reconstruction Using Virtual Planning, 3-Dimensional Printing, and Autologous Bone.

    PubMed

    Vehmeijer, Maarten; van Eijnatten, Maureen; Liberton, Niels; Wolff, Jan

    2016-08-01

    Fractures of the orbital floor are often a result of traffic accidents or interpersonal violence. To date, numerous materials and methods have been used to reconstruct the orbital floor. However, simple and cost-effective 3-dimensional (3D) printing technologies for the treatment of orbital floor fractures are still sought. This study describes a simple, precise, cost-effective method of treating orbital fractures using 3D printing technologies in combination with autologous bone. Enophthalmos and diplopia developed in a 64-year-old female patient with an orbital floor fracture. A virtual 3D model of the fracture site was generated from computed tomography images of the patient. The fracture was virtually closed using spline interpolation. Furthermore, a virtual individualized mold of the defect site was created, which was manufactured using an inkjet printer. The tangible mold was subsequently used during surgery to sculpture an individualized autologous orbital floor implant. Virtual reconstruction of the orbital floor and the resulting mold enhanced the overall accuracy and efficiency of the surgical procedure. The sculptured autologous orbital floor implant showed an excellent fit in vivo. The combination of virtual planning and 3D printing offers an accurate and cost-effective treatment method for orbital floor fractures.

  11. Computer aided-designed, 3-dimensionally printed porous tissue bioscaffolds for craniofacial soft tissue reconstruction.

    PubMed

    Zopf, David A; Mitsak, Anna G; Flanagan, Colleen L; Wheeler, Matthew; Green, Glenn E; Hollister, Scott J

    2015-01-01

    To determine the potential of an integrated, image-based computer-aided design (CAD) and 3-dimensional (3D) printing approach to engineer scaffolds for head and neck cartilaginous reconstruction for auricular and nasal reconstruction. Proof of concept revealing novel methods for bioscaffold production with in vitro and in vivo animal data. Multidisciplinary effort encompassing 2 academic institutions. Digital Imaging and Communications in Medicine (DICOM) computed tomography scans were segmented and utilized in image-based CAD to create porous, anatomic structures. Bioresorbable polycaprolactone scaffolds with spherical and random porous architecture were produced using a laser-based 3D printing process. Subcutaneous in vivo implantation of auricular and nasal scaffolds was performed in a porcine model. Auricular scaffolds were seeded with chondrogenic growth factors in a hyaluronic acid/collagen hydrogel and cultured in vitro over 2 months' duration. Auricular and nasal constructs with several types of microporous architecture were rapidly manufactured with high fidelity to human patient anatomy. Subcutaneous in vivo implantation of auricular and nasal scaffolds resulted in an excellent appearance and complete soft tissue ingrowth. Histological analysis of in vitro scaffolds demonstrated native-appearing cartilaginous growth that respected the boundaries of the scaffold. Integrated, image-based CAD and 3D printing processes generated patient-specific nasal and auricular scaffolds that supported cartilage regeneration. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  12. Use of 3-Dimensional Printing for Preoperative Planning in the Treatment of Recurrent Anterior Shoulder Instability

    PubMed Central

    Sheth, Ujash; Theodoropoulos, John; Abouali, Jihad

    2015-01-01

    Recurrent anterior shoulder instability often results from large bony Bankart or Hill-Sachs lesions. Preoperative imaging is essential in guiding our surgical management of patients with these conditions. However, we are often limited to making an attempt to interpret a 3-dimensional (3D) structure using conventional 2-dimensional imaging. In cases in which complex anatomy or bony defects are encountered, this type of imaging is often inadequate. We used 3D printing to produce a solid 3D model of a glenohumeral joint from a young patient with recurrent anterior shoulder instability and complex Bankart and Hill-Sachs lesions. The 3D model from our patient was used in the preoperative planning stages of an arthroscopic Bankart repair and remplissage to determine the depth of the Hill-Sachs lesion and the degree of abduction and external rotation at which the Hill-Sachs lesion engaged. PMID:26759768

  13. Biomechanical Properties of 3-Dimensional Printed Volar Locking Distal Radius Plate: Comparison With Conventional Volar Locking Plate.

    PubMed

    Kim, Sung-Jae; Jo, Young-Hoon; Choi, Wan-Sun; Lee, Chang-Hun; Lee, Bong-Gun; Kim, Joo-Hak; Lee, Kwang-Hyun

    2017-09-01

    This study evaluated the biomechanical properties of a new volar locking plate made by 3-dimensional printing using titanium alloy powder and 2 conventional volar locking plates under static and dynamic loading conditions that were designed to replicate those seen during fracture healing and early postoperative rehabilitation. For all plate designs, 12 fourth-generation synthetic composite radii were fitted with volar locking plates according to the manufacturers' technique after segmental osteotomy. Each specimen was first preloaded 10 N and then was loaded to 100 N, 200 N, and 300 N in phases at a rate of 2 N/s. Each construct was then dynamically loaded for 2,000 cycles of fatigue loading in each phase for a total 10,000 cycles. Finally, the constructs were loaded to a failure at a rate of 5 mm/min. All 3 plates showed increasing stiffness at higher loads. The 3-dimensional printed volar locking plate showed significantly higher stiffness at all dynamic loading tests compared with the 2 conventional volar locking plates. The 3-dimensional printed volar locking plate had the highest yield strength, which was significantly higher than those of 2 conventional volar locking plates. A 3-dimensional printed volar locking plate has similar stiffness to conventional plates in an experimental model of a severely comminuted distal radius fracture in which the anterior and posterior metaphyseal cortex are involved. These results support the potential clinical utility of 3-dimensional printed volar locking plates in which design can be modified according the fracture configuration and the anatomy of the radius. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  14. Construction of 3-Dimensional Printed Ultrasound Phantoms With Wall-less Vessels.

    PubMed

    Nikitichev, Daniil I; Barburas, Anamaria; McPherson, Kirstie; Mari, Jean-Martial; West, Simeon J; Desjardins, Adrien E

    2016-06-01

    Ultrasound phantoms are invaluable as training tools for vascular access procedures. We developed ultrasound phantoms with wall-less vessels using 3-dimensional printed chambers. Agar was used as a soft tissue-mimicking material, and the wall-less vessels were created with rods that were retracted after the agar was set. The chambers had integrated luer connectors to allow for fluid injections with clinical syringes. Several variations on this design are presented, which include branched and stenotic vessels. The results show that 3-dimensional printing can be well suited to the construction of wall-less ultrasound phantoms, with designs that can be readily customized and shared electronically. © 2016 by the American Institute of Ultrasound in Medicine.

  15. Application of a 3-dimensional printed navigation template in Bernese periacetabular osteotomies

    PubMed Central

    Zhou, You; Kang, Xiaopeng; Li, Chuan; Xu, Xiaoshan; Li, Rong; Wang, Jun; Li, Wei; Luo, Haotian; Lu, Sheng

    2016-01-01

    Abstract The aim of the present study was to describe the application of 3D printed templates for intraoperative navigation and simulation of periacetabular osteotomies (PAOs) in a cadaveric model. Five cadaveric specimens (10 sides) underwent thin-slice computed tomographic scans of the ala of ilium downwards to the proximal end of femoral shaft. Bernese PAO was performed. Using Mimics v10.1 software (Materialise, Leuven, Belgium), 3D computed tomographic reconstructions were created and the 4 standard PAO bone cuts—ischial, pubic, anterior, and posterior aspects of the ilium—as well as rotation of the dislocated acetabular bone blocks were simulated for each specimen. Using these data, custom 3D printed bone-drilling templates of the pelvis were manufactured, to guide surgical placement of the PAO bone cuts. An angle fix wedge was designed and printed, to help accurately achieve the predetermined rotation angle of the acetabular bone block. Each specimen underwent a conventional PAO. Preoperative, postsimulation, and postoperative lateral center-edge angles, acetabular indices, extrusion indices, and femoral head coverage were measured and compared; P and t values were calculated for above-mentioned measurements while comparing preoperative and postoperative data, and also in postsimulation and postoperative data comparison. All 10 PAO osteotomies were successfully completed using the 3D printed bone-drilling template and angle fix wedge. No osteotomy entered the hip joint and a single posterior column fracture was observed. Comparison of preoperative and postoperative measurements of the 10 sides showed statistically significant changes, whereas no statistically significant differences between postsimulation and postoperative values were noted, demonstrating the accuracy and utility of the 3D printed templates. The application of patient-specific 3D printed bone-drilling and rotation templates in PAO is feasible and may facilitate improved clinical outcomes

  16. Application of a 3-dimensional printed navigation template in Bernese periacetabular osteotomies: A cadaveric study.

    PubMed

    Zhou, You; Kang, Xiaopeng; Li, Chuan; Xu, Xiaoshan; Li, Rong; Wang, Jun; Li, Wei; Luo, Haotian; Lu, Sheng

    2016-12-01

    The aim of the present study was to describe the application of 3D printed templates for intraoperative navigation and simulation of periacetabular osteotomies (PAOs) in a cadaveric model.Five cadaveric specimens (10 sides) underwent thin-slice computed tomographic scans of the ala of ilium downwards to the proximal end of femoral shaft. Bernese PAO was performed. Using Mimics v10.1 software (Materialise, Leuven, Belgium), 3D computed tomographic reconstructions were created and the 4 standard PAO bone cuts-ischial, pubic, anterior, and posterior aspects of the ilium-as well as rotation of the dislocated acetabular bone blocks were simulated for each specimen. Using these data, custom 3D printed bone-drilling templates of the pelvis were manufactured, to guide surgical placement of the PAO bone cuts. An angle fix wedge was designed and printed, to help accurately achieve the predetermined rotation angle of the acetabular bone block. Each specimen underwent a conventional PAO. Preoperative, postsimulation, and postoperative lateral center-edge angles, acetabular indices, extrusion indices, and femoral head coverage were measured and compared; P and t values were calculated for above-mentioned measurements while comparing preoperative and postoperative data, and also in postsimulation and postoperative data comparison.All 10 PAO osteotomies were successfully completed using the 3D printed bone-drilling template and angle fix wedge. No osteotomy entered the hip joint and a single posterior column fracture was observed. Comparison of preoperative and postoperative measurements of the 10 sides showed statistically significant changes, whereas no statistically significant differences between postsimulation and postoperative values were noted, demonstrating the accuracy and utility of the 3D printed templates.The application of patient-specific 3D printed bone-drilling and rotation templates in PAO is feasible and may facilitate improved clinical outcomes, through the use

  17. Advantages and disadvantages of 3-dimensional printing in surgery: A systematic review.

    PubMed

    Martelli, Nicolas; Serrano, Carole; van den Brink, Hélène; Pineau, Judith; Prognon, Patrice; Borget, Isabelle; El Batti, Salma

    2016-06-01

    Three-dimensional (3D) printing is becoming increasingly important in medicine and especially in surgery. The aim of the present work was to identify the advantages and disadvantages of 3D printing applied in surgery. We conducted a systematic review of articles on 3D printing applications in surgery published between 2005 and 2015 and identified using a PubMed and EMBASE search. Studies dealing with bioprinting, dentistry, and limb prosthesis or those not conducted in a hospital setting were excluded. A total of 158 studies met the inclusion criteria. Three-dimensional printing was used to produce anatomic models (n = 113, 71.5%), surgical guides and templates (n = 40, 25.3%), implants (n = 15, 9.5%) and molds (n = 10, 6.3%), and primarily in maxillofacial (n = 79, 50.0%) and orthopedic (n = 39, 24.7%) operations. The main advantages reported were the possibilities for preoperative planning (n = 77, 48.7%), the accuracy of the process used (n = 53, 33.5%), and the time saved in the operating room (n = 52, 32.9%); 34 studies (21.5%) stressed that the accuracy was not satisfactory. The time needed to prepare the object (n = 31, 19.6%) and the additional costs (n = 30, 19.0%) were also seen as important limitations for routine use of 3D printing. The additional cost and the time needed to produce devices by current 3D technology still limit its widespread use in hospitals. The development of guidelines to improve the reporting of experience with 3D printing in surgery is highly desirable. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Morphological analysis and preoperative simulation of a double-chambered right ventricle using 3-dimensional printing technology.

    PubMed

    Shirakawa, Takashi; Koyama, Yasushi; Mizoguchi, Hiroki; Yoshitatsu, Masao

    2016-05-01

    We present a case of a double-chambered right ventricle in adulthood, in which we tried a detailed morphological assessment and preoperative simulation using 3-dimensional (3D) heart models for improved surgical planning. Polygonal object data for the heart were constructed from computed tomography images of this patient, and transferred to a desktop 3D printer to print out models in actual size. Medical staff completed all of the work processes. Because the 3D heart models were examined by hand, observed from various viewpoints and measured by callipers with ease, we were able to create an image of the complete form of the heart. The anatomical structure of an anomalous bundle was clearly observed, and surgical approaches to the lesion were simulated accurately. During surgery, we used an incision on the pulmonary infundibulum and resected three muscular components of the stenosis. The similarity between the models and the actual heart was excellent. As a result, the operation for this rare defect was performed safely and successfully. We concluded that the custom-made model was useful for morphological analysis and preoperative simulation. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  19. Customized Polymethylmethacrylate Cranioplasty Implants Using 3-Dimensional Printed Polylactic Acid Molds: Technical Note with 2 Illustrative Cases.

    PubMed

    Abdel Hay, Joe; Smayra, Tarek; Moussa, Ronald

    2017-09-01

    Prefabricated customized cranioplasty implants are anatomically more accurate than manually shaped acrylic implants but remain costly. The authors describe a new cost-effective technique of producing customized polymethylmethacrylate (PMMA) cranioplasty implants with the use of prefabricated 3-dimensional (3D) printed molds. The first patient had a left frontal cranial defect after a craniotomy for a glial tumor. A 3D image of his skull was obtained from axial 0.6-mm computed tomography (CT) scan images. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of his cranium as a model. The second patient had a bifrontal defect after the resection of an infected customized polyetheretherketone implant. A 3D image of the infected implant was directly obtained from an axial 0.6-mm CT scan before discarding it. The images were then used to produce for each patient a mold of the external surface of the cranium using a low-cost polylactic acid 3D printer. Intraoperatively, each mold was put in a sterile bag and then used to cast a customized PMMA implant subsequently trimmed before fixation. Both patients had excellent cosmetic results and underwent postoperative CT scans that showed excellent restoration of the symmetrical contours of the cranium. No neurologic or infectious complications occurred over a 6-month follow-up for either patient. Making customized PMMA cranioplasty implants via 3D printed polylactic acid molds is a cost-effective technique for delayed reconstruction of various cranial defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. [3-Dimensional model reconstruction of penis and surrounding tissue].

    PubMed

    Wang, Rui-Heng; Cao, Chuan; Mei, Wen-Ming; Wang, Wen-Xian; Tan, Li-Wen; Li, Shi-Rong

    2012-07-01

    To evaluate the feasibility of 3-Dimensional (3-D) model reconstruction of penis and surrounding structures based on magnetic resonance images, which may provide the model building method for modeling surgery of individual penoplasty. Magnetic resonance (MR) images of penis with different imaging parameters were evaluated. With the surface rendering construction, the 3D virtual model was established by Amira software. The anatomical details imaging is better in T2-weighted fast spin-echo images with 3.0 mm slice thickness. The established model based on the MR images can show the soft-tissue, suspensory ligament of the penis. The suspensory ligament stretches between the pubic symphysis and the corpora cavernosa. The penile roots attach to inferior ramus of pubis. MR imaging provides enough anatomical information for modeling. It can be used for the development of model surgery system of individual penoplasty.

  1. Customized Knee Prosthesis in Treatment of Giant Cell Tumors of the Proximal Tibia: Application of 3-Dimensional Printing Technology in Surgical Design

    PubMed Central

    Luo, Wenbin; Huang, Lanfeng; Liu, He; Qu, Wenrui; Zhao, Xin; Wang, Chenyu; Li, Chen; Yu, Tao; Han, Qing; Wang, Jincheng; Qin, Yanguo

    2017-01-01

    Background We explored the application of 3-dimensional (3D) printing technology in treating giant cell tumors (GCT) of the proximal tibia. A tibia block was designed and produced through 3D printing technology. We expected that this 3D-printed block would fill the bone defect after en-bloc resection. Importantly, the block, combined with a standard knee joint prosthesis, provided attachments for collateral ligaments of the knee, which can maintain knee stability. Material/Methods A computed tomography (CT) scan was taken of both knee joints in 4 patients with GCT of the proximal tibia. We developed a novel technique – the real-size 3D-printed proximal tibia model – to design preoperative treatment plans. Hence, with the application of 3D printing technology, a customized proximal tibia block could be designed for each patient individually, which fixed the bone defect, combined with standard knee prosthesis. Results In all 4 cases, the 3D-printed block fitted the bone defect precisely. The motion range of the affected knee was 90 degrees on average, and the soft tissue balance and stability of the knee were good. After an average 7-month follow-up, the MSTS score was 19 on average. No sign of prosthesis fracture, loosening, or other relevant complications were detected. Conclusions This technique can be used to treat GCT of the proximal tibia when it is hard to achieve soft tissue balance after tumor resection. 3D printing technology simplified the design and manufacturing progress of custom-made orthopedic medical instruments. This new surgical technique could be much more widely applied because of 3D printing technology. PMID:28388595

  2. Fabrication of a 3 dimensional dielectrophoresis electrode by a metal inkjet printing method

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Yun, Gyu-Young; Koh, Yul; Lee, Sang-Ho; Kim, Yong-Kweon

    2013-12-01

    We proposed a micro electrode fabrication method by a metal inkjet printing technology for the bio-applications of dielectrophoresis (DEP). The electrodes are composed of bottom planar gold (Au) electrodes and three dimensional (3D) silver (Ag) electrodes fabricated locally on the Au electrode through metal inkjet printing. We observed the negative DEP characteristics of the 4 μm polystyrene beads on the both electrodes at the 500 kHz, AC 20 Vpp point. The number of beads trapped on the printed Ag electrode is 79 and 25 on the planar Au electrode because of spatially larger electric field in a 3D electrode system.

  3. End User Comparison of Anatomically Matched 3-Dimensional Printed and Virtual Haptic Temporal Bone Simulation: A Pilot Study.

    PubMed

    Hochman, Jordan Brent; Rhodes, Charlotte; Kraut, Jay; Pisa, Justyn; Unger, Bertram

    2015-08-01

    Simulation has assumed a prominent role in education. It is important to explore the effectiveness of different modalities. In this article, we directly compare surgical resident impression of 2 distinct temporal bone simulations (physical and haptic). Research Ethics Board-approved prospective cohort study. A haptic voxel-based virtual model (VM) and a physical 3-dimensional printed temporal bone model (PBM) were developed. Participants rated each construct on a number of parameters and performed a direct comparison of the simulations using a survey instrument that employed a 7-point Likert scale and rank lists. Ten otolaryngology residents dissected anatomically identical, matched physical and virtual models. Data for both simulations originated from 10 unique cadaveric micro-computed tomography images. Subjects rated the PBM drill quality as being more similar to cadaveric temporal bone than the VM (cortical bone mean: 5.5 vs 3.2, P = .011; trabecular bone mean: 5.2 vs 2.8, P = .004) and with better air cell system representation (mean: 5.4 vs 4.5, P = .003). Subjects strongly agreed that both simulations are effective educational tools, but they rated the PBM higher (mean: 6.7 vs 5.4, P = .019). Notably, subjects agreed that both modalities should be integrated into training, but they were more favorably inclined toward the PBM (mean: 7.0 vs 5.5, P = .002). In direct comparison, the PBM was the preferred simulation in 7 of 9 educational domains. Appraisal of a PBM and a VM found both to have perceived educational benefit. However, the PBM was considered to have more realistic physical properties and was considered the preferred training instrument. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  4. A Simple 3-Dimensional Printed Aid for a Corrective Palmar Opening Wedge Osteotomy of the Distal Radius.

    PubMed

    Honigmann, Philipp; Thieringer, Florian; Steiger, Regula; Haefeli, Mathias; Schumacher, Ralf; Henning, Julia

    2016-03-01

    The reconstruction of malunited distal radius fractures is often challenging. Virtual planning techniques and guides for drilling and resection have been used for several years to achieve anatomic reconstruction. These guides have the advantage of leading to better operative results and faster surgery. Here, we describe a technique using a simple implant independent 3-dimensional printed drill guide and template to simplify the surgical reconstruction of a malunited distal radius fracture. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  5. Manufacture and evaluation of 3-dimensional printed sizing tools for use during intraoperative breast brachytherapy.

    PubMed

    Walker, Joshua M; Elliott, David A; Kubicky, Charlotte D; Thomas, Charles R; Naik, Arpana M

    2016-01-01

    Three-dimensional (3D) printing has emerged as a promising modality for the production of medical devices. Here we describe the design, production, and implementation of a series of sizing tools for use in an intraoperative breast brachytherapy program. These devices were produced using a commercially available low-cost 3D printer and software, and their implementation resulted in an immediate decrease in consumable costs without affecting the quality of care or the speed of delivery. This work illustrates the potential of 3D printing to revolutionize the field of medical devices, enabling physicians to rapidly develop and prototype novel tools.

  6. Development and Validation of a 3-Dimensional CFB Furnace Model

    NASA Astrophysics Data System (ADS)

    Vepsäläinen, Arl; Myöhänen, Karl; Hyppäneni, Timo; Leino, Timo; Tourunen, Antti

    At Foster Wheeler, a three-dimensional CFB furnace model is essential part of knowledge development of CFB furnace process regarding solid mixing, combustion, emission formation and heat transfer. Results of laboratory and pilot scale phenomenon research are utilized in development of sub-models. Analyses of field-test results in industrial-scale CFB boilers including furnace profile measurements are simultaneously carried out with development of 3-dimensional process modeling, which provides a chain of knowledge that is utilized as feedback for phenomenon research. Knowledge gathered by model validation studies and up-to-date parameter databases are utilized in performance prediction and design development of CFB boiler furnaces. This paper reports recent development steps related to modeling of combustion and formation of char and volatiles of various fuel types in CFB conditions. Also a new model for predicting the formation of nitrogen oxides is presented. Validation of mixing and combustion parameters for solids and gases are based on test balances at several large-scale CFB boilers combusting coal, peat and bio-fuels. Field-tests including lateral and vertical furnace profile measurements and characterization of solid materials provides a window for characterization of fuel specific mixing and combustion behavior in CFB furnace at different loads and operation conditions. Measured horizontal gas profiles are projection of balance between fuel mixing and reactions at lower part of furnace and are used together with both lateral temperature profiles at bed and upper parts of furnace for determination of solid mixing and combustion model parameters. Modeling of char and volatile based formation of NO profiles is followed by analysis of oxidizing and reducing regions formed due lower furnace design and mixing characteristics of fuel and combustion airs effecting to formation ofNO furnace profile by reduction and volatile-nitrogen reactions. This paper presents

  7. Characteristics and Efficacy of a New 3-Dimensional Printed Mesh Structure Titanium Alloy Spacer for Posterior Lumbar Interbody Fusion.

    PubMed

    Chung, Sung-Soo; Lee, Kyung-Joon; Kwon, Yoo-Beom; Kang, Kyung-Chung

    2017-08-17

    This study evaluated the characteristics of a newly developed 3-dimensional printed mesh structure titanium spacer and its efficacy for posterior lumbar interbody fusion. Posterior lumbar interbody fusion with this spacer was performed at 53 segments (40 patients; mean age, 64 years; range, 51-73 years). Data were collected prospectively. Radiographic characteristics were analyzed with changes in interbody height, instability of the segments, formation of bone bridges around the implants, and pseudarthrosis, as determined by dynamic radiographs and postoperative computed tomography scans. Clinical outcomes were evaluated with the visual analog scale for the low back and extremities, the Oswestry Disability Index, and the 36-Item Short Form Survey. Radiographically, preoperative anterior and posterior interbody height was significantly increased immediately postoperatively (P<.05), and this increase was maintained until the last follow-up. No segmental motion of 3° or greater was noted at the last follow-up. Sagittal computed tomography images showed complete anterior bone bridges for 94.3% of cases and complete posterior bone bridges for 86.7% of cases. Coronal computed tomography images showed bilateral complete bone bridges for 94.3% of cases and unilateral bone bridges for 5.7% of cases without incomplete bilateral bone bridges. No pseudarthrosis or revision, particularly including posterior lumbar interbody fusion at L5-S1, was noted. Compared with preoperative values, the visual analog scale score for the low back and extremities, the Oswestry Disability Index, and the 36-Item Short Form Survey score showed significant improvement at the last follow-up (P<.05). Posterior lumbar interbody fusion with a newly developed 3-dimensional printed mesh structure titanium spacer showed satisfactory radiographic and clinical results, with no cases of pseudarthrosis or revision, including posterior lumbar interbody fusion at L5-S1. [Orthopedics. 201x; xx

  8. Casting of 3-dimensional footwear prints in snow with foam blocks.

    PubMed

    Petraco, Nicholas; Sherman, Hal; Dumitra, Aurora; Roberts, Marcel

    2016-06-01

    Commercially available foam blocks are presented as an alternative material for the casting and preservation of 3-dimensional footwear impressions located in snow. The method generates highly detailed foam casts of questioned footwear impressions. These casts can be compared to the known outsole standards made from the suspects' footwear. Modification of the commercially available foam casting blocks is simple and fast. The foam block is removed and a piece of cardboard is secured to one side of the block with painter's masking tape. The prepared foam block is then placed back into its original box, marked appropriately, closed and stored until needed. When required the foam block is carefully removed from its storage box and gently placed, foam side down, over the questioned footwear impression. Next, the crime scene technician's hands are placed on top of the cardboard and pressure is gently applied by firmly pressing down onto the impression. The foam cast is removed, dried and placed back into its original container and sealed. The resulting 3D impressions can be directly compared to the outsole of known suspected item(s) of footwear.

  9. Characterization of chemical contaminants generated by a desktop fused deposition modeling 3-dimensional Printer.

    PubMed

    Stefaniak, Aleksandr B; LeBouf, Ryan F; Yi, Jinghai; Ham, Jason; Nurkewicz, Timothy; Schwegler-Berry, Diane E; Chen, Bean T; Wells, J Raymond; Duling, Matthew G; Lawrence, Robert B; Martin, Stephen B; Johnson, Alyson R; Virji, M Abbas

    2017-07-01

    Printing devices are known to emit chemicals into the indoor atmosphere. Understanding factors that influence release of chemical contaminants from printers is necessary to develop effective exposure assessment and control strategies. In this study, a desktop fused deposition modeling (FDM) 3-dimensional (3-D) printer using acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) filaments and two monochrome laser printers were evaluated in a 0.5 m(3) chamber. During printing, chamber air was monitored for vapors using a real-time photoionization detector (results expressed as isobutylene equivalents) to measure total volatile organic compound (TVOC) concentrations, evacuated canisters to identify specific VOCs by off-line gas chromatography-mass spectrometry (GC-MS) analysis, and liquid bubblers to identify carbonyl compounds by GC-MS. Airborne particles were collected on filters for off-line analysis using scanning electron microscopy with an energy dispersive x-ray detector to identify elemental constituents. For 3-D printing, TVOC emission rates were influenced by a printer malfunction, filament type, and to a lesser extent, by filament color; however, rates were not influenced by the number of printer nozzles used or the manufacturer's provided cover. TVOC emission rates were significantly lower for the 3-D printer (49-3552 µg h(-1)) compared to the laser printers (5782-7735 µg h(-1)). A total of 14 VOCs were identified during 3-D printing that were not present during laser printing. 3-D printed objects continued to off-gas styrene, indicating potential for continued exposure after the print job is completed. Carbonyl reaction products were likely formed from emissions of the 3-D printer, including 4-oxopentanal. Ultrafine particles generated by the 3-D printer using ABS and a laser printer contained chromium. Consideration of the factors that influenced the release of chemical contaminants (including known and suspected asthmagens such as styrene

  10. Tracheal suspension by using 3-dimensional printed personalized scaffold in a patient with tracheomalacia

    PubMed Central

    Huang, Lijun; Wang, Lei; He, Jiankang; Zhao, Jinbo; Zhong, Daixing; Yang, Guanying; Guo, Ting; Yan, Xiaolong; Zhang, Lixiang; Li, Dichen

    2016-01-01

    The major methods are used to fix or stabilize the central airways and major bronchi with either anterior suspension and/or posterior fixation for severe tracheomalacia (TM). Many support biomaterials, like mesh and sternal plate, can be used in the surgery. But there are no specialized biomaterials for TM which must be casually fabricated by the doctors in operation. Three dimensional printing (3DP) has currently untapped potential to provide custom, protean devices for challenging and life-threatening disease processes. After meticulous design, we created a polycaprolactone (PCL) scaffold for a female patient with TM, which would support for at least 24 months, to maintain the native lumen size of collapsed airways. Using 4-0 Polyglactin sutures, we grasped and suspended the malacic trachea into the scaffold. A remarkable improvement can be observed in the view of bronchoscope and chest CT after surgery. In the narrowest cavity of malacic trachea, the inner diameter increased from 0.3 to 1.0 cm, and the cross sectional area increased 4–5 times. The patient felt an obvious relief of dyspnea after surgery. In a word, the 3DP PCL scaffold can supply a personalized tool for suspending the malacic trachea in the future. PMID:28066613

  11. High resolution 3-Dimensional imaging of the human cardiac conduction system from microanatomy to mathematical modeling.

    PubMed

    Stephenson, Robert S; Atkinson, Andrew; Kottas, Petros; Perde, Filip; Jafarzadeh, Fatemeh; Bateman, Mike; Iaizzo, Paul A; Zhao, Jichao; Zhang, Henggui; Anderson, Robert H; Jarvis, Jonathan C; Dobrzynski, Halina

    2017-08-03

    Cardiac arrhythmias and conduction disturbances are accompanied by structural remodelling of the specialised cardiomyocytes known collectively as the cardiac conduction system. Here, using contrast enhanced micro-computed tomography, we present, in attitudinally appropriate fashion, the first 3-dimensional representations of the cardiac conduction system within the intact human heart. We show that cardiomyocyte orientation can be extracted from these datasets at spatial resolutions approaching the single cell. These data show that commonly accepted anatomical representations are oversimplified. We have incorporated the high-resolution anatomical data into mathematical simulations of cardiac electrical depolarisation. The data presented should have multidisciplinary impact. Since the rate of depolarisation is dictated by cardiac microstructure, and the precise orientation of the cardiomyocytes, our data should improve the fidelity of mathematical models. By showing the precise 3-dimensional relationships between the cardiac conduction system and surrounding structures, we provide new insights relevant to valvar replacement surgery and ablation therapies. We also offer a practical method for investigation of remodelling in disease, and thus, virtual pathology and archiving. Such data presented as 3D images or 3D printed models, will inform discussions between medical teams and their patients, and aid the education of medical and surgical trainees.

  12. Assessment and Planning for a Pediatric Bilateral Hand Transplant Using 3-Dimensional Modeling: Case Report.

    PubMed

    Gálvez, Jorge A; Gralewski, Kevin; McAndrew, Christine; Rehman, Mohamed A; Chang, Benjamin; Levin, L Scott

    2016-03-01

    Children are not typically considered for hand transplantation for various reasons, including the difficulty of finding an appropriate donor. Matching donor-recipient hands and forearms based on size is critically important. If the donor's hands are too large, the recipient may not be able to move the fingers effectively. Conversely, if the donor's hands are too small, the appearance may not be appropriate. We present an 8-year-old child evaluated for a bilateral hand transplant following bilateral amputation. The recipient forearms and model hands were modeled from computed tomography imaging studies and replicated as anatomic models with a 3-dimensional printer. We modified the scale of the printed hand to produce 3 proportions, 80%, 100% and 120%. The transplant team used the anatomical models during evaluation of a donor for appropriate match based on size. The donor's hand size matched the 100%-scale anatomical model hand and the transplant team was activated. In addition to assisting in appropriate donor selection by the transplant team, the 100%-scale anatomical model hand was used to create molds for prosthetic hands for the donor.

  13. Myocardial Tissue Engineering With Cells Derived From Human-Induced Pluripotent Stem Cells and a Native-Like, High-Resolution, 3-Dimensionally Printed Scaffold.

    PubMed

    Gao, Ling; Kupfer, Molly E; Jung, Jangwook P; Yang, Libang; Zhang, Patrick; Da Sie, Yong; Tran, Quyen; Ajeti, Visar; Freeman, Brian T; Fast, Vladimir G; Campagnola, Paul J; Ogle, Brenda M; Zhang, Jianyi

    2017-04-14

    Conventional 3-dimensional (3D) printing techniques cannot produce structures of the size at which individual cells interact. Here, we used multiphoton-excited 3D printing to generate a native-like extracellular matrix scaffold with submicron resolution and then seeded the scaffold with cardiomyocytes, smooth muscle cells, and endothelial cells that had been differentiated from human-induced pluripotent stem cells to generate a human-induced pluripotent stem cell-derived cardiac muscle patch (hCMP), which was subsequently evaluated in a murine model of myocardial infarction. The scaffold was seeded with ≈50 000 human-induced pluripotent stem cell-derived cardiomyocytes, smooth muscle cells, and endothelial cells (in a 2:1:1 ratio) to generate the hCMP, which began generating calcium transients and beating synchronously within 1 day of seeding; the speeds of contraction and relaxation and the peak amplitudes of the calcium transients increased significantly over the next 7 days. When tested in mice with surgically induced myocardial infarction, measurements of cardiac function, infarct size, apoptosis, both vascular and arteriole density, and cell proliferation at week 4 after treatment were significantly better in animals treated with the hCMPs than in animals treated with cell-free scaffolds, and the rate of cell engraftment in hCMP-treated animals was 24.5% at week 1 and 11.2% at week 4. Thus, the novel multiphoton-excited 3D printing technique produces extracellular matrix-based scaffolds with exceptional resolution and fidelity, and hCMPs fabricated with these scaffolds may significantly improve recovery from ischemic myocardial injury. © 2017 American Heart Association, Inc.

  14. Microcatheter Shaping for Intracranial Aneurysm Coiling Using the 3-Dimensional Printing Rapid Prototyping Technology: Preliminary Result in the First 10 Consecutive Cases.

    PubMed

    Namba, Katsunari; Higaki, Ayuho; Kaneko, Naoki; Mashiko, Toshihiro; Nemoto, Shigeru; Watanabe, Eiju

    2015-07-01

    An optimal microcatheter is necessary for successful coiling of an intracranial aneurysm. The optimal shape may be predetermined before the endovascular surgery via the use of a 3-dimensional (3D) printing rapid prototyping technology. We report a preliminary series of intracranial aneurysms treated with a microcatheter shape determined by the patient's anatomy and configuration of the aneurysm, which was fabricated with a 3D printer aneurysm model. A solid aneurysm model was fabricated with a 3D printer based on the data acquired from the 3D rotational angiogram. A hollow aneurysm model with an identical vessel and aneurysm lumen to the actual anatomy was constructed with use of the solid model as a mold. With use of the solid model, a microcatheter shaping mandrel was formed to identically line the 3D curvature of the parent vessel and the long axis of the aneurysm. With use of the mandrel, a test microcatheter was shaped and validated for the accuracy with the hollow model. All the planning processes were undertaken at least 1 day before treatment. The preshaped mandrel was then applied in the endovascular procedure. Ten consecutive intracranial aneurysms were coiled with the pre-planned shape of the microcatheter and evaluated for the clinical and anatomical outcomes and microcatheter accuracy and stability. All of pre-planned microcatheters matched the vessel and aneurysm anatomy. Seven required no microguidewire assistance in catheterizing the aneurysm whereas 3 required guiding of a microguidewire. All of the microcatheters accurately aligned the long axis of the aneurysm. The pre-planned microcatheter shapes demonstrated stability in all except in 1 large aneurysm case. When a 3D printing rapid type prototyping technology is used, a patient-specific and optimal microcatheter shape may be determined preoperatively. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Promotion of osteointegration under diabetic conditions by tantalum coating-based surface modification on 3-dimensional printed porous titanium implants.

    PubMed

    Wang, Lin; Hu, Xiaofan; Ma, Xiangyu; Ma, Zhensheng; Zhang, Yang; Lu, Yizhao; Li, Xiang; Lei, Wei; Feng, Yafei

    2016-12-01

    Clinical evidence indicates a high failure rate for titanium implants (TiI) in diabetic patients, involving the overproduction of reactive oxygen species (ROS) at the implant/bone interface. Tantalum coating on titanium (TaTi) has exerted better tissue integration properties than TiI, but its biological performance under diabetic conditions remains elusive. To investigate whether TaTi may ameliorate diabetes-induced implant destabilization and the underlying mechanisms, primary rabbit osteoblasts cultured on 3-dimensional printed TiI and TaTi were exposed to normal serum (NS), diabetic serum (DS), DS+NAC (a potent ROS inhibitor), and DS+SB203580 (a specific p38 MAPK inhibitor). An in vivo study was performed on diabetic sheep implanted with TiI or TaTi. Diabetes induced mitochondrial-derived ROS overproduction and caused cellular dysfunction and apoptosis, together with the activation of p38 MAPK in osteoblasts on TiI surface. Importantly, TaTi significantly attenuated ROS production and p38 MAPK phosphorylation and exerted more osseointegrative cell behavior than TiI, as shown by improved osteoblast adhesion, increased cell proliferation and differentiation and decreased apoptosis. These results were confirmed in vivo by the enhanced bone healing efficacy of TaTi. Moreover, treatment with NAC or SB203580 on TiI not only inhibited the activation of p38 MAPK but also improved cell function and alleviated apoptotic injury, whereas TaTi combined with NAC or SB203580 failed to further improve osteoblast functional recovery compared with TaTi alone. These results demonstrated that the tantalum coating markedly improved diabetes-induced impaired osteogenesis of TiI, which may be attributed to the suppression of the ROS-mediated p38 MAPK pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Simultaneous Bimaxillary Surgery and Mandibular Reconstruction With a 3-Dimensional Printed Titanium Implant Fabricated by Electron Beam Melting: A Preliminary Mechanical Testing of the Printed Mandible.

    PubMed

    Lee, Ui-Lyong; Kwon, Jae-Sung; Woo, Su-Heon; Choi, Young-Jun

    2016-07-01

    A woman presented with a long history of mandibular defects posterior to the left lower first premolar caused by inadequate reconstruction after removal of a tumor on the left side of the mandible. In the frontal view, extreme facial asymmetry was apparent. The dental midline of the mandible was deviated 10 mm to the left compared with the dental midline of the maxilla, and all maxillary teeth were inclined to the left owing to dental compensation. There was an 8-mm maxillary occlusal cant relative to the maxillary first molar. Bimaxillary surgery using computer-assisted designed and computer-assisted manufactured devices without an intermediate occlusal splint was performed to align the maxilla and mandible at the correct position, and reconstructive surgery for the mandible using a 3-dimensional printed titanium mandible was concurrently performed. In particular, during the virtual mandible design, 2 abutments that enabled the prosthetic restoration were included in the mandible using a computer-assisted design program. This report describes the successful functional and esthetic reconstruction of the mandible using electron beam melting technology, an alternative technique for reconstruction of mandibles that did not undergo radiation therapy. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  17. En Bloc Resection of Primary Malignant Bone Tumor in the Cervical Spine Based on 3-Dimensional Printing Technology.

    PubMed

    Xiao, Jian-Ru; Huang, Wen-Ding; Yang, Xing-Hai; Yan, Wang-Jun; Song, Dian-Wen; Wei, Hai-Feng; Liu, Tie-Long; Wu, Zhi-Peng; Yang, Cheng

    2016-05-01

    To investigate the feasibility and safety of en bloc resection of cervical primary malignant bone tumors by a combined anterior and posterior approach based on a three-dimensional (3-D) printing model. Five patients with primary malignant bone tumors of the cervical spine underwent en bloc resection via a one-stage combined anteroposterior approach in our hospital from March 2013 to June 2014. They comprised three men and two women of mean age 47.2 years (range, 26-67 years). Three of the tumors were chondrosarcomas and two chordomas. Preoperative 3-D printing models were created by 3-D printing technology. Sagittal en bloc resections were planned based on these models and successfully performed. A 360° reconstruction was performed by spinal instrumentation in all cases. Surgical margins, perioperative complications, local control rate and survival rate were assessed. All patients underwent en bloc excision via a combined posterior and anterior approach in one stage. Mean operative time and estimated blood loss were 465 minutes and 1290 mL, respectively. Mean follow-up was 21 months. Wide surgical margins were achieved in two patients and marginal resection in three; these three patients underwent postoperative adjuvant radiation therapy. One vertebral artery was ligated and sacrificed in each of three patients. Nerve root involved by tumor was sacrificed in three patients with preoperative upper extremity weakness. One patient (Case 3) had significant transient radiculopathy with paresis postoperatively. Another (Case 4) with C 4 and C 5 chordoma had respiratory difficulties and pneumonia after surgery postoperatively. He recovered completely after 2 weeks' management with a tracheotomy tube and antibiotics in the intensive care unit. No cerebrovascular complications and wound infection were observed. No local recurrence or instrumentation failure were detected during follow-up. Though technically challenging, it is feasible and safe to perform en

  18. Combined Inkjet Printing and Infrared Sintering of Silver Nanoparticles using a Swathe-by-Swathe and Layer-by-Layer Approach for 3-Dimensional Structures.

    PubMed

    Vaithilingam, Jayasheelan; Simonelli, Marco; Saleh, Ehab; Senin, Nicola; Wildman, Ricky D; Hague, Richard J M; Leach, Richard K; Tuck, Christopher J

    2017-02-22

    Despite the advancement of additive manufacturing (AM)/3-dimensional (3D) printing, single-step fabrication of multifunctional parts using AM is limited. With the view of enabling multifunctional AM (MFAM), in this study, sintering of metal nanoparticles was performed to obtain conductivity for continuous line inkjet printing of electronics. This was achieved using a bespoke three-dimensional (3D) inkjet-printing machine, JETx, capable of printing a range of materials and utilizing different post processing procedures to print multilayered 3D structures in a single manufacturing step. Multiple layers of silver were printed from an ink containing silver nanoparticles (AgNPs) and infrared sintered using a swathe-by-swathe (SS) and layer-by-layer sintering (LS) regime. The differences in the heat profile for the SS and LS was observed to influence the coalescence of the AgNPs. Void percentage of both SS and LS samples was higher toward the top layer than the bottom layer due to relatively less IR exposure in the top than the bottom. The results depicted a homogeneous microstructure for LS of AgNPs and showed less deformation compared to the SS. Electrical resistivity of the LS tracks (13.6 ± 1 μΩ cm) was lower than the SS tracks (22.5 ± 1 μΩ cm). This study recommends the use of LS method to sinter the AgNPs to obtain a conductive track in 25% less time than SS method for MFAM.

  19. 3-dimensional modeling of transcranial magnetic stimulation: Design and application

    NASA Astrophysics Data System (ADS)

    Salinas, Felipe Santiago

    Over the past three decades, transcranial magnetic stimulation (TMS) has emerged as an effective tool for many research, diagnostic and therapeutic applications in humans. TMS delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this dissertation, we present a thorough examination of the total electric field induced by TMS in air and a realistic head model with clinically relevant coil poses. In the first chapter, a detailed account of TMS coil wiring geometry was shown to provide significant improvements in the accuracy of primary E-field calculations. Three-dimensional models which accounted for the TMS coil's wire width, height, shape and number of turns clearly improved the fit of calculated-to-measured E-fields near the coil body. Detailed primary E-field models were accurate up to the surface of the coil body (within 0.5% of measured values) whereas simple models were often inadequate (up to 32% different from measured). In the second chapter, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3-D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistic head model was used to assess the effect of multiple surfaces on the total E-field. We found that secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes were predominantly between 25% and 45% of the primary E-fields magnitude. The direction of the secondary E

  20. RCS calculations of 3-dimensional objects, modeled by CAD

    NASA Astrophysics Data System (ADS)

    Deleeneer, I.; Schweicher, E.; Barel, A.

    1991-09-01

    All the steps are detailed that one has to perform to enable efficient Radar Cross Section calculation for objects with a complex and general shape. Only cavities are supposed to be nonexistent at this state of the work. Before the actual RCS calculations, preliminary treatments like systematic modeling, Hidden Faces removal, and automatic recognition of reflection and diffraction centers are realized. After the creation of the object's geometry and its adaptation to the direction of the observator, Physical Optics (PO) was used to determine the backscattered field, and Geometrical Theory of Diffraction (GTD) was used to evaluate the diffracted fields. Only monostatic scattering (i.e., backscattering) is considered.

  1. Do-It-Yourself: 3D Models of Hydrogenic Orbitals through 3D Printing

    ERIC Educational Resources Information Center

    Griffith, Kaitlyn M.; de Cataldo, Riccardo; Fogarty, Keir H.

    2016-01-01

    Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely…

  2. Do-It-Yourself: 3D Models of Hydrogenic Orbitals through 3D Printing

    ERIC Educational Resources Information Center

    Griffith, Kaitlyn M.; de Cataldo, Riccardo; Fogarty, Keir H.

    2016-01-01

    Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely…

  3. 3-dimensional current collection model. [of Tethered Satellite System 1

    NASA Technical Reports Server (NTRS)

    Hwang, Kai-Shen; Shiah, A.; Wu, S. T.; Stone, N.

    1992-01-01

    A three-dimensional, time dependent current collection model of a satellite has been developed for the TSS-1 system. The system has been simulated particularly for the Research of Plasma Electrodynamics (ROPE) experiment. The Maxwellian distributed particles with the geomagnetic field effects are applied in this numerical simulation. The preliminary results indicate that a ring current is observed surrounding the satellite in the equatorial plane. This ring current is found between the plasma sheath and the satellite surface and is oscillating with a time scale of approximately 1 microsec. This is equivalent to the electron plasma frequency. An hour glass shape of electron distribution was observed when the viewing direction is perpendicular to the equatorial plane. This result is consistent with previous findings from Linson (1969) and Antoniades et al. (1990). Electrons that are absorbed by the satellite are limited from the background ionosphere as indicated by Parker and Murphy (1967).

  4. Introducing 3-Dimensional Printing of a Human Anatomic Pathology Specimen: Potential Benefits for Undergraduate and Postgraduate Education and Anatomic Pathology Practice.

    PubMed

    Mahmoud, Amr; Bennett, Michael

    2015-08-01

    Three-dimensional (3D) printing, a rapidly advancing technology, is widely applied in fields such as mechanical engineering and architecture. Three-dimensional printing has been introduced recently into medical practice in areas such as reconstructive surgery, as well as in clinical research. Three-dimensionally printed models of anatomic and autopsy pathology specimens can be used for demonstrating pathology entities to undergraduate medical, dental, and biomedical students, as well as for postgraduate training in examination of gross specimens for anatomic pathology residents and pathology assistants, aiding clinicopathological correlation at multidisciplinary team meetings, and guiding reconstructive surgical procedures. To apply 3D printing in anatomic pathology for teaching, training, and clinical correlation purposes. Multicolored 3D printing of human anatomic pathology specimens was achieved using a ZCorp 510 3D printer (3D Systems, Rock Hill, South Carolina) following creation of a 3D model using Autodesk 123D Catch software (Autodesk, Inc, San Francisco, California). Three-dimensionally printed models of anatomic pathology specimens created included pancreatoduodenectomy (Whipple operation) and radical nephrectomy specimens. The models accurately depicted the topographic anatomy of selected specimens and illustrated the anatomic relation of excised lesions to adjacent normal tissues. Three-dimensional printing of human anatomic pathology specimens is achievable. Advances in 3D printing technology may further improve the quality of 3D printable anatomic pathology specimens.

  5. Experimental Validation of Plastic Mandible Models Produced by a “Low-Cost” 3-Dimensional Fused Deposition Modeling Printer

    PubMed Central

    Maschio, Federico; Pandya, Mirali; Olszewski, Raphael

    2016-01-01

    Background The objective of this study was to investigate the accuracy of 3-dimensional (3D) plastic (ABS) models generated using a low-cost 3D fused deposition modelling printer. Material/Methods Two human dry mandibles were scanned with a cone beam computed tomography (CBCT) Accuitomo device. Preprocessing consisted of 3D reconstruction with Maxilim software and STL file repair with Netfabb software. Then, the data were used to print 2 plastic replicas with a low-cost 3D fused deposition modeling printer (Up plus 2®). Two independent observers performed the identification of 26 anatomic landmarks on the 4 mandibles (2 dry and 2 replicas) with a 3D measuring arm. Each observer repeated the identifications 20 times. The comparison between the dry and plastic mandibles was based on 13 distances: 8 distances less than 12 mm and 5 distances greater than 12 mm. Results The mean absolute difference (MAD) was 0.37 mm, and the mean dimensional error (MDE) was 3.76%. The MDE decreased to 0.93% for distances greater than 12 mm. Conclusions Plastic models generated using the low-cost 3D printer UPplus2® provide dimensional accuracies comparable to other well-established rapid prototyping technologies. Validated low-cost 3D printers could represent a step toward the better accessibility of rapid prototyping technologies in the medical field. PMID:27003456

  6. Experimental Validation of Plastic Mandible Models Produced by a "Low-Cost" 3-Dimensional Fused Deposition Modeling Printer.

    PubMed

    Maschio, Federico; Pandya, Mirali; Olszewski, Raphael

    2016-03-22

    The objective of this study was to investigate the accuracy of 3-dimensional (3D) plastic (ABS) models generated using a low-cost 3D fused deposition modelling printer. Two human dry mandibles were scanned with a cone beam computed tomography (CBCT) Accuitomo device. Preprocessing consisted of 3D reconstruction with Maxilim software and STL file repair with Netfabb software. Then, the data were used to print 2 plastic replicas with a low-cost 3D fused deposition modeling printer (Up plus 2®). Two independent observers performed the identification of 26 anatomic landmarks on the 4 mandibles (2 dry and 2 replicas) with a 3D measuring arm. Each observer repeated the identifications 20 times. The comparison between the dry and plastic mandibles was based on 13 distances: 8 distances less than 12 mm and 5 distances greater than 12 mm. The mean absolute difference (MAD) was 0.37 mm, and the mean dimensional error (MDE) was 3.76%. The MDE decreased to 0.93% for distances greater than 12 mm. Plastic models generated using the low-cost 3D printer UPplus2® provide dimensional accuracies comparable to other well-established rapid prototyping technologies. Validated low-cost 3D printers could represent a step toward the better accessibility of rapid prototyping technologies in the medical field.

  7. Simple parameter estimation for complex models — Testing evolutionary techniques on 3-dimensional biogeochemical ocean models

    NASA Astrophysics Data System (ADS)

    Mattern, Jann Paul; Edwards, Christopher A.

    2017-01-01

    Parameter estimation is an important part of numerical modeling and often required when a coupled physical-biogeochemical ocean model is first deployed. However, 3-dimensional ocean model simulations are computationally expensive and models typically contain upwards of 10 parameters suitable for estimation. Hence, manual parameter tuning can be lengthy and cumbersome. Here, we present four easy to implement and flexible parameter estimation techniques and apply them to two 3-dimensional biogeochemical models of different complexities. Based on a Monte Carlo experiment, we first develop a cost function measuring the model-observation misfit based on multiple data types. The parameter estimation techniques are then applied and yield a substantial cost reduction over ∼ 100 simulations. Based on the outcome of multiple replicate experiments, they perform on average better than random, uninformed parameter search but performance declines when more than 40 parameters are estimated together. Our results emphasize the complex cost function structure for biogeochemical parameters and highlight dependencies between different parameters as well as different cost function formulations.

  8. 3-dimensional orthodontics visualization system with dental study models and orthopantomograms

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Ong, S. H.; Foong, K. W. C.; Dhar, T.

    2005-04-01

    The aim of this study is to develop a system that provides 3-dimensional visualization of orthodontic treatments. Dental plaster models and corresponding orthopantomogram (dental panoramic tomogram) are first digitized and fed into the system. A semi-auto segmentation technique is applied to the plaster models to detect the dental arches, tooth interstices and gum margins, which are used to extract individual crown models. 3-dimensional representation of roots, generated by deforming generic tooth models with orthopantomogram using radial basis functions, is attached to corresponding crowns to enable visualization of complete teeth. An optional algorithm to close the gaps between deformed roots and actual crowns by using multi-quadratic radial basis functions is also presented, which is capable of generating smooth mesh representation of complete 3-dimensional teeth. User interface is carefully designed to achieve a flexible system with as much user friendliness as possible. Manual calibration and correction is possible throughout the data processing steps to compensate occasional misbehaviors of automatic procedures. By allowing the users to move and re-arrange individual teeth (with their roots) on a full dentition, this orthodontic visualization system provides an easy and accurate way of simulation and planning of orthodontic treatment. Its capability of presenting 3-dimensional root information with only study models and orthopantomogram is especially useful for patients who do not undergo CT scanning, which is not a routine procedure in most orthodontic cases.

  9. Use of intraoral scanning and 3-dimensional printing in the fabrication of a removable partial denture for a patient with limited mouth opening.

    PubMed

    Wu, Jiang; Li, Yan; Zhang, Yumei

    2017-05-01

    When treating patients with severely limited mouth openings, it is difficult for the dentist to obtain an impression and fabricate a removable partial denture (RPD) by using traditional methods. Intraoral scanning, computer-aided design, and 3-dimensional (3D) printing have provided alternative methods for fabricating dental prostheses. The authors present a case in which they aimed to improve the efficiency and quality of fabricating an RPD framework by integrating the technologies of intraoral scanning, computer-aided design, and 3D printing. Initially, the authors reconstructed the digital cast with multiple intraoral scans. Subsequently, the authors designed the virtual RPD framework. On the basis of the virtual framework, the titanium alloy framework was fabricated by means of a 3D printing process, and the authors fitted the final RPD to the patient. Unlike the traditional method, this integrated system has the potential to design a custom-made dental prosthesis and directly make an RPD framework with complicated patterns. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

  10. A 3-dimensional model for teaching local flaps using porcine skin.

    PubMed

    Hassan, Zahid; Hogg, Fiona; Graham, Ken

    2014-10-01

    The European Working Time Directive and streamlined training has led to reduced training time. Surgery, as an experience-dependent craft specialty is affected more than other medical specialties. Trainees want to maximize all training opportunities in the clinical setting, and having predeveloped basic skills acquired on a simulated model can facilitate this.Here we describe the use of a novel model to design and raise local flaps in the face and scalp regions. The model consists of mannequin heads draped with porcine skin which is skewered with pins at strategic points to give a 3-dimensional model which closely resembles a cadaveric head.The advantages of this model are that it is life size and incorporates all the relevant anatomical features, which can be drawn on if required.This model was used on a recent course, Intermediate Skills in Plastic Surgery: Flaps Around the Face, at the Royal College of Surgeons England. The trainees found that practicing on the porcine skin gave them an opportunity to master the basics of flap design and implementation.In summary, this innovative 3-dimensional training model has received high levels of satisfaction and is currently as close as we can get to cadaveric dissection without the constraints and cost of using human tissue.

  11. Accuracy of 3-dimensional curvilinear measurements on digital models with intraoral scanners.

    PubMed

    Mack, Spencer; Bonilla, Tammy; English, Jeryl D; Cozad, Benjamin; Akyalcin, Sercan

    2017-09-01

    Our objectives were to evaluate and compare the digital dental models generated from 2 commercial intraoral scanners with manual measurements when performing 3-dimensional surface measurements along a curved line (curvilinear). Dry mandibles (n = 61) with intact dentition were used. The mandibles were digitized using 2 chair-side intraoral scanners: Cadent iTero (Align Technology, San Jose, Calif) and Lythos Digital Impression system (Ormco, Orange, Calif). Digitized 3-dimensional models were converted to individual stereolithography files and used with commercial software to obtain the curvilinear measurements. Manual measurements were carried out directly on the mandibular teeth. Measurements were made on different locations on the dental arch in various directions. One-sample t tests and linear regression analyses were performed. To further graphically examine the accuracy between the different methods, Bland-Altman plots were computed. The level of significance was set at P <0.05. There were no significant differences between any of the paired methods; this indicated a certain level of agreement between the methods tested (P >0.05). Bland-Altman analysis showed no fixed bias of 1 approach vs the other, and random errors were detected in all comparisons. Although the mean biases of the digital models obtained by the iTero and Lythos scanners, when compared with direct caliper measurements, were low, the comparison of the 2 intraoral scanners yielded the lowest mean bias. No comparison displayed statistical significance for the t scores; this indicated the absence of proportional bias in these comparisons. The intraoral scanners tested in this study produced digital dental models that were comparatively accurate when performing direct surface measurements along a curved line in 3 dimensions. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  12. 3-Dimensional Geologic Modeling Applied to the Structural Characterization of Geothermal Systems: Astor Pass, Nevada, USA

    SciTech Connect

    Siler, Drew L; Faulds, James E; Mayhew, Brett

    2013-04-16

    Geothermal systems in the Great Basin, USA, are controlled by a variety of fault intersection and fault interaction areas. Understanding the specific geometry of the structures most conducive to broad-scale geothermal circulation is crucial to both the mitigation of the costs of geothermal exploration (especially drilling) and to the identification of geothermal systems that have no surface expression (blind systems). 3-dimensional geologic modeling is a tool that can elucidate the specific stratigraphic intervals and structural geometries that host geothermal reservoirs. Astor Pass, NV USA lies just beyond the northern extent of the dextral Pyramid Lake fault zone near the boundary between two distinct structural domains, the Walker Lane and the Basin and Range, and exhibits characteristics of each setting. Both northwest-striking, left-stepping dextral faults of the Walker Lane and kinematically linked northerly striking normal faults associated with the Basin and Range are present. Previous studies at Astor Pass identified a blind geothermal system controlled by the intersection of west-northwest and north-northwest striking dextral-normal faults. Wells drilled into the southwestern quadrant of the fault intersection yielded 94°C fluids, with geothermometers suggesting a maximum reservoir temperature of 130°C. A 3-dimensional model was constructed based on detailed geologic maps and cross-sections, 2-dimensional seismic data, and petrologic analysis of the cuttings from three wells in order to further constrain the structural setting. The model reveals the specific geometry of the fault interaction area at a level of detail beyond what geologic maps and cross-sections can provide.

  13. Virtual electrophysiological study in a 3-dimensional cardiac magnetic resonance imaging model of porcine myocardial infarction.

    PubMed

    Ng, Jason; Jacobson, Jason T; Ng, Justin K; Gordon, David; Lee, Daniel C; Carr, James C; Goldberger, Jeffrey J

    2012-07-31

    This study sought to test the hypothesis that "virtual" electrophysiological studies (EPS) on an anatomic platform generated by 3-dimensional magnetic resonance imaging reconstruction of the left ventricle can reproduce the reentrant circuits of induced ventricular tachycardia (VT) in a porcine model of myocardial infarction. Delayed-enhancement magnetic resonance imaging has been used to characterize myocardial infarction and "gray zones," which are thought to reflect heterogeneous regions of viable and nonviable myocytes. Myocardial infarction by coronary artery occlusion was induced in 8 pigs. After a recovery period, 3-dimensional cardiac magnetic resonance images were obtained from each pig in vivo. Normal areas, gray zones, and infarct cores were classified based on voxel intensity. In the computer model, gray zones were assigned slower conduction and longer action potential durations than those for normal myocardium. Virtual EPS was performed and compared with results of actual in vivo programmed stimulation and noncontact mapping. The left ventricular volumes ranged from 97.8 to 166.2 cm(3), with 4.9% to 17.5% of voxels classified as infarct zones. Six of the 7 pigs in which VT developed during actual EPS were also inducible with virtual EPS. Four of the 6 pigs that had simulated VT had reentrant circuits that approximated the circuits seen with noncontact mapping, whereas the remaining 2 had similar circuits but propagating in opposite directions. This initial study demonstrates the feasibility of applying a mathematical model to magnetic resonance imaging reconstructions of the left ventricle to predict VT circuits. Virtual EPS may be helpful to plan catheter ablation strategies or to identify patients who are at risk of future episodes of VT. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  14. Photoprotection by pistachio bioactives in a 3-dimensional human skin equivalent tissue model.

    PubMed

    Chen, C-Y Oliver; Smith, Avi; Liu, Yuntao; Du, Peng; Blumberg, Jeffrey B; Garlick, Jonathan

    2017-01-25

    Reactive oxygen species (ROS) generated during ultraviolet (UV) light exposure can induce skin damage and aging. Antioxidants can provide protection against oxidative injury to skin via "quenching" ROS. Using a validated 3-dimensional (3D) human skin equivalent (HSE) tissue model that closely mimics human skin, we examined whether pistachio antioxidants could protect HSE against UVA-induced damage. Lutein and γ-tocopherol are the predominant lipophilic antioxidants in pistachios; treatment with these compounds prior to UVA exposure protected against morphological changes to the epithelial and connective tissue compartments of HSE. Pistachio antioxidants preserved overall skin thickness and organization, as well as fibroblast morphology, in HSE exposed to UVA irradiation. However, this protection was not substantiated by the analysis of the proliferation of keratinocytes and apoptosis of fibroblasts. Additional studies are warranted to elucidate the basis of these discordant results and extend research into the potential role of pistachio bioactives promoting skin health.

  15. Simple computer program to model 3-dimensional underground heat flow with realistic boundary conditions

    NASA Astrophysics Data System (ADS)

    Metz, P. D.

    A FORTRAN computer program called GROCS (GRound Coupled Systems) has been developed to study 3-dimensional underground heat flow. Features include the use of up to 30 finite elements or blocks of Earth which interact via finite difference heat flow equations and a subprogram which sets realistic time and depth dependent boundary conditions. No explicit consideration of mositure movement or freezing is given. GROCS has been used to model the thermal behavior of buried solar heat storage tanks (with and without insulation) and serpentine pipe fields for solar heat pump space conditioning systems. The program is available independently or in a form compatible with specially written TRNSYS component TYPE subroutines. The approach taken in the design of GROCS, the mathematics contained and the program architecture, are described. Then, the operation of the stand-alone version is explained. Finally, the validity of GROCS is discussed.

  16. [Establishment of 3-dimensional finite element model of human knee joint and its biomechanics].

    PubMed

    Yuan, Ping; Wang, Wanchun

    2010-01-01

    To establish a 3-dimensional (3-D) finite element knee model in healthy Chinese males, to verify the validity of the model, and to analyze the biomechanics of this model under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. A set of consecutive transectional computerized tomography images of normal male knee joints in upright weight-bearing position was selected. With image processing and inversion technology, the 3-D finite element model of the normal knee joint was established through the software ABAQOUS/STANDARD Version-6.5.Biomechanical analysis of this model was processed under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. A 3-D finite element model of healthy Chinese males was successfully established. The ranges of motion of varus and valgus were both small and the difference between them has no statistical significance (P>0.05). The motion of internal and external rotation of the knee took place only in flexion situation.The range of motion of external rotation was larger than that of internal rotation in the same knee (P<0.05). The 3-D geometrical model of the knee resembles the actual knee segments. It can imitate the knee response to different loads. This model could be used for further study on knee biomechanics.

  17. A 3-dimensional DTI MRI-based model of GBM growth and response to radiation therapy.

    PubMed

    Hathout, Leith; Patel, Vishal; Wen, Patrick

    2016-09-01

    Glioblastoma (GBM) is both the most common and the most aggressive intra-axial brain tumor, with a notoriously poor prognosis. To improve this prognosis, it is necessary to understand the dynamics of GBM growth, response to treatment and recurrence. The present study presents a mathematical diffusion-proliferation model of GBM growth and response to radiation therapy based on diffusion tensor (DTI) MRI imaging. This represents an important advance because it allows 3-dimensional tumor modeling in the anatomical context of the brain. Specifically, tumor infiltration is guided by the direction of the white matter tracts along which glioma cells infiltrate. This provides the potential to model different tumor growth patterns based on location within the brain, and to simulate the tumor's response to different radiation therapy regimens. Tumor infiltration across the corpus callosum is simulated in biologically accurate time frames. The response to radiation therapy, including changes in cell density gradients and how these compare across different radiation fractionation protocols, can be rendered. Also, the model can estimate the amount of subthreshold tumor which has extended beyond the visible MR imaging margins. When combined with the ability of being able to estimate the biological parameters of invasiveness and proliferation of a particular GBM from serial MRI scans, it is shown that the model has potential to simulate realistic tumor growth, response and recurrence patterns in individual patients. To the best of our knowledge, this is the first presentation of a DTI-based GBM growth and radiation therapy treatment model.

  18. Using Interior Point Method Optimization Techniques to Improve 2- and 3-Dimensional Models of Earth Structures

    NASA Astrophysics Data System (ADS)

    Zamora, A.; Gutierrez, A. E.; Velasco, A. A.

    2014-12-01

    2- and 3-Dimensional models obtained from the inversion of geophysical data are widely used to represent the structural composition of the Earth and to constrain independent models obtained from other geological data (e.g. core samples, seismic surveys, etc.). However, inverse modeling of gravity data presents a very unstable and ill-posed mathematical problem, given that solutions are non-unique and small changes in parameters (position and density contrast of an anomalous body) can highly impact the resulting model. Through the implementation of an interior-point method constrained optimization technique, we improve the 2-D and 3-D models of Earth structures representing known density contrasts mapping anomalous bodies in uniform regions and boundaries between layers in layered environments. The proposed techniques are applied to synthetic data and gravitational data obtained from the Rio Grande Rift and the Cooper Flat Mine region located in Sierra County, New Mexico. Specifically, we improve the 2- and 3-D Earth models by getting rid of unacceptable solutions (those that do not satisfy the required constraints or are geologically unfeasible) given the reduction of the solution space.

  19. The Effectiveness of an Interactive 3-Dimensional Computer Graphics Model for Medical Education

    PubMed Central

    Konishi, Takeshi; Tamura, Yoko; Moriguchi, Hiroki

    2012-01-01

    Background Medical students often have difficulty achieving a conceptual understanding of 3-dimensional (3D) anatomy, such as bone alignment, muscles, and complex movements, from 2-dimensional (2D) images. To this end, animated and interactive 3-dimensional computer graphics (3DCG) can provide better visual information to users. In medical fields, research on the advantages of 3DCG in medical education is relatively new. Objective To determine the educational effectiveness of interactive 3DCG. Methods We divided 100 participants (27 men, mean (SD) age 17.9 (0.6) years, and 73 women, mean (SD) age 18.1 (1.1) years) from the Health Sciences University of Mongolia (HSUM) into 3DCG (n = 50) and textbook-only (control) (n = 50) groups. The control group used a textbook and 2D images, while the 3DCG group was trained to use the interactive 3DCG shoulder model in addition to a textbook. We conducted a questionnaire survey via an encrypted satellite network between HSUM and Tokushima University. The questionnaire was scored on a 5-point Likert scale from strongly disagree (score 1) to strongly agree (score 5). Results Interactive 3DCG was effective in undergraduate medical education. Specifically, there was a significant difference in mean (SD) scores between the 3DCG and control groups in their response to questionnaire items regarding content (4.26 (0.69) vs 3.85 (0.68), P = .001) and teaching methods (4.33 (0.65) vs 3.74 (0.79), P < .001), but no significant difference in the Web category. Participants also provided meaningful comments on the advantages of interactive 3DCG. Conclusions Interactive 3DCG materials have positive effects on medical education when properly integrated into conventional education. In particular, our results suggest that interactive 3DCG is more efficient than textbooks alone in medical education and can motivate students to understand complex anatomical structures. PMID:23611759

  20. The effectiveness of an interactive 3-dimensional computer graphics model for medical education.

    PubMed

    Battulga, Bayanmunkh; Konishi, Takeshi; Tamura, Yoko; Moriguchi, Hiroki

    2012-07-09

    Medical students often have difficulty achieving a conceptual understanding of 3-dimensional (3D) anatomy, such as bone alignment, muscles, and complex movements, from 2-dimensional (2D) images. To this end, animated and interactive 3-dimensional computer graphics (3DCG) can provide better visual information to users. In medical fields, research on the advantages of 3DCG in medical education is relatively new. To determine the educational effectiveness of interactive 3DCG. We divided 100 participants (27 men, mean (SD) age 17.9 (0.6) years, and 73 women, mean (SD) age 18.1 (1.1) years) from the Health Sciences University of Mongolia (HSUM) into 3DCG (n = 50) and textbook-only (control) (n = 50) groups. The control group used a textbook and 2D images, while the 3DCG group was trained to use the interactive 3DCG shoulder model in addition to a textbook. We conducted a questionnaire survey via an encrypted satellite network between HSUM and Tokushima University. The questionnaire was scored on a 5-point Likert scale from strongly disagree (score 1) to strongly agree (score 5). Interactive 3DCG was effective in undergraduate medical education. Specifically, there was a significant difference in mean (SD) scores between the 3DCG and control groups in their response to questionnaire items regarding content (4.26 (0.69) vs 3.85 (0.68), P = .001) and teaching methods (4.33 (0.65) vs 3.74 (0.79), P < .001), but no significant difference in the Web category. Participants also provided meaningful comments on the advantages of interactive 3DCG. Interactive 3DCG materials have positive effects on medical education when properly integrated into conventional education. In particular, our results suggest that interactive 3DCG is more efficient than textbooks alone in medical education and can motivate students to understand complex anatomical structures.

  1. Superimposition of 3-dimensional cone-beam computed tomography models of growing patients

    PubMed Central

    Cevidanes, Lucia H. C.; Heymann, Gavin; Cornelis, Marie A.; DeClerck, Hugo J.; Tulloch, J. F. Camilla

    2009-01-01

    Introduction The objective of this study was to evaluate a new method for superimposition of 3-dimensional (3D) models of growing subjects. Methods Cone-beam computed tomography scans were taken before and after Class III malocclusion orthopedic treatment with miniplates. Three observers independently constructed 18 3D virtual surface models from cone-beam computed tomography scans of 3 patients. Separate 3D models were constructed for soft-tissue, cranial base, maxillary, and mandibular surfaces. The anterior cranial fossa was used to register the 3D models of before and after treatment (about 1 year of follow-up). Results Three-dimensional overlays of superimposed models and 3D color-coded displacement maps allowed visual and quantitative assessment of growth and treatment changes. The range of interobserver errors for each anatomic region was 0.4 mm for the zygomatic process of maxilla, chin, condyles, posterior border of the rami, and lower border of the mandible, and 0.5 mm for the anterior maxilla soft-tissue upper lip. Conclusions Our results suggest that this method is a valid and reproducible assessment of treatment outcomes for growing subjects. This technique can be used to identify maxillary and mandibular positional changes and bone remodeling relative to the anterior cranial fossa. PMID:19577154

  2. Modeling Biofilm-Induced Hydraulic Changes In 3-Dimensional Prefractal Porous Media

    NASA Astrophysics Data System (ADS)

    Kim, J.; Choi, H.; Perfect, E.; Pachepsky, Y. A.

    2008-12-01

    Biofilm-induced clogging is the significant phenomenon in subsurface hydrology that may affect aquifer recharge and solute transport. Modeling biofilm impact on flow and transport at pore scale should include characterization of the heterogeneity of both biofilm and medium. In this study, a numerical model of biofilm- induced hydraulic changes in porous media was developed based on the individual-based model (IbM) for the biofilm growth according to the Monod equation, and the Lattice Boltzmann model (LBM) for the water flow. The LBM was modified to consider biofilm growth in each grid cell, and IbM was synchronized with the LBM. The model behavior was first investigated for simple geometry of the prismatic void space with constant flow and concentration boundary conditions at the inflow boundary, no-gradient condition on the outflow side, and periodic boundary condition on the other sides. The mass conservation was tested by varying Peclet number and computing the solute breakthrough. The breakthrough was retarded when a solid sphere was placed in the prism, and the retardation was increasing as flow velocity was increasing. Increase in the biofilm volume surrounding solid sphere increased pressure at the windward side of sphere, and the flow velocity in the narrow passage between biofilms was increased. The biofilm grew more vigorously on the windward side compared with the leeward side of the sphere because the biofilm growth interrupted the supply of the dissolved substrate to the leeward side. Darcy relation was better to estimate hydraulic conductivity than Kozeny-Carman relation which assumes that biofilms are uniformly distributed on the surface. Finally, 3- dimensional mass and pore-solid prefractal lattices as models of heterogeneous porous media were generated by iterated function system and used as the simulation domain. The flow in these domains reached the steady state at threshold porosities (hydrostatic threshold) that were estimated to be about 0

  3. A 3-dimensional rigid cluster thorax model for kinematic measurements during gait.

    PubMed

    Kiernan, D; Malone, A; O'Brien, T; Simms, C K

    2014-04-11

    The trunk has been shown to work as an active segment rather than a passenger unit during gait and it is felt that trunk kinematics should be given more consideration during gait assessment. While 3-dimensional assessment of the thorax with respect to the pelvis and laboratory can provide a comprehensive description of trunk movement, the majority of existing 3-D thorax models demonstrate shortcomings such as the need for multiple skin marker configurations, difficult landmark identification and practical issues for assessment on female subjects. A small number of studies have used rigid cluster models to quantify thorax movement, however the models and points of attachment are not well described and validation rarely considered. The aim of this study was to propose an alternative rigid cluster 3-D thorax model to quantify movement during gait and provide validation of this model. A rigid mount utilising active markers was developed and applied over the 3rd thoracic vertebra, previously reported as an area of least skin movement artefact on the trunk. The model was compared to two reference thorax models through simultaneous recording during gait on 15 healthy subjects. Excellent waveform similarity was demonstrated between the proposed model and the two reference models (CMC range 0.962-0.997). Agreement of discrete parameters was very-good to excellent. In addition, ensemble average graphs demonstrated almost identical curve displacement between models. The results suggest that the proposed model can be confidently used as an alternative to other thorax models in the clinical setting. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. 3D Printing of Molecular Models

    ERIC Educational Resources Information Center

    Gardner, Adam; Olson, Arthur

    2016-01-01

    Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,…

  5. 3D Printing of Molecular Models

    ERIC Educational Resources Information Center

    Gardner, Adam; Olson, Arthur

    2016-01-01

    Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,…

  6. 3-Dimensional Modeling of Capacitively and Inductively Coupled Plasma Etching Systems

    NASA Astrophysics Data System (ADS)

    Rauf, Shahid

    2008-10-01

    Low temperature plasmas are widely used for thin film etching during micro and nano-electronic device fabrication. Fluid and hybrid plasma models were developed 15-20 years ago to understand the fundamentals of these plasmas and plasma etching. These models have significantly evolved since then, and are now a major tool used for new plasma hardware design and problem resolution. Plasma etching is a complex physical phenomenon, where inter-coupled plasma, electromagnetic, fluid dynamics, and thermal effects all have a major influence. The next frontier in the evolution of fluid-based plasma models is where these models are able to self-consistently treat the inter-coupling of plasma physics with fluid dynamics, electromagnetics, heat transfer and magnetostatics. We describe one such model in this paper and illustrate its use in solving engineering problems of interest for next generation plasma etcher design. Our 3-dimensional plasma model includes the full set of Maxwell equations, transport equations for all charged and neutral species in the plasma, the Navier-Stokes equation for fluid flow, and Kirchhoff's equations for the lumped external circuit. This model also includes Monte Carlo based kinetic models for secondary electrons and stochastic heating, and can take account of plasma chemistry. This modeling formalism allows us to self-consistently treat the dynamics in commercial inductively and capacitively coupled plasma etching reactors with realistic plasma chemistries, magnetic fields, and reactor geometries. We are also able to investigate the influence of the distributed electromagnetic circuit at very high frequencies (VHF) on the plasma dynamics. The model is used to assess the impact of azimuthal asymmetries in plasma reactor design (e.g., off-center pump, 3D magnetic field, slit valve, flow restrictor) on plasma characteristics at frequencies from 2 -- 180 MHz. With Jason Kenney, Ankur Agarwal, Ajit Balakrishna, Kallol Bera, and Ken Collins.

  7. An Innovative 3-dimensional Model of the Epitympanum for Teaching of Middle Ear Anatomy.

    PubMed

    Ng, Chew Lip; Liu, Xuandao; Chee, Shuo Chian Jeremy; Ngo, Raymond Yeow Seng

    2015-11-01

    To facilitate teaching of the anatomy of the epitympanum, we developed and evaluated the effectiveness of an interactive 3-dimensional (3D) computer model that can be viewed from all angles. Questionnaire-based prospective randomized controlled trial. Undergraduate medical education program. The model was created using Google Sketchup, a 3D modeling software. We recruited 72 graduating medical students and randomized them into 2 groups. One group was given the 3D model and reading materials on the epitympanic anatomy (3D group), while the other group relied on reading material and pictures (2-dimensional [2D] group). A questionnaire and anatomy quiz assessed the utility of the 3D model in learning the anatomy of the epitympanum. The mean age of the participants was 22 years. There were no statistically significant differences in demographics and previous experience with 3D models. The 3D group was significantly more confident in its ability to identify structures of the epitympanum on pictures and computed tomography scans when compared to the 2D group. Most participants were in favor of the model as a useful learning tool and preferred to use it with an instructor. In the anatomy quiz, the 3D group fared significantly better, achieving a mean score of 65.1% compared to 32.4% in the 2D group (P < .001). The 3D teaching model of the epitympanum is efficacious in short-term recall. By allowing the learner to visualize relations of the epitympanum from all directions, the model aids in appreciation of anatomy and identifications of structures of this region. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  8. An integrated 3-Dimensional Genome Modeling Engine for data-driven simulation of spatial genome organization

    PubMed Central

    Szałaj, Przemysław; Tang, Zhonghui; Michalski, Paul; Pietal, Michal J.; Luo, Oscar J.; Sadowski, Michał; Li, Xingwang; Radew, Kamen; Ruan, Yijun; Plewczynski, Dariusz

    2016-01-01

    ChIA-PET is a high-throughput mapping technology that reveals long-range chromatin interactions and provides insights into the basic principles of spatial genome organization and gene regulation mediated by specific protein factors. Recently, we showed that a single ChIA-PET experiment provides information at all genomic scales of interest, from the high-resolution locations of binding sites and enriched chromatin interactions mediated by specific protein factors, to the low resolution of nonenriched interactions that reflect topological neighborhoods of higher-order chromosome folding. This multilevel nature of ChIA-PET data offers an opportunity to use multiscale 3D models to study structural-functional relationships at multiple length scales, but doing so requires a structural modeling platform. Here, we report the development of 3D-GNOME (3-Dimensional Genome Modeling Engine), a complete computational pipeline for 3D simulation using ChIA-PET data. 3D-GNOME consists of three integrated components: a graph-distance-based heat map normalization tool, a 3D modeling platform, and an interactive 3D visualization tool. Using ChIA-PET and Hi-C data derived from human B-lymphocytes, we demonstrate the effectiveness of 3D-GNOME in building 3D genome models at multiple levels, including the entire genome, individual chromosomes, and specific segments at megabase (Mb) and kilobase (kb) resolutions of single average and ensemble structures. Further incorporation of CTCF-motif orientation and high-resolution looping patterns in 3D simulation provided additional reliability of potential biologically plausible topological structures. PMID:27789526

  9. An integrated 3-Dimensional Genome Modeling Engine for data-driven simulation of spatial genome organization.

    PubMed

    Szałaj, Przemysław; Tang, Zhonghui; Michalski, Paul; Pietal, Michal J; Luo, Oscar J; Sadowski, Michał; Li, Xingwang; Radew, Kamen; Ruan, Yijun; Plewczynski, Dariusz

    2016-12-01

    ChIA-PET is a high-throughput mapping technology that reveals long-range chromatin interactions and provides insights into the basic principles of spatial genome organization and gene regulation mediated by specific protein factors. Recently, we showed that a single ChIA-PET experiment provides information at all genomic scales of interest, from the high-resolution locations of binding sites and enriched chromatin interactions mediated by specific protein factors, to the low resolution of nonenriched interactions that reflect topological neighborhoods of higher-order chromosome folding. This multilevel nature of ChIA-PET data offers an opportunity to use multiscale 3D models to study structural-functional relationships at multiple length scales, but doing so requires a structural modeling platform. Here, we report the development of 3D-GNOME (3-Dimensional Genome Modeling Engine), a complete computational pipeline for 3D simulation using ChIA-PET data. 3D-GNOME consists of three integrated components: a graph-distance-based heat map normalization tool, a 3D modeling platform, and an interactive 3D visualization tool. Using ChIA-PET and Hi-C data derived from human B-lymphocytes, we demonstrate the effectiveness of 3D-GNOME in building 3D genome models at multiple levels, including the entire genome, individual chromosomes, and specific segments at megabase (Mb) and kilobase (kb) resolutions of single average and ensemble structures. Further incorporation of CTCF-motif orientation and high-resolution looping patterns in 3D simulation provided additional reliability of potential biologically plausible topological structures.

  10. [Constructing 3-dimensional colorized digital dental model assisted by digital photography].

    PubMed

    Ye, Hong-qiang; Liu, Yu-shu; Liu, Yun-song; Ning, Jing; Zhao, Yi-jiao; Zhou, Yong-sheng

    2016-02-18

    To explore a method of constructing universal 3-dimensional (3D) colorized digital dental model which can be displayed and edited in common 3D software (such as Geomagic series), in order to improve the visual effect of digital dental model in 3D software. The morphological data of teeth and gingivae were obtained by intra-oral scanning system (3Shape TRIOS), constructing 3D digital dental models. The 3D digital dental models were exported as STL files. Meanwhile, referring to the accredited photography guide of American Academy of Cosmetic Dentistry (AACD), five selected digital photographs of patients'teeth and gingivae were taken by digital single lens reflex camera (DSLR) with the same exposure parameters (except occlusal views) to capture the color data. In Geomagic Studio 2013, after STL file of 3D digital dental model being imported, digital photographs were projected on 3D digital dental model with corresponding position and angle. The junctions of different photos were carefully trimmed to get continuous and natural color transitions. Then the 3D colorized digital dental model was constructed, which was exported as OBJ file or WRP file which was a special file for software of Geomagic series. For the purpose of evaluating the visual effect of the 3D colorized digital model, a rating scale on color simulation effect in views of patients'evaluation was used. Sixteen patients were recruited and their scores on colored and non-colored digital dental models were recorded. The data were analyzed using McNemar-Bowker test in SPSS 20. Universal 3D colorized digital dental model with better color simulation was constructed based on intra-oral scanning and digital photography. For clinical application, the 3D colorized digital dental models, combined with 3D face images, were introduced into 3D smile design of aesthetic rehabilitation, which could improve the patients' cognition for the esthetic digital design and virtual prosthetic effect. Universal 3D colorized

  11. 3-dimensional bioprinting for tissue engineering applications.

    PubMed

    Gu, Bon Kang; Choi, Dong Jin; Park, Sang Jun; Kim, Min Sup; Kang, Chang Mo; Kim, Chun-Ho

    2016-01-01

    The 3-dimensional (3D) printing technologies, referred to as additive manufacturing (AM) or rapid prototyping (RP), have acquired reputation over the past few years for art, architectural modeling, lightweight machines, and tissue engineering applications. Among these applications, tissue engineering field using 3D printing has attracted the attention from many researchers. 3D bioprinting has an advantage in the manufacture of a scaffold for tissue engineering applications, because of rapid-fabrication, high-precision, and customized-production, etc. In this review, we will introduce the principles and the current state of the 3D bioprinting methods. Focusing on some of studies that are being current application for biomedical and tissue engineering fields using printed 3D scaffolds.

  12. Influence of standardization on the precision (reproducibility) of dental cast analysis with virtual 3-dimensional models.

    PubMed

    Hayashi, Kazuo; Chung, Onejune; Park, Seojung; Lee, Seung-Pyo; Sachdeva, Rohit C L; Mizoguchi, Itaru

    2015-03-01

    Virtual 3-dimensional (3D) models obtained by scanning of physical casts have become an alternative to conventional dental cast analysis in orthodontic treatment. If the precision (reproducibility) of virtual 3D model analysis can be further improved, digital orthodontics could be even more widely accepted. The purpose of this study was to clarify the influence of "standardization" of the target points for dental cast analysis using virtual 3D models. Physical plaster models were also measured to obtain additional information. Five sets of dental casts were used. The dental casts were scanned with R700 (3Shape, Copenhagen, Denmark) and REXCAN DS2 3D (Solutionix, Seoul, Korea) scanners. In this study, 3 system and software packages were used: SureSmile (OraMetrix, Richardson, Tex), Rapidform (Inus, Seoul, Korea), and I-DEAS (SDRC, Milford, Conn). Without standardization, the maximum differences were observed between the SureSmile software and the Rapidform software (0.39 mm ± 0.07). With standardization, the maximum differences were observed between the SureSmile software and measurements with a digital caliper (0.099 mm ± 0.01), and this difference was significantly greater (P <0.05) than the 2 other mean difference values. Furthermore, the results of this study showed that the mean differences "WITH" standardization were significantly lower than those "WITHOUT" standardization for all systems, software packages, or methods. The results showed that elimination of the influence of usability or habituation is important for improving the reproducibility of dental cast analysis. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  13. Fenofibrate inhibits tumour intravasation by several independent mechanisms in a 3-dimensional co-culture model.

    PubMed

    Nguyen, Chi Huu; Huttary, Nicole; Atanasov, Atanas G; Chatuphonprasert, Waranya; Brenner, Stefan; Fristiohady, Adryan; Hong, Junli; Stadler, Serena; Holzner, Silvio; Milovanovic, Daniela; Dirsch, Verena M; Kopp, Brigitte; Saiko, Philipp; Krenn, Liselotte; Jäger, Walter; Krupitza, Georg

    2017-05-01

    Lymph node metastasis of breast cancer is a clinical marker of poor prognosis. Yet, there exist no therapies targeting mechanisms of intravasation into lymphatics. Herein we report on an effect of the antidyslipidemic drug fenofibrate with vasoprotective activity, which attenuates breast cancer intravasation in vitro, and describe the potential mechanisms. To measure intravasation in a 3-dimensional co-culture model MDA-MB231 and MCF-7 breast cancer spheroids were placed on immortalised lymphendothelial cell (LEC) monolayers. This provokes the formation of circular chemorepellent induced defects (CCIDs) in the LEC barrier resembling entry ports for the intravasating tumour. Furthermore, the expression of adhesion molecules ICAM-1, CD31 and FAK was investigated in LECs by western blotting as well as cell-cell adhesion and NF-κB activity by respective assays. In MDA-MB231 cells the activity of CYP1A1 was measured by EROD assay. Fenofibrate inhibited CCID formation in the MDA-MB231/LEC- and MCF-7/LEC models and the activity of NF-κB, which in turn downregulated ICAM-1 in LECs and the adhesion of cancer cells to LECs. Furthermore, CD31 and the activity of FAK were inhibited. In MDA-MB231 cells, fenofibrate attenuated CYP1A1 activity. Combinations with other FDA-approved drugs, which reportedly inhibit different ion channels, attenuated CCID formation additively or synergistically. In summary, fenofibrate inhibited NF-κB and ICAM-1, and inactivated FAK, thereby attenuating tumour intravasation in vitro. A combination with other FDA-approved drugs further improved this effect. Our new concept may lead to a novel therapy for cancer patients.

  14. First Results from a Forward, 3-Dimensional Regional Model of a Transpressional San Andreas Fault System

    NASA Astrophysics Data System (ADS)

    Fitzenz, D. D.; Miller, S. A.

    2001-12-01

    We present preliminary results from a 3-dimensional fault interaction model, with the fault system specified by the geometry and tectonics of the San Andreas Fault (SAF) system. We use the forward model for earthquake generation on interacting faults of Fitzenz and Miller [2001] that incorporates the analytical solutions of Okada [85,92], GPS-constrained tectonic loading, creep compaction and frictional dilatancy [Sleep and Blanpied, 1994, Sleep, 1995], and undrained poro-elasticity. The model fault system is centered at the Big Bend, and includes three large strike-slip faults (each discretized into multiple subfaults); 1) a 300km, right-lateral segment of the SAF to the North, 2) a 200km-long left-lateral segment of the Garlock fault to the East, and 3) a 100km-long right-lateral segment of the SAF to the South. In the initial configuration, three shallow-dipping faults are also included that correspond to the thrust belt sub-parallel to the SAF. Tectonic loading is decomposed into basal shear drag parallel to the plate boundary with a 35mm yr-1 plate velocity, and East-West compression approximated by a vertical dislocation surface applied at the far-field boundary resulting in fault-normal compression rates in the model space about 4mm yr-1. Our aim is to study the long-term seismicity characteristics, tectonic evolution, and fault interaction of this system. We find that overpressured faults through creep compaction are a necessary consequence of the tectonic loading, specifically where high normal stress acts on long straight fault segments. The optimal orientation of thrust faults is a function of the strike-slip behavior, and therefore results in a complex stress state in the elastic body. This stress state is then used to generate new fault surfaces, and preliminary results of dynamically generated faults will also be presented. Our long-term aim is to target measurable properties in or around fault zones, (e.g. pore pressures, hydrofractures, seismicity

  15. 3-Dimensional Marine CSEM Modeling by Employing TDFEM with Parallel Solvers

    NASA Astrophysics Data System (ADS)

    Wu, X.; Yang, T.

    2013-12-01

    In this paper, parallel fulfillment is developed for forward modeling of the 3-Dimensional controlled source electromagnetic (CSEM) by using time-domain finite element method (TDFEM). Recently, a greater attention rises on research of hydrocarbon (HC) reservoir detection mechanism in the seabed. Since China has vast ocean resources, seeking hydrocarbon reservoirs become significant in the national economy. However, traditional methods of seismic exploration shown a crucial obstacle to detect hydrocarbon reservoirs in the seabed with a complex structure, due to relatively high acquisition costs and high-risking exploration. In addition, the development of EM simulations typically requires both a deep knowledge of the computational electromagnetics (CEM) and a proper use of sophisticated techniques and tools from computer science. However, the complexity of large-scale EM simulations often requires large memory because of a large amount of data, or solution time to address problems concerning matrix solvers, function transforms, optimization, etc. The objective of this paper is to present parallelized implementation of the time-domain finite element method for analysis of three-dimensional (3D) marine controlled source electromagnetic problems. Firstly, we established a three-dimensional basic background model according to the seismic data, then electromagnetic simulation of marine CSEM was carried out by using time-domain finite element method, which works on a MPI (Message Passing Interface) platform with exact orientation to allow fast detecting of hydrocarbons targets in ocean environment. To speed up the calculation process, SuperLU of an MPI (Message Passing Interface) version called SuperLU_DIST is employed in this approach. Regarding the representation of three-dimension seabed terrain with sense of reality, the region is discretized into an unstructured mesh rather than a uniform one in order to reduce the number of unknowns. Moreover, high-order Whitney

  16. Dissection of the host-pathogen interaction in human tuberculosis using a bioengineered 3-dimensional model

    PubMed Central

    Tezera, Liku B; Bielecka, Magdalena K; Chancellor, Andrew; Reichmann, Michaela T; Shammari, Basim Al; Brace, Patience; Batty, Alex; Tocheva, Annie; Jogai, Sanjay; Marshall, Ben G; Tebruegge, Marc; Jayasinghe, Suwan N; Mansour, Salah; Elkington, Paul T

    2017-01-01

    Cell biology differs between traditional cell culture and 3-dimensional (3-D) systems, and is modulated by the extracellular matrix. Experimentation in 3-D presents challenges, especially with virulent pathogens. Mycobacterium tuberculosis (Mtb) kills more humans than any other infection and is characterised by a spatially organised immune response and extracellular matrix remodelling. We developed a 3-D system incorporating virulent mycobacteria, primary human blood mononuclear cells and collagen–alginate matrix to dissect the host-pathogen interaction. Infection in 3-D led to greater cellular survival and permitted longitudinal analysis over 21 days. Key features of human tuberculosis develop, and extracellular matrix integrity favours the host over the pathogen. We optimised multiparameter readouts to study emerging therapeutic interventions: cytokine supplementation, host-directed therapy and immunoaugmentation. Each intervention modulates the host-pathogen interaction, but has both beneficial and harmful effects. This methodology has wide applicability to investigate infectious, inflammatory and neoplastic diseases and develop novel drug regimes and vaccination approaches. DOI: http://dx.doi.org/10.7554/eLife.21283.001 PMID:28063256

  17. In vitro 3-dimensional tumor model for radiosensitivity of HPV positive OSCC cell lines.

    PubMed

    Zhang, Mei; Rose, Barbara; Lee, C Soon; Hong, Angela M

    2015-01-01

    The incidence of oropharyngeal squamous cell carcinoma (OSCC) is increasing due to the rising prevalence of human papillomavirus (HPV) positive OSCC. HPV positive OSCC is associated with better outcomes than HPV negative OSCC. Our aim was to explore the possibility that this favorable prognosis is due to the enhanced radiosensitivity of HPV positive OSCC. HPV positive OSCC cell lines were generated from the primary OSCCs of 2 patients, and corresponding HPV positive cell lines generated from nodal metastases following xenografting in nude mice. Monolayer and 3 dimensional (3D) culture techniques were used to compare the radiosensitivity of HPV positive lines with that of 2 HPV negative OSCC lines. Clonogenic and protein assays were used to measure survival post radiation. Radiation induced cell cycle changes were studied using flow cytometry. In both monolayer and 3D culture, HPV positive cells exhibited a heterogeneous appearance whereas HPV negative cells tended to be homogeneous. After irradiation, HPV positive cells had a lower survival in clonogenic assays and lower total protein levels in 3D cultures than HPV negative cells. Irradiated HPV positive cells showed a high proportion of cells in G1/S phase, increased apoptosis, an increased proliferation rate, and an inability to form 3D tumor clumps. In conclusion, HPV positive OSCC cells are more radiosensitive than HPV negative OSCC cells in vitro, supporting a more radiosensitive nature of HPV positive OSCC.

  18. Reconstruction of a mandibular segmental defect with a customized 3-dimensional-printed titanium prosthesis in a cat with a mandibular osteosarcoma.

    PubMed

    Liptak, Julius M; Thatcher, Graham P; Bray, Jonathan P

    2017-04-15

    CASE DESCRIPTION A 12-year-old neutered male domestic shorthair cat had been treated for a mass arising from the lingual aspect of the caudal right mandibular body. Cytoreductive surgery of the mass had been performed twice over a 2-year period, but the mass recurred following both surgeries. The mass was diagnosed as an osteosarcoma, and the cat was referred for further evaluation and treatment. CLINICAL FINDINGS Clinical findings were unremarkable, except for a 2-cm-diameter mass arising from the lingual aspect of the right mandible and mild anemia and lymphopenia. Pre- and postcontrast CT scans of the head, neck, and thorax were performed, revealing that the osteosarcoma was confined to the caudal right mandibular body, with no evidence of lymph node or pulmonary metastasis. TREATMENT AND OUTCOME The stereolithographic files of the CT scan of the head were sent for computer-aided design and manufacture of a customized 3-D-printed titanium prosthesis. Segmental mandibulectomy was performed, and the mandibular defect was reconstructed in a single stage with the 3-D-printed titanium prosthesis. The cat had 1 minor postoperative complication but had no signs of eating difficulties at any point after surgery. The cat was alive and disease free 14 months postoperatively. CLINICAL RELEVANCE Reconstruction of the mandible of a cat following mandibulectomy was possible with computer-aided design and manufacture of a customized 3-D-printed titanium prosthesis. Cats have a high rate of complications following mandibulectomy, and these initial findings suggested that mandibular reconstruction may reduce the risk of these complications and result in a better functional outcome.

  19. Constructing Arguments with 3-D Printed Models

    ERIC Educational Resources Information Center

    McConnell, William; Dickerson, Daniel

    2017-01-01

    In this article, the authors describe a fourth-grade lesson where 3-D printing technologies were not only a stimulus for engagement but also served as a modeling tool providing meaningful learning opportunities. Specifically, fourth-grade students construct an argument that animals' external structures function to support survival in a particular…

  20. Constructing Arguments with 3-D Printed Models

    ERIC Educational Resources Information Center

    McConnell, William; Dickerson, Daniel

    2017-01-01

    In this article, the authors describe a fourth-grade lesson where 3-D printing technologies were not only a stimulus for engagement but also served as a modeling tool providing meaningful learning opportunities. Specifically, fourth-grade students construct an argument that animals' external structures function to support survival in a particular…

  1. Improvement of mechanical strength and osteogenic potential of calcium sulfate-based hydroxyapatite 3-dimensional printed scaffolds by ε-polycarbonate coating.

    PubMed

    Kim, Beom-Su; Yang, Sun-Sik; Park, Ho; Lee, Se-Hwan; Cho, Young-Sam; Lee, Jun

    2017-09-01

    Powder-based three-dimensional (3D) printing is an excellent method to fabricate complex-shaped scaffolds for tissue engineering. However, their lower mechanical strength restricts their application in bone tissue engineering. Here, we created a 3D-printed scaffold coated with a ε-polycaprolactone (PCL) polymer solution (5 and 10 w/v %) to improve the mechanical strength of the scaffold. The 3D scaffold was fabricated from calcium sulfate hemihydrate powder (CaSO4-1/2 H2O), transformed into hydroxyapatite (HAp) by treatment with a hydrothermal reaction in an NH4H2PO4 solution. The surface properties and composition of the scaffold were evaluated using scanning electron microscopy and X-ray diffraction analysis. We demonstrated that the 3D scaffold coated with PCL had an improved mechanical modulus. Coating with 5 and 10% PCL increased the compressive strength significantly, by about 2-fold and 4-fold, respectively, compared with that of uncoated scaffolds. However, the porosity was reduced significantly by coating with 10% PCL. In vitro biological evaluation demonstrated that MG-63 cells adhered well and proliferated on the 3D scaffold coated with PCL, and the scaffold was not cytotoxic. In addition, alkaline phosphatase activity and real time polymerase chain reaction demonstrated that osteoblast differentiation also improved in the PCL-coated 3D scaffolds. These results indicated that PCL polymer coating could improve the compressive strength and biocompatibility of 3D HAp scaffolds for bone tissue engineering applications.

  2. Silk based bioinks for soft tissue reconstruction using 3-dimensional (3D) printing with in vitro and in vivo assessments.

    PubMed

    Rodriguez, María J; Brown, Joseph; Giordano, Jodie; Lin, Samuel J; Omenetto, Fiorenzo G; Kaplan, David L

    2017-02-01

    In the field of soft tissue reconstruction, custom implants could address the need for materials that can fill complex geometries. Our aim was to develop a material system with optimal rheology for material extrusion, that can be processed in physiological and non-toxic conditions and provide structural support for soft tissue reconstruction. To meet this need we developed silk based bioinks using gelatin as a bulking agent and glycerol as a non-toxic additive to induce physical crosslinking. We developed these inks optimizing printing efficacy and resolution for patient-specific geometries that can be used for soft tissue reconstruction. We demonstrated in vitro that the material was stable under physiological conditions and could be tuned to match soft tissue mechanical properties. We demonstrated in vivo that the material was biocompatible and could be tuned to maintain shape and volume up to three months while promoting cellular infiltration and tissue integration.

  3. The Keilson and Storer 3-dimensional (KS-3D) line shape model: applications to optical diagnostic in combustion media

    SciTech Connect

    Joubert, Pierre

    2008-10-22

    High-resolution infrared and Raman spectroscopies require refine spectral line shape model to account for all observed features. For instance, for gaseous mixtures of light molecules with heavy perturbers, drastic changes arise particularly in the collision regime, resulting from the inhomogeneous effects due to the radiator speed-dependence of the collisional line broadening and line shifting parameters. Following our previous work concerning the collision regime, we have developed a new line shape modelization called the Keilson and Storer 3-dimensional line shape model to lower densities, when the Doppler contribution, and the collisional confinement narrowing can be no longer neglected. The consequences for optical diagnostics, particularly for H{sub 2}-N{sub 2} mixtures with high pressure and high temperature are presented. The effects of collisional relaxation on the spectral line shapes are discussed.

  4. Analytical study of twin-jet shielding development of a 3-dimensional model

    NASA Technical Reports Server (NTRS)

    Gerhold, C. H.

    1980-01-01

    The solution for a point source impinging on a cylinder of heated flow is presented. The indefinite integral is solved approximately using a saddle of point method. Comparison of the three-dimensional model to a previously obtained two-dimensional model of twin jet noise indicate the the approximate solution of the integral is valid. The model was analyzed to differentiate among the mechanims of shielding. Zone in which diffraction and transmission dominate are identified. The model was found to compare to experimental shielding results.

  5. Accuracy of stereolithographically printed digital models compared to plaster models.

    PubMed

    Camardella, Leonardo Tavares; Vilella, Oswaldo V; van Hezel, Marleen M; Breuning, Karel H

    2017-03-30

    This study compared the accuracy of plaster models from alginate impressions and printed models from intraoral scanning. A total of 28 volunteers were selected and alginate impressions and intraoral scans were used to make plaster models and digital models of their dentition, respectively. The digital models were printed using a stereolithographic (SLA) 3D printer with a horseshoe-shaped design. Two calibrated examiners measured distances on the plaster and printed models with a digital caliper. The paired t test was used to determine intraobserver error and compare the measurements. The Pearson correlation coefficient was used to evaluate the reliability of measurements for each model type. The measurements on plaster models and printed models show some significant differences in tooth dimensions and interarch parameters, but these differences were not clinically relevant, except for the transversal measurements. The upper and lower intermolar distances on the printed models were statistically significant and clinically relevant smaller. Printed digital models with the SLA 3D printer studied, with a horseshoe-shaped base made from intraoral scans cannot replace conventional plaster models from alginate impressions in orthodontics for diagnosis and treatment planning because of their clinically relevant transversal contraction.

  6. Fast time variations of supernova neutrino signals from 3-dimensional models

    DOE PAGES

    Lund, Tina; Wongwathanarat, Annop; Janka, Hans -Thomas; ...

    2012-11-19

    Here, we study supernova neutrino flux variations in the IceCube detector, using 3D models based on a simplified neutrino transport scheme. The hemispherically integrated neutrino emission shows significantly smaller variations compared with our previous study of 2D models, largely because of the reduced activity of the standing accretion shock instability in this set of 3D models which we interpret as a pessimistic extreme. For the studied cases, intrinsic flux variations up to about 100 Hz frequencies could still be detected in a supernova closer than about 2 kpc.

  7. Visualization of the 3-dimensional flow around a model with the aid of a laser knife

    NASA Technical Reports Server (NTRS)

    Borovoy, V. Y.; Ivanov, V. V.; Orlov, A. A.; Kharchenko, V. N.

    1984-01-01

    A method for visualizing the three-dimensional flow around models of various shapes in a wind tunnel at a Mach number of 5 is described. A laser provides a planar light flux such that any plane through the model can be selectively illuminated. The shape of shock waves and separation regions is then determined by the intensity of light scattered by soot particles in the flow.

  8. Remanent magnetization and 3-dimensional density model of the Kentucky anomaly region

    NASA Technical Reports Server (NTRS)

    Mayhew, M. A.; Estes, R. H.; Myers, D. M.

    1984-01-01

    A three-dimensional model of the Kentucky body was developed to fit surface gravity and long wavelength aeromagnetic data. Magnetization and density parameters for the model are much like those of Mayhew et al (1982). The magnetic anomaly due to the model at satellite altitude is shown to be much too small by itself to account for the anomaly measured by Magsat. It is demonstrated that the source region for the satellite anomaly is considerably more extensive than the Kentucky body sensu stricto. The extended source region is modeled first using prismatic model sources and then using dipole array sources. Magnetization directions for the source region found by inversion of various combinations of scalar and vector data are found to be close to the main field direction, implying the lack of a strong remanent component. It is shown by simulation that in a case (such as this) where the geometry of the source is known, if a strong remanent component is present its direction is readily detectable, but by scalar data as readily as vector data.

  9. A simple, analytic 3-dimensional downburst model based on boundary layer stagnation flow

    NASA Technical Reports Server (NTRS)

    Oseguera, Rosa M.; Bowles, Roland L.

    1988-01-01

    A simple downburst model is developed for use in batch and real-time piloted simulation studies of guidance strategies for terminal area transport aircraft operations in wind shear conditions. The model represents an axisymmetric stagnation point flow, based on velocity profiles from the Terminal Area Simulation System (TASS) model developed by Proctor and satisfies the mass continuity equation in cylindrical coordinates. Altitude dependence, including boundary layer effects near the ground, closely matches real-world measurements, as do the increase, peak, and decay of outflow and downflow with increasing distance from the downburst center. Equations for horizontal and vertical winds were derived, and found to be infinitely differentiable, with no singular points existent in the flow field. In addition, a simple relationship exists among the ratio of maximum horizontal to vertical velocities, the downdraft radius, depth of outflow, and altitude of maximum outflow. In use, a microburst can be modeled by specifying four characteristic parameters, velocity components in the x, y and z directions, and the corresponding nine partial derivatives are obtained easily from the velocity equations.

  10. Accretion Onto Supermassive Black Holes: Observational Signals from 3-Dimensional Disk Models

    NASA Technical Reports Server (NTRS)

    Bromley, Benjamin C.; Miller, Warner A.

    2003-01-01

    Our project was to model accretion flows onto supermassive black holes which reside in the centers of many galaxies. In this report we summarize the results which we obtained with the support of our NASA ATP grant. The scientific results associated with the grant are given in approximately chronological order. We also provide a list of references which acknowledge funding from this grant.

  11. Accretion Onto Supermassive Black Holes: Observational Signals from 3-Dimensional Disk Models

    NASA Technical Reports Server (NTRS)

    Bromley, Benjamin C.; Miller, Warner A.

    2003-01-01

    Our project was to model accretion flows onto supermassive black holes which reside in the centers of many galaxies. In this report we summarize the results which we obtained with the support of our NASA ATP grant. The scientific results associated with the grant are given in approximately chronological order. We also provide a list of references which acknowledge funding from this grant.

  12. 3-dimensional spatially organized PEG-based hydrogels for an aortic valve co-culture model

    PubMed Central

    Puperi, Daniel S.; Balaoing, Liezl R.; O’Connell, Ronan W.; West, Jennifer L.; Grande-Allen, K. Jane

    2015-01-01

    Physiologically relevant in vitro models are needed to study disease progression and to develop and screen potential therapeutic interventions for disease. Heart valve disease, in particular, has no early intervention or non-invasive treatment because there is a lack of understanding the cellular mechanisms which lead to disease. Here, we establish a novel, customizable synthetic hydrogel platform that can be used to study cell-cell interactions and the factors which contribute to valve disease. Spatially localized cell adhesive ligands bound in the scaffold promote cell growth and organization of valve interstitial cells and valve endothelial cells in 3D co-culture. Both cell types maintained phenotypes, homeostatic functions, and produced zonally localized extracellular matrix. This model extends the capabilities of in vitro research by providing a platform to perform direct contact co-culture with cells in their physiologically relevant spatial arrangement. PMID:26241755

  13. A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy

    SciTech Connect

    Solares, Santiago D.

    2015-11-26

    This study introduces a quasi-3-dimensional (Q3D) viscoelastic model and software tool for use in atomic force microscopy (AFM) simulations. The model is based on a 2-dimensional array of standard linear solid (SLS) model elements. The well-known 1-dimensional SLS model is a textbook example in viscoelastic theory but is relatively new in AFM simulation. It is the simplest model that offers a qualitatively correct description of the most fundamental viscoelastic behaviors, namely stress relaxation and creep. However, this simple model does not reflect the correct curvature in the repulsive portion of the force curve, so its application in the quantitative interpretation of AFM experiments is relatively limited. In the proposed Q3D model the use of an array of SLS elements leads to force curves that have the typical upward curvature in the repulsive region, while still offering a very low computational cost. Furthermore, the use of a multidimensional model allows for the study of AFM tips having non-ideal geometries, which can be extremely useful in practice. Examples of typical force curves are provided for single- and multifrequency tappingmode imaging, for both of which the force curves exhibit the expected features. Lastly, a software tool to simulate amplitude and phase spectroscopy curves is provided, which can be easily modified to implement other controls schemes in order to aid in the interpretation of AFM experiments.

  14. A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy.

    PubMed

    Solares, Santiago D

    2015-01-01

    This paper introduces a quasi-3-dimensional (Q3D) viscoelastic model and software tool for use in atomic force microscopy (AFM) simulations. The model is based on a 2-dimensional array of standard linear solid (SLS) model elements. The well-known 1-dimensional SLS model is a textbook example in viscoelastic theory but is relatively new in AFM simulation. It is the simplest model that offers a qualitatively correct description of the most fundamental viscoelastic behaviors, namely stress relaxation and creep. However, this simple model does not reflect the correct curvature in the repulsive portion of the force curve, so its application in the quantitative interpretation of AFM experiments is relatively limited. In the proposed Q3D model the use of an array of SLS elements leads to force curves that have the typical upward curvature in the repulsive region, while still offering a very low computational cost. Furthermore, the use of a multidimensional model allows for the study of AFM tips having non-ideal geometries, which can be extremely useful in practice. Examples of typical force curves are provided for single- and multifrequency tapping-mode imaging, for both of which the force curves exhibit the expected features. Finally, a software tool to simulate amplitude and phase spectroscopy curves is provided, which can be easily modified to implement other controls schemes in order to aid in the interpretation of AFM experiments.

  15. A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy

    DOE PAGES

    Solares, Santiago D.

    2015-11-26

    This study introduces a quasi-3-dimensional (Q3D) viscoelastic model and software tool for use in atomic force microscopy (AFM) simulations. The model is based on a 2-dimensional array of standard linear solid (SLS) model elements. The well-known 1-dimensional SLS model is a textbook example in viscoelastic theory but is relatively new in AFM simulation. It is the simplest model that offers a qualitatively correct description of the most fundamental viscoelastic behaviors, namely stress relaxation and creep. However, this simple model does not reflect the correct curvature in the repulsive portion of the force curve, so its application in the quantitative interpretationmore » of AFM experiments is relatively limited. In the proposed Q3D model the use of an array of SLS elements leads to force curves that have the typical upward curvature in the repulsive region, while still offering a very low computational cost. Furthermore, the use of a multidimensional model allows for the study of AFM tips having non-ideal geometries, which can be extremely useful in practice. Examples of typical force curves are provided for single- and multifrequency tappingmode imaging, for both of which the force curves exhibit the expected features. Lastly, a software tool to simulate amplitude and phase spectroscopy curves is provided, which can be easily modified to implement other controls schemes in order to aid in the interpretation of AFM experiments.« less

  16. 3-dimensional numerical modeling of an industrial radio frequency heating system using finite elements.

    PubMed

    Chan, T V Chow Ting; Tang, J; Younce, F

    2004-01-01

    This paper presents a new, yet simple and effective approach to modeling industrial Radio Frequency heating systems, using the wave equation applied in three dimensions instead of the conventional electrostatics method. The central idea is that the tank oscillatory circuit is excited using an external source. This then excites the applicator circuit which is then used to heat or dry the processed load. Good agreement was obtained between the experimental and numerical data, namely the S11-parameter, phase, and heating patterns for different sized loads and positions.

  17. Goddard Institute for Space Studies (GISS) 3-Dimensional (3-D) Global Tracer Transport Model

    DOE Data Explorer

    Fung, I.

    1993-01-01

    This directory contains the input files used in simulations of atmospheric CO2 using the GISS 3-D global tracer transport model. The directory contains 16 files including a help file (CO2FUNG.HLP), 12 files containing monthly exchanges with vegetation and soils (CO2VEG.JAN . . . DEC), 1 file containing releases of CO2 from fossil fuel burning (CO2FOS.MRL), 1 file containing releases of CO2 from land transformations (CO2DEF.HOU), and 1 file containing the patterns of CO2 exchange with the oceans (CO2OCN.TAK).

  18. 3-DIMENSIONAL Geometric Survey and Structural Modelling of the Dome of Pisa Cathedral

    NASA Astrophysics Data System (ADS)

    Aita, D.; Barsotti, R.; Bennati, S.; Caroti, G.; Piemonte, A.

    2017-02-01

    This paper aims to illustrate the preliminary results of a research project on the dome of Pisa Cathedral (Italy). The final objective of the present research is to achieve a deep understanding of the structural behaviour of the dome, through a detailed knowledge of its geometry and constituent materials, and by taking into account historical and architectural aspects as well. A reliable survey of the dome is the essential starting point for any further investigation and adequate structural modelling. Examination of the status quo on the surveys of the Cathedral dome shows that a detailed survey suitable for structural analysis is in fact lacking. For this reason, high-density and high-precision surveys have been planned, by considering that a different survey output is needed, according both to the type of structural model chosen and purposes to be achieved. Thus, both range-based (laser scanning) and image-based (3D Photogrammetry) survey methodologies have been used. This contribution introduces the first results concerning the shape of the dome derived from surveys. Furthermore, a comparison is made between such survey outputs and those available in the literature.

  19. Modelling Polymer Deformation during 3D Printing

    NASA Astrophysics Data System (ADS)

    McIlroy, Claire; Olmsted, Peter

    Three-dimensional printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The fused deposition modelling technique involves melting a thermoplastic, followed by layer-by-layer extrusion to fabricate an object. The key to ensuring strength at the weld between layers is successful inter-diffusion. However, prior to welding, both the extrusion process and the cooling temperature profile can significantly deform the polymer micro-structure and, consequently, how well the polymers are able to ``re-entangle'' across the weld. In particular, polymer alignment in the flow can cause de-bonding of the layers and create defects. We have developed a simple model of the non-isothermal extrusion process to explore the effects that typical printing conditions and material rheology have on the conformation of a polymer melt. In particular, we incorporate both stretch and orientation using the Rolie-Poly constitutive equation to examine the melt structure as it flows through the nozzle, the subsequent alignment with the build plate and the resulting deformation due to the fixed nozzle height, which is typically less than the nozzle radius.

  20. Evaluation of 3-Dimensional Superimposition Techniques on Various Skeletal Structures of the Head Using Surface Models

    PubMed Central

    Pazera, Pawel; Zorkun, Berna; Katsaros, Christos; Ludwig, Björn

    2015-01-01

    Objectives To test the applicability, accuracy, precision, and reproducibility of various 3D superimposition techniques for radiographic data, transformed to triangulated surface data. Methods Five superimposition techniques (3P: three-point registration; AC: anterior cranial base; AC + F: anterior cranial base + foramen magnum; BZ: both zygomatic arches; 1Z: one zygomatic arch) were tested using eight pairs of pre-existing CT data (pre- and post-treatment). These were obtained from non-growing orthodontic patients treated with rapid maxillary expansion. All datasets were superimposed by three operators independently, who repeated the whole procedure one month later. Accuracy was assessed by the distance (D) between superimposed datasets on three form-stable anatomical areas, located on the anterior cranial base and the foramen magnum. Precision and reproducibility were assessed using the distances between models at four specific landmarks. Non parametric multivariate models and Bland-Altman difference plots were used for analyses. Results There was no difference among operators or between time points on the accuracy of each superimposition technique (p>0.05). The AC + F technique was the most accurate (D<0.17 mm), as expected, followed by AC and BZ superimpositions that presented similar level of accuracy (D<0.5 mm). 3P and 1Z were the least accurate superimpositions (0.790.05), the detected structural changes differed significantly between different techniques (p<0.05). Bland-Altman difference plots showed that BZ superimposition was comparable to AC, though it presented slightly higher random error. Conclusions Superimposition of 3D datasets using surface models created from voxel data can provide accurate, precise, and reproducible results, offering also high efficiency and increased post-processing capabilities. In

  1. Longitudinal evaluation of dental arch asymmetry in Class II subdivision malocclusion with 3-dimensional digital models.

    PubMed

    Veli, Ilknur; Yuksel, Burcin; Uysal, Tancan

    2014-06-01

    Class II subdivision malocclusions with their asymmetric occlusal relationships often pose treatment difficulties. The aim of this study was to evaluate the longitudinal changes of dental arch asymmetry in untreated subjects with Class II subdivision malocclusion. From 706 files from the University of Michigan Growth Study, longitudinal records of 17 untreated subjects with Class II subdivision malocclusion were included this study. Dental arch changes at 3 consecutive longitudinal intervals, defined by the cervical vertebral maturation method, were analyzed on digital dental models. The average ages of the subjects were 12.4, 15.1, and 19.1 years at the 3 time periods, respectively. Maxillary and mandibular reference lines were constructed and used for the intra-arch asymmetry measurements. The Friedman test and analysis of variance with repeated measures were used to determine dental arch asymmetries at the P <0.05 level. All subjects were found to have a type 1 Class II subdivision malocclusion characterized by distal positioning of the mandibular first molar on the Class II side. No statistically significant intra-arch asymmetry changes were found for the maxillary and mandibular dental arches in any time period. Between the baseline and the final follow-up, the data indicated decreases in maxillary and mandibular intercanine arch widths and arch lengths symmetrically. The results of this study indicate that the dental arch asymmetry in patients with Class II subdivision malocclusions did not improve or worsen with growth. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  2. Reconstituted 3-dimensional human skin as a novel in vitro model for studies of carcinogenesis.

    PubMed

    Zhao, J F; Zhang, Y J; Kubilus, J; Jin, X H; Santella, R M; Athar, M; Wang, Z Y; Bickers, D R

    1999-01-08

    EpiDerm (MatTek Co., MA) is a reconstituted human skin equivalent which exhibits morphological and growth characteristics similar to human skin. This model has previously been utilized to evaluate the cytotoxicity and irritant potential of various cosmetic and household products. In this study, we show for the first time that EpiDerm can be used successfully to evaluate the genotoxicity of different types of known carcinogenic agents such as benzo[a]pyrene (BaP), ultraviolet B radiation (UVB), ultraviolet A radiation (UVA), and psoralen-ultraviolet A radiation (PUVA) at the molecular level. The topical application of 50 microg/cm2 BaP to EpiDerm resulted in the accumulation of BaP-DNA adducts and c-fos and p53 proteins as evidenced by immunohistochemical localization. Similarly, exposure to UVB (50 mJ/cm2) and UVA (2.5 J/cm2) enhanced the epidermal expression of c-fos and p53 proteins in the human skin equivalent. PUVA treatment of EpiDerm, however, resulted in the formation of both DNA-8-MOP adducts and augmented expression of c-fos and p53 proteins. Most of these changes reached a peak 8 h after the treatments except in the case of UVA where maximum changes in the expression of c-fos and p53 proteins were observed 24 h after treatment. These results are similar to those previously reported in human and murine skin following exposure to BaP, UVB, UVA, or PUVA indicating that human skin equivalents can be used as a convenient and cost-effective alternative to animal testing for assessing the genotoxicity and mechanism of action of mutagens/carcinogens in human skin. Copyright 1999 Academic Press.

  3. Global simulation of canopy scale sun-induced chlorophyll fluorescence with a 3 dimensional radiative transfer model

    NASA Astrophysics Data System (ADS)

    Kobayashi, H.; Yang, W.; Ichii, K.

    2015-12-01

    Global simulation of canopy scale sun-induced chlorophyll fluorescence with a 3 dimensional radiative transfer modelHideki Kobayashi, Wei Yang, and Kazuhito IchiiDepartment of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology3173-25, Showa-machi, Kanazawa-ku, Yokohama, Japan.Plant canopy scale sun-induced chlorophyll fluorescence (SIF) can be observed from satellites, such as Greenhouse gases Observation Satellite (GOSAT), Orbiting Carbon Observatory-2 (OCO-2), and Global Ozone Monitoring Experiment-2 (GOME-2), using Fraunhofer lines in the near infrared spectral domain [1]. SIF is used to infer photosynthetic capacity of plant canopy [2]. However, it is not well understoond how the leaf-level SIF emission contributes to the top of canopy directional SIF because SIFs observed by the satellites use the near infrared spectral domain where the multiple scatterings among leaves are not negligible. It is necessary to quantify the fraction of emission for each satellite observation angle. Absorbed photosynthetically active radiation of sunlit leaves are 100 times higher than that of shaded leaves. Thus, contribution of sunlit and shaded leaves to canopy scale directional SIF emission should also be quantified. Here, we show the results of global simulation of SIF using a 3 dimensional radiative transfer simulation with MODIS atmospheric (aerosol optical thickness) and land (land cover and leaf area index) products and a forest landscape data sets prepared for each land cover category. The results are compared with satellite-based SIF (e.g. GOME-2) and the gross primary production empirically estimated by FLUXNET and remote sensing data.

  4. Evaluation of pharyngeal airway space changes after bimaxillary orthognathic surgery with a 3-dimensional simulation and modeling program.

    PubMed

    Gokce, Sila Mermut; Gorgulu, Serkan; Gokce, Hasan Suat; Bengi, Ali Osman; Karacayli, Umit; Ors, Fatih

    2014-10-01

    The aims of this study were to use 3-dimensional simulation and modeling programs to evaluate the effects of bimaxillary orthognathic surgical correction of Class III malocclusions on pharyngeal airway space volume, and to compare them with the changes in obstructive sleep apnea measurements from polysomnography. Twenty-five male patients (mean age, 21.6 years) with mandibular prognathism were treated with bilateral sagittal split osteotomy and LeFort I advancement. Polysomnography and computed tomography were performed before surgery and 1.4 ± 0.2 years after surgery. All computed tomography data were transferred to a computer, and the pharyngeal airway space was segmented using SimPlant OMS (Materialise Medical, Leuven, Belgium) programs. The pretreatment and posttreatment pharyngeal airway space determinants in volumetric, linear distance, and cross-sectional measurements, and polysomnography changes were compared with the paired samples t test. Pearson correlation was used to analyze the association between the computed tomography and polysomnography measurements. The results indicated that setback procedures produce anteroposterior narrowing of the pharyngeal airway space at the oropharyngeal and hypopharyngeal levels and the middle and inferior pharyngeal volumes (P <0.05). In contrast, advancement of the maxilla causes widening of the airway in the nasopharyngeal and retropalatal dimensions and increases the superior pharyngeal volume (P <0.05). Distinctively, bimaxillary orthognathic surgery induces significant increases in the total airway volume and the transverse dimensions of all airway areas (P <0.05). Significant correlations were found between the measurements on the computed tomography scans and crucial polysomnography parameters. Bimaxillary orthognathic surgery for correction of Class III malocclusion caused an increase of the total airway volume and improvement of polysomnography parameters. A proposed treatment plan can be modified

  5. Is a 3-Dimensional Stress Balance Ice-Stream Model Really Better Than a 2-Dimensional "Reduced Order" Ice-Stream Model?

    NASA Astrophysics Data System (ADS)

    Sergienko, O.; Macayeal, D. R.

    2007-12-01

    With growing observational awareness of numerous ice-stream processes occurring on short time and spatial scales, e.g., sub-ice-stream lake volume changes and grounding-line sediment wedge build-up, the question of how well models based on "reduced-order" dynamics can simulate ice-stream behavior becomes paramount. Reduced-order models of ice-streams are typically 2-dimensional, and capture only the largest-magnitude terms in the stress tensor (with other terms being constrained by various assumptions). In predicting the overall magnitude and large-scale pattern of ice-stream flow, the reduced-order models appear to be adequate. Efforts underway in the Glaciological Community to create 3-dimensional models of the "full" ice-stream stress balance, which relax the assumptions associated with reduced-order models, suggest that a cost/benefit analysis should be done to determine how likely these efforts will be fruitful. To assess the overall benefits of full 3-dimensional models in relation to the simpler 2-dimensional counterparts, we present model solutions of the full Stokes equations for ice-stream flow over a variety of basal perturbations (e.g., a sticky spot, a subglacial lake, a grounding line). We also present the solutions derived from reduced 2-dimensional models, and compare the two solutions to estimate effects of simplifications and neglected terms, as well as to advise on what circumstances 3-dimensional models are preferable to 2-dimensional models.

  6. A 3-dimensional human embryonic stem cell (hESC)-derived model to detect developmental neurotoxicity of nanoparticles.

    PubMed

    Hoelting, Lisa; Scheinhardt, Benjamin; Bondarenko, Olesja; Schildknecht, Stefan; Kapitza, Marion; Tanavde, Vivek; Tan, Betty; Lee, Qian Yi; Mecking, Stefan; Leist, Marcel; Kadereit, Suzanne

    2013-04-01

    Nanoparticles (NPs) have been shown to accumulate in organs, cross the blood-brain barrier and placenta, and have the potential to elicit developmental neurotoxicity (DNT). Here, we developed a human embryonic stem cell (hESC)-derived 3-dimensional (3-D) in vitro model that allows for testing of potential developmental neurotoxicants. Early central nervous system PAX6(+) precursor cells were generated from hESCs and differentiated further within 3-D structures. The 3-D model was characterized for neural marker expression revealing robust differentiation toward neuronal precursor cells, and gene expression profiling suggested a predominantly forebrain-like development. Altered neural gene expression due to exposure to non-cytotoxic concentrations of the known developmental neurotoxicant, methylmercury, indicated that the 3-D model could detect DNT. To test for specific toxicity of NPs, chemically inert polyethylene NPs (PE-NPs) were chosen. They penetrated deep into the 3-D structures and impacted gene expression at non-cytotoxic concentrations. NOTCH pathway genes such as HES5 and NOTCH1 were reduced in expression, as well as downstream neuronal precursor genes such as NEUROD1 and ASCL1. FOXG1, a patterning marker, was also reduced. As loss of function of these genes results in severe nervous system impairments in mice, our data suggest that the 3-D hESC-derived model could be used to test for Nano-DNT.

  7. Relating electrophotographic printing model and ISO13660 standard attributes

    NASA Astrophysics Data System (ADS)

    Barney Smith, Elisa H.

    2010-01-01

    A mathematical model of the electrophotographic printing process has been developed. This model can be used for analysis. From this a print simulation process has been developed to simulate the effects of the model components on toner particle placement. A wide variety of simulated prints are produced from the model's three main inputs, laser spread, charge to toner proportionality factor and toner particle size. While the exact placement of toner particles is a random process, the total effect is not. The effect of each model parameter on the ISO 13660 print quality attributes line width, fill, raggedness and blurriness is described.

  8. A Novel 3 Dimensional Stromal-based Model for In Vitro Chemotherapy Sensitivity Testing of Leukemia Cells

    PubMed Central

    Aljitawi, Omar S.; Li, Dandan; Xiao, Yinghua; Zhang, Da; Ramachandran, Karthik; Stehno-Bittel, Lisa; Van Veldhuizen, Peter; Lin, Tara L.; Kambhampati, Suman; Garimella, Rama

    2014-01-01

    The disparate responses of leukemia cells to chemotherapy in vivo, compared to in vitro, is partly related to the interactions of leukemic cells and the 3 dimensional (3D) bone marrow stromal microenvironment. We investigated the effects of chemotherapy agents on leukemic cell lines co-cultured with human bone marrow mesenchymal stem cell (hu-BM-MSC) in 3D. Comparison was made to leukemic cells treated in suspension, or grown on a hu-BM-MSC monolayer (2D conditions). We demonstrated that leukemic cells cultured in 3D were more resistant to drug-induced apoptosis compared to cells cultured in 2D or in suspension. We also demonstrated significant differences in leukemic cell response to chemotherapy using different leukemic cell lines cultured in 3D. We suggest that the differential responses to chemotherapy in 3D may be related to the expression of N-cadherin in the co-culture system. This unique model provides an opportunity to study leukemic cell responses to chemotherapy in 3D. PMID:23566162

  9. A 3-Dimensional Numerical Modelling Study on the Effects of Different Stress Regimes on the Magnitude of Induced Seismic Events

    NASA Astrophysics Data System (ADS)

    Amini, A.; Eberhardt, E.

    2016-12-01

    Producing oil and gas from shale reservoirs requires permeability enhancement treatments. This is achieved by injecting fluid under pressure to either propagate cracks through the rock (hydraulic fracture) or to stimulate slip across pre-existing fractures (hydroshear), which allows gas or oil to flow more readily into the well bore. After treatment is performed, the fluid is disposed of by injecting it back into the ground. The injection of these fluids, whether related to permeability enhancement or waste water disposal , into deep formations serves to create localized increases in pore pressures and reductions in the effective normal stresses acting on critically stressed faults, resulting in induced earthquakes. There have been numerous reports of anomalous seismic events with high magnitudes felt on surface that have given rise to public concerns. However, it must be recognized that different producing fields in Canada and the U.S. are situated in different tectonic regimes that favour different fault slip mechanisms. This study will explore the importance of stress regime, comparing the generation of induced seismicity under thrust versus strike slip conditions, with focus on their respective magnitudes distributions. To do so, we will first study empirical data pertaining to recorded seismicity related to hydraulic fracture operations with respect to source mechanisms and magnitude distributions. These will be analyzed in parallel with a series of advanced 3-dimensional numerical models using the distinct element code 3DEC to simulate fault slip under different stress regimes.

  10. Mycoplasma genitalium Infection Activates Cellular Host Defense and Inflammation Pathways in a 3-Dimensional Human Endocervical Epithelial Cell Model

    PubMed Central

    McGowin, Chris L.; Radtke, Andrea L.; Abraham, Kyle; Martin, David H.; Herbst-Kralovetz, Melissa

    2013-01-01

    Background. Because Mycoplasma genitalium is a prevalent and emerging cause of sexually transmitted infections, understanding the mechanisms by which M. genitalium elicits mucosal inflammation is an essential component to managing lower and upper reproductive tract disease syndromes in women. Methods. We used a rotating wall vessel bioreactor system to create 3-dimensional (3-D) epithelial cell aggregates to model and assess endocervical infection by M. genitalium. Results. Attachment of M. genitalium to the host cell's apical surface was observed directly and confirmed using immunoelectron microscopy. Bacterial replication was observed from 0 to 72 hours after inoculation, during which time host cells underwent ultrastructural changes, including reduction of microvilli, and marked increases in secretory vesicle formation. Using genome-wide transcriptional profiling, we identified a host defense and inflammation signature activated by M. genitalium during acute infection (48 hours after inoculation) that included cytokine and chemokine activity and secretion of factors for antimicrobial defense. Multiplex bead-based protein assays confirmed secretion of proinflammatory cytokines, several of which are involved in leukocyte recruitment and hypothesized to enhance susceptibility to human immunodeficiency type 1 infection. Conclusions. These findings provide insight into key molecules and pathways involved in innate recognition of M. genitalium and the response to acute infection in the human endocervix. PMID:23493725

  11. A Geometric Modelling Approach to Determining the Best Sensing Coverage for 3-Dimensional Acoustic Target Tracking in Wireless Sensor Networks

    PubMed Central

    Pashazadeh, Saeid; Sharifi, Mohsen

    2009-01-01

    Existing 3-dimensional acoustic target tracking methods that use wired/wireless networked sensor nodes to track targets based on four sensing coverage do not always compute the feasible spatio-temporal information of target objects. To investigate this discrepancy in a formal setting, we propose a geometric model of the target tracking problem alongside its equivalent geometric dual model that is easier to solve. We then study and prove some properties of dual model by exploiting its relationship with algebra. Based on these properties, we propose a four coverage axis line method based on four sensing coverage and prove that four sensing coverage always yields two dual correct answers; usually one of them is infeasible. By showing that the feasible answer can be only sometimes identified by using a simple time test method such as the one proposed by ourselves, we prove that four sensing coverage fails to always yield the feasible spatio-temporal information of a target object. We further prove that five sensing coverage always gives the feasible position of a target object under certain conditions that are discussed in this paper. We propose three extensions to four coverage axis line method, namely, five coverage extent point method, five coverage extended axis lines method, and five coverage redundant axis lines method. Computation and time complexities of all four proposed methods are equal in the worst cases as well as on average being equal to Θ(1) each. Proposed methods and proved facts about capabilities of sensing coverage degree in this paper can be used in all other methods of acoustic target tracking like Bayesian filtering methods. PMID:22423198

  12. Assessment and Treatment of Peritumoral Cortical Veins in Parasagittal Meningiomas with Application of 3-Dimensional Imaging Fusion Model.

    PubMed

    Yin, Tengkun; Gu, Jianjun; Huang, Yinxing; Wei, Liangfeng; Gao, Jinxi; Wang, Shousen

    2017-08-01

    Operation of cortical veins is the keystone of parasagittal meningioma (PSM) resection. Little is known about pathologic changes of the veins and proper treatment. We built 3-dimensional (3D) image fusion models by neuronavigation to analyze the features of peritumoral cortical veins for PSMs and explore intraoperative treatment options. We performed a prospective study of 42 consecutive surgically treated PSM patients who underwent preoperative evaluation of peritumoral cortical veins using a 3D venous-tumor fusion model established by a neuronavigation system. We categorized cortical veins into 3 types: single-end anastomosis (type a), tumor-to-end anastomosis (type b), and end-to-end anastomosis (type c). We present surgical strategies to operate these veins. Preoperative evaluation demonstrated 39 patients with peritumoral cortical veins. The 3D models show 100% of the veins (95 in total), which were confirmed intraoperation. The postoperative complication rates after vein injury were 60% (type a), 16.7% (type c), and 0% (type b). Ten patients (23.8%) had residual tumor because of venous protection (equal to Simpson grade III). After correlation analysis, type b and c cortical veins were positively correlated with tumor volume. The anastomoses of cortical veins may provide compensation for venous transaction. There may be a time-evolution relationship between different cortical veins (type a to c to b). Treatment of cortical veins should follow the following principles: single-end veins must be protected, tumor-to-end veins should be transacted directly, and end-to-end veins could be cut selectivity based on the degree of occlusion of the superior sagittal sinus. Detailed preoperative assessment of peritumoral cortical veins is critical for proper treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Femoral Graft-Tunnel Angles in Posterior Cruciate Ligament Reconstruction: Analysis with 3-Dimensional Models and Cadaveric Experiments

    PubMed Central

    Kim, Sung-Jae; Chun, Yong-Min; Moon, Hong-Kyo; Jang, Jae-Won

    2013-01-01

    Purpose The purpose of this study was to compare four graft-tunnel angles (GTA), the femoral GTA formed by three different femoral tunneling techniques (the outside-in, a modified inside-out technique in the posterior sag position with knee hyperflexion, and the conventional inside-out technique) and the tibia GTA in 3-dimensional (3D) knee flexion models, as well as to examine the influence of femoral tunneling techniques on the contact pressure between the intra-articular aperture of the femoral tunnel and the graft. Materials and Methods Twelve cadaveric knees were tested. Computed tomography scans were performed at different knee flexion angles (0°, 45°, 90°, and 120°). Femoral and tibial GTAs were measured at different knee flexion angles on the 3D knee models. Using pressure sensitive films, stress on the graft of the angulation of the femoral tunnel aperture was measured in posterior cruciate ligament reconstructed cadaveric knees. Results Between 45° and 120° of knee flexion, there were no significant differences between the outside-in and modified inside-out techniques. However, the femoral GTA for the conventional inside-out technique was significantly less than that for the other two techniques (p<0.001). In cadaveric experiments using pressure-sensitive film, the maximum contact pressure for the modified inside-out and outside-in technique was significantly lower than that for the conventional inside-out technique (p=0.024 and p=0.017). Conclusion The conventional inside-out technique results in a significantly lesser GTA and higher stress at the intra-articular aperture of the femoral tunnel than the outside-in technique. However, the results for the modified inside-out technique are similar to those for the outside-in technique. PMID:23709438

  14. Development and Application of a 3-Dimensional Finite Element Model for Remediation Wellfield Management at Lawrence Livermore National Laboratory

    NASA Astrophysics Data System (ADS)

    Mansoor, K.; Maley, M. P.; Demir, Z.; Noyes, C.

    2001-12-01

    Lawrence Livermore National Laboratory (LLNL), which is on the Superfund National Priorities List, is implementing an extensive ground water remediation program. The environmental investigation covers an area of about 2 square miles, and is underlain by a thick sequence of heterogeneous alluvial sediments. These sediments have been subdivided into hydrostratigraphic units (HSUs) bounded by thin confining layers that were identified using a deterministic approach. LLNL currently operates a large ground water extraction system that includes 80 ground water extraction wells connected to 25 separate treatment facilities. These combined facilities treated about 308 million gallons of ground water at an average combined flow rate of 600 gpm, and removed about 270 kg of volatile organic compounds (VOC's). To better manage this large complex remediation system, a 3-dimensional, finite-element numerical model was developed using FEFLOW. The model simulated a 7 square-mile portion of the large Livermore Valley ground water basin. The quality of the input data varied from highly detailed, in the environmental investigation areas, to sparse, near some of the model domain boundaries. These different data sets had to be integrated to obtain the necessary boundary conditions and input parameters for the model. Hydraulic conductivities were averaged from measured lithologic descriptions and hydraulic test data. Boundary conditions were based on a local and regional assessment of groundwater elevation data representative of observed inflow/outflow boundaries. The model was initially calibrated to a set of 8 distinct hydrologic stress periods over 12 years. Initial flow calibration for the model was achieved using the parameter estimation tool PEST. Through successive data analysis and calibration, optimal parameters were established for each HSU and expanded to 35 hydrologic stress periods covering the entire recorded hydrologic history. VOC transport was calibrated to 9 years of

  15. A 3-Dimensional Model of Water-Bearing Sequences in the Dominguez Gap Region, Long Beach, California

    USGS Publications Warehouse

    Ponti, Daniel J.; Ehman, Kenneth D.; Edwards, Brian D.; Tinsley, John C.; Hildenbrand, Thomas; Hillhouse, John W.; Hanson, Randall T.; McDougall, Kristen; Powell, Charles L.; Wan, Elmira; Land, Michael; Mahan, Shannon; Sarna-Wojcicki, Andrei M.

    2007-01-01

    A 3-dimensional computer model of the Quaternary sequence stratigraphy in the Dominguez gap region of Long Beach, California has been developed to provide a robust chronostratigraphic framework for hydrologic and tectonic studies. The model consists of 13 layers within a 16.5 by 16.1 km (10.25 by 10 mile) square area and extends downward to an altitude of -900 meters (-2952.76 feet). Ten sequences of late Pliocene to Holocene age are identified and correlated within the model. Primary data to build the model comes from five reference core holes, extensive high-resolution seismic data obtained in San Pedro Bay, and logs from several hundred water and oil wells drilled in the region. The model is best constrained in the vicinity of the Dominguez gap seawater intrusion barrier where a dense network of subsurface data exist. The resultant stratigraphic framework and geologic structure differs significantly from what has been proposed in earlier studies. An important new discovery from this approach is the recognition of ongoing tectonic deformation throughout nearly all of Quaternary time that has impacted the geometry and character of the sequences. Anticlinal folding along a NW-SE trend, probably associated with Quaternary reactivation of the Wilmington anticline, has uplifted and thinned deposits along the fold crest, which intersects the Dominguez gap seawater barrier near Pacific Coast Highway. A W-NW trending fault system that approximately parallels the fold crest has also been identified. This fault progressively displaces all but the youngest sequences down to the north and serves as the southern termination of the classic Silverado aquifer. Uplift and erosion of fining-upward paralic sequences along the crest of the young fold has removed or thinned many of the fine-grained beds that serve to protect the underlying Silverado aquifer from seawater contaminated shallow groundwater. As a result of this process, the potential exists for vertical migration of

  16. Markov source model for printed music decoding

    NASA Astrophysics Data System (ADS)

    Kopec, Gary E.; Chou, Philip A.; Maltz, David A.

    1995-03-01

    This paper describes a Markov source model for a simple subset of printed music notation. The model is based on the Adobe Sonata music symbol set and a message language of our own design. Chord imaging is the most complex part of the model. Much of the complexity follows from a rule of music typography that requires the noteheads for adjacent pitches to be placed on opposite sides of the chord stem. This rule leads to a proliferation of cases for other typographic details such as dot placement. We describe the language of message strings accepted by the model and discuss some of the imaging issues associated with various aspects of the message language. We also point out some aspects of music notation that appear problematic for a finite-state representation. Development of the model was greatly facilitated by the duality between image synthesis and image decoding. Although our ultimate objective was a music image model for use in decoding, most of the development proceeded by using the evolving model for image synthesis, since it is computationally far less costly to image a message than to decode an image.

  17. V-stand--a versatile surgical platform for oromandibular reconstruction using a 3-dimensional virtual modeling system.

    PubMed

    Reiser, Vadim; Alterman, Michael; Shuster, Amir; Kleinman, Shlomi; Shlomi, Benjamin; Yanko-Arzi, Ravit; Zaretski, Arik; Amir, Aharon; Fliss, Dan M

    2015-06-01

    The challenge of oromandibular reconstruction (OMR) after oncologic resections has been repeatedly addressed in the literature. Although final oncologic margins can be decided only during surgery, various attempts have been made to create an ideal and accurate platform for OMR. The purpose of this article is to present the V-stand, a versatile surgical platform for OMR using a 3-dimensional (3D) virtual modeling system. Seventeen patients requiring an OMR were included in the study. A presurgical computed tomogram was obtained and virtual resection and reconstruction with a free fibular flap were planned using 3D virtual surgery software. The mandible was reconstructed intraoperatively using the V-stand, which served as a template for the lower border of the mandible and the lateral aspects of the stand were fixed to the proximal mandibular segments using 2-mm titanium screws. Patients' average age was 53 years (5 to 72 yr). Median follow-up was 19 months (2 to 35 months). All reconstructed mandibles resulted in good function and esthetics. The V-stand offers a safe and time-efficient method for OMR. It provides an excellent means for accurate spatial positioning of a fibular free flap. The V-stand preserves the original dimensions of the reconstructed mandible and can overcome surgical ablation modifications because it is not dependent on the precision of the resection, but rather provides a mold for the entire mandible. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Reflectance and transmittance model for recto-verso halftone prints.

    PubMed

    Hébert, Mathieu; Hersch, Roger David

    2006-10-01

    We propose a spectral prediction model for predicting the reflectance and transmittance of recto-verso halftone prints. A recto-verso halftone print is modeled as a diffusing substrate surrounded by two inked interfaces in contact with air (or with another medium). The interaction of light with the print comprises three components: (a) the attenuation of the incident light penetrating the print across the inked interface, (b) the internal reflectance and internal transmittance that accounts for the substrate's intrinsic reflectance and transmittance and for the multiple Fresnel internal reflections at the inked interfaces, and (c) the attenuation of light exiting the print across the inked interfaces. Both the classical Williams-Clapper and Clapper-Yule spectral prediction models are special cases of the proposed recto-verso reflectance and transmittance model. We also extend the Kubelka-Munk model to predict the reflectance and transmittance of recto-verso halftone prints. The extended Kubelka-Munk model is compatible with the proposed recto-verso reflectance and transmittance model. In the case of a homogeneous substrate, the recto-verso model's internal reflectance and transmittance can be expressed as a function Kubelka-Munk's scattering and absorption parameters, or the Kubelka-Munk's scattering and absorption parameters can be inferred from the recto-verso model's internal reflectance and transmittance, deduced from spectral measurements. The proposed model offers new perspectives both for spectral transmission and reflection predictions and for characterizing the properties of printed diffuse substrates.

  19. Use of 3-Dimensional Volumetric Modeling of Adrenal Gland Size in Patients with Primary Pigmented Nodular Adrenocortical Disease.

    PubMed

    Chrysostomou, P P; Lodish, M B; Turkbey, E B; Papadakis, G Z; Stratakis, C A

    2016-04-01

    Primary pigmented nodular adrenocortical disease (PPNAD) is a rare type of bilateral adrenal hyperplasia leading to hypercortisolemia. Adrenal nodularity is often appreciable with computed tomography (CT); however, accurate radiologic characterization of adrenal size in PPNAD has not been studied well. We used 3-dimensional (3D) volumetric analysis to characterize and compare adrenal size in PPNAD patients, with and without Cushing's syndrome (CS). Patients diagnosed with PPNAD and their family members with known mutations in PRKAR1A were screened. CT scans were used to create 3D models of each adrenal. Criteria for biochemical diagnosis of CS included loss of diurnal variation and/or elevated midnight cortisol levels, and paradoxical increase in urinary free cortisol and/or urinary 17-hydroxysteroids after dexamethasone administration. Forty-five patients with PPNAD (24 females, 27.8±17.6 years) and 8 controls (19±3 years) were evaluated. 3D volumetric modeling of adrenal glands was performed in all. Thirty-eight patients out of 45 (84.4%) had CS. Their mean adrenal volume was 8.1 cc±4.1, 7.2 cc±4.5 (p=0.643) for non-CS, and 8.0cc±1.6 for controls. Mean values were corrected for body surface area; 4.7 cc/kg/m(2)±2.2 for CS, and 3.9 cc/kg/m(2)±1.3 for non-CS (p=0.189). Adrenal volume and midnight cortisol in both groups was positively correlated, r=0.35, p=0.03. We conclude that adrenal volume measured by 3D CT in patients with PPNAD and CS was similar to those without CS, confirming empirical CT imaging-based observations. However, the association between adrenal volume and midnight cortisol levels may be used as a marker of who among patients with PPNAD may develop CS, something that routine CT cannot do.

  20. Assessing agreement in measurements of orthodontic study models: Digital caliper on plaster models vs 3-dimensional software on models scanned by structured-light scanner.

    PubMed

    Wan Hassan, Wan Nurazreena; Othman, Siti Adibah; Chan, Chee Seng; Ahmad, Roshahida; Ali, Siti Nor'Ain; Abd Rohim, Anis

    2016-11-01

    In this study we aimed to compare measurements on plaster models using a digital caliper, and on 3-dimensional (3D) digital models, produced using a structured-light scanner, using 3D software. Fifty digital models were scanned from the same plaster models. Arch and tooth size measurements were made by 2 operators, twice. Calibration was done on 10 sets of models and checked using the Pearson correlation coefficient. Data were analyzed by error variances, repeatability coefficient, repeated-measures analysis of variance, and Bland-Altman plots. Error variances ranged between 0.001 and 0.044 mm for the digital caliper method, and between 0.002 and 0.054 mm for the 3D software method. Repeated-measures analysis of variance showed small but statistically significant differences (P <0.05) between the repeated measurements in the arch and buccolingual planes (0.011 and 0.008 mm, respectively). There were no statistically significant differences between methods and between operators. Bland-Altman plots showed that the mean biases were close to zero, and the 95% limits of agreement were within ±0.50 mm. Repeatability coefficients for all measurements were similar. Measurements made on models scanned by the 3D structured-light scanner were in good agreement with those made on conventional plaster models and were, therefore, clinically acceptable. Copyright © 2016. Published by Elsevier Inc.

  1. 3D Modeling Techniques for Print and Digital Media

    NASA Astrophysics Data System (ADS)

    Stephens, Megan Ashley

    In developing my thesis, I looked to gain skills using ZBrush to create 3D models, 3D scanning, and 3D printing. The models created compared the hearts of several vertebrates and were intended for students attending Comparative Vertebrate Anatomy. I used several resources to create a model of the human heart and was able to work from life while creating heart models from other vertebrates. I successfully learned ZBrush and 3D scanning, and successfully printed 3D heart models. ZBrush allowed me to create several intricate models for use in both animation and print media. The 3D scanning technique did not fit my needs for the project, but may be of use for later projects. I was able to 3D print using two different techniques as well.

  2. From medical imaging data to 3D printed anatomical models.

    PubMed

    Bücking, Thore M; Hill, Emma R; Robertson, James L; Maneas, Efthymios; Plumb, Andrew A; Nikitichev, Daniil I

    2017-01-01

    Anatomical models are important training and teaching tools in the clinical environment and are routinely used in medical imaging research. Advances in segmentation algorithms and increased availability of three-dimensional (3D) printers have made it possible to create cost-efficient patient-specific models without expert knowledge. We introduce a general workflow that can be used to convert volumetric medical imaging data (as generated by Computer Tomography (CT)) to 3D printed physical models. This process is broken up into three steps: image segmentation, mesh refinement and 3D printing. To lower the barrier to entry and provide the best options when aiming to 3D print an anatomical model from medical images, we provide an overview of relevant free and open-source image segmentation tools as well as 3D printing technologies. We demonstrate the utility of this streamlined workflow by creating models of ribs, liver, and lung using a Fused Deposition Modelling 3D printer.

  3. From medical imaging data to 3D printed anatomical models

    PubMed Central

    Hill, Emma R.; Robertson, James L.; Maneas, Efthymios; Plumb, Andrew A.; Nikitichev, Daniil I.

    2017-01-01

    Anatomical models are important training and teaching tools in the clinical environment and are routinely used in medical imaging research. Advances in segmentation algorithms and increased availability of three-dimensional (3D) printers have made it possible to create cost-efficient patient-specific models without expert knowledge. We introduce a general workflow that can be used to convert volumetric medical imaging data (as generated by Computer Tomography (CT)) to 3D printed physical models. This process is broken up into three steps: image segmentation, mesh refinement and 3D printing. To lower the barrier to entry and provide the best options when aiming to 3D print an anatomical model from medical images, we provide an overview of relevant free and open-source image segmentation tools as well as 3D printing technologies. We demonstrate the utility of this streamlined workflow by creating models of ribs, liver, and lung using a Fused Deposition Modelling 3D printer. PMID:28562693

  4. Normal growth and development of the lips: a 3-dimensional study from 6 years to adulthood using a geometric model

    PubMed Central

    FERRARIO, VIRGILIO F.; SFORZA, CHIARELLA; SCHMITZ, JOHANNES H.; CIUSA, VERONICA; COLOMBO, ANNA

    2000-01-01

    A 3-dimensional computerised system with landmark representation of the soft-tissue facial surface allows noninvasive and fast quantitative study of facial growth. The aims of the present investigation were (1) to provide reference data for selected dimensions of lips (linear distances and ratios, vermilion area, volume); (2) to quantify the relevant growth changes; and (3) to evaluate sex differences in growth patterns. The 3-dimensional coordinates of 6 soft-tissue landmarks on the lips were obtained by an optoelectronic instrument in a mixed longitudinal and cross-sectional study (2023 examinations in 1348 healthy subjects between 6 y of age and young adulthood). From the landmarks, several linear distances (mouth width, total vermilion height, total lip height, upper lip height), the vermilion height-to-mouth width ratio, some areas (vermilion of the upper lip, vermilion of the lower lip, total vermilion) and volumes (upper lip volume, lower lip volume, total lip volume) were calculated and averaged for age and sex. Male values were compared with female values by means of Student's t test. Within each age group all lip dimensions (distances, areas, volumes) were significantly larger in boys than in girls (P < 0.05), with some exceptions in the first age groups and coinciding with the earlier female growth spurt, whereas the vermilion height-to-mouth width ratio did not show a corresponding sexual dimorphism. Linear distances in girls had almost reached adult dimensions in the 13–14 y age group, while in boys a large increase was still to occur. The attainment of adult dimensions was faster in the upper than in the lower lip, especially in girls. The method used in the present investigation allowed the noninvasive evaluation of a large sample of nonpatient subjects, leading to the definition of 3-dimensional normative data. Data collected in the present study could represent a data base for the quantitative description of human lip morphology from childhood to

  5. Verification and transfer of thermal pollution model. Volume 3: Verification of 3-dimensional rigid-lid model

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.; Sinha, S. K.

    1982-01-01

    The six-volume report: describes the theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth (e.g., natural or man-made inland lakes) because surface elevation has been removed as a parameter. These models allow computation of time-dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions. The free-surface model also provides surface height variations with time.

  6. Verification and transfer of thermal pollution model. Volume 2: User's manual for 3-dimensional free-surface model

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Tuann, S. Y.; Lee, C. R.

    1982-01-01

    The six-volume report: describes the theory of a three-dimensional (3-D) mathematical thermal discharge model and a related one-dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth. These models allow computation of time-dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions.

  7. ABSTRACTION OF INFORMATION FROM 2- AND 3-DIMENSIONAL PORFLOW MODELS INTO A 1-D GOLDSIM MODEL - 11404

    SciTech Connect

    Taylor, G.; Hiergesell, R.

    2010-11-16

    The Savannah River National Laboratory has developed a 'hybrid' approach to Performance Assessment modeling which has been used for a number of Performance Assessments. This hybrid approach uses a multi-dimensional modeling platform (PorFlow) to develop deterministic flow fields and perform contaminant transport. The GoldSim modeling platform is used to develop the Sensitivity and Uncertainty analyses. Because these codes are performing complementary tasks, it is incumbent upon them that for the deterministic cases they produce very similar results. This paper discusses two very different waste forms, one with no engineered barriers and one with engineered barriers, each of which present different challenges to the abstraction of data. The hybrid approach to Performance Assessment modeling used at the SRNL uses a 2-D unsaturated zone (UZ) and a 3-D saturated zone (SZ) model in the PorFlow modeling platform. The UZ model consists of the waste zone and the unsaturated zoned between the waste zone and the water table. The SZ model consists of source cells beneath the waste form to the points of interest. Both models contain 'buffer' cells so that modeling domain boundaries do not adversely affect the calculation. The information pipeline between the two models is the contaminant flux. The domain contaminant flux, typically in units of moles (or Curies) per year from the UZ model is used as a boundary condition for the source cells in the SZ. The GoldSim modeling component of the hybrid approach is an integrated UZ-SZ model. The model is a 1-D representation of the SZ, typically 1-D in the UZ, but as discussed below, depending on the waste form being analyzed may contain pseudo-2-D elements. A waste form at the Savannah River Site (SRS) which has no engineered barriers is commonly referred to as a slit trench. A slit trench, as its name implies, is an unlined trench, typically 6 m deep, 6 m wide, and 200 m long. Low level waste consisting of soil, debris, rubble, wood

  8. Thermo-mechanical Characterization of Metal/Polymer Composite Filaments and Printing Parameter Study for Fused Deposition Modeling in the 3D Printing Process

    NASA Astrophysics Data System (ADS)

    Hwang, Seyeon; Reyes, Edgar I.; Moon, Kyoung-sik; Rumpf, Raymond C.; Kim, Nam Soo

    2015-03-01

    New metal/polymer composite filaments for fused deposition modeling (FDM) processes were developed in order to observe the thermo-mechanical properties of the new filaments. The acrylonitrile butadiene styrene (ABS) thermoplastic was mixed with copper and iron particles. The percent loading of the metal powder was varied to confirm the effects of metal particles on the thermo-mechanical properties of the filament, such as tensile strength and thermal conductivity. The printing parameters such as temperature and fill density were also varied to see the effects of the parameters on the tensile strength of the final product which was made with the FDM process. As a result of this study, it was confirmed that the tensile strength of the composites is decreased by increasing the loading of metal particles. Additionally, the thermal conductivity of the metal/polymer composite filament was improved by increasing the metal content. It is believed that the metal/polymer filament could be used to print metal and large-scale 3-dimensional (3D) structures without any distortion by the thermal expansion of thermoplastics. The material could also be used in 3D printed circuits and electromagnetic structures for shielding and other applications.

  9. Study of materials and machines for 3D printed large-scale, flexible electronic structures using fused deposition modeling

    NASA Astrophysics Data System (ADS)

    Hwang, Seyeon

    The 3 dimensional printing (3DP), called to additive manufacturing (AM) or rapid prototyping (RP), is emerged to revolutionize manufacturing and completely transform how products are designed and fabricated. A great deal of research activities have been carried out to apply this new technology to a variety of fields. In spite of many endeavors, much more research is still required to perfect the processes of the 3D printing techniques especially in the area of the large-scale additive manufacturing and flexible printed electronics. The principles of various 3D printing processes are briefly outlined in the Introduction Section. New types of thermoplastic polymer composites aiming to specified functional applications are also introduced in this section. Chapter 2 shows studies about the metal/polymer composite filaments for fused deposition modeling (FDM) process. Various metal particles, copper and iron particles, are added into thermoplastics polymer matrices as the reinforcement filler. The thermo-mechanical properties, such as thermal conductivity, hardness, tensile strength, and fracture mechanism, of composites are tested to figure out the effects of metal fillers on 3D printed composite structures for the large-scale printing process. In Chapter 3, carbon/polymer composite filaments are developed by a simple mechanical blending process with an aim of fabricating the flexible 3D printed electronics as a single structure. Various types of carbon particles consisting of multi-wall carbon nanotube (MWCNT), conductive carbon black (CCB), and graphite are used as the conductive fillers to provide the thermoplastic polyurethane (TPU) with improved electrical conductivity. The mechanical behavior and conduction mechanisms of the developed composite materials are observed in terms of the loading amount of carbon fillers in this section. Finally, the prototype flexible electronics are modeled and manufactured by the FDM process using Carbon/TPU composite filaments and

  10. Halftone color prints: dot gain and modeling of color distributions

    NASA Astrophysics Data System (ADS)

    Wedin, Mikael; Kruse, Bjoern

    1995-04-01

    The properties of the total printing transfer function are studied using halftone test prints and automatic analysis of the acquired data. a method for determining the dot gain, both physical and optical, based on the colorimetric properties of the halftone dots is presented. To estimate the physical dot gain the method identifies the ink and discriminates between the different colors and the paper using normalized color distributions for each printing ink. The color distribution idea is based on the fact that between the colorimetric centers of gravity (in CIELAB color coordinates), the possible colors of the print are almost one dimensionally distributed. This has been established through three dimensional visualizations of the color gamut for different printers and also for news print. In this approach a simulation how light is scattered in the paper is used to complement the measurement of optical dot gain. Using digital image processing and data modeling through Singular Value Decomposition, properties of the color distributions for halftone prints are identified. The properties are identified by examining the basis functions corresponding to the largest singular values. Links to the physical properties of the ink and the paper are discussed.

  11. Average 3-dimensional models for the comparison of Orbscan II and Pentacam pachymetry maps in normal corneas.

    PubMed

    Bourges, Jean-Louis; Alfonsi, Nicolas; Laliberté, Jean-François; Chagnon, Miguel; Renard, Gilles; Legeais, Jean-Marc; Brunette, Isabelle

    2009-11-01

    To assess the reliability of Orbscan (Bausch & Lomb, Salt Lake City, UT) and Pentacam (Oculus, Wetzlar, Germany) central corneal thickness (CCT) and peripheral corneal thickness (PCT) measurements based on 2 methodologies. Evaluation of a diagnostic technology. Thirty healthy volunteers were recruited prospectively at the Department of Ophthalmology of the Hôtel-Dieu Hospital, Paris, France. Central corneal thickness and PCT were assessed, using ultrasound pachymetry (USP) as the gold standard. Two methodologies were used: (1) the traditional analysis of pachymetry data from 1 central and 8 peripheral reference positions on the cornea, and (2) a 3-dimensional (3-D) analysis based on average corneal pachymetry maps constructed for each system (Orbscan, Pentacam, and USP), each operator (operators 1 and 2), and each visit (visits A and B). Repeatability, intersystem reproducibility, interoperator reproducibility, reproducibility over time, and accuracy of Orbscan and Pentacam CCT and PCT measurements. Distribution and statistical significance of the differences between 3-D average maps. Repeatability (Orbscan intraclass correlation coefficients [ICCs], 0.967-0.992; Pentacam ICCs, 0.986-0.997), interoperator reproducibility, and reproducibility over time (ICCs, 0.976-0.997) were excellent to almost perfect for both systems. Intersystem agreement was almost perfect for CCT (ICC, 0.980), but less strong for PCT (ICCs, 0.928-0.979). Despite a good to excellent agreement between the optical systems and USP (ICCs, 0.608-0.958), USP CCT readings were thicker (mean difference, up to 15.2 microm; P<0.05), and USP PCT readings were thinner (P<0.05). Orbscan and Pentacam average maps allowed comprehensive interpretation of differences between populations according to the magnitude, distribution, and statistical significance, minimizing the risk of giving excessive weight to few data measured at specific locations on the cornea. Both methodologies showed that Orbscan and

  12. Modelling Polymer Deformation and Welding Behaviour during 3D Printing

    NASA Astrophysics Data System (ADS)

    McIlroy, Claire; Olmsted, Peter

    2016-11-01

    3D printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The most common method, fused deposition modelling, involves melting a thermoplastic, followed by layer-by-layer extrusion of the material to fabricate a three-dimensional object. The key to the ensuring strength at the weld between these layers is successful inter-diffusion. However, as the printed layer cools towards the glass transition temperature, the time available for diffusion is limited. In addition, the extrusion process significantly deforms the polymer micro-structure prior to welding and consequently affects how the polymers "re-entangle" across the weld. We have developed a simple model of the non-isothermal printing process to explore the effects that typical printing conditions and amorphous polymer rheology have on the ultimate weld structure. In particular, we incorporate both the stretch and orientation of the polymer using the Rolie-Poly constitutive equation to examine how the melt flows through the nozzle and is deposited onto the build plate. We then address how this deformation relaxes and contributes to the thickness and structure of the weld. National Institute for Standards and Technology (NIST) and Georgetown University.

  13. Real-time acquisition of transendothelial electrical resistance in an all-human, in vitro, 3-dimensional, blood-brain barrier model exemplifies tight-junction integrity.

    PubMed

    Maherally, Zaynah; Fillmore, Helen L; Tan, Sim Ling; Tan, Suk Fei; Jassam, Samah A; Quack, Friederike I; Hatherell, Kathryn E; Pilkington, Geoffrey J

    2017-09-07

    The blood-brain barrier (BBB) consists of endothelial cells, astrocytes, and pericytes embedded in basal lamina (BL). Most in vitro models use nonhuman, monolayer cultures for therapeutic-delivery studies, relying on transendothelial electrical resistance (TEER) measurements without other tight-junction (TJ) formation parameters. We aimed to develop reliable, reproducible, in vitro 3-dimensional (3D) models incorporating relevant human, in vivo cell types and BL proteins. The 3D BBB models were constructed with human brain endothelial cells, human astrocytes, and human brain pericytes in mono-, co-, and tricultures. TEER was measured in 3D models using a volt/ohmmeter and cellZscope. Influence of BL proteins-laminin, fibronectin, collagen type IV, agrin, and perlecan-on adhesion and TEER was assessed using an electric cell-substrate impedance-sensing system. TJ protein expression was assessed by Western blotting (WB) and immunocytochemistry (ICC). Perlecan (10 µg/ml) evoked unreportedly high, in vitro TEER values (1200 Ω) and the strongest adhesion. Coculturing endothelial cells with astrocytes yielded the greatest resistance over time. ICC and WB results correlated with resistance levels, with evidence of prominent occludin expression in cocultures. BL proteins exerted differential effects on TEER, whereas astrocytes in contact yielded higher TEER values and TJ expression.-Maherally, Z., Fillmore, H. L., Tan, S. L., Tan, S. F., Jassam, S. A., Quack, F. I., Hatherell, K. E., Pilkington, G. J. Real-time acquisition of transendothelial electrical resistance in an all-human, in vitro, 3-dimensional, blood-brain barrier model exemplifies tight-junction integrity. © FASEB.

  14. Analytical modeling of printed metasurface cavities for computational imaging

    NASA Astrophysics Data System (ADS)

    F. Imani, Mohammadreza; Sleasman, Timothy; Gollub, Jonah N.; Smith, David R.

    2016-10-01

    We derive simple analytical expressions to model the electromagnetic response of an electrically large printed cavity. The analytical model is then used to develop printed cavities for microwave imaging purposes. The proposed cavity is excited by a cylindrical source and has boundaries formed by subwavelength metallic cylinders (vias) placed at subwavelength distances apart. Given their small size, the electric currents induced on the vias are assumed to have no angular dependence. Applying this approximation simplifies the electromagnetic problem to a matrix equation which can be solved to directly compute the electric current induced on each via. Once the induced currents are known, the electromagnetic field inside the cavity can be computed for every location. We verify the analytical model by comparing its prediction to full-wave simulations. To utilize this cavity in imaging settings, we perforate one side of the printed cavity with radiative slots such that they act as the physical layer of a computational imaging system. An analytical approximation for the slots is also developed, enabling us to obtain estimates of the cavity performance in imaging scenarios. This ability allows us to make informed decisions on the design of the printed metasurface cavity. The utility of the proposed model is further highlighted by demonstrating high-quality experimental imaging; performance metrics, which are consistent between theory and experiment, are also estimated.

  15. 3-dimensional fabrication of soft energy harvesters

    NASA Astrophysics Data System (ADS)

    McKay, Thomas; Walters, Peter; Rossiter, Jonathan; O'Brien, Benjamin; Anderson, Iain

    2013-04-01

    Dielectric elastomer generators (DEG) provide an opportunity to harvest energy from low frequency and aperiodic sources. Because DEG are soft, deformable, high energy density generators, they can be coupled to complex structures such as the human body to harvest excess mechanical energy. However, DEG are typically constrained by a rigid frame and manufactured in a simple planar structure. This planar arrangement is unlikely to be optimal for harvesting from compliant and/or complex structures. In this paper we present a soft generator which is fabricated into a 3 Dimensional geometry. This capability will enable the 3-dimensional structure of a dielectric elastomer to be customised to the energy source, allowing efficient and/or non-invasive coupling. This paper demonstrates our first 3 dimensional generator which includes a diaphragm with a soft elastomer frame. When the generator was connected to a self-priming circuit and cyclically inflated, energy was accumulated in the system, demonstrated by an increased voltage. Our 3D generator promises a bright future for dielectric elastomers that will be customised for integration with complex and soft structures. In addition to customisable geometries, the 3D printing process may lend itself to fabricating large arrays of small generator units and for fabricating truly soft generators with excellent impedance matching to biological tissue. Thus comfortable, wearable energy harvesters are one step closer to reality.

  16. 3DHYDROGEOCHEM: A 3-DIMENSIONAL MODEL OF DENSITY-DEPENDENT SUBSURFACE FLOW AND THERMAL MULTISPECIES-MULTICOMPONENT HYDROGEOCHEMICAL TRANSPORT

    EPA Science Inventory

    This report presents a three-dimensional finite-element numerical model designed to simulate chemical transport in subsurface systems with temperature effect taken into account. The three-dimensional model is developed to provide (1) a tool of application, with which one is able...

  17. 3DHYDROGEOCHEM: A 3-DIMENSIONAL MODEL OF DENSITY-DEPENDENT SUBSURFACE FLOW AND THERMAL MULTISPECIES-MULTICOMPONENT HYDROGEOCHEMICAL TRANSPORT

    EPA Science Inventory

    This report presents a three-dimensional finite-element numerical model designed to simulate chemical transport in subsurface systems with temperature effect taken into account. The three-dimensional model is developed to provide (1) a tool of application, with which one is able...

  18. User's manual for master: Modeling of aerodynamic surfaces by 3-dimensional explicit representation. [input to three dimensional computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Gibson, S. G.

    1983-01-01

    A system of computer programs was developed to model general three dimensional surfaces. Surfaces are modeled as sets of parametric bicubic patches. There are also capabilities to transform coordinates, to compute mesh/surface intersection normals, and to format input data for a transonic potential flow analysis. A graphical display of surface models and intersection normals is available. There are additional capabilities to regulate point spacing on input curves and to compute surface/surface intersection curves. Input and output data formats are described; detailed suggestions are given for user input. Instructions for execution are given, and examples are shown.

  19. The use of TOUGH2 for the LBL/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada

    SciTech Connect

    Bodvarsson, G.; Chen, G.; Haukwa, C.

    1995-03-01

    The three-dimensional site-scale numerical model of the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km{sup 2} and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge Fault) and perhaps to the north by an unconfirmed fault (Yucca Wash Fault). The model consists of about 5,000 grid blocks (elements) with nearly 20,000 connections between them the grid was designed to represent the most prevalent geological and hydro-geological features of the site including major faults, and layering and bedding of the hydro-geological units. Further information about the three-dimensional site-scale model is given by Wittwer et al. and Bodvarsson et al.

  20. Next Generation, Waveform Based 3-Dimensional Models & Metrics to Improve Nuclear Explosion Monitoring in the Middle East

    DTIC Science & Technology

    2012-04-20

    Indian tectonic plates . Without knowing the true lateral changes in anisotropy and including large continental provinces within the model it is...between recordings of seismic waves traversing the region from Tibet to the Red Sea compared to synthetics from the current iteration model is the...also significantly increase anomaly strength while sharpening the anomaly edges to create stronger and more pronounced tectonic structures. The

  1. Research on dynamic model of printed circuit board based on finite element method

    NASA Astrophysics Data System (ADS)

    Wei, Hui; Xu, Liangjun

    2017-08-01

    The vibration characteristics of printed circuit boards are related to the reliability of electronic components installed on their surface. Finite element software is a powerful tool to analyze the vibration characteristics of printed circuit boards, and the correct establishment of finite element model is very important. In this paper, the dynamic model of anisotropic printed circuit board is established by analyzing the material properties of printed circuit board. The influence of boundary condition and lumped mass on the vibration characteristics of printed circuit board is analyzed. In order to establish a more realistic printed circuit The finite element model of the plate provides the necessary basis.

  2. Facilitating surgeon understanding of complex anatomy using a three-dimensional printed model.

    PubMed

    Cromeens, Barrett P; Ray, William C; Hoehne, Brad; Abayneh, Fikir; Adler, Brent; Besner, Gail E

    2017-08-01

    3-dimensional prints (3DP) anecdotally facilitate surgeon understanding of anatomy and decision-making. However, the actual benefit to surgeons or patients has not been quantified. This study investigates how surgeon understanding of complex anatomy is altered by a 3DP compared to computed tomography (CT) scan or CT + digital reconstruction (CT + DR). Key anatomic features were segmented from a CT-abdomen/pelvis of pygopagus twins to build a DR and printed in color on a 3D printer. Pediatric surgery trainees and attendings (n = 21) were tested regarding anatomy identification and their understanding of point-to-point distances, scale, and shape. There was no difference between media regarding point-to-point distances. The 3DP led to an increased number of correct answers for questions of scale and shape compared to CT (P < 0.05). CT + DR performance was intermediate but not statistically different from 3DP or CT. Identification of anatomy was inconsistent between media; however, answers were significantly closer to correct when using the 3DP. Participants completed the test faster with the 3DP (6.6 ± 0.5 min) (P < 0.05) than with CT (18.9 ± 2.5 min) or CT + 3DR (14.9 ± 1.5 min). Although point-to-point measurements were not different, 3DP increased the understanding of shape, scale, and anatomy. It enabled understanding significantly faster than other media. In difficult surgical cases with complex anatomy and a need for efficient multidisciplinary coordination, 3D printed models should be considered for surgical planning. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Modified flapless dental implant surgery for planning treatment in a maxilla including sinus lift augmentation through use of virtual surgical planning and a 3-dimensional model.

    PubMed

    Nikzad, Sakineh; Azari, Abbas; Ghassemzadeh, Amanollah

    2010-09-01

    The concept of "prosthetic-driven implantology" may be considered a turning point in the history of modern dental implantology. On the basis of this sophisticated approach, the available bone and the optimal prosthetic position of the future restoration are checked before surgical intervention. However, the major drawback of today's prosthodontic discipline is that it is inherently 2-dimensional in nature, which may prevent the appropriate treatment; this problem can be overcome by the 3-dimensional capability of a computer-assisted approach when performed judiciously. It was proposed that this technique has the potential to provide a high level of safety and accuracy in comparison to traditional surgical procedures. Using a novel approach, we performed modified flapless implant surgery accompanied by a simultaneous sinus-lifting procedure. The technique used a 3-dimensional life-sized computer-aided design/computer-aided manufacturing (CAD/CAM) model prepared from the computed tomography images for prosthetic/surgical diagnosis and treatment planning. The procedure of implant planning, model surgery, and sinus floor augmentation in this sophisticated flapless surgical approach has the potential to provide substantial benefits for both patients and practitioners. The versatility of the described technique not only allows more accurate implementation of the treatment plan to the patient's mouth but also may offer many additional significant benefits, including the use of custom surgical guides, life-sized bone model manipulation, and surgical rehearsal, all of which are very difficult to achieve with current traditional procedures. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  4. A computational model for doctoring fluid films in gravure printing

    SciTech Connect

    Hariprasad, Daniel S.; Grau, Gerd; Schunk, P. Randall; Tjiptowidjojo, Kristianto

    2016-04-07

    The wiping, or doctoring, process in gravure printing presents a fundamental barrier to resolving the micron-sized features desired in printed electronics applications. This barrier starts with the residual fluid film left behind after wiping, and its importance grows as feature sizes are reduced, especially as the feature size approaches the thickness of the residual fluid film. In this work, various mechanical complexities are considered in a computational model developed to predict the residual fluid film thickness. Lubrication models alone are inadequate, and deformation of the doctor blade body together with elastohydrodynamic lubrication must be considered to make the model predictive of experimental trends. Moreover, model results demonstrate that the particular form of the wetted region of the blade has a significant impact on the model's ability to reproduce experimental measurements.

  5. A computational model for doctoring fluid films in gravure printing

    NASA Astrophysics Data System (ADS)

    Hariprasad, Daniel S.; Grau, Gerd; Schunk, P. Randall; Tjiptowidjojo, Kristianto

    2016-04-01

    The wiping, or doctoring, process in gravure printing presents a fundamental barrier to resolving the micron-sized features desired in printed electronics applications. This barrier starts with the residual fluid film left behind after wiping, and its importance grows as feature sizes are reduced, especially as the feature size approaches the thickness of the residual fluid film. In this work, various mechanical complexities are considered in a computational model developed to predict the residual fluid film thickness. Lubrication models alone are inadequate, and deformation of the doctor blade body together with elastohydrodynamic lubrication must be considered to make the model predictive of experimental trends. Moreover, model results demonstrate that the particular form of the wetted region of the blade has a significant impact on the model's ability to reproduce experimental measurements.

  6. Direct measurement of the 3-dimensional DNA lesion distribution induced by energetic charged particles in a mouse model tissue

    PubMed Central

    Mirsch, Johanna; Tommasino, Francesco; Frohns, Antonia; Conrad, Sandro; Durante, Marco; Scholz, Michael; Friedrich, Thomas; Löbrich, Markus

    2015-01-01

    Charged particles are increasingly used in cancer radiotherapy and contribute significantly to the natural radiation risk. The difference in the biological effects of high-energy charged particles compared with X-rays or γ-rays is determined largely by the spatial distribution of their energy deposition events. Part of the energy is deposited in a densely ionizing manner in the inner part of the track, with the remainder spread out more sparsely over the outer track region. Our knowledge about the dose distribution is derived solely from modeling approaches and physical measurements in inorganic material. Here we exploited the exceptional sensitivity of γH2AX foci technology and quantified the spatial distribution of DNA lesions induced by charged particles in a mouse model tissue. We observed that charged particles damage tissue nonhomogenously, with single cells receiving high doses and many other cells exposed to isolated damage resulting from high-energy secondary electrons. Using calibration experiments, we transformed the 3D lesion distribution into a dose distribution and compared it with predictions from modeling approaches. We obtained a radial dose distribution with sub-micrometer resolution that decreased with increasing distance to the particle path following a 1/r2 dependency. The analysis further revealed the existence of a background dose at larger distances from the particle path arising from overlapping dose deposition events from independent particles. Our study provides, to our knowledge, the first quantification of the spatial dose distribution of charged particles in biologically relevant material, and will serve as a benchmark for biophysical models that predict the biological effects of these particles. PMID:26392532

  7. New 3-dimensional CFD modeling of CO2 and H2S simultaneous stripping from water within PVDF hollow fiber membrane contactor

    NASA Astrophysics Data System (ADS)

    Bahlake, Ahmad; Farivar, Foad; Dabir, Bahram

    2016-07-01

    In this paper a 3-dimensional modeling of simultaneous stripping of carbon dioxide (CO2) and hydrogen sulfide (H2S) from water using hollow fiber membrane made of polyvinylidene fluoride is developed. The water, containing CO2 and H2S enters to the membrane as feed. At the same time, pure nitrogen flow in the shell side of a shell and tube hollow fiber as the solvent. In the previous methods of modeling hollow fiber membranes just one of the membranes was modeled and the results expand to whole shell and tube system. In this research the whole hollow fiber shell and tube module is modeled to reduce the errors. Simulation results showed that increasing the velocity of solvent flow and decreasing the velocity of the feed are leads to increase in the system yield. However the effect of the feed velocity on the process is likely more than the influence of changing the velocity of the gaseous solvent. In addition H2S stripping has higher yield in comparison with CO2 stripping. This model is compared to the previous modeling methods and shows that the new model is more accurate. Finally, the effect of feed temperature is studied using response surface method and the operating conditions of feed temperature, feed velocity, and solvent velocity is optimized according to synergistic effects. Simulation results show that, in the optimum operating conditions the removal percentage of H2S and CO2 are 27 and 21 % respectively.

  8. Knee rotation influences the femoral tunnel angle measurement after anterior cruciate ligament reconstruction: a 3-dimensional computed tomography model study.

    PubMed

    Tang, Jing; Thorhauer, Eric; Marsh, Chelsea; Fu, Freddie H; Tashman, Scott

    2014-07-01

    Femoral tunnel angle (FTA) has been proposed as a metric for evaluating whether ACL reconstruction was performed anatomically. In clinic, radiographic images are typically acquired with an uncertain amount of internal/external knee rotation. The extent to which knee rotation will influence FTA measurement is unclear. Furthermore, differences in FTA measurement between the two common positions (0° and 45° knee flexion) have not been established. The purpose of this study was to investigate the influence of knee rotation on FTA measurement after ACL reconstruction. Knee CT data from 16 subjects were segmented to produce 3D bone models. Central axes of tunnels were identified. The 0° and 45° flexion angles were simulated. Knee internal/external rotations were simulated in a range of ± 20°. FTA was defined as the angle between the tunnel axis and femoral shaft axis, orthogonally projected into the coronal plane. Femoral tunnel angle was positively/negatively correlated with knee rotation angle at 0°/45° knee flexion. At 0° knee flexion, FTA for anterio-medial (AM) tunnels was significantly decreased at 20° of external knee rotation. At 45° knee flexion, more than 16° external or 19° internal rotation significantly altered FTA measurements for single-bundle tunnels; smaller rotations (± 9° for AM, ± 5° for PL) created significant errors in FTA measurements after double-bundle reconstruction. Femoral tunnel angle measurements were correlated with knee rotation. Relatively small imaging malalignment introduced significant errors with knee flexed 45°. This study supports using the 0° flexion position for knee radiographs to reduce errors in FTA measurement due to knee internal/external rotation.

  9. Estimating neugebauer primaries for multi-channel spectral printing modeling

    NASA Astrophysics Data System (ADS)

    Slavuj, Radovan; Coppel, Ludovic G.; Olen, Melissa; Hardeberg, Jon Yngve

    2014-02-01

    Multichannel printer modeling has been an active area of research in the field of spectral printing. The most commonly used models for characterization of such systems are the spectral Neugebauer (SN) and its extensions. This work addresses issues that can arise during calibration and testing of the SN model when modelling a 7-colorant printer. Since most substrates are limited in their capacity to take in large amount of ink, it is not always possible to print all colorant combinations necessary to determine the Neugebauer primaries (NP). A common solution is to estimate the nonprintable Neugebauer primaries from the single colorant primaries using the Kubelka-Munk (KM) optical model. In this work we test whether a better estimate can be obtained using general radiative transfer theory, which better represents the angular variation of the reflectance from highly absorbing media, and takes surface scattering into account. For this purpose we use the DORT2002 model. We conclude DORT2002 does not offer significant improvements over KM in the estimation of the NPs, but a significant improvement is obtained when using a simple surface scattering model. When the estimated primaries are used as inputs to the SN model instead of measured ones, it is found the SN model performs the same or better in terms of color difference and spectral error. If the mixed measured and estimated primaries are used as inputs to the SN model, it performs better than using either measured or estimated.

  10. Accuracy of open-source software segmentation and paper-based printed three-dimensional models.

    PubMed

    Szymor, Piotr; Kozakiewicz, Marcin; Olszewski, Raphael

    2016-02-01

    .43 ± 19.39; however, deviation in some of the generated points could not be calculated, and those points were excluded from further calculations. From 94% to 99% of the measured absolute deviations were <1 mm. The mean absolute deviation between the skull and virtual model was 0.15 ± 0.11 mm, between the virtual and printed models was 0.15 ± 0.12 mm, and between the skull and printed models was 0.24 ± 0.21 mm. Using the optical scanner and specialized inspection software for measurements of accuracy of the created parts is recommended, as it allows one not only to measure 2-dimensional distances between anatomical points but also to perform more clinically suitable comparisons of whole surfaces. However, it requires specialized software and a very accurate scanner in order to be useful. Threshold-based, manually corrected segmentation of orbital walls performed with 3D Slicer software is accurate enough to be used for creating a virtual model of the orbit. The accuracy of the paper-based Mcor Matrix 300 3D printer is comparable to those of other commonly used 3-dimensional printers and allows one to create precise anatomical models for clinical use. The method of dividing the model into smaller parts and sticking them together seems to be quite accurate, although we recommend it only for creating small, solid models with as few parts as possible to minimize shift associated with gluing. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  11. 3D Printing of Biomolecular Models for Research and Pedagogy

    PubMed Central

    Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel

    2017-01-01

    The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology. PMID:28362403

  12. Testing Mercury Porosimetry with 3D Printed Porosity Models

    NASA Astrophysics Data System (ADS)

    Hasiuk, F.; Ewing, R. P.; Hu, Q.

    2014-12-01

    Mercury intrusion porosimetry is one of the most widely used techniques to study the porous nature of a geological and man-made materials. In the geosciences, it is commonly used to describe petroleum reservoir and seal rocks as well as to grade aggregates for the design of asphalt and portland cement concretes. It's wide utility stems from its ability to characterize a wide range of pore throat sizes (from nanometers to around a millimeter). The fundamental physical model underlying mercury intrusion porosimetry, the Washburn Equation, is based on the assumption that rock porosity can be described as a bundle of cylindrical tubes. 3D printing technology, also known as rapid prototyping, allows the construction of intricate and accurate models, exactly what is required to build models of rock porosity. We evaluate the applicability of the Washburn Equation by comparing properties (like porosity, pore and pore throat size distribution, and surface area) computed on digital porosity models (built from CT data, CAD designs, or periodic geometries) to properties measured via mercury intrusion porosimetry on 3D printed versions of the same digital porosity models.

  13. 3D Printing of Biomolecular Models for Research and Pedagogy.

    PubMed

    Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel

    2017-03-13

    The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.

  14. Four-Dimensional Phase Contrast Magnetic Resonance Imaging Protocol Optimization Using Patient-Specific 3-Dimensional Printed Replicas for In Vivo Imaging Before and After Flow Diverter Placement.

    PubMed

    Karmonik, Christof; Anderson, Jeff R; Elias, Saba; Klucznik, Richard; Diaz, Orlando; Zhang, Yi Jonathan; Grossman, Robert G; Britz, Gavin W

    2017-09-01

    Hemodynamics in cerebral aneurysms are currently investigated toward clinical efficacy using nonstandardized computational simulation techniques. At the same time, flow patterns and velocities are accessible by 4-dimensional phase contrast magnetic resonance imaging (4D pcMRI). Complexity of protocol design and imaging duration has limited the use of this technique in clinical imaging. A new approach is presented to overcome these limitations. Three-dimensional (3D) replicas of 2 cerebral aneurysms were fabricated by fused deposition prototyping (3D printing) and imaged using 4D pcMRI while connected to a magnetic resonance imaging-compatible continuous flow loop. Acquisition parameters were optimized with imaging times not to exceed 10 minutes. Six patients harboring cerebral aneurysms with sizes ranging from 4.7 to 13.8 mm were imaged with the optimized 4D pcMRI protocol. After treatment with the pipeline embolization device (PED), 4D pcMRI examinations were repeated in 3 patients. In all cases, major flow patterns were visualized well; smaller aneurysms posed a challenge because of limited spatial resolution, whereas larger aneurysms contained regions of low velocity resulting in limited contrast in the flow-sensitive images. After PED placement, ordered aneurysmal flow was disrupted and intra-aneurysmal velocity was reduced on average by 24.5% (range, 12.9-31.5%). Exploratory statistical analysis yielded a positive significant correlation (P < 0.01) between changes in inflow velocity and posttreatment intra-aneurysmal flow velocity. 4D pcMRI flow imaging in cerebral aneurysms within a time frame suitable for clinical imaging applications is feasible with optimized acquisition parameters, thereby enabling quantification of intra-aneurysmal flow changes after flow diverter device treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. A Validation Study of a Novel 3-Dimensional MRI Modeling Technique to Identify the Anatomic Insertions of the Anterior Cruciate Ligament

    PubMed Central

    Hui, Catherine; Pi, Yeli; Swami, Vimarsha; Mabee, Myles; Jaremko, Jacob L.

    2016-01-01

    Background: Anatomic single bundle anterior cruciate ligament (ACL) reconstruction is the current gold standard in ACL reconstructive surgery. However, placement of femoral and tibial tunnels at the anatomic center of the ACL insertion sites can be difficult intraoperatively. We developed a “virtual arthroscopy” program that allows users to identify ACL insertions on preoperative knee magnetic resonance images (MRIs) and generates a 3-dimensional (3D) bone model that matches the arthroscopic view to help guide intraoperative tunnel placement. Purpose: To test the validity of the ACL insertion sites identified using our 3D modeling program and to determine the accuracy of arthroscopic ACL reconstruction guided by our “virtual arthroscopic” model. Study Design: Descriptive laboratory study. Methods: Sixteen cadaveric knees were prescanned using routine MRI sequences. A trained, blinded observer then identified the center of the ACL insertions using our program. Eight knees were dissected, and the centers of the ACL footprints were marked with a screw. In the remaining 8 knees, arthroscopic ACL tunnels were drilled into the center of the ACL footprints based on landmarks identified using our virtual arthroscopic model. Postprocedural MRI was performed on all 16 knees. The 3D distance between pre- and postoperative 3D centers of the ACL were calculated by 2 trained, blinded observers and a musculoskeletal radiologist. Results: With 2 outliers removed, the postoperative femoral and tibial tunnel placements in the open specimens differed by 2.5 ± 0.9 mm and 2.9 ± 0.7 mm from preoperative centers identified on MRI. Postoperative femoral and tibial tunnel centers in the arthroscopic specimens differed by 3.2 ± 0.9 mm and 2.9 ± 0.7 mm, respectively. Conclusion: Our results show that MRI-based 3D localization of the ACL and our virtual arthroscopic modeling program is feasible and does not show a statistically significant difference to an open arthrotomy approach

  16. Rigorous 3-dimensional spectral data activity relationship approach modeling strategy for ToxCast estrogen receptor data classification, validation, and feature extraction.

    PubMed

    Slavov, Svetoslav H; Beger, Richard D

    2017-03-01

    The estrogenic potential (expressed as a score composite of 18 high throughput screening bioassays) of 1528 compounds from the ToxCast database was modeled by a 3-dimensional spectral data activity relationship approach (3D-SDAR). Due to a lack of (17) O nuclear magnetic resonance (NMR) simulation software, the most informative carbon-carbon 3D-SDAR fingerprints were augmented with indicator variables representing oxygen atoms from carbonyl and carboxamide, ester, sulfonyl, nitro, aliphatic hydroxyl, and phenolic hydroxyl groups. To evaluate the true predictive performance of the authors' model the United States Environmental Protection Agency provided them with a blind test set consisting of 2008 compounds. Of these, 543 had available literature data-their binding affinity served to estimate the external classification accuracy of the developed model: predictive accuracy of 0.62, sensitivity of 0.71, and specificity of 0.53 were obtained. Compared with alternative modeling techniques, the authors' model displayed very little reduction in performance between the modeling and the prediction set. A 3D-SDAR mapping technique allowed identification of structural features essential for estrogenicity: 1) the presence of a phenolic OH group or cyclohexenone, 2) a second aromatic or phenolic ring at a distance of 6 Å to 8 Å from the oxygen of the first phenol ring, 3) the presence of a methyl group approximately 6 Å away from the centroid of a phenol ring, and 4) a carbonyl group in close proximity (∼4 Å measured to the centroid) to 1 of the phenol rings. Environ Toxicol Chem 2017;36:823-830. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  17. Design, modeling and testing of integrated ring extractor for high resolution electrohydrodynamic (EHD) 3D printing

    NASA Astrophysics Data System (ADS)

    Han, Yiwei; Dong, Jingyan

    2017-03-01

    This paper presents an integrated ring extractor design in electrohydrodynamic (EHD) printing, which can overcome the standoff height limitation in the EHD printing process, and improve printing capability for 3D structures. Standoff height in the EHD printing will affect printing processes and limit the height of the printed structure when the ground electrode is placed under the substrate. In this work, we designed and integrated a ring electrode with the printing nozzle to achieve a self-working printer head, which can start and maintain the printing process without the involvement of the substrate. We applied a FEA method to model the electric field potential distribution and strength to direct the ring extractor design, which provides a similar printing capability with the system using substrate as the ground electrode. We verified the ring electrode design by experiments, and those results from the experiments demonstrated a good match with results from the FEA simulation. We have characterized the printing processes using the integrated ring extractor, and successfully applied this newly designed ring extractor to print polycaprolactone (PCL) 3D structures.

  18. 3D Printed Models of Cleft Palate Pathology for Surgical Education.

    PubMed

    Lioufas, Peter A; Quayle, Michelle R; Leong, James C; McMenamin, Paul G

    2016-09-01

    To explore the potential viability and limitations of 3D printed models of children with cleft palate deformity. The advantages of 3D printed replicas of normal anatomical specimens have previously been described. The creation of 3D prints displaying patient-specific anatomical pathology for surgical planning and interventions is an emerging field. Here we explored the possibility of taking rare pediatric radiographic data sets to create 3D prints for surgical education. Magnetic resonance imaging data of 2 children (8 and 14 months) were segmented, colored, and anonymized, and stereolothographic files were prepared for 3D printing on either multicolor plastic or powder 3D printers and multimaterial 3D printers. Two models were deemed of sufficient quality and anatomical accuracy to print unamended. One data set was further manipulated digitally to artificially extend the length of the cleft. Thus, 3 models were printed: 1 incomplete soft-palate deformity, 1 incomplete anterior palate deformity, and 1 complete cleft palate. All had cleft lip deformity. The single-material 3D prints are of sufficient quality to accurately identify the nature and extent of the deformities. Multimaterial prints were subsequently created, which could be valuable in surgical training. Improvements in the quality and resolution of radiographic imaging combined with the advent of multicolor multiproperty printer technology will make it feasible in the near future to print 3D replicas in materials that mimic the mechanical properties and color of live human tissue making them potentially suitable for surgical training.

  19. Utilisation of three-dimensional printed heart models for operative planning of complex congenital heart defects.

    PubMed

    Olejník, Peter; Nosal, Matej; Havran, Tomas; Furdova, Adriana; Cizmar, Maros; Slabej, Michal; Thurzo, Andrej; Vitovic, Pavol; Klvac, Martin; Acel, Tibor; Masura, Jozef

    2017-01-01

    To evaluate the accuracy of the three-dimensional (3D) printing of cardiovascular structures. To explore whether utilisation of 3D printed heart replicas can improve surgical and catheter interventional planning in patients with complex congenital heart defects. Between December 2014 and November 2015 we fabricated eight cardiovascular models based on computed tomography data in patients with complex spatial anatomical relationships of cardiovascular structures. A Bland-Altman analysis was used to assess the accuracy of 3D printing by comparing dimension measurements at analogous anatomical locations between the printed models and digital imagery data, as well as between printed models and in vivo surgical findings. The contribution of 3D printed heart models for perioperative planning improvement was evaluated in the four most representative patients. Bland-Altman analysis confirmed the high accuracy of 3D cardiovascular printing. Each printed model offered an improved spatial anatomical orientation of cardiovascular structures. Current 3D printers can produce authentic copies of patients` cardiovascular systems from computed tomography data. The use of 3D printed models can facilitate surgical or catheter interventional procedures in patients with complex congenital heart defects due to better preoperative planning and intraoperative orientation.

  20. Hydroelectric structures studies using 3-dimensional methods

    SciTech Connect

    Harrell, T.R.; Jones, G.V.; Toner, C.K. )

    1989-01-01

    Deterioration and degradation of aged, hydroelectric project structures can significantly affect the operation and safety of a project. In many cases, hydroelectric headworks (in particular) have complicated geometrical configurations, loading patterns and hence, stress conditions. An accurate study of such structures can be performed using 3-dimensional computer models. 3-D computer models can be used for both stability evaluation and for finite element stress analysis. Computer aided engineering processes facilitate the use of 3-D methods in both pre-processing and post-processing of data. Two actual project examples are used to emphasize the authors' points.

  1. A thermodynamic and mechanical model for formation of the Solar System via 3-dimensional collapse of the dusty pre-solar nebula

    NASA Astrophysics Data System (ADS)

    Hofmeister, Anne M.; Criss, Robert E.

    2012-03-01

    The fundamental and shared rotational characteristics of the Solar System (nearly circular, co-planar orbits and mostly upright axial spins of the planets) record conditions of origin, yet are not explained by prevailing 2-dimensional disk models. Current planetary spin and orbital rotational energies (R.E.) each nearly equal and linearly depend on gravitational self-potential of formation (Ug), revealing mechanical energy conservation. We derive -ΔUg≅Δ.R.E. and stability criteria from thermodynamic principles, and parlay these relationships into a detailed model of simultaneous accretion of the protoSun and planets from the dust-bearing 3-d pre-solar nebula (PSN). Gravitational heating is insignificant because Ug is negative, the 2nd law of thermodynamics must be fulfilled, and ideal gas conditions pertain to the rarified PSN until the objects were nearly fully formed. Combined conservation of angular momentum and mechanical energy during 3-dimensional collapse of spheroidal dust shells in a contracting nebula provides ΔR.E.≅R.E. for the central body, whereas for formation of orbiting bodies, ΔR.E.≅R.E.f(1-If/Ii), where I is the moment of inertia. Orbital data for the inner planets follow 0.04×R.E.f≅-Ug which confirms conservation of angular momentum. Significant loss of spin, attributed to viscous dissipation during differential rotation, masks the initial spin of the un-ignited protoSun predicted by R.E.=-Ug. Heat production occurs after nearly final sizes are reached via mechanisms such as shear during differential rotation and radioactivity. We focus on the dilute stage, showing that the PSN was compositionally graded due to light molecules diffusing preferentially, providing the observed planetary chemistry, and set limits on PSN mass, density, and temperature. From measured planetary masses and orbital characteristics, accounting for dissipation of spin, we deduce mechanisms and the sequence of converting a 3-d dusty cloud to the present 2-d

  2. Three-dimensional printing of Hela cells for cervical tumor model in vitro.

    PubMed

    Zhao, Yu; Yao, Rui; Ouyang, Liliang; Ding, Hongxu; Zhang, Ting; Zhang, Kaitai; Cheng, Shujun; Sun, Wei

    2014-09-01

    Advances in three-dimensional (3D) printing have enabled the direct assembly of cells and extracellular matrix materials to form in vitro cellular models for 3D biology, the study of disease pathogenesis and new drug discovery. In this study, we report a method of 3D printing for Hela cells and gelatin/alginate/fibrinogen hydrogels to construct in vitro cervical tumor models. Cell proliferation, matrix metalloproteinase (MMP) protein expression and chemoresistance were measured in the printed 3D cervical tumor models and compared with conventional 2D planar culture models. Over 90% cell viability was observed using the defined printing process. Comparisons of 3D and 2D results revealed that Hela cells showed a higher proliferation rate in the printed 3D environment and tended to form cellular spheroids, but formed monolayer cell sheets in 2D culture. Hela cells in 3D printed models also showed higher MMP protein expression and higher chemoresistance than those in 2D culture. These new biological characteristics from the printed 3D tumor models in vitro as well as the novel 3D cell printing technology may help the evolution of 3D cancer study.

  3. A Pilot Study Assessing the Impact of 3-D Printed Models of Aortic Aneurysms on Management Decisions in EVAR Planning.

    PubMed

    Tam, Matthew D; Latham, Tom R; Lewis, Mark; Khanna, Kunal; Zaman, Ali; Parker, Mike; Grunwald, Iris Q

    2016-01-01

    Endovascular repair of aortic aneurysms with difficult anatomy is challenging. There is no consensus for planning such procedures. Six cases of aortic aneurysms with challenging anatomical features, such as short, angulated, and conical necks and tortuous iliacs were harvested. The computed tomography (CT) scans were anonymized. Lifesize 3-dimensional (3-D) printed models were created of the lumen. Endovascular operators were asked to review the CT angiography (CTA), make a management plan, and give an indication of their confidence. They were then presented with the equivalent model and asked to review their decision. Their attitudes to such models were briefly surveyed. A total of 28 endovascular operators reviewed 144 cases. After review of the physical model, the management plan changed in 29 (20.1%) of 144 cases. Initial plan after CTA review was endovascular 73.6%, open repair 22.9%, and second opinion 3.5%. After model review, this became endovascular 67.4%, open repair 19.4%, and second opinion 4.8%. Although the general trend was toward more open procedures, off-label techniques reduced from 19.4% to 15.2% following model review. When the management plan did not change, level of confidence did increase in 37 (43.5%) of 85 cases. The majority of operators stated that they would find models useful for planning in some procedures. For 1 case, the change in the percentage of participants being sure in the management plan was statistically significant (P = .031). The 3-D printed models may be potentially useful in planning cases with EVAR. It is a paradigm that warrants further investigation. © The Author(s) 2016.

  4. 3D Printing of Molecular Potential Energy Surface Models

    ERIC Educational Resources Information Center

    Lolur, Phalgun; Dawes, Richard

    2014-01-01

    Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…

  5. 3D Printing of Molecular Potential Energy Surface Models

    ERIC Educational Resources Information Center

    Lolur, Phalgun; Dawes, Richard

    2014-01-01

    Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…

  6. Development of an Innovative 3D Printed Rigid Bronchoscopy Training Model.

    PubMed

    Al-Ramahi, Jehad; Luo, Huiping; Fang, Rui; Chou, Adriana; Jiang, Jack; Kille, Tony

    2016-12-01

    The objective of this study was to create a 3D printed airway model simulating the size and mechanical properties of various age groups for foreign body removal training. Three-dimensional printing technology was used to print the anatomically correct airway from rubber-like translucent material, simulating the mechanical properties of human airway tissue. The model's effectiveness in trainee education was evaluated by otolaryngology residents with varying levels of experience. As part of an Airway Emergencies course, a rigid bronchoscopy procedure was performed on the 3D printed model as well as a porcine model. The participants completed surveys comparing the validity of the 2 models and the effectiveness of the overall training experience. The 3D printed model, which is accurate in terms of anatomy and mechanical properties, was found to be comparable to a porcine model in regards to participant satisfaction as well as face validity. The 3D printed airway model is able to be accurately scaled to various sizes and simulate the mechanical properties of the desired age group. The 3D printed model provides an excellent alternative to animal models in terms of practicality, logistics of use, and anatomical accuracy. © The Author(s) 2016.

  7. 3D Modeling and Printing in History/Social Studies Classrooms: Initial Lessons and Insights

    ERIC Educational Resources Information Center

    Maloy, Robert; Trust, Torrey; Kommers, Suzan; Malinowski, Allison; LaRoche, Irene

    2017-01-01

    This exploratory study examines the use of 3D technology by teachers and students in four middle school history/social studies classrooms. As part of a university-developed 3D Printing 4 Teaching & Learning project, teachers integrated 3D modeling and printing into curriculum topics in world geography, U.S. history, and government/civics.…

  8. Virtual and Printed 3D Models for Teaching Crystal Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Casas, Lluís; Estop, Euge`nia

    2015-01-01

    Both, virtual and printed 3D crystal models can help students and teachers deal with chemical education topics such as symmetry and point groups. In the present paper, two freely downloadable tools (interactive PDF files and a mobile app) are presented as examples of the application of 3D design to study point-symmetry. The use of 3D printing to…

  9. Virtual and Printed 3D Models for Teaching Crystal Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Casas, Lluís; Estop, Euge`nia

    2015-01-01

    Both, virtual and printed 3D crystal models can help students and teachers deal with chemical education topics such as symmetry and point groups. In the present paper, two freely downloadable tools (interactive PDF files and a mobile app) are presented as examples of the application of 3D design to study point-symmetry. The use of 3D printing to…

  10. Using 3D printed models for planning and guidance during endovascular intervention: a technical advance

    PubMed Central

    Itagaki, Michael W.

    2015-01-01

    Three-dimensional (3D) printing applications in medicine have been limited due to high cost and technical difficulty of creating 3D printed objects. It is not known whether patient-specific, hollow, small-caliber vascular models can be manufactured with 3D printing, and used for small vessel endoluminal testing of devices. Manufacture of anatomically accurate, patient-specific, small-caliber arterial models was attempted using data from a patient’s CT scan, free open-source software, and low-cost Internet 3D printing services. Prior to endovascular treatment of a patient with multiple splenic artery aneurysms, a 3D printed model was used preoperatively to test catheter equipment and practice the procedure. A second model was used intraoperatively as a reference. Full-scale plastic models were successfully produced. Testing determined the optimal puncture site for catheter positioning. A guide catheter, base catheter, and microcatheter combination selected during testing was used intraoperatively with success, and the need for repeat angiograms to optimize image orientation was minimized. A difficult and unconventional procedure was successful in treating the aneurysms while preserving splenic function. We conclude that creation of small-caliber vascular models with 3D printing is possible. Free software and low-cost printing services make creation of these models affordable and practical. Models are useful in preoperative planning and intraoperative guidance. PMID:26027767

  11. Three-dimensional (3D) printed endovascular simulation models: a feasibility study

    PubMed Central

    Nesbitt, Craig; McCaslin, James; Bagnall, Alan; Davey, Philip; Bose, Pentop; Williams, Rob

    2017-01-01

    Background Three-dimensional (3D) printing is a manufacturing process in which an object is created by specialist printers designed to print in additive layers to create a 3D object. Whilst there are initial promising medical applications of 3D printing, a lack of evidence to support its use remains a barrier for larger scale adoption into clinical practice. Endovascular virtual reality (VR) simulation plays an important role in the safe training of future endovascular practitioners, but existing VR models have disadvantages including cost and accessibility which could be addressed with 3D printing. Methods This study sought to evaluate the feasibility of 3D printing an anatomically accurate human aorta for the purposes of endovascular training. Results A 3D printed model was successfully designed and printed and used for endovascular simulation. The stages of development and practical applications are described. Feedback from 96 physicians who answered a series of questions using a 5 point Likert scale is presented. Conclusions Initial data supports the value of 3D printed endovascular models although further educational validation is required. PMID:28251121

  12. Use of 3D Printed Models in Medical Education: A Randomized Control Trial Comparing 3D Prints versus Cadaveric Materials for Learning External Cardiac Anatomy

    ERIC Educational Resources Information Center

    Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J.; Adams, Justin W.; McMenamin, Paul G.

    2016-01-01

    Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized…

  13. Use of 3D Printed Models in Medical Education: A Randomized Control Trial Comparing 3D Prints versus Cadaveric Materials for Learning External Cardiac Anatomy

    ERIC Educational Resources Information Center

    Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J.; Adams, Justin W.; McMenamin, Paul G.

    2016-01-01

    Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized…

  14. 3-dimensional (3D) fabricated polymer based drug delivery systems.

    PubMed

    Moulton, Simon E; Wallace, Gordon G

    2014-11-10

    Drug delivery from 3-dimensional (3D) structures is a rapidly growing area of research. It is essential to achieve structures wherein drug stability is ensured, the drug loading capacity is appropriate and the desired controlled release profile can be attained. Attention must also be paid to the development of appropriate fabrication machinery that allows 3D drug delivery systems (DDS) to be produced in a simple, reliable and reproducible manner. The range of fabrication methods currently being used to form 3D DDSs include electrospinning (solution and melt), wet-spinning and printing (3-dimensional). The use of these techniques enables production of DDSs from the macro-scale down to the nano-scale. This article reviews progress in these fabrication techniques to form DDSs that possess desirable drug delivery kinetics for a wide range of applications.

  15. 3D Printed Models of Cleft Palate Pathology for Surgical Education

    PubMed Central

    Lioufas, Peter A.; Quayle, Michelle R.; Leong, James C.

    2016-01-01

    Objective: To explore the potential viability and limitations of 3D printed models of children with cleft palate deformity. Background: The advantages of 3D printed replicas of normal anatomical specimens have previously been described. The creation of 3D prints displaying patient-specific anatomical pathology for surgical planning and interventions is an emerging field. Here we explored the possibility of taking rare pediatric radiographic data sets to create 3D prints for surgical education. Methods: Magnetic resonance imaging data of 2 children (8 and 14 months) were segmented, colored, and anonymized, and stereolothographic files were prepared for 3D printing on either multicolor plastic or powder 3D printers and multimaterial 3D printers. Results: Two models were deemed of sufficient quality and anatomical accuracy to print unamended. One data set was further manipulated digitally to artificially extend the length of the cleft. Thus, 3 models were printed: 1 incomplete soft-palate deformity, 1 incomplete anterior palate deformity, and 1 complete cleft palate. All had cleft lip deformity. The single-material 3D prints are of sufficient quality to accurately identify the nature and extent of the deformities. Multimaterial prints were subsequently created, which could be valuable in surgical training. Conclusion: Improvements in the quality and resolution of radiographic imaging combined with the advent of multicolor multiproperty printer technology will make it feasible in the near future to print 3D replicas in materials that mimic the mechanical properties and color of live human tissue making them potentially suitable for surgical training. PMID:27757345

  16. Multimaterial polyacrylamide: fabrication with electrohydrodynamic jet printing, applications, and modeling.

    PubMed

    Poellmann, Michael J; Johnson, Amy J Wagoner

    2014-09-01

    Micropatterned, multimaterial hydrogels have a wide range of applications, including the study of microenvironmental factors on cell behavior, and complex materials that rapidly change shape in response to fluid composition. This paper presents a method to fabricate microscale polyacrylamide features embedded in a second hydrogel of a different composition. An electrohydrodynamic jet (e-jet) printer was used to pattern hemispherical droplets of polyacrylamide prepolymer on a passive substrate. After photopolymerization, the droplets were backfilled with a second polyacrylamide mixture, the second mixture was polymerized and the sample was peeled off the substrate. Fluorescent and confocal microscopy confirmed multimaterial patterning, while scanning probe microscopy revealed a patterned topography with printed spots forming shallow wells. Finite element modeling was used to understand the mechanics of the formation of the topographical features during backfill and subsequent polymerization. Finally, polyacrylamide containing acrylic acid was used to demonstrate two applications of the micropatterned hydrogels: stimuli-responsive materials and patterned substrates for cell culture. The e-jet fabrication technique described here is a highly flexible, high resolution method for creating multimaterial hydrogels.

  17. Plasticized protein for 3D printing by fused deposition modeling

    NASA Astrophysics Data System (ADS)

    Chaunier, Laurent; Leroy, Eric; Della Valle, Guy; Lourdin, Denis

    2016-10-01

    The developments of Additive Manufacturing (AM) by Fused Deposition Modeling (FDM) now target new 3D printable materials, leading to novel properties like those given by biopolymers such as proteins: degradability, biocompatibility and edibility. Plasticized materials from zein, a storage protein issued from corn, present interesting thermomechanical and rheological properties, possibly matching with AM-FDM specifications. Thus commercial zein plasticized with 20% glycerol has a glass transition temperature (Tg) at about 42°C, after storage at intermediate relative humidity (RH=59%). Its principal mechanical relaxation at Tα ≈ 50°C leads to a drop of the elastic modulus from about 1.1 GPa, at ambient temperature, to 0.6 MPa at Tα+100°C. These values are in the same range as values obtained in the case of standard polymers for AM-FDM processing, as PLA and ABS, although relaxation mechanisms are likely different in these materials. Such results lead to the setting up of zein-based compositions printable by AM-FDM and allow processing bioresorbable printed parts, with designed 3D geometry and structure.

  18. Characterisation of the n-colour printing process using the spot colour overprint model.

    PubMed

    Deshpande, Kiran; Green, Phil; Pointer, Michael R

    2014-12-29

    This paper is aimed at reproducing the solid spot colours using the n-colour separation. A simplified numerical method, called as the spot colour overprint (SCOP) model, was used for characterising the n-colour printing process. This model was originally developed for estimating the spot colour overprints. It was extended to be used as a generic forward characterisation model for the n-colour printing process. The inverse printer model based on the look-up table was implemented to obtain the colour separation for n-colour printing process. Finally the real-world spot colours were reproduced using 7-colour separation on lithographic offset printing process. The colours printed with 7 inks were compared against the original spot colours to evaluate the accuracy. The results show good accuracy with the mean CIEDE2000 value between the target colours and the printed colours of 2.06. The proposed method can be used successfully to reproduce the spot colours, which can potentially save significant time and cost in the printing and packaging industry.

  19. Dual-Extrusion 3D Printing of Anatomical Models for Education.

    PubMed

    Smith, Michelle L; Jones, James F X

    2017-09-14

    Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex(3D) flexible filament and polylactic acid (PLA) filament were extruded respectively via a single 0.4 mm nozzle using a Big Builder printer. For each filament, cubes (5 mm(3) ) were printed and analyzed for X, Y, and Z accuracy. The PLA printed cubes resulted in errors averaging just 1.2% across all directions but for FilaFlex(3D) printed cubes the errors were statistically significantly greater (average of 3.2%). As an exemplar, a focus was placed on the muscles, bones and cartilage of upper airway and neck. The resulting single prints combined flexible and hard structures. A single print model of the vocal cords was constructed which permitted movement of the arytenoids on the cricoid cartilage and served to illustrate the action of intrinsic laryngeal muscles. As University libraries become increasingly engaged in offering inexpensive 3D printing services it may soon become common place for both student and educator to access websites, download free models or 3D body parts and only pay the costs of print consumables. Novel models can be manufactured as dissectible, functional multi-layered units and offer rich possibilities for sectional and/or reduced anatomy. This approach can liberate the anatomist from constraints of inflexible hard models or plastinated specimens and engage in the design of class specific models of the future. Anat Sci Educ. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  20. Modelling of aortic aneurysm and aortic dissection through 3D printing.

    PubMed

    Ho, Daniel; Squelch, Andrew; Sun, Zhonghua

    2017-03-01

    The aim of this study was to assess if the complex anatomy of aortic aneurysm and aortic dissection can be accurately reproduced from a contrast-enhanced computed tomography (CT) scan into a three-dimensional (3D) printed model. Contrast-enhanced cardiac CT scans from two patients were post-processed and produced as 3D printed thoracic aorta models of aortic aneurysm and aortic dissection. The transverse diameter was measured at five anatomical landmarks for both models, compared across three stages: the original contrast-enhanced CT images, the stereolithography (STL) format computerised model prepared for 3D printing and the contrast-enhanced CT of the 3D printed model. For the model with aortic dissection, measurements of the true and false lumen were taken and compared at two points on the descending aorta. Three-dimensional printed models were generated with strong and flexible plastic material with successful replication of anatomical details of aortic structures and pathologies. The mean difference in transverse vessel diameter between the contrast-enhanced CT images before and after 3D printing was 1.0 and 1.2 mm, for the first and second models respectively (standard deviation: 1.0 mm and 0.9 mm). Additionally, for the second model, the mean luminal diameter difference between the 3D printed model and CT images was 0.5 mm. Encouraging results were achieved with regards to reproducing 3D models depicting aortic aneurysm and aortic dissection. Variances in vessel diameter measurement outside a standard deviation of 1 mm tolerance indicate further work is required into the assessment and accuracy of 3D model reproduction. © 2017 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

  1. Workflow modeling in the graphic arts and printing industry

    NASA Astrophysics Data System (ADS)

    Tuijn, Chris

    2003-12-01

    The last few years, a lot of effort has been spent on the standardization of the workflow in the graphic arts and printing industry. The main reasons for this standardization are two-fold: first of all, the need to represent all aspects of products, processes and resources in a uniform, digital framework and, secondly, the need to have different systems communicate with each other without having to implement dedicated drivers or protocols. Since many years, a number of organizations in the IT sector have been quite busy developing models and languages on the topic of workflow modeling. In addition to the more formal methods (such as, e.g., extended finite state machines, Petri Nets, Markov Chains etc.) introduced a number of decades ago, more pragmatic methods have been proposed quite recently. We hereby think in particular of the activities of the Workflow Management Coalition that resulted in an XML based Process Definition Language. Although one might be tempted to use the already established standards in the graphic environment, one should be well aware of the complexity and uniqueness of the graphic arts workflow. In this paper, we will show that it is quite hard though not impossible to model the graphic arts workflow using the already established workflow systems. After a brief summary of the graphic arts workflow requirements, we will show why the traditional models are less suitable to use. It will turn out that one of the main reasons for the incompatibility is that the graphic arts workflow is primarily resource driven; this means that the activation of processes depends on the status of different incoming resources. The fact that processes can start running with a partial availability of the input resources is a further complication that asks for additional knowledge on process level. In the second part of this paper, we will discuss in more detail the different software components that are available in any graphic enterprise. In the last part, we will

  2. Two-flux transfer matrix model for predicting the reflectance and transmittance of duplex halftone prints.

    PubMed

    Mazauric, Serge; Hébert, Mathieu; Simonot, Lionel; Fournel, Thierry

    2014-12-01

    We introduce a model allowing convenient calculation of the spectral reflectance and transmittance of duplex prints. It is based on flux transfer matrices and enables retrieving classical Kubelka-Munk formulas, as well as extended formulas for nonsymmetric layers. By making different assumptions on the flux transfers, we obtain two predictive models for the duplex halftone prints: the "duplex Clapper-Yule model," which is an extension of the classical Clapper-Yule model, and the "duplex primary reflectance-transmittance model." The two models can be calibrated from either reflectance or transmittance measurements; only the second model can be calibrated from both measurements, thus giving optimal accuracy for both reflectance and transmittance predictions. The conceptual differences between the two models are deeply analyzed, as well as their advantages and drawbacks in terms of calibration. According to the test carried out in this study with paper printed in inkjet, their predictive performances are good provided appropriate calibration options are selected.

  3. 3D Printing of Plant Golgi Stacks from Their Electron Tomographic Models.

    PubMed

    Mai, Keith Ka Ki; Kang, Madison J; Kang, Byung-Ho

    2017-01-01

    Three-dimensional (3D) printing is an effective tool for preparing tangible 3D models from computer visualizations to assist in scientific research and education. With the recent popularization of 3D printing processes, it is now possible for individual laboratories to convert their scientific data into a physical form suitable for presentation or teaching purposes. Electron tomography is an electron microscopy method by which 3D structures of subcellular organelles or macromolecular complexes are determined at nanometer-level resolutions. Electron tomography analyses have revealed the convoluted membrane architectures of Golgi stacks, chloroplasts, and mitochondria. But the intricacy of their 3D organizations is difficult to grasp from tomographic models illustrated on computer screens. Despite the rapid development of 3D printing technologies, production of organelle models based on experimental data with 3D printing has rarely been documented. In this chapter, we present a simple guide to creating 3D prints of electron tomographic models of plant Golgi stacks using the two most accessible 3D printing technologies.

  4. Teleportation of a 3-dimensional GHZ State

    NASA Astrophysics Data System (ADS)

    Cao, Hai-Jing; Wang, Huai-Sheng; Li, Peng-Fei; Song, He-Shan

    2012-05-01

    The process of teleportation of a completely unknown 3-dimensional GHZ state is considered. Three maximally entangled 3-dimensional Bell states function as quantum channel in the scheme. This teleportation scheme can be directly generalized to teleport an unknown d-dimensional GHZ state.

  5. Application of 3-D printing (rapid prototyping) for creating physical models of pediatric orthopedic disorders.

    PubMed

    Starosolski, Zbigniew A; Kan, J Herman; Rosenfeld, Scott D; Krishnamurthy, Rajesh; Annapragada, Ananth

    2014-02-01

    Three-dimensional printing called rapid prototyping, a technology that is used to create physical models based on a 3-D computer representation, is now commercially available and can be created from CT or MRI datasets. This technical innovation paper reviews the specific requirements and steps necessary to apply biomedical 3-D printing of pediatric musculoskeletal disorders. We discuss its role for the radiologist, orthopedist and patient.

  6. Labial morphology: a 3-dimensional anthropometric study.

    PubMed

    Ferrario, Virgilio F; Rosati, Riccardo; Peretta, Redento; Dellavia, Claudia; Sforza, Chiarella

    2009-09-01

    To develop a noninvasive 3-dimensional method to evaluate labial morphology and to assess gender-related differences in healthy young adults. Dental and lip impressions of 11 men and 10 women aged 21 to 34 years, with sound, full, permanent dentition were obtained. The models were digitized and 3-dimensional virtual reproductions obtained. The labial thickness, vermilion area, and volume of the upper and lower lips were measured from the digital reconstructions. The male and female data were compared using Student's t test. The mean lip thickness was significantly larger (P = .02) in men (14.3 mm) than in women (12.3 mm). The lower lip was thicker than the upper lip. The vermilion width was larger in men (75 mm) than in women (70 mm), and no differences were found for vermilion height (10 mm). In the upper lip, the height/width ratio was significantly larger in women (14.1%) than in men (12.3%). The vermilion surface area was slightly larger in men than in women (upper lip area: women, 467 mm(2); men, 501 mm(2); lower lip area: women, 491 mm(2); men, 569 mm(2)). The labial volume was significantly larger in men (upper lip, 2,390 mm(3); lower lip, 2,902 mm(3)) than in women (upper lip, 1,743 mm(3); lower lip, 1,764 mm(3); P = .021). The upper/lower lip area and volume ratios were similar in the 2 genders. Overall, men had larger lips than women. The inferior lip height/width ratio was similar in both genders, and men had a relatively thinner upper lip than women.

  7. Application of Fused Deposition Modelling (FDM) Method of 3D Printing in Drug Delivery.

    PubMed

    Long, Jingjunjiao; Gholizadeh, Hamideh; Lu, Jun; Bunt, Craig; Seyfoddin, Ali

    2017-01-01

    Three-dimensional (3D) printing is an emerging manufacturing technology for biomedical and pharmaceutical applications. Fused deposition modelling (FDM) is a low cost extrusion-based 3D printing technique that can deposit materials layer-by-layer to create solid geometries. This review article aims to provide an overview of FDM based 3D printing application in developing new drug delivery systems. The principle methodology, suitable polymers and important parameters in FDM technology and its applications in fabrication of personalised tablets and drug delivery devices are discussed in this review. FDM based 3D printing is a novel and versatile manufacturing technique for creating customised drug delivery devices that contain accurate dose of medicine( s) and provide controlled drug released profiles.

  8. 3-dimensional Oil Drift Simulations

    NASA Astrophysics Data System (ADS)

    Wettre, C.; Reistad, M.; Hjøllo, B.Å.

    Simulation of oil drift has been an ongoing activity at the Norwegian Meteorological Institute since the 1970's. The Marine Forecasting Centre provides a 24-hour service for the Norwegian Pollution Control Authority and the oil companies operating in the Norwegian sector. The response time is 30 minutes. From 2002 the service is extended to simulation of oil drift from oil spills in deep water, using the DeepBlow model developed by SINTEF Applied Chemistry. The oil drift model can be applied both for instantaneous and continuous releases. The changes in the mass of oil and emulsion as a result of evaporation and emulsion are computed. For oil spill at deep water, hydrate formation and gas dissolution are taken into account. The properties of the oil depend on the oil type, and in the present version 64 different types of oil can be simulated. For accurate oil drift simulations it is important to have the best possible data on the atmospheric and oceanic conditions. The oil drift simulations at the Norwegian Meteorological Institute are always based on the most updated data from numerical models of the atmosphere and the ocean. The drift of the surface oil is computed from the vectorial sum of the surface current from the ocean model and the wave induced Stokes drift computed from wave energy spectra from the wave prediction model. In the new model the current distribution with depth is taken into account when calculating the drift of the dispersed oil droplets. Salinity and temperature profiles from the ocean model are needed in the DeepBlow model. The result of the oil drift simulations can be plotted on sea charts used for navigation, either as trajectory plots or particle plots showing the situation at a given time. The results can also be sent as data files to be included in the user's own GIS system.

  9. Early experiences of planning stereotactic radiosurgery using 3D printed models of eyes with uveal melanomas.

    PubMed

    Furdová, Alena; Sramka, Miron; Thurzo, Andrej; Furdová, Adriana

    2017-01-01

    The objective of this study was to determine the use of 3D printed model of an eye with intraocular tumor for linear accelerator-based stereotactic radiosurgery. The software for segmentation (3D Slicer) created virtual 3D model of eye globe with tumorous mass based on tissue density from computed tomography and magnetic resonance imaging data. A virtual model was then processed in the slicing software (Simplify3D(®)) and printed on 3D printer using fused deposition modeling technology. The material that was used for printing was polylactic acid. In 2015, stereotactic planning scheme was optimized with the help of 3D printed model of the patient's eye with intraocular tumor. In the period 2001-2015, a group of 150 patients with uveal melanoma (139 choroidal melanoma and 11 ciliary body melanoma) were treated. The median tumor volume was 0.5 cm(3) (0.2-1.6 cm(3)). The radiation dose was 35.0 Gy by 99% of dose volume histogram. The 3D printed model of eye with tumor was helpful in planning the process to achieve the optimal scheme for irradiation which requires high accuracy of defining the targeted tumor mass and critical structures.

  10. Early experiences of planning stereotactic radiosurgery using 3D printed models of eyes with uveal melanomas

    PubMed Central

    Furdová, Alena; Sramka, Miron; Thurzo, Andrej; Furdová, Adriana

    2017-01-01

    Objective The objective of this study was to determine the use of 3D printed model of an eye with intraocular tumor for linear accelerator-based stereotactic radiosurgery. Methods The software for segmentation (3D Slicer) created virtual 3D model of eye globe with tumorous mass based on tissue density from computed tomography and magnetic resonance imaging data. A virtual model was then processed in the slicing software (Simplify3D®) and printed on 3D printer using fused deposition modeling technology. The material that was used for printing was polylactic acid. Results In 2015, stereotactic planning scheme was optimized with the help of 3D printed model of the patient’s eye with intraocular tumor. In the period 2001–2015, a group of 150 patients with uveal melanoma (139 choroidal melanoma and 11 ciliary body melanoma) were treated. The median tumor volume was 0.5 cm3 (0.2–1.6 cm3). The radiation dose was 35.0 Gy by 99% of dose volume histogram. Conclusion The 3D printed model of eye with tumor was helpful in planning the process to achieve the optimal scheme for irradiation which requires high accuracy of defining the targeted tumor mass and critical structures. PMID:28203052

  11. Personalized 3D printed model of kidney and tumor anatomy: a useful tool for patient education.

    PubMed

    Bernhard, Jean-Christophe; Isotani, Shuji; Matsugasumi, Toru; Duddalwar, Vinay; Hung, Andrew J; Suer, Evren; Baco, Eduard; Satkunasivam, Raj; Djaladat, Hooman; Metcalfe, Charles; Hu, Brian; Wong, Kelvin; Park, Daniel; Nguyen, Mike; Hwang, Darryl; Bazargani, Soroush T; de Castro Abreu, Andre Luis; Aron, Monish; Ukimura, Osamu; Gill, Inderbir S

    2016-03-01

    To assess the impact of 3D printed models of renal tumor on patient's understanding of their conditions. Patient understanding of their medical condition and treatment satisfaction has gained increasing attention in medicine. Novel technologies such as additive manufacturing [also termed three-dimensional (3D) printing] may play a role in patient education. A prospective pilot study was conducted, and seven patients with a primary diagnosis of kidney tumor who were being considered for partial nephrectomy were included after informed consent. All patients underwent four-phase multi-detector computerized tomography (MDCT) scanning from which renal volume data were extracted to create life-size patient-specific 3D printed models. Patient knowledge and understanding were evaluated before and after 3D model presentation. Patients' satisfaction with their specific 3D printed model was also assessed through a visual scale. After viewing their personal 3D kidney model, patients demonstrated an improvement in understanding of basic kidney physiology by 16.7 % (p = 0.018), kidney anatomy by 50 % (p = 0.026), tumor characteristics by 39.3 % (p = 0.068) and the planned surgical procedure by 44.6 % (p = 0.026). Presented herein is the initial clinical experience with 3D printing to facilitate patient's pre-surgical understanding of their kidney tumor and surgery.

  12. Using 3D Printing to Create Personalized Brain Models for Neurosurgical Training and Preoperative Planning.

    PubMed

    Ploch, Caitlin C; Mansi, Chris S S A; Jayamohan, Jayaratnam; Kuhl, Ellen

    2016-06-01

    Three-dimensional (3D) printing holds promise for a wide variety of biomedical applications, from surgical planning, practicing, and teaching to creating implantable devices. The growth of this cheap and easy additive manufacturing technology in orthopedic, plastic, and vascular surgery has been explosive; however, its potential in the field of neurosurgery remains underexplored. A major limitation is that current technologies are unable to directly print ultrasoft materials like human brain tissue. In this technical note, the authors present a new technology to create deformable, personalized models of the human brain. The method combines 3D printing, molding, and casting to create a physiologically, anatomically, and tactilely realistic model based on magnetic resonance images. Created from soft gelatin, the model is easy to produce, cost-efficient, durable, and orders of magnitude softer than conventionally printed 3D models. The personalized brain model cost $50, and its fabrication took 24 hours. In mechanical tests, the model stiffness (E = 25.29 ± 2.68 kPa) was 5 orders of magnitude softer than common 3D printed materials, and less than an order of magnitude stiffer than mammalian brain tissue (E = 2.64 ± 0.40 kPa). In a multicenter surgical survey, model size (100.00%), visual appearance (83.33%), and surgical anatomy (81.25%) were perceived as very realistic. The model was perceived as very useful for patient illustration (85.00%), teaching (94.44%), learning (100.00%), surgical training (95.00%), and preoperative planning (95.00%). With minor refinements, personalized, deformable brain models created via 3D printing will improve surgical training and preoperative planning with the ultimate goal to provide accurate, customized, high-precision treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Production of accurate skeletal models of domestic animals using three-dimensional scanning and printing technology.

    PubMed

    Li, Fangzheng; Liu, Chunying; Song, Xuexiong; Huan, Yanjun; Gao, Shansong; Jiang, Zhongling

    2017-09-15

    Access to adequate anatomical specimens can be an important aspect in learning the anatomy of domestic animals. In this study, the authors utilized a structured light scanner and fused deposition modeling (FDM) printer to produce highly accurate animal skeletal models. First, various components of the bovine skeleton, including the femur, the fifth rib, and the sixth cervical (C6) vertebra were used to produce digital models. These were then used to produce 1:1 scale physical models with the FDM printer. The anatomical features of the digital models and three-dimensional (3D) printed models were then compared with those of the original skeletal specimens. The results of this study demonstrated that both digital and physical scale models of animal skeletal components could be rapidly produced using 3D printing technology. In terms of accuracy between models and original specimens, the standard deviations of the femur and the fifth rib measurements were 0.0351 and 0.0572, respectively. All of the features except the nutrient foramina on the original bone specimens could be identified in the digital and 3D printed models. Moreover, the 3D printed models could serve as a viable alternative to original bone specimens when used in anatomy education, as determined from student surveys. This study demonstrated an important example of reproducing bone models to be used in anatomy education and veterinary clinical training. Anat Sci Educ. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  14. Three-Dimensional Printing and Medical Imaging: A Review of the Methods and Applications.

    PubMed

    Marro, Alessandro; Bandukwala, Taha; Mak, Walter

    2016-01-01

    The purpose of this article is to review recent innovations on the process and application of 3-dimensional (3D) printed objects from medical imaging data. Data for 3D printed medical models can be obtained from computed tomography, magnetic resonance imaging, and ultrasound using the Data Imaging and Communications in Medicine (DICOM) software. The data images are processed using segmentation and mesh generation tools and converted to a standard tessellation language (STL) file for printing. 3D printing technologies include stereolithography, selective laser sintering, inkjet, and fused-deposition modeling . 3D printed models have been used for preoperative planning of complex surgeries, the creation of custom prosthesis, and in the education and training of physicians. The application of medical imaging and 3D printers has been successful in providing solutions to many complex medical problems. As technology advances, its applications continue to grow in the future. Copyright © 2015 Mosby, Inc. All rights reserved.

  15. 3DHYDROGEOCHEM: A 3-DIMENSIONAL MODEL OF DENSITY-DEPENDENT SUBSURFACE FLOW AND THERMAL MULTISPECIES-MULTICOMPONENT HYDROGEOCHEMICAL TRANSPORT (EPA/600/SR-98/159)

    EPA Science Inventory

    This report presents a three-dimensional finite-element numerical model designed to simulate chemical transport in subsurface systems with temperature effect taken into account. The three-dimensional model is developed to provide (1) a tool of application, with which one is able ...

  16. 3DHYDROGEOCHEM: A 3-DIMENSIONAL MODEL OF DENSITY-DEPENDENT SUBSURFACE FLOW AND THERMAL MULTISPECIES-MULTICOMPONENT HYDROGEOCHEMICAL TRANSPORT (EPA/600/SR-98/159)

    EPA Science Inventory

    This report presents a three-dimensional finite-element numerical model designed to simulate chemical transport in subsurface systems with temperature effect taken into account. The three-dimensional model is developed to provide (1) a tool of application, with which one is able ...

  17. Phase diagram of quark-antiquark and diquark condensates in the 3-dimensional Gross-Neveu model with the 4-component spinor representation

    SciTech Connect

    Kohyama, Hiroaki

    2008-07-01

    We construct the phase diagram of the quark-antiquark and diquark condensates at finite temperature and density in the 2+1 dimensional (3D) two flavor massless Gross-Neveu (GN) model with the 4-component quarks. In contrast to the case of the 2-component quarks, there appears the coexisting phase of the quark-antiquark and diquark condensates. This is the crucial difference between the 2-component and 4-component quark cases in the 3D GN model. The coexisting phase is also seen in the 4D Nambu Jona-Lasinio model. Then we see that the 3D GN model with the 4-component quarks bears closer resemblance to the 4D Nambu Jona-Lasinio model.

  18. The Accuracy and Applicability of 3D Modeling and Printing Blunt Force Cranial Injuries.

    PubMed

    Edwards, Julie; Rogers, Tracy

    2017-08-23

    The purpose of this study was to determine the factors affecting the accuracy of 3D models and 3D prints of cranial blunt force trauma, to evaluate the applicability and limitations of modeling such injuries. Three types of cranial blunt force lesions were documented (hinge, depressed, and comminuted) using three forms of surface scanning (laser, structured light scanner, and photogrammetry) at two different quality settings (standard and high). 3D printed models of the lesions were produced using two different materials (a gypsum-like composite powder called VisiJet(®) PXL and an acrylic engineered composite plastic called VisiJet(®) M3 in crystal colour). The results of these analyzes indicate the prints in this study exhibit some statistically significant differences from the actual bone lesions, but details of the lesions can be reproduced to within 2 mm accuracy. © 2017 American Academy of Forensic Sciences.

  19. Utility of a 3-dimensional full-scale NaCl model for rib strut grafting for anterior fusion for cervicothoracic kyphosis

    PubMed Central

    Kobayashi, Kazuyoshi; Imagama, Shiro; Muramoto, Akio; Ito, Zenya; Ando, Kei; Yagi, Hideki; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Ishiguro, Naoki

    2015-01-01

    ABSTRACT In severe spinal deformity, pain and neurological disorder may be caused by spinal cord compression. Surgery for spinal reconstruction is desirable, but may be difficult in a case with severe deformity. Here, we show the utility of a 3D NaCl (salt) model in preoperative planning of anterior reconstruction using a rib strut in a 49-year-old male patient with cervicothoracic degenerative spondylosis. We performed surgery in two stages: a posterior approach with decompression and posterior instrumentation with a pedicle screw; followed by a second operation using an anterior approach, for which we created a 3D NaCl model including the cervicothoracic lesion, spinal deformity, and ribs for anterior reconstruction. The 3D NaCl model was easily scraped compared with a conventional plaster model and was useful for planning of resection and identification of a suitable rib for grafting in a preoperative simulation. Surgery was performed successfully with reference to the 3D NaCl model. We conclude that preoperative simulation with a 3D NaCl model contributes to performance of anterior reconstruction using a rib strut in a case of cervicothoracic deformity. PMID:26412901

  20. A 3-dimensional trimeric β-barrel model for Chlamydia MOMP contains conserved and novel elements of Gram-negative bacterial porins.

    PubMed

    Feher, Victoria A; Randall, Arlo; Baldi, Pierre; Bush, Robin M; de la Maza, Luis M; Amaro, Rommie E

    2013-01-01

    Chlamydia trachomatis is the most prevalent cause of bacterial sexually transmitted diseases and the leading cause of preventable blindness worldwide. Global control of Chlamydia will best be achieved with a vaccine, a primary target for which is the major outer membrane protein, MOMP, which comprises ~60% of the outer membrane protein mass of this bacterium. In the absence of experimental structural information on MOMP, three previously published topology models presumed a16-stranded barrel architecture. Here, we use the latest β-barrel prediction algorithms, previous 2D topology modeling results, and comparative modeling methodology to build a 3D model based on the 16-stranded, trimeric assumption. We find that while a 3D MOMP model captures many structural hallmarks of a trimeric 16-stranded β-barrel porin, and is consistent with most of the experimental evidence for MOMP, MOMP residues 320-334 cannot be modeled as β-strands that span the entire membrane, as is consistently observed in published 16-stranded β-barrel crystal structures. Given the ambiguous results for β-strand delineation found in this study, recent publications of membrane β-barrel structures breaking with the canonical rule for an even number of β-strands, findings of β-barrels with strand-exchanged oligomeric conformations, and alternate folds dependent upon the lifecycle of the bacterium, we suggest that although the MOMP porin structure incorporates canonical 16-stranded conformations, it may have novel oligomeric or dynamic structural changes accounting for the discrepancies observed.

  1. Modeling micro-droplet formation in near-field electrohydrodynamic jet printing

    NASA Astrophysics Data System (ADS)

    Popell, George Colin

    Near-field electrohydrodynamic jet (E-jet) printing has recently gained significant interest within the manufacturing research community because of its ability to produce micro/sub-micron-scale droplets using a wide variety of inks and substrates. However, the process currently operates in open-loop and as a result suffers from unpredictable printing quality. The use of physics-based, control-oriented process models is expected to enable closed-loop control of this printing technique. The objective of this research is to perform a fundamental study of the substrate-side droplet shape-evolution in near-field E-jet printing and to develop a physics-based model of the same that links input parameters such as voltage magnitude and ink properties to the height and diameter of the printed droplet. In order to achieve this objective, a synchronized high-speed imaging and substrate-side current-detection system was used implemented to enable a correlation between the droplet shape parameters and the measured current signal. The experimental data reveals characteristic process signatures and droplet spreading regimes. The results of these studies are then used as the basis for a model that predicts the droplet diameter and height using the measured current signal as the input. A unique scaling factor based on the measured current signal is used in this model instead of relying on empirical scaling laws found in literature. For each of the three inks tested in this study, the average absolute error in the model predictions is under 4.6% for diameter predictions and under 10.6% for height predictions of the steady-state droplet. While printing under non-conducive ambient conditions of low humidity and high temperatures, the use of the environmental correction factor in the model is seen to result in average absolute errors of 10.35% and 12.5% for diameter and height predictions.

  2. Should oral implants be splinted in a mandibular implant-supported fixed complete denture? A 3-dimensional-model finite element analysis.

    PubMed

    Alvarez-Arenal, Angel; Brizuela-Velasco, Aritza; DeLlanos-Lanchares, Hector; Gonzalez-Gonzalez, Ignacio

    2014-09-01

    The design of a mandibular fixed complete denture can influence periimplant bone loss. However, the design that transfers the greatest stress to the periimplant bone is not well documented. The purpose of this study was to assess the stress distribution associated with splinted and nonsplinted implant-supported mandibular fixed complete denture designs. Three-dimensional finite element models simulating 6 osseointegrated implants were created in the mandible to support a cobalt-chromium alloy and feldspathic porcelain veneering framework. One model simulated a 1-piece framework, and the other models simulated 2-piece and 3-piece frameworks. Axial and oblique loads were applied to the frameworks. For all the models, the greatest stress values were recorded in the periimplant bone of posterior implants, with differences between the left and right sides. The axial load transferred greater stress values to the periimplant bone than did the oblique load. The lowest periimplant bone stress values were observed in the 3-piece framework model at all implant locations, with the exception of implants placed in the canine region. A framework separated into 3 pieces transfers the least stress to the periimplant bone. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  3. [3D printing personalized implant manufactured via fused deposition modeling: an accuracy research].

    PubMed

    Wang, Ning; Li, Jie; Wang, Xiaolong; Liu, Gang; Liu, Bin

    2015-10-01

    The aim of this study was to determine the accuracy of personalized implant fabricated via 3D printing and fused deposition modeling technique (FDM) and to compare the results with a real tooth. Six prepared extracted orthodontic teeth (in vivo) were scanned via cone beam computed tomography (CBCT) to obtain 3D data and to build the data models by using Mimics 15.0 software. The extracted orthodontic teeth (in vitro) and the personalized implants designed via 3D printing and FDM were scanned via CBCT to obtain data and to build the data models at the same parameters. The 3D deviations were compared among the in vivo teeth data models, in vitro teeth data models, and printing personalized implant data models by using the Geomagic studio software. The average deviations of high and low areas between date models of in vivo teeth and personalized implants were 0.19 mm and -0.16 mm, respectively, and the average deviations between in vitro and in vivo teeth were 0.14 mm and -0.07 mm, respectively. The independent t test showed that no statistically significant difference was observed between the two groups (P>0.05). 1) The personalized dental implants were manufactured via 3D printing and FDM with a high degree of precision. 2) Errors between the data models of in vitro and in vivo teeth were observed at the same CBCT parameters.

  4. 3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Vaid, Thomas P.

    2014-01-01

    Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…

  5. 3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Vaid, Thomas P.

    2014-01-01

    Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…

  6. Validation of cone beam computed tomography-based tooth printing using different three-dimensional printing technologies.

    PubMed

    Khalil, Wael; EzEldeen, Mostafa; Van De Casteele, Elke; Shaheen, Eman; Sun, Yi; Shahbazian, Maryam; Olszewski, Raphael; Politis, Constantinus; Jacobs, Reinhilde

    2016-03-01

    Our aim was to determine the accuracy of 3-dimensional reconstructed models of teeth compared with the natural teeth by using 4 different 3-dimensional printers. This in vitro study was carried out using 2 intact, dry adult human mandibles, which were scanned with cone beam computed tomography. Premolars were selected for this study. Dimensional differences between natural teeth and the printed models were evaluated directly by using volumetric differences and indirectly through optical scanning. Analysis of variance, Pearson correlation, and Bland Altman plots were applied for statistical analysis. Volumetric measurements from natural teeth and fabricated models, either by the direct method (the Archimedes principle) or by the indirect method (optical scanning), showed no statistical differences. The mean volume difference ranged between 3.1 mm(3) (0.7%) and 4.4 mm(3) (1.9%) for the direct measurement, and between -1.3 mm(3) (-0.6%) and 11.9 mm(3) (+5.9%) for the optical scan. A surface part comparison analysis showed that 90% of the values revealed a distance deviation within the interval 0 to 0.25 mm. Current results showed a high accuracy of all printed models of teeth compared with natural teeth. This outcome opens perspectives for clinical use of cost-effective 3-dimensional printed teeth for surgical procedures, such as tooth autotransplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. A 3-dimensional micro- and nanoparticle transport and filtration model (MNM3D) applied to the migration of carbon-based nanomaterials in porous media

    NASA Astrophysics Data System (ADS)

    Bianco, Carlo; Tosco, Tiziana; Sethi, Rajandrea

    2016-10-01

    Engineered nanoparticles (NPs) in the environment can act both as contaminants, when they are unintentionally released, and as remediation agents when injected on purpose at contaminated sites. In this work two carbon-based NPs are considered, namely CARBO-IRON®, a new material developed for contaminated site remediation, and single layer graphene oxide (SLGO), a potential contaminant of the next future. Understanding and modeling the transport and deposition of such NPs in aquifer systems is a key aspect in both cases, and numerical models capable to simulate NP transport in groundwater in complex 3D scenarios are necessary. To this aim, this work proposes a modeling approach based on modified advection-dispersion-deposition equations accounting for the coupled influence of flow velocity and ionic strength on particle transport. A new modeling tool (MNM3D - Micro and Nanoparticle transport Model in 3D geometries) is presented for the simulation of NPs injection and transport in 3D scenarios. MNM3D is the result of the integration of the numerical code MNMs (Micro and Nanoparticle transport, filtration and clogging Model - Suite) in the well-known transport model RT3D (Clement et al., 1998). The injection in field-like conditions of CARBO-IRON® (20 g/l) amended by CMC (4 g/l) in a 2D vertical tank (0.7 × 1.0 × 0.12 m) was simulated using MNM3D, and compared to experimental results under the same conditions. Column transport tests of SLGO at a concentration (10 mg/l) representative of a possible spill of SLGO-containing waste water were performed at different values of ionic strength (0.1 to 35 mM), evidencing a strong dependence of SLGO transport on IS, and a reversible blocking deposition. The experimental data were fitted using the numerical code MNMs and the ionic strength-dependent transport was up-scaled for a full scale 3D simulation of SLGO release and long-term transport in a heterogeneous aquifer. MNM3D showed to potentially represent a valid tool for

  8. A 3-dimensional micro- and nanoparticle transport and filtration model (MNM3D) applied to the migration of carbon-based nanomaterials in porous media.

    PubMed

    Bianco, Carlo; Tosco, Tiziana; Sethi, Rajandrea

    2016-10-01

    Engineered nanoparticles (NPs) in the environment can act both as contaminants, when they are unintentionally released, and as remediation agents when injected on purpose at contaminated sites. In this work two carbon-based NPs are considered, namely CARBO-IRON®, a new material developed for contaminated site remediation, and single layer graphene oxide (SLGO), a potential contaminant of the next future. Understanding and modeling the transport and deposition of such NPs in aquifer systems is a key aspect in both cases, and numerical models capable to simulate NP transport in groundwater in complex 3D scenarios are necessary. To this aim, this work proposes a modeling approach based on modified advection-dispersion-deposition equations accounting for the coupled influence of flow velocity and ionic strength on particle transport. A new modeling tool (MNM3D - Micro and Nanoparticle transport Model in 3D geometries) is presented for the simulation of NPs injection and transport in 3D scenarios. MNM3D is the result of the integration of the numerical code MNMs (Micro and Nanoparticle transport, filtration and clogging Model - Suite) in the well-known transport model RT3D (Clement et al., 1998). The injection in field-like conditions of CARBO-IRON® (20g/l) amended by CMC (4g/l) in a 2D vertical tank (0.7×1.0×0.12m) was simulated using MNM3D, and compared to experimental results under the same conditions. Column transport tests of SLGO at a concentration (10mg/l) representative of a possible spill of SLGO-containing waste water were performed at different values of ionic strength (0.1 to 35mM), evidencing a strong dependence of SLGO transport on IS, and a reversible blocking deposition. The experimental data were fitted using the numerical code MNMs and the ionic strength-dependent transport was up-scaled for a full scale 3D simulation of SLGO release and long-term transport in a heterogeneous aquifer. MNM3D showed to potentially represent a valid tool for the

  9. Use of 3D printed models in medical education: A randomized control trial comparing 3D prints versus cadaveric materials for learning external cardiac anatomy.

    PubMed

    Lim, Kah Heng Alexander; Loo, Zhou Yaw; Goldie, Stephen J; Adams, Justin W; McMenamin, Paul G

    2016-05-06

    Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized controlled trial was undertaken on undergraduate medical students without prior formal cardiac anatomy teaching. Following a pre-test examining baseline external cardiac anatomy knowledge, participants were randomly assigned to three groups who underwent self-directed learning sessions using either cadaveric materials, 3D prints, or a combination of cadaveric materials/3D prints (combined materials). Participants were then subjected to a post-test written by a third party. Fifty-two participants completed the trial; 18 using cadaveric materials, 16 using 3D models, and 18 using combined materials. Age and time since completion of high school were equally distributed between groups. Pre-test scores were not significantly different (P = 0.231), however, post-test scores were significantly higher for 3D prints group compared to the cadaveric materials or combined materials groups (mean of 60.83% vs. 44.81% and 44.62%, P = 0.010, adjusted P = 0.012). A significant improvement in test scores was detected for the 3D prints group (P = 0.003) but not for the other two groups. The finding of this pilot study suggests that use of 3D prints do not disadvantage students relative to cadaveric materials; maximally, results suggest that 3D may confer certain benefits to anatomy learning and supports their use and ongoing evaluation as supplements to cadaver-based curriculums. Anat Sci Educ 9: 213-221. © 2015 American Association of Anatomists. © 2015 American Association of Anatomists.

  10. Possibilities of Preoperative Medical Models Made by 3D Printing or Additive Manufacturing.

    PubMed

    Salmi, Mika

    2016-01-01

    Most of the 3D printing applications of preoperative models have been focused on dental and craniomaxillofacial area. The purpose of this paper is to demonstrate the possibilities in other application areas and give examples of the current possibilities. The approach was to communicate with the surgeons with different fields about their needs related preoperative models and try to produce preoperative models that satisfy those needs. Ten different kinds of examples of possibilities were selected to be shown in this paper and aspects related imaging, 3D model reconstruction, 3D modeling, and 3D printing were presented. Examples were heart, ankle, backbone, knee, and pelvis with different processes and materials. Software types required were Osirix, 3Data Expert, and Rhinoceros. Different 3D printing processes were binder jetting and material extrusion. This paper presents a wide range of possibilities related to 3D printing of preoperative models. Surgeons should be aware of the new possibilities and in most cases help from mechanical engineering side is needed.

  11. Possibilities of Preoperative Medical Models Made by 3D Printing or Additive Manufacturing

    PubMed Central

    2016-01-01

    Most of the 3D printing applications of preoperative models have been focused on dental and craniomaxillofacial area. The purpose of this paper is to demonstrate the possibilities in other application areas and give examples of the current possibilities. The approach was to communicate with the surgeons with different fields about their needs related preoperative models and try to produce preoperative models that satisfy those needs. Ten different kinds of examples of possibilities were selected to be shown in this paper and aspects related imaging, 3D model reconstruction, 3D modeling, and 3D printing were presented. Examples were heart, ankle, backbone, knee, and pelvis with different processes and materials. Software types required were Osirix, 3Data Expert, and Rhinoceros. Different 3D printing processes were binder jetting and material extrusion. This paper presents a wide range of possibilities related to 3D printing of preoperative models. Surgeons should be aware of the new possibilities and in most cases help from mechanical engineering side is needed. PMID:27433470

  12. Development and Assessment of a Low-Cost 3D-printed Airway Model for Bronchoscopy Simulation Training.

    PubMed

    Byrne, Timothy; Yong, Sarah A; Steinfort, Daniel P

    2016-07-01

    We report upon the techniques used to create a plastic 3-dimensional-printed bronchoscopy trainer from an actual patient computed tomography scan. The formatting methods to create the printable file, using free open access software, are outlined. The resulting high anatomic fidelity part-task trainer is described, as well as experienced bronchoscopists' perception of its realism and utility as a training tool. A discussion of the current state of knowledge about the role of simulation in bronchoscopy training, as well as the potential contribution of this device, is presented.

  13. Upregulated expression of La ribonucleoprotein domain family member 6 and collagen type I gene following water-filtered broad-spectrum near-infrared irradiation in a 3-dimensional human epidermal tissue culture model as revealed by microarray analysis.

    PubMed

    Tanaka, Yohei; Nakayama, Jun

    2017-02-27

    Water-filtered broad-spectrum near-infrared irradiation can induce various biological effects, as our previous clinical, histological, and biochemical investigations have shown. However, few studies that examined the changes thus induced in gene expression. The aim was to investigate the changes in gene expression in a 3-dimensional reconstructed epidermal tissue culture exposed to water-filtered broad-spectrum near-infrared irradiation. DNA microarray and quantitative real-time polymerase chain reaction (PCR) analysis was used to assess gene expression levels in a 3-dimensional reconstructed epidermal model composed of normal human epidermal cells exposed to water-filtered broad-spectrum near-infrared irradiation. The water filter allowed 1000-1800 nm wavelengths and excluded 1400-1500 nm wavelengths, and cells were exposed to 5 or 10 rounds of near-infrared irradiation at 10 J/cm(2) . A DNA microarray with over 50 000 different probes showed 18 genes that were upregulated or downregulated by at least twofold after irradiation. Quantitative real-time PCR revealed that, relative to control cells, the gene encoding La ribonucleoprotein domain family member 6 (LARP6), which regulates collagen expression, was significantly and dose-dependently upregulated (P < 0.05) by water-filtered broad-spectrum near-infrared exposure. Gene encoding transcripts of collagen type I were significantly upregulated compared with controls (P < 0.05). This study demonstrates the ability of water-filtered broad-spectrum near-infrared irradiation to stimulate the production of type I collagen. © 2017 The Australasian College of Dermatologists.

  14. Optimization of 3-dimensional imaging of the breast region with 3-dimensional laser scanners.

    PubMed

    Kovacs, Laszlo; Yassouridis, Alexander; Zimmermann, Alexander; Brockmann, Gernot; Wöhnl, Antonia; Blaschke, Matthias; Eder, Maximilian; Schwenzer-Zimmerer, Katja; Rosenberg, Robert; Papadopulos, Nikolaos A; Biemer, Edgar

    2006-03-01

    The anatomic conditions of the female breast require imaging the breast region 3-dimensionally in a normal standing position for quality assurance and for surgery planning or surgery simulation. The goal of this work was to optimize the imaging technology for the mammary region with a 3-dimensional (3D) laser scanner, to evaluate the precision and accuracy of the method, and to allow optimum data reproducibility. Avoiding the influence of biotic factors, such as mobility, we tested the most favorable imaging technology on dummy models for scanner-related factors such as the scanner position in comparison with the torso and the number of scanners and single shots. The influence of different factors of the breast region, such as different breast shapes or premarking of anatomic landmarks, was also first investigated on dummies. The findings from the dummy models were then compared with investigations on test persons, and the accuracy of measurements on the virtual models was compared with a coincidence analysis of the manually measured values. The best precision and accuracy of breast region measurements were achieved when landmarks were marked before taking the shots and when shots at 30 degrees left and 30 degrees right, relative to the sagittal line, were taken with 2 connected scanners mounted with a +10-degree upward angle. However, the precision of the measurements on test persons was significantly lower than those measured on dummies. Our findings show that the correct settings for 3D imaging of the breast region with a laser scanner can achieve an acceptable degree of accuracy and reproducibility.

  15. 3D Printing of Protein Models in an Undergraduate Laboratory: Leucine Zippers

    ERIC Educational Resources Information Center

    Meyer, Scott C.

    2015-01-01

    An upper-division undergraduate laboratory experiment is described that explores the structure/function relationship of protein domains, namely leucine zippers, through a molecular graphics computer program and physical models fabricated by 3D printing. By generating solvent accessible surfaces and color-coding hydrophobic, basic, and acidic amino…

  16. 3D Printing of Protein Models in an Undergraduate Laboratory: Leucine Zippers

    ERIC Educational Resources Information Center

    Meyer, Scott C.

    2015-01-01

    An upper-division undergraduate laboratory experiment is described that explores the structure/function relationship of protein domains, namely leucine zippers, through a molecular graphics computer program and physical models fabricated by 3D printing. By generating solvent accessible surfaces and color-coding hydrophobic, basic, and acidic amino…

  17. Making the Transition from Print to Electronic Serial Collections: A New Model for Academic Chemistry Libraries?

    ERIC Educational Resources Information Center

    Chrzastowski, Tina E.

    2003-01-01

    Proposes a new model for an academic chemistry library based on experiences at the University of Illinois at Urbana-Champaign in which primary access to journals is electronic and print journals are archived unbound in a remote storage facility following local access for one year. Discusses results of a feasibility study. (Author/LRW)

  18. Application of the model of the printed circuit board with regard to the topology of external conductive layers for calculation of the thermal conditions of the printed circuit board

    NASA Astrophysics Data System (ADS)

    Rybakov, I. M.; Goryachev, N. V.; Kochegarov, I. I.; Grishko, A. K.; Brostilov, S. A.; Yurkov, N. K.

    2017-01-01

    The paper proves the necessity of taking into account external conductive layers of the printed circuit board with the thermal physical designing radio-electronic means. For example, a single printed circuit board shows the level of influence of the external conductive layer on the thermal conditions of the printed circuit board. It proved the influence of Joule heat in the thermal conditions of a single conductor. Developed geometrical and thermal printed circuit board models take into account the topological layer and can improve the accuracy of determining the thermal conditions of the printed circuit board.

  19. 3-dimensional imaging at nanometer resolutions

    DOEpatents

    Werner, James H.; Goodwin, Peter M.; Shreve, Andrew P.

    2010-03-09

    An apparatus and method for enabling precise, 3-dimensional, photoactivation localization microscopy (PALM) using selective, two-photon activation of fluorophores in a single z-slice of a sample in cooperation with time-gated imaging for reducing the background radiation from other image planes to levels suitable for single-molecule detection and spatial location, are described.

  20. Elastic Properties of 3D-Printed Rock Models: Dry and Saturated Cracks

    NASA Astrophysics Data System (ADS)

    Huang, L.; Stewart, R.; Dyaur, N.

    2014-12-01

    Many regions of subsurface interest are, or will be, fractured. In addition, these zones many be subject to varying saturations and stresses. New 3D printing techniques using different materials and structures, provide opportunities to understand porous or fractured materials and fluid effects on their elastic properties. We use a 3D printer (Stratasys Dimension SST 768) to print two rock models: a solid octahedral prism and a porous cube with thousands of penny-shaped cracks. The printing material is ABS thermal plastic with a density of 1.04 g/cm3. After printing, we measure the elastic properties of the models, both dry and 100% saturated with water. Both models exhibit VTI (Vertical Transverse Isotropic) symmetry due to laying (about 0.25 mm thick) of the printing process. The prism has a density of 0.96 g/cm3 before saturation and 1.00 g/cm3 after saturation. Its effective porosity is calculated to be 4 %. We use ultrasonic transducers (500 kHz) to measure both P- and shear-wave velocities, and the raw material has a P-wave velocity of 1.89 km/s and a shear-wave velocity of 0.91 km/s. P-wave velocity in the un-saturated prism increases from 1.81 km/s to 1.84 km/s after saturation in the direction parallel to layering and from 1.73 km/s to 1.81 km/s in the direction perpendicular to layering. The fast shear-wave velocity decreases from 0.88 km/s to 0.87 km/s and the slow shear-wave velocity decreases from 0.82 km/s to 0.81 km/s. The cube, printed with penny-shaped cracks, gives a density of 0.79 g/cm3 and a porosity of 24 %. We measure its P-wave velocity as 1.78 km/s and 1.68 km/s in the direction parallel and perpendicular to the layering, respectively. Its fast shear-wave velocity is 0.88 km/s and slow shear-wave velocity is 0.70 km/s. The penny-shaped cracks have significant influence on the elastic properties of the 3D-printed rock models. To better understand and explain the fluid effects on the elastic properties of the models, we apply the extended

  1. A Novel Temporal Bone Simulation Model Using 3D Printing Techniques.

    PubMed

    Mowry, Sarah E; Jammal, Hachem; Myer, Charles; Solares, Clementino Arturo; Weinberger, Paul

    2015-09-01

    An inexpensive temporal bone model for use in a temporal bone dissection laboratory setting can be made using a commercially available, consumer-grade 3D printer. Several models for a simulated temporal bone have been described but use commercial-grade printers and materials to produce these models. The goal of this project was to produce a plastic simulated temporal bone on an inexpensive 3D printer that recreates the visual and haptic experience associated with drilling a human temporal bone. Images from a high-resolution CT of a normal temporal bone were converted into stereolithography files via commercially available software, with image conversion and print settings adjusted to achieve optimal print quality. The temporal bone model was printed using acrylonitrile butadiene styrene (ABS) plastic filament on a MakerBot 2x 3D printer. Simulated temporal bones were drilled by seven expert temporal bone surgeons, assessing the fidelity of the model as compared with a human cadaveric temporal bone. Using a four-point scale, the simulated bones were assessed for haptic experience and recreation of the temporal bone anatomy. The created model was felt to be an accurate representation of a human temporal bone. All raters felt strongly this would be a good training model for junior residents or to simulate difficult surgical anatomy. Material cost for each model was $1.92. A realistic, inexpensive, and easily reproducible temporal bone model can be created on a consumer-grade desktop 3D printer.

  2. Developing and evaluating printed education materials: a prescriptive model for quality.

    PubMed

    Bernier, M J

    1993-01-01

    Nurses are frequently called upon to develop and evaluate printed education materials (PEMs) in their role as patient educators. This article describes the use of the Evaluating Printed Education Materials (EPEM) model as a prescriptive guide and quality standard for developing new PEMs or critiquing existing ones. Outlined in the five phases of the model are a series of nursing, learning, and instructional design principles that are intended to increase the relevance, readability, and comprehensibility of PEMs for the patients and families who use them. The patient-centered focus of the model makes it applicable across nursing specialty areas and care settings. Examples of how the model can be used in the care of orthopaedic patients are presented.

  3. Alternative models for determining the surface energy components in offset printing.

    PubMed

    Järn, M; Tåg, C-M; Järnström, J; Granqvist, B; Rosenholm, J B

    2006-09-15

    Different ways of calculating surface energy components for substrates used in offset printing are compared. The results of the very useful van Oss-Chaudhury-Good bi-bidentate model (vOCG) are simplified to mono-bidentate and mono-monodentate models. The unbalance in the acid-base values often obtained by the vOCG model is strongly reduced when applying the simple mono-monodentate model. Moreover, the frequently encountered problem of negative square roots of the acid and base components is removed. An attempt to describe the ink transfer during offset printing by calculating theoretical works of adhesion between ink/plate and ink/paper is also made. The effect of paper roughness on the wetting was studied with atomic force microscopy (AFM).

  4. [3D printing in neurosurgery: a specific model for patients with craniosynostosis].

    PubMed

    Jiménez Ormabera, Borja; Díez Valle, Ricardo; Zaratiegui Fernández, Javier; Llorente Ortega, Marcos; Unamuno Iñurritegui, Xabier; Tejada Solís, Sonia

    2017-06-27

    Craniosynostosis is a rare condition and requires a personalised surgical approach, which is why we consider the use of 3D printed models beneficial in the surgical planning of this procedure. Acrylonitrile butadiene styrene plastic skull models were designed and printed from CT images of patients between 3 and 6 months of age with craniosynostosis of different sutures. The models were used to simulate surgical procedures. Four models of four patients with craniosynostosis were produced: two with closure of the metopic suture and two with sagittal suture closure. The mean age of the patients was 5 months (3-6m) and the mean duration of the surgery was 286min (127-380min). The acrylonitrile butadiene styrene plastic models printed for the project proved to be optimal for the simulation of craniosynostosis surgeries, both anatomically and in terms of mechanical properties and reaction to surgical instruments. 3D printers have a wide range of medical applications and they offer an easy and affordable way to produce skull models. The acrylonitrile butadiene styrene material is suitable for the production of operable bone models as it faithfully reproduces the mechanical characteristics of bone tissue. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. The technique for 3D printing patient-specific models for auricular reconstruction.

    PubMed

    Flores, Roberto L; Liss, Hannah; Raffaelli, Samuel; Humayun, Aiza; Khouri, Kimberly S; Coelho, Paulo G; Witek, Lukasz

    2017-06-01

    Currently, surgeons approach autogenous microtia repair by creating a two-dimensional (2D) tracing of the unaffected ear to approximate a three-dimensional (3D) construct, a difficult process. To address these shortcomings, this study introduces the fabrication of patient-specific, sterilizable 3D printed auricular model for autogenous auricular reconstruction. A high-resolution 3D digital photograph was captured of the patient's unaffected ear and surrounding anatomic structures. The photographs were exported and uploaded into Amira, for transformation into a digital (.stl) model, which was imported into Blender, an open source software platform for digital modification of data. The unaffected auricle as digitally isolated and inverted to render a model for the contralateral side. The depths of the scapha, triangular fossa, and cymba were deepened to accentuate their contours. Extra relief was added to the helical root to further distinguish this structure. The ear was then digitally deconstructed and separated into its individual auricular components for reconstruction. The completed ear and its individual components were 3D printed using polylactic acid filament and sterilized following manufacturer specifications. The sterilized models were brought to the operating room to be utilized by the surgeon. The models allowed for more accurate anatomic measurements compared to 2D tracings, which reduced the degree of estimation required by surgeons. Approximately 20 g of the PLA filament were utilized for the construction of these models, yielding a total material cost of approximately $1. Using the methodology detailed in this report, as well as departmentally available resources (3D digital photography and 3D printing), a sterilizable, patient-specific, and inexpensive 3D auricular model was fabricated to be used intraoperatively. This technique of printing customized-to-patient models for surgeons to use as 'guides' shows great promise. Copyright © 2017 European

  6. Bringing Cosmic Objects Down to Earth: An Overview of 3D Modelling and Printing in Astronomy and Astronomy Communication

    NASA Astrophysics Data System (ADS)

    Arcand, K.; Megan, W.; DePasquale, J.; Jubett, A.; Edmonds, P.; DiVona, K.

    2017-09-01

    Three-dimensional (3D) modelling is more than just good fun, it offers a new vehicle to represent and understand scientific data and gives experts and non-experts alike the ability to manipulate models and gain new perspectives on data. This article explores the use of 3D modelling and printing in astronomy and astronomy communication and looks at some of the practical challenges, and solutions, to using 3D modelling, visualisation and printing in this way.

  7. Three-Dimensional Printing of a Hemorrhagic Cervical Cancer Model for Postgraduate Gynecological Training

    PubMed Central

    Ryan, Stephen; Doucet, Gregory; Murphy, Deanna; Turner, Jacqueline

    2017-01-01

    Introduction A realistic hemorrhagic cervical cancer model was three-dimensionally (3D) printed and used in a postgraduate medical simulation training session. Materials and methods Computer-assisted design (CAD) software was the platform of choice to create and refine the cervical model. Once the prototype was finalized, another software allowed for the addition of a neoplastic mass, which included openings for bleeding from the neoplasm and cervical os. 3D printing was done using two desktop printers and three different materials. An emergency medicine simulation case was presented to obstetrics and gynecology residents who were at varying stages of their training. The scenario included history taking and physical examination of a standardized patient. This was a hybrid simulation; a synthetic pelvic task trainer that allowed the placement of the cervical model was connected to the standardized patient. The task trainer was placed under a drape and appeared to extend from the standardized patient’s body. At various points in the simulation, the standardized patient controlled the cervical bleeding through a peripheral venous line. Feedback forms were completed, and the models were discussed and evaluated with staff. Results A final cervical model was created and successfully printed. Overall, the models were reported to be similar to a real cervix. The models bled well. Most models were not sutured during the scenarios, but overall, the value of the printed cervical models was reported to be high. Discussion The models were well received, but it was suggested that more colors be integrated into the cervix in order to better emphasize the intended pathology. The model design requires further improvement, such as the addition of a locking mechanism, in order to ensure that the cervix stays inside the task trainer throughout the simulation. Adjustments to the simulated blood product would allow the bleeding to flow more vigorously. Additionally

  8. Three-Dimensional Printing of a Hemorrhagic Cervical Cancer Model for Postgraduate Gynecological Training.

    PubMed

    Bartellas, Michael; Ryan, Stephen; Doucet, Gregory; Murphy, Deanna; Turner, Jacqueline

    2017-01-01

    A realistic hemorrhagic cervical cancer model was three-dimensionally (3D) printed and used in a postgraduate medical simulation training session. Computer-assisted design (CAD) software was the platform of choice to create and refine the cervical model. Once the prototype was finalized, another software allowed for the addition of a neoplastic mass, which included openings for bleeding from the neoplasm and cervical os. 3D printing was done using two desktop printers and three different materials. An emergency medicine simulation case was presented to obstetrics and gynecology residents who were at varying stages of their training. The scenario included history taking and physical examination of a standardized patient. This was a hybrid simulation; a synthetic pelvic task trainer that allowed the placement of the cervical model was connected to the standardized patient. The task trainer was placed under a drape and appeared to extend from the standardized patient's body. At various points in the simulation, the standardized patient controlled the cervical bleeding through a peripheral venous line. Feedback forms were completed, and the models were discussed and evaluated with staff. A final cervical model was created and successfully printed. Overall, the models were reported to be similar to a real cervix. The models bled well. Most models were not sutured during the scenarios, but overall, the value of the printed cervical models was reported to be high. The models were well received, but it was suggested that more colors be integrated into the cervix in order to better emphasize the intended pathology. The model design requires further improvement, such as the addition of a locking mechanism, in order to ensure that the cervix stays inside the task trainer throughout the simulation. Adjustments to the simulated blood product would allow the bleeding to flow more vigorously. Additionally, a different simulation scenario might be more suitable to

  9. [Digital modeling for the individual mandibular 3D mesh scaffold based on 3D printing technology].

    PubMed

    Yan, Rongzeng; Luo, Danmei; Qin, Xiaoyu; Li, Runxin; Rong, Qiguo; Hu, Min

    2016-05-01

    To investigate an ideal modeling method of designing 3D mesh scaffold substitutes based on tissue engineering to restore mandibular bone defects. By analyzing the theoretical model from titanium scaffolds fabricated by 3D printing, the feasibility and effectiveness of the proposed methodology were verified. Based on the CT scanned data of a subject, the Mimics 15.0 and Geomagic studio 12.0 reverse engineering software were adopted to generate surface model of mandibular bone and the defect area was separated from the 3D model of bone. Then prosthesis was designed via mirror algorithm, in which outer shape was used as the external shape of scaffold. Unigraphics software NX 8.5 was applied on Boolean calculation of subtraction between prosthesis and regular microstructure structure and ANSYS 14.0 software was used to design the inner construction of 3D mesh scaffolds. The topological structure and the geometrical parameters of 3D mesh titanium scaffolds were adjusted according to the aim of optimized structure and maximal strength with minimal weight. The 3D mesh scaffolds solid model through two kinds of computer-aided methods was input into 3D printing equipment to fabricate titanium scaffolds. Individual scaffolds were designed successfully by two modeling methods. The finite element optimization made 10% decrease of the stress peak and volume decrease of 43%, and the porosity increased to 76.32%. This modeling method was validated by 3D printing titanium scaffold to be feasible and effective. 3D printing technology combined with finite element topology optimization to obtain the ideal mandibular 3D mesh scaffold is feasible and effective.

  10. Four-Dimensional (4D) Printing: A New Evolution in Computed Tomography-Guided Stereolithographic Modeling. Principles and Application.

    PubMed

    Chae, Michael P; Hunter-Smith, David J; De-Silva, Inoka; Tham, Stephen; Spychal, Robert T; Rozen, Warren Matthew

    2015-07-01

    Over the last decade, image-guided production of three-dimensional (3D) haptic biomodels, or rapid prototyping (RP), has transformed the way surgeons conduct preoperative planning. In contrast to earlier RP techniques such as stereolithography, 3D printing has introduced fast, affordable office-based manufacturing. We introduce the concept of 4D printing for the first time by introducing time as the fourth dimension to 3D printing. The bones of the thumb ray are 3D printed during various movements to demonstrate four-dimensional (4D) printing. Principles and validation studies are presented here. 4D computed tomography was performed using "single volume acquisition" technology to reduce the exposure to radiation. Three representative scans of each thumb movement (i.e., abduction, opposition, and key pinch) were selected and then models were fabricated using a 3D printer. For validation, the angle between the first and the second metacarpals from the 4D imaging data and the 4D-printed model was recorded and compared. We demonstrate how 4D printing accurately depicts the transition in the position of metacarpals during thumb movement. With a fourth dimension of time, 4D printing delivers complex spatiotemporal anatomical details effortlessly and may substantially improve preoperative planning. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. 3D Printed Modeling of the Mitral Valve for Catheter-Based Structural Interventions.

    PubMed

    Vukicevic, Marija; Puperi, Daniel S; Jane Grande-Allen, K; Little, Stephen H

    2017-02-01

    As catheter-based structural heart interventions become increasingly complex, the ability to effectively model patient-specific valve geometry as well as the potential interaction of an implanted device within that geometry will become increasingly important. Our aim with this investigation was to combine the technologies of high-spatial resolution cardiac imaging, image processing software, and fused multi-material 3D printing, to demonstrate that patient-specific models of the mitral valve apparatus could be created to facilitate functional evaluation of novel trans-catheter mitral valve repair strategies. Clinical 3D transesophageal echocardiography and computed tomography images were acquired for three patients being evaluated for a catheter-based mitral valve repair. Target anatomies were identified, segmented and reconstructed into 3D patient-specific digital models. For each patient, the mitral valve apparatus was digitally reconstructed from a single or fused imaging data set. Using multi-material 3D printing methods, patient-specific anatomic replicas of the mitral valve were created. 3D print materials were selected based on the mechanical testing of elastomeric TangoPlus materials (Stratasys, Eden Prairie, Minnesota, USA) and were compared to freshly harvested porcine leaflet tissue. The effective bending modulus of healthy porcine MV tissue was significantly less than the bending modulus of TangoPlus (p < 0.01). All TangoPlus varieties were less stiff than the maximum tensile elastic modulus of mitral valve tissue (3697.2 ± 385.8 kPa anterior leaflet; 2582.1 ± 374.2 kPa posterior leaflet) (p < 0.01). However, the slopes of the stress-strain toe regions of the mitral valve tissues (532.8 ± 281.9 kPa anterior leaflet; 389.0 ± 156.9 kPa posterior leaflet) were not different than those of the Shore 27, Shore 35, and Shore 27 with Shore 35 blend TangoPlus material (p > 0.95). We have demonstrated that patient-specific mitral valve models can be

  12. The 3-dimensional cellular automata for HIV infection

    NASA Astrophysics Data System (ADS)

    Mo, Youbin; Ren, Bin; Yang, Wencao; Shuai, Jianwei

    2014-04-01

    The HIV infection dynamics is discussed in detail with a 3-dimensional cellular automata model in this paper. The model can reproduce the three-phase development, i.e., the acute period, the asymptotic period and the AIDS period, observed in the HIV-infected patients in a clinic. We show that the 3D HIV model performs a better robustness on the model parameters than the 2D cellular automata. Furthermore, we reveal that the occurrence of a perpetual source to successively generate infectious waves to spread to the whole system drives the model from the asymptotic state to the AIDS state.

  13. A customized bolus produced using a 3-dimensional printer for radiotherapy.

    PubMed

    Kim, Shin-Wook; Shin, Hun-Joo; Kay, Chul Seung; Son, Seok Hyun

    2014-01-01

    Boluses are used in high-energy radiotherapy in order to overcome the skin sparing effect. In practice though, commonly used flat boluses fail to make a perfect contact with the irregular surface of the patient's skin, resulting in air gaps. Hence, we fabricated a customized bolus using a 3-dimensional (3D) printer and evaluated its feasibility for radiotherapy. We designed two kinds of bolus for production on a 3D printer, one of which was the 3D printed flat bolus for the Blue water phantom and the other was a 3D printed customized bolus for the RANDO phantom. The 3D printed flat bolus was fabricated to verify its physical quality. The resulting 3D printed flat bolus was evaluated by assessing dosimetric parameters such as D1.5 cm, D5 cm, and D10 cm. The 3D printed customized bolus was then fabricated, and its quality and clinical feasibility were evaluated by visual inspection and by assessing dosimetric parameters such as Dmax, Dmin, Dmean, D90%, and V90%. The dosimetric parameters of the resulting 3D printed flat bolus showed that it was a useful dose escalating material, equivalent to a commercially available flat bolus. Analysis of the dosimetric parameters of the 3D printed customized bolus demonstrated that it is provided good dose escalation and good contact with the irregular surface of the RANDO phantom. A customized bolus produced using a 3D printer could potentially replace commercially available flat boluses.

  14. Patient-specific indirectly 3D printed mitral valves for pre-operative surgical modelling

    NASA Astrophysics Data System (ADS)

    Ginty, Olivia; Moore, John; Xia, Wenyao; Bainbridge, Dan; Peters, Terry

    2017-03-01

    Significant mitral valve regurgitation affects over 2% of the population. Over the past few decades, mitral valve (MV) repair has become the preferred treatment option, producing better patient outcomes than MV replacement, but requiring more expertise. Recently, 3D printing has been used to assist surgeons in planning optimal treatments for complex surgery, thus increasing the experience of surgeons and the success of MV repairs. However, while commercially available 3D printers are capable of printing soft, tissue-like material, they cannot replicate the demanding combination of echogenicity, physical flexibility and strength of the mitral valve. In this work, we propose the use of trans-esophageal echocardiography (TEE) 3D image data and inexpensive 3D printing technology to create patient specific mitral valve models. Patient specific 3D TEE images were segmented and used to generate a profile of the mitral valve leaflets. This profile was 3D printed and integrated into a mold to generate a silicone valve model that was placed in a dynamic heart phantom. Our primary goal is to use silicone models to assess different repair options prior to surgery, in the hope of optimizing patient outcomes. As a corollary, a database of patient specific models can then be used as a trainer for new surgeons, using a beating heart simulator to assess success. The current work reports preliminary results, quantifying basic morphological properties. The models were assessed using 3D TEE images, as well as 2D and 3D Doppler images for comparison to the original patient TEE data.

  15. Unit: Model for Matter, Inspection Pack, National Trial Print.

    ERIC Educational Resources Information Center

    Australian Science Education Project, Toorak, Victoria.

    Mental and physical models are treated in the Australian Science Education Project trial unit prepared for students in a transitional stage between concrete and abstract reasoning. Students are introduced to the particle model of matter through a series of core activities, including a combination game using nuts and bolts, culminating in a…

  16. Unit: Model for Matter, Inspection Pack, National Trial Print.

    ERIC Educational Resources Information Center

    Australian Science Education Project, Toorak, Victoria.

    Mental and physical models are treated in the Australian Science Education Project trial unit prepared for students in a transitional stage between concrete and abstract reasoning. Students are introduced to the particle model of matter through a series of core activities, including a combination game using nuts and bolts, culminating in a…

  17. Spectral model of an electro-photographic printing system

    NASA Astrophysics Data System (ADS)

    Kriss, Michael A.

    2011-01-01

    At EI 2007 in San Jose, California detailed physical models for monochrome and color electro-photographic printers were presented. These models were based on computer simulations of toner-dot formation for a variety of halftone structures. The optical interactions between the toner-dots and the paper substrate were incorporated by means of an optical scattering function, which allowed for the calculation of optical dot-gain (and physical dot-gain) as function of the halftone structure. The color model used simple red-green-blue channels to measure the effect of the absorption and scattering properties of the cyan, magenta, yellow and black toners on the final half-tone image. The new spectral model uses the full absorption and scattering spectrum of the image toners in calculating the final color image in terms of CIE XYZ values for well-defined color and gray patches. The new spectral model will be used to show the impact of halftone structure and toner-layerorder on conventional dot-on-dot, rotated dot and error diffusion color halftone systems and how to minimize the impact of image toner scattering. The model has been expanded to use the Neugebauer equations to approximate the amount of cyan, magenta, and yellow toners required to give a "good" neutral in the rotated dot halftone and fine tuning is achieved by adjusting the development threshold level for each layer to hold a good neutral over the full tonal range. In addition to the above fine-tuning, cyan, yellow and magenta offsets are used to find an optimum use of the halftone dither patterns. Once a "good" neutral is obtained the impact on dot gain, color reproduction and optimum layer order can studied with an emphasis on how the full spectral model differs from the simpler three-channel model. The model is used to explore the different approaches required in dot-on-dot, rotated dot and error diffusion halftones to achieve good results.

  18. Wetting characteristics of 3-dimensional nanostructured fractal surfaces

    NASA Astrophysics Data System (ADS)

    Davis, Ethan; Liu, Ying; Jiang, Lijia; Lu, Yongfeng; Ndao, Sidy

    2017-01-01

    This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

  19. Three-dimensional printing of a sinus pericranii model: technical note.

    PubMed

    Simonin, Alexandre; Martinerie, Sébastien; Levivier, Marc; Daniel, Roy Thomas

    2017-03-01

    Sinus pericranii (SP) is a rare venous malformation consisting of a single or multiple abnormal emissary veins communicating between intracranial sinuses and dilated epicranial veins. There is no consensus concerning diagnosis, management, and treatment of SP. We report the case of a 4-month-old infant with a SP for whom we used a three-dimensional printed model in order to define the angioarchitecture, improve management, and help parents' understanding of this uncommon condition.

  20. Framework for modeling visual printed image quality from the paper perspective

    NASA Astrophysics Data System (ADS)

    Oittinen, Pirkko; Halonen, Raisa; Kokkonen, Anna; Leisti, Tuomas; Nyman, Göte; Eerola, Tuomas; Lensu, Lasse; Kälviäinen, Heikki; Ritala, Risto; Pulla, Johannes; Mettänen, Marja

    2008-01-01

    Due to the rise in performance of digital printing, image-based applications are gaining popularity. This creates needs for specifying the quality potential of printers and materials in more detail than before. Both production and end-use standpoints are relevant. This paper gives an overview of an on-going study which has the goal of determining a framework model for the visual quality potential of paper in color image printing. The approach is top-down and it is founded on the concept of a layered network model. The model and its subjective, objective and instrumental measurement layers are discussed. Some preliminary findings are presented. These are based on data from samples obtained by printing natural image contents and simple test fields on a wide range of paper grades by ink-jet in a color managed process. Color profiles were paper specific. Visual mean opinion score data by human observers could be accounted for by two or three dimensions. In the first place these are related to brightness and color brightness. Image content has a marked effect on the dimensions. This underlines the challenges in designing the test images.

  1. Three-dimensional Printed Cardiac Models: Applications in the Field of Medical Education, Cardiovascular Surgery, and Structural Heart Interventions.

    PubMed

    Valverde, Israel

    2017-04-01

    In recent years, three-dimensional (3D) printed models have been incorporated into cardiology because of their potential usefulness in enhancing understanding of congenital heart disease, surgical planning, and simulation of structural percutaneous interventions. This review provides an introduction to 3D printing technology and identifies the elements needed to construct a 3D model: the types of imaging modalities that can be used, their minimum quality requirements, and the kinds of 3D printers available. The review also assesses the usefulness of 3D printed models in medical education, specialist physician training, and patient communication. We also review the most recent applications of 3D models in surgical planning and simulation of percutaneous structural heart interventions. Finally, the current limitations of 3D printing and its future directions are discussed to explore potential new applications in this exciting medical field.

  2. Cellular Changes of Stem Cells in 3-Dimensional Culture.

    PubMed

    Green, Matthew P; Hou, Bo

    2017-06-12

    During various operations and procedures, such as distraction osteogenesis and orthodontics, skeletal tissues use mechanotransduction. Mechanotransduction is important for maintaining bone health and converting mechanical forces into biochemical signals. We hypothesized that cells put under mechanical stress would adapt and change morphologically and respond with a decrease in cellular proliferation to accommodate the stress differences. These differences will be measured at the molecular and genetic level. We also wanted to test the practicality of an in vitro 3-dimensional gel model system. We implemented a 3-dimensional cell culture model. The sample was composed of isolated mouse mesenchymal prefibroblast bone marrow cells from the femurs and tibias of 6- to 8-week-old wild-type C57BL6 mice. The cells were seeded on fibronectin-coated hydrogels along with fibrin and nodulin growth factors. The variables tested were a no-force model (control) and a force model. The force model required two 0.1-mm suture pins put through one 0.25-cm length of cell-gel matrix. After the experiments were run to completion, the samples were fixed with 4% paraformaldehyde and embedded in paraffin. Serial sections were cut at a thickness of 5 μm along the long axis for the force construct and encompassing the entire circular area of the control construct. Descriptive and bivariate statistics were computed, and the P value was set at 5%. There was a statistically significant difference between the 2 models. The force model had longer and straighter primary cilia, less apoptosis, and an increase in cell proliferation. In addition, the shape of the cells was markedly different after the experiment. The results of the study suggest cells put under tensile stress have the ability to mechanically sense the environment to provide improved adaptation. Our work also confirms the usefulness of the in vitro 3-dimensional gel model system to mimic in vivo applications. Published by Elsevier

  3. Fused Deposition Modeling (FDM) 3D Printed Tablets for Intragastric Floating Delivery of Domperidone.

    PubMed

    Chai, Xuyu; Chai, Hongyu; Wang, Xiaoyu; Yang, Jingjing; Li, Jin; Zhao, Yan; Cai, Weimin; Tao, Tao; Xiang, Xiaoqiang

    2017-06-06

    The aim of this study was to explore the feasibility of fused deposition modeling (FDM) 3D printing to prepare intragastric floating sustained release (FSR) tablets. Domperidone (DOM), an insoluble weak base, was chosen as a model drug to investigate the potential of FSR in increasing its oral bioavailability and reducing its administration frequency. DOM was successfully loaded into hydroxypropyl cellulose (HPC) filaments using hot melt extrusion (HME). The filaments were then printed into hollow structured tablets through changing the shell numbers and the infill percentages. Physical characterization results indicated that the majority of DOM gradually turned into the amorphous form during the fabrication process. The optimized formulation (contain 10% DOM, with 2 shells and 0% infill) exhibited the sustained release characteristic and was able to float for about 10 h in vitro. Radiographic images showed that the BaSO4-labeled tablets were retained in the stomach of rabbits for more than 8 h. Furthermore, pharmacokinetic studies showed the relative bioavailability of the FSR tablets compared with reference commercial tablets was 222.49 ± 62.85%. All the results showed that FDM based 3D printing might be a promising way to fabricate hollow tablets for the purpose of intragastric floating drug delivery.

  4. Modeling rock specimens through 3D printing: Tentative experiments and prospects

    NASA Astrophysics Data System (ADS)

    Jiang, Quan; Feng, Xiating; Song, Lvbo; Gong, Yahua; Zheng, Hong; Cui, Jie

    2016-02-01

    Current developments in 3D printing (3DP) technology provide the opportunity to produce rock-like specimens and geotechnical models through additive manufacturing, that is, from a file viewed with a computer to a real object. This study investigated the serviceability of 3DP products as substitutes for rock specimens and rock-type materials in experimental analysis of deformation and failure in the laboratory. These experiments were performed on two types of materials as follows: (1) compressive experiments on printed sand-powder specimens in different shapes and structures, including intact cylinders, cylinders with small holes, and cuboids with pre-existing cracks, and (2) compressive and shearing experiments on printed polylactic acid cylinders and molded shearing blocks. These tentative tests for 3DP technology have exposed its advantages in producing complicated specimens with special external forms and internal structures, the mechanical similarity of its product to rock-type material in terms of deformation and failure, and its precision in mapping shapes from the original body to the trial sample (such as a natural rock joint). These experiments and analyses also successfully demonstrate the potential and prospects of 3DP technology to assist in the deformation and failure analysis of rock-type materials, as well as in the simulation of similar material modeling experiments.

  5. Evaluating the Use of Cleft Lip and Palate 3D-Printed Models as a Teaching Aid.

    PubMed

    AlAli, Ahmad B; Griffin, Michelle F; Calonge, Wenceslao M; Butler, Peter E

    2017-08-28

    Visualization tools are essential for effective medical education, to aid students understanding of complex anatomical systems. Three dimensional (3D) printed models are showing a wide-reaching potential in the field of medical education, to aid the interpretation of 2D imaging. This study investigates the use of 3D-printed models in educational seminars on cleft lip and palate, by comparing integrated "hands-on" student seminars, with 2D presentation seminar methods. Cleft lip and palate models were manufactured using 3D-printing technology at the medical school. Sixty-seven students from two medical schools participated in the study. The students were randomly allocated to 2 groups. Knowledge was compared between the groups using a multiple-choice question test before and after the teaching intervention. Group 1 was the control group with a PowerPoint presentation-based educational seminar and group 2 was the test group, with the same PowerPoint presentation, but with the addition of a physical demonstration using 3D-printed models of unilateral and bilateral cleft lips and palate. The level of knowledge gained was established using a preseminar and postseminar assessment, in 2 different institutions, where the addition of the 3D-printed model resulted in a significant improvement in the mean percentage of knowledge gained (44.65% test group; 32.16%; control group; p = 0.038). Student experience was assessed using a postseminar survey, where students felt the 3D-printed model significantly improved the learning experience (p = 0.005) and their visualization (p = 0.001). This study highlights the benefits of the use of 3D-printed models as visualization tools in medical education and the potential of 3D-printing technology to become a standard and effective tool in the interpretation of 2D imaging. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  6. Leaf Printing.

    ERIC Educational Resources Information Center

    Mitchell, Charles W.

    1985-01-01

    Using many different media, students can turn leaves into images which can be used for study, bulletin boards, collections, and identification. The simple techniques described include pastel printing, smoke prints, ink or tempura printing, bleach printing on t-shirts, ditto machine printing using carbon paper, and making cutouts. (DH)

  7. Leaf Printing.

    ERIC Educational Resources Information Center

    Mitchell, Charles W.

    1985-01-01

    Using many different media, students can turn leaves into images which can be used for study, bulletin boards, collections, and identification. The simple techniques described include pastel printing, smoke prints, ink or tempura printing, bleach printing on t-shirts, ditto machine printing using carbon paper, and making cutouts. (DH)

  8. Multiple-image-depth modeling for hotspot and AF printing detections

    NASA Astrophysics Data System (ADS)

    Tang, Y. P.; Chou, C. S.; Huang, W. C.; Liu, R. G.; Gau, T. S.

    2012-03-01

    Typical OPC models focus on predicting wafer contour or CD; therefore, the modeling approach emphasizes careful determination of feature and edge locations in the photo-resist (PR) as well as the exposure threshold, so that the 'cut' model image matches the wafer SEM contours or cut-line CDs most closely. This is an exquisite approach with regard to the contour-based OPC, for the model is calibrated directly from wafer CDs. However, for other applications such as hotspot detection or assist feature (AF) printing prediction that might occur at the top or the bottom of the PR, the typical OPC model approach may not be accurate enough. Usually, these kinds of phenomenon can only be properly described by rigorous simulation, which is very time-consuming and hence not suitable for OPC. In this paper, the approach of building the OPC model with multiple image depths will be discussed. This approach references the images at the bottom and/or the top of the PR. This way, the behavior of the images which are not shown at the normal image depth can be predicted more accurately without distorting the optical model. This compromised OPC modeling approach is beneficial for runtime reduction compared to the rigorous simulation, and for better accuracy compared to conventional model. The applications for AF printing and hotspot predictions using the multiple image depth approach will be demonstrated.

  9. Three dimensional printing as an effective method of producing anatomically accurate models for studies in thermal ecology.

    PubMed

    Watson, Charles M; Francis, Gamal R

    2015-07-01

    Hollow copper models painted to match the reflectance of the animal subject are standard in thermal ecology research. While the copper electroplating process results in accurate models, it is relatively time consuming, uses caustic chemicals, and the models are often anatomically imprecise. Although the decreasing cost of 3D printing can potentially allow the reproduction of highly accurate models, the thermal performance of 3D printed models has not been evaluated. We compared the cost, accuracy, and performance of both copper and 3D printed lizard models and found that the performance of the models were statistically identical in both open and closed habitats. We also find that 3D models are more standard, lighter, durable, and inexpensive, than the copper electroformed models. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Implementation of virtual models from sheet metal forming simulation into physical 3D colour models using 3D printing

    NASA Astrophysics Data System (ADS)

    Junk, S.

    2016-08-01

    Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.

  11. Spectral prediction model for color prints on paper with fluorescent additives.

    PubMed

    Hersch, Roger David

    2008-12-20

    I propose a model for predicting the total reflectance of color halftones printed on paper incorporating fluorescent brighteners. The total reflectance is modeled as the additive superposition of the relative fluorescent emission and the pure reflectance of the color print. The fluorescent emission prediction model accounts for both the attenuation of light by the halftone within the excitation wavelength range and for the attenuation of the fluorescent emission by the same halftone within the emission wavelength range. The model's calibration relies on reflectance measurements of the optically brightened paper and of the solid colorant patches with two illuminants, one including and one excluding the UV components. The part of the model predicting the pure reflectance relies on an ink-spreading extended Clapper-Yule model. On uniformly distributed surface coverages of cyan, magenta, and yellow halftone patches, the proposed model predicts the relative fluorescent emission with a high accuracy (mean DeltaE(94)=0.42 under a D65 standard illuminant). For optically brightened paper exhibiting a moderate fluorescence, the total reflectance prediction improves the spectral reflectance prediction mainly for highlight color halftones, comprising a proportion of paper white above 12%. Applications include the creation of improved printer characterization tables for color management purposes and the prediction of color gamuts for new combinations of optically brightened papers and inks.

  12. Accuracy and reproducibility of linear measurements of resin, plaster, digital and printed study-models.

    PubMed

    Saleh, Waleed K; Ariffin, Emy; Sherriff, Martyn; Bister, Dirk

    2015-01-01

    To compare the accuracy and reproducibility of measurements of on-screen three-dimensional (3D) digital surface models captured by a 3Shape R700™ laser-scanner, with measurements made using a digital caliper on acrylic, plaster models or model replicas. Four sets of typodont models were used. Acrylic models, alginate impressions, plaster models and physical replicas were measured. The 3Shape R700™ laser-scanning device with 3Shape™ software was used for scans and measurements. Linear measurements were recorded for selected landmarks, on each of the physical models and on the 3D digital surface models on ten separate occasions by a single examiner. Comparing measurements taken on the physical models the mean difference of the measurements was 0.32 mm (SD 0.15 mm). For the different methods (physical versus digital) the mean difference was 0.112 mm (SD 0.15 mm). None of the values showed a statistically significant difference (p < 0.05) on the Objet Eden 250™ 3D prints, alginate impressions, plaster and acrylic models. The comparison of measurements on the physical models showed no significant difference. The 3Shape R700™ is a reliable device for capturing surface details of models in a digital format. When comparing measurements taken manually and digitally there was no statistically significant difference. The Objet Eden 250™ 3D prints proved to be as accurate as the original acrylic, plaster, or alginate impressions as was shown by the accuracy of the measurements taken. This confirms that using virtual study models can be a reliable method, replacing traditional plaster models.

  13. Volumetric Analysis of Alveolar Bone Defect Using Three-Dimensional-Printed Models Versus Computer-Aided Engineering.

    PubMed

    Du, Fengzhou; Li, Binghang; Yin, Ningbei; Cao, Yilin; Wang, Yongqian

    2017-03-01

    Knowing the volume of a graft is essential in repairing alveolar bone defects. This study investigates the 2 advanced preoperative volume measurement methods: three-dimensional (3D) printing and computer-aided engineering (CAE). Ten unilateral alveolar cleft patients were enrolled in this study. Their computed tomographic data were sent to 3D printing and CAE software. A simulated graft was used on the 3D-printed model, and the graft volume was measured by water displacement. The volume calculated by CAE software used mirror-reverses technique. The authors compared the actual volumes of the simulated grafts with the CAE software-derived volumes. The average volume of the simulated bone grafts by 3D-printed models was 1.52 mL, higher than the mean volume of 1.47 calculated by CAE software. The difference between the 2 volumes was from -0.18 to 0.42 mL. The paired Student t test showed no statistically significant difference between the volumes derived from the 2 methods. This study demonstrated that the mirror-reversed technique by CAE software is as accurate as the simulated operation on 3D-printed models in unilateral alveolar cleft patients. These findings further validate the use of 3D printing and CAE technique in alveolar defect repairing.

  14. Modeling coverage-dependent ink thickness in ink-jet printing.

    PubMed

    Coppel, Ludovic G; Slavuj, Radovan; Hardeberg, Jon Yngve

    2016-02-10

    We propose a simple extension of the Murray-Davis halftone reflectance model that accounts for the change of ink dot reflectance due to ink spreading. Significant improvement of the prediction accuracy is obtained for a range of paper substrates and printer combinations compared to the classical Yule-Nielsen and Clapper-Yule models. The results show that ink dot thickness dependency is the main factor limiting the validity of the Murray-Davis model and that optical dot gain can be neglected when the model is calibrated for one specific printer, ink, and substrate combination. The proposed model provides a better understanding of the reflectance from halftone prints that contributes to the development of physical models for simpler and faster printer calibration to different substrates.

  15. Classification of (n+3)-dimensional metric n-Lie algebras

    SciTech Connect

    Geng Qiaozhi; Ren Mingming; Chen Zhiqi

    2010-10-15

    In this paper, we focus on (n+3)-dimensional metric n-Lie algebras. To begin with, we give some properties on (n+3)-dimensional n-Lie algebras. Then based on the properties, we obtain the classification of (n+3)-dimensional metric n-Lie algebras.

  16. Circumferential Three-Dimensional-Printed Tracheal Grafts: Research Model Feasibility and Early Results.

    PubMed

    Bhora, Faiz Y; Lewis, Erik E; Rehmani, Sadiq S; Ayub, Adil; Raad, Wissam; Al-Ayoubi, Adnan M; Lebovics, Robert S

    2017-09-01

    Methods for tracheal graft research have presented persistent challenges to investigators, and three-dimensional (3D)-printed biosynthetic grafts offer one potential development platform. We aimed to develop an efficient research platform for customizable circumferential 3D-printed tracheal grafts and evaluate feasibility and early structural integrity with a large-animal model. Virtual 3D models of porcine subject tracheas were generated using preoperative computed tomography scans. Two designs were used to test graft customizability and the limits of the construction process. Designs I and II used 270-degree and 360-degree external polycaprolactone scaffolds, respectively, both encompassing a circumferential extracellular matrix collagen layer. The polycaprolactone scaffolds were made in a fused-deposition modeling 3D printer and customized to the recipient's anatomy. Design I was implanted in 3 pigs and design II in 2 pigs, replacing 4-ring tracheal segments. Data collected included details of graft construction, clinical outcomes, bronchoscopy, and gross and histologic examination. The 3D-printed biosynthetic grafts were produced with high fidelity to the native organ. The fabrication process took 36 hours. Grafts were implanted without immediate complication. Bronchoscopy immediately postoperatively and at 1 week demonstrated patent grafts and appropriate healing. All animals lived beyond a predetermined 1-week survival period. Bronchoscopy at 2 weeks showed significant paraanastomotic granulation tissue, which, along with partial paraanastomotic epithelialization, was confirmed on pathology. Overall survival was 17 to 34 days. We propose a rapid, reproducible, resource efficient method to develop various anatomically precise grafts. Further graft refinement and strategies for granulation tissue management are needed to improve outcomes. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. 3D printing for orthopedic applications: from high resolution cone beam CT images to life size physical models

    NASA Astrophysics Data System (ADS)

    Jackson, Amiee; Ray, Lawrence A.; Dangi, Shusil; Ben-Zikri, Yehuda K.; Linte, Cristian A.

    2017-03-01

    With increasing resolution in image acquisition, the project explores capabilities of printing toward faithfully reflecting detail and features depicted in medical images. To improve safety and efficiency of orthopedic surgery and spatial conceptualization in training and education, this project focused on generating virtual models of orthopedic anatomy from clinical quality computed tomography (CT) image datasets and manufacturing life-size physical models of the anatomy using 3D printing tools. Beginning with raw micro CT data, several image segmentation techniques including thresholding, edge recognition, and region-growing algorithms available in packages such as ITK-SNAP, MITK, or Mimics, were utilized to separate bone from surrounding soft tissue. After converting the resulting data to a standard 3D printing format, stereolithography (STL), the STL file was edited using Meshlab, Netfabb, and Meshmixer. The editing process was necessary to ensure a fully connected surface (no loose elements), positive volume with manifold geometry (geometry possible in the 3D physical world), and a single, closed shell. The resulting surface was then imported into a "slicing" software to scale and orient for printing on a Flashforge Creator Pro. In printing, relationships between orientation, print bed volume, model quality, material use and cost, and print time were considered. We generated anatomical models of the hand, elbow, knee, ankle, and foot from both low-dose high-resolution cone-beam CT images acquired using the soon to be released scanner developed by Carestream, as well as scaled models of the skeletal anatomy of the arm and leg, together with life-size models of the hand and foot.

  18. Control of Grasp and Manipulation by Soft Fingers with 3-Dimensional Deformation

    NASA Astrophysics Data System (ADS)

    Nakashima, Akira; Shibata, Takeshi; Hayakawa, Yoshikazu

    In this paper, we consider control of grasp and manipulation of an object in a 3-dimensional space by a 3-fingered hand robot with soft finger tips. We firstly propose a 3-dimensional deformation model of a hemispherical soft finger tip and verify its relevance by experimental data. Second, we consider the contact kinematics and derive the dynamical equations of the fingers and the object where the 3-dimensional deformation is considered. For the system, we thirdly propose a method to regulate the object and the internal force with the information of the hand, the object and the deformation. A simulation result is presented to show the effectiveness of the control method.

  19. 3D Printing of Preoperative Simulation Models of a Splenic Artery Aneurysm: Precision and Accuracy.

    PubMed

    Takao, Hidemasa; Amemiya, Shiori; Shibata, Eisuke; Ohtomo, Kuni

    2017-05-01

    Three-dimensional (3D) printing is attracting increasing attention in the medical field. This study aimed to apply 3D printing to the production of hollow splenic artery aneurysm models for use in the simulation of endovascular treatment, and to evaluate the precision and accuracy of the simulation model. From 3D computed tomography (CT) angiography data of a splenic artery aneurysm, 10 hollow models reproducing the vascular lumen were created using a fused deposition modeling-type desktop 3D printer. After filling with water, each model was scanned using T2-weighted magnetic resonance imaging for the evaluation of the lumen. All images were coregistered, binarized, and then combined to create an overlap map. The cross-sectional area of the splenic artery aneurysm and its standard deviation (SD) were calculated perpendicular to the x- and y-axes. Most voxels overlapped among the models. The cross-sectional areas were similar among the models, with SDs <0.05 cm(2). The mean cross-sectional areas of the splenic artery aneurysm were slightly smaller than those calculated from the original mask images. The maximum mean cross-sectional areas calculated perpendicular to the x- and y-axes were 3.90 cm(2) (SD, 0.02) and 4.33 cm(2) (SD, 0.02), whereas those calculated from the original mask images were 4.14 cm(2) and 4.66 cm(2), respectively. The mean cross-sectional areas of the afferent artery were, however, almost the same as those calculated from the original mask images. The results suggest that 3D simulation modeling of a visceral artery aneurysm using a fused deposition modeling-type desktop 3D printer and computed tomography angiography data is highly precise and accurate. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  20. Virtual 3-dimensional preoperative planning with the dextroscope for excision of a 4th ventricular ependymoma.

    PubMed

    Anil, S M; Kato, Y; Hayakawa, M; Yoshida, K; Nagahisha, S; Kanno, T

    2007-04-01

    Advances in computer imaging and technology have facilitated enhancement in surgical planning with a 3-dimensional model of the surgical plan of action utilizing advanced visualization tools in order to plan individual interactive operations with the aid of the dextroscope. This provides a proper 3-dimensional imaging insight to the pathological anatomy and sets a new dimension in collaboration for training and education. The case of a seventeen-year-old female, being operated with the aid of a preoperative 3-dimensional virtual reality planning and the practical application of the neurosurgical operation, is presented. This young lady presented with a two-year history of recurrent episodes of severe, global, throbbing headache with episodes of projectile vomiting associated with shoulder pain which progressively worsened. She had no obvious neurological deficits on clinical examination. CT and MRI showed a contrast-enhancing midline posterior fossa space-occupying lesion. Utilizing virtual imaging technology with the aid of a dextroscope which generates stereoscopic images, a 3-dimensional image was produced with the CT and MRI images. A preoperative planning for excision of the lesion was made and a real-time 3-dimensional volume was produced and surgical planning with the dextroscope was made and the lesion excised. Virtual reality has brought new proportions in 3-dimensional planning and management of various complex neuroanatomical problems that are faced during various operations. Integration of 3-dimensional imaging with stereoscopic vision makes understanding the complex anatomy easier and helps improve decision making in patient management.

  1. Soft tissue models: easy and inexpensive flexible 3D printing as a help in surgical planning of cardiovascular disorders

    NASA Astrophysics Data System (ADS)

    Starosolski, Zbigniew; Ezon, David S.; Krishnamurthy, Rajesh; Dodd, Nicholas; Heinle, Jeffrey; Mckenzie, Dean E.; Annapragada, Ananth

    2017-03-01

    We developed a technology that allows a simple desktop 3D printer with dual extruder to fabricate 3D flexible models of Major AortoPulmonary Collateral Arteries. The study was designed to assess whether the flexible 3D printed models could help during surgical planning phase. Simple FDM 3D printers are inexpensive, versatile in use and easy to maintain, but complications arise when the designed model is complex and has tubular structures with small diameter less than 2mm. The advantages of FDM printers are cost and simplicity of use. We use precisely selected materials to overcome the obstacles listed above. Dual extruder allows to use two different materials while printing, which is especially important in the case of fragile structures like pulmonary vessels and its supporting structures. The latter should not be removed by hand to avoid a truncation of the model. We utilize the water soluble PVA as a supporting structure and Poro-Lay filament for flexible model of AortoPulmonary collateral arteries. Poro-Lay filament is different as compared to all the other flexible ones like polymer-based. Poro-Lay is rigid while printing and this allows printing of structures small in diameter. It achieves flexibility after washing out of printed model with water. It becomes soft in touch and gelatinous. Using both PVA and Poro-Lay gives a huge advantage allowing to wash out the supporting structures and achieve flexibility in one washing operation, saving time and avoiding human error with cleaning the model. We evaluated 6 models for MAPCAS surgical planning study. This approach is also cost-effective - an average cost of materials for print is less than $15; models are printed in facility without any delays. Flexibility of 3D printed models approximate soft tissues properly, mimicking Aortopulmonary collateral arteries. Second utilization models has educational value for both residents and patients' family. Simplification of 3D flexible process could help in other models

  2. Collagen-based brain microvasculature model in vitro using three-dimensional printed template

    PubMed Central

    Kim, Jeong Ah; Kim, Hong Nam; Im, Sun-Kyoung; Chung, Seok

    2015-01-01

    We present an engineered three-dimensional (3D) in vitro brain microvasculature system embedded within the bulk of a collagen matrix. To create a hydrogel template for the functional brain microvascular structure, we fabricated an array of microchannels made of collagen I using microneedles and a 3D printed frame. By culturing mouse brain endothelial cells (bEnd.3) on the luminal surface of cylindrical collagen microchannels, we reconstructed an array of brain microvasculature in vitro with circular cross-sections. We characterized the barrier function of our brain microvasculature by measuring transendothelial permeability of 40 kDa fluorescein isothiocyanate-dextran (Stoke's radius of ∼4.5 nm), based on an analytical model. The transendothelial permeability decreased significantly over 3 weeks of culture. We also present the disruption of the barrier function with a hyperosmotic mannitol as well as a subsequent recovery over 4 days. Our brain microvasculature model in vitro, consisting of system-in-hydrogel combined with the widely emerging 3D printing technique, can serve as a useful tool not only for fundamental studies associated with blood-brain barrier in physiological and pathological settings but also for pharmaceutical applications. PMID:25945141

  3. Layer modeling of zinc removal from metallic mixture of waste printed circuit boards by vacuum distillation.

    PubMed

    Gao, Yujie; Li, Xingang; Ding, Hui

    2015-08-01

    A layer model was established to elucidate the mechanism of zinc removal from the metallic mixture of waste printed circuit boards by vacuum distillation. The removal process was optimized by response surface methodology, and the optimum operating conditions were the chamber pressure of 0.1Pa, heating temperature of 923K, heating time of 60.0min, particle size of 70 mesh (0.212mm) and initial mass of 5.25g. Evaporation efficiency of zinc, the response variable, was 99.79%, which indicates that the zinc can be efficiently removed. Based on the experimental results, a mathematical model, which bears on layer structure, evaporation, mass transfer and condensation, interprets the mechanism of the variable effects. Especially, in order to reveal blocking effect on the zinc removal, the Blake-Kozeny-Burke-Plummer equation was introduced into the mass transfer process. The layer model can be applied to a wider range of metal removal by vacuum distillation.

  4. Correlation of 3D Shift and 3D Tilt of the Patella in Patients With Recurrent Dislocation of the Patella and Healthy Volunteers: An In Vivo Analysis Based on 3-Dimensional Computer Models.

    PubMed

    Yamada, Yuzo; Toritsuka, Yukiyoshi; Nakamura, Norimasa; Horibe, Shuji; Sugamoto, Kazuomi; Yoshikawa, Hideki; Shino, Konsei

    2017-08-01

    The concepts of lateral deviation and lateral inclination of the patella, characterized as shift and tilt, have been applied in combination to evaluate patellar malalignment in patients with patellar dislocation. It is not reasonable, however, to describe the 3-dimensional (3D) positional relation between the patella and the femur according to measurements made on 2-dimensional (2D) images. The current study sought to clarify the relation between lateral deviation and inclination of the patella in patients with recurrent dislocation of the patella (RDP) by redefining them via 3D computer models as 3D shift and 3D tilt. Descriptive laboratory study. Altogether, 60 knees from 56 patients with RDP and 15 knees from 10 healthy volunteers were evaluated. 3D shift and tilt of the patella were analyzed with 3D computer models created by magnetic resonance imaging scans obtained at 10° intervals of knee flexion (0°-50°). 3D shift was defined as the spatial distance between the patellar reference point and the midsagittal plane of the femur; it is expressed as a percentage of the interepicondylar width. 3D tilt was defined as the spatial angle between the patellar reference plane and the transepicondylar axis. Correlations between the 2 parameters were assessed with the Pearson correlation coefficient. The patients' mean Pearson correlation coefficient was 0.895 ± 0.186 (range, -0.073 to 0.997; median, 0.965). In all, 56 knees (93%) had coefficients >0.7 (strong correlation); 1 knee (2%), >0.4 (moderate correlation); 2 knees (3%), >0.2 (weak correlation); and 1 knee (2%), <0.2 (no correlation). The mean correlation coefficient of the healthy volunteers was 0.645 ± 0.448 (range, -0.445 to 0.982; median, 0.834). A statistically significant difference was found in the distribution of the correlation coefficients between the patients and the healthy volunteers ( P = .0034). When distribution of the correlation coefficients obtained by the 3D analyses was compared with that

  5. A Customized Bolus Produced Using a 3-Dimensional Printer for Radiotherapy

    PubMed Central

    Kim, Shin-Wook; Shin, Hun-Joo; Kay, Chul Seung; Son, Seok Hyun

    2014-01-01

    Objective Boluses are used in high-energy radiotherapy in order to overcome the skin sparing effect. In practice though, commonly used flat boluses fail to make a perfect contact with the irregular surface of the patient’s skin, resulting in air gaps. Hence, we fabricated a customized bolus using a 3-dimensional (3D) printer and evaluated its feasibility for radiotherapy. Methods We designed two kinds of bolus for production on a 3D printer, one of which was the 3D printed flat bolus for the Blue water phantom and the other was a 3D printed customized bolus for the RANDO phantom. The 3D printed flat bolus was fabricated to verify its physical quality. The resulting 3D printed flat bolus was evaluated by assessing dosimetric parameters such as D1.5 cm, D5 cm, and D10 cm. The 3D printed customized bolus was then fabricated, and its quality and clinical feasibility were evaluated by visual inspection and by assessing dosimetric parameters such as Dmax, Dmin, Dmean, D90%, and V90%. Results The dosimetric parameters of the resulting 3D printed flat bolus showed that it was a useful dose escalating material, equivalent to a commercially available flat bolus. Analysis of the dosimetric parameters of the 3D printed customized bolus demonstrated that it is provided good dose escalation and good contact with the irregular surface of the RANDO phantom. Conclusions A customized bolus produced using a 3D printer could potentially replace commercially available flat boluses. PMID:25337700

  6. A 3D-printed functioning anatomical human middle ear model.

    PubMed

    Kuru, Ismail; Maier, Hannes; Müller, Mathias; Lenarz, Thomas; Lueth, Tim C

    2016-10-01

    The middle ear is a sophisticated and complex structure with a variety of functions, yet a delicate organ prone to injuries due to various reasons. Both, understanding and reconstructing its functions has always been an important topic for researchers from medical and technical background. Currently, human temporal bones are generally used as model for tests, experiments and validation of the numerical results. However, fresh human preparations are not always easily accessible and their mechanical properties vary with time and between individuals. Therefore we have built an anatomically based and functional middle ear model to serve as a reproducible test environment. Our middle ear model was manufactured with the aid of 3D-printing technology. We have segmented the essential functional elements from micro computed tomography data (μCT) of a single temporal bone. The ossicles were 3D-printed by selective laser melting (SLM) and the soft tissues were casted with silicone rubber into 3D-printed molds. The ear canal, the tympanic cavity and the inner ear were artificially designed, but their design ensured the anatomically correct position of the tympanic membrane, ossicular ligaments and the oval window. For the determination of their auditory properties we have conducted two kinds of tests: measurement of the stapes footplate response to sound and tympanometry of the model. Our experiments regarding the sound transmission showed that the model has a similar behavior to a human middle ear. The transfer function has a resonance frequency at around 1 kHz, the stapes' response is almost constant for frequencies below the resonance and a roll-off is observed above the resonance. The tympanometry results show that the compliance of the middle ear model is similar to the compliance of a healthy human middle ear. We also present that we were able to manipulate the transmission behavior, so that healthy or pathological scenarios can be created. For this purpose we have

  7. Infants’ Representations of 3-Dimensional Occluded Objects

    PubMed Central

    Woods, Rebecca J.; Wilcox, Teresa; Armstrong, Jennifer; Alexander, Gerianne

    2012-01-01

    Infants’ ability to represent objects has received significant attention from the developmental research community. With the advent of eye-tracking technology, detailed analysis of infants’ looking patterns during object occlusion have revealed much about the nature of infants’ representations. The current study continues this research by analyzing infants’ looking patterns in a novel manner and by comparing infants’ looking at a simple display in which a single 3-dimensional (3-D) object moves along a continuous trajectory to a more complex display in which two 3-D objects undergo trajectories that are interrupted behind an occluder. Six-month-old infants saw an occlusion sequence in which a ball moved along a linear path, disappeared behind a rectangular screen, and then a ball (ball-ball event) or a box (ball-box event) emerged at the other edge. An eye-tracking system recorded infants’ eye-movements during the event sequence. Results from examination of infants’ attention to the occluder indicate that during the occlusion interval infants looked longer to the side of the occluder behind which the moving occluded object was located, shifting gaze from one side of the occluder to the other as the object(s) moved behind the screen. Furthermore, when events included two objects, infants attended to the spatiotemporal coordinates of the objects longer than when a single object was involved. These results provide clear evidence that infants’ visual tracking is different in response to a one-object display than to a two-object display. Furthermore, this finding suggests that infants may require more focused attention to the hidden position of objects in more complex multiple-object displays and provides additional evidence that infants represent the spatial location of moving occluded objects. PMID:20926138

  8. Blood Pool Segmentation Results in Superior Virtual Cardiac Models than Myocardial Segmentation for 3D Printing.

    PubMed

    Farooqi, Kanwal M; Lengua, Carlos Gonzalez; Weinberg, Alan D; Nielsen, James C; Sanz, Javier

    2016-08-01

    The method of cardiac magnetic resonance (CMR) three-dimensional (3D) image acquisition and post-processing which should be used to create optimal virtual models for 3D printing has not been studied systematically. Patients (n = 19) who had undergone CMR including both 3D balanced steady-state free precession (bSSFP) imaging and contrast-enhanced magnetic resonance angiography (MRA) were retrospectively identified. Post-processing for the creation of virtual 3D models involved using both myocardial (MS) and blood pool (BP) segmentation, resulting in four groups: Group 1-bSSFP/MS, Group 2-bSSFP/BP, Group 3-MRA/MS and Group 4-MRA/BP. The models created were assessed by two raters for overall quality (1-poor; 2-good; 3-excellent) and ability to identify predefined vessels (1-5: superior vena cava, inferior vena cava, main pulmonary artery, ascending aorta and at least one pulmonary vein). A total of 76 virtual models were created from 19 patient CMR datasets. The mean overall quality scores for Raters 1/2 were 1.63 ± 0.50/1.26 ± 0.45 for Group 1, 2.12 ± 0.50/2.26 ± 0.73 for Group 2, 1.74 ± 0.56/1.53 ± 0.61 for Group 3 and 2.26 ± 0.65/2.68 ± 0.48 for Group 4. The numbers of identified vessels for Raters 1/2 were 4.11 ± 1.32/4.05 ± 1.31 for Group 1, 4.90 ± 0.46/4.95 ± 0.23 for Group 2, 4.32 ± 1.00/4.47 ± 0.84 for Group 3 and 4.74 ± 0.56/4.63 ± 0.49 for Group 4. Models created using BP segmentation (Groups 2 and 4) received significantly higher ratings than those created using MS for both overall quality and number of vessels visualized (p < 0.05), regardless of the acquisition technique. There were no significant differences between Groups 1 and 3. The ratings for Raters 1 and 2 had good correlation for overall quality (ICC = 0.63) and excellent correlation for the total number of vessels visualized (ICC = 0.77). The intra-rater reliability was good for Rater A (ICC = 0.65). Three models were successfully printed

  9. Automated feature extraction for 3-dimensional point clouds

    NASA Astrophysics Data System (ADS)

    Magruder, Lori A.; Leigh, Holly W.; Soderlund, Alexander; Clymer, Bradley; Baer, Jessica; Neuenschwander, Amy L.

    2016-05-01

    Light detection and ranging (LIDAR) technology offers the capability to rapidly capture high-resolution, 3-dimensional surface data with centimeter-level accuracy for a large variety of applications. Due to the foliage-penetrating properties of LIDAR systems, these geospatial data sets can detect ground surfaces beneath trees, enabling the production of highfidelity bare earth elevation models. Precise characterization of the ground surface allows for identification of terrain and non-terrain points within the point cloud, and facilitates further discernment between natural and man-made objects based solely on structural aspects and relative neighboring parameterizations. A framework is presented here for automated extraction of natural and man-made features that does not rely on coincident ortho-imagery or point RGB attributes. The TEXAS (Terrain EXtraction And Segmentation) algorithm is used first to generate a bare earth surface from a lidar survey, which is then used to classify points as terrain or non-terrain. Further classifications are assigned at the point level by leveraging local spatial information. Similarly classed points are then clustered together into regions to identify individual features. Descriptions of the spatial attributes of each region are generated, resulting in the identification of individual tree locations, forest extents, building footprints, and 3-dimensional building shapes, among others. Results of the fully-automated feature extraction algorithm are then compared to ground truth to assess completeness and accuracy of the methodology.

  10. A theoretical model of reversible adhesion in shape memory surface relief structures and its application in transfer printing

    NASA Astrophysics Data System (ADS)

    Xue, Yeguang; Zhang, Yihui; Feng, Xue; Kim, Seok; Rogers, John A.; Huang, Yonggang

    2015-04-01

    Transfer printing is an important and versatile tool for deterministic assembly and integration of micro/nanomaterials on unusual substrates, with promising applications in fabrication of stretchable and flexible electronics. The shape memory polymers (SMP) with triangular surface relief structures are introduced to achieve large, reversible adhesion, thereby with potential applications in temperature-controlled transfer printing. An analytic model is established, and it identifies two mechanisms to increase the adhesion: (1) transition of contact mode from the triangular to trapezoidal configurations, and (2) explicit enhancement in the contact area. The surface relief structures are optimized to achieve reversible adhesion and transfer printing. The theoretical model and results presented can be exploited as design guidelines for future applications of SMP in reversible adhesion and stretchable electronics.

  11. 3D printing of textile-based structures by Fused Deposition Modelling (FDM) with different polymer materials

    NASA Astrophysics Data System (ADS)

    Melnikova, R.; Ehrmann, A.; Finsterbusch, K.

    2014-08-01

    3D printing is a form of additive manufacturing, i.e. creating objects by sequential layering, for pre-production or production. After creating a 3D model with a CAD program, a printable file is used to create a layer design which is printed afterwards. While often more expensive than traditional techniques like injection moulding, 3D printing can significantly enhance production times of small parts produced in small numbers, additionally allowing for large flexibility and the possibility to create parts that would be impossible to produce with conventional techniques. The Fused Deposition Modelling technique uses a plastic filament which is pushed through a heated extrusion nozzle melting the material. Depending on the material, different challenges occur in the production process, and the produced part shows different mechanical properties. The article describes some standard and novel materials and their influence on the resulting parts.

  12. Three-Dimensional Printing and Its Applications in Otorhinolaryngology-Head and Neck Surgery.

    PubMed

    Crafts, Trevor D; Ellsperman, Susan E; Wannemuehler, Todd J; Bellicchi, Travis D; Shipchandler, Taha Z; Mantravadi, Avinash V

    2017-06-01

    Objective Three-dimensional (3D)-printing technology is being employed in a variety of medical and surgical specialties to improve patient care and advance resident physician training. As the costs of implementing 3D printing have declined, the use of this technology has expanded, especially within surgical specialties. This article explores the types of 3D printing available, highlights the benefits and drawbacks of each methodology, provides examples of how 3D printing has been applied within the field of otolaryngology-head and neck surgery, discusses future innovations, and explores the financial impact of these advances. Data Sources Articles were identified from PubMed and Ovid MEDLINE. Review Methods PubMed and Ovid Medline were queried for English articles published between 2011 and 2016, including a few articles prior to this time as relevant examples. Search terms included 3-dimensional printing, 3 D printing, otolaryngology, additive manufacturing, craniofacial, reconstruction, temporal bone, airway, sinus, cost, and anatomic models. Conclusions Three-dimensional printing has been used in recent years in otolaryngology for preoperative planning, education, prostheses, grafting, and reconstruction. Emerging technologies include the printing of tissue scaffolds for the auricle and nose, more realistic training models, and personalized implantable medical devices. Implications for Practice After the up-front costs of 3D printing are accounted for, its utilization in surgical models, patient-specific implants, and custom instruments can reduce operating room time and thus decrease costs. Educational and training models provide an opportunity to better visualize anomalies, practice surgical technique, predict problems that might arise, and improve quality by reducing mistakes.

  13. Usefulness Of Three-Dimensional Printing Models for Patients with Stoma Construction

    PubMed Central

    Tominaga, Tetsuro; Takagi, Katsunori; Takeshita, Hiroaki; Miyamoto, Tomo; Shimoda, Kozue; Matsuo, Ayano; Matsumoto, Keitaro; Hidaka, Shigekazu; Yamasaki, Naoya; Sawai, Terumitsu; Nagayasu, Takeshi

    2016-01-01

    The use of patient-specific organ models in three-dimensional printing systems could be helpful for the education of patients and medical students. The aim of this study was to clarify whether the use of patient-specific stoma models is helpful for patient education. From January 2014 to September 2014, 5 patients who underwent colorectal surgery and for whom a temporary or permanent stoma had been created were involved in this study. Three-dimensional stoma models and three-dimensional face plates were created. The patients’ ages ranged from 59 to 81 years. Four patients underwent stoma construction because of rectal cancer, and 1 underwent stoma construction because of colon stenosis secondary to recurrent cancer. All patients were educated about their stoma and potential stoma-associated problems using three-dimensional stoma models, and all practiced cutting face plates using three-dimensional face plates. The models were also used during medical staff conferences to discuss current issues. All patients understood their problems and finally became self-reliant. The recent availability of three-dimensional printers has enabled the creation of many organ models, and full-scale stoma and face plate models are now available for patient education on cutting an appropriately individualized face plate. Thus, three-dimensional printers could enable fewer skin problems than are currently associated with daily stomal care. PMID:27403103

  14. Usefulness Of Three-Dimensional Printing Models for Patients with Stoma Construction.

    PubMed

    Tominaga, Tetsuro; Takagi, Katsunori; Takeshita, Hiroaki; Miyamoto, Tomo; Shimoda, Kozue; Matsuo, Ayano; Matsumoto, Keitaro; Hidaka, Shigekazu; Yamasaki, Naoya; Sawai, Terumitsu; Nagayasu, Takeshi

    2016-01-01

    The use of patient-specific organ models in three-dimensional printing systems could be helpful for the education of patients and medical students. The aim of this study was to clarify whether the use of patient-specific stoma models is helpful for patient education. From January 2014 to September 2014, 5 patients who underwent colorectal surgery and for whom a temporary or permanent stoma had been created were involved in this study. Three-dimensional stoma models and three-dimensional face plates were created. The patients' ages ranged from 59 to 81 years. Four patients underwent stoma construction because of rectal cancer, and 1 underwent stoma construction because of colon stenosis secondary to recurrent cancer. All patients were educated about their stoma and potential stoma-associated problems using three-dimensional stoma models, and all practiced cutting face plates using three-dimensional face plates. The models were also used during medical staff conferences to discuss current issues. All patients understood their problems and finally became self-reliant. The recent availability of three-dimensional printers has enabled the creation of many organ models, and full-scale stoma and face plate models are now available for patient education on cutting an appropriately individualized face plate. Thus, three-dimensional printers could enable fewer skin problems than are currently associated with daily stomal care.

  15. Three-Dimensional Printing Model as a Tool to Assist in Surgery for Large Mandibular Tumour: a Case Report.

    PubMed

    Yusa, Kazuyuki; Yamanochi, Hideyuki; Takagi, Akira; Iino, Mitsuyoshi

    2017-01-01

    Recently, three-dimensional printing models based on preoperative computed tomography and magnetic resonance imaging images have been widely used in medical fields. This study presents an effective use of the three-dimensional printing model in exploring complex spatial relationship between the tumour and surrounding tissue and in simulation surgery based planning of the operative procedure. The patient was a 7-year-old boy with ameloblastic fibro-odontoma. Prior to surgery, a hybrid three-dimensional printing model consisting of the jaw bone, the tumour and the inferior alveolar nerve was fabricated. After the simulation surgery based on this model, enucleation of the tumour, leaving tooth 46 intact (Universal Numbering System by ADA) safe, was planned. Enucleation of the tumour was successfully carried out. One year later, healing was found to be satisfactory both clinically and radiographically. The study presented an effective application of a novel hybrid three-dimensional printing model composed of hard and soft tissues. Such innovations can bring significant benefits, especially to the field of oncological surgery.

  16. A Prototype Educational Model for Hepatobiliary Interventions: Unveiling the Role of Graphic Designers in Medical 3D Printing.

    PubMed

    Javan, Ramin; Zeman, Merissa N

    2017-08-14

    In the context of medical three-dimensional (3D) printing, in addition to 3D reconstruction from cross-sectional imaging, graphic design plays a role in developing and/or enhancing 3D-printed models. A custom prototype modular 3D model of the liver was graphically designed depicting segmental anatomy of the parenchyma containing color-coded hepatic vasculature and biliary tree. Subsequently, 3D printing was performed using transparent resin for the surface of the liver and polyamide material to develop hollow internal structures that allow for passage of catheters and wires. A number of concepts were incorporated into the model. A representative mass with surrounding feeding arterial supply was embedded to demonstrate tumor embolization. A straight narrow hollow tract connecting the mass to the surface of the liver, displaying the path of a biopsy device's needle, and the concept of needle "throw" length was designed. A connection between the middle hepatic and right portal veins was created to demonstrate transjugular intrahepatic portosystemic shunt (TIPS) placement. A hollow amorphous structure representing an abscess was created to allow the demonstration of drainage catheter placement with the formation of pigtail tip. Percutaneous biliary drain and cholecystostomy tube placement were also represented. The skills of graphic designers may be utilized in creating highly customized 3D-printed models. A model was developed for the demonstration and simulation of multiple hepatobiliary interventions, for training purposes, patient counseling and consenting, and as a prototype for future development of a functioning interventional phantom.

  17. 3D Printed Models and Navigation for Skull Base Surgery: Case Report and Virtual Validation.

    PubMed

    Ritacco, Lucas E; Di Lella, Federico; Mancino, Axel; Gonzalez Bernaldo de Quiros, Fernan; Boccio, Carlos; Milano, Federico E

    2015-01-01

    In recent years, computer-assisted surgery tools have become more versatile. Having access to a 3D printed model expands the possibility for surgeons to practice with the particular anatomy of a patient before surgery and improve their skills. Optical navigation is capable of guiding a surgeon according to a previously defined plan. These methods improve accuracy and safety at the moment of executing the operation. We intend to carry on a validation process for computed-assisted tools. The aim of this project is to propose a comparative validation method to enable physicians to evaluate differences between a virtual planned approach trajectory and a real executed course. Summarily, this project is focused on decoding data in order to obtain numerical values so as to establish the quality of surgical procedures.

  18. Biomimetic staggered composites with highly enhanced energy dissipation: Modeling, 3D printing, and testing

    NASA Astrophysics Data System (ADS)

    Zhang, Pu; Heyne, Mary A.; To, Albert C.

    2015-10-01

    We investigate the damping enhancement in a class of biomimetic staggered composites via a combination of design, modeling, and experiment. In total, three kinds of staggered composites are designed by mimicking the structure of bone and nacre. These composite designs are realized by 3D printing a rigid plastic and a viscous elastomer simultaneously. Greatly-enhanced energy dissipation in the designed composites is observed from both the experimental results and theoretical prediction. The designed polymer composites have loss modulus up to ~500 MPa, higher than most of the existing polymers. In addition, their specific loss modulus (up to 0.43 km2/s2) is among the highest of damping materials. The damping enhancement is attributed to the large shear deformation of the viscous soft matrix and the large strengthening effect from the rigid inclusion phase.

  19. Occupational risk perception, safety training, and injury prevention: testing a model in the Italian printing industry.

    PubMed

    Leiter, Michael P; Zanaletti, William; Argentero, Piergiorgio

    2009-01-01

    This study examined occupational risk perception in relation to safety training and injuries. In a printing industry, 350 workers from 6 departments completed a survey. Data analysis showed significant differences in risk perceptions among departments. Differences in risk perception reflected the type of work and the injury incidents in the departments. A structural equation analysis confirmed a model of risk perception on the basis of employees' evaluation of the prevalence and lethalness of hazards as well as the control over hazards they gain from training. The number of injuries sustained was positively related to the perception of risk exposure and negatively related to evaluations about the safety training. The results highlight the importance of training interventions in increasing workers' adoption of safety procedures and prevention of injuries.

  20. Parent and Child Attitudinal Factors in a Model of Children's Print-Concept Knowledge

    ERIC Educational Resources Information Center

    Dobbs-Oates, Jennifer; Pentimonti, Jill M.; Justice, Laura M.; Kaderavek, Joan N.

    2015-01-01

    The present study investigates the role of attitudinal variables, such as children's literacy interest and parents' reading beliefs, in conjunction with home literacy activities (HLA), in predicting children's print-concept knowledge. The objective of the study is to test a theoretical model describing the relationship among these…

  1. A Two-Step Model for Assessing Relative Interest in E-Books Compared to Print

    ERIC Educational Resources Information Center

    Knowlton, Steven A.

    2016-01-01

    Librarians often wish to know whether readers in a particular discipline favor e-books or print books. Because print circulation and e-book usage statistics are not directly comparable, it can be hard to determine the relative interest of readers in the two types of books. This study demonstrates a two-step method by which librarians can assess…

  2. A Model for Managing 3D Printing Services in Academic Libraries

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Sahib, Josh

    2013-01-01

    The appearance of 3D printers in university libraries opens many opportunities for advancing outreach, teaching, and research programs. The University of Alabama (UA) Libraries recently adopted 3D printing technology and maintains an open access 3D Printing Studio. The Studio consists of a 3D printer, multiple 3D design workstations, and other…

  3. A Two-Step Model for Assessing Relative Interest in E-Books Compared to Print

    ERIC Educational Resources Information Center

    Knowlton, Steven A.

    2016-01-01

    Librarians often wish to know whether readers in a particular discipline favor e-books or print books. Because print circulation and e-book usage statistics are not directly comparable, it can be hard to determine the relative interest of readers in the two types of books. This study demonstrates a two-step method by which librarians can assess…

  4. Developing Print Repositories: Models for Shared Preservation and Access. Managing Economic Challenges.

    ERIC Educational Resources Information Center

    Reilly, Bernard F., Jr.

    This study is an outgrowth of recommendations made in a report issued by the Council on Library and Information Resources (CLIR) in 2001 (Nichols and Smith 2001). The report made three broad recommendations for addressing print preservation: (1) Establish regional repositories to house and provide proper treatment of low-use print matter drawn…

  5. A Model for Managing 3D Printing Services in Academic Libraries

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Sahib, Josh

    2013-01-01

    The appearance of 3D printers in university libraries opens many opportunities for advancing outreach, teaching, and research programs. The University of Alabama (UA) Libraries recently adopted 3D printing technology and maintains an open access 3D Printing Studio. The Studio consists of a 3D printer, multiple 3D design workstations, and other…

  6. The role of three-dimensional printed models of skull in anatomy education: a randomized controlled trail.

    PubMed

    Chen, Shi; Pan, Zhouxian; Wu, Yanyan; Gu, Zhaoqi; Li, Man; Liang, Ze; Zhu, Huijuan; Yao, Yong; Shui, Wuyang; Shen, Zhen; Zhao, Jun; Pan, Hui

    2017-04-03

    Three-dimensional (3D) printed models represent educational tools of high quality compared with traditional teaching aids. Colored skull models were produced by 3D printing technology. A randomized controlled trial (RCT) was conducted to compare the learning efficiency of 3D printed skulls with that of cadaveric skulls and atlas. Seventy-nine medical students, who never studied anatomy, were randomized into three groups by drawing lots, using 3D printed skulls, cadaveric skulls, and atlas, respectively, to study the anatomical structures in skull through an introductory lecture and small group discussions. All students completed identical tests, which composed of a theory test and a lab test, before and after a lecture. Pre-test scores showed no differences between the three groups. In post-test, the 3D group was better than the other two groups in total score (cadaver: 29.5 [IQR: 25-33], 3D: 31.5 [IQR: 29-36], atlas: 27.75 [IQR: 24.125-32]; p = 0.044) and scores of lab test (cadaver: 14 [IQR: 10.5-18], 3D: 16.5 [IQR: 14.375-21.625], atlas: 14.5 [IQR: 10-18.125]; p = 0.049). Scores involving theory test, however, showed no difference between the three groups. In this RCT, an inexpensive, precise and rapidly-produced skull model had advantages in assisting anatomy study, especially in structure recognition, compared with traditional education materials.

  7. Experimental model of developing and analysis of lip prints in atypical surface: A metallic straw (bombilla)

    PubMed Central

    Fonseca, Gabriel M.; Bonfigli, Esteban; Cantín, Mario

    2014-01-01

    Background: The interaction between the offender and the victim produces visible or latent prints on objects and utensils. The study of lip prints has reportedly stayed away from the basic cinematic concept of the lip-to-surface relationship. Materials and Methods: Three regular powders were used to reveal the latent lip prints on a typical metallic straw called bombilla, and the revealed prints were photographed, preserved, and analyzed. Results: Better definition was observed in the lower lip print, and nine anatomical patterns were identified, but a higher definition of wrinkles was observed with indestructible white powder. Conclusion: Knowledge of labial dynamics, the real value of the processed surfaces, and the need for testing in field conditions are discussed. PMID:25125921

  8. Characterization of inks and ink application for ink-jet printing: model and simulation.

    PubMed

    Yang, Li

    2003-07-01

    Ink-jet printing quality is determined primarily by, among other factors, the printing engine and its inks. The printing engine controls the process of ink application and the scheme of ink mixing for th e generation of secondary and tertiary colors. The inks selectively absorb different wavelengths from the illumination and result in the visible color output. Therefore characterizations of the output print in terms of ink distribution and volume, the scheme of ink mixing, light absorption, and light scattering are of essential importance in controlling and understanding the quality of the color reproduction. I present a method to characterize the ink volume and the properties of the ink by means of spectral reflectance measurements and simulations. The simulations are based on the Kubelka-Munk theory, whose applicability to ink-jet printing is also discussed.

  9. Chaotic Advection in a Bounded 3-Dimensional Potential Flow

    NASA Astrophysics Data System (ADS)

    Metcalfe, Guy; Smith, Lachlan; Lester, Daniel

    2012-11-01

    3-dimensional potential, or Darcy flows, are central to understanding and designing laminar transport in porous media; however, chaotic advection in 3-dimensional, volume-preserving flows is still not well understood. We show results of advecting passive scalars in a transient 3-dimensional potential flow that consists of a steady dipole flow and periodic reorientation. Even for the most symmetric reorientation protocol, neither of the two invarients of the motion are conserved; however, one invarient is closely shadowed by a surface of revolution constructed from particle paths of the steady flow, creating in practice an adiabatic surface. A consequence is that chaotic regions cover 3-dimensional space, though tubular regular regions are still transport barriers. This appears to be a new mechanism generating 3-dimensional chaotic orbits. These results contast with the experimental and theoretical results for chaotic scalar transport in 2-dimensional Darcy flows. Wiggins, J. Fluid Mech. 654 (2010).

  10. The usefulness of 3-dimensional endoscope systems in endoscopic surgery.

    PubMed

    Egi, Hiroyuki; Hattori, Minoru; Suzuki, Takahisa; Sawada, Hiroyuki; Kurita, Yuichi; Ohdan, Hideki

    2016-10-01

    The image quality and performance of 3-dimensional video image systems has improved along with improvements in technology. However, objective evaluation on the usefulness of 3-dimensional video image systems is insufficient. Therefore, we decided to investigate the usefulness of 3-dimensional video image systems using the objective endoscopic surgery technology evaluating apparatus that we have developed, the Hiroshima University Endoscopic Surgical Assessment Device (HUESAD). The participants were 28 student volunteers enrolled in Hiroshima University (17 men and 11 women, age: median 22.5, range 20-25), with no one having experienced endoscopic surgery training. Testing was carried out by dividing the subjects into two groups to initially carry out HUESAD with 2-dimensional video imaging (N = 14) and with 3-dimensional video imaging (N = 14). Questionnaires were carried out along with the investigation regarding both 2-dimensional and 3-dimensional video imaging. The task was carried out for approximately 15 min regarding both 2-dimensional and 3-dimensional video imaging. Lastly, the Mental Rotation Test, which is a standard space perception ability test, was used to evaluate the space perception ability. No difference was observed in the nauseous and uncomfortable feeling of practitioners between the two groups. Regarding smoothness, no difference was observed between 2-dimensional and 3-dimensional video imaging (p = 0.8665). Deviation (space perception ability) and approaching time (accuracy) were significantly lower with 3-dimensional video imaging compared to 2-dimensional video imaging. Moreover, the approaching time (accuracy) significantly improved in 3-dimensional video imaging compared to 2-dimensional video imaging in the group with low space perception ability (p = 0.0085). Objective evaluation using HUESAD and subjective evaluation by questionnaire revealed that endoscopic surgery techniques significantly improved in 3-dimensional video

  11. An Evaluation of the Instruction Carried out with Printed Laboratory Materials Designed in Accordance with 5E Model: Reflection of Light and Image on a Plane Mirror

    ERIC Educational Resources Information Center

    Ayvaci, Hakan Sevki; Yildiz, Mehmet; Bakirci, Hasan

    2015-01-01

    This study employed a print laboratory material based on 5E model of constructivist learning approach to teach reflection of light and Image on a Plane Mirror. The effect of the instruction which conducted with the designed print laboratory material on academic achievements of prospective science and technology teachers and their attitudes towards…

  12. An Evaluation of the Instruction Carried out with Printed Laboratory Materials Designed in Accordance with 5E Model: Reflection of Light and Image on a Plane Mirror

    ERIC Educational Resources Information Center

    Ayvaci, Hakan Sevki; Yildiz, Mehmet; Bakirci, Hasan

    2015-01-01

    This study employed a print laboratory material based on 5E model of constructivist learning approach to teach reflection of light and Image on a Plane Mirror. The effect of the instruction which conducted with the designed print laboratory material on academic achievements of prospective science and technology teachers and their attitudes towards…

  13. Quantitative 3-dimensional computed tomography analysis of olecranon fractures.

    PubMed

    Lubberts, Bart; Janssen, Stein; Mellema, Jos; Ring, David

    2016-05-01

    Olecranon fractures have variable size of the proximal fragment, patterns of fragmentation, and subluxation of the ulnohumeral joint that might be better understood and categorized on the basis of quantitative 3-dimensional computed tomography analysis. Mayo type I fractures are undisplaced, Mayo type II are displaced and stable, and Mayo type III are displaced and unstable. The last is categorized into anterior and posterior dislocations. The purpose of this study was to further clarify fracture morphology between Mayo type I, II, and III fractures. Three-dimensional models were created for a consecutive series of 78 patients with olecranon fractures that were evaluated with computed tomography. We determined the total number of fracture fragments, the volume and articular surface area of each fracture fragment, and the degree of displacement of the most proximal olecranon fracture fragment. Displaced olecranon fractures were more comminuted than nondisplaced fractures (P = .02). Displaced fractures without ulnohumeral subluxation were smallest in terms of both volume (P < .001) and articular surface involvement (P < .001) of the most proximal olecranon fracture fragment. There was no difference in average displacement of the proximal fragment between displaced fractures with and without ulnohumeral subluxation (P = .74). Anterior olecranon fracture-dislocations created more displaced (P = .04) and smaller proximal fragments than posterior fracture-dislocations (P = .005), with comparable fragmentation on average (P = .60). The ability to quantify volume, articular surface area, displacement, and fragmentation using quantitative 3-dimensional computed tomography should be considered when increased knowledge of fracture morphology and fracture patterns might be useful. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  14. Three-dimensional Printing in Developing Countries

    PubMed Central

    Ibrahim, Ahmed M. S.; Jose, Rod R.; Rabie, Amr N.; Gerstle, Theodore L.; Lee, Bernard T.

    2015-01-01

    Summary: The advent of 3-dimensional (3D) printing technology has facilitated the creation of customized objects. The lack of regulation in developing countries renders conventional means of addressing various healthcare issues challenging. 3D printing may provide a venue for addressing many of these concerns in an inexpensive and easily accessible fashion. These may potentially include the production of basic medical supplies, vaccination beads, laboratory equipment, and prosthetic limbs. As this technology continues to improve and prices are reduced, 3D printing has the potential ability to promote initiatives across the entire developing world, resulting in improved surgical care and providing a higher quality of healthcare to its residents. PMID:26301132

  15. Improving Perceptual Skills with 3-Dimensional Animations.

    ERIC Educational Resources Information Center

    Johns, Janet Faye; Brander, Julianne Marie

    1998-01-01

    Describes three-dimensional computer aided design (CAD) models for every component in a representative mechanical system; the CAD models made it easy to generate 3-D animations that are ideal for teaching perceptual skills in multimedia computer-based technical training. Fifteen illustrations are provided. (AEF)

  16. Creating and Using Interactive, 3D-Printed Models to Improve Student Comprehension of the Bohr Model of the Atom, Bond Polarity, and Hybridization

    ERIC Educational Resources Information Center

    Smiar, Karen; Mendez, J. D.

    2016-01-01

    Molecular model kits have been used in chemistry classrooms for decades but have seen very little recent innovation. Using 3D printing, three sets of physical models were created for a first semester, introductory chemistry course. Students manipulated these interactive models during class activities as a supplement to existing teaching tools for…

  17. Creating and Using Interactive, 3D-Printed Models to Improve Student Comprehension of the Bohr Model of the Atom, Bond Polarity, and Hybridization

    ERIC Educational Resources Information Center

    Smiar, Karen; Mendez, J. D.

    2016-01-01

    Molecular model kits have been used in chemistry classrooms for decades but have seen very little recent innovation. Using 3D printing, three sets of physical models were created for a first semester, introductory chemistry course. Students manipulated these interactive models during class activities as a supplement to existing teaching tools for…

  18. An electrical model of VCSEL as optical transmitter for optical printed circuit board

    NASA Astrophysics Data System (ADS)

    Kim, Do-Kyoon; Yoon, Young-Seol; Choi, Jin-Ho; Kim, Kyung-Min; Choi, Young-Wan; Lee, Seok

    2005-03-01

    Optical interconnection is recent issue for high-speed data transmission. The limitation of high-speed electrical data transmission is caused by impedance mismatching, electric field coupling, microwave loss, and different length of the electrical signal lines. To overcome these limitations, the electrical signal in the current electrical system has to be changed by the optical signal. The most suitable optical source in the OPCB (Optical Printed Circuit Board) is VCSEL (Vertical Cavity Surface Emitting Lasers) that is low-priced and has the characteristic of vertical surface emitting. In this paper, we propose an electrical model of the VCSEL as E/O converting devices for the OPCB. The equivalent circuit of the VCSEL based on the rate equations includes carrier dynamics and material properties. The rate equation parameters are obtained by full analysis based on rate equation and experiment results. The electrical model of the VCSEL has the series resistance determined by I-V characteristic curve, and the parallel capacitance by the parasitic response of the VCSEL chip. The bandwidth of the optical interconnection is analyzed considering those parameters. We design and fabricate the optical transmitter for OPCB considering proposed electrical model of VCSEL.

  19. Bio-inspired ``jigsaw''-like interlocking sutures: Modeling, optimization, 3D printing and testing

    NASA Astrophysics Data System (ADS)

    Malik, I. A.; Mirkhalaf, M.; Barthelat, F.

    2017-05-01

    Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics and glasses. Sutures can generate large deformations, toughness and damping in otherwise all brittle systems and materials. In this study we examine the design and optimization of sutures with a jigsaw puzzle-like geometry, focusing on the non-linear traction behavior generated by the frictional pullout of the jigsaw tabs. We present analytical models which accurately predict the entire pullout response. Pullout strength and energy absorption increase with higher interlocking angles and for higher coefficients of friction, but the associated high stresses in the solid may fracture the tabs. Systematic optimization reveals a counter-intuitive result: the best pullout performance is achieved with interfaces with low coefficient of friction and high interlocking angle. We finally use 3D printing and mechanical testing to verify the accuracy of the models and of the optimization. The models and guidelines we present here can be extended to other types of geometries and sutured materials subjected to other loading/boundary conditions. The nonlinear responses of sutures are particularly attractive to augment the properties and functionalities of inherently brittle materials such as ceramics and glasses.

  20. 3DIVS: 3-Dimensional Immersive Virtual Sculpting

    SciTech Connect

    Kuester, F; Duchaineau, M A; Hamann, B; Joy, K I; Uva, A E

    2001-10-03

    Virtual Environments (VEs) have the potential to revolutionize traditional product design by enabling the transition from conventional CAD to fully digital product development. The presented prototype system targets closing the ''digital gap'' as introduced by the need for physical models such as clay models or mockups in the traditional product design and evaluation cycle. We describe a design environment that provides an intuitive human-machine interface for the creation and manipulation of three-dimensional (3D) models in a semi-immersive design space, focusing on ease of use and increased productivity for both designer and CAD engineers.

  1. "Just-In-Time" Simulation Training Using 3-D Printed Cardiac Models After Congenital Cardiac Surgery.

    PubMed

    Olivieri, Laura J; Su, Lillian; Hynes, Conor F; Krieger, Axel; Alfares, Fahad A; Ramakrishnan, Karthik; Zurakowski, David; Marshall, M Blair; Kim, Peter C W; Jonas, Richard A; Nath, Dilip S

    2016-03-01

    High-fidelity simulation using patient-specific three-dimensional (3D) models may be effective in facilitating pediatric cardiac intensive care unit (PCICU) provider training for clinical management of congenital cardiac surgery patients. The 3D-printed heart models were rendered from preoperative cross-sectional cardiac imaging for 10 patients undergoing congenital cardiac surgery. Immediately following surgical repair, a congenital cardiac surgeon and an intensive care physician conducted a simulation training session regarding postoperative care utilizing the patient-specific 3D model for the PCICU team. After the simulation, Likert-type 0 to 10 scale questionnaire assessed participant perception of impact of the training session. Seventy clinicians participated in training sessions, including 22 physicians, 38 nurses, and 10 ancillary care providers. Average response to whether 3D models were more helpful than standard hand off was 8.4 of 10. Questions regarding enhancement of understanding and clinical ability received average responses of 9.0 or greater, and 90% of participants scored 8 of 10 or higher. Nurses scored significantly higher than other clinicians on self-reported familiarity with the surgery (7.1 vs. 5.8; P = .04), clinical management ability (8.6 vs. 7.7; P = .02), and ability enhancement (9.5 vs. 8.7; P = .02). Compared to physicians, nurses and ancillary providers were more likely to consider 3D models more helpful than standard hand off (8.7 vs. 7.7; P = .05). Higher case complexity predicted greater enhancement of understanding of surgery (P = .04). The 3D heart models can be used to enhance congenital cardiac critical care via simulation training of multidisciplinary intensive care teams. Benefit may be dependent on provider type and case complexity. © The Author(s) 2016.

  2. 3-Dimensional simulation of the grain formation in investment castings

    SciTech Connect

    Gandin, C.A.; Rappaz, M. ); Tintillier, R. . Dept. Materiaux et Procedes-Direction Technique)

    1994-03-01

    A 3-dimensional (3-D) probabilistic model which has been developed previously for the prediction of grain structure formation during solidification is applied to thin superalloy plates produced using the investment-casting process. This model considers the random nucleation and orientation of nuclei formed at the mold surface and in the bulk of the liquid, the growth kinetics of the dendrite tips, and the preferential growth directions of the dendrite trunks and arms. In the present study, the grains are assumed to nucleate at the surface of the mold only. The computed grain structures, as observed in 2-dimensional (2-D) sections made parallel to the mold surface, are compared with experimental micrographs. The grain densities are then deduced as a function of the distance from the mold surface for both the experiment and the simulation. It is shown that these values are in good agreement, thus, providing validation of the grain formation mechanisms built into the 3-D probabilistic model. Finally, this model is further extended to more complex geometries and the 3-D computed grain structure of an equiaxed turbine-blade airfoil is compared with the experimental transverse section micrograph.

  3. Masking mediated print defect visibility predictor

    NASA Astrophysics Data System (ADS)

    Jing, Xiaochen; Nachlieli, Hila; Shaked, Doron; Shiffman, Smadar; Allebach, Jan P.

    2012-01-01

    Banding is a well-known artifact produced by printing systems. It usually appears as lines perpendicular to the process direction of the print. Therefore, banding is an important print quality issue which has been analyzed and assessed by many researchers. However, little literature has focused on the study of the masking effect of content for this kind of print quality issue. Compared with other image and print quality research, our work is focused on the print quality of typical documents printed on a digital commercial printing press. In this paper, we propose a Masking Mediated Print Defect Visibility Predictor (MMPDVP) to predict the visibility of defects in the presence of customer content. The parameters of the algorithm are trained from ground-truth images that have been marked by subjects. The MMPDVP could help the press operator decide whether the print quality is acceptable for specific customer requirements. Ultimately, this model can be used to optimize the print-shop workflow.

  4. 3D printing of high-resolution PLA-based structures by hybrid electrohydrodynamic and fused deposition modeling techniques

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Seong, Baekhoon; Nguyen, VuDat; Byun, Doyoung

    2016-02-01

    Recently, the three-dimensional (3D) printing technique has received much attention for shape forming and manufacturing. The fused deposition modeling (FDM) printer is one of the various 3D printers available and has become widely used due to its simplicity, low-cost, and easy operation. However, the FDM technique has a limitation whereby its patterning resolution is too low at around 200 μm. In this paper, we first present a hybrid mechanism of electrohydrodynamic jet printing with the FDM technique, which we name E-FDM. We then develop a novel high-resolution 3D printer based on the E-FDM process. To determine the optimal condition for structuring, we also investigated the effect of several printing parameters, such as temperature, applied voltage, working height, printing speed, flow-rate, and acceleration on the patterning results. This method was capable of fabricating both high resolution 2D and 3D structures with the use of polylactic acid (PLA). PLA has been used to fabricate scaffold structures for tissue engineering, which has different hierarchical structure sizes. The fabrication speed was up to 40 mm/s and the pattern resolution could be improved to 10 μm.

  5. 3-Dimensional Reproducibility of Natural Head Position

    DTIC Science & Technology

    2012-04-12

    software in which polygon meshes, accurate freeform, non-uniform rationale B-spline surfaces, and geometrically accurate solid models were created...position for a laser scan using a novel morphometric analysis for orthognathic surgery. Int J Oral Max Surg 2000; 29(2): 86-90. Vig PS, Showfety KJ

  6. 3D Printing of Tissue Engineered Constructs for In Vitro Modeling of Disease Progression and Drug Screening.

    PubMed

    Vanderburgh, Joseph; Sterling, Julie A; Guelcher, Scott A

    2017-01-01

    2D cell culture and preclinical animal models have traditionally been implemented for investigating the underlying cellular mechanisms of human disease progression. However, the increasing significance of 3D vs. 2D cell culture has initiated a new era in cell culture research in which 3D in vitro models are emerging as a bridge between traditional 2D cell culture and in vivo animal models. Additive manufacturing (AM, also known as 3D printing), defined as the layer-by-layer fabrication of parts directed by digital information from a 3D computer-aided design file, offers the advantages of simultaneous rapid prototyping and biofunctionalization as well as the precise placement of cells and extracellular matrix with high resolution. In this review, we highlight recent advances in 3D printing of tissue engineered constructs that recapitulate the physical and cellular properties of the tissue microenvironment for investigating mechanisms of disease progression and for screening drugs.

  7. Axes of resistance for tooth movement: does the center of resistance exist in 3-dimensional space?

    PubMed

    Viecilli, Rodrigo F; Budiman, Amanda; Burstone, Charles J

    2013-02-01

    The center of resistance is considered the most important reference point for tooth movement. It is often stated that forces through this point will result in tooth translation. The purpose of this article is to report the results of numeric experiments testing the hypothesis that centers of resistance do not exist in space as 3-dimensional points, primarily because of the geometric asymmetry of the periodontal ligament. As an alternative theory, we propose that, for an arbitrary tooth, translation references can be determined by 2-dimensional projection intersections of 3-dimensional axes of resistance. Finite element analyses were conducted on a maxillary first molar model to determine the position of the axes of rotation generated by 3-dimensional couples. Translation tests were performed to compare tooth movement by using different combinations of axes of resistance as references. The couple-generated axes of rotation did not intersect in 3 dimensions; therefore, they do not determine a 3-dimensional center of resistance. Translation was obtained by using projection intersections of the 2 axes of resistance perpendicular to the force direction. Three-dimensional axes of resistance, or their 2-dimensional projection intersections, should be used to plan movement of an arbitrary tooth. Clinical approximations to a small 3-dimensional "center of resistance volume" might be adequate in nearly symmetric periodontal ligament cases. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  8. Medical 3-D Printing.

    PubMed

    Furlow, Bryant

    2017-05-01

    Three-dimensional printing is used in the manufacturing industry, medical and pharmaceutical research, drug production, clinical medicine, and dentistry, with implications for precision and personalized medicine. This technology is advancing the development of patient-specific prosthetics, stents, splints, and fixation devices and is changing medical education, treatment decision making, and surgical planning. Diagnostic imaging modalities play a fundamental role in the creation of 3-D printed models. Although most 3-D printed objects are rigid, flexible soft-tissue-like prosthetics also can be produced. ©2017 American Society of Radiologic Technologists.

  9. 3D-printed haptic "reverse" models for preoperative planning in soft tissue reconstruction: a case report.

    PubMed

    Chae, Michael P; Lin, Frank; Spychal, Robert T; Hunter-Smith, David J; Rozen, Warren Matthew

    2015-02-01

    In reconstructive surgery, preoperative planning is essential for optimal functional and aesthetic outcome. Creating a three-dimensional (3D) model from two-dimensional (2D) imaging data by rapid prototyping has been used in industrial design for decades but has only recently been introduced for medical application. 3D printing is one such technique that is fast, convenient, and relatively affordable. In this report, we present a case in which a reproducible method for producing a 3D-printed "reverse model" representing a skin wound defect was used for flap design and harvesting. This comprised a 82-year-old man with an exposed ankle prosthesis after serial soft tissue debridements for wound infection. Soft tissue coverage and dead-space filling were planned with a composite radial forearm free flap (RFFF). Computed tomographic angiography (CTA) of the donor site (left forearm), recipient site (right ankle), and the left ankle was performed. 2D data from the CTA was 3D-reconstructed using computer software, with a 3D image of the left ankle used as a "control." A 3D model was created by superimposing the left and right ankle images, to create a "reverse image" of the defect, and printed using a 3D printer. The RFFF was thus planned and executed effectively, without complication. To our knowledge, this is the first report of a mechanism of calculating a soft tissue wound defect and producing a 3D model that may be useful for surgical planning. 3D printing and particularly "reverse" modeling may be versatile options in reconstructive planning, and have the potential for broad application.

  10. Fused Deposition Modeling 3D Printing for (Bio)analytical Device Fabrication: Procedures, Materials, and Applications.

    PubMed

    Salentijn, Gert Ij; Oomen, Pieter E; Grajewski, Maciej; Verpoorte, Elisabeth

    2017-07-05

    In this work, the use of fused deposition modeling (FDM) in a (bio)analytical/lab-on-a-chip research laboratory is described. First, the specifications of this 3D printing method that are important for the fabrication of (micro)devices were characterized for a benchtop FDM 3D printer. These include resolution, surface roughness, leakage, transparency, material deformation, and the possibilities for integration of other materials. Next, the autofluorescence, solvent compatibility, and biocompatibility of 12 representative FDM materials were tested and evaluated. Finally, we demonstrate the feasibility of FDM in a number of important applications. In particular, we consider the fabrication of fluidic channels, masters for polymer replication, and tools for the production of paper microfluidic devices. This work thus provides a guideline for (i) the use of FDM technology by addressing its possibilities and current limitations, (ii) material selection for FDM, based on solvent compatibility and biocompatibility, and (iii) application of FDM technology to (bio)analytical research by demonstrating a broad range of illustrative examples.

  11. Fused Deposition Modeling 3D Printing for (Bio)analytical Device Fabrication: Procedures, Materials, and Applications

    PubMed Central

    2017-01-01

    In this work, the use of fused deposition modeling (FDM) in a (bio)analytical/lab-on-a-chip research laboratory is described. First, the specifications of this 3D printing method that are important for the fabrication of (micro)devices were characterized for a benchtop FDM 3D printer. These include resolution, surface roughness, leakage, transparency, material deformation, and the possibilities for integration of other materials. Next, the autofluorescence, solvent compatibility, and biocompatibility of 12 representative FDM materials were tested and evaluated. Finally, we demonstrate the feasibility of FDM in a number of important applications. In particular, we consider the fabrication of fluidic channels, masters for polymer replication, and tools for the production of paper microfluidic devices. This work thus provides a guideline for (i) the use of FDM technology by addressing its possibilities and current limitations, (ii) material selection for FDM, based on solvent compatibility and biocompatibility, and (iii) application of FDM technology to (bio)analytical research by demonstrating a broad range of illustrative examples. PMID:28628294

  12. Advanced 3-dimensional planning in neurosurgery.

    PubMed

    Ferroli, Paolo; Tringali, Giovanni; Acerbi, Francesco; Schiariti, Marco; Broggi, Morgan; Aquino, Domenico; Broggi, Giovanni

    2013-01-01

    During the past decades, medical applications of virtual reality technology have been developing rapidly, ranging from a research curiosity to a commercially and clinically important area of medical informatics and technology. With the aid of new technologies, the user is able to process large amounts of data sets to create accurate and almost realistic reconstructions of anatomic structures and related pathologies. As a result, a 3-diensional (3-D) representation is obtained, and surgeons can explore the brain for planning or training. Further improvement such as a feedback system increases the interaction between users and models by creating a virtual environment. Its use for advanced 3-D planning in neurosurgery is described. Different systems of medical image volume rendering have been used and analyzed for advanced 3-D planning: 1 is a commercial "ready-to-go" system (Dextroscope, Bracco, Volume Interaction, Singapore), whereas the others are open-source-based software (3-D Slicer, FSL, and FreesSurfer). Different neurosurgeons at our institution experienced how advanced 3-D planning before surgery allowed them to facilitate and increase their understanding of the complex anatomic and pathological relationships of the lesion. They all agreed that the preoperative experience of virtually planning the approach was helpful during the operative procedure. Virtual reality for advanced 3-D planning in neurosurgery has achieved considerable realism as a result of the available processing power of modern computers. Although it has been found useful to facilitate the understanding of complex anatomic relationships, further effort is needed to increase the quality of the interaction between the user and the model.

  13. A 3-Dimensional Atlas of Human Tongue Muscles

    PubMed Central

    SANDERS, IRA; MU, LIANCAI

    2013-01-01

    The human tongue is one of the most important yet least understood structures of the body. One reason for the relative lack of research on the human tongue is its complex anatomy. This is a real barrier to investigators as there are few anatomical resources in the literature that show this complex anatomy clearly. As a result, the diagnosis and treatment of tongue disorders lags behind that for other structures of the head and neck. This report intended to fill this gap by displaying the tongue’s anatomy in multiple ways. The primary material used in this study was serial axial images of the male and female human tongue from the Visible Human (VH) Project of the National Library of Medicine. In addition, thick serial coronal sections of three human tongues were rendered translucent. The VH axial images were computer reconstructed into serial coronal sections and each tongue muscle was outlined. These outlines were used to construct a 3-dimensional computer model of the tongue that allows each muscle to be seen in its in vivo anatomical position. The thick coronal sections supplement the 3-D model by showing details of the complex interweaving of tongue muscles throughout the tongue. The graphics are perhaps the clearest guide to date to aid clinical or basic science investigators in identifying each tongue muscle in any part of the human tongue. PMID:23650264

  14. Invasive 3-Dimensional Organotypic Neoplasia from Multiple Normal Human Epithelia

    PubMed Central

    Ridky, Todd W.; Chow, Jennifer M.; Wong, David J.; Khavari, Paul A.

    2013-01-01

    Refined cancer models are required to assess the burgeoning number of potential targets for cancer therapeutics within a rapid and clinically relevant context. Here we utilize tumor-associated genetic pathways to transform primary human epithelial cells from epidermis, oropharynx, esophagus, and cervix into genetically defined tumors within a human 3-dimensional (3-D) tissue environment incorporating cell-populated stroma and intact basement membrane. These engineered organotypic tissues recapitulated natural features of tumor progression, including epithelial invasion through basement membrane, a complex process critically required for biologic malignancy in 90% of human cancers. Invasion was rapid, and potentiated by stromal cells. Oncogenic signals in 3-D tissue, but not 2-D culture, resembled gene expression profiles from spontaneous human cancers. Screening well-characterized signaling pathway inhibitors in 3-D organotypic neoplasia helped distil a clinically faithful cancer gene signature. Multi-tissue 3-D human tissue cancer models may provide an efficient and relevant complement to current approaches to characterize cancer progression. PMID:21102459

  15. Printed electronics

    NASA Technical Reports Server (NTRS)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel A. (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2012-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  16. Printed Electronics

    NASA Technical Reports Server (NTRS)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2015-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  17. Printed Electronics

    NASA Technical Reports Server (NTRS)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel A. (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2014-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  18. Printed Electronics

    NASA Technical Reports Server (NTRS)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2016-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  19. Face Prints.

    ERIC Educational Resources Information Center

    Hadash, Dre Ann

    1984-01-01

    Eighth graders made prints of their own faces, using photographic papers and chemicals. Describes the supplies needed and the printing process involved. Because junior high school students are so concerned with self, this was a very meaningful activity for them. (CS)

  20. Digital printing

    NASA Astrophysics Data System (ADS)

    Sobotka, Werner K.

    1997-02-01

    Digital printing is described as a tool to replace conventional printing machines completely. Still this goal was not reached until now with any of the digital printing technologies to be described in the paper. Productivity and costs are still the main parameters and are not really solved until now. Quality in digital printing is no problem anymore. Definition of digital printing is to transfer digital datas directly on the paper surface. This step can be carried out directly or with the use of an intermediate image carrier. Keywords in digital printing are: computer- to-press; erasable image carrier; image carrier with memory. Digital printing is also the logical development of the new digital area as it is pointed out in Nicholas Negropotes book 'Being Digital' and also the answer to networking and Internet technologies. Creating images text and color in one country and publishing the datas in another country or continent is the main advantage. Printing on demand another big advantage and last but not least personalization the last big advantage. Costs and being able to coop with this new world of prepress technology is the biggest disadvantage. Therefore the very optimistic growth rates for the next few years are really nonexistent. The development of complete new markets is too slow and the replacing of old markets is too small.

  1. A Seafloor Benchmark for 3-dimensional Geodesy

    NASA Astrophysics Data System (ADS)

    Chadwell, C. D.; Webb, S. C.; Nooner, S. L.

    2014-12-01

    We have developed an inexpensive, permanent seafloor benchmark to increase the longevity of seafloor geodetic measurements. The benchmark provides a physical tie to the sea floor lasting for decades (perhaps longer) on which geodetic sensors can be repeatedly placed and removed with millimeter resolution. Global coordinates estimated with seafloor geodetic techniques will remain attached to the benchmark allowing for the interchange of sensors as they fail or become obsolete, or for the sensors to be removed and used elsewhere, all the while maintaining a coherent series of positions referenced to the benchmark. The benchmark has been designed to free fall from the sea surface with transponders attached. The transponder can be recalled via an acoustic command sent from the surface to release from the benchmark and freely float to the sea surface for recovery. The duration of the sensor attachment to the benchmark will last from a few days to a few years depending on the specific needs of the experiment. The recovered sensors are then available to be reused at other locations, or again at the same site in the future. Three pins on the sensor frame mate precisely and unambiguously with three grooves on the benchmark. To reoccupy a benchmark a Remotely Operated Vehicle (ROV) uses its manipulator arm to place the sensor pins into the benchmark grooves. In June 2014 we deployed four benchmarks offshore central Oregon. We used the ROV Jason to successfully demonstrate the removal and replacement of packages onto the benchmark. We will show the benchmark design and its operational capabilities. Presently models of megathrust slip within the Cascadia Subduction Zone (CSZ) are mostly constrained by the sub-aerial GPS vectors from the Plate Boundary Observatory, a part of Earthscope. More long-lived seafloor geodetic measures are needed to better understand the earthquake and tsunami risk associated with a large rupture of the thrust fault within the Cascadia subduction zone

  2. Prediction of the perceived quality of streak distortions in offset-printing with a psychophysically motivated multi-channel model

    NASA Astrophysics Data System (ADS)

    Gadzicki, Konrad; Zetzsche, Christoph

    2013-08-01

    The evaluation of printing machines poses the problem of how distortions like streaks caused by the machine can be detected and assessed automatically. Although luminance variations in prints can be measured quite precisely, the measured functions bear little relevance for the lightness of streaks and other distortions of prints as perceived by human observers. First, the measurements sometimes indicate changes of luminance in regions which are perceived as homogeneous by humans. Second, the measured strength of a distortion correlates often weakly with its perceived strength, which is influenced by a variety of factors, like the shape of a streak's luminance profile and the distribution of luminance variations in its spatial surround. We have used a model of human perception, based on fundamental neurophysiological and psychophysical properties of the visual system, in order to predict the perceptual strength of streaks (i.e. the distortion as perceived by a human observer) from the measured physical luminance signal. For the evaluation of the model, tests with naive and expert observers have been conducted. The results show that the model yields a good correlation (?) to the assessments of human observers and is thus well suited for use in an automatic evaluation system.

  3. Modeling and Optimization of Printed Spiral Coils in Air, Saline, and Muscle Tissue Environments

    PubMed Central

    Jow, Uei-Ming

    2009-01-01

    Printed spiral coils (PSC) are viable candidates for near field wireless power transmission to the next generation of high performance neuroprosthetic devices with extreme size constraints, which will target intra-ocular and intracranial spaces. Optimizing the PSC geometries to maximize the power transfer efficiency of the wireless link is imperative to reduce the size of the external energy source, heating of the tissue, and interference with other devices. Implantable devices need to be hermetically sealed in biocompatible materials and placed in a conductive environment with high permittivity (tissue), which can affect the PSC characteristics. We have constructed a detailed model that includes the effects of the surrounding environment on the PSC parasitic components and eventually on the power transfer efficiency. We have combined this model with an iterative design method that starts with a set of realistic design constraints and ends with the optimal PSC geometries. We applied our design methodology to optimize the wireless link of a 1 cm2 implantable device example, operating at 13.56 MHz. Measurement results showed that optimized PSC pairs, coated with 0.3 mm of silicone, achieved 72.2%, 51.8%, and 30.8% efficiencies at a face to face relative distance of 10 mm, in air, saline, and muscle, respectively. The PSC which was optimized for air could only bear 40.8% and 21.8% efficiencies in saline and muscle, respectively, showing that including the PSC tissue environment in the design process can result in more than 9% improvement in the power transfer efficiency. PMID:19964693

  4. Modeling and Optimization of Printed Spiral Coils in Air, Saline, and Muscle Tissue Environments

    PubMed Central

    Jow, Uei-Ming; Ghovanloo, Maysam

    2010-01-01

    Printed spiral coils (PSCs) are viable candidates for near-field wireless power transmission to the next generation of high-performance neuroprosthetic devices with extreme size constraints, which will target intraocular and intracranial spaces. Optimizing the PSC geometries to maximize the power transfer efficiency of the wireless link is imperative to reduce the size of the external energy source, heating of the tissue, and interference with other devices. Implantable devices need to be hermetically sealed in biocompatible materials and placed in a conductive environment with high permittivity (tissue), which can affect the PSC characteristics. We have constructed a detailed model that includes the effects of the surrounding environment on the PSC parasitic components and eventually on the power transfer efficiency. We have combined this model with an iterative design method that starts with a set of realistic design constraints and ends with the optimal PSC geometries. We applied our design methodology to optimize the wireless link of a 1-cm2 implantable device example, operating at 13.56 MHz. Measurement results showed that optimized PSC pairs, coated with 0.3 mm of silicone, achieved 72.2%, 51.8%, and 30.8% efficiencies at a face-to-face relative distance of 10 mm in air, saline, and muscle, respectively. The PSC, which was optimized for air, could only bear 40.8% and 21.8% efficiencies in saline and muscle, respectively, showing that by including the PSC tissue environment in the design process the result can be more than a 9% improvement in the power transfer efficiency. PMID:20948991

  5. Direct-Write Printing on Three-Dimensional Geometries for Miniaturized Detector and Electronic Assemblies

    NASA Technical Reports Server (NTRS)

    Paquette, Beth; Samuels, Margaret; Chen, Peng

    2017-01-01

    Direct-write printing techniques will enable new detector assemblies that were not previously possible with traditional assembly processes. Detector concepts were manufactured using this technology to validate repeatability. Additional detector applications and printed wires on a 3-dimensional magnetometer bobbin will be designed for print. This effort focuses on evaluating performance for direct-write manufacturing techniques on 3-dimensional surfaces. Direct-write manufacturing has the potential to reduce mass and volume for fabrication and assembly of advanced detector concepts by reducing trace widths down to 10 microns, printing on complex geometries, allowing new electronic concept production, and reduced production times of complex those electronics.

  6. Comparison of 2-Dimensional and 3-Dimensional Metacarpal Fracture Plating Constructs Under Cyclic Loading.

    PubMed

    Tannenbaum, Eric P; Burns, Geoffrey T; Oak, Nikhil R; Lawton, Jeffrey N

    2017-03-01

    Metacarpal fractures are commonly treated by a variety of means including casting or open reduction internal fixation when unacceptable alignment is present following attempted closed reduction. Dorsal plating with either single-row 2-dimensional or double-row 3-dimensional plates has been proposed. This study's purpose was to determine if there are any differences in fixation construct stability under cyclic loading and subsequent load to failure between the lower profile 3-dimensional and the larger 2-dimensional plates in a metacarpal fracture gap sawbone model. Thirty metacarpal cortico-cancellous synthetic bones were cut with a 1.75-mm gap between the 2 fragments simulating mid-diaphyseal fracture comminution. Half of the metacarpals were plated with 2.0-mm locking 2-dimensional plates and half with 1.5-mm locking 3-dimensional plates. The plated metacarpals were mounted into a materials testing apparatus and cyclically loaded under cantilever bending for 2,000 cycles at 70 N, then 2,000 cycles at 120 N, and finally monotonically loaded to failure. Throughout testing, fracture gap sizes were measured, failure modes were recorded, and construct strength and stiffness values were calculated. All 3-dimensional constructs survived both cyclic loading conditions. Ten (67%) 2-dimensional constructs survived both loading conditions, whereas 5 (33%) failed the 120-N loading at 1377 ± 363 cycles. When loaded to failure, the 3-dimensional constructs failed at 265 N ± 21 N, whereas the 2-dimensional constructs surviving cyclic loading failed at 190 N ± 17 N. The shorter, thinner 3-dimensional metacarpal plates demonstrated increased resistance to failure in a cyclic loading model and increased load to failure compared with the relatively longer, thicker 2-dimensional metacarpal plates. The lower-profile 3-dimensional metacarpal plate fixation demonstrated greater stability for early postoperative resistance than the thicker 2-dimensional fixation, whereas the smaller

  7. Quantitative 3-dimensional computed tomography measurements of coronoid fractures.

    PubMed

    Mellema, Jos J; Janssen, Stein J; Guitton, Thierry G; Ring, David

    2015-03-01

    Using quantitative 3-dimensional computed tomography (Q3DCT) modeling, we tested the null hypothesis that there was no difference in fracture fragment volume, articular surface involvement, and number of fracture fragments between coronoid fracture types and patterns of traumatic elbow instability. We studied 82 patients with a computed tomography scan of a coronoid fracture using Q3DCT modeling. Fracture fragments were identified and fragment volume and articular surface involvement were measured within fracture types and injury patterns. Kruskal-Wallis test was used to evaluate the Q3DCT data of the coronoid fractures. Fractures of the coronoid tip (n = 45) were less fragmented and had the smallest fragment volume and articular surface area involvement compared with anteromedial facet fractures (n = 20) and base fractures (n = 17). Anteromedial facet and base fractures were more fragmented than tip fractures, and base fractures had the largest fragment volume and articular surface area involvement compared with tip and anteromedial facet fractures. We found similar differences between fracture types described by Regan and Morrey. Furthermore, fractures associated with terrible triad fracture dislocation (n = 42) had the smallest fragment volume, and fractures associated with olecranon fracture dislocations (n = 17) had the largest fragment volume and articular surface area involvement compared with the other injury patterns. Analyzing fractures of the coronoid using Q3DCT modeling demonstrated that fracture fragment characteristics differ significantly between fracture types and injury patterns. Detailed knowledge of fracture characteristics and their association with specific patterns of traumatic elbow instability may assist decision making and preoperative planning. Quantitative 3DCT modeling can provide a more detailed understanding of fracture morphology, which might guide decision making and implant development. Copyright © 2015 American Society for

  8. Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine.

    PubMed

    O'Reilly, Michael K; Reese, Sven; Herlihy, Therese; Geoghegan, Tony; Cantwell, Colin P; Feeney, Robin N M; Jones, James F X

    2016-01-01

    For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century.

  9. A neurosurgical simulation of skull base tumors using a 3D printed rapid prototyping model containing mesh structures.

    PubMed

    Kondo, Kosuke; Harada, Naoyuki; Masuda, Hiroyuki; Sugo, Nobuo; Terazono, Sayaka; Okonogi, Shinichi; Sakaeyama, Yuki; Fuchinoue, Yutaka; Ando, Syunpei; Fukushima, Daisuke; Nomoto, Jun; Nemoto, Masaaki

    2016-06-01

    Deep regions are not visible in three-dimensional (3D) printed rapid prototyping (RP) models prepared from opaque materials, which is not the case with translucent images. The objectives of this study were to develop an RP model in which a skull base tumor was simulated using mesh, and to investigate its usefulness for surgical simulations by evaluating the visibility of its deep regions. A 3D printer that employs binder jetting and is mainly used to prepare plaster models was used. RP models containing a solid tumor, no tumor, and a mesh tumor were prepared based on computed tomography, magnetic resonance imaging, and angiographic data for four cases of petroclival tumor. Twelve neurosurgeons graded the three types of RP model into the following four categories: 'clearly visible,' 'visible,' 'difficult to see,' and 'invisible,' based on the visibility of the internal carotid artery, basilar artery, and brain stem through a craniotomy performed via the combined transpetrosal approach. In addition, the 3D positional relationships between these structures and the tumor were assessed. The internal carotid artery, basilar artery, and brain stem and the positional relationships of these structures with the tumor were significantly more visible in the RP models with mesh tumors than in the RP models with solid or no tumors. The deep regions of PR models containing mesh skull base tumors were easy to visualize. This 3D printing-based method might be applicable to various surgical simulations.

  10. New Roles and Training Models for Managers in the Printing and Communications Industry in the Netherlands.

    ERIC Educational Resources Information Center

    Nijhof, Wim J.; Streumer, Jan N.

    1998-01-01

    Interviews in five Dutch printing/communications firms, survey responses from 462 of 1069 managers, and a DACUM (Developing a Curriculum) process identified technical changes, skill needs, and management tasks in the industry. A new structure was developed for training managers in these roles: producer, innovator, motivator, administrator,…

  11. The Application of Three-Dimensional Printing in Animal Model of Augmentation Rhinoplasty.

    PubMed

    Kim, Yoo Suk; Shin, Yoo Seob; Park, Do Yang; Choi, Jae Won; Park, Joo Kyung; Kim, Dong Ho; Kim, Chul Ho; Park, Su A

    2015-09-01

    The role of three-dimensional (3D) printing has expanded in diverse areas in medicine. As plastic surgery needs to fulfill the different demands from diverse individuals, the applications of tailored 3D printing will become indispensable. In this study, we evaluated the feasibility of using 3D-printed polycaprolactone (PCL) scaffold seeded with fibrin/chondrocytes as a new dorsal augmentation material for rhinoplasty. The construct was surgically implanted on the nasal dorsum in the subperiosteal plane of six rabbits. The implants were harvested 4 and 12 weeks after implantation and evaluated by gross morphological assessment, radiographic imaging, and histologic examination. The initial shape of the implant was unchanged in all cases, and no definite post-operative complications were seen over the 3-month period. Radiologic evaluation confirmed that implants remained in the initial location without migration or extrusion. Histologic evaluations showed that the scaffold architectures were maintained with minimal inflammatory reactions; however, expected neo-chondrogenesis was not definite in the constructs. A new PCL scaffold designed by 3D printing method seeded with fibrin/chondrocytes can be a biocompatible augmentation material in rhinoplasty in the future.

  12. Molecular printing

    PubMed Central

    Braunschweig, Adam B.; Huo, Fengwei; Mirkin, Chad A.

    2014-01-01

    Molecular printing techniques, which involve the direct transfer of molecules to a substrate with submicrometre resolution, have been extensively developed over the past decade and have enabled many applications. Arrays of features on this scale have been used to direct materials assembly, in nanoelectronics, and as tools for genetic analysis and disease detection. The past decade has witnessed the maturation of molecular printing led by two synergistic technologies: dip-pen nanolithography and soft lithography. Both are characterized by material and substrate flexibility, but dip-pen nanolithography has unlimited pattern design whereas soft lithography has limited pattern flexibility but is low in cost and has high throughput. Advances in DPN tip arrays and inking methods have increased the throughput and enabled applications such as multiplexed arrays. A new approach to molecular printing, polymer-pen lithography, achieves low-cost, high-throughput and pattern flexibility. This Perspective discusses the evolution and future directions of molecular printing. PMID:21378889

  13. 3-Dimensional wireless sensor network localization: A review

    NASA Astrophysics Data System (ADS)

    Najib, Yasmeen Nadhirah Ahmad; Daud, Hanita; Aziz, Azrina Abd; Razali, Radzuan

    2016-11-01

    The proliferation of wireless sensor network (WSN) has shifted the focus to 3-Dimensional geometry rather than 2-Dimensional geometry. Since exact location of sensors has been the fundamental issue in wireless sensor network, node localization is essential for any wireless sensor network applications. Most algorithms mainly focus on 2-Dimensional geometry, where the application of this algorithm will decrease the accuracy on 3-Dimensional geometry. The low rank attribute in WSN's node estimation makes the application of nuclear norm minimization as a viable solution for dimensionality reduction problems. This research proposes a novel localization algorithm for 3-Dimensional WSN which is nuclear norm minimization. The node localization is formulated via Euclidean Distance Matrix (EDM) and is then optimized using Nuclear-Norm Minimization (NNM).

  14. Hot-melt extruded filaments based on pharmaceutical grade polymers for 3D printing by fused deposition modeling.

    PubMed

    Melocchi, Alice; Parietti, Federico; Maroni, Alessandra; Foppoli, Anastasia; Gazzaniga, Andrea; Zema, Lucia

    2016-07-25

    Fused deposition modeling (FDM) is a 3D printing technique based on the deposition of successive layers of thermoplastic materials following their softening/melting. Such a technique holds huge potential for the manufacturing of pharmaceutical products and is currently under extensive investigation. Challenges in this field are mainly related to the paucity of adequate filaments composed of pharmaceutical grade materials, which are needed for feeding the FDM equipment. Accordingly, a number of polymers of common use in pharmaceutical formulation were evaluated as starting materials for fabrication via hot melt extrusion of filaments suitable for FDM processes. By using a twin-screw extruder, filaments based on insoluble (ethylcellulose, Eudragit(®) RL), promptly soluble (polyethylene oxide, Kollicoat(®) IR), enteric soluble (Eudragit(®) L, hydroxypropyl methylcellulose acetate succinate) and swellable/erodible (hydrophilic cellulose derivatives, polyvinyl alcohol, Soluplus(®)) polymers were successfully produced, and the possibility of employing them for printing 600μm thick disks was demonstrated. The behavior of disks as barriers when in contact with aqueous fluids was shown consistent with the functional application of the relevant polymeric components. The produced filaments were thus considered potentially suitable for printing capsules and coating layers for immediate or modified release, and, when loaded with active ingredients, any type of dosage forms.

  15. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    NASA Astrophysics Data System (ADS)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-07-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed.

  16. Fabrication of extended-release patient-tailored prednisolone tablets via fused deposition modelling (FDM) 3D printing.

    PubMed

    Skowyra, Justyna; Pietrzak, Katarzyna; Alhnan, Mohamed A

    2015-02-20

    Rapid and reliable tailoring of the dose of controlled release tablets to suit an individual patient is a major challenge for personalized medicine. The aim of this work was to investigate the feasibility of using a fused deposition modelling (FDM) based 3D printer to fabricate extended release tablet using prednisolone loaded poly(vinyl alcohol) (PVA) filaments and to control its dose. Prednisolone was loaded into a PVA-based (1.75 mm) filament at approximately 1.9% w/w via incubation in a saturated methanolic solution of prednisolone. The physical form of the drug was assessed using differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Dose accuracy and in vitro drug release patterns were assessed using HPLC and pH change flow-through dissolution test. Prednisolone loaded PVA filament demonstrated an ability to be fabricated into regular ellipse-shaped solid tablets using the FDM-based 3D printer. It was possible to control the mass of printed tablet through manipulating the volume of the design (R(2) = 0.9983). On printing tablets with target drug contents of 2, 3, 4, 5, 7.5 and 10mg, a good correlation between target and achieved dose was obtained (R(2) = 0.9904) with a dose accuracy range of 88.7-107%. Thermal analysis and XRPD indicated that the majority of prednisolone existed in amorphous form within the tablets. In vitro drug release from 3D printed tablets was extended up to 24h. FDM based 3D printing is a promising method to produce and control the dose of extended release tablets, providing a highly adjustable, affordable, minimally sized, digitally controlled platform for producing patient-tailored medicines. Copyright © 2015. Published by Elsevier B.V.

  17. Thoracoscopic anatomical subsegmentectomy of the right S2b + S3 using a 3D printing model with rapid prototyping.

    PubMed

    Nakada, Takeo; Akiba, Tadashi; Inagaki, Takuya; Morikawa, Toshiaki

    2014-10-01

    Thoracoscopic segmentectomies and subsegmentectomies are more difficult than lobectomy because of the complexity of the procedure; therefore, preoperative decision-making and surgical procedure planning are essential. In the literature, we could successfully perform thoracoscopic anatomical subsegmentectomy of the right S2b + S3 using a 3D printing model with rapid prototyping. This innovative surgical support model is extremely useful for planning a surgical procedure and identifying the surgical margin. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  18. The radiological feature of anterior occiput-to-axis screw fixation as it guides the screw trajectory on 3D printed models: a feasibility study on 3D images and 3D printed models.

    PubMed

    Wu, Ai-Min; Wang, Sheng; Weng, Wan-Qing; Shao, Zhen-Xuan; Yang, Xin-Dong; Wang, Jian-Shun; Xu, Hua-Zi; Chi, Yong-Long

    2014-12-01

    Anterior occiput-to-axis screw fixation is more suitable than a posterior approach for some patients with a history of posterior surgery. The complex osseous anatomy between the occiput and the axis causes a high risk of injury to neurological and vascular structures, and it is important to have an accurate screw trajectory to guide anterior occiput-to-axis screw fixation. Thirty computed tomography (CT) scans of upper cervical spines were obtained for three-dimensional (3D) reconstruction. Cylinders (1.75 mm radius) were drawn to simulate the trajectory of an anterior occiput-to-axis screw. The imitation screw was adjusted to 4 different angles and measured, as were the values of the maximized anteroposterior width and the left-right width of the occiput (C0) to the C1 and C1 to C2 joints. Then, the 3D models were printed, and an angle guide device was used to introduce the screws into the 3D models referring to the angles calculated from the 3D images. We found the screw angle ranged from α1 (left: 4.99±4.59°; right: 4.28±5.45°) to α2 (left: 20.22±3.61°; right: 19.63±4.94°); on the lateral view, the screw angle ranged from β1 (left: 13.13±4.93°; right: 11.82±5.64°) to β2 (left: 34.86±6.00°; right: 35.01±5.77°). No statistically significant difference was found between the data of the left and right sides. On the 3D printed models, all of the anterior occiput-to-axis screws were successfully introduced, and none of them penetrated outside of the cortex; the mean α4 was 12.00±4.11 (left) and 12.25±4.05 (right), and the mean β4 was 23.44±4.21 (left) and 22.75±4.41 (right). No significant difference was found between α4 and β4 on the 3D printed models and α3 and β3 calculated from the 3D digital images of the left and right sides. Aided with the angle guide device, we could achieve an optimal screw trajectory for anterior occiput-to-axis screw fixation on 3D printed C0 to C2 models.

  19. 3D heart model printing for preparation of percutaneous structural interventions: description of the technology and case report.

    PubMed

    Dankowski, Rafał; Baszko, Artur; Sutherland, Michael; Firek, Ludwik; Kałmucki, Piotr; Wróblewska, Katarzyna; Szyszka, Andrzej; Groothuis, Adam; Siminiak, Tomasz

    2014-01-01

    Structural heart disease, including valvular disease as well as congenital defects, causes important alterations in heart anatomy. As a result, individualised planning for both surgical and percutaneous procedures is crucial for procedural optimisation. Three dimensional (3D) rapid prototyping techniques are being utilised to aid operators in planning structural heart procedures. We intend to provide a description of 3D printing as a clinically applicable heart modelling technology for the planning of percutaneous structural heart procedures as well as to report our first clinical use of a 3D printed patient-specific heart model in preparation for a percutaneous mitral annuloplasty using the Mitralign percutaneous annuloplasty system. Retrospectively gated, contrast enhanced, multi-slice computed tomography (MSCT) scans were obtained. MSCT DICOM data was analysed using software that creates 3D surface files of the blood volume of specific regions of interest in the heart. The surface files are rendered using a software package that creates a solid model that can be printed using commercially available stereolithography machines. The technique of direct percutaneous mitral annuloplasty requires advancement of a guiding catheter through the aorta, into the left ventricle, and requires the positioning of the tip of the catheter between the papillary muscles in close proximity to the mitral annulus. The 3D heart model was used to create a procedural plan to optimise potential device implantation. The size of the deflectable guiding catheter was selected on the basis of the patient's heart model. Target locations for annulus crossing wires were evaluated pre-procedurally using the individual patient's 3D heart model. In addition, the ability to position the Bident Catheter at the appropriate locations under the mitral annulus as well as the manoeuvrability between the papillary muscles were analysed on the heart model, enabling safe completion of the procedure, which

  20. Accuracy and efficiency of full-arch digitalization and 3D printing: A comparison between desktop model scanners, an intraoral scanner, a CBCT model scan, and stereolithographic 3D printing.

    PubMed

    Wesemann, Christian; Muallah, Jonas; Mah, James; Bumann, Axel

    2017-01-01

    The primary objective of this study was to compare the accuracy and time efficiency of an indirect and direct digitalization workflow with that of a three-dimensional (3D) printer in order to identify the most suitable method for orthodontic use. A master model was measured with a coordinate measuring instrument. The distances measured were the intercanine width, the intermolar width, and the dental arch length. Sixty-four scans were taken with each of the desktop scanners R900 and R700 (3Shape), the intraoral scanner TRIOS Color Pod (3Shape), and the Promax 3D Mid cone beam computed tomography (CBCT) unit (Planmeca). All scans were measured with measuring software. One scan was selected and printed 37 times on the D35 stereolithographic 3D printer (Innovation MediTech). The printed models were measured again using the coordinate measuring instrument. The most accurate results were obtained by the R900. The R700 and the TRIOS intraoral scanner showed comparable results. CBCT-3D-rendering with the Promax 3D Mid CBCT unit revealed significantly higher accuracy with regard to dental casts than dental impressions. 3D printing offered a significantly higher level of deviation than digitalization with desktop scanners or an intraoral scanner. The chairside time required for digital impressions was 27% longer than for conventional impressions. Conventional impressions, model casting, and optional digitization with desktop scanners remains the recommended workflow process. For orthodontic demands, intraoral scanners are a useful alternative for full-arch scans. For prosthodontic use, the scanning scope should be less than one quadrant and three additional teeth.

  1. Design and Fabrication of Kidney Phantoms for Internal Radiation Dosimetry Using 3D Printing Technology.

    PubMed

    Tran-Gia, Johannes; Schlögl, Susanne; Lassmann, Michael

    2016-12-01

    Currently, the validation of multimodal quantitative imaging and absorbed dose measurements is impeded by the lack of suitable, commercially available anthropomorphic phantoms of variable sizes and shapes. To demonstrate the potential of 3-dimensional (3D) printing techniques for quantitative SPECT/CT imaging, a set of kidney dosimetry phantoms and their spherical counterparts was designed and manufactured with a fused-deposition-modeling 3D printer. Nuclide-dependent SPECT/CT calibration factors were determined to assess the accuracy of quantitative imaging for internal renal dosimetry.

  2. Fused-filament 3D printing of drug products: Microstructure analysis and drug release characteristics of PVA-based caplets.

    PubMed

    Goyanes, Alvaro; Kobayashi, Masanori; Martínez-Pacheco, Ramón; Gaisford, Simon; Basit, Abdul W

    2016-11-30

    Fused deposition modeling (FDM) 3-Dimensional (3D) printing is becoming an increasingly important technology in the pharmaceutical sciences, since it allows the manufacture of personalized oral dosage forms by deposition of thin layers of material. Here, a filament extruder was used to obtain filaments of polyvinyl alcohol (PVA) containing paracetamol or caffeine appropriate for 3D printing. The filaments were used to manufacture caplets for oral administration by FDM 3D printing, with the aim of evaluating the effect of the internal structure (micropore volume), drug loading and composition on drug dissolution behaviour. Micropore volume of the caplets was primarily determined by the presence of large pores due to gaps in the printed layers/net while printing, and the porosity of the caplets was 10 fold higher than the porosity of the extruded filament. Dynamic dissolution drug release tests on the caplets in biorelevant bicarbonate media revealed distinctive release profiles, which were dependent on drug solubility and drug loading. Porosity of the caplets did not help to predict the different drug release profiles. This study confirms the potential of 3D printing to fabricate caplets and helps to elucidate which factors influence drug release from this type of new dosage form.

  3. Printed MDCT 3D models for prediction of Left Atrial Appendage (LAA) occluder device size - A feasibility study.

    PubMed

    Goitein, Orly; Fink, Noam; Guetta, Victor; Beinart, Roy; Brodov, Yafim; Konen, Eli; Goitein, David; Di Segni, Elio; Grupper, Avishay; Glikson, Michael

    2017-05-16

    Trans-esophageal echocardiography (TEE) and MDCT currently serve as imaging modalities for left atrial appendage (LAA) occlusion pre-procedural planning. We assessed the feasibility of multi-detector CT (MDCT) based models to predict the correct size of device for LAA occlusion procedures. Patients planned for LAA occlusion underwent MDCT before implantation, which was used for creating and printing 3D LAA models. Three cardiologists evaluated the 3D models and predicted the correct size of the device by manual manipulation, these predictions were compared with the actual device implanted during the procedure. Twenty nine patients were included in this study. Amplatzer™ and Watchman™ devices were deployed in 12 and 17 patients, respectively. Two procedures were aborted due to failure of occlusion, all three physicians predicted it. There was good correlation between the 3D models and the inserted device for Amplatzer™ devices with concordance correlation coefficient 0.778 (P=0.001) and poor agreement for Watchman™ devices - concordance correlation coefficient of 0.315 (P=0.203). Agreement between the three physicians for Amplatzer ™ and Watchman™ devices were excellent with a calculated average intra-class correlation of 0.915 and 0.816 respectively. We found LAA printed 3D models to be accurate for prediction of LAA occluder device size for Amplatzer™ device but not for Watchman™ device.

  4. The 3-dimensional construction of the Rae craton, central Canada

    NASA Astrophysics Data System (ADS)

    Snyder, David B.; Craven, James A.; Pilkington, Mark; Hillier, Michael J.

    2015-10-01

    Reconstruction of the 3-dimensional tectonic assembly of early continents, first as Archean cratons and then Proterozoic shields, remains poorly understood. In this paper, all readily available geophysical and geochemical data are assembled in a 3-D model with the most accurate bedrock geology in order to understand better the geometry of major structures within the Rae craton of central Canada. Analysis of geophysical observations of gravity and seismic wave speed variations revealed several lithospheric-scale discontinuities in physical properties. Where these discontinuities project upward to correlate with mapped upper crustal geological structures, the discontinuities can be interpreted as shear zones. Radiometric dating of xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences. These ages can also be correlated to surface rocks. The 3.6-2.6 Ga Rae craton comprises at least three smaller continental terranes, which "cratonized" during a granitic bloom. Cratonization probably represents final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho. The peak thermotectonic event at 1.86-1.7 Ga was associated with the Hudsonian orogeny that assembled several cratons and lesser continental blocks into the Canadian Shield using a number of southeast-dipping megathrusts. This orogeny metasomatized, mineralized, and recrystallized mantle and lower crustal rocks, apparently making them more conductive by introducing or concentrating sulfides or graphite. Little evidence exists of thin slabs similar to modern oceanic lithosphere in this Precambrian construction history whereas underthrusting and wedging of continental lithosphere is inferred from multiple dipping discontinuities.

  5. Brain tumor surgery with 3-dimensional surface navigation.

    PubMed

    Mert, Ayguel; Buehler, Katja; Sutherland, Garnette R; Tomanek, Boguslaw; Widhalm, Georg; Kasprian, Gregor; Knosp, Engelbert; Wolfsberger, Stefan

    2012-12-01

    Precise lesion localization is necessary for neurosurgical procedures not only during the operative approach, but also during the preoperative planning phase. To evaluate the advantages of 3-dimensional (3-D) brain surface visualization over conventional 2-dimensional (2-D) magnetic resonance images for surgical planning and intraoperative guidance in brain tumor surgery. Preoperative 3-D brain surface visualization was performed with neurosurgical planning software in 77 cases (58 gliomas, 7 cavernomas, 6 meningiomas, and 6 metastasis). Direct intraoperative navigation on the 3-D brain surface was additionally performed in the last 20 cases with a neurosurgical navigation system. For brain surface reconstruction, patient-specific anatomy was obtained from MR imaging and brain volume was extracted with skull stripping or watershed algorithms, respectively. Three-dimensional visualization was performed by direct volume rendering in both systems. To assess the value of 3-D brain surface visualization for topographic lesion localization, a multiple-choice test was developed. To assess accuracy and reliability of 3-D brain surface visualization for intraoperative orientation, we topographically correlated superficial vessels and gyral anatomy on 3-D brain models with intraoperative images. The rate of correct lesion localization with 3-D was significantly higher (P = .001, χ), while being significantly less time consuming (P < .001, χ) compared with 2-D images. Intraoperatively, visual correlation was found between the 3-D images, superficial vessels, and gyral anatomy. The proposed method of 3-D brain surface visualization is fast, clinically reliable for preoperative anatomic lesion localization and patient-specific planning, and, together with navigation, improves intraoperative orientation in brain tumor surgery and is relatively independent of brain shift.

  6. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    PubMed Central

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  7. Guided Autotransplantation of Teeth: A Novel Method Using Virtually Planned 3-dimensional Templates.

    PubMed

    Strbac, Georg D; Schnappauf, Albrecht; Giannis, Katharina; Bertl, Michael H; Moritz, Andreas; Ulm, Christian

    2016-12-01

    The aim of this study was to introduce an innovative method for autotransplantation of teeth using 3-dimensional (3D) surgical templates for guided osteotomy preparation and donor tooth placement. This report describes autotransplantation of immature premolars as treatment of an 11-year-old boy having suffered severe trauma with avulsion of permanent maxillary incisors. This approach uses modified methods from guided implant surgery by superimposition of Digital Imaging and Communications in Medicine files and 3D data sets of the jaws in order to predesign 3D printed templates with the aid of a fully digital workflow. The intervention in this complex case could successfully be accomplished by performing preplanned virtual transplantations with guided osteotomies to prevent bone loss and ensure accurate donor teeth placement in new recipient sites. Functional and esthetic restoration could be achieved by modifying methods used in guided implant surgery and prosthodontic rehabilitation. The 1-year follow-up showed vital natural teeth with physiological clinical and radiologic parameters. This innovative approach uses the latest diagnostic methods and techniques of guided implant surgery, enabling the planning and production of 3D printed surgical templates. These accurate virtually predesigned surgical templates could facilitate autotransplantation in the future by full implementation of recommended guidelines, ensuring an atraumatic surgical protocol. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Differential Cross Section Kinematics for 3-dimensional Transport Codes

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank

    2008-01-01

    In support of the development of 3-dimensional transport codes, this paper derives the relevant relativistic particle kinematic theory. Formulas are given for invariant, spectral and angular distributions in both the lab (spacecraft) and center of momentum frames, for collisions involving 2, 3 and n - body final states.

  9. Controlled teleportation of a 3-dimensional bipartite quantum state

    NASA Astrophysics Data System (ADS)

    Cao, Hai-Jing; Chen, Zhong-Hua; Song, He-Shan

    2008-07-01

    A controlled teleportation scheme of an unknown 3-dimensional (3D) two-particle quantum state is proposed, where a 3D Bell state and 3D GHZ state function as the quantum channel. This teleportation scheme can be directly generalized to teleport an unknown d-dimensional bipartite quantum state.

  10. Airway growth and development: a computerized 3-dimensional analysis.

    PubMed

    Schendel, Stephen A; Jacobson, Richard; Khalessi, Sadri

    2012-09-01

    The present study was undertaken to investigate the changes in the normal upper airway during growth and development using 3-dimensional computer analysis from cone-beam computed tomography (CBCT) data to provide a normative reference. The airway size and respiratory mode are known to have a relationship to facial morphology and the development of a malocclusion. The use of CBCT, 3-dimensional imaging, and automated computer analysis in treatment planning allows the upper airway to be precisely evaluated. In the present study, we evaluated the growth of the airway using 3-dimensional analysis and CBCT data from age 6 through old age, in 1300 normal individuals. The airway size and length increase until age 20 at which time a variable period of stability occurs. Next, the airway at first decreases slowly in size and then, after age 40, more rapidly. Normative data are provided in the present study for age groups from 6 to 60 years in relation to the airway total volume, smallest cross-sectional area and vertical length of the airway. This 3-dimensional data of the upper airway will provide a normative reference as an aid in the early understanding of respiration and dentofacial anatomy, which will help in early treatment planning. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  11. 3-dimensional bundle adjustments in industrial metrology: A comparison

    SciTech Connect

    Gaydosh, M.; LeCocq, C.; Ruland, R.; Wand, B.

    1992-07-01

    Several theodolite measurement systems are available for use in the industrial metrology market. Many of them offer a rigorous 3-dimensional bundle adjustment routine. In this paper several systems in use and available for evaluation purposes at the Stanford Linear Accelerator Center will be tested and their results compared.

  12. Deformation and fatigue of tough 3D printed elastomer scaffolds processed by fused deposition modeling and continuous liquid interface production.

    PubMed

    Miller, Andrew T; Safranski, David L; Wood, Catherine; Guldberg, Robert E; Gall, Ken

    2017-07-01

    Polyurethane (PU) based elastomers continue to gain popularity in a variety of biomedical applications as compliant implant materials. In parallel, advancements in additive manufacturing continue to provide new opportunities for biomedical applications by enabling the creation of more complex architectures for tissue scaffolding and patient specific implants. The purpose of this study was to examine the effects of printed architecture on the monotonic and cyclic mechanical behavior of elastomeric PUs and to compare the structure-property relationship across two different printing approaches. We examined the tensile fatigue of notched specimens, 3D crosshatch scaffolds, and two 3D spherical pore architectures in a physically crosslinked polycarbonate urethane (PCU) printed via fused deposition modeling (FDM) as well as a photo-cured, chemically-crosslinked, elastomeric PU printed via continuous liquid interface production (CLIP). Both elastomers were relatively tolerant of 3D geometrical features as compared to stiffer synthetic implant materials such as PEEK and titanium. PCU and crosslinked PU samples with 3D porous structures demonstrated a reduced tensile failure stress as expected without a significant effect on tensile failure strain. PCU crosshatch samples demonstrated similar performance in strain-based tensile fatigue as solid controls; however, when plotted against stress amplitude and adjusted by porosity, it was clear that the architecture had an impact on performance. Square shaped notches or pores in crosslinked PU appeared to have a modest effect on strain-based tensile fatigue while circular shaped notches and pores had little impact relative to smooth samples. When plotted against stress amplitude, any differences in fatigue performance were small or not statistically significant for crosslinked PU samples. Despite the slight difference in local architecture and tolerances, crosslinked PU solid samples were found to perform on par with PCU solid

  13. A Molecular Perspective of Inter-filament Bonding in Fused Deposition Modeling 3-D Printing

    NASA Astrophysics Data System (ADS)

    Duranty, Edward; Spradlin, Brandon; Dadmun, Mark

    2015-03-01

    Fused deposition 3D printing is an important tool for low-cost and rapid prototyping of objects with complex geometries. 3D printed materials are composed of many filaments deposited on a heated substrate, requiring the bonding of neighboring filaments during the deposition process. Filament deposition often creates voids between filaments, which requires necking between them to create a robust sample. Therefore the amount of interfacial contact and interdiffusion between filaments become important parameters that control the macroscopic physical properties of the printed prototype. Our research focuses on quantifying the interfacial adhesion between ABS filaments and its impact on structural properties. The time evolution of the temperature profile near the heated substrate demonstrates that the deposited filaments are repeatedly heated above the Tg of ABS allowing interpenetration of the polymer chains between adjacent filaments. Results of DMA experiments on samples of different geometries have been correlated to microphotography that monitors the degree of necking between filaments and the thermal history. Results indicate that interfacial contact area between filaments and increased thermal energy are crucial to their mechanical properties.

  14. A critical evaluation of secondary cancer risk models applied to Monte Carlo dose distributions of 2-dimensional, 3-dimensional conformal and hybrid intensity-modulated radiation therapy for breast cancer

    NASA Astrophysics Data System (ADS)

    Joosten, A.; Bochud, F.; Moeckli, R.

    2014-08-01

    The comparison of radiotherapy techniques regarding secondary cancer risk has yielded contradictory results possibly stemming from the many different approaches used to estimate risk. The purpose of this study was to make a comprehensive evaluation of different available risk models applied to detailed whole-body dose distributions computed by Monte Carlo for various breast radiotherapy techniques including conventional open tangents, 3D conformal wedged tangents and hybrid intensity modulated radiation therapy (IMRT). First, organ-specific linear risk models developed by the International Commission on Radiological Protection (ICRP) and the Biological Effects of Ionizing Radiation (BEIR) VII committee were applied to mean doses for remote organs only and all solid organs. Then, different general non-linear risk models were applied to the whole body dose distribution. Finally, organ-specific non-linear risk models for the lung and breast were used to assess the secondary cancer risk for these two specific organs. A total of 32 different calculated absolute risks resulted in a broad range of values (between 0.1% and 48.5%) underlying the large uncertainties in absolute risk calculation. The ratio of risk between two techniques has often been proposed as a more robust assessment of risk than the absolute risk. We found that the ratio of risk between two techniques could also vary substantially considering the different approaches to risk estimation. Sometimes the ratio of risk between two techniques would range between values smaller and larger than one, which then translates into inconsistent results on the potential higher risk of one technique compared to another. We found however that the hybrid IMRT technique resulted in a systematic reduction of risk compared to the other techniques investigated even though the magnitude of this reduction varied substantially with the different approaches investigated. Based on the epidemiological data available, a reasonable

  15. Biocompatible 3D printed polymers via fused deposition modelling direct C2C12 cellular phenotype in vitro.

    PubMed

    Rimington, Rowan P; Capel, Andrew J; Christie, Steven D R; Lewis, Mark P

    2017-08-22

    The capability to 3D print bespoke biologically receptive parts within short time periods has driven the growing prevalence of additive manufacture (AM) technology within biological settings, however limited research concerning cellular interaction with 3D printed polymers has been undertaken. In this work, we used skeletal muscle C2C12 cell line in order to ascertain critical evidence of cellular behaviour in response to multiple bio-receptive candidate polymers; polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET) and polycarbonate (PC) 3D printed via fused deposition modelling (FDM). The extrusion based nature of FDM elicited polymer specific topographies, within which C2C12 cells exhibited reduced metabolic activity when compared to optimised surfaces of tissue culture plastic, however assay viability readings remained high across polymers outlining viable phenotypes. C2C12 cells exhibited consistently high levels of morphological alignment across polymers, however differential myotube widths and levels of transcriptional myogenin expression appeared to demonstrate response specific thresholds at which varying polymer selection potentiates cellular differentiation, elicits pre-mature early myotube formation and directs subsequent morphological phenotype. Here we observed biocompatible AM polymers manufactured via FDM, which also appear to hold the potential to simultaneously manipulate the desired biological phenotype and enhance the biomimicry of skeletal muscle cells in vitro via AM polymer choice and careful selection of machine processing parameters. When considered in combination with the associated design freedom of AM, this may provide the opportunity to not only enhance the efficiency of creating biomimetic models, but also to precisely control the biological output within such scaffolds.

  16. Model-based deduction of CMYK surface coverages from visible and infrared spectral measurements of halftone prints

    NASA Astrophysics Data System (ADS)

    Bugnon, Thomas; Brichon, Mathieu; Hersch, Roger David

    2007-01-01

    The Yule-Nielsen modified Spectral Neugebauer reflection prediction model enhanced with an ink spreading model provides high accuracy when predicting reflectance spectra from ink surface coverages. In the present contribution, we try to inverse the model, i.e. to deduce the surface coverages of a printed color halftone patch from its measured reflectance spectrum. This process yields good results for cyan, magenta, and yellow inks, but unstable results when simultaneously fitting cyan, magenta, yellow, and black inks due to redundancy between these four inks: black can be obtained by printing either the black ink or similar amounts of the cyan, magenta, and yellow inks. To overcome this problem, we use the fact that the black pigmented ink absorbs light in the infrared domain, whereas cyan, magenta, and yellow inks do not. Therefore, with reflection spectra measurements spanning both the visible and infrared domain, it is possible to accurately deduce the black ink coverage. Since there is no redundancy anymore, the cyan, magenta, yellow, and pigmented black ink coverages can be recovered with high accuracy.

  17. 3D printing of modified-release aminosalicylate (4-ASA and 5-ASA) tablets.

    PubMed

    Goyanes, Alvaro; Buanz, Asma B M; Hatton, Grace B; Gaisford, Simon; Basit, Abdul W

    2015-01-01

    The aim of this study was to explore the potential of fused-deposition 3-dimensional printing (FDM 3DP) to produce modified-release drug loaded tablets. Two aminosalicylate isomers used in the treatment of inflammatory bowel disease (IBD), 5-aminosalicylic acid (5-ASA, mesalazine) and 4-aminosalicylic acid (4-ASA), were selected as model drugs. Commercially produced polyvinyl alcohol (PVA) filaments were loaded with the drugs in an ethanolic drug solution. A final drug-loading of 0.06% w/w and 0.25% w/w was achieved for the 5-ASA and 4-ASA strands, respectively. 10.5mm diameter tablets of both PVA/4-ASA and PVA/5-ASA were subsequently printed using an FDM 3D printer, and varying the weight and densities of the printed tablets was achieved by selecting the infill percentage in the printer software. The tablets were mechanically strong, and the FDM 3D printing was shown to be an effective process for the manufacture of the drug, 5-ASA. Significant thermal degradation of the active 4-ASA (50%) occurred during printing, however, indicating that the method may not be appropriate for drugs when printing at high temperatures exceeding those of the degradation point. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of the formulated blends confirmed these findings while highlighting the potential of thermal analytical techniques to anticipate drug degradation issues in the 3D printing process. The results of the dissolution tests conducted in modified Hank's bicarbonate buffer showed that release profiles for both drugs were dependent on both the drug itself and on the infill percentage of the tablet. Our work here demonstrates the potential role of FDM 3DP as an efficient and low-cost alternative method of manufacturing individually tailored oral drug dosage, and also for production of modified-release formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Molecular Signatures in the Prevention of Radiation Damage by the Synergistic Effect of N-Acetyl Cysteine and Qingre Liyan Decoction, a Traditional Chinese Medicine, Using a 3-Dimensional Cell Culture Model of Oral Mucositis

    PubMed Central

    Lambros, Maria P.; Kondapalli, Lavanya; Parsa, Cyrus; Mulamalla, Hari Chandana; Orlando, Robert; Pon, Doreen; Huang, Ying; Chow, Moses S. S.

    2015-01-01

    Qingre Liyan decoction (QYD), a Traditional Chinese medicine, and N-acetyl cysteine (NAC) have been used to prevent radiation induced mucositis. This work evaluates the protective mechanisms of QYD, NAC, and their combination (NAC-QYD) at the cellular and transcriptional level. A validated organotypic model of oral mucosal consisting of a three-dimensional (3D) cell tissue-culture of primary human keratinocytes exposed to X-ray irradiation was used. Six hours after the irradiation, the tissues were evaluated by hematoxylin and eosin (H and E) and a TUNEL assay to assess histopathology and apoptosis, respectively. Total RNA was extracted and used for microarray gene expression profiling. The tissue-cultures treated with NAC-QYD preserved their integrity and showed no apoptosis. Microarray results revealed that the NAC-QYD caused the upregulation of genes encoding metallothioneins, HMOX1, and other components of the Nrf2 pathway, which protects against oxidative stress. DNA repair genes (XCP, GADD45G, RAD9, and XRCC1), protective genes (EGFR and PPARD), and genes of the NFκB pathway were upregulated. Finally, tissue-cultures treated prophylactically with NAC-QYD showed significant downregulation of apoptosis, cytokines and chemokines genes, and constrained damage-associated molecular patterns (DAMPs). NAC-QYD treatment involves the protective effect of Nrf2, NFκB, and DNA repair factors. PMID:25705238

  19. Contribution of seismic processing to put up the scaffolding for the 3-dimensional study of deep sedimentary basins: the fundaments of trans-national 3D modelling in the project GeoMol

    NASA Astrophysics Data System (ADS)

    Capar, Laure

    2013-04-01

    Within the framework of the transnational project GeoMol geophysical and geological information on the entire Molasse Basin and on the Po Basin are gathered to build consistent cross-border 3D geological models based on borehole evidence and seismic data. Benefiting from important progress in seismic processing, these new models will provide some answers to various questions regarding the usage of subsurface resources, as there are geothermal energy, CO2 and gas storage, oil and gas production, and support decisions-making to national and local administrations as well as to industries. More than 28 000 km of 2D seismic lines are compiled reprocessed and harmonized. This work faces various problems like the vertical drop of more than 700 meters between West and East of the Molasse Basin and to al lesser extent in the Po Plain, the heterogeneities of the substratum, the large disparities between the period and parameters of seismic acquisition, and depending of their availability, the use of two types of seismic data, raw and processed seismic data. The main challenge is to harmonize all lines at the same reference level, amplitude and step of signal processing from France to Austria, spanning more than 1000 km, to avoid misfits at crossing points between seismic lines and artifacts at the country borders, facilitating the interpretation of the various geological layers in the Molasse Basin and Po Basin. A generalized stratigraphic column for the two basins is set up, representing all geological layers relevant to subsurface usage. This stratigraphy constitutes the harmonized framework for seismic reprocessing. In general, processed seismic data is available on paper at stack stage and the mandatory information to take these seismic lines to the final stage of processing, the migration step, are datum plane and replacement velocity. However several datum planes and replacement velocities were used during previous processing projects. Our processing sequence is to

  20. Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model

    PubMed Central

    Zhang, Haifeng; Mao, Xiyuan; Du, Zijing; Jiang, Wenbo; Han, Xiuguo; Zhao, Danyang; Han, Dong; Li, Qingfeng

    2016-01-01

    Abstract We have explored the applicability of printed scaffold by comparing osteogenic ability and biodegradation property of three resorbable biomaterials. A polylactic acid/hydroxyapatite (PLA/HA) composite with a pore size of 500 μm and 60% porosity was fabricated by three-dimensional printing. Three-dimensional printed PLA/HA, β-tricalcium phosphate (β-TCP) and partially demineralized bone matrix (DBM) seeded with bone marrow stromal cells (BMSCs) were evaluated by cell adhesion, proliferation, alkaline phosphatase activity and osteogenic gene expression of osteopontin (OPN) and collagen type I (COL-1). Moreover, the biocompatibility, bone repairing capacity and degradation in three different bone substitute materials were estimated using a critical-size rat calvarial defect model in vivo. The defects were evaluated by micro-computed tomography and histological analysis at four and eight weeks after surgery, respectively. The results showed that each of the studied scaffolds had its own specific merits and drawbacks. Three-dimensional printed PLA/HA scaffolds possessed good biocompatibility and stimulated BMSC cell proliferation and differentiation to osteogenic cells. The outcomes in vivo revealed that 3D printed PLA/HA scaffolds had good osteogenic capability and biodegradation activity with no difference in inflammation reaction. Therefore, 3D printed PLA/HA scaffolds have potential applications in bone tissue engineering and may be used as graft substitutes in reconstructive surgery. PMID:27877865

  1. Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model.

    PubMed

    Zhang, Haifeng; Mao, Xiyuan; Du, Zijing; Jiang, Wenbo; Han, Xiuguo; Zhao, Danyang; Han, Dong; Li, Qingfeng

    2016-01-01

    We have explored the applicability of printed scaffold by comparing osteogenic ability and biodegradation property of three resorbable biomaterials. A polylactic acid/hydroxyapatite (PLA/HA) composite with a pore size of 500 μm and 60% porosity was fabricated by three-dimensional printing. Three-dimensional printed PLA/HA, β-tricalcium phosphate (β-TCP) and partially demineralized bone matrix (DBM) seeded with bone marrow stromal cells (BMSCs) were evaluated by cell adhesion, proliferation, alkaline phosphatase activity and osteogenic gene expression of osteopontin (OPN) and collagen type I (COL-1). Moreover, the biocompatibility, bone repairing capacity and degradation in three different bone substitute materials were estimated using a critical-size rat calvarial defect model in vivo. The defects were evaluated by micro-computed tomography and histological analysis at four and eight weeks after surgery, respectively. The results showed that each of the studied scaffolds had its own specific merits and drawbacks. Three-dimensional printed PLA/HA scaffolds possessed good biocompatibility and stimulated BMSC cell proliferation and differentiation to osteogenic cells. The outcomes in vivo revealed that 3D printed PLA/HA scaffolds had good osteogenic capability and biodegradation activity with no difference in inflammation reaction. Therefore, 3D printed PLA/HA scaffolds have potential applications in bone tissue engineering and may be used as graft substitutes in reconstructive surgery.

  2. Corrective Osteotomy of Malunited Diaphyseal Fractures of the Forearm Simplified Using 3-Dimensional CT Data: Proposal of Our Simple Strategy Through Case Presentation.

    PubMed

    Hamada, Yoshitaka; Gotani, Hiroyuki; Sasaki, Kousuke; Tanaka, Yoshitaka; Egawa, Hiroshi; Kanchanathepsak, Thepparat

    2017-09-01

    Reconstruction of malunited diaphyseal fractures of the forearm is one of the most difficult treatments due to its complicated structure. Widespread usage of Digital Imaging and Communications in Medicine (DICOM) data of 3-dimensional (3D) computed tomography (CT) and 3D printing can make estimating the true plane of the deformity easy. A 21-year-old man with limited supination due to left forearm nonunion deformity initially treated by locking plate fixation was referred to our hospital. We evaluated the deformity by superimposing the mirror image bone model of the contralateral normal bone onto a model of the affected bone and 3D real full-scale bone model. The patient underwent a manual corrective osteotomy according to our planning. He had satisfactory improvement of his symptoms with no complications. We postulated that our simple preoperative simulation and manual osteotomy with the aid of 3D CT reconstruction and 3D real full-scale bone model fit in the clinical practice as a recent trend.

  3. The utility of a multimaterial 3D printed model for surgical planning of complex deformity of the skull base and craniovertebral junction.

    PubMed

    Pacione, Donato; Tanweer, Omar; Berman, Phillip; Harter, David H

    2016-11-01

    Utilizing advanced 3D printing techniques, a multimaterial model was created for the surgical planning of a complex deformity of the skull base and craniovertebral junction. The model contained bone anatomy as well as vasculature and the previously placed occipital cervical instrumentation. Careful evaluation allowed for a unique preoperative perspective of the craniovertebral deformity and instrumentation options. This patient-specific model was invaluable in choosing the most effective approach and correction strategy, which was not readily apparent from standard 2D imaging. Advanced 3D multimaterial printing provides a cost-effective method of presurgical planning, which can also be used for both patient and resident education.

  4. Revised OPTSA Model. Volume 3. The OPTSA Print-Run Program

    DTIC Science & Technology

    1975-06-01

    MS»KaA-l BAVUL(KBA).FI4( 2 ,M5)*BAF8( 2 ,MS)» BANF ( 2 ,MS) CONTINUE HRITE(MOTimi IRABA 111 FORMAT (IHOtSlMBLUE A IHBASE--ttLUt LOSSE< CAUSFO BY...IINGLASSIFe SECUWITY CLAStlFICATIOM OF TMH ^AGE r»>>.n O.la gnft,d) REPORT DOCUMENTATION PAGE I. REPORT NUMBER P-1111 2 . OOVT ACCCtSION MO 4...PRINT-RUN PROGRAM DESCRIPTION 1 A. Purpose of the Program 1 B. The Computer Program 2 1. Program Structure and Segments 2 2 . Input 4 3

  5. Cohomological rigidity of manifolds defined by 3-dimensional polytopes

    NASA Astrophysics Data System (ADS)

    Buchstaber, V. M.; Erokhovets, N. Yu.; Masuda, M.; Panov, T. E.; Park, S.

    2017-04-01

    A family of closed manifolds is said to be cohomologically rigid if a cohomology ring isomorphism implies a diffeomorphism for any two manifolds in the family. Cohomological rigidity is established here for large families of 3-dimensional and 6-dimensional manifolds defined by 3-dimensional polytopes. The class \\mathscr{P} of 3-dimensional combinatorial simple polytopes P different from tetrahedra and without facets forming 3- and 4-belts is studied. This class includes mathematical fullerenes, that is, simple 3- polytopes with only 5-gonal and 6-gonal facets. By a theorem of Pogorelov, any polytope in \\mathscr{P} admits in Lobachevsky 3-space a right-angled realisation which is unique up to isometry. Our families of smooth manifolds are associated with polytopes in the class \\mathscr{P}. The first family consists of 3-dimensional small covers of polytopes in \\mathscr{P}, or equivalently, hyperbolic 3-manifolds of Löbell type. The second family consists of 6-dimensional quasitoric manifolds over polytopes in \\mathscr{P}. Our main result is that both families are cohomologically rigid, that is, two manifolds M and M' from either family are diffeomorphic if and only if their cohomology rings are isomorphic. It is also proved that if M and M' are diffeomorphic, then their corresponding polytopes P and P' are combinatorially equivalent. These results are intertwined with classical subjects in geometry and topology such as the combinatorics of 3-polytopes, the Four Colour Theorem, aspherical manifolds, a diffeomorphism classification of 6-manifolds, and invariance of Pontryagin classes. The proofs use techniques of toric topology. Bibliography: 69 titles.

  6. Multimodality 3-Dimensional Image Integration for Congenital Cardiac Catheterization

    PubMed Central

    2014-01-01

    Cardiac catheterization procedures for patients with congenital and structural heart disease are becoming more complex. New imaging strategies involving integration of 3-dimensional images from rotational angiography, magnetic resonance imaging (MRI), computerized tomography (CT), and transesophageal echocardiography (TEE) are employed to facilitate these procedures. We discuss the current use of these new 3D imaging technologies and their advantages and challenges when used to guide complex diagnostic and interventional catheterization procedures in patients with congenital heart disease. PMID:25114757

  7. 3-Dimensional modeling of protein structures distinguishes closely related phytoplasmas

    USDA-ARS?s Scientific Manuscript database

    Phytoplasmas (formerly mycoplasmalike organisms, MLOs) are cell wall-less bacteria that inhabit phloem tissue of plants and are transmitted from plant-to-plant by phloem-feeding insects. Numerous diseases affecting hundreds of plant species in many botanical families are attributed to infections by...

  8. Theoretic model and computer simulation of separating mixture metal particles from waste printed circuit board by electrostatic separator.

    PubMed

    Li, Jia; Xu, Zhenming; Zhou, Yaohe

    2008-05-30

    Traditionally, the mixture metals from waste printed circuit board (PCB) were sent to the smelt factory to refine pure copper. Some valuable metals (aluminum, zinc and tin) with low content in PCB were lost during smelt. A new method which used roll-type electrostatic separator (RES) to recovery low content metals in waste PCB was presented in this study. The theoretic model which was established from computing electric field and the analysis of forces on the particles was used to write a program by MATLAB language. The program was design to simulate the process of separating mixture metal particles. Electrical, material and mechanical factors were analyzed to optimize the operating parameters of separator. The experiment results of separating copper and aluminum particles by RES had a good agreement with computer simulation results. The model could be used to simulate separating other metal (tin, zinc, etc.) particles during the process of recycling waste PCBs by RES.

  9. Quantification of the uncertainty in coronary CTA plaque measurements using dynamic cardiac phantom and 3D-printed plaque models

    NASA Astrophysics Data System (ADS)

    Richards, Taylor; Sturgeon, Gregory M.; Ramirez-Giraldo, Juan Carlos; Rubin, Geoffrey; Segars, Paul; Samei, Ehsan

    2017-03-01

    The purpose of this study was to quantify the accuracy of coronary computed tomography angiography (CTA) stenosis measurements using newly developed physical coronary plaque models attached to a base dynamic cardiac phantom (Shelley Medical DHP-01). Coronary plaque models (5 mm diameter, 50% stenosis, and 32 mm long) were designed and 3D-printed with tissue equivalent materials (calcified plaque with iodine enhanced lumen). Realistic cardiac motion was achieved by fitting known cardiac motion vectors to left ventricle volume-time curves to create synchronized heart motion profiles executed by the base cardiac phantom. Realistic coronary CTA acquisition was accomplished by synthesizing corresponding ECG waveforms for gating and reconstruction purposes. All scans were acquired using a retrospective gating technique on a dual-source CT system (Siemens SOMATOM FLASH) with 75ms temporal resolution. Multi-planar reformatted images were reconstructed along vessel centerlines and the enhanced lumens were manually segmented by 5 independent operators. On average, the stenosis measurement accuracy was 0.9% positive bias for the motion free condition (0 bpm). The measurement accuracy monotonically decreased to 18.5% negative bias at 90 bpm. Contrast-tonoise (CNR), vessel circularity, and segmentation conformity also decreased monotonically with increasing heart rate. These results demonstrate successful implementation of the base cardiac phantom with 3D-printed coronary plaque models, adjustable motion profiles, and coordinated ECG waveforms. They further show the utility of the model to ascertain metrics of coronary CT accuracy and image quality under a variety of plaque, motion, and acquisition conditions.

  10. 3D printing PLGA: a quantitative examination of the effects of polymer composition and printing parameters on print resolution.

    PubMed

    Guo, Ting; Holzberg, Timothy R; Lim, Casey G; Gao, Feng; Gargava, Ankit; Trachtenberg, Jordan E; Mikos, Antonios G; Fisher, John P

    2017-04-12

    In the past few decades, 3D printing has played a significant role in fabricating scaffolds with consistent, complex structure that meet patient-specific needs in future clinical applications. Although many studies have contributed to this emerging field of additive manufacturing, which includes material development and computer-aided scaffold design, current quantitative analyses do not correlate material properties, printing parameters, and printing outcomes to a great extent. A model that correlates these properties has tremendous potential to standardize 3D printing for tissue engineering and biomaterial science. In this study, we printed poly(lactic-co-glycolic acid) (PLGA) utilizing a direct melt extrusion technique without additional ingredients. We investigated PLGA with various lactic acid:glycolic acid (LA:GA) molecular weight ratios and end caps to demonstrate the dependence of the extrusion process on the polymer composition. Micro-computed tomography was then used to evaluate printed scaffolds containing different LA:GA ratios, composed of different fiber patterns, and processed under different printing conditions. We built a statistical model to reveal the correlation and predominant factors that determine printing precision. Our model showed a strong linear relationship between the actual and predicted precision under different combinations of printing conditions and material compositions. This quantitative examination establishes a significant foreground to 3D print biomaterials following a systematic fabrication procedure. Additionally, our proposed statistical models can be applied to couple specific biomaterials and 3D printing applications for patient implants with particular requirements.

  11. Development of monograph titled "augmented chemistry aldehida & keton" with 3 dimensional (3D) illustration as a supplement book on chemistry learning

    NASA Astrophysics Data System (ADS)

    Damayanti, Latifah Adelina; Ikhsan, Jaslin

    2017-05-01

    Integration of information technology in education more rapidly performed in a medium of learning. Three-dimensional (3D) molecular modeling was performed in Augmented Reality as a tangible manifestation of increasingly modern technology utilization. Based on augmented reality, three-dimensional virtual object is projected in real time and the exact environment. This paper reviewed the uses of chemical learning supplement book of aldehydes and ketones which are equipped with three-dimensional molecular modeling by which students can inspect molecules from various viewpoints. To plays the 3D illustration printed on the book, smartphones with the open-source software of the technology based integrated Augmented Reality can be used. The aims of this research were to develop the monograph of aldehydes and ketones with 3 dimensional (3D) illustrations, to determine the specification of the monograph, and to determine the quality of the monograph. The quality of the monograph is evaluated by experiencing chemistry teachers on the five aspects of contents/materials, presentations, language and images, graphs, and software engineering, resulted in the result that the book has a very good quality to be used as a chemistry learning supplement book.

  12. [Bile duct reconstruction using 3-dimensional collagen tubes].

    PubMed

    Pérez Alonso, Alejandro José; del Olmo Rivas, Carlos; Machado Romero, Ignacio; Pérez Cabrera, Beatriz; Cañizares Garcia, Francisco Javier; Torne Poyatos, Pablo

    2013-11-01

    In recent years, with widespread laparoscopic cholecystectomy and liver transplantation, complications involving the biliary system are increasing. All current techniques have a high risk of recurrence or high-morbidity. A 3-dimensional collagen bile duct modified with agarose hydrogel was developed to substitute the affected extrahepatic bile duct. It was used in 40 guinea pigs and the histology and physiology was studied at 4 weeks, 3 and 6 months after transplantation. The graft shows to have a high potential in applications to treat hepatobiliary diseases which require surgery. Copyright © 2012 AEC. Published by Elsevier Espana. All rights reserved.

  13. 3-dimensional electronic structures of CaC6

    NASA Astrophysics Data System (ADS)

    Kyung, Wonshik; Kim, Yeongkwan; Han, Garam; Leem, Choonshik; Kim, Junsung; Kim, Yeongwook; Kim, Keunsu; Rotenberg, Eli; Kim, Changyoung; Postech Collaboration; Advanced Light Source Collaboration; Yonsei University Team

    2014-03-01

    There is still remaining issues on origin of superconductivity in graphite intercalation compounds, especially CaC6 because of its relatively high transition temperature than other GICs. There are two competing theories on where the superconductivity occurs in this material; intercalant metal or charge doped graphene layer. To elucidate this issue, it is necessary to confirm existence of intercalant driven band. Therefore, we performed 3 dimensional electronic structure studies with ARPES to find out 3d dispersive intercalant band. However, we could not observe it, instead observed 3d dispersive carbon band. This support the aspect of charge doped graphene superconductivity more than intercalant driving aspect.

  14. Printing-induced cell injury evaluation during laser printing of 3T3 mouse fibroblasts.

    PubMed

    Zhang, Zhengyi; Chai, Wenxuan; Xiong, Ruitong; Zhou, Lei; Huang, Yong

    2017-06-20

    Three-dimensional bioprinting has emerged as a promising solution for the freeform fabrication of living cellular constructs, which can be used for tissue/organ transplantation and tissue models. During bioprinting, some living cells are unavoidably injured and may become necrotic or apoptotic cells. This study aims to investigate the printing-induced cell injury and evaluates injury types of post-printing cells using the annexin V/7-aminoactinomycin D and FAM-DEVD-FMK/propidium iodide assays during laser printing of NIH 3T3 mouse fibroblasts. As observed, the percentage of post-printing early apoptotic mouse fibroblasts increases with the incubation time, indicating that post-printing apoptotic mouse fibroblasts have different initiation lag times of apoptosis due to different levels of mechanical stress exerted during laser printing. Post-printing necrotic mouse fibroblasts can be detected immediately after printing, while post-printing early apoptotic mouse fibroblasts need time to develop into a late apoptotic stage. The minimum time needed for post-printing early apoptotic mouse fibroblasts to complete their apoptosis pathway and transition into late apoptotic mouse fibroblasts is from 4 h to 5 h post-printing. The resulting knowledge of the evolution of different apoptotic post-printing mouse fibroblasts will help better design future experiments to quantitatively determine, model, and mitigate the post-printing cell injury based on molecular signal pathway modeling.

  15. Evaluation of pre-surgical models for uterine surgery by use of three-dimensional printing and mold casting.

    PubMed

    Sayed Aluwee, Sayed Ahmad Zikri Bin; Zhou, Xiangrong; Kato, Hiroki; Makino, Hiroshi; Muramatsu, Chisako; Hara, Takeshi; Matsuo, Masayuki; Fujita, Hiroshi

    2017-04-12

    We propose an approach to supporting pre-surgical planning for the uterus by integrating medical image analysis and physical model generation based on 3D printing. With our method, we first segment the patient-specific anatomy and lesions of the uterus on MR images; then, we create a 3D physical model, an exact replica of the patient's uterus in terms of size and softness, with transparency for easy observation of the internal structures of the uterus. In our experiments, we created pre-surgical models of hysterectomy for five patients who had been diagnosed to have uterine endometrial cancer. An experienced radiologist, the surgeons, and all of the patients cooperated in our experiment for carrying out subjective evaluations of the usefulness of our model. The accuracy of the physical models was evaluated quantitatively by comparison between the MR images of the patients and the CT images of the models. The results showed that the mean values of the errors in gap ranged from 1.19 to 2.22 mm, which was satisfactory for the surgeons. The feedback from both surgeons and patients demonstrated the usefulness and convenience of the models for efficient patient explanation understanding and pre-surgical planning by surgeons.

  16. [Reconstruction assisted by 3D printing in maxillofacial surgery].

    PubMed

    Ernoult, C; Bouletreau, P; Meyer, C; Aubry, S; Breton, P; Bachelet, J-T

    2015-04-01

    3-dimensional models (3D) appeared in the medical field 20 years ago. The recent development of consumer 3D printers explains the renewed interest in this technology. We describe the technical and practical modalities of this surgical tool, illustrated by concrete examples. The OsiriX(®) software (version 5.8.5, Geneva, Switzerland) was used for 3D surface reconstruction of the area of interest, the generation and export of ".stl" file. The NetFabb(®) software (Basic version 5.1.1, Lupburg, Germany) provided the preparation of ".stl" file. The 3D-printer was an Up plus 2 Easy 120(®) (PP3DP, Beijing Technology Co. TierTime Ltd., Chine). The printer used fused deposition modeling. The softwar Up!(®) allowed the 3d impression as required. The first case illustrated the value of 3D printing in the upper (frontal sinus and orbital roof). The second case concerned the preconfiguration of the osteosynthesis material for a complex fracture of the midface through the "mirroring" system. The third case showed the conformation of a prereconstruction for segmental mandibulectomy. Current 3D-printers are easy to use and represent a promising solution for medical prototyping. The 3D printing will quickly become undeniable because of its advantages: information sharing, simulation, surgical guides, pedagogy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. Therapeutic response assessment using 3D ultrasound for hepatic metastasis from colorectal cancer: Application of a personalized, 3D-printed tumor model using CT images

    PubMed Central

    Choi, Ye Ra; Park, Sang Joon; Hur, Bo Yun; Han, Joon Koo

    2017-01-01

    Background & aims To evaluate accuracy and reliability of three-dimensional ultrasound (3D US) for response evaluation of hepatic metastasis from colorectal cancer (CRC) using a personalized 3D-printed tumor model. Methods Twenty patients with liver metastasis from CRC who underwent baseline and after chemotherapy CT, were retrospectively included. Personalized 3D-printed tumor models using CT were fabricated. Two radiologists measured volume of each 3D printing model using 3D US. With CT as a reference, we compared difference between CT and US tumor volume. The response evaluation was based on Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Results 3D US tumor volume showed no significant difference from CT volume (7.18 ± 5.44 mL, 8.31 ± 6.32 mL vs 7.42 ± 5.76 mL in CT, p>0.05). 3D US provided a high correlation coefficient with CT (r = 0.953, r = 0.97) as well as a high inter-observer intraclass correlation (0.978; 0.958–0.988). Regarding response, 3D US was in agreement with CT in 17 and 18 out of 20 patients for observer 1 and 2 with excellent agreement (κ = 0.961). Conclusions 3D US tumor volume using a personalized 3D-printed model is an accurate and reliable method for the response evaluation in comparison with CT tumor volume. PMID:28797089

  18. A Straightforward Approach for 3D Bacterial Printing

    PubMed Central

    2017-01-01

    Sustainable and personally tailored materials production is an emerging challenge to society. Living organisms can produce and pattern an extraordinarily wide range of different molecules in a sustainable way. These natural systems offer an abundant source of inspiration for the development of new environmentally friendly materials production techniques. In this paper, we describe the first steps toward the 3-dimensional printing of bacterial cultures for materials production and patterning. This methodology combines the capability of bacteria to form new materials with the reproducibility and tailored approach of 3D printing systems. For this purpose, a commercial 3D printer was modified for bacterial systems, and new alginate-based bioink chemistry was developed. Printing temperature, printhead speed, and bioink extrusion rate were all adapted and customized to maximize bacterial health and spatial resolution of printed structures. Our combination of 3D printing technology with biological systems enables a sustainable approach for the production of numerous new materials. PMID:28225616

  19. A Straightforward Approach for 3D Bacterial Printing.

    PubMed

    Lehner, Benjamin A E; Schmieden, Dominik T; Meyer, Anne S

    2017-03-01

    Sustainable and personally tailored materials production is an emerging challenge to society. Living organisms can produce and pattern an extraordinarily wide range of different molecules in a sustainable way. These natural systems offer an abundant source of inspiration for the development of new environmentally friendly materials production techniques. In this paper, we describe the first steps toward the 3-dimensional printing of bacterial cultures for materials production and patterning. This methodology combines the capability of bacteria to form new materials with the reproducibility and tailored approach of 3D printing systems. For this purpose, a commercial 3D printer was modified for bacterial systems, and new alginate-based bioink chemistry was developed. Printing temperature, printhead speed, and bioink extrusion rate were all adapted and customized to maximize bacterial health and spatial resolution of printed structures. Our combination of 3D printing technology with biological systems enables a sustainable approach for the production of numerous new materials.

  20. Incorporating a 3-dimensional printer into the management of early-stage cervical cancer.

    PubMed

    Baek, Min-Hyun; Kim, Dae-Yeon; Kim, Namkug; Rhim, Chae Chun; Kim, Jong-Hyeok; Nam, Joo-Hyun

    2016-08-01

    We used a 3-dimensional (3D) printer to create anatomical replicas of real lesions and tested its application in cervical cancer. Our study patient decided to undergo radical hysterectomy after seeing her 3D model which was then used to plan and simulate this surgery. Using 3D printers to create patient-specific 3D tumor models may aid cervical cancer patients make treatment decisions. This technology will lead to better surgical and oncological outcomes for cervical cancer patients. J. Surg. Oncol. 2016;114:150-152. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Application of the polystyrene model made by 3-D printing rapid prototyping technology for operation planning in revision lumbar discectomy.

    PubMed

    Li, Chao; Yang, Mingyuan; Xie, Yang; Chen, Ziqiang; Wang, Chuanfeng; Bai, Yushu; Zhu, Xiaodong; Li, Ming

    2015-05-01

    The objective was to evaluate the effectiveness of 3-D rapid prototyping technology in revision lumbar discectomy. 3-D rapid prototyping technology has not been reported in the treatment of revision lumbar discectomy. Patients with recurrent lumbar disc herniation who were preparing to undergo revision lumbar discectomy from a single center between January 2011 and 2013 were included in this analysis. Patients were divided into two groups. In group A, 3-D printing technology was used to create subject-specific lumbar vertebral models in the preoperative planning process. Group B underwent lumbar revision as usual. Preoperative and postoperative clinical outcomes were compared between groups included operation time, perioperative blood loss, postoperative complications, Oswestry Disability Index (ODI), Japan Orthopaedics Association (JOA) scores, and visual analogue scale (VAS) scores for back pain and leg pain. A total of 37 patients were included in this study (Group A = 15, Group B = 22). Group A had a significantly shorter operation time (106.53 ± 11.91 vs. 131.92 ± 10.81 min, P < 0.001) and significantly less blood loss (341.67 ± 49.45 vs. 466.77 ± 71.46 ml, P < 0.001). There was no difference between groups for complication rate. There were also no differences between groups for any clinical metric. Using the 3-D printing technology before revision lumbar discectomy may reduce the operation time and the perioperative blood loss. There does not appear to be a benefit to using the technology with respect to clinical outcomes. Future prospective studies are needed to further elucidate the efficacy of this emerging technology.

  2. 3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System

    PubMed Central

    Walter, Teagan J.; Sparks, Erin E.; Huppert, Stacey S.

    2012-01-01

    In organs, the correct architecture of vascular and ductal structures is indispensable for proper physiological function, and the formation and maintenance of these structures is a highly regulated process. The analysis of these complex, 3-dimensional structures has greatly depended on either 2-dimensional examination in section or on dye injection studies. These techniques, however, are not able to provide a complete and quantifiable representation of the ductal or vascular structures they are intended to elucidate. Alternatively, the nature of 3-dimensional plastic resin casts generates a permanent snapshot of the system and is a novel and widely useful technique for visualizing and quantifying 3-dimensional structures and networks. A crucial advantage of the resin casting system is the ability to determine the intact and connected, or communicating, structure of a blood vessel or duct. The structure of vascular and ductal networks are crucial for organ function, and this technique has the potential to aid study of vascular and ductal networks in several ways. Resin casting may be used to analyze normal morphology and functional architecture of a luminal structure, identify developmental morphogenetic changes, and uncover morphological differences in tissue architecture between normal and disease states. Previous work has utilized resin casting to study, for example, architectural and functional defects within the mouse intrahepatic bile duct system that were not reflected in 2-dimensional analysis of the structure1,2, alterations in brain vasculature of a Alzheimer's disease mouse model3, portal vein abnormalities in portal hypertensive and cirrhotic mice4, developmental steps in rat lymphatic maturation between immature and adult lungs5, immediate microvascular changes in the rat liver, pancreas, and kidney in response in to chemical injury6. Here we present a method of generating a 3-dimensional resin cast of a mouse vascular or ductal network, focusing

  3. Scene-of-crime analysis by a 3-dimensional optical digitizer: a useful perspective for forensic science.

    PubMed

    Sansoni, Giovanna; Cattaneo, Cristina; Trebeschi, Marco; Gibelli, Daniele; Poppa, Pasquale; Porta, Davide; Maldarella, Monica; Picozzi, Massimo

    2011-09-01

    Analysis and detailed registration of the crime scene are of the utmost importance during investigations. However, this phase of activity is often affected by the risk of loss of evidence due to the limits of traditional scene of crime registration methods (ie, photos and videos). This technical note shows the utility of the application of a 3-dimensional optical digitizer on different crime scenes. This study aims in fact at verifying the importance and feasibility of contactless 3-dimensional reconstruction and modeling by optical digitization to achieve an optimal registration of the crime scene.

  4. Critical rotational speed model of the rotating roll electrode in corona electrostatic separation for recycling waste printed circuit boards.

    PubMed

    Li, Jia; Lu, Hongzhou; Xu, Zhenming; Zhou, Yaohe

    2008-06-15

    Waste printed circuit board (PCB) is increasing worldwide. The corona electrostatic separation (CES) was an effective and environmental protection way to recycle resource from waste PCBs. The aim of this paper is to analyze the main factor (rotational speed) that affects the efficiency of CES from the point of view of electrostatics and mechanics. A quantitative method for analyzing the affection of rotational speed was studied and the model for separating flat nonmetal particles in waste PCBs was established. The conception of "charging critical rotational speed" and "detaching critical rotational speed" were presented. Experiments with the waste PCBs verified the theoretical model, and the experimental results were in good agreement with the theoretical model. The results indicated that the purity and recycle percentage of materials got a good level when the rotational speed was about 70 rpm and the critical rotational speed of small particles was higher than big particles. The model can guide the definition of operator parameter and the design of CES, which are needed for the development of any new application of the electrostatic separation method.

  5. Analytical modeling of conformal mantle cloaks for cylindrical objects using sub-wavelength printed and slotted arrays

    NASA Astrophysics Data System (ADS)

    Padooru, Yashwanth R.; Yakovlev, Alexander B.; Chen, Pai-Yen; Alù, Andrea

    2012-08-01

    Following the idea of "cloaking by a surface" [A. Alù, Phys. Rev. B 80, 245115 (2009); P. Y. Chen and A. Alù, Phys. Rev. B 84, 205110 (2011)], we present a rigorous analytical model applicable to mantle cloaking of cylindrical objects using 1D and 2D sub-wavelength conformal frequency selective surface (FSS) elements. The model is based on Lorenz-Mie scattering theory which utilizes the two-sided impedance boundary conditions at the interface of the sub-wavelength elements. The FSS arrays considered in this work are composed of 1D horizontal and vertical metallic strips and 2D printed (patches, Jerusalem crosses, and cross dipoles) and slotted structures (meshes, slot-Jerusalem crosses, and slot-cross dipoles). It is shown that the analytical grid-impedance expressions derived for the planar arrays of sub-wavelength elements may be successfully used to model and tailor the surface reactance of cylindrical conformal mantle cloaks. By properly tailoring the surface reactance of the cloak, the total scattering from the cylinder can be significantly reduced, thus rendering the object invisible over the range of frequencies of interest (i.e., at microwaves and far-infrared). The results obtained using our analytical model for mantle cloaks are validated against full-wave numerical simulations.

  6. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.

  7. 3D Printed Robotic Hand

    NASA Technical Reports Server (NTRS)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

  8. Scientific visualization of 3-dimensional optimized stellarator configurations

    SciTech Connect

    Spong, D.A.

    1998-01-01

    The design techniques and physics analysis of modern stellarator configurations for magnetic fusion research rely heavily on high performance computing and simulation. Stellarators, which are fundamentally 3-dimensional in nature, offer significantly more design flexibility than more symmetric devices such as the tokamak. By varying the outer boundary shape of the plasma, a variety of physics features, such as transport, stability, and heating efficiency can be optimized. Scientific visualization techniques are an important adjunct to this effort as they provide a necessary ergonomic link between the numerical results and the intuition of the human researcher. The authors have developed a variety of visualization techniques for stellarators which both facilitate the design optimization process and allow the physics simulations to be more readily understood.

  9. Virtual temporal bone: an interactive 3-dimensional learning aid for cranial base surgery.

    PubMed

    Kockro, Ralf A; Hwang, Peter Y K

    2009-05-01

    We have developed an interactive virtual model of the temporal bone for the training and teaching of cranial base surgery. The virtual model was based on the tomographic data of the Visible Human Project. The male Visible Human's computed tomographic data were volumetrically reconstructed as virtual bone tissue, and the individual photographic slices provided the basis for segmentation of the middle and inner ear structures, cranial nerves, vessels, and brainstem. These structures were created by using outlining and tube editing tools, allowing structural modeling either directly on the basis of the photographic data or according to information from textbooks and cadaver dissections. For training and teaching, the virtual model was accessed in the previously described 3-dimensional workspaces of the Dextroscope or Dextrobeam (Volume Interactions Pte, Ltd., Singapore), whose interfaces enable volumetric exploration from any perspective and provide virtual tools for drilling and measuring. We have simulated several cranial base procedures including approaches via the floor of the middle fossa and the lateral petrous bone. The virtual model suitably illustrated the core facts of anatomic spatial relationships while simulating different stages of bone drilling along a variety of surgical corridors. The system was used for teaching during training courses to plan and discuss operative anatomy and strategies. The Virtual Temporal Bone and its surrounding 3-dimensional workspace provide an effective way to study the essential surgical anatomy of this complex region and to teach and train operative strategies, especially when used as an adjunct to cadaver dissections.

  10. 3-dimensional analysis of regenerative endodontic treatment outcome.

    PubMed

    EzEldeen, Mostafa; Van Gorp, Gertrude; Van Dessel, Jeroen; Vandermeulen, Dirk; Jacobs, Reinhilde

    2015-03-01

    A growing body of evidence supports the regeneration potential of dental tissues after regenerative endodontic treatment (RET). Nevertheless, a standard method for the evaluation of RET outcome is lacking. The aim of this study was to develop a standardized quantitative method for RET outcome analysis based on cone-beam computed tomographic (CBCT) volumetric measurements. Five human teeth embedded in mandibular bone samples were scanned using both an Accuitomo 170 CBCT machine (Morita, Kyoto, Japan) and a SkyScan 1174 micro-computed tomographic (μCT) system (SkyScan, Antwerp, Belgium). For subsequent clinical application, clinical data and low-dose CBCT scans (preoperatively and follow-up) from 5 immature permanent teeth treated with RET were retrieved. In vitro and clinical 3-dimensional image data sets were imported into a dedicated software tool. Two segmentation steps were applied to extract the teeth of interest from the surrounding tissue (livewire) and to separate tooth hard tissue and root canal space (level set methods). In vitro and clinical volumetric measurements were assessed separately for differences using Wilcoxon matched pairs test. Pearson correlation analysis and Bland-Altman plots were used to evaluate the relation and agreement between the segmented CBCT and μCT volumes. The results showed no statistical differences and strong agreement between CBCT and μCT volumetric measurements. Volumetric comparison of the root hard tissue showed significant hard tissue formation. (The mean volume of newly formed hard tissue was 27.9 [±10.5] mm(3) [P < .05]). Analysis of 3-dimensional data for teeth treated with RET offers valuable insights into the treatment outcome and patterns of hard tissue formation. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. [Quantitative evaluation of printing accuracy and tissue surface adaptation of mandibular complete denture polylactic acid pattern fabricated by fused deposition modeling technology].

    PubMed

    Deng, K H; Wang, Y; Chen, H; Zhao, Y J; Zhou, Y S; Sun, Y C

    2017-06-09

    Objective: To quantitatively evaluate the adaptation of polylactic acid (PLA) pattern of mandibular complete denture fabricated by fused deposition modeling (FDM) technology. Methods: A mandibular complete denture digital model was designed through a complete denture design software based on a pair of standard maxillomandibular edentulous plaster model and their occlusion bases. Ten PLA mandibular complete dentures were printed with a FDM machine. The dentures were scanned with and without the plaster model using a three-dimensional (3D) scanner. In Geomagic software, the scanning data of printed dentures were registered to its computer aided design (CAD) data, and the printing error was analyzed using the multipoint registration command. For quantitatively evaluating the adaptation of the denture, the data of plaster model and PLA denture were registered to the whole data of denture located in the plaster model using the best-fit alignment command, the 3D deviation of the plaster model and tissue surface of the denture represent the space between them. The overall area was separated into three parts: primary stress-bearing area, secondary stress-bearing area and border seal area, and the average deviations of these three parts were measured. The values were analyzed using analysis of variance. Results: Compared with the CAD data, the printing error was (0.013±0.004) mm. The overall 3D deviation between PLA denture and plaster model was (0.164±0.033) mm, in which the primary stress-bearing area was (0.165± 0.045) mm, the secondary stress-bearing area was (0.153 ± 0.027) mm, the border seal area was (0.186 ± 0.043) mm. These showed a good fit in the majority parts of the FDM denture to the plaster model. No statistically significant difference was observed between the three areas (F=1.857, P=0.175>0.05). Conclusions: Combined with the 3D scanning, CAD and FDM technology, a FDM 3D printing process of complete denture for injection moulding can be established. As

  12. Low-cost, rapidly-developed, 3D printed in vitro corpus callosum model for mucopolysaccharidosis type I

    PubMed Central

    Tabet, Anthony; Gardner, Matthew; Swanson, Sebastian; Crump, Sydney; McMeekin, Austin; Gong, Diana; Tabet, Rebecca; Hacker, Benjamin; Nestrasil, Igor

    2017-01-01

    The rising prevalence of high throughput screening and the general inability of (1) two dimensional (2D) cell culture and (2) in vitro release studies to predict in vivo neurobiological and pharmacokinetic responses in humans has led to greater interest in more realistic three dimensional (3D) benchtop platforms. Advantages of 3D human cell culture over its 2D analogue, or even animal models, include taking the effects of microgeometry and long-range topological features into consideration. In the era of personalized medicine, it has become increasingly valuable to screen candidate molecules and synergistic therapeutics at a patient-specific level, in particular for diseases that manifest in highly variable ways. The lack of established standards and the relatively arbitrary choice of probing conditions has limited in vitro drug release to a largely qualitative assessment as opposed to a predictive, quantitative measure of pharmacokinetics and pharmacodynamics in tissue. Here we report the methods used in the rapid, low-cost development of a 3D model of a mucopolysaccharidosis type I patient’s corpus callosum, which may be used for cell culture and drug release. The CAD model is developed from in vivo brain MRI tracing of the corpus callosum using open-source software, printed with poly (lactic-acid) on a Makerbot Replicator 5X, UV-sterilized, and coated with poly (lysine) for cellular adhesion. Adaptations of material and 3D printer for expanded applications are also discussed. PMID:28357042

  13. Remote Collaborative 3D Printing - Process Investigation

    DTIC Science & Technology

    2016-04-01

    were able to be completely processed end-to-end from an NMCI computer, due to the lack of available slicing software and limitations on connecting NMCI...cleat model were successfully printed. The Ohio-replacement submarine was not able be processed for printing with the available tools and software on...2 2.3. Files printed from Model Libraries and other sources ......................................................... 2 3. SOFTWARE , TOOLS, AND

  14. A 3-dimensional finite-difference method for calculating the dynamic coefficients of seals

    NASA Technical Reports Server (NTRS)

    Dietzen, F. J.; Nordmann, R.

    1989-01-01

    A method to calculate the dynamic coefficients of seals with arbitrary geometry is presented. The Navier-Stokes equations are used in conjunction with the k-e turbulence model to describe the turbulent flow. These equations are solved by a full 3-dimensional finite-difference procedure instead of the normally used perturbation analysis. The time dependence of the equations is introduced by working with a coordinate system rotating with the precession frequency of the shaft. The results of this theory are compared with coefficients calculated by a perturbation analysis and with experimental results.

  15. Design of 3-dimensional complex airplane configurations with specified pressure distribution via optimization

    NASA Technical Reports Server (NTRS)

    Kubrynski, Krzysztof

    1991-01-01

    A subcritical panel method applied to flow analysis and aerodynamic design of complex aircraft configurations is presented. The analysis method is based on linearized, compressible, subsonic flow equations and indirect Dirichlet boundary conditions. Quadratic dipol and linear source distribution on flat panels are applied. In the case of aerodynamic design, the geometry which minimizes differences between design and actual pressure distribution is found iteratively, using numerical optimization technique. Geometry modifications are modeled by surface transpiration concept. Constraints in respect to resulting geometry can be specified. A number of complex 3-dimensional design examples are presented. The software is adopted to personal computers, and as result an unexpected low cost of computations is obtained.

  16. A Graphic Overlay Method for Selection of Osteotomy Site in Chronic Radial Head Dislocation: An Evaluation of 3D-printed Bone Models.

    PubMed

    Kim, Hui Taek; Ahn, Tae Young; Jang, Jae Hoon; Kim, Kang Hee; Lee, Sung Jae; Jung, Duk Young

    2017-03-01

    Three-dimensional (3D) computed tomography imaging is now being used to generate 3D models for planning orthopaedic surgery, but the process remains time consuming and expensive. For chronic radial head dislocation, we have designed a graphic overlay approach that employs selected 3D computer images and widely available software to simplify the process of osteotomy site selection. We studied 5 patients (2 traumatic and 3 congenital) with unilateral radial head dislocation. These patients were treated with surgery based on traditional radiographs, but they also had full sets of 3D CT imaging done both before and after their surgery: these 3D CT images form the basis for this study. From the 3D CT images, each patient generated 3 sets of 3D-printed bone models: 2 copies of the preoperative condition, and 1 copy of the postoperative condition. One set of the preoperative models was then actually osteotomized and fixed in the manner suggested by our graphic technique. Arcs of rotation of the 3 sets of 3D-printed bone models were then compared. Arcs of rotation of the 3 groups of bone models were significantly different, with the models osteotomized accordingly to our graphic technique having the widest arcs. For chronic radial head dislocation, our graphic overlay approach simplifies the selection of the osteotomy site(s). Three-dimensional-printed bone models suggest that this approach could improve range of motion of the forearm in actual surgical practice. Level IV-therapeutic study.

  17. Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant

    SciTech Connect

    Not Available

    2010-12-01

    The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

  18. 3D Printing of Intracranial Aneurysms Using Fused Deposition Modeling Offers Highly Accurate Replications.

    PubMed

    Frölich, A M J; Spallek, J; Brehmer, L; Buhk, J-H; Krause, D; Fiehler, J; Kemmling, A

    2016-01-01

    As part of a multicenter cooperation (Aneurysm-Like Synthetic bodies for Testing Endovascular devices in 3D Reality) with focus on implementation of additive manufacturing in neuroradiologic practice, we systematically assessed the technical feasibility and accuracy of several additive manufacturing techniques. We evaluated the method of fused deposition modeling for the production of aneurysm models replicating patient-specific anatomy. 3D rotational angiographic data from 10 aneurysms were processed to obtain volumetric models suitable for fused deposition modeling. A hollow aneurysm model with connectors for silicone tubes was fabricated by using acrylonitrile butadiene styrene. Support material was dissolved, and surfaces were finished by using NanoSeal. The resulting models were filled with iodinated contrast media. 3D rotational angiography of the models was acquired, and aneurysm geometry was compared with the original patient data. Reproduction of hollow aneurysm models was technically feasible in 8 of 10 cases, with aneurysm sizes ranging from 41 to 2928 mm(3) (aneurysm diameter, 3-19 mm). A high level of anatomic accuracy was observed, with a mean Dice index of 93.6% ± 2.4%. Obstructions were encountered in vessel segments of <1 mm. Fused deposition modeling is a promising technique, which allows rapid and precise replication of cerebral aneurysms. The porosity of the models can be overcome by surface finishing. Models produced with fused deposition modeling may serve as educational and research tools and could be used to individualize treatment planning. © 2016 by American Journal of Neuroradiology.

  19. Early prints depicting eyeglasses.

    PubMed

    Letocha, Charles E; Dreyfus, John

    2002-11-01

    Much of the history of eyeglasses has been gleaned from studies of paintings and prints that illustrate them. A few prints from the first century of printing include spectacles and are reproduced in this article. In addition to showing their form and method of use, these prints also illustrate their symbolic value.

  20. The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty.

    PubMed

    Wijdh-den Hamer, Inez J; Bouma, Wobbe; Lai, Eric K; Levack, Melissa M; Shang, Eric K; Pouch, Alison M; Eperjesi, Thomas J; Plappert, Theodore J; Yushkevich, Paul A; Hung, Judy; Mariani, Massimo A; Khabbaz, Kamal R; Gleason, Thomas G; Mahmood, Feroze; Acker, Michael A; Woo, Y Joseph; Cheung, Albert T; Gillespie, Matthew J; Jackson, Benjamin M; Gorman, Joseph H; Gorman, Robert C

    2016-09-01

    Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. Intraoperative transesophageal 2-dimensional echocardiography and 3-dimensional echocardiography were performed in 50 patients undergoing undersized annuloplasty for ischemic mitral regurgitation. Two-dimensional echocardiography annular diameter and tethering parameters were measured in the apical 2- and 4-chamber views. A customized protocol was used to assess 3-dimensional annular geometry and regional leaflet tethering. Recurrence (grade ≥2) was assessed with 2-dimensional transthoracic echocardiography at 6 months. Preoperative 2- and 3-dimensional annular geometry were similar in all patients with ischemic mitral regurgitation. Preoperative 2- and 3-dimensional leaflet tethering were significantly higher in patients with recurrence (n = 13) when compared with patients without recurrence (n = 37). Multivariate logistic regression revealed preoperative 2-dimensional echocardiography posterior tethering angle as an independent predictor of recurrence with an optimal cutoff value of 32.0° (area under the curve, 0.81; 95% confidence interval, 0.68-0.95; P = .002) and preoperative 3-dimensional echocardiography P3 tethering angle as an independent predictor of recurrence with an optimal cutoff value of 29.9° (area under the curve, 0.92; 95% confidence interval, 0.84-1.00; P < .001). The predictive value of the 3-dimensional geometric multivariate model can be augmented by adding basal aneurysm/dyskinesis (area under the curve, 0.94; 95% confidence interval, 0.87-1.00; P < .001). Preoperative 3-dimensional echocardiography P3 tethering angle is a stronger predictor of ischemic mitral regurgitation recurrence after annuloplasty than preoperative 2-dimensional echocardiography posterior

  1. [Reformatting 3-dimensional medical images. Application to MRI and scanners].

    PubMed

    Cuchet, E; Lambert, F; Derosier, C

    1994-04-01

    Several kinds of images, each giving a different information, are now available to radiologists. The MRI images have excellent contrast resolution and enable soft tissues to be differentiated, but they do not distinguish structures with low water content, notably air and bone, whereas these are easily recognized by CT. The aim of this study is to present a simple, entirely radiologist-supervised method to examine the radiological data of any patient, obtained from several kinds of images. MRI is performed using a GEMS Signa, 1.5 Tesla, 4.9 version magnet. Acquisitions are T1- or T2-weighted spin-echo or gradient sequences, with a 256 or 512 matrix, on axial sections, with of without contrast injection. CT is performed using a GEMS Hi Speed scanner. Acquisitions are obtained on a 512 matrix and with a "Soft" or "Bone" filter, without contrast injection. The two series of sections are transmitted, through an Etherne network, to a Sun console where the two corresponding volumes are reconstructed on a GEMS Voxtol by means of a 3-dimensional soft ware for image treatment. At least 3 couples define the rotation and translation required for one of the two volumes to reset it in the guide mark of the other. The soft ware then looks for the best transformation, in terms of least square, between the two 3-dimensional volumes. The calculation demands only a few seconds. One of the two objects is then recalculated in the guide mark of the other. The cursor positioned by the user on any point of the object is linked to a second cursor which will automatically position itself on the corresponding point of the other object. The accuracy obtained (about one millimeter) is specified by the soft ware which indicates how to improve resetting. In addition to its teaching value, this superimposition image can help in the diagnosis and can be used for surgical stimulation because it is possible to mix the images. This mixing gives access to a new type of imaging, since the images spared

  2. Cost-effective, personalized, 3D-printed liver model for preoperative planning before laparoscopic liver hemihepatectomy for colorectal cancer metastases.

    PubMed

    Witowski, Jan Sylwester; Pędziwiatr, Michał; Major, Piotr; Budzyński, Andrzej

    2017-01-31

    Three-dimensional (3D) printing for preoperative planning has been intensively developed in the recent years. However, the implementation of these solutions in hospitals is still difficult due to high costs, extremely expensive industrial-grade printers, and software that is difficult to obtain and learn along with a lack of a defined process. This paper presents a cost-effective technique of preparing 3D-printed liver models that preserves the shape and all of the structures, including the vessels and the tumor, which in the present case is colorectal liver metastasis. The patient's computed tomography scans were used for the separation and visualization of virtual 3D anatomical structures. Those elements were transformed into stereolithographic files and subsequently printed on a desktop 3D printer. The multipart structure was assembled and filled with silicone. The patient underwent subsequent laparoscopic right hemihepatectomy. The entire process is described step-by-step, and only free-to-use and mostly open-source software was used. As a result, a transparent, full-sized liver model with visible vessels and colorectal metastasis was created for under $150, which-taking into account 3D printer prices-is much cheaper than models presented in previous research papers. The increased accessibility of 3D models for physicians before complex laparoscopic surgical procedures such as hepatic resections could lead to beneficial breakthroughs in these sophisticated surgeries, as many reports show that these models reduce operative time and improve short term outcomes.

  3. Heat Transfer Modeling of a Charring Material Using Isoconversional Kinetics (Pre-Print)

    DTIC Science & Technology

    2016-09-28

    been considered in the modeling of heat transfer and pyrolysis in a charring material. The isoconversional approach is appealing due to the use of...Aerospace Group, Brigham City, UT, 84302 Abstract An isoconversional modeling approach has been considered in the modeling of heat transfer and pyrolysis ...these materials often lose mass as they pyrolyze (char) internally, causing pyrolysis gases to escape through the porous char structure. As a result

  4. Complex crustal structures: their 3D grav/mag modelling and 3D printing

    NASA Astrophysics Data System (ADS)

    Götze, Hans-Jürgen; Schmidt, Sabine; Menzel, Peter

    2017-04-01

    Our new techniques for modelling and visualization are user-friendly because they are highly interactive, ideally real-time and topology conserving and can be used for both flat and spherical models in 3D. These are important requirements for joint inversion for gravity and magnetic modelling of fields and their derivatives, constrained by seismic and structural input from independent data sources. A borehole tool for magnetic and gravity modelling will also be introduced. We are already close to satisfying the demand of treating several geophysical methods in a single model for subsurface evaluation purposes and aim now for fulfilling most of the constraints: consistency of modelling results and measurements and geological plausibility as well. For 3D modelling, polyhedrons built by triangles are used. All elements of the gravity and magnetic tensors can be included. In the modelling interface, after geometry changes the effect on the model is quickly updated because only the changed triangles have to be recalculated. Because of the triangular model structure, our approach can handle complex structures very well and flexible (e.g. overhangs of salt domes or plumes). For regional models, the use of spherical geometries and calculations is necessary and available. 3D visualization is performed with a 3D-printer (Ultimaker 2) and gives new insights into even rather complicated Earth subsurface structures. Inversion can either be run over the whole model, but typically it is used in smaller parts of the model, helping to solve local problems and/or proving/disproving local hypotheses. The basic principles behind this interactive approach are high performance optimized algorithms (CMA-ES: Covariance-matrix-adoption-evolution-strategy). The efficiency of the algorithm is rather good in terms of stable convergence due to topological model validity. Potential field modelling is always influenced by edge effects. To avoid this, a simple but very robust method has been

  5. A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics.

    PubMed

    Knoops, Paul G M; Biglino, Giovanni; Hughes, Alun D; Parker, Kim H; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

    2017-07-01

    A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the

  6. In vitro measurement of muscle volume with 3-dimensional ultrasound.

    PubMed

    Delcker, A; Walker, F; Caress, J; Hunt, C; Tegeler, C

    1999-05-01

    The aim was to test the accuracy of muscle volume measurements with a new 3-dimensional (3-D) ultrasound system, which allows a freehand scanning of the transducer with an improved quality of the ultrasound images and therefore the outlines of the muscles. Five resected cadaveric hand muscles were insonated and the muscle volumes calculated by 3-D reconstructions of the acquired 2-D ultrasound sections. Intra-reader, inter-reader and follow-up variability were calculated, as well as the volume of the muscle tissue measured by water displacement. In the results, 3-D ultrasound and water displacement measurements showed an average deviation of 10.1%; Data of 3-D ultrasound measurements were: intra-reader variability 2.8%; inter-reader variability 2.4% and follow-up variability 2.3%. 3-D measurements of muscle volume are valid and reliable. Serial sonographic measurements of muscle may be able to quantitate changes in muscle volume that occur in disease and recovery.

  7. Thermal crosstalk in 3-dimensional RRAM crossbar array.

    PubMed

    Sun, Pengxiao; Lu, Nianduan; Li, Ling; Li, Yingtao; Wang, Hong; Lv, Hangbing; Liu, Qi; Long, Shibing; Liu, Su; Liu, Ming

    2015-08-27

    High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application. The Joule heat generated inside the RRAM device will determine the switching behavior itself, and for dense memory arrays, the temperature surrounding may lead to a consequent resistance degradation of neighboring devices. In this work, thermal crosstalk effect and scaling potential under thermal effect in 3D RRAM crossbar array are systematically investigated. It is revealed that the reset process is dominated by transient thermal effect in 3D RRAM array. More importantly, thermal crosstalk phenomena could deteriorate device retention performance and even lead to data storage state failure from LRS (low resistance state) to HRS (high resistance state) of the disturbed RRAM cell. In addition, the resistance state degradation will be more serious with continuously scaling down the feature size. Possible methods for alleviating thermal crosstalk effect while further advancing the scaling potential are also provided and verified by numerical simulation.

  8. Thermal crosstalk in 3-dimensional RRAM crossbar array

    NASA Astrophysics Data System (ADS)

    Sun, Pengxiao; Lu, Nianduan; Li, Ling; Li, Yingtao; Wang, Hong; Lv, Hangbing; Liu, Qi; Long, Shibing; Liu, Su; Liu, Ming

    2015-08-01

    High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application. The Joule heat generated inside the RRAM device will determine the switching behavior itself, and for dense memory arrays, the temperature surrounding may lead to a consequent resistance degradation of neighboring devices. In this work, thermal crosstalk effect and scaling potential under thermal effect in 3D RRAM crossbar array are systematically investigated. It is revealed that the reset process is dominated by transient thermal effect in 3D RRAM array. More importantly, thermal crosstalk phenomena could deteriorate device retention performance and even lead to data storage state failure from LRS (low resistance state) to HRS (high resistance state) of the disturbed RRAM cell. In addition, the resistance state degradation will be more serious with continuously scaling down the feature size. Possible methods for alleviating thermal crosstalk effect while further advancing the scaling potential are also provided and verified by numerical simulation.

  9. Thermal crosstalk in 3-dimensional RRAM crossbar array

    PubMed Central

    Sun, Pengxiao; Lu, Nianduan; Li, Ling; Li, Yingtao; Wang, Hong; Lv, Hangbing; Liu, Qi; Long, Shibing; Liu, Su; Liu, Ming

    2015-01-01

    High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application. The Joule heat generated inside the RRAM device will determine the switching behavior itself, and for dense memory arrays, the temperature surrounding may lead to a consequent resistance degradation of neighboring devices. In this work, thermal crosstalk effect and scaling potential under thermal effect in 3D RRAM crossbar array are systematically investigated. It is revealed that the reset process is dominated by transient thermal effect in 3D RRAM array. More importantly, thermal crosstalk phenomena could deteriorate device retention performance and even lead to data storage state failure from LRS (low resistance state) to HRS (high resistance state) of the disturbed RRAM cell. In addition, the resistance state degradation will be more serious with continuously scaling down the feature size. Possible methods for alleviating thermal crosstalk effect while further advancing the scaling potential are also provided and verified by numerical simulation. PMID:26310537

  10. The first 3-dimensional assemblies of organotin-functionalized polyanions.

    PubMed

    Piedra-Garza, Luis Fernando; Reinoso, Santiago; Dickman, Michael H; Sanguineti, Michael M; Kortz, Ulrich

    2009-08-21

    Reaction of the (CH(3))(2)Sn(2+) electrophile toward trilacunary [A-alpha-XW(9)O(34)](n-) Keggin polytungstates (X = P(V), As(V), Si(IV)) with guanidinium as templating-cation resulted in the isostructural compounds Na[C(NH(2))(3)](2)[{(CH(3))(2)Sn(H(2)O)}(3)(A-alpha-PW(9)O(34))] x 9 H(2)O (1), Na[C(NH(2))(3)](2)[{(CH(3))(2)Sn(H(2)O)}(3)(A-alpha-AsW(9)O(34))] x 8 H(2)O (2) and Na(2)[C(NH(2))(3)](2)[{(CH(3))(2)Sn(H(2)O)}(3)(A-alpha-SiW(9)O(34))] x 10 H(2)O (3). Compounds 1-3 constitute the first 3-dimensional assemblies of organotin-functionalized polyanions, as well as the first example of a dimethyltin-containing tungstosilicate in the case of 3, and they show a similar chiral architecture based on tetrahedrally-arranged {(CH(3))(2)Sn}(3)(A-alpha-XW(9)O(34)) monomeric building-blocks connected via intermolecular Sn-O=W bridges regardless of the size and/or charge of the heteroatom.

  11. Finger Character Recognition Using 3-Dimensional Template Matching

    NASA Astrophysics Data System (ADS)

    Higashiyama, Kazuhiro; Ono, Satoshi; Wang, Yu; Nakayama, Shigeru

    This paper proposes a method for Japanese finger character recognition, using a 3-dimensional (3D) scanner. A hand is a complex dexterous manipulator, evolved to be more complex than any other animals. The hand, being capable of making many different complex shapes, it is ideal for communicating using gestures. The recognition of a whole language, such as the Japanese finger characters, requires the differentiation of subtle similar positioning of each digit. To know the exact 3D position of the hand's digits and overall shape, data gloves had been developed, but these are inconvenient to use. 2D image recognition systems struggle with recreating the 3D information. To capture the 3D information, the proposed method uses a 3D scanner, and then makes matches with 3D templates representing each unique character. Experimental results show that the proposed method recognizes a greater number of characters than existing 2D-based systems with recognition accuracy, on average of 93% for 9 testees, and a peak of over 98% for 4 of them.

  12. The International Intercomparison of 3-Dimensional Radiation Codes

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    I3RC (International Intercomparison of 3-dimensional Radiation Codes) has as its primary goal to compare a wide variety of three-dimensional (3D) radiative transfer methods applied to Earth's atmosphere, with a few selected cloud fields as input, and a few selected radiative quantities as output. Phases 1 and 2 are now complete, and participants represented institutions in Canada, France, Germany, Russia, the United Kingdom, and the USA, who met for two workshops in Tucson, Arizona USA, and compared results from 5 cloud fields of varying complexity, beginning with simplified atmosphere and surface, and proceeding to more realistic cases. Phase 3 is now underway, focusing on improvement and sharing of 3D radiation code, aided by working groups on "Approximations" and "Open Source". The "Approximations" group has so far focused on diffusive approximate methods in an attempt to gain advantages in execution time, and also to advance the understanding of 3D radiation processes. The "Open Source" subgroup is developing a Monte Carlo radiative transfer toolkit that makes state-of-the-art techniques available to a wide range of users. Activities of both subgroups are further explained at the I3RC website http://i3rc.gsfc.nasa.gov. Participants in 13RC are forming a 3D Working Group under the auspices of the International Radiation Commission, and will meet for this and related activities at a workshop in Tucson in November 2002.

  13. 3-Dimensional Facial Analysis—Facing Precision Public Health

    PubMed Central

    Baynam, Gareth; Bauskis, Alicia; Pachter, Nicholas; Schofield, Lyn; Verhoef, Hedwig; Palmer, Richard L.; Kung, Stefanie; Helmholz, Petra; Ridout, Michael; Walker, Caroline E.; Hawkins, Anne; Goldblatt, Jack; Weeramanthri, Tarun S.; Dawkins, Hugh J. S.; Molster, Caron M.

    2017-01-01

    Precision public health is a new field driven by technological advances that enable more precise descriptions and analyses of individuals and population groups, with a view to improving the overall health of populations. This promises to lead to more precise clinical and public health practices, across the continuum of prevention, screening, diagnosis, and treatment. A phenotype is the set of observable characteristics of an individual resulting from the interaction of a genotype with the environment. Precision (deep) phenotyping applies innovative technologies to exhaustively and more precisely examine the discrete components of a phenotype and goes beyond the information usually included in medical charts. This form of phenotyping is a critical component of more precise diagnostic capability and 3-dimensional facial analysis (3DFA) is a key technological enabler in this domain. In this paper, we examine the potential of 3DFA as a public health tool, by viewing it against the 10 essential public health services of the “public health wheel,” developed by the US Centers for Disease Control. This provides an illustrative framework to gage current and emergent applications of genomic technologies for implementing precision public health. PMID:28443272

  14. An electro-dynamic 3-dimensional vibration test bed for engineering testing

    NASA Astrophysics Data System (ADS)

    Saadatzi, Mohammadsadegh; Saadatzi, Mohammad Nasser; Ahmed, Riaz; Banerjee, Sourav

    2017-04-01

    Primary objective of the work is to design, fabrication and testing of a 3-dimensional Mechanical vibration test bed. Vibration testing of engineering prototype devices in mechanical and industrial laboratories is essential to understand the response of the envisioned model under physical excitation conditions. Typically, two sorts of vibration sources are available in physical environment, acoustical and mechanical. Traditionally, test bed to simulate unidirectional acoustic or mechanical vibration is used in engineering laboratories. However, a device may encounter multiple uncoupled and/or coupled loading conditions. Hence, a comprehensive test bed in essential that can simulate all possible sorts of vibration conditions. In this article, an electrodynamic vibration exciter is presented which is capable of simulating 3-dimensional uncoupled (unidirectional) and coupled excitation, in mechanical environments. The proposed model consists of three electromagnetic shakers (for mechanical excitation). A robust electrical control circuit is designed to regulate the components of the test bed through a self-developed Graphical User Interface. Finally, performance of the test bed is tested and validated using commercially available piezoelectric sensors.

  15. Manipulating 3D-Printed and Paper Models Enhances Student Understanding of Viral Replication

    ERIC Educational Resources Information Center

    Couper, Lisa; Johannes, Kristen; Powers, Jackie; Silberglitt, Matt; Davenport, Jodi

    2016-01-01

    Understanding key concepts in molecular biology requires reasoning about molecular processes that are not directly observable and, as such, presents a challenge to students and teachers. We ask whether novel interactive physical models and activities can help students understand key processes in viral replication. Our 3D tangible models are…

  16. Manipulating 3D-Printed and Paper Models Enhances Student Understanding of Viral Replication

    ERIC Educational Resources Information Center

    Couper, Lisa; Johannes, Kristen; Powers, Jackie; Silberglitt, Matt; Davenport, Jodi

    2016-01-01

    Understanding key concepts in molecular biology requires reasoning about molecular processes that are not directly observable and, as such, presents a challenge to students and teachers. We ask whether novel interactive physical models and activities can help students understand key processes in viral replication. Our 3D tangible models are…

  17. Analytical modeling of multi-layered Printed Circuit Board dedicated to electronic component thermal characterization

    NASA Astrophysics Data System (ADS)

    Monier-Vinard, Eric; Laraqi, Najib; Dia, Cheikh-Tidiane; Nguyen, Minh-Nhat; Bissuel, Valentin

    2015-01-01

    Electronic components are continuously getting smaller and embedding more and more powered functions which exacerbate the temperature rise in component/board interconnect areas. For still air conditions, the heat spreading of the component power is mainly done through the surrounding metallic planes of its electronic board. Their design optimization is henceforth mandatory to control the temperature and to preserve component reliability. To allow the electronic designer to early analyze the limits of the power dissipation of miniaturized devices, an analytical model of a multi-layered electronic board was established with the purpose to assess the validity of conventional board modeling approach. For decades, numerous authors have been promoting a homogenous single layer model that summed up the layers of the board using effective orthotropic thermal properties. The derived compact model depends on thermal properties approximation which is commonly based on parallel conduction model given a linear rule of mixture. The work presents the thermal behavior comparison of a detailed multi-layer representation to its deducted compact model for an extensive set of variable parameters, such as heat transfer coefficients, effective thermal conductivities calculation models, number of trace layers, trace coverage or source size. The results highlight the fact that the conventional practices for PCB modeling can dramatically underestimate source temperatures when their size is getting very small.

  18. Impact of Animated Spokes-Characters in Print Direct-to-Consumer Prescription Drug Advertising: An Elaboration Likelihood Model Approach.

    PubMed

    Bhutada, Nilesh S; Rollins, Brent L; Perri, Matthew

    2017-04-01

    A randomized, posttest-only online survey study of adult U.S. consumers determined the advertising effectiveness (attitude toward ad, brand, company, spokes-characters, attention paid to the ad, drug inquiry intention, and perceived product risk) of animated spokes-characters in print direct-to-consumer (DTC) advertising of prescription drugs and the moderating effects of consumers' involvement. Consumers' responses (n = 490) were recorded for animated versus nonanimated (human) spokes-characters in a fictitious DTC ad. Guided by the elaboration likelihood model, data were analyzed using a 2 (spokes-character type: animated/human) × 2 (involvement: high/low) factorial multivariate analysis of covariance (MANCOVA). The MANCOVA indicated significant main effects of spokes-character type and involvement on the dependent variables after controlling for covariate effects. Of the several ad effectiveness variables, consumers only differed on their attitude toward the spokes-characters between the two spokes-character types (specifically, more favorable attitudes toward the human spokes-character). Apart from perceived product risk, high-involvement consumers reacted more favorably to the remaining ad effectiveness variables compared to the low-involvement consumers, and exhibited significantly stronger drug inquiry intentions during their next doctor visit. Further, the moderating effect of consumers' involvement was not observed (nonsignificant interaction effect between spokes-character type and involvement).

  19. 3D Printed Block Copolymer Nanostructures

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E.

    2015-01-01

    The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this…

  20. 3D Printed Block Copolymer Nanostructures

    ERIC Educational Resources Information Center

    Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E.

    2015-01-01

    The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this…

  1. Organ printing: promises and challenges.

    PubMed

    Mironov, Vladimir; Kasyanov, Vladimir; Drake, Christopher; Markwald, Roger R

    2008-01-01

    Organ printing or biomedical application of rapid prototyping, also defined as additive layer-by-layer biomanufacturing, is an emerging transforming technology that has potential for surpassing traditional solid scaffold-based tissue engineering. Organ printing has certain advantages: it is an automated approach that offers a pathway for scalable reproducible mass production of tissue engineered products; it allows a precised simultaneous 3D positioning of several cell types; it enables creation tissue with a high level of cell density; it can solve the problem of vascularization in thick tissue constructs; finally, organ printing can be done in situ. The ultimate goal of organ-printing technology is to fabricate 3D vascularized functional living human organs suitable for clinical implantation. The main practical outcomes of organ-printing technology are industrial scalable robotic biofabrication of complex human tissues and organs, automated tissue-based in vitro assays for clinical diagnostics, drug discovery and drug toxicity, and complex in vitro models of human diseases. This article describes conceptual framework and recent developments in organ-printing technology, outlines main technological barriers and challenges, and presents potential future practical applications.

  2. On estimation of perceived mottling prior to printing

    NASA Astrophysics Data System (ADS)

    Sadovnikov, Albert; Lensu, Lasse; Kälviäinen, Heikki

    2008-01-01

    Print mottle is one of the most significant defects in modern offset printing influencing overall print quality. Mottling can be defined as undesired unevenness in perceived print density. Previous research in the field considered designing and improving perception models for evaluating print mottle. Mottle has traditionally been evaluated by estimating the reflectance variation in the print. In our work, we present an approach of estimating mottling effect prior to printing. Our experiments included imaging non printed media under various lighting conditions, printing the samples with sheet fed offset printing and imaging afterwards. For the preprint examinations we used a set of preprint images and for the outcome testing we used high resolution scans. For the set of papers used in experiment only uncoated mechanical speciality paper showed a good chance of print mottle prediction. Other tested paper types had a low correlation between non-printed and printed images. The achieved results allow predicting the amount of mottling on the final print using preprint area images for a certain paper type. Current experiment settings suited well for uncoated paper, but for the coated samples other settings need to be tested. The results show that the estimation can be made on the coarse scale and for better results extra parameters will be required, i.e., paper type, coating, printing process in question.

  3. Endoscopic skull base training using 3D printed models with pre-existing pathology.

    PubMed

    Narayanan, Vairavan; Narayanan, Prepageran; Rajagopalan, Raman; Karuppiah, Ravindran; Rahman, Zainal Ariff Abdul; Wormald, Peter-John; Van Hasselt, Charles Andrew; Waran, Vicknes

    2015-03-01

    Endoscopic base of skull surgery has been growing in acceptance in the recent past due to improvements in visualisation and micro instrumentation as well as the surgical maturing of early endoscopic skull base practitioners. Unfortunately, these demanding procedures have a steep learning curve. A physical simulation that is able to reproduce the complex anatomy of the anterior skull base provides very useful means of learning the necessary skills in a safe and effective environment. This paper aims to assess the ease of learning endoscopic skull base exposure and drilling techniques using an anatomically accurate physical model with a pre-existing pathology (i.e., basilar invagination) created from actual patient data. Five models of a patient with platy-basia and basilar invagination were created from the original MRI and CT imaging data of a patient. The models were used as part of a training workshop for ENT surgeons with varying degrees of experience in endoscopic base of skull surgery, from trainees to experienced consultants. The surgeons were given a list of key steps to achieve in exposing and drilling the skull base using the simulation model. They were then asked to list the level of difficulty of learning these steps using the model. The participants found the models suitable for learning registration, navigation and skull base drilling techniques. All participants also found the deep structures to be accurately represented spatially as confirmed by the navigation system. These models allow structured simulation to be conducted in a workshop environment where surgeons and trainees can practice to perform complex procedures in a controlled fashion under the supervision of experts.

  4. 3D printing the pterygopalatine fossa: a negative space model of a complex structure.

    PubMed

    Bannon, Ross; Parihar, Shivani; Skarparis, Yiannis; Varsou, Ourania; Cezayirli, Enis

    2017-08-30

    The pterygopalatine fossa is one of the most complex anatomical regions to understand. It is poorly visualized in cadaveric dissection and most textbooks rely on schematic depictions. We describe our approach to creating a low-cost, 3D model of the pterygopalatine fossa, including its associated canals and foramina, using an affordable "desktop" 3D printer. We used open source software to create a volume render of the pterygopalatine fossa from axial slices of a head computerised tomography scan. These data were then exported to a 3D printer to produce an anatomically accurate model. The resulting 'negative space' model of the pterygopalatine fossa provides a useful and innovative aid for understanding the complex anatomical relationships of the pterygopalatine fossa. This model was designed primarily for medical students; however, it will also be of interest to postgraduates in ENT, ophthalmology, neurosurgery, and radiology. The technical process described may be replicated by other departments wishing to develop their own anatomical models whilst incurring minimal costs.

  5. The 3-dimensional numerical simulation of artificially altitude-triggered negative lightning

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Chen, Bin; Shi, Lihua; Chen, Qiang

    2013-03-01

    A 3-dimensional numerical model for artificially altitude-triggered negative lightning is developed based on an analytic thunderstorm model and the Dielectric Breakdown Model (DBM). Two major parameters are concerned, they are the thundercloud electric field and the length of the nylon wire which isolates the triggering wire from the ground. A few groups of contrast numerical experiments are done to study their effects on the success rates of altitude-triggered lightning. It is found that the success rates of altitude-triggered lightning increase when the thundercloud electric field enhances or the length of the nylon wire increases. Another interesting phenomenon is that the upward positive leader is always initiated earlier than the downward negative leader in either case.

  6. 3D-printed phantom for the characterization of non-uniform rotational distortion (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hohert, Geoffrey; Pahlevaninezhad, Hamid; Lee, Anthony; Lane, Pierre M.

    2016-03-01

    Endoscopic catheter-based imaging systems that employ a 2-dimensional rotary or 3-dimensional rotary-pullback scanning mechanism require constant angular velocity at the distal tip to ensure correct angular registration of the collected signal. Non-uniform rotational distortion (NURD) - often present due to a variety of mechanical issues - can result in inconsistent position and velocity profiles at the tip, limiting the accuracy of any measurements. Since artifacts like NURD are difficult to identify and characterize during tissue imaging, phantoms with well-defined patterns have been used to quantify position and/or velocity error. In this work we present a fast, versatile, and cost-effective method for making fused deposition modeling 3D printed phantoms for identifying and quantifying NURD errors along an arbitrary user-defined pullback path. Eight evenly-spaced features are present at the same orientation at all points on the path such that deviations from expected geometry can be quantified for the imaging catheter. The features are printed vertically and then folded together around the path to avoid issues with printer head resolution. This method can be adapted for probes of various diameters and for complex imaging paths with multiple bends. We demonstrate imaging using the 3D printed phantoms with a 1mm diameter rotary-pullback OCT catheter and system as a means of objectively evaluating the mechanical performance of similarly constructed probes.

  7. Video Based Sensor for Tracking 3-Dimensional Targets

    NASA Technical Reports Server (NTRS)

    Howard, R. T.; Book, Michael L.; Bryan, Thomas C.

    2000-01-01

    Video-Based Sensor for Tracking 3-Dimensional Targets The National Aeronautics and Space Administration's (NASAs) Marshall Space Flight Center (MSFC) has been developing and testing video-based sensors for automated spacecraft guidance for several years, and the next generation of video sensor will have tracking rates up to 100 Hz and will be able to track multiple reflectors and targets. The Video Guidance Sensor (VGS) developed over the past several years has performed well in testing and met the objective of being used as the terminal guidance sensor for an automated rendezvous and capture system. The first VGS was successfully tested in closed-loop 3-degree-of-freedom (3- DOF) tests in 1989 and then in 6-DOF open-loop tests in 1992 and closed-loop tests in 1993-4. Development and testing continued, and in 1995 approval was given to test the VGS in an experiment on the Space Shuttle. The VGS flew in 1997 and in 1998, performing well for both flights. During the development and testing before, during, and after the flight experiments, numerous areas for improvement were found. The VGS was developed with a sensor head and an electronics box, connected by cables. The VGS was used in conjunction with a target that had wavelength-filtered retro-reflectors in a specific pattern, The sensor head contained the laser diodes, video camera, and heaters and coolers. The electronics box contained a frame grabber, image processor, the electronics to control the components in the sensor head, the communications electronics, and the power supply. The system works by sequentially firing two different wavelengths of laser diodes at the target and processing the two images. Since the target only reflects one wavelength, it shows up well in one image and not at all in the other. Because the target's dimensions are known, the relative positions and attitudes of the target and the sensor can be computed from the spots reflected from the target. The system was designed to work from I

  8. The 3-dimensional grid: a novel approach to stereoelectroencephalography.

    PubMed

    Munyon, Charles; Sweet, Jennifer; Luders, Hans; Lhatoo, Samden; Miller, Jonathan

    2015-03-01

    Successful surgical treatment of epilepsy requires accurate definition of areas of ictal onset and eloquent brain. Although invasive monitoring can help, subdural grids cannot sample sulci or subcortical tissue; traditional stereoelectroencephalography depth electrodes are usually placed too far apart to provide sufficient resolution for mapping. To report a strategy of depth electrode placement in a dense array to allow precise anatomic localization of epileptic and eloquent cortex. Twenty patients with medically intractable epilepsy either poorly localized or found to arise adjacent to eloquent areas underwent placement of arrays of depth electrodes into and around the putative area of seizure onset with the use of framed stereotaxy. Each array consisted of a "grid" of parallel electrodes in a rectangular pattern with 1 cm between entry sites. In a subset of patients, a few electrodes were placed initially, with additional electrodes placed in a second stage. Trajectories were modified to avoid cortical vessels defined on magnetic resonance imaging. Patients were monitored for 4 to 21 days to establish the precise location of seizure onset. Stimulation was performed to map cortical and subcortical eloquent regions. Electrode locations were coregistered for frameless stereotaxy during subsequent resection of seizure focus. Two hundred fifty-four electrodes were implanted. Discrete regions of seizure onset and functional cortex were identified, which were used during resection to remove epileptogenic tissue while preserving eloquent areas. There were no hemorrhagic or infectious complications; no patient suffered permanent neurological deficit. The 3-dimensional intraparenchymal grid is useful for identifying the location and extent of epileptic and eloquent brain.

  9. A new preclinical 3-dimensional agarose colony formation assay.

    PubMed

    Kajiwara, Yoshinori; Panchabhai, Sonali; Levin, Victor A

    2008-08-01

    The evaluation of new drug treatments and combination treatments for gliomas and other cancers requires a robust means to interrogate wide dose ranges and varying times of drug exposure without stain-inactivation of the cells (colonies). To this end, we developed a 3-dimensional (3D) colony formation assay that makes use of GelCount technology, a new cell colony counter for gels and soft agars. We used U251MG, SNB19, and LNZ308 glioma cell lines and MiaPaCa pancreas adenocarcinoma and SW480 colon adenocarcinoma cell lines. Colonies were grown in a two-tiered agarose that had 0.7% agarose on the bottom and 0.3% agarose on top. We then studied the effects of DFMO, carboplatin, and SAHA over a 3-log dose range and over multiple days of drug exposure. Using GelCount we approximated the area under the curve (AUC) of colony volumes as the sum of colony volumes (microm2xOD) in each plate to calculate IC50 values. Adenocarcinoma colonies were recognized by GelCount scanning at 3-4 days, while it took 6-7 days to detect glioma colonies. The growth rate of MiaPaCa and SW480 cells was rapid, with 100 colonies counted in 5-6 days; glioma cells grew more slowly, with 100 colonies counted in 9-10 days. Reliable log dose versus AUC curves were observed for all drugs studied. In conclusion, the GelCount method that we describe is more quantitative than traditional colony assays and allows precise study of drug effects with respect to both dose and time of exposure using fewer culture plates.

  10. Distance stereotest using a 3-dimensional monitor for adult subjects.

    PubMed

    Kim, Jongshin; Yang, Hee Kyung; Kim, Youngmin; Lee, Byoungho; Hwang, Jeong-Min

    2011-06-01

    To evaluate the validity and test-retest reliability of a contour-based 3-dimensional (3-D) monitor distance stereotest (distance 3-D stereotest) and to measure the maximum horizontal disparity that can be fused with disparity vergence for determining the largest measurable disparity of true stereopsis. Observational case series. Sixty-four normal adult subjects (age range, 23 to 39 years) were recruited. Contour-based circles (crossed disparity, 5000 to 20 seconds of arc; Microsoft Visual Studio C(++) 6.0; Microsoft, Inc, Seattle, Washington, USA) were generated on a 3-D monitor (46-inch stereoscopic display) using polarization glasses and were presented to subjects with normal binocularity at 3 m. While the position of the stimulus changed among 4 possible locations, the subjects were instructed to press the corresponding position of the stimulus on a keypad. The results with the new distance 3-D stereotest were compared with those from the distance Randot stereotest. The results of the distance 3-D stereotest and the distance Randot stereotests were identical in 64% and within 1 disparity level in 97% of normal adults. Scores obtained with the 2 tests showed a statistically significant correlation (r = 0.324, P = .009). The half-width of the 95% limit of agreement was 0.47 log seconds of arc (1.55 octaves) using the distance 3-D stereotest--similar to or better than that obtained with conventional distance stereotests. The maximum binocular disparity that can be fused with vergence was 1828 ± 794 seconds of arc (range, 4000 to 500). The distance 3-D stereotest showed good concordance with the distance Randot stereotest and relatively good test-retest reliability, supporting the validity of the distance 3-D stereotest. The normative data set obtained from the present study can serve as a useful reference for quantitative assessment of a wide range of binocular sensory abnormalities. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. 3-Dimensional shear wave elastography of breast lesions

    PubMed Central

    Chen, Ya-ling; Chang, Cai; Zeng, Wei; Wang, Fen; Chen, Jia-jian; Qu, Ning

    2016-01-01

    Abstract Color patterns of 3-dimensional (3D) shear wave elastography (SWE) is a promising method in differentiating tumoral nodules recently. This study was to evaluate the diagnostic accuracy of color patterns of 3D SWE in breast lesions, with special emphasis on coronal planes. A total of 198 consecutive women with 198 breast lesions (125 malignant and 73 benign) were included, who underwent conventional ultrasound (US), 3D B-mode, and 3D SWE before surgical excision. SWE color patterns of Views A (transverse), T (sagittal), and C (coronal) were determined. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC) were calculated. Distribution of SWE color patterns was significantly different between malignant and benign lesions (P = 0.001). In malignant lesions, “Stiff Rim” was significantly more frequent in View C (crater sign, 60.8%) than in View A (51.2%, P = 0.013) and View T (54.1%, P = 0.035). AUC for combination of “Crater Sign” and conventional US was significantly higher than View A (0.929 vs 0.902, P = 0.004) and View T (0.929 vs 0.907, P = 0.009), and specificity significantly increased (90.4% vs 78.1%, P = 0.013) without significant change in sensitivity (85.6% vs 88.0%, P = 0.664) as compared with conventional US. In conclusion, combination of conventional US with 3D SWE color patterns significantly increased diagnostic accuracy, with “Crater Sign” in coronal plane of the highest value. PMID:27684820

  12. Crossover from 2-dimensional to 3-dimensional aggregations of clusters on square lattice substrates

    NASA Astrophysics Data System (ADS)

    Cheng, Yi; Zhu, Yu-Hong; Pan, Qi-Fa; Yang, Bo; Tao, Xiang-Ming; Ye, Gao-Xiang

    2015-11-01

    A Monte Carlo study on the crossover from 2-dimensional to 3-dimensional aggregations of clusters is presented. Based on the traditional cluster-cluster aggregation (CCA) simulation, a modified growth model is proposed. The clusters (including single particles and their aggregates) diffuse with diffusion step length l (1 ≤ l ≤ 7) and aggregate on a square lattice substrate. If the number of particles contained in a cluster is larger than a critical size sc, the particles at the edge of the cluster have a possibility to jump onto the upper layer, which results in the crossover from 2-dimensional to 3-dimensional aggregations. Our simulation results are in good agreement with the experimental findings. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374082 and 11074215), the Science Foundation of Zhejiang Province Department of Education, China (Grant No. Y201018280), the Fundamental Research Funds for Central Universities, China (Grant No. 2012QNA3010), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100101110005).

  13. Endothelial cells assemble into a 3-dimensional prevascular network in a bone tissue engineering construct.

    PubMed

    Rouwkema, Jeroen; de Boer, Jan; Van Blitterswijk, Clemens A

    2006-09-01

    To engineer tissues with clinically relevant dimensions, one must overcome the challenge of rapidly creating functional blood vessels to supply cells with oxygen and nutrients and to remove waste products. We tested the hypothesis that endothelial cells, cocultured with osteoprogenitor cells, can organize into a prevascular network in vitro. When cultured in a spheroid coculture model with human mesenchymal stem cells, human umbilical vein endothelial cells (HUVECs) form a 3-dimensional prevascular network within 10 days of in vitro culture. The formation of the prevascular network was promoted by seeding 2% or fewer HUVECs. Moreover, the addition of endothelial cells resulted in a 4-fold upregulation of the osteogenic marker alkaline phosphatase. The addition of mouse embryonic fibroblasts did not result in stabilization of the prevascular network. Upon implantation, the prevascular network developed further and structures including lumen could be seen regularly. However, anastomosis with the host vasculature was limited. We conclude that endothelial cells are able to form a 3-dimensional (3D) prevascular network in vitro in a bone tissue engineering setting. This finding is a strong indication that in vitro prevascularization is a promising strategy to improve implant vascularization in bone tissue engineering.

  14. Identifying Affordances of 3D Printed Tangible Models for Understanding Core Biological Concepts

    ERIC Educational Resources Information Center

    Davenport, Jodi L.; Silberglitt, Matt; Boxerman, Jonathan; Olson, Arthur

    2014-01-01

    3D models derived from actual molecular structures have the potential to transform student learning in biology. We share findings related to our research questions: 1) what types of interactions with a protein folding kit promote specific learning objectives?, and 2) what features of the instructional environment (e.g., peer interactions, teacher…

  15. Identifying Affordances of 3D Printed Tangible Models for Understanding Core Biological Concepts

    ERIC Educational Resources Information Center

    Davenport, Jodi L.; Silberglitt, Matt; Boxerman, Jonathan; Olson, Arthur

    2014-01-01

    3D models derived from actual molecular structures have the potential to transform student learning in biology. We share findings related to our research questions: 1) what types of interactions with a protein folding kit promote specific learning objectives?, and 2) what features of the instructional environment (e.g., peer interactions, teacher…

  16. Analysis of the mechanical response of biomimetic materials with highly oriented microstructures through 3D printing, mechanical testing and modeling.

    PubMed

    de Obaldia, Enrique Escobar; Jeong, Chanhue; Grunenfelder, Lessa Kay; Kisailus, David; Zavattieri, Pablo

    2015-08-01

    Many biomineralized organisms have evolved highly oriented nanostructures to perform specific functions. One key example is the abrasion-resistant rod-like microstructure found in the radular teeth of Chitons (Cryptochiton stelleri), a large mollusk. The teeth consist of a soft core and a hard shell that is abrasion resistant under extreme mechanical loads with which they are subjected during the scraping process. Such remarkable mechanical properties are achieved through a hierarchical arrangement of nanostructured magnetite rods surrounded with α-chitin. We present a combined biomimetic approach in which designs were analyzed with additive manufacturing, experiments, analytical and computational models to gain insights into the abrasion resistance and toughness of rod-like microstructures. Staggered configurations of hard hexagonal rods surrounded by thin weak interfacial material were printed, and mechanically characterized with a cube-corner indenter. Experimental results demonstrate a higher contact resistance and stiffness for the staggered alignments compared to randomly distributed fibrous materials. Moreover, we reveal an optimal rod aspect ratio that lead to an increase in the site-specific properties measured by indentation. Anisotropy has a significant effect (up to 50%) on the Young's modulus in directions parallel and perpendicular to the longitudinal axis of the rods, and 30% on hardness and fracture toughness. Optical microscopy suggests that energy is dissipated in the form of median cracks when the load is parallel to the rods and lateral cracks when the load is perpendicular to the rods. Computational models suggest that inelastic deformation of the rods at early stages of indentation can vary the resistance to penetration. As such, we found that the mechanical behavior of the system is influenced by interfacial shear strain which influences the lateral load transfer and therefore the spread of damage. This new methodology can help to elucidate

  17. Palm print image processing with PCNN

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Zhao, Xianhong

    2010-08-01

    Pulse coupled neural networks (PCNN) is based on Eckhorn's model of cat visual cortex, and imitate mammals visual processing, and palm print has been found as a personal biological feature for a long history. This inspired us with the combination of them: a novel method for palm print processing is proposed, which includes pre-processing and feature extraction of palm print image using PCNN; then the feature of palm print image is used for identifying. Our experiment shows that a verification rate of 87.5% can be achieved at ideal condition. We also find that the verification rate decreases duo to rotate or shift of palm.

  18. High-Resolution Seismic Velocity and Attenuation Models of Eastern Tibet and Adjacent Regions (Post Print)

    DTIC Science & Technology

    2012-06-04

    Basin. QLg and QPg models have been determined using a Reverse Two- station/event Method, which shows a high seismic attenuation zone along the...been determined using a Reverse Two-station/event Method, which shows a high seismic attenuation zone along the Kunlun belt. We have also observed...Like Pn and body wave results, low velocity anomalies occur across and within major strike-slip fault zones in the Qiangtang and Songpan-Ganzi

  19. Active origami by 4D printing

    NASA Astrophysics Data System (ADS)

    Ge, Qi; Dunn, Conner K.; Qi, H. Jerry; Dunn, Martin L.

    2014-09-01

    Recent advances in three dimensional (3D) printing technology that allow multiple materials to be printed within each layer enable the creation of materials and components with precisely controlled heterogeneous microstructures. In addition, active materials, such as shape memory polymers, can be printed to create an active microstructure within a solid. These active materials can subsequently be activated in a controlled manner to change the shape or configuration of the solid in response to an environmental stimulus. This has been termed 4D printing, with the 4th dimension being the time-dependent shape change after the printing. In this paper, we advance the 4D printing concept to the design and fabrication of active origami, where a flat sheet automatically folds into a complicated 3D component. Here we print active composites with shape memory polymer fibers precisely printed in an elastomeric matrix and use them as intelligent active hinges to enable origami folding patterns. We develop a theoretical model to provide guidance in selecting design parameters such as fiber dimensions, hinge length, and programming strains and temperature. Using the model, we design and fabricate several active origami components that assemble from flat polymer sheets, including a box, a pyramid, and two origami airplanes. In addition, we directly print a 3D box with active composite hinges and program it to assume a temporary flat shape that subsequently recovers to the 3D box shape on demand.

  20. Characterization and modeling of screen-printed metal insulator semiconductor tunnel junctions for integrated bypass functionality in crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Thaidigsmann, Benjamin; Lohmüller, Elmar; Fertig, Fabian; Clement, Florian; Wolf, Andreas

    2013-06-01

    This work investigates sintered, screen-printed silver contacts on lowly doped p-type silicon with different intermediate dielectric layer systems using scanning electron microscopy and dark current-voltage measurements. The data reveal electron tunneling through a thin insulating layer as the most probable transport mechanism. A model based on Fowler-Nordheim and direct tunneling is presented that allows for the description of reverse current-voltage characteristics and the extraction of effective contact properties. The investigated screen-printed metal insulator semiconductor structures are proposed as solar cell integrated bypass that reduces the risk of hot spot generation and power loss during partial shading of a module. Furthermore, the integrated bypass approach enables the fabrication of solar cells from silicon material that tends to show early breakdown of the p-n-junction.

  1. Effect of dental technician disparities on the 3-dimensional accuracy of definitive casts.

    PubMed

    Emir, Faruk; Piskin, Bulent; Sipahi, Cumhur

    2017-03-01

    Studies that evaluated the effect of dental technician disparities on the accuracy of presectioned and postsectioned definitive casts are lacking. The purpose of this in vitro study was to evaluate the accuracy of presectioned and postsectioned definitive casts fabricated by different dental technicians by using a 3-dimensional computer-aided measurement method. An arch-shaped metal master model consisting of 5 abutments resembling prepared mandibular incisors, canines, and first molars and with a 6-degree total angle of convergence was designed and fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) technology. Complete arch impressions were made (N=110) from the master model, using polyvinyl siloxane (PVS) and delivered to 11 dental technicians. Each technician fabricated 10 definitive casts with dental stone, and the obtained casts were numbered. All casts were sectioned, and removable dies were obtained. The master model and the presectioned and postsectioned definitive casts were digitized with an extraoral scanner, and the virtual master model and virtual presectioned and postsectioned definitive casts were obtained. All definitive casts were compared with the master model by using computer-aided measurements, and the 3-dimensional accuracy of the definitive casts was determined with best fit alignment and represented in color-coded maps. Differences were analyzed using univariate analyses of variance, and the Tukey honest significant differences post hoc tests were used for multiple comparisons (α=.05). The accuracy of presectioned and postsectioned definitive casts was significantly affected by dental technician disparities (P<.001). The largest dimensional changes were detected in the anterior abutments of both of the definitive casts. The changes mostly occurred in the mesiodistal dimension (P<.001). Within the limitations of this in vitro study, the accuracy of presectioned and postsectioned definitive casts is susceptible

  2. Putting 3D modelling and 3D printing into practice: virtual surgery and preoperative planning to reconstruct complex post-traumatic skeletal deformities and defects

    PubMed Central

    Tetsworth, Kevin; Block, Steve; Glatt, Vaida

    2017-01-01

    3D printing technology has revolutionized and gradually transformed manufacturing across a broad spectrum of industries, including healthcare. Nowhere is this more apparent than in orthopaedics with many surgeons already incorporating aspects of 3D modelling and virtual procedures into their routine clinical practice. As a more extreme application, patient-specific 3D printed titanium truss cages represent a novel approach for managing the challenge of segmental bone defects. This review illustrates the potential indications of this innovative technique using 3D printed titanium truss cages in conjunction with the Masquelet technique. These implants are custom designed during a virtual surgical planning session with the combined input of an orthopaedic surgeon, an orthopaedic engineering professional and a biomedical design engineer. The ability to 3D model an identical replica of the original intact bone in a virtual procedure is of vital importance when attempting to precisely reconstruct normal anatomy during the actual procedure. Additionally, other important factors must be considered during the planning procedure, such as the three-dimensional configuration of the implant. Meticulous design is necessary to allow for successful implantation through the planned surgical exposure, while being aware of the constraints imposed by local anatomy and prior implants. This review will attempt to synthesize the current state of the art as well as discuss our personal experience using this promising technique. It will address implant design considerations including the mechanical, anatomical and functional aspects unique to each case. PMID:28220752

  3. Putting 3D modelling and 3D printing into practice: virtual surgery and preoperative planning to reconstruct complex post-traumatic skeletal deformities and defects.

    PubMed

    Tetsworth, Kevin; Block, Steve; Glatt, Vaida

    2017-01-01

    3D printing technology has revolutionized and gradually transformed manufacturing across a broad spectrum of industries, including healthcare. Nowhere is this more apparent than in orthopaedics with many surgeons already incorporating aspects of 3D modelling and virtual procedures into their routine clinical practice. As a more extreme application, patient-specific 3D printed titanium truss cages represent a novel approach for managing the challenge of segmental bone defects. This review illustrates the poten