Dosimetric comparison between proton beam therapy and photon radiation therapy for locally advanced non-small cell lung cancer.

PubMed

Wu, Chen-Ta; Motegi, Atsushi; Motegi, Kana; Hotta, Kenji; Kohno, Ryosuke; Tachibana, Hidenobu; Kumagai, Motoki; Nakamura, Naoki; Hojo, Hidehiro; Niho, Seiji; Goto, Koichi; Akimoto, Tetsuo

2016-08-10

To assess the feasibility of proton beam therapy for the patients with locally advanced non-small lung cancer. The dosimetry was analyzed retrospectively to calculate the doses to organs at risk, such as the lung, heart, esophagus and spinal cord. A dosimetric comparison between proton beam therapy and dummy photon radiotherapy (three-dimensional conformal radiotherapy) plans was performed. Dummy intensity-modulated radiotherapy plans were also generated for the patients for whom curative three-dimensional conformal radiotherapy plans could not be generated. Overall, 33 patients with stage III non-small cell lung cancer were treated with proton beam therapy between December 2011 and August 2014. The median age of the eligible patients was 67 years (range: 44-87 years). All the patients were treated with chemotherapy consisting of cisplatin/vinorelbine or carboplatin. The median prescribed dose was 60 GyE (range: 60-66 GyE). The mean normal lung V20 GyE was 23.6% (range: 14.9-32%), and the mean normal lung dose was 11.9 GyE (range: 6.0-19 GyE). The mean esophageal V50 GyE was 25.5% (range: 0.01-63.6%), the mean heart V40 GyE was 13.4% (range: 1.4-29.3%) and the mean maximum spinal cord dose was 40.7 GyE (range: 22.9-48 GyE). Based on dummy three-dimensional conformal radiotherapy planning, 12 patients were regarded as not being suitable for radical thoracic three-dimensional conformal radiotherapy. All the dose parameters of proton beam therapy, except for the esophageal dose, were lower than those for the dummy three-dimensional conformal radiotherapy plans. In comparison to the intensity-modulated radiotherapy plan, proton beam therapy also achieved dose reduction in the normal lung. None of the patients experienced grade 4 or worse non-hematological toxicities. Proton beam therapy for patients with stage III non-small cell lung cancer was feasible and was superior to three-dimensional conformal radiotherapy for several dosimetric parameters. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Government review of the Mod-2 wind turbine (as-built)

NASA Technical Reports Server (NTRS)

Johnson, W. R.; Birchenough, A. G.; Linscott, B. S.; Reagan, J. R.; Sirocky, P. J.; Sizemore, R. L.; Sullivan, T. L.; Holeman, R. H.

1985-01-01

The findings and recommendations of the Government committee formed to conduct an as-built review of the three Mod-2 wind turbine units at Goldendale, Washington are given. The purpose of the review was to identify any critical deficiencies in machine components that could result in failure, and to recommend any necessary corrective action before resuming safe machine operation. The review concluded that one of the deficiencies identified would preclude planned attended or unattended operation, provided that certain corrective actions were implemented.

Symmetry-Breaking Phase Transition without a Peierls Instability in Conducting Monoatomic Chains

NASA Astrophysics Data System (ADS)

Blumenstein, C.; Schäfer, J.; Morresi, M.; Mietke, S.; Matzdorf, R.; Claessen, R.

2011-10-01

The one-dimensional (1D) model system Au/Ge(001), consisting of linear chains of single atoms on a surface, is scrutinized for lattice instabilities predicted in the Peierls paradigm. By scanning tunneling microscopy and electron diffraction we reveal a second-order phase transition at 585 K. It leads to charge ordering with transversal and vertical displacements and complex interchain correlations. However, the structural phase transition is not accompanied by the electronic signatures of a charge density wave, thus precluding a Peierls instability as origin. Instead, this symmetry-breaking transition exhibits three-dimensional critical behavior. This reflects a dichotomy between the decoupled 1D electron system and the structural elements that interact via the substrate. Such substrate-mediated coupling between the wires thus appears to have been underestimated also in related chain systems.

Computer-assisted surgical planning and automation of laser delivery systems

NASA Astrophysics Data System (ADS)

Zamorano, Lucia J.; Dujovny, Manuel; Dong, Ada; Kadi, A. Majeed

1991-05-01

This paper describes a 'real time' surgical treatment planning interactive workstation, utilizing multimodality imaging (computer tomography, magnetic resonance imaging, digital angiography) that has been developed to provide the neurosurgeon with two-dimensional multiplanar and three-dimensional 'display' of a patient's lesion.

Application of Mathematical and Three-Dimensional Computer Modeling Tools in the Planning of Processes of Fuel and Energy Complexes

NASA Astrophysics Data System (ADS)

Aksenova, Olesya; Nikolaeva, Evgenia; Cehlár, Michal

2017-11-01

This work aims to investigate the effectiveness of mathematical and three-dimensional computer modeling tools in the planning of processes of fuel and energy complexes at the planning and design phase of a thermal power plant (TPP). A solution for purification of gas emissions at the design development phase of waste treatment systems is proposed employing mathematical and three-dimensional computer modeling - using the E-nets apparatus and the development of a 3D model of the future gas emission purification system. Which allows to visualize the designed result, to select and scientifically prove economically feasible technology, as well as to ensure the high environmental and social effect of the developed waste treatment system. The authors present results of a treatment of planned technological processes and the system for purifying gas emissions in terms of E-nets. using mathematical modeling in the Simulink application. What allowed to create a model of a device from the library of standard blocks and to perform calculations. A three-dimensional model of a system for purifying gas emissions has been constructed. It allows to visualize technological processes and compare them with the theoretical calculations at the design phase of a TPP and. if necessary, make adjustments.

Use of 3D printer technology to facilitate surgical correction of a complex vascular anomaly with esophageal entrapment in a dog.

PubMed

Dundie, A; Hayes, G; Scrivani, P; Campoy, L; Fletcher, D; Ash, K; Oxford, E; Moïse, N S

2017-04-01

A 10 week old female intact Staffordshire terrier was presented with a total of five congenital cardio-thoracic vascular anomalies consisting of a patent ductus arteriosus (PDA) with an aneurysmic dilation, pulmonic stenosis, persistent right aortic arch, aberrant left subclavian artery and persistent left cranial vena cava. These abnormalities were identified with a combination of echocardiogram and computed tomography angiography (CTA). The abnormalities were associated with esophageal entrapment, regurgitation, and volume overload of the left heart with left atrial and ventricular enlargement. A 2 cm diameter aneurysmic dilation at the junction of the PDA, right aortic arch and aberrant left subclavian artery presented an unusual surgical challenge and precluded simple circumferential ligation and transection of the structure. A full scale three dimensional model of the heart and vasculature was constructed from the CTA and plasma sterilized. The model was used preoperatively to facilitate surgical planning and enhance intraoperative communication and coordination between the surgical and anesthesia teams. Intraoperatively the model facilitated spatial orientation, atraumatic vascular dissection, instrument sizing and positioning. A thoracoabdominal stapler was used to close the PDA aneurysm prior to transection. At the four-month postoperative follow-up the patient was doing well. This is the first reported application of new imaging and modeling technology to enhance surgical planning when approaching correction of complex cardiovascular anomalies in a dog. Copyright © 2016 Elsevier B.V. All rights reserved.

[Rapid prototyping: a very promising method].

PubMed

Haverman, T M; Karagozoglu, K H; Prins, H-J; Schulten, E A J M; Forouzanfar, T

2013-03-01

Rapid prototyping is a method which makes it possible to produce a three-dimensional model based on two-dimensional imaging. Various rapid prototyping methods are available for modelling, such as stereolithography, selective laser sintering, direct laser metal sintering, two-photon polymerization, laminated object manufacturing, three-dimensional printing, three-dimensional plotting, polyjet inkjet technology,fused deposition modelling, vacuum casting and milling. The various methods currently being used in the biomedical sector differ in production, materials and properties of the three-dimensional model which is produced. Rapid prototyping is mainly usedforpreoperative planning, simulation, education, and research into and development of bioengineering possibilities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manem, V; Paganetti, H

Purpose: Evaluate the excess relative risk (ERR) induced by photons and protons in each voxel of the lung, and display it as a three-dimensional map, known as the ERRM (i.e. excess relative risk map) along with the dose distribution map. In addition, we also study the effect of variations in the linear energy transfer (LET) distribution on ERRM for a given proton plan. Methods: The excess relative risk due to radiation is estimated using the initiation-inactivation-proliferation formalism. This framework accounts for three biological phenomenon: mutation induction, cell kill and proliferation. Cell kill and mutation induction are taken as a functionmore » of LET using experimental data. LET distributions are calculated using a Monte Carlo algorithm. ERR is then estimated for each voxel in the organ, and displayed as a three dimensional carcinogenic map. Results: The differences in the ERR’s between photons and protons is seen from the three-dimensional ERR map. In addition, we also varied the LET of a proton plan and observed the differences in the corresponding ERR maps demonstrating variations in the ERR maps depend on features of a proton plan. Additionally, our results suggest that any two proton plans that have the same integral dose does not necessarily imply identical ERR maps, and these changes are due to the variations in the LET distribution map. Conclusion: Clinically, it is important to have a three dimensional display of biological end points. This study is an effort to introduce 3D ERR maps into the treatment planning workflow for certain sites such as pediatric head and neck tumors.« less

26 CFR 1.410(b)-6 - Excludable employees.

Code of Federal Regulations, 2010 CFR

2010-04-01

... conditions with respect to the plan are excludable employees. In addition, if the plan being tested applies... agreement, nonprofessionals as well as professionals. Thus, no employees covered by such an agreement are... governmental entities who are precluded from being eligible employees under a section 401(k) plan by reason of...

77 FR 46009 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-02

... and Hazardous Substances Pollution Contingency Plan; National Priorities List: Partial Deletion of the... Substances Pollution Contingency Plan (NCP). The EPA and the State of Maine, through the Maine Department of... preclude future actions under Superfund. This partial deletion pertains to all Site media (including soil...

Engineering Surface Critical Behavior of (2 +1 )-Dimensional O(3) Quantum Critical Points

NASA Astrophysics Data System (ADS)

Ding, Chengxiang; Zhang, Long; Guo, Wenan

2018-06-01

Surface critical behavior (SCB) refers to the singularities of physical quantities on the surface at the bulk phase transition. It is closely related to and even richer than the bulk critical behavior. In this work, we show that three types of SCB universality are realized in the dimerized Heisenberg models at the (2 +1 )-dimensional O(3) quantum critical points by engineering the surface configurations. The ordinary transition happens if the surface is gapped in the bulk disordered phase, while the gapless surface state generally leads to the multicritical special transition, even though the latter is precluded in classical phase transitions because the surface is in the lower critical dimension. An extraordinary transition is induced by the ferrimagnetic order on the surface of the staggered Heisenberg model, in which the surface critical exponents violate the results of the scaling theory and thus seriously challenge our current understanding of extraordinary transitions.

Three-Dimensional Printing as an Interdisciplinary Communication Tool: Preparing for Removal of a Giant Renal Tumor and Atrium Neoplastic Mass.

PubMed

Golab, Adam; Slojewski, Marcin; Brykczynski, Miroslaw; Lukowiak, Magdalena; Boehlke, Marek; Matias, Daniel; Smektala, Tomasz

2016-08-22

Three-dimensional (3D) printing involves preparing 3D objects from a digital model. These models can be used to plan and practice surgery. We used 3D printing to plan for a rare complicated surgery involving the removal of a renal tumor and neoplastic mass, which reached the heart atrium. A printed kidney model was an essential element of communication for physicians with different specializations.

Preoperative planning and real-time assisted navigation by three-dimensional individual digital model in partial nephrectomy with three-dimensional laparoscopic system.

PubMed

Wang, Dongwen; Zhang, Bin; Yuan, Xiaobin; Zhang, Xuhui; Liu, Chen

2015-09-01

To evaluate the feasibility and effectiveness of preoperative planning and real-time assisted surgical navigation for three-dimensional laparoscopic partial nephrectomy under the guidance of three-dimensional individual digital model (3D-IDM) created using three-dimensional medical image reconstructing and guiding system (3D-MIRGS). Between May 2012 and February 2014, 44 patients with cT1 renal tumors underwent retroperitoneal laparoscopic partial nephrectomy (LPN) using a three-dimensional laparoscopic system. The 3D-IDMs were created using the 3D-MIRGS in 21 patients (3D-MIRGS group) between February 2013 and February 2014. After preoperative planning, operations were real-time assisted using composite 3D-IDMs, which were fused with two-dimensional retrolaparoscopic images. The remaining 23 patients underwent surgery without 3D-MIRGS between May 2012 and February 2013; 14 of these patients were selected as a control group. Preoperative aspects and dimensions used for an anatomical score, "radius; exophytic/endophytic; nearness; anterior/posterior; location" nephrometry score, tumor size, operative time (OT), segmental renal artery clamping (SRAC) time, estimated blood loss (EBL), postoperative hospitalization, the preoperative serum creatinine level and ipsilateral glomerular filtration rate (GFR), as well as postoperative 6-month data were compared between groups. All the SRAC procedures were technically successful, and each targeted tumor was excised completely; final pathological margin results were negative. The OT was shorter (159.0 vs. 193.2 min; p < 0.001), and EBL (148.1 vs. 176.1 mL; p < 0.001) was reduced in the 3D-MIRGS group compared with controls. No statistically significant differences in SRAC time or postoperative hospitalization were found between the groups. Neither group showed any statistically significant increases in serum creatinine level or decreases in ipsilateral GFR postoperatively. Preoperative planning and real-time assisted surgical navigation using the 3D-IDM reconstructed from 3D-MIRGS and combined with the 3D laparoscopic system can facilitate LPN and result in precise SRAC and accurate excision of tumor that is both effective and safe.

The current status and future prospects of computer-assisted hip surgery.

PubMed

Inaba, Yutaka; Kobayashi, Naomi; Ike, Hiroyuki; Kubota, So; Saito, Tomoyuki

2016-03-01

The advances in computer assistance technology have allowed detailed three-dimensional preoperative planning and simulation of preoperative plans. The use of a navigation system as an intraoperative assistance tool allows more accurate execution of the preoperative plan, compared to manual operation without assistance of the navigation system. In total hip arthroplasty using CT-based navigation, three-dimensional preoperative planning with computer software allows the surgeon to determine the optimal angle of implant placement at which implant impingement is unlikely to occur in the range of hip joint motion necessary for daily activities of living, and to determine the amount of three-dimensional correction for leg length and offset. With the use of computer navigation for intraoperative assistance, the preoperative plan can be precisely executed. In hip osteotomy using CT-based navigation, the navigation allows three-dimensional preoperative planning, intraoperative confirmation of osteotomy sites, safe performance of osteotomy even under poor visual conditions, and a reduction in exposure doses from intraoperative fluoroscopy. Positions of the tips of chisels can be displayed on the computer monitor during surgery in real time, and staff other than the operator can also be aware of the progress of surgery. Thus, computer navigation also has an educational value. On the other hand, its limitations include the need for placement of trackers, increased radiation exposure from preoperative CT scans, and prolonged operative time. Moreover, because the position of a bone fragment cannot be traced after osteotomy, methods to find its precise position after its movement need to be developed. Despite the need to develop methods for the postoperative evaluation of accuracy for osteotomy, further application and development of these systems are expected in the future. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Tumor resection at the pelvis using three-dimensional planning and patient-specific instruments: a case series.

PubMed

Jentzsch, Thorsten; Vlachopoulos, Lazaros; Fürnstahl, Philipp; Müller, Daniel A; Fuchs, Bruno

2016-09-21

Sarcomas are associated with a relatively high local recurrence rate of around 30 % in the pelvis. Inadequate surgical margins are the most important reason. However, obtaining adequate margins is particularly difficult in this anatomically demanding region. Recently, three-dimensional (3-D) planning, printed models, and patient-specific instruments (PSI) with cutting blocks have been introduced to improve the precision during surgical tumor resection. This case series illustrates these modern 3-D tools in pelvic tumor surgery. The first consecutive patients with 3-D-planned tumor resection around the pelvis were included in this retrospective study at a University Hospital in 2015. Detailed information about the clinical presentation, imaging techniques, preoperative planning, intraoperative surgical procedures, and postoperative evaluation is provided for each case. The primary outcome was tumor-free resection margins as assessed by a postoperative computed tomography (CT) scan of the specimen. The secondary outcomes were precision of preoperative planning and complications. Four patients with pelvic sarcomas were included in this study. The mean follow-up was 7.8 (range, 6.0-9.0) months. The combined use of preoperative planning with 3-D techniques, 3-D-printed models, and PSI for osteotomies led to higher precision (maximal (max) error of 0.4 centimeters (cm)) than conventional 3-D planning and freehand osteotomies (max error of 2.8 cm). Tumor-free margins were obtained where measurable (n = 3; margins were not assessable in a patient with curettage). Two insufficiency fractures were noted postoperatively. Three-dimensional planning as well as the intraoperative use of 3-D-printed models and PSI are valuable for complex sarcoma resection at the pelvis. Three-dimensionally printed models of the patient anatomy may help visualization and precision. PSI with cutting blocks help perform very precise osteotomies for adequate resection margins.

Touching proteins with virtual bare hands - Visualizing protein-drug complexes and their dynamics in self-made virtual reality using gaming hardware

NASA Astrophysics Data System (ADS)

Ratamero, Erick Martins; Bellini, Dom; Dowson, Christopher G.; Römer, Rudolf A.

2018-06-01

The ability to precisely visualize the atomic geometry of the interactions between a drug and its protein target in structural models is critical in predicting the correct modifications in previously identified inhibitors to create more effective next generation drugs. It is currently common practice among medicinal chemists while attempting the above to access the information contained in three-dimensional structures by using two-dimensional projections, which can preclude disclosure of useful features. A more accessible and intuitive visualization of the three-dimensional configuration of the atomic geometry in the models can be achieved through the implementation of immersive virtual reality (VR). While bespoke commercial VR suites are available, in this work, we present a freely available software pipeline for visualising protein structures through VR. New consumer hardware, such as the uc(HTC Vive) and the uc(Oculus Rift) utilized in this study, are available at reasonable prices. As an instructive example, we have combined VR visualization with fast algorithms for simulating intramolecular motions of protein flexibility, in an effort to further improve structure-led drug design by exposing molecular interactions that might be hidden in the less informative static models. This is a paradigmatic test case scenario for many similar applications in computer-aided molecular studies and design.

Touching proteins with virtual bare hands : Visualizing protein-drug complexes and their dynamics in self-made virtual reality using gaming hardware.

PubMed

Ratamero, Erick Martins; Bellini, Dom; Dowson, Christopher G; Römer, Rudolf A

2018-06-07

The ability to precisely visualize the atomic geometry of the interactions between a drug and its protein target in structural models is critical in predicting the correct modifications in previously identified inhibitors to create more effective next generation drugs. It is currently common practice among medicinal chemists while attempting the above to access the information contained in three-dimensional structures by using two-dimensional projections, which can preclude disclosure of useful features. A more accessible and intuitive visualization of the three-dimensional configuration of the atomic geometry in the models can be achieved through the implementation of immersive virtual reality (VR). While bespoke commercial VR suites are available, in this work, we present a freely available software pipeline for visualising protein structures through VR. New consumer hardware, such as the HTC VIVE and the OCULUS RIFT utilized in this study, are available at reasonable prices. As an instructive example, we have combined VR visualization with fast algorithms for simulating intramolecular motions of protein flexibility, in an effort to further improve structure-led drug design by exposing molecular interactions that might be hidden in the less informative static models. This is a paradigmatic test case scenario for many similar applications in computer-aided molecular studies and design.

Towards building a team of intelligent robots

NASA Technical Reports Server (NTRS)

Varanasi, Murali R.; Mehrotra, R.

1987-01-01

Topics addressed include: collision-free motion planning of multiple robot arms; two-dimensional object recognition; and pictorial databases (storage and sharing of the representations of three-dimensional objects).

Sentinel Lymph Node Biopsy: Quantification of Lymphedema Risk Reduction

DTIC Science & Technology

2006-10-01

dimensional internal mammary lymphoscintigraphy: implications for radiation therapy treatment planning for breast carcinoma. Int J Radiat Oncol Biol Phys...techniques based on conventional photon beams, intensity modulated photon beams and proton beams for therapy of intact breast. Radiother Oncol. Feb...Harris JR. Three-dimensional internal mammary lymphoscintigraphy: implications for radiation therapy treatment planning for breast carcinoma. Int J

Timing of three-dimensional virtual treatment planning of orthognathic surgery: a prospective single-surgeon evaluation on 350 consecutive cases.

PubMed

Swennen, Gwen R J

2014-11-01

The purpose of this article is to evaluate the timing for three-dimensional (3D) virtual treatment planning of orthognathic surgery in the daily clinical routine. A total of 350 consecutive patients were included in this study. All patients were scanned following the standardized "Triple CBCT Scan Protocol" in centric relation. Integrated 3D virtual planning and actual surgery were performed by the same surgeon in all patients. Although clinically acceptable, still software improvements especially toward 3D virtual occlusal definition are mandatory to make 3D virtual planning of orthognathic surgery less time-consuming and more user-friendly to the clinician. Copyright © 2014 Elsevier Inc. All rights reserved.

Accuracy assessment of surgical planning and three-dimensional-printed patient-specific guides for orthopaedic osteotomies.

PubMed

Sys, Gwen; Eykens, Hannelore; Lenaerts, Gerlinde; Shumelinsky, Felix; Robbrecht, Cedric; Poffyn, Bart

2017-06-01

This study analyses the accuracy of three-dimensional pre-operative planning and patient-specific guides for orthopaedic osteotomies. To this end, patient-specific guides were compared to the classical freehand method in an experimental setup with saw bones in two phases. In the first phase, the effect of guide design and oscillating versus reciprocating saws was analysed. The difference between target and performed cuts was quantified by the average distance deviation and average angular deviations in the sagittal and coronal planes for the different osteotomies. The results indicated that for one model osteotomy, the use of guides resulted in a more accurate cut when compared to the freehand technique. Reciprocating saws and slot guides improved accuracy in all planes, while oscillating saws and open guides lead to larger deviations from the planned cut. In the second phase, the accuracy of transfer of the planning to the surgical field with slot guides and a reciprocating saw was assessed and compared to the classical planning and freehand cutting method. The pre-operative plan was transferred with high accuracy. Three-dimensional-printed patient-specific guides improve the accuracy of osteotomies and bony resections in an experimental setup compared to conventional freehand methods. The improved accuracy is related to (1) a detailed and qualitative pre-operative plan and (2) an accurate transfer of the planning to the operation room with patient-specific guides by an accurate guidance of the surgical tools to perform the desired cuts.

Feasibility of tomotherapy to reduce normal lung and cardiac toxicity for distal esophageal cancer compared to three-dimensional radiotherapy.

PubMed

Nguyen, Nam P; Krafft, Shane P; Vinh-Hung, Vincent; Vos, Paul; Almeida, Fabio; Jang, Siyoung; Ceizyk, Misty; Desai, Anand; Davis, Rick; Hamilton, Russ; Modarresifar, Homayoun; Abraham, Dave; Smith-Raymond, Lexie

2011-12-01

To compare the effectiveness of tomotherapy and three-dimensional (3D) conformal radiotherapy to spare normal critical structures (spinal cord, lungs, and ventricles) from excessive radiation in patients with distal esophageal cancers. A retrospective dosimetric study of nine patients who had advanced gastro-esophageal (GE) junction cancer (7) or thoracic esophageal cancer (2) extending into the distal esophagus. Two plans were created for each of the patients. A three-dimensional plan was constructed with either three (anteroposterior, right posterior oblique, and left posterior oblique) or four (right anterior oblique, left anterior oblique, right posterior oblique, and left posterior oblique) fields. The second plan was for tomotherapy. Doses were 45 Gy to the PTV with an integrated boost of 5 Gy for tomotherapy. Mean lung dose was respectively 7.4 and 11.8 Gy (p=0.004) for tomotherapy and 3D plans. Corresponding values were 12.4 and 18.3 Gy (p=0.006) for cardiac ventricles. Maximum spinal cord dose was respectively 31.3 and 37.4 Gy (p < 0.007) for tomotherapy and 3D plans. Homogeneity index was two for both groups. Compared to 3D conformal radiotherapy, tomotherapy decreased significantly the amount of normal tissue irradiated and may reduce treatment toxicity for possible dose escalation in future prospective studies. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Modeling Cometary Coma with a Three Dimensional, Anisotropic Multiple Scattering Distributed Processing Code

NASA Technical Reports Server (NTRS)

Luchini, Chris B.

1997-01-01

Development of camera and instrument simulations for space exploration requires the development of scientifically accurate models of the objects to be studied. Several planned cometary missions have prompted the development of a three dimensional, multi-spectral, anisotropic multiple scattering model of cometary coma.

Measuring Three-Dimensional Thorax Motion Via Biplane Radiographic Imaging: Technique and Preliminary Results.

PubMed

Baumer, Timothy G; Giles, Joshua W; Drake, Anne; Zauel, Roger; Bey, Michael J

2016-01-01

Measures of scapulothoracic motion are dependent on accurate imaging of the scapula and thorax. Advanced radiographic techniques can provide accurate measures of scapular motion, but the limited 3D imaging volume of these techniques often precludes measurement of thorax motion. To overcome this, a thorax coordinate system was defined based on the position of rib pairs and then compared to a conventional sternum/spine-based thorax coordinate system. Alignment of the rib-based coordinate system was dependent on the rib pairs used, with the rib3:rib4 pairing aligned to within 4.4 ± 2.1 deg of the conventional thorax coordinate system.

Four-dimensional computed tomography-based treatment planning for intensity-modulated radiation therapy and proton therapy for distal esophageal cancer.

PubMed

Zhang, Xiaodong; Zhao, Kuai-le; Guerrero, Thomas M; McGuire, Sean E; Yaremko, Brian; Komaki, Ritsuko; Cox, James D; Hui, Zhouguang; Li, Yupeng; Newhauser, Wayne D; Mohan, Radhe; Liao, Zhongxing

2008-09-01

To compare three-dimensional (3D) and four-dimensional (4D) computed tomography (CT)-based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. The IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Compared with IMRT, median lung volumes exposed to 5, 10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%, 5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%, 8.4%, 5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index [CI], 1.99) and greater irradiation of the heart (heart-V40, 41.8%) compared with the IMRT plan(CI, 1.55, heart-V40, 35.7%) or the three-beam proton plan (CI, 1.46, heart-V40, 27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas filling. Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses.

Three-Dimensional Path Planning for Uninhabited Combat Aerial Vehicle Based on Predator-Prey Pigeon-Inspired Optimization in Dynamic Environment.

PubMed

Zhang, Bo; Duan, Haibin

2017-01-01

Three-dimension path planning of uninhabited combat aerial vehicle (UCAV) is a complicated optimal problem, which mainly focused on optimizing the flight route considering the different types of constrains under complex combating environment. A novel predator-prey pigeon-inspired optimization (PPPIO) is proposed to solve the UCAV three-dimension path planning problem in dynamic environment. Pigeon-inspired optimization (PIO) is a new bio-inspired optimization algorithm. In this algorithm, map and compass operator model and landmark operator model are used to search the best result of a function. The prey-predator concept is adopted to improve global best properties and enhance the convergence speed. The characteristics of the optimal path are presented in the form of a cost function. The comparative simulation results show that our proposed PPPIO algorithm is more efficient than the basic PIO, particle swarm optimization (PSO), and different evolution (DE) in solving UCAV three-dimensional path planning problems.

Reproducibility of three dimensional digital preoperative planning for the osteosynthesis of distal radius fractures.

PubMed

Yoshii, Yuichi; Kusakabe, Takuya; Akita, Kenichi; Tung, Wen Lin; Ishii, Tomoo

2017-12-01

A three-dimensional (3D) digital preoperative planning system for the osteosynthesis of distal radius fractures was developed for clinical practice. To assess the usefulness of the 3D planning for osteosynthesis, we evaluated the reproducibility of the reduction shapes and selected implants in the patients with distal radius fractures. Twenty wrists of 20 distal radius fracture patients who underwent osteosynthesis using volar locking plates were evaluated. The 3D preoperative planning was performed prior to each surgery. Four surgeons conducted the surgeries. The surgeons performed the reduction and the placement of the plate while comparing images between the preoperative plan and fluoroscopy. Preoperative planning and postoperative reductions were compared by measuring volar tilt and radial inclination of the 3D images. Intra-class correlation coefficients (ICCs) of the volar tilt and radial inclination were evaluated. For the implant choices, the ICCs for the screw lengths between the preoperative plan and the actual choices were evaluated. The ICCs were 0.644 (p < 0.01) and 0.625 (p < 0.01) for the volar tilt and radial inclination in the 3D measurements, respectively. The planned size of plate was used in all of the patients. The ICC for the screw length between preoperative planning and actual choice was 0.860 (p < 0.01). Good reproducibility for the reduction shape and excellent reproducibility for the implant choices were achieved using 3D preoperative planning for distal radius fracture. Three-dimensional digital planning was useful to visualize the reduction process and choose a proper implant for distal radius fractures. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2646-2651, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Craniospinal Irradiation for Trilateral Retinoblastoma Following Ocular Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, Lawrence B.; Bentel, Gunilla; Sherouse, George W.

A case study is presented. Craniospinal radiotherapy and a three-field pineal boost for trilateral retinoblastoma were delivered to a patient previously irradiated for ocular retinoblastoma. The availability of CT-based three-dimensional treatment planning provided the capability of identifying the previously irradiated volume as a three-dimensional anatomic structure and of designing a highly customized set of treatment beams that minimized reirradiation of that volume.

Novel Treatment Planning of Hemimandibular Hyperplasia by the Use of Three-Dimensional Computer-Aided-Design and Computer-Aided-Manufacturing Technologies.

PubMed

Hatamleh, Muhanad M; Yeung, Elizabeth; Osher, Jonas; Huppa, Chrisopher

2017-05-01

Hemimandibular hyperplasia is characterized by an obvious overgrowth in the size of the mandible on one side, which can extend up to the midline causing facial asymmetry. Surgical resection of the overgrowth depends heavily on the skill and experience of the surgeon. This report describes a novel methodology of applying three-dimensional computer-aided-design and computer-aided-manufacturing principles in improving the outcome of surgery in 2 mandibular hyperplasia patients. Both patients had their cone beam computer tomography (CBCT) scan performed. CMF Pro Plan software (v. 2.1) was used to process the scan data into virtual 3-dimensional models of the maxilla and mandible. Head tilt was adjusted manually by following horizontal reference. Facial asymmetry secondary to mandibular hypertrophy was obvious on frontal and lateral views. Simulation functions were followed including mirror imaging of the unaffected mandibular side into the hyperplastic side and position was optimized by translation and orientation functions. Reconstruction of virtual symmetry was assessed and checked by running 3-dimensional measurements. Then, subtraction functions were used to create a 3-dimensional template defining the outline of the lower mandibular osteotomy needed. Precision of mandibular teeth was enhanced by amalgamating the CBCT scan with e-cast scan of the patient lower teeth. 3-Matic software (v. 10.0) was used in designing cutting guide(s) that define the amount of overgrowth to be resected. The top section of the guide was resting on the teeth hence ensuring stability and accuracy while positioning it. The guide design was exported as an .stl file and printed using in-house 3-dimensional printer in biocompatible resin. Three-dimensional technologies of both softwares (CMF Pro Plan and 3-Matic) are accurate and reliable methods in the diagnosis, treatment planning, and designing of cutting guides that optimize surgical correction of hemimandibular hyperplasia at timely and cost-effect manner.

Three-dimensional virtual planning in orthognathic surgery enhances the accuracy of soft tissue prediction.

PubMed

Van Hemelen, Geert; Van Genechten, Maarten; Renier, Lieven; Desmedt, Maria; Verbruggen, Elric; Nadjmi, Nasser

2015-07-01

Throughout the history of computing, shortening the gap between the physical and digital world behind the screen has always been strived for. Recent advances in three-dimensional (3D) virtual surgery programs have reduced this gap significantly. Although 3D assisted surgery is now widely available for orthognathic surgery, one might still argue whether a 3D virtual planning approach is a better alternative to a conventional two-dimensional (2D) planning technique. The purpose of this study was to compare the accuracy of a traditional 2D technique and a 3D computer-aided prediction method. A double blind randomised prospective study was performed to compare the prediction accuracy of a traditional 2D planning technique versus a 3D computer-aided planning approach. The accuracy of the hard and soft tissue profile predictions using both planning methods was investigated. There was a statistically significant difference between 2D and 3D soft tissue planning (p < 0.05). The statistically significant difference found between 2D and 3D planning and the actual soft tissue outcome was not confirmed by a statistically significant difference between methods. The 3D planning approach provides more accurate soft tissue planning. However, the 2D orthognathic planning is comparable to 3D planning when it comes to hard tissue planning. This study provides relevant results for choosing between 3D and 2D planning in clinical practice. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Three-dimensional ultrasound and image-directed surgery: implications for operating room personnel.

PubMed

Macedonia, C

1997-04-01

The proliferation of new imaging technologies is having a profound impact on all surgical specialties. New means of surgical visualization are allowing more surgeries to be performed less invasively. Three-dimensional ultrasound is a technology that has potential as a diagnostic tool, as a presurgical planning simulator, and as an adjunct to image-directed surgery. This article describes how three-dimensional ultrasound is being used by the United States Department of Defense and how it may change the role of the perioperative nurse in the near future.

Cardiac dimensional analysis by use of biplane cineradiography: description and validation of method.

PubMed

Lipscomb, K

1980-01-01

Biplane cineradiography is a potentially powerful tool for precise measurement of intracardiac dimensions. The most systematic approach to these measurements is the creation of a three-dimensional coordinate system within the x-ray field. Using this system, interpoint distances, such as between radiopaque clips or coronary artery bifurcations, can be calculated by use of the Pythagoras theorem. Alternatively, calibration factors can be calculated in order to determine the absolute dimensions of a structure, such as a ventricle or coronary artery. However, cineradiography has two problems that have precluded widespread use of the system. These problems are pincushion distortion and variable image magnification. In this paper, methodology to quantitate and compensate for these variables is presented. The method uses radiopaque beads permanently mounted in the x-ray field. The position of the bead images on the x-ray film determine the compensation factors. Using this system, measurements are made with a standard deviation of approximately 1% of the true value.

Advancing three-dimensional MEMS by complimentary laser micro manufacturing

NASA Astrophysics Data System (ADS)

Palmer, Jeremy A.; Williams, John D.; Lemp, Tom; Lehecka, Tom M.; Medina, Francisco; Wicker, Ryan B.

2006-01-01

This paper describes improvements that enable engineers to create three-dimensional MEMS in a variety of materials. It also provides a means for selectively adding three-dimensional, high aspect ratio features to pre-existing PMMA micro molds for subsequent LIGA processing. This complimentary method involves in situ construction of three-dimensional micro molds in a stand-alone configuration or directly adjacent to features formed by x-ray lithography. Three-dimensional micro molds are created by micro stereolithography (MSL), an additive rapid prototyping technology. Alternatively, three-dimensional features may be added by direct femtosecond laser micro machining. Parameters for optimal femtosecond laser micro machining of PMMA at 800 nanometers are presented. The technical discussion also includes strategies for enhancements in the context of material selection and post-process surface finish. This approach may lead to practical, cost-effective 3-D MEMS with the surface finish and throughput advantages of x-ray lithography. Accurate three-dimensional metal microstructures are demonstrated. Challenges remain in process planning for micro stereolithography and development of buried features following femtosecond laser micro machining.

Influence of Objective Three-Dimensional Measures and Movement Images on Surgeon Treatment Planning for Lip Revision Surgery

PubMed Central

Trotman, Carroll-Ann; Phillips, Ceib; Faraway, Julian J.; Hartman, Terry; van Aalst, John A.

2013-01-01

Objective To determine whether a systematic evaluation of facial soft tissues of patients with cleft lip and palate, using facial video images and objective three-dimensional measurements of movement, change surgeons’ treatment plans for lip revision surgery. Design Prospective longitudinal study. Setting The University of North Carolina School of Dentistry. Patients, Participants A group of patients with repaired cleft lip and palate (n = 21), a noncleft control group (n = 37), and surgeons experienced in cleft care. Interventions Lip revision. Main Outcome Measures (1) facial photographic images; (2) facial video images during animations; (3) objective three-dimensional measurements of upper lip movement based on z scores; and (4) objective dynamic and visual three-dimensional measurement of facial soft tissue movement. Results With the use of the video images plus objective three-dimensional measures, changes were made to the problem list of the surgical treatment plan for 86% of the patients (95% confidence interval, 0.64 to 0.97) and the surgical goals for 71% of the patients (95% confidence interval, 0.48 to 0.89). The surgeon group varied in the percentage of patients for whom the problem list was modified, ranging from 24% (95% confidence interval, 8% to 47%) to 48% (95% confidence interval, 26% to 70%) of patients, and the percentage for whom the surgical goals were modified, ranging from 14% (94% confidence interval, 3% to 36%) to 48% (95% confidence interval, 26% to 70%) of patients. Conclusions For all surgeons, the additional assessment components of the systematic valuation resulted in a change in clinical decision making for some patients. PMID:23855676

Postoperative outcomes of two- and three-dimensional planning in orthognathic surgery: A comparative study.

PubMed

Wu, Ting-Yu; Lin, Hsiu-Hsia; Lo, Lun-Jou; Ho, Cheng-Ting

2017-08-01

Compared with conventional two-dimensional (2D) planning, three-dimensional (3D) planning in orthognathic surgery yields more accurate anatomical information and enables the precise positioning of maxillary and mandibular segments, particularly for patients with facial asymmetry. Accordingly, surgical outcomes achieved using 3D planning should be superior. This study determined the differences between the 2D and 3D planning techniques by comparing their surgical outcomes. In this retrospective study, patients who underwent surgery following the traditional 2D planning technique were classified into the 2D planning group. Patients in whom the 2D plan was transferred to a 3D system after surgical simulation were classified into the 3D planning group. Surgical outcomes were compared using cephalometric measurements and patient perception of the results. In the 3D planning group, more favorable results were observed in frontal symmetry, change in the angle between the orbital and occlusal lines, frontal ramus inclination, and the distances from the mandibular central incisor and menton to the midsagittal line. No significant differences were observed in the lateral profiles (SNA, SNB, ANB, and angle convexity) of the two groups. Patient satisfaction was favorable in the two groups, but more patients in the 3D planning group reported being very satisfied. The 3D planning technique provided superior overall outcomes. The study findings can be used to augment clinical planning and surgical execution when using a conventional approach. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

NAVSTAR GPS Simulation and Analysis Program (Interim Report)

DOT National Transportation Integrated Search

1983-10-01

This study assesses the capability of the planned NAVSTAR Global Positioning System (GPS) to meet civil navigation requirements. When it becomes operational in about 1983, NAVSTAR GPS will provide accurate two-dimensional and three-dimensional servic...

Real-time 3D transesophageal echocardiography-guided closure of a complicated patent ductus arteriosus in a dog.

PubMed

Doocy, K R; Nelson, D A; Saunders, A B

2017-06-01

Advanced imaging modalities are becoming more widely available in veterinary cardiology, including the use of transesophageal echocardiography (TEE) during occlusion of patent ductus arteriosus (PDA) in dogs. The dog in this report had a complex history of attempted ligation and a large PDA that initially precluded device placement thereby limiting the options for PDA closure. Following a second thoracotomy and partial ligation, the morphology of the PDA was altered and device occlusion was an option. Angiographic assessment of the PDA was limited by the presence of hemoclips, and the direction of ductal flow related to the change in anatomy following ligature placement. Intra-operative TEE, in particular real-time three-dimensional imaging, was pivotal for assessing the PDA morphology, monitoring during the procedure, selecting the device size, and confirming device placement. The TEE images increased operator confidence that the size and location of the device were appropriate before release despite the unusual position. This report highlights the benefit of intra-operative TEE, in particular real-time three-dimensional imaging, for successful PDA occlusion in a complicated case. Copyright © 2017 Elsevier B.V. All rights reserved.

PARTIAL RESTRAINING FORCE INTRODUCTION METHOD FOR DESIGNING CONSTRUCTION COUNTERMESURE ON ΔB METHOD

NASA Astrophysics Data System (ADS)

Nishiyama, Taku; Imanishi, Hajime; Chiba, Noriyuki; Ito, Takao

Landslide or slope failure is a three-dimensional movement phenomenon, thus a three-dimensional treatment makes it easier to understand stability. The ΔB method (simplified three-dimensional slope stability analysis method) is based on the limit equilibrium method and equals to an approximate three-dimensional slope stability analysis that extends two-dimensional cross-section stability analysis results to assess stability. This analysis can be conducted using conventional spreadsheets or two-dimensional slope stability computational software. This paper describes the concept of the partial restraining force in-troduction method for designing construction countermeasures using the distribution of the restraining force found along survey lines, which is based on the distribution of survey line safety factors derived from the above-stated analysis. This paper also presents the transverse distributive method of restraining force used for planning ground stabilizing on the basis of the example analysis.

Application of Magnetic Resonance Imaging and Three-Dimensional Treatment Planning in the Treatment of Orbital Lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudoltz, Marc S.; Ayyangar, Komanduri; Mohiuddin, Mohammed

Radiotherapy for lymphoma of the orbit must be individualized for each patient and clinical setting. Most techniques focus on optimizing the dose to the tumor while sparing the lens. This study describes a technique utilizing magnetic resonance imaging (MRI) and three dimensional (3D) planning in the treatment of orbital lymphoma. A patient presented with an intermediate grade lymphoma of the right orbit. The prescribed tumor dose was 4050 cGy in 18 fractions. Three D planning was carried out and tumor volumes, retina, and lens were subsequently outlined. Dose calculations including dose volume histograms of the target, retina, and lens weremore » then performed. Part of the retina was outside of the treatment volume while 50% of the retina received 90% or more of the prescribed dose. The patient was clinically NED when last seen 2 years following therapy with no treatment-related morbidity. Patients with lymphomas of the orbit can be optimally treated using MRI based 3D treatment planning.« less

Improved Virtual Planning for Bimaxillary Orthognathic Surgery.

PubMed

Hatamleh, Muhanad; Turner, Catherine; Bhamrah, Gurprit; Mack, Gavin; Osher, Jonas

2016-09-01

Conventional model surgery planning for bimaxillary orthognathic surgery can be laborious, time-consuming and may contain potential errors; hence three-dimensional (3D) virtual orthognathic planning has been proven to be an efficient, reliable, and cost-effective alternative. In this report, the 3D planning is described for a patient presenting with a Class III incisor relationship on a Skeletal III base with pan facial asymmetry complicated by reverse overjet and anterior open bite. A combined scan data of direct cone beam computer tomography and indirect dental scan were used in the planning. Additionally, a new method of establishing optimum intercuspation by scanning dental casts in final occlusion and positioning it to the composite-scans model was shown. Furthermore, conventional model surgery planning was carried out following in-house protocol. Intermediate and final intermaxillary splints were produced following the conventional method and 3D printing. Three-dimensional planning showed great accuracy and treatment outcome and reduced laboratory time in comparison with the conventional method. Establishing the final dental occlusion on casts and integrating it in final 3D planning enabled us to achieve the best possible intercuspation.

Three-Dimensional Printing Surgical Applications.

PubMed

AlAli, Ahmad B; Griffin, Michelle F; Butler, Peter E

2015-01-01

Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice.

The impact of the fabrication method on the three-dimensional accuracy of an implant surgery template.

PubMed

Matta, Ragai-Edward; Bergauer, Bastian; Adler, Werner; Wichmann, Manfred; Nickenig, Hans-Joachim

2017-06-01

The use of a surgical template is a well-established method in advanced implantology. In addition to conventional fabrication, computer-aided design and computer-aided manufacturing (CAD/CAM) work-flow provides an opportunity to engineer implant drilling templates via a three-dimensional printer. In order to transfer the virtual planning to the oral situation, a highly accurate surgical guide is needed. The aim of this study was to evaluate the impact of the fabrication method on the three-dimensional accuracy. The same virtual planning based on a scanned plaster model was used to fabricate a conventional thermo-formed and a three-dimensional printed surgical guide for each of 13 patients (single tooth implants). Both templates were acquired individually on the respective plaster model using an optical industrial white-light scanner (ATOS II, GOM mbh, Braunschweig, Germany), and the virtual datasets were superimposed. Using the three-dimensional geometry of the implant sleeve, the deviation between both surgical guides was evaluated. The mean discrepancy of the angle was 3.479° (standard deviation, 1.904°) based on data from 13 patients. Concerning the three-dimensional position of the implant sleeve, the highest deviation was in the Z-axis at 0.594 mm. The mean deviation of the Euclidian distance, dxyz, was 0.864 mm. Although the two different fabrication methods delivered statistically significantly different templates, the deviations ranged within a decimillimeter span. Both methods are appropriate for clinical use. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

SU-C-BRD-07: Three-Dimensional Dose Reconstruction in the Presence of Inhomogeneities Using Fast EPID-Based Back-Projection Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Q; Cao, R; Pei, X

2015-06-15

Purpose: Three-dimensional dose verification can detect errors introduced by the treatment planning system (TPS) or differences between planned and delivered dose distribution during the treatment. The aim of the study is to extend a previous in-house developed three-dimensional dose reconstructed model in homogeneous phantom to situtions in which tissue inhomogeneities are present. Methods: The method was based on the portal grey images from an electronic portal imaging device (EPID) and the relationship between beamlets and grey-scoring voxels at the position of the EPID. The relationship was expressed in the form of grey response matrix that was quantified using thickness-dependence scattermore » kernels determined by series of experiments. From the portal grey-value distribution information measured by the EPID the two-dimensional incident fluence distribution was reconstructed based on the grey response matrix using a fast iterative algorithm. The accuracy of this approach was verified using a four-field intensity-modulated radiotherapy (IMRT) plan for the treatment of lung cancer in anthopomorphic phantom. Each field had between twenty and twenty-eight segments and was evaluated by comparing the reconstructed dose distribution with the measured dose. Results: The gamma-evaluation method was used with various evaluation criteria of dose difference and distance-to-agreement: 3%/3mm and 2%/2 mm. The dose comparison for all irradiated fields showed a pass rate of 100% with the criterion of 3%/3mm, and a pass rate of higher than 92% with the criterion of 2%/2mm. Conclusion: Our experimental results demonstrate that our method is capable of accurately reconstructing three-dimensional dose distribution in the presence of inhomogeneities. Using the method, the combined planning and treatment delivery process is verified, offing an easy-to-use tool for the verification of complex treatments.« less

Dosimetric aspects of breast radiotherapy with three-dimensional and intensity-modulated radiotherapy helical tomotherapy planning modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, Poonam; Service of Radiation Therapy, University of Wisconsin Aspirus Cancer Center, Wisconsin Rapids, WI; Yan, Yue, E-mail: yyan5@mdanderson.org

In this work, we investigated the dosimetric differences between the intensity-modulated radiotherapy (IMRT) plans and the three-dimensional (3D) helical plans based on the TomoTherapy system. A total of 15 patients with supine setup were randomly selected from the data base. For patients with lumpectomy planning target volume (PTV), regional lymph nodes were also included as part of the target. For dose sparing, the significant differences between the helical IMRT and helical 3D were only found in the heart and contralateral breast. For the dose to the heart, helical IMRT reduced the maximum point dose by 6.98 Gy compared to themore » helical 3D plan (p = 0.01). For contralateral breast, the helical IMRT plans significantly reduced the maximum point dose by 5.6 Gy compared to the helical 3D plan. However, compared to the helical 3D plan, the helical IMRT plan increased the volume for lower dose (13.08% increase in V{sub 5} {sub Gy}, p = 0.01). In general, there are no significant differences in dose sparing between helical IMRT and helical 3D plans.« less

Automatic repositioning of jaw segments for three-dimensional virtual treatment planning of orthognathic surgery.

PubMed

Santos, Rodrigo Mologni Gonçalves Dos; De Martino, José Mario; Passeri, Luis Augusto; Attux, Romis Ribeiro de Faissol; Haiter Neto, Francisco

2017-09-01

To develop a computer-based method for automating the repositioning of jaw segments in the skull during three-dimensional virtual treatment planning of orthognathic surgery. The method speeds up the planning phase of the orthognathic procedure, releasing surgeons from laborious and time-consuming tasks. The method finds the optimal positions for the maxilla, mandibular body, and bony chin in the skull. Minimization of cephalometric differences between measured and standard values is considered. Cone-beam computed tomographic images acquired from four preoperative patients with skeletal malocclusion were used for evaluating the method. Dentofacial problems of the four patients were rectified, including skeletal malocclusion, facial asymmetry, and jaw discrepancies. The results show that the method is potentially able to be used in routine clinical practice as support for treatment-planning decisions in orthognathic surgery. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

The accuracy of two-dimensional planning for routine orthognathic surgery.

PubMed

Rustemeyer, Jan; Groddeck, Alexander; Zwerger, Stefan; Bremerich, Andreas

2010-06-01

Two-dimensional cephalometric planning software should be helpful for prediction of hard tissue outcome after bilateral sagittal split ramus osteotomy (BSSRO) or bimaxillary osteotomy, but transferring two-dimensional data to three-dimensions (including mock operation and surgery) may result in errors. The objective of this retrospective study was to analyze deviations between predicted results and postoperative outcome using cephalometric analyses, and to evaluate this procedure for daily use. Fifty-four subjects (mean (SD) age 26 (8) years) had a BSSRO (n=21) alone or in combination with Le Fort I osteotomy (n=33). Predictions were made for each case by cephalometric planning software and mock operations done with study models. Postoperative cephalograms were obtained after 14 days and compared with predicted cephalograms for sagittal (SNA, SNB, ANB,) and vertical (ArMeGo, ML-NSL, NL-NSL) measurements. Mean (SD) differences for all measurements varied between 1.3 degrees (1.1 degrees) and 2.2 degrees (1.6 degrees) for BSSRO; and between 1.1 degrees (1.3 degrees) and 2.2 degrees (1.6 degrees) for bimaxillary osteotomy. There were no significant differences between measurements or operations, indicating that the predictions were accurate. A difference of up to 8.5 degrees could be measured in a single case. Cephalometric prediction therefore remains an accurate tool for planning, particularly maxillary rearrangement in the vertical and sagittal dimension for routine operations. If greater shifts in the transversal dimension are necessary, exact planning should be adapted with three-dimensional planning devices to avoid significant differences. Copyright 2009 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Ray-tracing in three dimensions for calculation of radiation-dose calculations. Master's thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, D.R.

1986-05-27

This thesis addresses several methods of calculating the radiation-dose distribution for use by technicians or clinicians in radiation-therapy treatment planning. It specifically covers the calculation of the effective pathlength of the radiation beam for use in beam models representing the dose distribution. A two-dimensional method by Bentley and Milan is compared to the method of Strip Trees developed by Duda and Hart and then a three-dimensional algorithm built to perform the calculations in three dimensions. The use of PRISMS conforms easily to the obtained CT Scans and provides a means of only doing two-dimensional ray-tracing while performing three-dimensional dose calculations.more » This method is already being applied and used in actual calculations.« less

[Application of three-dimensional digital technology in the diagnosis and treatment planning in orthodontics].

PubMed

Bai, Y X

2016-06-01

Three-dimensional(3D)digital technology has been widely used in the field of orthodontics in clinical examination, diagnosis, treatment and curative effect evaluation. 3D digital technology greatly improves the accuracy of diagnosis and treatment, and provides effective means for personalized orthodontic treatment. This review focuses on the application of 3D digital technology in the field of orthodontics.

Three-Dimensional Printing Surgical Applications

PubMed Central

Griffin, Michelle F.; Butler, Peter E.

2015-01-01

Introduction: Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. Objective: To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Methods: Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Discussion: Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Conclusion: Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice. PMID:26301002

Expanding the limits of endoscopic intraorbital tumor resection using 3-dimensional reconstruction.

PubMed

Gregorio, Luciano Lobato; Busaba, Nicolas Y; Miyake, Marcel M; Freitag, Suzanne K; Bleier, Benjamin S

2017-12-26

Endoscopic orbital surgery is a nascent field and new tools are required to assist with surgical planning and to ascertain the limits of the tumor resectability. We purpose to utilize three-dimensional radiographic reconstruction to define the theoretical lateral limit of endoscopic resectability of primary orbital tumors and to apply these boundary conditions to surgical cases. A three-dimensional orbital model was rendered in 4 representative patients presenting with primary orbital tumors using OsiriX open source imaging software. A 2-Dimensional plane was propagated between the contralateral nare and a line tangential to the long axis of the optic nerve reflecting the trajectory of a trans-septal approach. Any tumor volume falling medial to the optic nerve and/or within the space inferior to this plane of resectability was considered theoretically resectable regardless of how far it extended lateral to the optic nerve as nerve retraction would be unnecessary. Actual tumor volumes were then superimposed over this plan and correlated with surgical outcomes. Among the 4 lesions analyzed, two were fully medial to the optic nerve, one extended lateral to the optic nerve but remained inferior to the plane of resectability, and one extended both lateral to the optic nerve and superior to the plane of resectability. As predicted by the three-dimensional modeling, a complete resection was achieved in all lesions except one that transgressed the plane of resectability. No new diplopia or vision loss was observed in any patient. Three-dimensional reconstruction enhances preoperative planning for endoscopic orbital surgery. Tumors that extend lateral to the optic nerve may still be candidates for a purely endoscopic resection as long as they do not extend above the plane of resectability described herein. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Pursuing Mirror Image Reconstruction in Unilateral Microtia: Customizing Auricular Framework by Application of Three-Dimensional Imaging and Three-Dimensional Printing.

PubMed

Chen, Hsin-Yu; Ng, Li-Shia; Chang, Chun-Shin; Lu, Ting-Chen; Chen, Ning-Hung; Chen, Zung-Chung

2017-06-01

Advances in three-dimensional imaging and three-dimensional printing technology have expanded the frontier of presurgical design for microtia reconstruction from two-dimensional curved lines to three-dimensional perspectives. This study presents an algorithm for combining three-dimensional surface imaging, computer-assisted design, and three-dimensional printing to create patient-specific auricular frameworks in unilateral microtia reconstruction. Between January of 2015 and January of 2016, six patients with unilateral microtia were enrolled. The average age of the patients was 7.6 years. A three-dimensional image of the patient's head was captured by 3dMDcranial, and virtual sculpture carried out using Geomagic Freeform software and a Touch X Haptic device for fabrication of the auricular template. Each template was tailored according to the patient's unique auricular morphology. The final construct was mirrored onto the defective side and printed out with biocompatible acrylic material. During the surgery, the prefabricated customized template served as a three-dimensional guide for surgical simulation and sculpture of the MEDPOR framework. Average follow-up was 10.3 months. Symmetric and good aesthetic results with regard to auricular shape, projection, and orientation were obtained. One case with severe implant exposure was salvaged with free temporoparietal fascia transfer and skin grafting. The combination of three-dimensional imaging and manufacturing technology with the malleability of MEDPOR has surpassed existing limitations resulting from the use of autologous materials and the ambiguity of two-dimensional planning. This approach allows surgeons to customize the auricular framework in a highly precise and sophisticated manner, taking a big step closer to the goal of mirror-image reconstruction for unilateral microtia patients. Therapeutic, IV.

Design of an advanced flight planning system

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Goka, T.

1985-01-01

The demand for both fuel conservation and four-dimensional traffic management require that the preflight planning process be designed to account for advances in airborne flight management and weather forecasting. The steps and issues in designing such an advanced flight planning system are presented. Focus is placed on the different optimization options for generating the three-dimensional reference path. For the cruise phase, one can use predefined jet routes, direct routes based on a network of evenly spaced grid points, or a network where the grid points are existing navaid locations. Each choice has its own problem in determining an optimum solution. Finding the reference path is further complicated by choice of cruise altitude levels, use of a time-varying weather field, and requiring a fixed time-of-arrival (four-dimensional problem).

Computer-Assisted Orthognathic Surgery for Patients with Cleft Lip/Palate: From Traditional Planning to Three-Dimensional Surgical Simulation

PubMed Central

Lonic, Daniel; Pai, Betty Chien-Jung; Yamaguchi, Kazuaki; Chortrakarnkij, Peerasak; Lin, Hsiu-Hsia; Lo, Lun-Jou

2016-01-01

Background Although conventional two-dimensional (2D) methods for orthognathic surgery planning are still popular, the use of three-dimensional (3D) simulation is steadily increasing. In facial asymmetry cases such as in cleft lip/palate patients, the additional information can dramatically improve planning accuracy and outcome. The purpose of this study is to investigate which parameters are changed most frequently in transferring a traditional 2D plan to 3D simulation, and what planning parameters can be better adjusted by this method. Patients and Methods This prospective study enrolled 30 consecutive patients with cleft lip and/or cleft palate (mean age 18.6±2.9 years, range 15 to 32 years). All patients received two-jaw single-splint orthognathic surgery. 2D orthodontic surgery plans were transferred into a 3D setting. Severe bony collisions in the ramus area after 2D plan transfer were noted. The position of the maxillo-mandibular complex was evaluated and eventually adjusted. Position changes of roll, midline, pitch, yaw, genioplasty and their frequency within the patient group were recorded as an alternation of the initial 2D plan. Patients were divided in groups of no change from the original 2D plan and changes in one, two, three and four of the aforementioned parameters as well as subgroups of unilateral, bilateral cleft lip/palate and isolated cleft palate cases. Postoperative OQLQ scores were obtained for 20 patients who finished orthodontic treatment. Results 83.3% of 2D plans were modified, mostly concerning yaw (63.3%) and midline (36.7%) adjustments. Yaw adjustments had the highest mean values in total and in all subgroups. Severe bony collisions as a result of 2D planning were seen in 46.7% of patients. Possible asymmetry was regularly foreseen and corrected in the 3D simulation. Conclusion Based on our findings, 3D simulation renders important information for accurate planning in complex cleft lip/palate cases involving facial asymmetry that is regularly missed in conventional 2D planning. PMID:27002726

Computer-Assisted Orthognathic Surgery for Patients with Cleft Lip/Palate: From Traditional Planning to Three-Dimensional Surgical Simulation.

PubMed

Lonic, Daniel; Pai, Betty Chien-Jung; Yamaguchi, Kazuaki; Chortrakarnkij, Peerasak; Lin, Hsiu-Hsia; Lo, Lun-Jou

2016-01-01

Although conventional two-dimensional (2D) methods for orthognathic surgery planning are still popular, the use of three-dimensional (3D) simulation is steadily increasing. In facial asymmetry cases such as in cleft lip/palate patients, the additional information can dramatically improve planning accuracy and outcome. The purpose of this study is to investigate which parameters are changed most frequently in transferring a traditional 2D plan to 3D simulation, and what planning parameters can be better adjusted by this method. This prospective study enrolled 30 consecutive patients with cleft lip and/or cleft palate (mean age 18.6±2.9 years, range 15 to 32 years). All patients received two-jaw single-splint orthognathic surgery. 2D orthodontic surgery plans were transferred into a 3D setting. Severe bony collisions in the ramus area after 2D plan transfer were noted. The position of the maxillo-mandibular complex was evaluated and eventually adjusted. Position changes of roll, midline, pitch, yaw, genioplasty and their frequency within the patient group were recorded as an alternation of the initial 2D plan. Patients were divided in groups of no change from the original 2D plan and changes in one, two, three and four of the aforementioned parameters as well as subgroups of unilateral, bilateral cleft lip/palate and isolated cleft palate cases. Postoperative OQLQ scores were obtained for 20 patients who finished orthodontic treatment. 83.3% of 2D plans were modified, mostly concerning yaw (63.3%) and midline (36.7%) adjustments. Yaw adjustments had the highest mean values in total and in all subgroups. Severe bony collisions as a result of 2D planning were seen in 46.7% of patients. Possible asymmetry was regularly foreseen and corrected in the 3D simulation. Based on our findings, 3D simulation renders important information for accurate planning in complex cleft lip/palate cases involving facial asymmetry that is regularly missed in conventional 2D planning.

3D-nanostructured Au electrodes for the event-specific detection of MON810 transgenic maize.

PubMed

Fátima Barroso, M; Freitas, Maria; Oliveira, M Beatriz P P; de-Los-Santos-Álvarez, Noemí; Lobo-Castañón, María Jesús; Delerue-Matos, Cristina

2015-03-01

In the present work, the development of a genosensor for the event-specific detection of MON810 transgenic maize is proposed. Taking advantage of nanostructuration, a cost-effective three dimensional electrode was fabricated and a ternary monolayer containing a dithiol, a monothiol and the thiolated capture probe was optimized to minimize the unspecific signals. A sandwich format assay was selected as a way of precluding inefficient hybridization associated with stable secondary target structures. A comparison between the analytical performance of the Au nanostructured electrodes and commercially available screen-printed electrodes highlighted the superior performance of the nanostructured ones. Finally, the genosensor was effectively applied to detect the transgenic sequence in real samples, showing its potential for future quantitative analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel bio-mimicking, planar nano-edge microelectrode enables enhanced long-term neural recording

NASA Astrophysics Data System (ADS)

Wijdenes, Pierre; Ali, Hasan; Armstrong, Ryden; Zaidi, Wali; Dalton, Colin; Syed, Naweed I.

2016-10-01

Our inability to accurately monitor individual neurons and their synaptic activity precludes fundamental understanding of brain function under normal and various pathological conditions. However, recent breakthroughs in micro- and nano-scale fabrication processes have advanced the development of neuro-electronic hybrid technology. Among such devices are three-dimensional and planar electrodes, offering the advantages of either high fidelity or longer-term recordings respectively. Here, we present the next generation of planar microelectrode arrays with “nano-edges” that enable long-term (≥1 month) and high fidelity recordings at a resolution 15 times higher than traditional planar electrodes. This novel technology enables better understanding of brain function and offers a tremendous opportunity towards the development of future bionic hybrids and drug discovery devices.

Numerical Viscosity and the Survival of Gas Giant Protoplanets in Disk Simulations

NASA Astrophysics Data System (ADS)

Pickett, Megan K.; Durisen, Richard H.

2007-01-01

We present three-dimensional hydrodynamic simulations of a gravitationally unstable protoplanetary disk model under the condition of local isothermality. Ordinarily, local isothermality precludes the need for an artificial viscosity (AV) scheme to mediate shocks. Without AV, the disk evolves violently, shredding into dense (although short-lived) clumps. When we introduce our AV treatment in the momentum equation, but without heating due to irreversible compression, our grid-based simulations begin to resemble smoothed particle hydrodynamics (SPH) calculations, where clumps are more likely to survive many orbits. In fact, the standard SPH viscosity appears comparable in strength to the AV that leads to clump longevity in our code. This sensitivity to one numerical parameter suggests extreme caution in interpreting simulations by any code in which long-lived gaseous protoplanetary bodies appear.

Enantioselective synthesis of pactamycin, a complex antitumor antibiotic.

PubMed

Malinowski, Justin T; Sharpe, Robert J; Johnson, Jeffrey S

2013-04-12

Medicinal application of many complex natural products is precluded by the impracticality of their chemical synthesis. Pactamycin, the most structurally intricate aminocyclopentitol antibiotic, displays potent antiproliferative properties across multiple phylogenetic domains, but it is highly cytotoxic. A limited number of analogs produced by genetic engineering technologies show reduced cytotoxicity against mammalian cells, renewing promise for therapeutic applications. For decades, an efficient synthesis of pactamycin amenable to analog derivatizations has eluded researchers. Here, we present a short asymmetric total synthesis of pactamycin. An enantioselective Mannich reaction and symmetry-breaking reduction sequence was designed to enable assembly of the entire carbon core skeleton in under five steps and control critical three-dimensional (stereochemical) functional group relationships. This modular route totals 15 steps and is immediately amenable for structural analog synthesis.

Comparison of three-dimensional vs. conventional radiotherapy in saving optic tract in paranasal sinus tumors.

PubMed

Kamian, S; Kazemian, A; Esfahani, M; Mohammadi, E; Aghili, M

2010-01-01

To assess the possibility of delivering a homogeneous irradiation with respect to maximal tolerated dose to the optic pathway for paranasal sinus (PNS) tumors. Treatment planning with conformal three-dimensional (3D) and conventional two-dimensional (2D) was done on CT scans of 20 patients who had early or advanced PNS tumors. Four cases had been previously irradiated. Dose-volume histograms (DVH) for the planning target volume (PTV) and the visual pathway including globes, chiasma and optic nerves were compared between the 2 treatment plannings. The area under curve (AUC) in the DVH of the globes on the same side and contralateral side of tumor involvement was significantly higher in 2D planning (p <0.05), which caused higher integral dose to both globes. Also, the AUC in the DVH of chiasma was higher in 2D treatment planning (p=0.002). The integral dose to the contralateral optic nerve was significantly lower with 3D planning (p=0.007), but there was no significant difference for the optic nerve which was on the same side of tumor involvement (p >0.05). The AUC in the DVH of PTV was not significant (201.1 + or - 16.23 mm(3) in 2D planning vs. 201.15 + or - 15.09 mm(3) in 3D planning). The volume of PTV which received 90% of the prescribed dose was 96.9 + or - 4.41 cm(3) in 2D planning and 97.2 + or - 2.61 cm(3) in 3D planning (p >0.05). 3D conformal radiotherapy (RT) for PNS tumors enables the delivery of radiation to the tumor with respect to critical organs with a lower toxicity to the optic pathway.

A Medipix quantum area detector allows rotation electron diffraction data collection from submicrometre three-dimensional protein crystals

PubMed Central

Nederlof, Igor; van Genderen, Eric; Li, Yao-Wang; Abrahams, Jan Pieter

2013-01-01

When protein crystals are submicrometre-sized, X-ray radiation damage precludes conventional diffraction data collection. For crystals that are of the order of 100 nm in size, at best only single-shot diffraction patterns can be collected and rotation data collection has not been possible, irrespective of the diffraction technique used. Here, it is shown that at a very low electron dose (at most 0.1 e− Å−2), a Medipix2 quantum area detector is sufficiently sensitive to allow the collection of a 30-frame rotation series of 200 keV electron-diffraction data from a single ∼100 nm thick protein crystal. A highly parallel 200 keV electron beam (λ = 0.025 Å) allowed observation of the curvature of the Ewald sphere at low resolution, indicating a combined mosaic spread/beam divergence of at most 0.4°. This result shows that volumes of crystal with low mosaicity can be pinpointed in electron diffraction. It is also shown that strategies and data-analysis software (MOSFLM and SCALA) from X-ray protein crystallography can be used in principle for analysing electron-diffraction data from three-dimensional nanocrystals of proteins. PMID:23793148

Metamorphosis revealed: time-lapse three-dimensional imaging inside a living chrysalis.

PubMed

Lowe, Tristan; Garwood, Russell J; Simonsen, Thomas J; Bradley, Robert S; Withers, Philip J

2013-07-06

Studies of model insects have greatly increased our understanding of animal development. Yet, they are limited in scope to this small pool of model species: a small number of representatives for a hyperdiverse group with highly varied developmental processes. One factor behind this narrow scope is the challenging nature of traditional methods of study, such as histology and dissection, which can preclude quantitative analysis and do not allow the development of a single individual to be followed. Here, we use high-resolution X-ray computed tomography (CT) to overcome these issues, and three-dimensionally image numerous lepidopteran pupae throughout their development. The resulting models are presented in the electronic supplementary material, as are figures and videos, documenting a single individual throughout development. They provide new insight and details of lepidopteran metamorphosis, and allow the measurement of tracheal and gut volume. Furthermore, this study demonstrates early and rapid development of the tracheae, which become visible in scans just 12 h after pupation. This suggests that there is less remodelling of the tracheal system than previously expected, and is methodologically important because the tracheal system is an often-understudied character system in development. In the future, this form of time-lapse CT-scanning could allow faster and more detailed developmental studies on a wider range of taxa than is presently possible.

Integration of oncologic margins in three-dimensional virtual planning for head and neck surgery, including a validation of the software pathway.

PubMed

Kraeima, Joep; Schepers, Rutger H; van Ooijen, Peter M A; Steenbakkers, Roel J H M; Roodenburg, Jan L N; Witjes, Max J H

2015-10-01

Three-dimensional (3D) virtual planning of reconstructive surgery, after resection, is a frequently used method for improving accuracy and predictability. However, when applied to malignant cases, the planning of the oncologic resection margins is difficult due to visualisation of tumours in the current 3D planning. Embedding tumour delineation on a magnetic resonance image, similar to the routinely performed radiotherapeutic contouring of tumours, is expected to provide better margin planning. A new software pathway was developed for embedding tumour delineation on magnetic resonance imaging (MRI) within the 3D virtual surgical planning. The software pathway was validated by the use of five bovine cadavers implanted with phantom tumour objects. MRI and computed tomography (CT) images were fused and the tumour was delineated using radiation oncology software. This data was converted to the 3D virtual planning software by means of a conversion algorithm. Tumour volumes and localization were determined in both software stages for comparison analysis. The approach was applied to three clinical cases. A conversion algorithm was developed to translate the tumour delineation data to the 3D virtual plan environment. The average difference in volume of the tumours was 1.7%. This study reports a validated software pathway, providing multi-modality image fusion for 3D virtual surgical planning. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Accuracy of Three-Dimensional Planning in Surgery-First Orthognathic Surgery: Planning Versus Outcome.

PubMed

Tran, Ngoc Hieu; Tantidhnazet, Syrina; Raocharernporn, Somchart; Kiattavornchareon, Sirichai; Pairuchvej, Verasak; Wongsirichat, Natthamet

2018-05-01

The benefit of computer-assisted planning in orthognathic surgery (OGS) has been extensively documented over the last decade. This study aimed to evaluate the accuracy of three-dimensional (3D) virtual planning in surgery-first OGS. Fifteen patients with skeletal class III malocclusion who underwent bimaxillary OGS with surgery-first approach were included. A composite skull model was reconstructed using data from cone-beam computed tomography and stereolithography from a scanned dental cast. Surgical procedures were simulated using Simplant O&O software, and the virtual plan was transferred to the operation room using 3D-printed splints. Differences of the 3D measurements between the virtual plan and postoperative results were evaluated, and the accuracy was reported using root mean square deviation (RMSD) and the Bland-Altman method. The virtual planning was successfully transferred to surgery. The overall mean linear difference was 0.88 mm (0.79 mm for the maxilla and 1 mm for the mandible), and the overall mean angular difference was 1.16°. The RMSD ranged from 0.86 to 1.46 mm and 1.27° to 1.45°, within the acceptable clinical criteria. In this study, virtual surgical planning and 3D-printed surgical splints facilitated the diagnosis and treatment planning, and offered an accurate outcome in surgery-first OGS.

Three-dimensional printing of orbital and peri-orbital masses in three dogs and its potential applications in veterinary ophthalmology.

PubMed

Dorbandt, Daniel M; Joslyn, Stephen K; Hamor, Ralph E

2017-01-01

To describe the technique and utility of three-dimensional (3D) printing for orbital and peri-orbital masses and discuss other potential applications for 3D printing. Three dogs with a chronic history of nonpainful exophthalmos. Computed tomography (CT) and subsequent 3D printing of the head was performed on each case. CT confirmed a confined mass, and an ultrasound-guided biopsy was obtained in each circumstance. An orbitotomy was tentatively planned for each case, and a 3D print of each head with the associated globe and mass was created to assist in surgical planning. In case 1, the mass was located in the cranioventral aspect of the right orbit, and the histopathologic diagnosis was adenoma. In case 2, the mass was located within the lateral masseter muscle, ventral to the right orbit between the zygomatic arch and the ramus of the mandible. The histopathologic diagnosis in case 2 was consistent with a lipoma. In case 3, the mass was located in the ventral orbit, and the histopathologic diagnosis was histiocytic cellular infiltrate. Three-dimensional printing in cases with orbital and peri-orbital masses has exceptional potential for improved surgical planning and provides another modality for visualization to help veterinarians, students, and owners understand distribution of disease. Additionally, as the techniques of 3D printing continue to evolve, the potential exists to revolutionize ocular surgery and drug delivery. © 2016 American College of Veterinary Ophthalmologists.

Three-Dimensional Anatomic Evaluation of the Anterior Cruciate Ligament for Planning Reconstruction

PubMed Central

Hoshino, Yuichi; Kim, Donghwi; Fu, Freddie H.

2012-01-01

Anatomic study related to the anterior cruciate ligament (ACL) reconstruction surgery has been developed in accordance with the progress of imaging technology. Advances in imaging techniques, especially the move from two-dimensional (2D) to three-dimensional (3D) image analysis, substantially contribute to anatomic understanding and its application to advanced ACL reconstruction surgery. This paper introduces previous research about image analysis of the ACL anatomy and its application to ACL reconstruction surgery. Crucial bony landmarks for the accurate placement of the ACL graft can be identified by 3D imaging technique. Additionally, 3D-CT analysis of the ACL insertion site anatomy provides better and more consistent evaluation than conventional “clock-face” reference and roentgenologic quadrant method. Since the human anatomy has a complex three-dimensional structure, further anatomic research using three-dimensional imaging analysis and its clinical application by navigation system or other technologies is warranted for the improvement of the ACL reconstruction. PMID:22567310

[Extraction of buildings three-dimensional information from high-resolution satellite imagery based on Barista software].

PubMed

Zhang, Pei-feng; Hu, Yuan-man; He, Hong-shi

2010-05-01

The demand for accurate and up-to-date spatial information of urban buildings is becoming more and more important for urban planning, environmental protection, and other vocations. Today's commercial high-resolution satellite imagery offers the potential to extract the three-dimensional information of urban buildings. This paper extracted the three-dimensional information of urban buildings from QuickBird imagery, and validated the precision of the extraction based on Barista software. It was shown that the extraction of three-dimensional information of the buildings from high-resolution satellite imagery based on Barista software had the advantages of low professional level demand, powerful universality, simple operation, and high precision. One pixel level of point positioning and height determination accuracy could be achieved if the digital elevation model (DEM) and sensor orientation model had higher precision and the off-Nadir View Angle was relatively perfect.

Echocardiography Comparison Between Two and Three Dimensional Echocardiograms

NASA Technical Reports Server (NTRS)

2003-01-01

Echocardiography uses sound waves to image the heart and other organs. Developing a compact version of the latest technology improved the ease of monitoring crew member health, a critical task during long space flights. NASA researchers plan to adapt the three-dimensional (3-D) echocardiogram for space flight. The two-dimensional (2-D) echocardiogram utilized in orbit on the International Space Station (ISS) was effective, but difficult to use with precision. A heart image from a 2-D echocardiogram (left) is of a better quality than that from a 3-D device (right), but the 3-D imaging procedure is more user-friendly.

Customized "In-Office" Three-Dimensional Printing for Virtual Surgical Planning in Craniofacial Surgery.

PubMed

Mendez, Bernardino M; Chiodo, Michael V; Patel, Parit A

2015-07-01

Virtual surgical planning using three-dimensional (3D) printing technology has improved surgical efficiency and precision. A limitation to this technology is that production of 3D surgical models requires a third-party source, leading to increased costs (up to $4000) and prolonged assembly times (averaging 2-3 weeks). The purpose of this study is to evaluate the feasibility, cost, and production time of customized skull models created by an "in-office" 3D printer for craniofacial reconstruction. Two patients underwent craniofacial reconstruction with the assistance of "in-office" 3D printing technology. Three-dimensional skull models were created from a bioplastic filament with a 3D printer using computed tomography (CT) image data. The cost and production time for each model were measured. For both patients, a customized 3D surgical model was used preoperatively to plan split calvarial bone grafting and intraoperatively to more efficiently and precisely perform the craniofacial reconstruction. The average cost for surgical model production with the "in-office" 3D printer was $25 (cost of bioplastic materials used to create surgical model) and the average production time was 14  hours. Virtual surgical planning using "in office" 3D printing is feasible and allows for a more cost-effective and less time consuming method for creating surgical models and guides. By bringing 3D printing to the office setting, we hope to improve intraoperative efficiency, surgical precision, and overall cost for various types of craniofacial and reconstructive surgery.

Preoperative planning of thoracic surgery with use of three-dimensional reconstruction, rapid prototyping, simulation and virtual navigation.

PubMed

Heuts, Samuel; Sardari Nia, Peyman; Maessen, Jos G

2016-01-01

For the past decades, surgeries have become more complex, due to the increasing age of the patient population referred for thoracic surgery, more complex pathology and the emergence of minimally invasive thoracic surgery. Together with the early detection of thoracic disease as a result of innovations in diagnostic possibilities and the paradigm shift to personalized medicine, preoperative planning is becoming an indispensable and crucial aspect of surgery. Several new techniques facilitating this paradigm shift have emerged. Pre-operative marking and staining of lesions are already a widely accepted method of preoperative planning in thoracic surgery. However, three-dimensional (3D) image reconstructions, virtual simulation and rapid prototyping (RP) are still in development phase. These new techniques are expected to become an important part of the standard work-up of patients undergoing thoracic surgery in the future. This review aims at graphically presenting and summarizing these new diagnostic and therapeutic tools.

Virtual Surgical Planning in Craniofacial Surgery

PubMed Central

Chim, Harvey; Wetjen, Nicholas; Mardini, Samir

2014-01-01

The complex three-dimensional anatomy of the craniofacial skeleton creates a formidable challenge for surgical reconstruction. Advances in computer-aided design and computer-aided manufacturing technology have created increasing applications for virtual surgical planning in craniofacial surgery, such as preoperative planning, fabrication of cutting guides, and stereolithographic models and fabrication of custom implants. In this review, the authors describe current and evolving uses of virtual surgical planning in craniofacial surgery. PMID:25210509

Three-dimensional planning in craniomaxillofacial surgery

PubMed Central

Rubio-Palau, Josep; Prieto-Gundin, Alejandra; Cazalla, Asteria Albert; Serrano, Miguel Bejarano; Fructuoso, Gemma Garcia; Ferrandis, Francisco Parri; Baró, Alejandro Rivera

2016-01-01

Introduction: Three-dimensional (3D) planning in oral and maxillofacial surgery has become a standard in the planification of a variety of conditions such as dental implants and orthognathic surgery. By using custom-made cutting and positioning guides, the virtual surgery is exported to the operating room, increasing precision and improving results. Materials and Methods: We present our experience in the treatment of craniofacial deformities with 3D planning. Software to plan the different procedures has been selected for each case, depending on the procedure (Nobel Clinician, Kodak 3DS, Simplant O&O, Dolphin 3D, Timeus, Mimics and 3-Matic). The treatment protocol is exposed step by step from virtual planning, design, and printing of the cutting and positioning guides to patients’ outcomes. Conclusions: 3D planning reduces the surgical time and allows predicting possible difficulties and complications. On the other hand, it increases preoperative planning time and needs a learning curve. The only drawback is the cost of the procedure. At present, the additional preoperative work can be justified because of surgical time reduction and more predictable results. In the future, the cost and time investment will be reduced. 3D planning is here to stay. It is already a fact in craniofacial surgery and the investment is completely justified by the risk reduction and precise results. PMID:28299272

Three-dimensional planning in craniomaxillofacial surgery.

PubMed

Rubio-Palau, Josep; Prieto-Gundin, Alejandra; Cazalla, Asteria Albert; Serrano, Miguel Bejarano; Fructuoso, Gemma Garcia; Ferrandis, Francisco Parri; Baró, Alejandro Rivera

2016-01-01

Three-dimensional (3D) planning in oral and maxillofacial surgery has become a standard in the planification of a variety of conditions such as dental implants and orthognathic surgery. By using custom-made cutting and positioning guides, the virtual surgery is exported to the operating room, increasing precision and improving results. We present our experience in the treatment of craniofacial deformities with 3D planning. Software to plan the different procedures has been selected for each case, depending on the procedure (Nobel Clinician, Kodak 3DS, Simplant O&O, Dolphin 3D, Timeus, Mimics and 3-Matic). The treatment protocol is exposed step by step from virtual planning, design, and printing of the cutting and positioning guides to patients' outcomes. 3D planning reduces the surgical time and allows predicting possible difficulties and complications. On the other hand, it increases preoperative planning time and needs a learning curve. The only drawback is the cost of the procedure. At present, the additional preoperative work can be justified because of surgical time reduction and more predictable results. In the future, the cost and time investment will be reduced. 3D planning is here to stay. It is already a fact in craniofacial surgery and the investment is completely justified by the risk reduction and precise results.

Planning for the Introduction of the Metric System into Occupational Education Programs

ERIC Educational Resources Information Center

Low, A. W.

1974-01-01

A three-dimensional planning model for introducting the International System of Metric Units into Canadian occupational education curricula includes employment level, career area, and metric topics. A fourth dimension, time, is considered in four separate phases: familiarization, adoption, conversion, and compulsory usage.

Inverse planning in three-dimensional conformal and intensity-modulated radiotherapy of mid-thoracic oesophageal cancer.

PubMed

Wu, V W C; Sham, J S T; Kwong, D L W

2004-07-01

The aim of this study is to demonstrate the use of inverse planning in three-dimensional conformal radiation therapy (3DCRT) of oesophageal cancer patients and to evaluate its dosimetric results by comparing them with forward planning of 3DCRT and inverse planning of intensity-modulated radiotherapy (IMRT). For each of the 15 oesophageal cancer patients in this study, the forward 3DCRT, inverse 3DCRT and inverse IMRT plans were produced using the FOCUS treatment planning system. The dosimetric results and the planner's time associated with each of the treatment plans were recorded for comparison. The inverse 3DCRT plans showed similar dosimetric results to the forward plans in the planning target volume (PTV) and organs at risk (OARs). However, they were inferior to that of the IMRT plans in terms of tumour control probability and target dose conformity. Furthermore, the inverse 3DCRT plans were less effective in reducing the percentage lung volume receiving a dose below 25 Gy when compared with the IMRT plans. The inverse 3DCRT plans delivered a similar heart dose as in the forward plans, but higher dose than the IMRT plans. The inverse 3DCRT plans significantly reduced the operator's time by 2.5 fold relative to the forward plans. In conclusion, inverse planning for 3DCRT is a reasonable alternative to the forward planning for oesophageal cancer patients with reduction of the operator's time. However, IMRT has the better potential to allow further dose escalation and improvement of tumour control.

Three-Dimensional Liver Surgery Simulation: Computer-Assisted Surgical Planning with Three-Dimensional Simulation Software and Three-Dimensional Printing^.

PubMed

Oshiro, Yukio; Ohkohchi, Nobuhiro

2017-06-01

To perform accurate hepatectomy without injury, it is necessary to understand the anatomical relationship among the branches of Glisson's sheath, hepatic veins, and tumor. In Japan, three-dimensional (3D) preoperative simulation for liver surgery is becoming increasingly common, and liver 3D modeling and 3D hepatectomy simulation by 3D analysis software for liver surgery have been covered by universal healthcare insurance since 2012. Herein, we review the history of virtual hepatectomy using computer-assisted surgery (CAS) and our research to date, and we discuss the future prospects of CAS. We have used the SYNAPSE VINCENT medical imaging system (Fujifilm Medical, Tokyo, Japan) for 3D visualization and virtual resection of the liver since 2010. We developed a novel fusion imaging technique combining 3D computed tomography (CT) with magnetic resonance imaging (MRI). The fusion image enables us to easily visualize anatomic relationships among the hepatic arteries, portal veins, bile duct, and tumor in the hepatic hilum. In 2013, we developed an original software, called Liversim, which enables real-time deformation of the liver using physical simulation, and a randomized control trial has recently been conducted to evaluate the use of Liversim and SYNAPSE VINCENT for preoperative simulation and planning. Furthermore, we developed a novel hollow 3D-printed liver model whose surface is covered with frames. This model is useful for safe liver resection, has better visibility, and the production cost is reduced to one-third of a previous model. Preoperative simulation and navigation with CAS in liver resection are expected to help planning and conducting a surgery and surgical education. Thus, a novel CAS system will contribute to not only the performance of reliable hepatectomy but also to surgical education.

Entangled time in flocking: Multi-time-scale interaction reveals emergence of inherent noise

PubMed Central

Murakami, Hisashi

2018-01-01

Collective behaviors that seem highly ordered and result in collective alignment, such as schooling by fish and flocking by birds, arise from seamless shuffling (such as super-diffusion) and bustling inside groups (such as Lévy walks). However, such noisy behavior inside groups appears to preclude the collective behavior: intuitively, we expect that noisy behavior would lead to the group being destabilized and broken into small sub groups, and high alignment seems to preclude shuffling of neighbors. Although statistical modeling approaches with extrinsic noise, such as the maximum entropy approach, have provided some reasonable descriptions, they ignore the cognitive perspective of the individuals. In this paper, we try to explain how the group tendency, that is, high alignment, and highly noisy individual behavior can coexist in a single framework. The key aspect of our approach is multi-time-scale interaction emerging from the existence of an interaction radius that reflects short-term and long-term predictions. This multi-time-scale interaction is a natural extension of the attraction and alignment concept in many flocking models. When we apply this method in a two-dimensional model, various flocking behaviors, such as swarming, milling, and schooling, emerge. The approach also explains the appearance of super-diffusion, the Lévy walk in groups, and local equilibria. At the end of this paper, we discuss future developments, including extending our model to three dimensions. PMID:29689074

Applications of Three-Dimensional Printing in Surgery.

PubMed

Li, Chi; Cheung, Tsz Fung; Fan, Vei Chen; Sin, Kin Man; Wong, Chrisity Wai Yan; Leung, Gilberto Ka Kit

2017-02-01

Three-dimensional (3D) printing is a rapidly advancing technology in the field of surgery. This article reviews its contemporary applications in 3 aspects of surgery, namely, surgical planning, implants and prostheses, and education and training. Three-dimensional printing technology can contribute to surgical planning by depicting precise personalized anatomy and thus a potential improvement in surgical outcome. For implants and prosthesis, the technology might overcome the limitations of conventional methods such as visual discrepancy from the recipient's body and unmatching anatomy. In addition, 3D printing technology could be integrated into medical school curriculum, supplementing the conventional cadaver-based education and training in anatomy and surgery. Future potential applications of 3D printing in surgery, mainly in the areas of skin, nerve, and vascular graft preparation as well as ear reconstruction, are also discussed. Numerous trials and studies are still ongoing. However, scientists and clinicians are still encountering some limitations of the technology including high cost, long processing time, unsatisfactory mechanical properties, and suboptimal accuracy. These limitations might potentially hamper the applications of this technology in daily clinical practice.

Applications of 3D printing in the management of severe spinal conditions.

PubMed

Provaggi, Elena; Leong, Julian J H; Kalaskar, Deepak M

2017-06-01

The latest and fastest-growing innovation in the medical field has been the advent of three-dimensional printing technologies, which have recently seen applications in the production of low-cost, patient-specific medical implants. While a wide range of three-dimensional printing systems has been explored in manufacturing anatomical models and devices for the medical setting, their applications are cutting-edge in the field of spinal surgery. This review aims to provide a comprehensive overview and classification of the current applications of three-dimensional printing technologies in spine care. Although three-dimensional printing technology has been widely used for the construction of patient-specific anatomical models of the spine and intraoperative guide templates to provide personalized surgical planning and increase pedicle screw placement accuracy, only few studies have been focused on the manufacturing of spinal implants. Therefore, three-dimensional printed custom-designed intervertebral fusion devices, artificial vertebral bodies and disc substitutes for total disc replacement, along with tissue engineering strategies focused on scaffold constructs for bone and cartilage regeneration, represent a set of promising applications towards the trend of individualized patient care.

[Application of three-dimensional printing technique in orthopaedics].

PubMed

Luo, Qiang; Lau, Tak Wing; Fang, Xinshuo; Leung, Frankie

2014-03-01

To review the current progress of three-dimensional (3-D) printing technique in the clinical practice, its limitations and prospects. The recent publications associated with the clinical application of 3-D printing technique in the field of surgery, especially in orthopaedics were extensively reviewed. Currently, 3-D printing technique has been applied in orthopaedic surgery to aid diagnosis, make operative plans, and produce personalized prosthesis or implants. 3-D printing technique is a promising technique in clinical application.

Satellite land use acquisition and applications to hydrologic planning models

NASA Technical Reports Server (NTRS)

Algazi, V. R.; Suk, M.

1977-01-01

A developing operational procedure for use by the Corps of Engineers in the acquisition of land use information for hydrologic planning purposes was described. The operational conditions preclude the use of dedicated, interactive image processing facilities. Given the constraints, an approach to land use classification based on clustering seems promising and was explored in detail. The procedure is outlined and examples of application to two watersheds given.

CAD/CAM guided surgery in implant dentistry. A review of software packages and step-by-step protocols for planning surgical guides.

PubMed

Scherer, Michael D; Kattadiyil, Mathew T; Parciak, Ewa; Puri, Shweta

2014-01-01

Three-dimensional radiographic imaging for dental implant treatment planning is gaining widespread interest and popularity. However, application of the data from 30 imaging can be a complex and daunting process initially. The purpose of this article is to describe features of three software packages and the respective computerized guided surgical templates (GST) fabricated from them. A step-by-step method of interpreting and ordering a GST to simplify the process of the surgical planning and implant placement is discussed.

The relationship between executive function and fine motor control in young and older adults.

PubMed

Corti, Emily J; Johnson, Andrew R; Riddle, Hayley; Gasson, Natalie; Kane, Robert; Loftus, Andrea M

2017-01-01

The present study examined the relationship between executive function (EF) and fine motor control in young and older healthy adults. Participants completed 3 measures of executive function; a spatial working memory (SWM) task, the Stockings of Cambridge task (planning), and the Intra-Dimensional Extra-Dimensional Set-Shift task (set-shifting). Fine motor control was assessed using 3 subtests of the Purdue Pegboard (unimanual, bimanual, sequencing). For the younger adults, there were no significant correlations between measures of EF and fine motor control. For the older adults, all EFs significantly correlated with all measures of fine motor control. Three separate regressions examined whether planning, SWM and set-shifting independently predicted unimanual, bimanual, and sequencing scores for the older adults. Planning was the primary predictor of performance on all three Purdue subtests. A multiple-groups mediation model examined whether planning predicted fine motor control scores independent of participants' age, suggesting that preservation of planning ability may support fine motor control in older adults. Planning remained a significant predictor of unimanual performance in the older age group, but not bimanual or sequencing performance. The findings are discussed in terms of compensation theory, whereby planning is a key compensatory resource for fine motor control in older adults. Copyright © 2016 Elsevier B.V. All rights reserved.

Accuracy of Three-Dimensional Planning in Surgery-First Orthognathic Surgery: Planning Versus Outcome

PubMed Central

Tran, Ngoc Hieu; Tantidhnazet, Syrina; Raocharernporn, Somchart; Kiattavornchareon, Sirichai; Pairuchvej, Verasak; Wongsirichat, Natthamet

2018-01-01

Background The benefit of computer-assisted planning in orthognathic surgery (OGS) has been extensively documented over the last decade. This study aimed to evaluate the accuracy of three-dimensional (3D) virtual planning in surgery-first OGS. Methods Fifteen patients with skeletal class III malocclusion who underwent bimaxillary OGS with surgery-first approach were included. A composite skull model was reconstructed using data from cone-beam computed tomography and stereolithography from a scanned dental cast. Surgical procedures were simulated using Simplant O&O software, and the virtual plan was transferred to the operation room using 3D-printed splints. Differences of the 3D measurements between the virtual plan and postoperative results were evaluated, and the accuracy was reported using root mean square deviation (RMSD) and the Bland-Altman method. Results The virtual planning was successfully transferred to surgery. The overall mean linear difference was 0.88 mm (0.79 mm for the maxilla and 1 mm for the mandible), and the overall mean angular difference was 1.16°. The RMSD ranged from 0.86 to 1.46 mm and 1.27° to 1.45°, within the acceptable clinical criteria. Conclusion In this study, virtual surgical planning and 3D-printed surgical splints facilitated the diagnosis and treatment planning, and offered an accurate outcome in surgery-first OGS. PMID:29581806

Defining Ebstein's malformation using three-dimensional echocardiography.

PubMed

Vettukattil, Joseph J; Bharucha, Tara; Anderson, Robert H

2007-12-01

Ebstein's malformation is difficult to visualise, for both the echocardiographer and the surgeon. The essence of the problem in Ebstein's malformation is the deviation of the hingepoints of the leaflets towards the junctions of the inlet and apical trabecular parts of the right ventricle. Three-dimensional echocardiography offers new insights into the morphology and function of malformed valves, and allows elucidation of all the features. It allows clear visualisation of the valve leaflets, showing the precise morphology of the valve leaflets, the extent of their formation, the level of their attachment, and their degree of coaptation. Visualisation of the mechanism of regurgitation or stenosis is possible, as is more accurate quantification of the regurgitant jet or jets. Subchordal apparatus may be seen more clearly using three-dimensional echocardiography, and their functional anatomy understood. The multiplanar review modality allows examination of the three-dimensional data set even in patients with sub-optimal echocardiographic imaging. Previously, much of this information could only be well-understood at the time of surgery or post mortem, meaning that the majority of the specimens fully examined were at the poorly functioning end of the spectrum. This information is of use in furthering our understanding of this complex lesion as it functions in vivo, and demonstrating which anatomical pathology is significant in producing functional and physiological consequences. It is also of use for the clinician in selecting which patients are amenable to surgical intervention, for either single or biventricular repair, and for the surgeon in planning how to approach the operation. Correlation between three-dimensional echocardiographic findings and surgical findings has already been established, but the effect of this enhanced anatomical knowledge on surgical planning and surgical outcome requires further investigation.

Laser interference fringe tomography: a novel 3D imaging technique for pathology

NASA Astrophysics Data System (ADS)

Kazemzadeh, Farnoud; Haylock, Thomas M.; Chifman, Lev M.; Hajian, Arsen R.; Behr, Bradford B.; Cenko, Andrew T.; Meade, Jeff T.; Hendrikse, Jan

2011-03-01

Laser interference fringe tomography (LIFT) is within the class of optical imaging devices designed for in vivo and ex vivo medical imaging applications. LIFT is a very simple and cost-effective three-dimensional imaging device with performance rivaling some of the leading three-dimensional imaging devices used for histology. Like optical coherence tomography (OCT), it measures the reflectivity as a function of depth within a sample and is capable of producing three-dimensional images from optically scattering media. LIFT has the potential capability to produce high spectral resolution, full-color images. The optical design of LIFT along with the planned iterations for improvements and miniaturization are presented and discussed in addition to the theoretical concepts and preliminary imaging results of the device.

Analysis of satellite servicing cost benefits

NASA Technical Reports Server (NTRS)

Builteman, H. O.

1982-01-01

Under the auspices of NASA/JSC a methodology was developed to estimate the value of satellite servicing to the user community. Time and funding precluded the development of an exhaustive computer model; instead, the concept of Design Reference Missions was involved. In this approach, three space programs were analyzed for various levels of servicing. The programs selected fall into broad categories which include 80 to 90% of the missions planned between now and the end of the century. Of necessity, the extrapolation of the three program analyses to the user community as a whole depends on an average mission model and equivalency projections. The value of the estimated cost benefits based on this approach depends largely on how well the equivalency assumptions and the mission model match the real world. A careful definition of all assumptions permits the analysis to be extended to conditions beyond the scope of this study.

Confounding factors in diagnosing brain death: a case report.

PubMed

Burns, Jeffrey M; Login, Ivan S

2002-06-26

Brain death is strictly defined medically and legally. This diagnosis depends on three cardinal neurological features: coma, absent brainstem reflexes, and apnea. The diagnosis can only be made, however, in the absence of intoxication, hypothermia, or certain medical illnesses. A patient with severe hypoxic-ischemic brain injury met the three cardinal neurological features of brain death but concurrent profound hypothyroidism precluded the diagnosis. Our clinical and ethical decisions were further challenged by another facet of this complex case. Although her brain damage indicated a hopeless prognosis, we could not discontinue care based on futility because the only known surrogate was mentally retarded and unable to participate in medical planning. The presence of certain medical conditions prohibits a diagnosis of brain death, which is a medicolegal diagnosis of death, not a prediction or forecast of future outcome. While prognostication is important in deciding to withdraw care, it is not a component in diagnosing brain death.

Three-Dimensional Printing in Orthopedic Surgery.

PubMed

Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H

2015-11-01

Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions. Copyright 2015, SLACK Incorporated.

Three-Dimensional Implant Positioning with a Piezosurgery Implant Site Preparation Technique and an Intraoral Surgical Navigation System: Case Report.

PubMed

Pellegrino, Gerardo; Taraschi, Valerio; Vercellotti, Tomaso; Ben-Nissan, Besim; Marchetti, Claudio

This case report describes new implant site preparation techniques joining the benefits of using an intraoral navigation system to optimize three-dimensional implant site positioning in combination with an ultrasonic osteotomy. A report of five patients is presented, and the implant positions as planned in the navigation software with the postoperative scan image were compared. The preliminary results are useful, although further clinical studies with larger populations are needed to confirm these findings.

Intensity-Modulated Radiotherapy Might Increase Pneumonitis Risk Relative to Three-Dimensional Conformal Radiotherapy in Patients Receiving Combined Chemotherapy and Radiotherapy: A Modeling Study of Dose Dumping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogelius, Ivan S.; Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI; Department of Radiation Oncology, Rigshospitalet

2011-07-01

Purpose: To model the possible interaction between cytotoxic chemotherapy and the radiation dose distribution with respect to the risk of radiation pneumonitis. Methods and Materials: A total of 18 non-small-cell lung cancer patients previously treated with helical tomotherapy at the University of Wisconsin were selected for the present modeling study. Three treatment plans were considered: the delivered tomotherapy plans; a three-dimensional conformal radiotherapy (3D-CRT) plan; and a fixed-field intensity-modulated radiotherapy (IMRT) plan. The IMRT and 3D-CRT plans were generated specifically for the present study. The plans were optimized without adjusting for the chemotherapy effect. The effect of chemotherapy was modeledmore » as an independent cell killing process by considering a uniform chemotherapy equivalent radiation dose added to all voxels of the organ at risk. The risk of radiation pneumonitis was estimated for all plans using the Lyman and the critical volume models. Results: For radiotherapy alone, the critical volume model predicts that the two IMRT plans are associated with a lower risk of radiation pneumonitis than the 3D-CRT plan. However, when the chemotherapy equivalent radiation dose exceeds a certain threshold, the radiation pneumonitis risk after IMRT is greater than after 3D-CRT. This threshold dose is in the range estimated from clinical chemoradiotherapy data sets. Conclusions: Cytotoxic chemotherapy might affect the relative merit of competing radiotherapy plans. More work is needed to improve our understanding of the interaction between chemotherapy and the radiation dose distribution in clinical settings.« less

Interactive 3-D graphics workstations in stereotaxy: clinical requirements, algorithms, and solutions

NASA Astrophysics Data System (ADS)

Ehricke, Hans-Heino; Daiber, Gerhard; Sonntag, Ralf; Strasser, Wolfgang; Lochner, Mathias; Rudi, Lothar S.; Lorenz, Walter J.

1992-09-01

In stereotactic treatment planning the spatial relationships between a variety of objects has to be taken into account in order to avoid destruction of vital brain structures and rupture of vasculature. The visualization of these highly complex relations may be supported by 3-D computer graphics methods. In this context the three-dimensional display of the intracranial vascular tree and additional objects, such as neuroanatomy, pathology, stereotactic devices, or isodose surfaces, is of high clinical value. We report an advanced rendering method for a depth-enhanced maximum intensity projection from magnetic resonance angiography (MRA) and a walk-through approach to the analysis of MRA volume data. Furthermore, various methods for a multiple-object 3-D rendering in stereotaxy are discussed. The development of advanced applications in medical imaging can hardly be successful if image acquisition problems are disregarded. We put particular emphasis on the use of conventional MRI and MRA for stereotactic guidance. The problem of MR distortion is discussed and a novel three- dimensional approach to the quantification and correction of the distortion patterns is presented. Our results suggest that the sole use of MR for stereotactic guidance is highly practical. The true three-dimensionality of the acquired datasets opens up new perspectives to stereotactic treatment planning. For the first time it is possible now to integrate all the necessary information into 3-D scenes, thus enabling an interactive 3-D planning.

Algorithm for planning a double-jaw orthognathic surgery using a computer-aided surgical simulation (CASS) protocol. Part 2: three-dimensional cephalometry

PubMed Central

Xia, J. J.; Gateno, J.; Teichgraeber, J. F.; Yuan, P.; Li, J.; Chen, K.-C.; Jajoo, A.; Nicol, M.; Alfi, D. M.

2015-01-01

Three-dimensional (3D) cephalometry is not as simple as just adding a ‘third’ dimension to a traditional two-dimensional cephalometric analysis. There are more complex issues in 3D analysis. These include how reference frames are created, how size, position, orientation and shape are measured, and how symmetry is assessed. The main purpose of this article is to present the geometric principles of 3D cephalometry. In addition, the Gateno–Xia cephalometric analysis is presented; this is the first 3D cephalometric analysis to observe these principles. PMID:26573563

Maritime Cast Shop Integrated Improvement Plan

DTIC Science & Technology

2010-08-20

preclude increasing non-value added revert inventory. A second best practice in this area is the consumption and reuse of revert produced from pigging...alloy elements–minimize metallic oxidation.  Inert gas cost—maximize nitrogen use instead of the more costly argon gas use.  Refractory consumption

Proactive restoration: planning, implementation, and early results of silvicultural strategies for increasing resilience against gypsy moth infestation in upland oak forests on the Daniel Boone National Forest, Kentucky

Treesearch

Callie Schweitzer; Stacy L. Clark; Kurt W. Gottschalk; Jeff Stringer; Robbie Sitzlar

2014-01-01

Determining targets in forest restoration is a complicated task that can be facilitated by cooperative partnerships. Too often restoration plans are implemented after adverse events that cause widespread tree mortality, such as drought or insect outbreaks, have occurred. Reactive management precludes the use of preemptive management techniques that can result in more...

Comparative evaluation of two-dimensional radiography and three dimensional computed tomography based dose-volume parameters for high-dose-rate intracavitary brachytherapy of cervical cancer: a prospective study.

PubMed

Madan, Renu; Pathy, Sushmita; Subramani, Vellaiyan; Sharma, Seema; Mohanti, Bidhu Kalyan; Chander, Subhash; Thulkar, Sanjay; Kumar, Lalit; Dadhwal, Vatsla

2014-01-01

Dosimetric comparison of two dimensional (2D) radiography and three-dimensional computed tomography (3D-CT) based dose distributions with high-dose-rate (HDR) intracavitry radiotherapy (ICRT) for carcinoma cervix, in terms of target coverage and doses to bladder and rectum. Sixty four sessions of HDR ICRT were performed in 22 patients. External beam radiotherapy to pelvis at a dose of 50 Gray in 27 fractions followed by HDR ICRT, 21 Grays to point A in 3 sessions, one week apart was planned . All patients underwent 2D-orthogonal and 3D-CT simulation for each session. Treatment plans were generated using 2D-orthogonal images and dose prescription was made at point A. 3D plans were generated using 3D-CT images after delineating target volume and organs at risk. Comparative evaluation of 2D and 3D treatment planning was made for each session in terms of target coverage (dose received by 90%, 95% and 100% of the target volume: D90, D95 and D100 respectively) and doses to bladder and rectum: ICRU-38 bladder and rectum point dose in 2D planning and dose to 0.1cc, 1cc, 2cc, 5cc, and 10cc of bladder and rectum in 3D planning. Mean doses received by 100% and 90% of the target volume were 4.24 ± 0.63 and 4.9 ± 0.56 Gy respectively. Doses received by 0.1cc, 1cc and 2cc volume of bladder were 2.88 ± 0.72, 2.5 ± 0.65 and 2.2 ± 0.57 times more than the ICRU bladder reference point. Similarly, doses received by 0.1cc, 1cc and 2cc of rectum were 1.80 ± 0.5, 1.48 ± 0.41 and 1.35 ± 0.37 times higher than ICRU rectal reference point. Dosimetric comparative evaluation of 2D and 3D CT based treatment planning for the same brachytherapy session demonstrates underestimation of OAR doses and overestimation of target coverage in 2D treatment planning.

Current situation of high-dose-rate brachytherapy for cervical cancer in Brazil*

PubMed Central

da Silva, Rogério Matias Vidal; Pinezi, Juliana Castro Dourado; Macedo, Luiz Eduardo Andrade; Souza, Divanízia do Nascimento

2014-01-01

Objective To assess the current situation of high-dose-rate (HDR) brachytherapy for cancer of the cervix in Brazil, regarding apparatuses, planning methods, prescription, fractionation schedule and evaluation of dose in organs at risk. Materials and Methods In the period between March/2012 and May/2013, a multiple choice questionnaire was developed and sent to 89 Brazilian hospitals which perform HDR brachytherapy. Results Sixty-one services answered the questionnaire. All regions of the country experienced a sharp increase in the number of HDR brachytherapy services in the period from 2001 to 2013. As regards planning, although a three-dimensional planning software was available in 91% of the centers, conventional radiography was mentioned by 92% of the respondents as their routine imaging method for such a purpose. Approximately 35% of respondents said that brachytherapy sessions are performed after teletherapy. The scheme of four 7 Gy intracavitary insertions was mentioned as the most frequently practiced. Conclusion The authors observed that professionals have difficulty accessing adjuvant three-dimensional planning tools such as computed tomography and magnetic resonance imaging. PMID:25741073

[Localization of perforators in the lower leg by digital antomy imaging methods].

PubMed

Wei, Peng; Ma, Liang-Liang; Fang, Ye-Dong; Xia, Wei-Zhi; Ding, Mao-Chao; Mei, Jin

2012-03-01

To offer both the accurate three-dimensional anatomical information and algorithmic morphology of perforators in the lower leg for perforator flaps design. The cadaver was injected with a modified lead oxide-gelatin mixture. Radiography was first performed and the images were analyzed using the software Photoshop and Scion Image. Then spiral CT scan was also performed and 3-dimensional images were reconstructed with MIMICS 10.01 software. There are (27 +/- 4) perforators whose outer diameter > or = 0.5 mm ( average, 0.8 +/- 0.2 mm). The average pedicle length within the superficial fascia is (37.3 +/- 18.6) mm. The average supplied area of each perforator is (49.5 +/- 25.5) cm2. The three-dimensional model displayed accurate morphology structure and three-dimensional distribution of the perforator-to- perforator and perforator-to-source artery. The 3D reconstruction model can clearly show the geometric, local details and three-dimensional distribution. It is a considerable method for the study of morphological characteristics of the individual perforators in human calf and preoperative planning of the perforator flap.

Nondestructive cryomicro-CT imaging enables structural and molecular analysis of human lung tissue.

PubMed

Vasilescu, Dragoş M; Phillion, André B; Tanabe, Naoya; Kinose, Daisuke; Paige, David F; Kantrowitz, Jacob J; Liu, Gang; Liu, Hanqiao; Fishbane, Nick; Verleden, Stijn E; Vanaudenaerde, Bart M; Lenburg, Marc; Stevenson, Christopher S; Spira, Avrum; Cooper, Joel D; Hackett, Tillie-Louise; Hogg, James C

2017-01-01

Micro-computed tomography (CT) enables three-dimensional (3D) imaging of complex soft tissue structures, but current protocols used to achieve this goal preclude cellular and molecular phenotyping of the tissue. Here we describe a radiolucent cryostage that permits micro-CT imaging of unfixed frozen human lung samples at an isotropic voxel size of (11 µm) 3 under conditions where the sample is maintained frozen at -30°C during imaging. The cryostage was tested for thermal stability to maintain samples frozen up to 8 h. This report describes the methods used to choose the materials required for cryostage construction and demonstrates that whole genome mRNA integrity and expression are not compromised by exposure to micro-CT radiation and that the tissue can be used for immunohistochemistry. The new cryostage provides a novel method enabling integration of 3D tissue structure with cellular and molecular analysis to facilitate the identification of molecular determinants of disease. The described micro-CT cryostage provides a novel way to study the three-dimensional lung structure preserved without the effects of fixatives while enabling subsequent studies of the cellular matrix composition and gene expression. This approach will, for the first time, enable researchers to study structural changes of lung tissues that occur with disease and correlate them with changes in gene or protein signatures. Copyright © 2017 the American Physiological Society.

Metamorphosis revealed: time-lapse three-dimensional imaging inside a living chrysalis

PubMed Central

Lowe, Tristan; Garwood, Russell J.; Simonsen, Thomas J.; Bradley, Robert S.; Withers, Philip J.

2013-01-01

Studies of model insects have greatly increased our understanding of animal development. Yet, they are limited in scope to this small pool of model species: a small number of representatives for a hyperdiverse group with highly varied developmental processes. One factor behind this narrow scope is the challenging nature of traditional methods of study, such as histology and dissection, which can preclude quantitative analysis and do not allow the development of a single individual to be followed. Here, we use high-resolution X-ray computed tomography (CT) to overcome these issues, and three-dimensionally image numerous lepidopteran pupae throughout their development. The resulting models are presented in the electronic supplementary material, as are figures and videos, documenting a single individual throughout development. They provide new insight and details of lepidopteran metamorphosis, and allow the measurement of tracheal and gut volume. Furthermore, this study demonstrates early and rapid development of the tracheae, which become visible in scans just 12 h after pupation. This suggests that there is less remodelling of the tracheal system than previously expected, and is methodologically important because the tracheal system is an often-understudied character system in development. In the future, this form of time-lapse CT-scanning could allow faster and more detailed developmental studies on a wider range of taxa than is presently possible. PMID:23676900

Log corrections to entropy of three dimensional black holes with soft hair

NASA Astrophysics Data System (ADS)

Grumiller, Daniel; Perez, Alfredo; Tempo, David; Troncoso, Ricardo

2017-08-01

We calculate log corrections to the entropy of three-dimensional black holes with "soft hairy" boundary conditions. Their thermodynamics possesses some special features that preclude a naive direct evaluation of these corrections, so we follow two different approaches. The first one exploits that the BTZ black hole belongs to the spectrum of Brown-Henneaux as well as soft hairy boundary conditions, so that the respective log corrections are related through a suitable change of the thermodynamic ensemble. In the second approach the analogue of modular invariance is considered for dual theories with anisotropic scaling of Lifshitz type with dynamical exponent z at the boundary. On the gravity side such scalings arise for KdV-type boundary conditions, which provide a specific 1-parameter family of multi-trace deformations of the usual AdS3/CFT2 setup, with Brown-Henneaux corresponding to z = 1 and soft hairy boundary conditions to the limiting case z → 0+. Both approaches agree in the case of BTZ black holes for any non-negative z. Finally, for soft hairy boundary conditions we show that not only the leading term, but also the log corrections to the entropy of black flowers endowed with affine û (1) soft hair charges exclusively depend on the zero modes and hence coincide with the ones for BTZ black holes.

Choice Inconsistencies among the Elderly: Evidence from Plan Choice in the Medicare Part D Program: Comment.

PubMed

Ketcham, Jonathan D; Kuminoff, Nicolai V; Powers, Christopher A

2016-12-01

Consumers' enrollment decisions in Medicare Part D can be explained by Abaluck and Gruber’s (2011) model of utility maximization with psychological biases or by a neoclassical version of their model that precludes such biases. We evaluate these competing hypotheses by applying nonparametric tests of utility maximization and model validation tests to administrative data. We find that 79 percent of enrollment decisions from 2006 to 2010 satisfied basic axioms of consumer theory under the assumption of full information. The validation tests provide evidence against widespread psychological biases. In particular, we find that precluding psychological biases improves the structural model's out-of-sample predictions for consumer behavior.

Three-Dimensional Printing: An Aid to Epidural Access for Neuromodulation.

PubMed

Taverner, Murray G; Monagle, John P

2017-08-01

The case report details to use of three-dimensional (3D) printing as an aid to neuromodulation. A patient is described in whom previous attempts at spinal neuromodulation had failed due to lack of epidural or intrathecal access, and the use of a 3D printed model allowed for improved planning and ultimately, success. Successful spinal cord stimulation was achieved with the plan developed by access to a 3D model of the patient's spine. Neuromodulation techniques can provide the optimal analgesic techniques for individual patients. At times these can fail due to lack of access to the site for intervention, in this case epidural access. 3D printing may provide additional information to improve the likelihood of access when anatomy is distorted and standard approaches prove difficult. © 2017 International Neuromodulation Society.

Three-dimensional virtual operations can facilitate complicated surgical planning for the treatment of patients with jaw deformities associated with facial asymmetry: a case report.

PubMed

Hara, Shingo; Mitsugi, Masaharu; Kanno, Takahiro; Nomachi, Akihiko; Wajima, Takehiko; Tatemoto, Yukihiro

2013-09-01

This article describes a case we experienced in which good postsurgical facial profiles were obtained for a patient with jaw deformities associated with facial asymmetry, by implementing surgical planning with SimPlant OMS. Using this method, we conducted LF1 osteotomy, intraoral vertical ramus osteotomy (IVRO), sagittal split ramus osteotomy (SSRO), mandibular constriction and mandibular border genioplasty. Not only did we obtain a class I occlusal relationship, but the complicated surgery also improved the asymmetry of the frontal view, as well as of the profile view, of the patient. The virtual operation using three-dimensional computed tomography (3D-CT) could be especially useful for the treatment of patients with jaw deformities associated with facial asymmetry.

Three-dimensional virtual operations can facilitate complicated surgical planning for the treatment of patients with jaw deformities associated with facial asymmetry: a case report

PubMed Central

Hara, Shingo; Mitsugi, Masaharu; Kanno, Takahiro; Nomachi, Akihiko; Wajima, Takehiko; Tatemoto, Yukihiro

2013-01-01

This article describes a case we experienced in which good postsurgical facial profiles were obtained for a patient with jaw deformities associated with facial asymmetry, by implementing surgical planning with SimPlant OMS. Using this method, we conducted LF1 osteotomy, intraoral vertical ramus osteotomy (IVRO), sagittal split ramus osteotomy (SSRO), mandibular constriction and mandibular border genioplasty. Not only did we obtain a class I occlusal relationship, but the complicated surgery also improved the asymmetry of the frontal view, as well as of the profile view, of the patient. The virtual operation using three-dimensional computed tomography (3D-CT) could be especially useful for the treatment of patients with jaw deformities associated with facial asymmetry. PMID:23907678

Multiple two-dimensional versus three-dimensional PTV definition in treatment planning for conformal radiotherapy.

PubMed

Stroom, J C; Korevaar, G A; Koper, P C; Visser, A G; Heijmen, B J

1998-06-01

To demonstrate the need for a fully three-dimensional (3D) computerized expansion of the gross tumour volume (GTV) or clinical target volume (CTV), as delineated by the radiation oncologist on CT slices, to obtain the proper planning target volume (PTV) for treatment planning according to the ICRU-50 recommendations. For 10 prostate cancer patients two PTVs have been determined by expansion of the GTV with a 1.5 cm margin, i.e. a 3D PTV and a multiple 2D PTV. The former was obtained by automatically adding the margin while accounting in 3D for GTV contour differences in neighbouring slices. The latter was generated by automatically adding the 1.5 cm margin to the GTV in each CT slice separately; the resulting PTV is a computer simulation of the PTV that a radiation oncologist would obtain with (the still common) manual contouring in CT slices. For each patient the two PTVs were compared to assess the deviations of the multiple 2D PTV from the 3D PTV. For both PTVs conformal plans were designed using a three-field technique with fixed block margins. For each patient dose-volume histograms and tumour control probabilities (TCPs) of the (correct) 3D PTV were calculated, both for the plan designed for this PTV and for the treatment plan based on the (deviating) 2D PTV. Depending on the shape of the GTV, multiple 2D PTV generation could locally result in a 1 cm underestimation of the GTV-to-PTV margin. The deviations occurred predominantly in the cranio-caudal direction at locations where the GTV contour shape varies significantly from slice to slice. This could lead to serious underdosage and to a TCP decrease of up to 15%. A full 3D GTV-to-PTV expansion should be applied in conformal radiotherapy to avoid underdosage.

9 CFR 149.7 - Recordkeeping at site.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... If the carcass storage facility or composting facility is located on the site, then the animal disposal plan must provide for a storage or composting facility that precludes rodent or wildlife contact... swine and other mammals by rendering, incineration, composting, burial, or other means, as allowed by...

Intensity-modulated radiation therapy: a review with a physics perspective.

PubMed

Cho, Byungchul

2018-03-01

Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.

Dimensional metrology of lab-on-a-chip internal structures: a comparison of optical coherence tomography with confocal fluorescence microscopy.

PubMed

Reyes, D R; Halter, M; Hwang, J

2015-07-01

The characterization of internal structures in a polymeric microfluidic device, especially of a final product, will require a different set of optical metrology tools than those traditionally used for microelectronic devices. We demonstrate that optical coherence tomography (OCT) imaging is a promising technique to characterize the internal structures of poly(methyl methacrylate) devices where the subsurface structures often cannot be imaged by conventional wide field optical microscopy. The structural details of channels in the devices were imaged with OCT and analyzed with an in-house written ImageJ macro in an effort to identify the structural details of the channel. The dimensional values obtained with OCT were compared with laser-scanning confocal microscopy images of channels filled with a fluorophore solution. Attempts were also made using confocal reflectance and interferometry microscopy to measure the channel dimensions, but artefacts present in the images precluded quantitative analysis. OCT provided the most accurate estimates for the channel height based on an analysis of optical micrographs obtained after destructively slicing the channel with a microtome. OCT may be a promising technique for the future of three-dimensional metrology of critical internal structures in lab-on-a-chip devices because scans can be performed rapidly and noninvasively prior to their use. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Three-dimensional spiral CT for neurosurgical planning.

PubMed

Klein, H M; Bertalanffy, H; Mayfrank, L; Thron, A; Günther, R W; Gilsbach, J M

1994-08-01

We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important.

Spatiotemporal Features of the Three-Dimensional Architectural Landscape in Qingdao, China.

PubMed

Zhang, Peifeng

2015-01-01

The evolution and development of the three-dimensional (3D) architectural landscape is the basis of proper urban planning, eco-environment construction and the improvement of environmental quality. This paper presents the spatiotemporal characteristics of the 3D architectural landscape of the Shinan and Shibei districts in Qingdao, China, based on buildings' 3D information extracted from Quickbird images from 2003 to 2012, supported by Barista, landscape metrics and GIS. The results demonstrated that: (1) Shinan and Shibei districts expanded vertically and urban land use intensity increased noticeably from year to year. (2) Significant differences in the 3D architectural landscape existed among the western, central and eastern regions, and among the 26 sub-districts over the study period. The differentiation was consistent with the diverse development history, function and planning of the two districts. Finally, we found that population correlates positively with the variation in the 3D architectural landscape. This research provides an important reference for related studies, urban planning and eco-city construction.

Preoperative planning of thoracic surgery with use of three-dimensional reconstruction, rapid prototyping, simulation and virtual navigation

PubMed Central

Heuts, Samuel; Maessen, Jos G.

2016-01-01

For the past decades, surgeries have become more complex, due to the increasing age of the patient population referred for thoracic surgery, more complex pathology and the emergence of minimally invasive thoracic surgery. Together with the early detection of thoracic disease as a result of innovations in diagnostic possibilities and the paradigm shift to personalized medicine, preoperative planning is becoming an indispensable and crucial aspect of surgery. Several new techniques facilitating this paradigm shift have emerged. Pre-operative marking and staining of lesions are already a widely accepted method of preoperative planning in thoracic surgery. However, three-dimensional (3D) image reconstructions, virtual simulation and rapid prototyping (RP) are still in development phase. These new techniques are expected to become an important part of the standard work-up of patients undergoing thoracic surgery in the future. This review aims at graphically presenting and summarizing these new diagnostic and therapeutic tools PMID:29078505

Spatiotemporal Features of the Three-Dimensional Architectural Landscape in Qingdao, China

PubMed Central

Zhang, Peifeng

2015-01-01

The evolution and development of the three-dimensional (3D) architectural landscape is the basis of proper urban planning, eco-environment construction and the improvement of environmental quality. This paper presents the spatiotemporal characteristics of the 3D architectural landscape of the Shinan and Shibei districts in Qingdao, China, based on buildings’ 3D information extracted from Quickbird images from 2003 to 2012, supported by Barista, landscape metrics and GIS. The results demonstrated that: (1) Shinan and Shibei districts expanded vertically and urban land use intensity increased noticeably from year to year. (2) Significant differences in the 3D architectural landscape existed among the western, central and eastern regions, and among the 26 sub-districts over the study period. The differentiation was consistent with the diverse development history, function and planning of the two districts. Finally, we found that population correlates positively with the variation in the 3D architectural landscape. This research provides an important reference for related studies, urban planning and eco-city construction. PMID:26361016

A cosmic web filament revealed in Lyman-α emission around a luminous high-redshift quasar.

PubMed

Cantalupo, Sebastiano; Arrigoni-Battaia, Fabrizio; Prochaska, J Xavier; Hennawi, Joseph F; Madau, Piero

2014-02-06

Simulations of structure formation in the Universe predict that galaxies are embedded in a 'cosmic web', where most baryons reside as rarefied and highly ionized gas. This material has been studied for decades in absorption against background sources, but the sparseness of these inherently one-dimensional probes preclude direct constraints on the three-dimensional morphology of the underlying web. Here we report observations of a cosmic web filament in Lyman-α emission, discovered during a survey for cosmic gas fluorescently illuminated by bright quasars at redshift z ≈ 2.3. With a linear projected size of approximately 460 physical kiloparsecs, the Lyman-α emission surrounding the radio-quiet quasar UM 287 extends well beyond the virial radius of any plausible associated dark-matter halo and therefore traces intergalactic gas. The estimated cold gas mass of the filament from the observed emission-about 10(12.0 ± 0.5)/C(1/2) solar masses, where C is the gas clumping factor-is more than ten times larger than what is typically found in cosmological simulations, suggesting that a population of intergalactic gas clumps with subkiloparsec sizes may be missing in current numerical models.

Capture and Three Dimensional Projection of New South Wales Strata Plans in Landxml Format

NASA Astrophysics Data System (ADS)

Harding, B.; Foreman, A.

2017-10-01

New South Wales is embarking on a major reform program named Cadastre NSW. This reform aims to move to a single source of truth for the digital representation of cadastre. The current lack of a single source cadastre has hindered users from government and industry due to duplication of effort and misalignment between databases from different sources. For this reform to be successful, there are some challenges that need to be addressed. "Cadastre 2034 - Powering Land & Real Property" (2015) published by the Intergovernmental Committee on Surveying and Mapping (ICSM) identifies that current cadastres do not represent real property in three dimensions. In future vertical living lifestyles will create complex property scenarios that the Digital Cadastral Database (DCDB) will need to contend with. While the NSW DCDB currently holds over 3 million lots and 5 million features, one of its limitations is that it does not indicate land ownership above or below the ground surface. NSW Spatial Services is currently capturing survey plans into LandXML format. To prepare for the future, research is being undertaken to also capture multi-level Strata Plans through a modified recipe. During this research, multiple Strata Plans representing a range of ages and development types have been investigated and converted to LandXML. Since it is difficult to visualise the plans in a two dimensional format, quality control purposes require a method to display these plans in three dimensions. Overall investigations have provided Spatial Services with enough information to confirm that the capture and display of Strata Plans in the LandXML format is possible.

An Energy Model of Place Cell Network in Three Dimensional Space.

PubMed

Wang, Yihong; Xu, Xuying; Wang, Rubin

2018-01-01

Place cells are important elements in the spatial representation system of the brain. A considerable amount of experimental data and classical models are achieved in this area. However, an important question has not been addressed, which is how the three dimensional space is represented by the place cells. This question is preliminarily surveyed by energy coding method in this research. Energy coding method argues that neural information can be expressed by neural energy and it is convenient to model and compute for neural systems due to the global and linearly addable properties of neural energy. Nevertheless, the models of functional neural networks based on energy coding method have not been established. In this work, we construct a place cell network model to represent three dimensional space on an energy level. Then we define the place field and place field center and test the locating performance in three dimensional space. The results imply that the model successfully simulates the basic properties of place cells. The individual place cell obtains unique spatial selectivity. The place fields in three dimensional space vary in size and energy consumption. Furthermore, the locating error is limited to a certain level and the simulated place field agrees to the experimental results. In conclusion, this is an effective model to represent three dimensional space by energy method. The research verifies the energy efficiency principle of the brain during the neural coding for three dimensional spatial information. It is the first step to complete the three dimensional spatial representing system of the brain, and helps us further understand how the energy efficiency principle directs the locating, navigating, and path planning function of the brain.

Three-dimensional surgical simulation.

PubMed

Cevidanes, Lucia H C; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael

2010-09-01

In this article, we discuss the development of methods for computer-aided jaw surgery, which allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3-dimensional surface models from cone-beam computed tomography, dynamic cephalometry, semiautomatic mirroring, interactive cutting of bone, and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intraoperative guidance. The system provides further intraoperative assistance with a computer display showing jaw positions and 3-dimensional positioning guides updated in real time during the surgical procedure. The computer-aided surgery system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training, and assessing the difficulties of the surgical procedures before the surgery. Computer-aided surgery can make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

42 CFR 424.22 - Requirements for home health services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... underlying condition or complication requires a registered nurse to ensure that essential non-skilled care is... medicine, and who is not precluded from performing this function under paragraph (d) of this section. (A doctor of podiatric medicine may perform only plan of treatment functions that are consistent with the...

42 CFR 424.22 - Requirements for home health services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... underlying condition or complication requires a registered nurse to ensure that essential non-skilled care is... medicine, and who is not precluded from performing this function under paragraph (d) of this section. (A doctor of podiatric medicine may perform only plan of treatment functions that are consistent with the...

3D-FFT for Signature Detection in LWIR Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medvick, Patricia A.; Lind, Michael A.; Mackey, Patrick S.

Improvements in analysis detection exploitation are possible by applying whitened matched filtering within the Fourier domain to hyperspectral data cubes. We describe an implementation of a Three Dimensional Fast Fourier Transform Whitened Matched Filter (3DFFTMF) approach and, using several example sets of Long Wave Infra Red (LWIR) data cubes, compare the results with those from standard Whitened Matched Filter (WMF) techniques. Since the variability in shape of gaseous plumes precludes the use of spatial conformation in the matched filtering, the 3DFFTMF results were similar to those of two other WMF methods. Including a spatial low-pass filter within the Fourier spacemore » can improve signal to noise ratios and therefore improve detection limit by facilitating the mitigation of high frequency clutter. The improvement only occurs if the low-pass filter diameter is smaller than the plume diameter.« less

Glycerophosphate-based chitosan thermosensitive hydrogels and their biomedical applications.

PubMed

Zhou, Hui Yun; Jiang, Ling Juan; Cao, Pei Pei; Li, Jun Bo; Chen, Xi Guang

2015-03-06

Chitosan is non-toxic, biocompatible and biodegradable polysaccharide composed of glucosamine and derived by deacetylation of chitin. Chitosan thermosensitive hydrogel has been developed to form a gel in situ, precluding the need for surgical implantation. In this review, the recent advances in chitosan thermosensitive hydrogels based on different glycerophosphate are summarized. The hydrogel is prepared with chitosan and β-glycerophosphate or αβ-glycerophosphate which is liquid at room temperature and transits into gel as temperature increases. The gelation mechanism may involve multiple interactions between chitosan, glycerophosphate, and water. The solution behavior, rheological and physicochemical properties, and gelation process of the hydrogel are affected not only by the molecule weight, deacetylation degree, and concentration of chitosan, but also by the kind and concentration of glycerophosphate. The properties and the three-dimensional networks of the hydrogel offer them wide applications in biomedical field including local drug delivery and tissue engineering. Copyright © 2014 Elsevier Ltd. All rights reserved.

[An Experimental Set-Up for Navigated-Contrast-Agent and Radiation Sparing Endovascular Aortic Repair (Nav-CARS EVAR)].

PubMed

Horn, M; Nolde, J; Goltz, J P; Barkhausen, J; Schade, W; Waltermann, C; Modersitzki, J; Olesch, J; Papenberg, N; Keck, T; Kleemann, M

2015-10-01

Over the last decade endovascular stenting of aortic aneurysm (EVAR) has been developed from single centre experiences to a standard procedure. With increasing clinical expertise and medical technology advances treatment of even complex aneurysms are feasible by endovascular methods. One integral part for the success of this minimally invasive procedure is innovative and improved vascular imaging to generate exact measurements and correct placement of stent prosthesis. One of the greatest difficulty in learning and performing this endovascular therapy is the fact that the three-dimensional vascular tree has to be overlaid with the two-dimensional angiographic scene by the vascular surgeon. We report the development of real-time navigation software, which allows a three-dimensional endoluminal view of the vascular system during an EVAR procedure in patients with infrarenal aortic aneurysm. We used the preoperative planning CT angiography for three-dimensional reconstruction of aortic anatomy by volume-rendered segmentation. At the beginning of the intervention the relevant landmarks are matched in real-time with the two-dimensional angiographic scene. During the intervention the software continously registers the position of the guide-wire or the stent. An additional 3D-screen shows the generated endoluminal view during the whole intervention in real-time. We examined the combination of hardware and software components including complex image registration and fibre optic sensor technology (fibre-bragg navigation) with integration in stent graft introducer sheaths using patient-specific vascular phantoms in an experimental setting. From a technical point of view the feasibility of fibre-Bragg navigation has been proven in our experimental setting with patient-based vascular models. Three-dimensional preoperative planning including registration and simulation of virtual angioscopy in real time are realised. The aim of the Nav-CARS-EVAR concept is reduction of contrast medium and radiation dose by a three-dimensional navigation during the EVAR procedure. To implement fibre-Bragg navigation further experimental studies are necessary to verify accuracy before clinical application. Georg Thieme Verlag KG Stuttgart · New York.

Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy.

PubMed

Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

2016-02-27

Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV coverage and the sparing of the lung and heart. However, the CK may be used to reduce high doses received by the NTBTV more efficiently. Robotic stereotactic radiotherapy may be used for APBI to more efficiently spare the NTBTV and improve cosmetic results of APBI.

The possible usability of three-dimensional cone beam computed dental tomography in dental research

NASA Astrophysics Data System (ADS)

Yavuz, I.; Rizal, M. F.; Kiswanjaya, B.

2017-08-01

The innovations and advantages of three-dimensional cone beam computed dental tomography (3D CBCT) are continually growing for its potential use in dental research. Imaging techniques are important for planning research in dentistry. Newly improved 3D CBCT imaging systems and accessory computer programs have recently been proven effective for use in dental research. The aim of this study is to introduce 3D CBCT and open a window for future research possibilities that should be given attention in dental research.

Application Of Three-Dimensional Videography To Human Motion Studies: Constraints, Assumptions, And Mathematics

NASA Astrophysics Data System (ADS)

Rab, George T.

1988-02-01

Three-dimensional human motion analysis has been used for complex kinematic description of abnormal gait in children with neuromuscular disease. Multiple skin markers estimate skeletal segment position, and a sorting and smoothing routine provides marker trajectories. The position and orientation of the moving skeleton in space are derived mathematically from the marker positions, and joint motions are calculated from the Eulerian transformation matrix between linked proximal and distal skeletal segments. Reproduceability has been excellent, and the technique has proven to be a useful adjunct to surgical planning.

Mobile robots IV; Proceedings of the Meeting, Philadelphia, PA, Nov. 6, 7, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolfe, W.J.; Chun, W.H.

1990-01-01

The present conference on mobile robot systems discusses high-speed machine perception based on passive sensing, wide-angle optical ranging, three-dimensional path planning for flying/crawling robots, navigation of autonomous mobile intelligence in an unstructured natural environment, mechanical models for the locomotion of a four-articulated-track robot, a rule-based command language for a semiautonomous Mars rover, and a computer model of the structured light vision system for a Mars rover. Also discussed are optical flow and three-dimensional information for navigation, feature-based reasoning trail detection, a symbolic neural-net production system for obstacle avoidance and navigation, intelligent path planning for robot navigation in an unknown environment,more » behaviors from a hierarchical control system, stereoscopic TV systems, the REACT language for autonomous robots, and a man-amplifying exoskeleton.« less

Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT).

PubMed

Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

2013-12-01

Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147-53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose-volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

PubMed Central

Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

2013-01-01

Introduction Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. Methods A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. Results The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. Conclusion The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques. PMID:26229623

Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham

Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRTmore » plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.« less

Accuracy of virtual surgical planning of orthognathic surgery with aid of CAD/CAM fabricated surgical splint-A novel 3D analyzing algorithm.

PubMed

Chin, Shih-Jan; Wilde, Frank; Neuhaus, Michael; Schramm, Alexander; Gellrich, Nils-Claudius; Rana, Majeed

2017-12-01

The benefit of computer-assisted planning in orthognathic surgery has been extensively documented over the last decade. This study aims to evaluate the accuracy of a virtual orthognathic surgical plan by a novel three dimensional (3D) analysis method. Ten patients who required orthognathic surgery were included in this study. A virtual surgical plan was achieved by the combination of a 3D skull model acquired from computed tomography (CT) and surface scanning of the upper and lower dental arch respectively and final occlusal position. Osteotomies and movement of maxilla and mandible were simulated by Dolphin Imaging 11.8 Premium ® (Dolphin Imaging and Management Solutions, Chatsworth, CA). The surgical plan was transferred to surgical splints fabricated by means of Computer Aided Design/Computer Aided Manufacturing (CAD/CAM). Differences of three dimensional measurements between the virtual surgical plan and postoperative results were evaluated. The results from all parameters showed that the virtual surgical plans were successfully transferred by the assistance of CAD/CAM fabricated surgical splint. Wilcoxon's signed rank test showed that no statistically significant deviation between surgical plan and post-operational result could be detected. However, deviation of angle U1 axis-HP and distance of A-CP could not fulfill the clinical success criteria. Virtual surgical planning and CAD/CAM fabricated surgical splint are proven to facilitate treatment planning and offer an accurate surgical result in orthognathic surgery. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Three-dimensional path planning software-assisted transjugular intrahepatic portosystemic shunt: a technical modification.

PubMed

Tsauo, Jiaywei; Luo, Xuefeng; Ye, Linchao; Li, Xiao

2015-06-01

This study was designed to report our results with a modified technique of three-dimensional (3D) path planning software assisted transjugular intrahepatic portosystemic shunt (TIPS). 3D path planning software was recently developed to facilitate TIPS creation by using two carbon dioxide portograms acquired at least 20° apart to generate a 3D path for overlay needle guidance. However, one shortcoming is that puncturing along the overlay would be technically impossible if the angle of the liver access set and the angle of the 3D path are not the same. To solve this problem, a prototype 3D path planning software was fitted with a utility to calculate the angle of the 3D path. Using this, we modified the angle of the liver access set accordingly during the procedure in ten patients. Failure for technical reasons occurred in three patients (unsuccessful wedged hepatic venography in two cases, software technical failure in one case). The procedure was successful in the remaining seven patients, and only one needle pass was required to obtain portal vein access in each case. The course of puncture was comparable to the 3D path in all patients. No procedure-related complication occurred following the procedures. Adjusting the angle of the liver access set to match the angle of the 3D path determined by the software appears to be a favorable modification to the technique of 3D path planning software assisted TIPS.

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.

Three-dimensional computed tomography reconstruction for operative planning in robotic segmentectomy: a pilot study

PubMed Central

Le Moal, Julien; Peillon, Christophe; Dacher, Jean-Nicolas

2018-01-01

Background The objective of our pilot study was to assess if three-dimensional (3D) reconstruction performed by Visible Patient™ could be helpful for the operative planning, efficiency and safety of robot-assisted segmentectomy. Methods Between 2014 and 2015, 3D reconstructions were provided by the Visible Patient™ online service and used for the operative planning of robotic segmentectomy. To obtain 3D reconstruction, the surgeon uploaded the anonymized computed tomography (CT) image of the patient to the secured Visible Patient™ server and then downloaded the model after completion. Results Nine segmentectomies were performed between 2014 and 2015 using a pre-operative 3D model. All 3D reconstructions met our expectations: anatomical accuracy (bronchi, arteries, veins, tumor, and the thoracic wall with intercostal spaces), accurate delimitation of each segment in the lobe of interest, margin resection, free space rotation, portability (smartphone, tablet) and time saving technique. Conclusions We have shown that operative planning by 3D CT using Visible Patient™ reconstruction is useful in our practice of robot-assisted segmentectomy. The main disadvantage is the high cost. Its impact on reducing complications and improving surgical efficiency is the object of an ongoing study. PMID:29600049

Three-dimensional computed tomography reconstruction for operative planning in robotic segmentectomy: a pilot study.

PubMed

Le Moal, Julien; Peillon, Christophe; Dacher, Jean-Nicolas; Baste, Jean-Marc

2018-01-01

The objective of our pilot study was to assess if three-dimensional (3D) reconstruction performed by Visible Patient™ could be helpful for the operative planning, efficiency and safety of robot-assisted segmentectomy. Between 2014 and 2015, 3D reconstructions were provided by the Visible Patient™ online service and used for the operative planning of robotic segmentectomy. To obtain 3D reconstruction, the surgeon uploaded the anonymized computed tomography (CT) image of the patient to the secured Visible Patient™ server and then downloaded the model after completion. Nine segmentectomies were performed between 2014 and 2015 using a pre-operative 3D model. All 3D reconstructions met our expectations: anatomical accuracy (bronchi, arteries, veins, tumor, and the thoracic wall with intercostal spaces), accurate delimitation of each segment in the lobe of interest, margin resection, free space rotation, portability (smartphone, tablet) and time saving technique. We have shown that operative planning by 3D CT using Visible Patient™ reconstruction is useful in our practice of robot-assisted segmentectomy. The main disadvantage is the high cost. Its impact on reducing complications and improving surgical efficiency is the object of an ongoing study.

Evaluation of a stereoscopic camera-based three-dimensional viewing workstation for ophthalmic surgery.

PubMed

Bhadri, Prashant R; Rowley, Adrian P; Khurana, Rahul N; Deboer, Charles M; Kerns, Ralph M; Chong, Lawrence P; Humayun, Mark S

2007-05-01

To evaluate the effectiveness of a prototype stereoscopic camera-based viewing system (Digital Microsurgical Workstation, three-dimensional (3D) Vision Systems, Irvine, California, USA) for anterior and posterior segment ophthalmic surgery. Institutional-based prospective study. Anterior and posterior segment surgeons performed designated standardized tasks on porcine eyes after training on prosthetic plastic eyes. Both anterior and posterior segment surgeons were able to complete tasks requiring minimal or moderate stereoscopic viewing. The results indicate that the system provides improved ergonomics. Improvements in key viewing performance areas would further enhance the value over a conventional operating microscope. The performance of the prototype system is not at par with the planned commercial system. With continued development of this technology, the three- dimensional system may be a novel viewing system in ophthalmic surgery with improved ergonomics with respect to traditional microscopic viewing.

Dependence of energy characteristics of ascending swirling air flow on velocity of vertical blowing

NASA Astrophysics Data System (ADS)

Volkov, R. E.; Obukhov, A. G.; Kutrunov, V. N.

2018-05-01

In the model of a compressible continuous medium, for the complete Navier-Stokes system of equations, an initial boundary problem is proposed that corresponds to the conducted and planned experiments and describes complex three-dimensional flows of a viscous compressible heat-conducting gas in ascending swirling flows that are initiated by a vertical cold blowing. Using parallelization methods, three-dimensional nonstationary flows of a polytropic viscous compressible heat-conducting gas are constructed numerically in different scaled ascending swirling flows under the condition when gravity and Coriolis forces act. With the help of explicit difference schemes and the proposed initial boundary conditions, approximate solutions of the complete system of Navier-Stokes equations are constructed as well as the velocity and energy characteristics of three-dimensional nonstationary gas flows in ascending swirling flows are determined.

Disassembling the clockwork mechanism

NASA Astrophysics Data System (ADS)

Craig, Nathaniel; Garcia Garcia, Isabel; Sutherland, Dave

2017-10-01

The clockwork mechanism is a means of naturally generating exponential hierarchies in theories without significant hierarchies among fundamental parameters. We emphasize the role of interactions in the clockwork mechanism, demonstrating that clockwork is an intrinsically abelian phenomenon precluded in non-abelian theories such as Yang-Mills, non-linear sigma models, and gravity. We also show that clockwork is not realized in extra-dimensional theories through purely geometric effects, but may be generated by appropriate localization of zero modes.

Software for project-based learning of robot motion planning

NASA Astrophysics Data System (ADS)

Moll, Mark; Bordeaux, Janice; Kavraki, Lydia E.

2013-12-01

Motion planning is a core problem in robotics concerned with finding feasible paths for a given robot. Motion planning algorithms perform a search in the high-dimensional continuous space of robot configurations and exemplify many of the core algorithmic concepts of search algorithms and associated data structures. Motion planning algorithms can be explained in a simplified two-dimensional setting, but this masks many of the subtleties and complexities of the underlying problem. We have developed software for project-based learning of motion planning that enables deep learning. The projects that we have developed allow advanced undergraduate students and graduate students to reflect on the performance of existing textbook algorithms and their own variations on such algorithms. Formative assessment has been conducted at three institutions. The core of the software used for this teaching module is also used within the Robot Operating System, a widely adopted platform by the robotics research community. This allows for transfer of knowledge and skills to robotics research projects involving a large variety robot hardware platforms.

76 FR 60777 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-30

... property located at 11701 Mount Holly Road in Charlotte, North Carolina, from the National Priorities List..., maintenance, and five-year reviews, have been completed. However, this deletion does not preclude future..., located at 11701 Mount Holly Road, Charlotte, NC, from the NPL and requests public comment on this...

Habitat classification modelling with incomplete data: Pushing the habitat envelope

Treesearch

Phoebe L. Zarnetske; Thomas C. Edwards; Gretchen G. Moisen

2007-01-01

Habitat classification models (HCMs) are invaluable tools for species conservation, land-use planning, reserve design, and metapopulation assessments, particularly at broad spatial scales. However, species occurrence data are often lacking and typically limited to presence points at broad scales. This lack of absence data precludes the use of many statistical...

76 FR 19784 - Notice of Availability of the Draft Environmental Impact Statement and Draft Resource Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-08

... generation facility capable of generating up to 425 megawatts (MW) of electricity. Up to 170 wind turbines..., eliminating turbines from areas of VRM Class II, precluding construction and maintenance activities during... Amendment to the 1987 Jarbidge Resource Management Plan for the Proposed China Mountain Wind Project AGENCY...

The Conservation of North Carolina's Natural Resources.

ERIC Educational Resources Information Center

Washington City Board of Education, NC.

This is a course designed specifically for use in eastern North Carolina or a similar geographic region but this does not preclude the use of its concepts and basic structure for other geographic regions. Plans and activities are student-centered and many are problem-solving oriented and, therefore, may be modified without disrupting the…

The Virtual Counseling Center: Its Niche, Resources, and Ongoing Research and Development Activity

ERIC Educational Resources Information Center

Horan, John J.

2010-01-01

Thomas Friedman's best sellers have raised awareness of our nation's need to remain competitive in science, technology, engineering, and math (STEM) disciplines. However, advances in these fields cannot occur without the proper cultivation of human potential. The usual costs of career assessment and planning systems preclude their scalability to…

[The clinical advantage of using three dimensional visualization technology in hepatic surgery].

PubMed

Lau, Y Y; Lau, X X

2016-09-01

The three-dimensional body visible system is a further development of the three-dimensional CT reconstruction system. It has a lot of merits over the latter system. Clinical application of the three-dimensional body visible system in liver surgery showed the system to have the following merits: (1) The system can support the Couinaud classification of liver anatomy into two hemilivers, four sectors and eight segments. As the system can rotate the liver to any angle and it has the ability to make part or whole of the liver transparent thus making the internal blood vessels and bile ducts visible. Learning liver anatomy and liver surgery becomes easier. (2)The system can clearly localize liver tumors within the liver segment(s). (3)It can help clinicians to decide and to plan different operations on an individual. (4)By carrying out simulation partial hepatectomy using this system, it can help clinicians to estimate the difficulty and the risks involved in different options of liver resection and finally.(5)The system helps clinicians to identify anomalies in hepatic artery, portal vein, hepatic vein and bile duct, thus making the operation safer. In conclusion, this system significantly improves on the conventional three-dimensional CT reconstruction system. It is especially useful for inexperienced liver surgeons.

A new method to acquire 3-D images of a dental cast

NASA Astrophysics Data System (ADS)

Li, Zhongke; Yi, Yaxing; Zhu, Zhen; Li, Hua; Qin, Yongyuan

2006-01-01

This paper introduced our newly developed method to acquire three-dimensional images of a dental cast. A rotatable table, a laser-knife, a mirror, a CCD camera and a personal computer made up of a three-dimensional data acquiring system. A dental cast is placed on the table; the mirror is installed beside the table; a linear laser is projected to the dental cast; the CCD camera is put up above the dental cast, it can take picture of the dental cast and the shadow in the mirror; while the table rotating, the camera records the shape of the laser streak projected on the dental cast, and transmit the data to the computer. After the table rotated one circuit, the computer processes the data, calculates the three-dimensional coordinates of the dental cast's surface. In data processing procedure, artificial neural networks are enrolled to calibrate the lens distortion, map coordinates form screen coordinate system to world coordinate system. According to the three-dimensional coordinates, the computer reconstructs the stereo image of the dental cast. It is essential for computer-aided diagnosis and treatment planning in orthodontics. In comparison with other systems in service, for example, laser beam three-dimensional scanning system, the characteristic of this three-dimensional data acquiring system: a. celerity, it casts only 1 minute to scan a dental cast; b. compact, the machinery is simple and compact; c. no blind zone, a mirror is introduced ably to reduce blind zone.

The application of Green's theorem to the solution of boundary-value problems in linearized supersonic wing theory

NASA Technical Reports Server (NTRS)

Heaslet, Max A; Lomax, Harvard

1950-01-01

Following the introduction of the linearized partial differential equation for nonsteady three-dimensional compressible flow, general methods of solution are given for the two and three-dimensional steady-state and two-dimensional unsteady-state equations. It is also pointed out that, in the absence of thickness effects, linear theory yields solutions consistent with the assumptions made when applied to lifting-surface problems for swept-back plan forms at sonic speeds. The solutions of the particular equations are determined in all cases by means of Green's theorem, and thus depend on the use of Green's equivalent layer of sources, sinks, and doublets. Improper integrals in the supersonic theory are treated by means of Hadamard's "finite part" technique.

Improved Data Analysis Tools for the Thermal Emission Spectrometer

NASA Astrophysics Data System (ADS)

Rodriguez, K.; Laura, J.; Fergason, R.; Bogle, R.

2017-06-01

We plan to stand up three different database systems for testing of a new datastore for MGS TES data allowing for more accessible tools supporting high throughput data analysis on the high-dimensionality hyperspectral data set.

Investigation and evaluation of a computer program to minimize three-dimensional flight time tracks

NASA Technical Reports Server (NTRS)

Parke, F. I.

1981-01-01

The program for the DC 8-D3 flight planning was slightly modified for the three dimensional flight planning for DC 10 aircrafts. Several test runs of the modified program over the North Atlantic and North America were made for verifying the program. While geopotential height and temperature were used in a previous program as meteorological data, the modified program uses wind direction and speed and temperature received from the National Weather Service. A scanning program was written to collect required weather information from the raw data received in a packed decimal format. Two sets of weather data, the 12-hour forecast and 24-hour forecast based on 0000 GMT, are used for dynamic processes in testruns. In order to save computing time only the weather data of the North Atlantic and North America is previously stored in a PCF file and then scanned one by one.

Multi-scale phenomena of rotation-modified mode-2 internal waves

NASA Astrophysics Data System (ADS)

Deepwell, David; Stastna, Marek; Coutino, Aaron

2018-03-01

We present high-resolution, three-dimensional simulations of rotation-modified mode-2 internal solitary waves at various rotation rates and Schmidt numbers. Rotation is seen to change the internal solitary-like waves observed in the absence of rotation into a leading Kelvin wave followed by Poincaré waves. Mass and energy is found to be advected towards the right-most side wall (for a Northern Hemisphere rotation), leading to increased amplitude of the leading Kelvin wave and the formation of Kelvin-Helmholtz (K-H) instabilities on the upper and lower edges of the deformed pycnocline. These fundamentally three-dimensional instabilities are localized within a region near the side wall and intensify in vigour with increasing rotation rate. Secondary Kelvin waves form further behind the wave from either resonance with radiating Poincaré waves or the remnants of the K-H instability. The first of these mechanisms is in accord with published work on mode-1 Kelvin waves; the second is, to the best of our knowledge, novel to the present study. Both types of secondary Kelvin waves form on the same side of the channel as the leading Kelvin wave. Comparisons of equivalent cases with different Schmidt numbers indicate that while adopting a numerically advantageous low Schmidt number results in the correct general characteristics of the Kelvin waves, excessive diffusion of the pycnocline and various density features precludes accurate representation of both the trailing Poincaré wave field and the intensity and duration of the Kelvin-Helmholtz instabilities.

Measurements of three-dimensional glenoid erosion when planning the prosthetic replacement of osteoarthritic shoulders.

PubMed

Terrier, A; Ston, J; Larrea, X; Farron, A

2014-04-01

The three-dimensional (3D) correction of glenoid erosion is critical to the long-term success of total shoulder replacement (TSR). In order to characterise the 3D morphology of eroded glenoid surfaces, we looked for a set of morphological parameters useful for TSR planning. We defined a scapular coordinates system based on non-eroded bony landmarks. The maximum glenoid version was measured and specified in 3D by its orientation angle. Medialisation was considered relative to the spino-glenoid notch. We analysed regular CT scans of 19 normal (N) and 86 osteoarthritic (OA) scapulae. When the maximum version of OA shoulders was higher than 10°, the orientation was not only posterior, but extended in postero-superior (35%), postero-inferior (6%) and anterior sectors (4%). The medialisation of the glenoid was higher in OA than normal shoulders. The orientation angle of maximum version appeared as a critical parameter to specify the glenoid shape in 3D. It will be very useful in planning the best position for the glenoid in TSR.

Making the Transition to Three-Dimensional Teaching: An NGSS@NSTA Curator and Elementary Science Specialist Shares How to Evaluate Teaching Materials Using the EQuIP Rubric

ERIC Educational Resources Information Center

O'Day, Betsy

2016-01-01

Curriculum and lesson planning require the consideration of many things. With a shift to the "Next Generation Science Standards" ("NGSS"), integrating the dimensions of science and engineering practices, disciplinary core ideas, and crosscutting concepts becomes a focus of that planning. The author, Betsy O'Day, an elementary…

Confounding factors in diagnosing brain death: a case report

PubMed Central

Burns, Jeffrey M; Login, Ivan S

2002-01-01

Background Brain death is strictly defined medically and legally. This diagnosis depends on three cardinal neurological features: coma, absent brainstem reflexes, and apnea. The diagnosis can only be made, however, in the absence of intoxication, hypothermia, or certain medical illnesses. Case presentation A patient with severe hypoxic-ischemic brain injury met the three cardinal neurological features of brain death but concurrent profound hypothyroidism precluded the diagnosis. Our clinical and ethical decisions were further challenged by another facet of this complex case. Although her brain damage indicated a hopeless prognosis, we could not discontinue care based on futility because the only known surrogate was mentally retarded and unable to participate in medical planning. Conclusion The presence of certain medical conditions prohibits a diagnosis of brain death, which is a medicolegal diagnosis of death, not a prediction or forecast of future outcome. While prognostication is important in deciding to withdraw care, it is not a component in diagnosing brain death. PMID:12097152

Endovascular abdominal aortic aneurysm sizing and case planning using the TeraRecon Aquarius workstation.

PubMed

Lee, W Anthony

2007-01-01

The gold standard for preoperative evaluation of an aortic aneurysm is a computed tomography angiogram (CTA). Three-dimensional reconstruction and analysis of the computed tomography data set is enormously helpful, and even sometimes essential, in proper sizing and planning for endovascular stent graft repair. To a large extent, it has obviated the need for conventional angiography for morphologic evaluation. The TeraRecon Aquarius workstation (San Mateo, Calif) represents a highly sophisticated but user-friendly platform utilizing a combination of task-specific hardware and software specifically designed to rapidly manipulate large Digital Imaging and Communications in Medicine (DICOM) data sets and provide surface-shaded and multiplanar renderings in real-time. This article discusses the basics of sizing and planning for endovascular abdominal aortic aneurysm repair and the role of 3-dimensional analysis using the TeraRecon workstation.

Use of 3D reconstruction cloacagrams and 3D printing in cloacal malformations.

PubMed

Ahn, Jennifer J; Shnorhavorian, Margarett; Amies Oelschlager, Anne-Marie E; Ripley, Beth; Shivaram, Giridhar M; Avansino, Jeffrey R; Merguerian, Paul A

2017-08-01

Cloacal anomalies are complex to manage, and the anatomy affects prognosis and management. Assessment historically includes examination under anesthesia, and genitography is often performed, but these do not consistently capture three-dimensional (3D) detail or spatial relationships of the anatomic structures. Three-dimensional reconstruction cloacagrams can provide a high level of detail including channel measurements and the level of the cloaca (<3 cm vs. >3 cm), which typically determines the approach for surgical reconstruction and can impact long-term prognosis. Yet this imaging modality has not yet been directly compared with intra-operative or endoscopic findings. Our objective was to compare 3D reconstruction cloacagrams with endoscopic and intraoperative findings, as well as to describe the use of 3D printing to create models for surgical planning and education. An IRB-approved retrospective review of all cloaca patients seen by our multi-disciplinary program from 2014 to 2016 was performed. All patients underwent examination under anesthesia, endoscopy, 3D reconstruction cloacagram, and subsequent reconstructive surgery at a later date. Patient characteristics, intraoperative details, and measurements from endoscopy and cloacagram were reviewed and compared. One of the 3D cloacagrams was reformatted for 3D printing to create a model for surgical planning. Four patients were included for review, with the Figure illustrating 3D cloacagram results. Measurements of common channel length and urethral length were similar between modalities, particularly with confirming the level of cloaca. No patient experienced any complications or adverse effects from cloacagram or endoscopy. A model was successfully created from cloacagram images with the use of 3D printing technology. Accurate preoperative assessment for cloacal anomalies is important for counseling and surgical planning. Three-dimensional cloacagrams have been shown to yield a high level of anatomic detail. Here, cloacagram measurements are shown to correlate well with endoscopic and intraoperative findings with regards to level of cloaca and Müllerian development. Measurement discrepancies may be due to technical variation indicating a need for further evaluation. The translation of the cloacagram images into a 3D printed model demonstrates potential applications of these models for pre-operative planning and education of both families and trainees. In our series, 3D reconstruction cloacagrams yielded accurate measurements of urethral length and level of cloaca common channel and urethral length, similar to those found on endoscopy. Three-dimensional models can be printed from using cloacagram images, and may be useful for surgical planning and education. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Three-dimensional portable document format: a simple way to present 3-dimensional data in an electronic publication.

PubMed

Danz, Jan C; Katsaros, Christos

2011-08-01

Three-dimensional (3D) models of teeth and soft and hard tissues are tessellated surfaces used for diagnosis, treatment planning, appliance fabrication, outcome evaluation, and research. In scientific publications or communications with colleagues, these 3D data are often reduced to 2-dimensional pictures or need special software for visualization. The portable document format (PDF) offers a simple way to interactively display 3D surface data without additional software other than a recent version of Adobe Reader (Adobe, San Jose, Calif). The purposes of this article were to give an example of how 3D data and their analyses can be interactively displayed in 3 dimensions in electronic publications, and to show how they can be exported from any software for diagnostic reports and communications among colleagues. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Dosimetric Comparison between Three-Dimensional Magnetic Resonance Imaging-Guided and Conventional Two-Dimensional Point A-Based Intracavitary Brachytherapy Planning for Cervical Cancer

PubMed Central

Ren, Juan; Yuan, Wei; Wang, Ruihua; Wang, Qiuping; Li, Yi; Xue, Chaofan; Yan, Yanli; Ma, Xiaowei; Tan, Li; Liu, Zi

2016-01-01

Objective The purpose of this study was to comprehensively compare the 3-dimensional (3D) magnetic resonance imaging (MRI)-guided and conventional 2-dimensional (2D) point A-based intracavitary brachytherapy (BT) planning for cervical cancer with regard to target dose coverage and dosages to adjacent organs-at risk (OARs). Methods A total of 79 patients with cervical cancer were enrolled to receive 2D point A-based BT planning and then immediately to receive 3D planning between October 2011 and April 2013 at the First Hospital Affiliated to Xi’an Jiao Tong University (Xi’an, China). The dose-volume histogram (DVH) parameters for gross tumor volume (GTV), high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV) and OARs were compared between the 2D and 3D planning. Results In small tumors, there was no significant difference in most of the DVHs between 2D and 3D planning (all p>0.05). While in big tumors, 3D BT planning significantly increased the DVHs for most of the GTV, HR-CTV and IR-CTV, and some OARs compared with 2D planning (all P<0.05). In 3D planning, DVHs for GTV, HR-CTV, IR-CTV and some OARs were significantly higher in big tumors than in small tumors (all p<0.05). In contrast, in 2D planning, DVHs for almost all of the HR-CTV and IR-CTV were significantly lower in big tumors (all p<0.05). In eccentric tumors, 3D planning significantly increased dose coverage but decreased dosages to OARs compared with 2D planning (p<0.05). In tumors invading adjacent tissues, the target dose coverage in 3D planning was generally significantly higher than in 2D planning (P<0.05); the dosages to the adjacent rectum and bladder were significantly higher but those to sigmoid colon were lower in 3D planning (all P<0.05). Conclusions 3D MRI image-guided BT planning exhibits advantages over 2D planning in a complex way, generally showing advantages for the treatment of cervical cancer except small tumors. PMID:27611853

A variational dynamic programming approach to robot-path planning with a distance-safety criterion

NASA Technical Reports Server (NTRS)

Suh, Suk-Hwan; Shin, Kang G.

1988-01-01

An approach to robot-path planning is developed by considering both the traveling distance and the safety of the robot. A computationally-efficient algorithm is developed to find a near-optimal path with a weighted distance-safety criterion by using a variational calculus and dynamic programming (VCDP) method. The algorithm is readily applicable to any factory environment by representing the free workspace as channels. A method for deriving these channels is also proposed. Although it is developed mainly for two-dimensional problems, this method can be easily extended to a class of three-dimensional problems. Numerical examples are presented to demonstrate the utility and power of this method.

75 FR 33747 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

... Notice of Intent to Delete the soils of Operable Unit 1 and the underlying ground water of the... preclude future actions under Superfund. This partial deletion pertains to the soils of Operable Unit 1 and... Partial Deletion for the soils of Operable Unit 1 and the underlying ground water of the approximately 8...

77 FR 14717 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

... preclude future actions under Superfund. This partial deletion pertains to the surface soil, unsaturated subsurface soil, surface water and sediments of Operable Unit (OU) 1, the Gateway Lake Ash Study Area, and.... Surface soil, unsaturated subsurface soil, surface water, and sediments at OU-2, OU-3, OU-4, OU-5, OU-6...

Roadless area-intensive management tradeoffs on the Sierra National Forest, California

Treesearch

Robert J. Hrubes; Kent P. Connaughton; Robert W. Sassaman

1979-01-01

This hypothesis was tested by a linear programing model: Roadless areas on the Sierra National Forest precluded from planned future development would be candidates for wilderness designation, and the associated loss in present and future timber harvests could be offset by investing in more intensive management. The results of this simulation test suggest that levels of...

Teaching Coaches to Coach Holistically: Can Problem-Based Learning (PBL) Help?

ERIC Educational Resources Information Center

Jones, Robyn L.; Turner, Poppy

2006-01-01

Background: Coaching, as related to improving others' sporting experience and/or performance, at any level is unquestionably a complex business. General agreement exists that the dynamic and intricate nature of the work in teaching, guiding and managing others in this regard precludes any paint-by-number plans that practitioners can easily follow.…

26 CFR 1.401(a)(26)-1 - Minimum participation requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... other plans for purposes of the average benefit percentage test in section 410(b)(2)(A)(ii). (2....401(a)(26)-5(a) or (b). For this purpose, an employee is not treated as benefiting solely by reason of... precluded from being eligible employees under the arrangement by reason of section 401(k)(4)(B), and (ii...

A CFD Database for Airfoils and Wings at Post-Stall Angles of Attack

NASA Technical Reports Server (NTRS)

Petrilli, Justin; Paul, Ryan; Gopalarathnam, Ashok; Frink, Neal T.

2013-01-01

This paper presents selected results from an ongoing effort to develop an aerodynamic database from Reynolds-Averaged Navier-Stokes (RANS) computational analysis of airfoils and wings at stall and post-stall angles of attack. The data obtained from this effort will be used for validation and refinement of a low-order post-stall prediction method developed at NCSU, and to fill existing gaps in high angle of attack data in the literature. Such data could have potential applications in post-stall flight dynamics, helicopter aerodynamics and wind turbine aerodynamics. An overview of the NASA TetrUSS CFD package used for the RANS computational approach is presented. Detailed results for three airfoils are presented to compare their stall and post-stall behavior. The results for finite wings at stall and post-stall conditions focus on the effects of taper-ratio and sweep angle, with particular attention to whether the sectional flows can be approximated using two-dimensional flow over a stalled airfoil. While this approximation seems reasonable for unswept wings even at post-stall conditions, significant spanwise flow on stalled swept wings preclude the use of two-dimensional data to model sectional flows on swept wings. Thus, further effort is needed in low-order aerodynamic modeling of swept wings at stalled conditions.

Three-Dimensional Path Planning Software-Assisted Transjugular Intrahepatic Portosystemic Shunt: A Technical Modification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsauo, Jiaywei, E-mail: 80732059@qq.com; Luo, Xuefeng, E-mail: luobo-913@126.com; Ye, Linchao, E-mail: linchao.ye@siemens.com

2015-06-15

PurposeThis study was designed to report our results with a modified technique of three-dimensional (3D) path planning software assisted transjugular intrahepatic portosystemic shunt (TIPS).Methods3D path planning software was recently developed to facilitate TIPS creation by using two carbon dioxide portograms acquired at least 20° apart to generate a 3D path for overlay needle guidance. However, one shortcoming is that puncturing along the overlay would be technically impossible if the angle of the liver access set and the angle of the 3D path are not the same. To solve this problem, a prototype 3D path planning software was fitted with a utility to calculate themore » angle of the 3D path. Using this, we modified the angle of the liver access set accordingly during the procedure in ten patients.ResultsFailure for technical reasons occurred in three patients (unsuccessful wedged hepatic venography in two cases, software technical failure in one case). The procedure was successful in the remaining seven patients, and only one needle pass was required to obtain portal vein access in each case. The course of puncture was comparable to the 3D path in all patients. No procedure-related complication occurred following the procedures.ConclusionsAdjusting the angle of the liver access set to match the angle of the 3D path determined by the software appears to be a favorable modification to the technique of 3D path planning software assisted TIPS.« less

Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

NASA Astrophysics Data System (ADS)

Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

2010-08-01

In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

Echocardiography derived three-dimensional printing of normal and abnormal mitral annuli.

PubMed

Mahmood, Feroze; Owais, Khurram; Montealegre-Gallegos, Mario; Matyal, Robina; Panzica, Peter; Maslow, Andrew; Khabbaz, Kamal R

2014-01-01

The objective of this study was to assess the clinical feasibility of using echocardiographic data to generate three-dimensional models of normal and pathologic mitral valve annuli before and after repair procedures. High-resolution transesophageal echocardiographic data from five patients was analyzed to delineate and track the mitral annulus (MA) using Tom Tec Image-Arena software. Coordinates representing the annulus were imported into Solidworks software for constructing solid models. These solid models were converted to stereolithographic (STL) file format and three-dimensionally printed by a commercially available Maker Bot Replicator 2 three-dimensional printer. Total time from image acquisition to printing was approximately 30 min. Models created were highly reflective of known geometry, shape and size of normal and pathologic mitral annuli. Post-repair models also closely resembled shapes of the rings they were implanted with. Compared to echocardiographic images of annuli seen on a computer screen, physical models were able to convey clinical information more comprehensively, making them helpful in appreciating pathology, as well as post-repair changes. Three-dimensional printing of the MA is possible and clinically feasible using routinely obtained echocardiographic images. Given the short turn-around time and the lack of need for additional imaging, a technique we describe here has the potential for rapid integration into clinical practice to assist with surgical education, planning and decision-making.

Combining transrectal ultrasound and CT for image-guided adaptive brachytherapy of cervical cancer: Proof of concept.

PubMed

Nesvacil, Nicole; Schmid, Maximilian P; Pötter, Richard; Kronreif, Gernot; Kirisits, Christian

To investigate the feasibility of a treatment planning workflow for three-dimensional image-guided cervix cancer brachytherapy, combining volumetric transrectal ultrasound (TRUS) for target definition with CT for dose optimization to organs at risk (OARs), for settings with no access to MRI. A workflow for TRUS/CT-based volumetric treatment planning was developed, based on a customized system including ultrasound probe, stepper unit, and software for image volume acquisition. A full TRUS/CT-based workflow was simulated in a clinical case and compared with MR- or CT-only delineation. High-risk clinical target volume was delineated on TRUS, and OARs were delineated on CT. Manually defined tandem/ring applicator positions on TRUS and CT were used as a reference for rigid registration of the image volumes. Treatment plan optimization for TRUS target and CT organ volumes was performed and compared to MRI and CT target contours. TRUS/CT-based contouring, applicator reconstruction, image fusion, and treatment planning were feasible, and the full workflow could be successfully demonstrated. The TRUS/CT plan fulfilled all clinical planning aims. Dose-volume histogram evaluation of the TRUS/CT-optimized plan (high-risk clinical target volume D 90 , OARs D 2cm³ for) on different image modalities showed good agreement between dose values reported for TRUS/CT and MRI-only reference contours and large deviations for CT-only target parameters. A TRUS/CT-based workflow for full three-dimensional image-guided cervix brachytherapy treatment planning seems feasible and may be clinically comparable to MRI-based treatment planning. Further development to solve challenges with applicator definition in the TRUS volume is required before systematic applicability of this workflow. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Three-dimensional modeling of flexible pavements : research implementation plan.

DOT National Transportation Integrated Search

2006-02-14

Many of the asphalt pavement analysis programs are based on linear elastic models. A linear viscoelastic models : would be superior to linear elastic models for analyzing the response of asphalt concrete pavements to loads. There : is a need to devel...

Patient-specific distal radius locking plate for fixation and accurate 3D positioning in corrective osteotomy.

PubMed

Dobbe, J G G; Vroemen, J C; Strackee, S D; Streekstra, G J

2014-11-01

Preoperative three-dimensional planning methods have been described extensively. However, transferring the virtual plan to the patient is often challenging. In this report, we describe the management of a severely malunited distal radius fracture using a patient-specific plate for accurate spatial positioning and fixation. Twenty months postoperatively the patient shows almost painless reconstruction and a nearly normal range of motion.

Cosmetic sequelae after oncoplastic surgery of the breast. Classification and factors for prevention.

PubMed

Acea Nebril, Benigno; Cereijo Garea, Carmen; García Novoa, Alejandra

2015-02-01

Oncoplastic surgery is an essential tool in the surgical approach to women with breast cancer. These techniques are not absolute guarantee for a good cosmetic result and therefore some patients will have cosmetic sequelae secondary to poor surgical planning, the effects of adjuvant treatments or the need for resection greater than originally planned. The high frequency of these cosmetic sequelae in oncology practice makes it necessary to classify them for optimal surgical planning. The aim of this paper is to present a classification of cosmetic sequelae after oncoplastic procedures to identify those factors that are crucial to its prevention. This classification contains 4 groups: breast contour deformities, asymmetries, alterations in nipple-aréola complex (NAC) and defects in the three dimensional structure of the breast. A significant group of these sequelae (asymmetries and deformities) are associated with breast irradiation and need an accurate information process with patients to set realistic expectations about cosmetic results. Finally, there is another group of sequelae (NAC disorders and three-dimensional structure) that are related to poor planning and deficiencies in surgical approach, therfore specific training is essential for learning these surgical techniques. Copyright © 2014 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Integrating three-dimensional digital technologies for comprehensive implant dentistry.

PubMed

Patel, Neal

2010-06-01

The increase in the popularity of and the demand for the use of dental implants to replace teeth has encouraged advancement in clinical technology and materials to improve patients' acceptance and clinical outcomes. Recent advances such as three-dimensional dental radiography with cone-beam computed tomography (CBCT), precision dental implant planning software and clinical execution with guided surgery all play a role in the success of implant dentistry. The author illustrates the technique of comprehensive implant dentistry planning through integration of computer-aided design/computer-aided manufacturing (CAD/CAM) and CBCT data. The technique includes clinical treatment with guided surgery, including the creation of a final restoration with a high-strength ceramic (IPS e.max CAD, Ivoclar Vivadent, Amherst, N.Y.). The author also introduces a technique involving CAD/CAM for fabricating custom implant abutments. The release of software integrating CEREC Acquisition Center with Bluecam (Sirona Dental Systems, Charlotte, N.C.) chairside CAD/CAM and Galileos CBCT imaging (Sirona Dental Systems) allows dentists to plan implant placement, perform implant dentistry with increased precision and provide predictable restorative results by using chairside IPS e.max CAD. The precision of clinical treatment provided by the integration of CAD/CAM and CBCT allows dentists to plan for ideal surgical placement and the appropriate thickness of restorative modalities before placing implants.

[3D planning in maxillofacial surgery].

PubMed

Hoarau, R; Zweifel, D; Lanthemann, E; Zrounba, H; Broome, M

2014-10-01

The development of new technologies such as three-dimensional (3D) planning has changed the everyday practice in maxillofacial surgery. Rapid prototyping associated with the 3D planning has also enabled the creation of patient specific surgical tools, such as cutting guides. As with all new technologies, uses, practicalities, cost effectiveness and especially benefits for the patients have to be carefully evaluated. In this paper, several examples of 3D planning that have been used in our institution are presented. The advantages such as the accuracy of the reconstructive surgery and decreased operating time, as well as the difficulties have also been addressed.

A Cost-Effective, In-House, Positioning and Cutting Guide System for Orthognathic Surgery.

PubMed

McAllister, Peter; Watson, Melanie; Burke, Ezra

2018-03-01

Technological advances in 3D printing can dramatically improve orthognathic surgical planning workflow. Custom positioning and cutting guides enable intraoperative reproduction of pre-planned osteotomy cuts and can result in greater surgical accuracy and patient safety. This short paper describes the use of freeware (some with open-source) combined with in-house 3D printing facilities to produce reliable, affordable osteotomy cutting guides. Open-source software (3D Slicer) is used to visualise and segment three-dimensional planning models from imported conventional computed tomography (CT) scans. Freeware (Autodesk Meshmixer ©) allows digital manipulation of maxillary and mandibular components to plan precise osteotomy cuts. Bespoke cutting guides allow exact intraoperative positioning. These are printed in polylactic acid (PLA) using a fused-filament fabrication 3D printer. Fixation of the osteotomised segments is achieved using plating templates and four pre-adapted plates with planned screw holes over the thickest bone. We print maxilla/ mandible models with desired movements incorporated to use as a plating template. A 3D printer capable of reproducing a complete skull can be procured for £1000, with material costs in the region of £10 per case. Our production of models and guides typically takes less than 24 hours of total print time. The entire production process is frequently less than three days. Externally sourced models and guides cost significantly more, frequently encountering costs totalling £1500-£2000 for models and guides for a bimaxillary osteotomy. Three-dimensional guided surgical planning utilising custom cutting guides enables the surgeon to determine optimal orientation of osteotomy cuts and better predict the skeletal maxilla/mandible relationship following surgery. The learning curve to develop proficiency using planning software and printer settings is offset by increased surgical predictability and reduced theatre time, making this form of planning a worthy investment.

Three-dimensional photogrammetry for surgical planning of tissue expansion in hemifacial microsomia.

PubMed

Jayaratne, Yasas S N; Lo, John; Zwahlen, Roger A; Cheung, Lim K

2010-12-01

We aim to illustrate the applications of 3-dimensional (3-D) photogrammetry for surgical planning and longitudinal assessment of the volumetric changes in hemifacial microsomia. A 3-D photogrammetric system was employed for planning soft tissue expansion and transplantation of a vascularized scapular flap for a patient with hemifacial microsomia. The facial deficiency was calculated by superimposing a mirror of the normal side on the preoperative image. Postsurgical volumetric changes were monitored by serial superimposition of 3-D images. A total of 31 cm(3) of tissue expansion was achieved within a period of 4 weeks. A scapular free flap measuring 8 cm × 5 cm was transplanted to augment the facial deficiency. Postsurgical shrinkage of the flap was observed mainly in the first 3 months and it was minimal thereafter. 3-D photogrammetry can be used as a noninvasive objective tool for assessing facial deformity, planning, and postoperative follow-up of surgical correction of facial asymmetry.

Performance evaluation of an improved optical computed tomography polymer gel dosimeter system for 3D dose verification of static and dynamic phantom deliveries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopatiuk-Tirpak, O.; Langen, K. M.; Meeks, S. L.

2008-09-15

The performance of a next-generation optical computed tomography scanner (OCTOPUS-5X) is characterized in the context of three-dimensional gel dosimetry. Large-volume (2.2 L), muscle-equivalent, radiation-sensitive polymer gel dosimeters (BANG-3) were used. Improvements in scanner design leading to shorter acquisition times are discussed. The spatial resolution, detectable absorbance range, and reproducibility are assessed. An efficient method for calibrating gel dosimeters using the depth-dose relationship is applied, with photon- and electron-based deliveries yielding equivalent results. A procedure involving a preirradiation scan was used to reduce the edge artifacts in reconstructed images, thereby increasing the useful cross-sectional area of the dosimeter by nearly amore » factor of 2. Dose distributions derived from optical density measurements using the calibration coefficient show good agreement with the treatment planning system simulations and radiographic film measurements. The feasibility of use for motion (four-dimensional) dosimetry is demonstrated on an example comparing dose distributions from static and dynamic delivery of a single-field photon plan. The capability to visualize three-dimensional dose distributions is also illustrated.« less

The application of 3-dimensional printing for preoperative planning in oral and maxillofacial surgery in dogs and cats.

PubMed

Winer, Jenna N; Verstraete, Frank J M; Cissell, Derek D; Lucero, Steven; Athanasiou, Kyriacos A; Arzi, Boaz

2017-10-01

To describe the application of 3-dimensional (3D) printing in advanced oral and maxillofacial surgery (OMFS) and to discuss the benefits of this modality in surgical planning, student and resident training, and client education. Retrospective case series. Client-owned dogs (n = 28) and cats (n = 4) with 3D printing models of the skulls. The medical records of 32 cases with 3D printing prior to major OMFS were reviewed. Indications for 3D printing included preoperative planning for mandibular reconstruction after mandibulectomy (n = 12 dogs) or defect nonunion fracture (n = 6 dogs, 2 cats), mapping of ostectomy location for temporomandibular joint ankylosis or pseudoankylosis (n = 4 dogs), assessment of palatal defects (n = 2 dogs, 1 cat), improved understanding of complex anatomy in cases of neoplasia located in challenging locations (n = 2 dogs, 1 cat), and in cases of altered anatomy secondary to trauma (n = 2 dogs). In the authors' experience, 3D printed models serve as excellent tools for OMFS planning and resident training. Furthermore, 3D printed models are a valuable resource to improve clients' understanding of the pet's disorder and the recommended treatment. Three-dimensional printed models should be considered viable tools for surgical planning, resident training, and client education in candidates for complex OMFS. © 2017 The American College of Veterinary Surgeons.

Treatment planning for internal emitter therapy: Methods, applications and clinical implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sgouros, G.

1999-01-01

Treatment planning involves three basic steps: (1) a procedure must be devised that will provide the most relevant information, (2) the procedure must be applied and (3) the resulting information must be translated into a definition of the optimum implementation. There are varying degrees of treatment planning that may be implemented in internal emitter therapy. As in chemotherapy, the information from a Phase 1 study may be used to treat patients based upon body surface area. If treatment planning is included on a patient-specific basis, a pretherapy, trace-labeled, administration of the radiopharmaceutical is generally required. The data collected following themore » tracer dose may range from time-activity curves of blood and whole-body for use in blood, marrow or total body absorbed dose estimation to patient imaging for three-dimensional internal emitter dosimetry. The most ambitious approach requires a three-dimensional set of images representing radionuclide distribution (SPECT or PET) and a corresponding set of images representing anatomy (CT or MRI). The absorbed dose (or dose-rate) distribution may be obtained by convolution of a point kernel with the radioactivity distribution or by direct Monte Carlo calculation. A critical requirement for both techniques is the development of an overall structure that makes it possible, in a routine manner, to input the images, to identify the structures of interest and to display the results of the dose calculations in a clinically relevant manner. 52 refs., 4 figs., 1 tab.« less

Numerical solutions for heat flow in adhesive lap joints

NASA Technical Reports Server (NTRS)

Howell, P. A.; Winfree, William P.

1992-01-01

The present formulation for the modeling of heat transfer in thin, adhesively bonded lap joints precludes difficulties associated with large aspect ratio grids required by standard FEM formulations. This quasi-static formulation also reduces the problem dimensionality (by one), thereby minimizing computational requirements. The solutions obtained are found to be in good agreement with both analytical solutions and solutions from standard FEM programs. The approach is noted to yield a more accurate representation of heat-flux changes between layers due to a disbond.

[Significance of three-dimensional reconstruction as a method of preoperative planning of laparoscopic radiofrequency ablation].

PubMed

Zhang, W W; Wang, H G; Shi, X J; Chen, M Y; Lu, S C

2016-09-01

To discuss the significance of three-dimensional reconstruction as a method of preoperative planning of laparoscopic radiofrequency ablation(LRFA). Thirty-two cases of LRFA admitted from January 2014 to December 2015 in Department of Hepatobiliary Surgery, Chinese People's Liberation Army General Hospital were analyzed(3D-LRFA group). Three-dimensional(3D) reconstruction were taken as a method of preoperative planning in 3D-LRFA group.Other 64 LRFA cases were paired over the same period without three-dimensional reconstruction before the operation (LRFA group). Hepatobiliary system contrast enhanced CT scan of 3D-RFA patients were taken by multi-slice spiral computed tomography(MSCT), and the DICOM data were processed by IQQA(®)-Liver and IQQA(®)-guide to make 3D reconstruction.Using 3D reconstruction model, diameter and scope of tumor were measured, suitable size (length and radiofrequency length) and number of RFA electrode were chosen, scope and effect of radiofrequency were simulated, reasonable needle track(s) was planed, position and angle of laparoscopic ultrasound (LUS) probe was designed and LUS image was simulated.Data of operation and recovery were collected and analyzed. Data between two sets of measurement data were compared with t test or rank sum test, and count data with χ(2) test or Fisher exact probability test.Tumor recurrence rate was analyzed with the Kaplan-Meier survival curve and Log-rank (Mantel-Cox) test. Compared with LRFA group ((216.8±66.2) minutes, (389.1±183.4) s), 3D-LRFA group ((173.3±59.4) minutes, (242.2±90.8) s) has shorter operation time(t=-3.138, P=0.002) and shorter mean puncture time(t=-2.340, P=0.021). There was no significant difference of blood loss(P=0.170), ablation rate (P=0.871) and incidence of complications(P=1.000). Compared with LRFA group ((6.3±3.9)days, (330±102)U/L, (167±64)ng/L), 3D-LRFA group ((4.3±3.1) days, (285±102) U/L, (139±43) ng/L) had shorter post-operative stay(t=-2.527, P=0.016), less post-operation ALT changes (t=-2.038, P=0.048) and post-operative TNF-α changes(t=-2.233, P=0.027). Disease-free survival between two groups was significantly different (χ(2)=4.049, P=0.046). Disease-free survival of 12 months survival rates were 77.6% and 65.7% in 3D-LRFA group and LRFA group, respectively.The median disease-free survival was 16.0 months in LRFA group and over 24.0 months in 3D-LRFA group. Three-dimensional model of liver reconstruction based on image information is a powerful tool in liver surgery planning.It helps to simulate tumor location and vital tubular structure, make plan for interventional treatment, and therefore mean puncture time and operation time is shortened, influence on liver function is reduced, hospital stay is decreased and DFS is prolonged.

Three-dimensional pulmonary model using rapid-prototyping in patient with lung cancer requiring segmentectomy.

PubMed

Akiba, Tadashi; Nakada, Takeo; Inagaki, Takuya

2014-01-01

Thoracoscopic pulmonary segmentectomy of the lung is sometime adopted for the lung cancer, but a problem with segmentectomy is variable anatomy. Recently, we are exploring the impact of three-dimensional models using rapid-prototyping technique. It is useful for decision making, surgical planning, and intraoperative orientation for surgical treatment in patient with lung cancer who underwent pulmonary segmentectomy. These newly created models allow us to clearly identify the surgical margin and the intersegmental plane, vessels, and bronchi related to the cancer in the posterior segment. To the best of our knowledge, there are few reports describing a pulmonary model so far.

Virtual reality in urban water management: communicating urban flooding with particle-based CFD simulations.

PubMed

Winkler, Daniel; Zischg, Jonatan; Rauch, Wolfgang

2018-01-01

For communicating urban flood risk to authorities and the public, a realistic three-dimensional visual display is frequently more suitable than detailed flood maps. Virtual reality could also serve to plan short-term flooding interventions. We introduce here an alternative approach for simulating three-dimensional flooding dynamics in large- and small-scale urban scenes by reaching out to computer graphics. This approach, denoted 'particle in cell', is a particle-based CFD method that is used to predict physically plausible results instead of accurate flow dynamics. We exemplify the approach for the real flooding event in July 2016 in Innsbruck.

26 CFR 1.79-4T - Questions and answers relating to the nondiscrimination requirements for group-term life...

Code of Federal Regulations, 2011 CFR

2011-04-01

... insurer. For example, where an employer has both health insurance coverage and a plan of group-term life... life insurance must include the excess, if any, of the payments the employer makes for the health... that precludes individual selection. The mere fact that a life insurance policy is nondiscriminatory is...

26 CFR 1.79-4T - Questions and answers relating to the nondiscrimination requirements for group-term life...

Code of Federal Regulations, 2010 CFR

2010-04-01

... insurer. For example, where an employer has both health insurance coverage and a plan of group-term life... life insurance must include the excess, if any, of the payments the employer makes for the health... that precludes individual selection. The mere fact that a life insurance policy is nondiscriminatory is...

Prediction of Pathologic Fracture Risk in Activities of Daily Living and Rehabilitation of Patients With Metastatic Breast Carcinoma of the Pelvis and Femur

DTIC Science & Technology

2002-08-01

demonstrated in three-dimensional graphics and animations. This computer model will aid in planning of non-operative or operative management, rehabilitation regimens, nursing programs, and patient education .

Plastic and Large-Deflection Analysis of Nonlinear Structures

NASA Technical Reports Server (NTRS)

Thomson, R. G.; Hayduk, R. J.; Robinson, M. P.; Durling, B. J.; Pifko, A.; Levine, H. S.; Armen, H. J.; Levy, A.; Ogilvie, P.

1982-01-01

Plastic and Large Deflection Analysis of Nonlinear Structures (PLANS) system is collection of five computer programs for finite-element static-plastic and large deflection analysis of variety of nonlinear structures. System considers bending and membrane stresses, general three-dimensional bodies, and laminated composites.

Inducible fluorescent speckle microscopy

PubMed Central

Aguiar, Paulo; Belsley, Michael; Maiato, Helder

2016-01-01

The understanding of cytoskeleton dynamics has benefited from the capacity to generate fluorescent fiducial marks on cytoskeleton components. Here we show that light-induced imprinting of three-dimensional (3D) fluorescent speckles significantly improves speckle signal and contrast relative to classic (random) fluorescent speckle microscopy. We predict theoretically that speckle imprinting using photobleaching is optimal when the laser energy and fluorophore responsivity are related by the golden ratio. This relation, which we confirm experimentally, translates into a 40% remaining signal after speckle imprinting and provides a rule of thumb in selecting the laser power required to optimally prepare the sample for imaging. This inducible speckle imaging (ISI) technique allows 3D speckle microscopy to be performed in readily available libraries of cell lines or primary tissues expressing fluorescent proteins and does not preclude conventional imaging before speckle imaging. As a proof of concept, we use ISI to measure metaphase spindle microtubule poleward flux in primary cells and explore a scaling relation connecting microtubule flux to metaphase duration. PMID:26783303

Inducible fluorescent speckle microscopy.

PubMed

Pereira, António J; Aguiar, Paulo; Belsley, Michael; Maiato, Helder

2016-01-18

The understanding of cytoskeleton dynamics has benefited from the capacity to generate fluorescent fiducial marks on cytoskeleton components. Here we show that light-induced imprinting of three-dimensional (3D) fluorescent speckles significantly improves speckle signal and contrast relative to classic (random) fluorescent speckle microscopy. We predict theoretically that speckle imprinting using photobleaching is optimal when the laser energy and fluorophore responsivity are related by the golden ratio. This relation, which we confirm experimentally, translates into a 40% remaining signal after speckle imprinting and provides a rule of thumb in selecting the laser power required to optimally prepare the sample for imaging. This inducible speckle imaging (ISI) technique allows 3D speckle microscopy to be performed in readily available libraries of cell lines or primary tissues expressing fluorescent proteins and does not preclude conventional imaging before speckle imaging. As a proof of concept, we use ISI to measure metaphase spindle microtubule poleward flux in primary cells and explore a scaling relation connecting microtubule flux to metaphase duration. © 2016 Pereira et al.

Evaluation of the Revolver Ignition Design at the National Ignition Facility Using Polar-Direct-Drive Illumination

NASA Astrophysics Data System (ADS)

McKenty, P. W.; Collins, T. J. B.; Marozas, J. A.; Campbell, E. M.; Molvig, K.; Schmitt, M.

2017-10-01

The direct-drive ignition design Revolver employs a triple-shell target using a beryllium ablator, a copper driver, and an eventual gold pusher. Symmetric numerical calculations indicate that each of the three shells exhibit low convergence ( 3to 5) resulting in a modest gain (G 4) for 1.7 MJ of incident laser energy. Studies are now underway to evaluate the robustness of this design employing polar direct drive (PDD) at the National Ignition Facility. Integral to these calculations is the leveraging of illumination conditioning afforded by research done to demonstrate ignition for a traditional PDD hot-spot target design. Two-dimensional simulation results, employing nonlocal electron-thermal transport and cross-beam energy transport, will be presented that indicate ignition using PDD. A study of the allowed levels of long-wavelength perturbations (target offset and power imbalance) not precluding ignition will also be examined. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Fast, axis-agnostic, dynamically summarized storage and retrieval for mass spectrometry data.

PubMed

Handy, Kyle; Rosen, Jebediah; Gillan, André; Smith, Rob

2017-01-01

Mass spectrometry, a popular technique for elucidating the molecular contents of experimental samples, creates data sets comprised of millions of three-dimensional (m/z, retention time, intensity) data points that correspond to the types and quantities of analyzed molecules. Open and commercial MS data formats are arranged by retention time, creating latency when accessing data across multiple m/z. Existing MS storage and retrieval methods have been developed to overcome the limitations of retention time-based data formats, but do not provide certain features such as dynamic summarization and storage and retrieval of point meta-data (such as signal cluster membership), precluding efficient viewing applications and certain data-processing approaches. This manuscript describes MzTree, a spatial database designed to provide real-time storage and retrieval of dynamically summarized standard and augmented MS data with fast performance in both m/z and RT directions. Performance is reported on real data with comparisons against related published retrieval systems.

Three dimensional image correlation of CT, MR, and PET studies in radiotherapy treatment planning of brain tumors.

PubMed

Schad, L R; Boesecke, R; Schlegel, W; Hartmann, G H; Sturm, V; Strauss, L G; Lorenz, W J

1987-01-01

A treatment planning system for stereotactic convergent beam irradiation of deeply localized brain tumors is reported. The treatment technique consists of several moving field irradiations in noncoplanar planes at a linear accelerator facility. Using collimated narrow beams, a high concentration of dose within small volumes with a dose gradient of 10-15%/mm was obtained. The dose calculation was based on geometrical information of multiplanar CT or magnetic resonance (MR) imaging data. The patient's head was fixed in a stereotactic localization system, which is usable at CT, MR, and positron emission tomography (PET) installations. Special computer programs for correction of the geometrical MR distortions allowed a precise correlation of the different imaging modalities. The therapist can use combinations of CT, MR, and PET data for defining target volume. For instance, the superior soft tissue contrast of MR coupled with the metabolic features of PET may be a useful addition in the radiation treatment planning process. Furthermore, other features such as calculated dose distribution to critical structures can also be transferred from one set of imaging data to another and can be displayed as three-dimensional shaded structures.

Principles of three-dimensional printing and clinical applications within the abdomen and pelvis.

PubMed

Bastawrous, Sarah; Wake, Nicole; Levin, Dmitry; Ripley, Beth

2018-04-04

Improvements in technology and reduction in costs have led to widespread interest in three-dimensional (3D) printing. 3D-printed anatomical models contribute to personalized medicine, surgical planning, and education across medical specialties, and these models are rapidly changing the landscape of clinical practice. A physical object that can be held in one's hands allows for significant advantages over standard two-dimensional (2D) or even 3D computer-based virtual models. Radiologists have the potential to play a significant role as consultants and educators across all specialties by providing 3D-printed models that enhance clinical care. This article reviews the basics of 3D printing, including how models are created from imaging data, clinical applications of 3D printing within the abdomen and pelvis, implications for education and training, limitations, and future directions.

SU-F-J-57: Effectiveness of Daily CT-Based Three-Dimensional Image Guided and Adaptive Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moriya, S; National Cancer Center, Kashiwa, Chiba; Tachibana, H

Purpose: Daily CT-based three-dimensional image-guided and adaptive (CTIGRT-ART) proton therapy system was designed and developed. We also evaluated the effectiveness of the CTIGRT-ART. Methods: Retrospective analysis was performed in three lung cancer patients: Proton treatment planning was performed using CT image datasets acquired by Toshiba Aquilion ONE. Planning target volume and surrounding organs were contoured by a well-trained radiation oncologist. Dose distribution was optimized using 180-deg. and 270-deg. two fields in passive scattering proton therapy. Well commissioned Simplified Monte Carlo algorithm was used as dose calculation engine. Daily consecutive CT image datasets was acquired by an in-room CT (Toshiba Aquilionmore » LB). In our in-house program, two image registrations for bone and tumor were performed to shift the isocenter using treatment CT image dataset. Subsequently, dose recalculation was performed after the shift of the isocenter. When the dose distribution after the tumor registration exhibits change of dosimetric parameter of CTV D90% compared to the initial plan, an additional process of was performed that the range shifter thickness was optimized. Dose distribution with CTV D90% for the bone registration, the tumor registration only and adaptive plan with the tumor registration was compared to the initial plan. Results: In the bone registration, tumor dose coverage was decreased by 16% on average (Maximum: 56%). The tumor registration shows better coverage than the bone registration, however the coverage was also decreased by 9% (Maximum: 22%) The adaptive plan shows similar dose coverage of the tumor (Average: 2%, Maximum: 7%). Conclusion: There is a high possibility that only image registration for bone and tumor may reduce tumor coverage. Thus, our proposed methodology of image guidance and adaptive planning using the range adaptation after tumor registration would be effective for proton therapy. This research is partially supported by Japan Agency for Medical Research and Development (AMED).« less

Tense Times and Language Planning

ERIC Educational Resources Information Center

Bianco, Joseph Lo

2008-01-01

This article discusses the different effects arising from deliberations on language policy in conferences dominated by professionals compared with the interests, priorities and demands of geo-political and military security coming from defense interests. The paper proposes a three dimensional way to understand language policy: text, discourse and…

Three-dimensional esthetic analysis in treatment planning for implant-supported fixed prosthesis in the edentulous maxilla: review of the esthetics literature.

PubMed

Bidra, Avinash S

2011-08-01

Fixed implant-supported prosthesis for the edentulous maxilla has gained tremendous popularity over the years. Multiple prosthetic designs have been introduced in order to accommodate a gamut of clinical situations. Irrespective of the design, it is paramount that the esthetics imparted by the prosthesis be uncompromised. Though esthetics is subjective, a common ground exists where all its fundamental principles converge. This article reviews pertinent dental and facial esthetics literature for application of various esthetic concepts involved in diagnosis and treatment planning for an implant-supported fixed prosthesis in the edentulous maxilla. Three-dimensional esthetic analysis involves assessment of various esthetic parameters in superior-inferior, medial-lateral, and anterior-posterior dimensions. The impact of various esthetic parameters such as facial forms, facial profiles, maxillary teeth positions, maxillary teeth proportions, smile lines, lip support, gingival display, facial midline, dental midline, horizontal cant, and smile width are discussed in detail. © 2011 Wiley Periodicals, Inc.

Numerical optimization of three-dimensional coils for NSTX-U

DOE PAGES

Lazerson, S. A.; Park, J. -K.; Logan, N.; ...

2015-09-03

A tool for the calculation of optimal three-dimensional (3D) perturbative magnetic fields in tokamaks has been developed. The IPECOPT code builds upon the stellarator optimization code STELLOPT to allow for optimization of linear ideal magnetohydrodynamic perturbed equilibrium (IPEC). This tool has been applied to NSTX-U equilibria, addressing which fields are the most effective at driving NTV torques. The NTV torque calculation is performed by the PENT code. Optimization of the normal field spectrum shows that fields with n = 1 character can drive a large core torque. It is also shown that fields with n = 3 features are capablemore » of driving edge torque and some core torque. Coil current optimization (using the planned in-vessel and existing RWM coils) on NSTX-U suggest the planned coils set is adequate for core and edge torque control. In conclusion, comparison between error field correction experiments on DIII-D and the optimizer show good agreement.« less

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. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Automated flight path planning for virtual endoscopy.

PubMed

Paik, D S; Beaulieu, C F; Jeffrey, R B; Rubin, G D; Napel, S

1998-05-01

In this paper, a novel technique for rapid and automatic computation of flight paths for guiding virtual endoscopic exploration of three-dimensional medical images is described. While manually planning flight paths is a tedious and time consuming task, our algorithm is automated and fast. Our method for positioning the virtual camera is based on the medial axis transform but is much more computationally efficient. By iteratively correcting a path toward the medial axis, the necessity of evaluating simple point criteria during morphological thinning is eliminated. The virtual camera is also oriented in a stable viewing direction, avoiding sudden twists and turns. We tested our algorithm on volumetric data sets of eight colons, one aorta and one bronchial tree. The algorithm computed the flight paths in several minutes per volume on an inexpensive workstation with minimal computation time added for multiple paths through branching structures (10%-13% per extra path). The results of our algorithm are smooth, centralized paths that aid in the task of navigation in virtual endoscopic exploration of three-dimensional medical images.

Three-Dimensional Imaging and Quantification of Biomass and Biofilms in Porous Media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorthe Wildenschild

2012-10-10

A new method to resolve biofilms in three dimensions in porous media using high-resolution synchrotron-based x-ray computed microtomography (CMT) has been developed. Imaging biofilms in porous media without disturbing the natural spatial arrangement of the porous media and associated biofilm has been a challenging task, primarily because porous media generally precludes conventional imaging via optical microscopy; x-ray tomography offers a potential alternative. One challenge for using this method is that most conventional x-ray contrast agents are water-soluble and easily diffuse into biofilms. To overcome this problem, silver-coated microspheres were added to the fluid phase to create an x-ray contrast thatmore » does not diffuse into the biofilm mass. Using this approach, biofilm imaging in porous media was accomplished with sufficient contrast to differentiate between the biomass- and fluid-filled pore spaces. The method was validated by using a two-dimensional micro-model flow cell where both light microscopy and CMT imaging were used to im age the biofilm. The results of this work has been published in Water Resources Research (Iltis et al., 2010). Additional work needs to be done to optimize this imaging approach, specifically, we find that the quality of the images are highly dependent on the coverage of the biofilm with Ag particles, - which means that we may have issues in dead-end pore space and for very low density (fluffy) biofilms. What we can image for certain with this technique is the biofilm surface that is well-connected to flow paths and thus well-supplied with nutrients etc.« less

Three-dimensional conformal versus non-graphic radiation treatment planning for apocrine gland adenocarcinoma of the anal sac in 18 dogs (2002-2007).

PubMed

Keyerleber, M A; Gieger, T L; Erb, H N; Thompson, M S; McEntee, M C

2012-12-01

Differences in dose homogeneity and irradiated volumes of target and surrounding normal tissues between 3D conformal radiation treatment planning and simulated non-graphic manual treatment planning were evaluated in 18 dogs with apocrine gland adenocarcinoma of the anal sac. Overall, 3D conformal treatment planning resulted in more homogenous dose distribution to target tissues with lower hot spots and dose ranges. Dose homogeneity and guarantee of not under-dosing target tissues with 3D conformal planning came at the cost, however, of delivering greater mean doses of radiation and of irradiating greater volumes of surrounding normal tissue structures. © 2011 Blackwell Publishing Ltd.

Trajectory Generation and Path Planning for Autonomous Aerobots

NASA Technical Reports Server (NTRS)

Sharma, Shivanjli; Kulczycki, Eric A.; Elfes, Alberto

2007-01-01

This paper presents global path planning algorithms for the Titan aerobot based on user defined waypoints in 2D and 3D space. The algorithms were implemented using information obtained through a planner user interface. The trajectory planning algorithms were designed to accurately represent the aerobot's characteristics, such as minimum turning radius. Additionally, trajectory planning techniques were implemented to allow for surveying of a planar area based solely on camera fields of view, airship altitude, and the location of the planar area's perimeter. The developed paths allow for planar navigation and three-dimensional path planning. These calculated trajectories are optimized to produce the shortest possible path while still remaining within realistic bounds of airship dynamics.

The accuracy of three-dimensional fused deposition modeling (FDM) compared with three-dimensional CT-Scans on the measurement of the mandibular ramus vertical length, gonion-menton length, and gonial angle

NASA Astrophysics Data System (ADS)

Savitri, I. T.; Badri, C.; Sulistyani, L. D.

2017-08-01

Presurgical treatment planning plays an important role in the reconstruction and correction of defects in the craniomaxillofacial region. The advance of solid freeform fabrication techniques has significantly improved the process of preparing a biomodel using computer-aided design and data from medical imaging. Many factors are implicated in the accuracy of the 3D model. To determine the accuracy of three-dimensional fused deposition modeling (FDM) models compared with three-dimensional CT scans in the measurement of the mandibular ramus vertical length, gonion-menton length, and gonial angle. Eight 3D models were produced from the CT scan data (DICOM file) of eight patients at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Indonesia, Cipto Mangunkusumo Hospital. Three measurements were done three times by two examiners. The measurements of the 3D CT scans were made using OsiriX software, while the measurements of the 3D models were made using a digital caliper and goniometry. The measurement results were then compared. There is no significant difference between the measurements of the mandibular ramus vertical length, gonion-menton length, and gonial angle using 3D CT scans and FDM 3D models. FDM 3D models are considered accurate and are acceptable for clinical applications in dental and craniomaxillofacial surgery.

Comparison of 3DCRT,VMAT and IMRT techniques in metastatic vertebra radiotherapy: A phantom Study

NASA Astrophysics Data System (ADS)

Gedik, Sonay; Tunc, Sema; Kahraman, Arda; Kahraman Cetintas, Sibel; Kurt, Meral

2017-09-01

Vertebra metastases can be seen during the prognosis of cancer patients. Treatment ways of the metastasis are radiotherapy, chemotherapy and surgery. Three-dimensional conformal therapy (3D-CRT) is widely used in the treatment of vertebra metastases. Also, Intensity Modulated Radiotherapy (IMRT) and Volumetric Arc Therapy (VMAT) are used too. The aim of this study is to examine the advantages and disadvantages of the different radiotherapy techniques. In the aspect of this goal, it is studied with a randophantom in Uludag University Medicine Faculty, Radiation Oncology Department. By using a computerized tomography image of the phantom, one 3DCRT plan, two VMAT and three IMRT plans for servical vertebra and three different 3DCRT plans, two VMAT and two IMRT plans for lomber vertebra are calculated. To calculate 3DCRT plans, CMS XiO Treatment System is used and to calculate VMAT and IMRT plans Monaco Treatment Planning System is used in the department. The study concludes with the dosimetric comparison of the treatment plans in the spect of critical organ doses, homogeneity and conformity index. As a result of this study, all critical organ doses are suitable for QUANTEC Dose Limit Report and critical organ doses depend on the techniques which used in radiotherapy. According to homogeneity and conformity indices, VMAT and IMRT plans are better than one in 3DCRT plans in servical and lomber vertebra radiotherapy plans.

The Surgical Management of Skeletal Disproportion with Lingual Orthodontics and Three-dimensional Planning

PubMed Central

Patel, Krutiben; Kau, Chung How; Waite, Peter D; Celebi, Ahmet Arif

2017-01-01

This case report describes the successful treatment of a 26-year-old Caucasian male with skeletal and dental Class III malocclusion associated with mild maxillary and mandibular crowding. The patient had anteroposterior and transverse discrepancies with a reverse overjet and bilateral posterior crossbites. The nonextraction treatment plan included aligning and leveling of the teeth in both arches, Le Fort I and bilateral sagittal split osteotomies, and postsurgical correction of the malocclusion. Orthodontic treatment was initiated with custom lingual appliances followed by orthognathic surgery planned with virtual surgical planning. Treatment was concluded with detailed orthodontic finishing, achieving optimum esthetics and function. PMID:28713747

Three-dimensional planning and use of patient-specific guides improve glenoid component position: an in vitro study.

PubMed

Walch, Gilles; Vezeridis, Peter S; Boileau, Pascal; Deransart, Pierric; Chaoui, Jean

2015-02-01

Glenoid component positioning is a key factor for success in total shoulder arthroplasty. Three-dimensional (3D) measurements of glenoid retroversion, inclination, and humeral head subluxation are helpful tools for preoperative planning. The purpose of this study was to assess the reliability and precision of a novel surgical method for placing the glenoid component with use of patient-specific templates created by preoperative surgical planning and 3D modeling. A preoperative computed tomography examination of cadaveric scapulae (N = 18) was performed. The glenoid implants were virtually placed, and patient-specific guides were created to direct the guide pin into the desired orientation and position in the glenoid. The 3D orientation and position of the guide pin were evaluated by performing a postoperative computed tomography scan for each scapula. The differences between the preoperative planning and the achieved result were analyzed. The mean error in 3D orientation of the guide pin was 2.39°, the mean entry point position error was 1.05 mm, and the mean inclination angle error was 1.42°. The average error in the version angle was 1.64°. There were no technical difficulties or complications related to use of patient-specific guides for guide pin placement. Quantitative analysis of guide pin positioning demonstrated a good correlation between preoperative planning and the achieved position of the guide pin. This study demonstrates the reliability and precision of preoperative planning software and patient-specific guides for glenoid component placement in total shoulder arthroplasty. Copyright © 2015. Published by Elsevier Inc.

Absence of long range order in SrDy2O4 frustrated magnet due to trapped defects from a dimensionality crossover

NASA Astrophysics Data System (ADS)

Gauthier, Nicolas; Fennell, Amy; Uldry, Anne-Christine; Delley, Bernard; Sibille, Romain; White, Jonathan; Niedermayer, Christof; Pomjakushin, Vladimir; Kenzelmann, Michel; Prevost, Bobby; Desilets-Benoit, Alexandre; Bianchi, Andrea D.; Dabkowska, Hanna A.; Nilsen, Goran; Regnault, Louis-Pierre

The simultaneous occurence of geometrical frustration and low dimensionality can lead to strongly correlated fluctuating ground states. In the SrLn2O4 compounds, the Ln magnetic ions form one-dimensional (1D) zig-zag chains that have both of these characteristics, offering a playground to study novel states of matter. In SrDy2O4, the two inequivalent Dy3+ sites are Ising-like with perpendicular easy-axes, favouring the decoupling of neighbouring zig-zag chains. No long range order is observed down to T = 60 mK in zero field but diffuse neutron scattering indicates short range correlations that are consistent with those of the 1D Ising zig-zag chain model. AC susceptibility measurements indicate a slowing down of the fluctuations at low temperatures. We attribute this behaviour to the domain walls in the zig-zag chains. Experimental evidence of a dimensionality crossover at low temperatures in SrDy2O4 suggest that the domains walls are trapped because of interchain interactions, precluding long-range order to the lowest temperatures.

An image-guided planning system for endosseous oral implants.

PubMed

Verstreken, K; Van Cleynenbreugel, J; Martens, K; Marchal, G; van Steenberghe, D; Suetens, P

1998-10-01

A preoperative planning system for oral implant surgery was developed which takes as input computed tomographies (CT's) of the jaws. Two-dimensional (2-D) reslices of these axial CT slices orthogonal to a curve following the jaw arch are computed and shown together with three-dimensional (3-D) surface rendered models of the bone and computer-aided design (CAD)-like implant models. A technique is developed for scanning and visualizing an eventual existing removable prosthesis together with the bone structures. Evaluation of the planning done with the system shows a difference between 2-D and 3-D planning methods. Validation studies measure the benefits of the 3-D approach by comparing plans made in 2-D mode only with those further adjusted using the full 3-D visualization capabilities of the system. The benefits of a 3-D approach are then evident where a prosthesis is involved in the planning. For the majority of the patients, clinically important adjustments and optimizations to the 2-D plans are made once the 3-D visualization is enabled, effectively resulting in a better plan. The alterations are related to bone quality and quantity (p < 0.05), biomechanics (p < 0.005), and esthetics (p < 0.005), and are so obvious that the 3-D plan stands out clearly (p < 0.005). The improvements often avoid complications such as mandibular nerve damage, sinus perforations, fenestrations, or dehiscences.

EUROPA2: Plan Database Services for Planning and Scheduling Applications

NASA Technical Reports Server (NTRS)

Bedrax-Weiss, Tania; Frank, Jeremy; Jonsson, Ari; McGann, Conor

2004-01-01

NASA missions require solving a wide variety of planning and scheduling problems with temporal constraints; simple resources such as robotic arms, communications antennae and cameras; complex replenishable resources such as memory, power and fuel; and complex constraints on geometry, heat and lighting angles. Planners and schedulers that solve these problems are used in ground tools as well as onboard systems. The diversity of planning problems and applications of planners and schedulers precludes a one-size fits all solution. However, many of the underlying technologies are common across planning domains and applications. We describe CAPR, a formalism for planning that is general enough to cover a wide variety of planning and scheduling domains of interest to NASA. We then describe EUROPA(sub 2), a software framework implementing CAPR. EUROPA(sub 2) provides efficient, customizable Plan Database Services that enable the integration of CAPR into a wide variety of applications. We describe the design of EUROPA(sub 2) from the perspective of both modeling, customization and application integration to different classes of NASA missions.

Preoperative three-dimensional model creation of magnetic resonance brain images as a tool to assist neurosurgical planning.

PubMed

Spottiswoode, B S; van den Heever, D J; Chang, Y; Engelhardt, S; Du Plessis, S; Nicolls, F; Hartzenberg, H B; Gretschel, A

2013-01-01

Neurosurgeons regularly plan their surgery using magnetic resonance imaging (MRI) images, which may show a clear distinction between the area to be resected and the surrounding healthy brain tissue depending on the nature of the pathology. However, this distinction is often unclear with the naked eye during the surgical intervention, and it may be difficult to infer depth and an accurate volumetric interpretation from a series of MRI image slices. In this work, MRI data are used to create affordable patient-specific 3-dimensional (3D) scale models of the brain which clearly indicate the location and extent of a tumour relative to brain surface features and important adjacent structures. This is achieved using custom software and rapid prototyping. In addition, functionally eloquent areas identified using functional MRI are integrated into the 3D models. Preliminary in vivo results are presented for 2 patients. The accuracy of the technique was estimated both theoretically and by printing a geometrical phantom, with mean dimensional errors of less than 0.5 mm observed. This may provide a practical and cost-effective tool which can be used for training, and during neurosurgical planning and intervention. Copyright © 2013 S. Karger AG, Basel.

Holography and the Coleman-Mermin-Wagner theorem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anninos, Dionysios; Hartnoll, Sean A.; Iqbal, Nabil

2010-09-15

In 2+1 dimensions at finite temperature, spontaneous symmetry breaking of global symmetries is precluded by large thermal fluctuations of the order parameter. The holographic correspondence implies that analogous effects must also occur in 3+1 dimensional theories with gauged symmetries in certain curved spacetimes with horizon. By performing a one loop computation in the background of a holographic superconductor, we show that bulk quantum fluctuations wash out the classical order parameter at sufficiently large distance scales. The low temperature phase is seen to exhibit algebraic long-range order. Beyond the specific example we study, holography suggests that IR singular quantum fluctuations ofmore » the fields and geometry will play an interesting role for many 3+1 dimensional asymptotically anti-de Sitter spacetimes with planar horizon.« less

75 FR 74742 - Notice of Intent To Prepare an Environmental Assessment for the Proposed North Highway 20 Travel...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

...) which may include an amendment to the 1981 Sun Valley Management Framework Plan (MFP) and by this notice... west and Craters of the Moon National Monument and Preserve and Fish Creek on the east. The Sun Valley...'' designation precludes OHV travel altogether. The OHV designations in the Sun Valley MFP would be amended as a...

The Reserve Forces Impact on Theater Security Cooperation

DTIC Science & Technology

2013-03-01

in South America there are needs for purification is spoiled water, prophylactics, and typhoid , malaria, and yellow fever vaccines. Professions...Theater Security Cooperation (TSC) is a Phase 0 ( shaping ) instrument of regional commanders and is applied with the intent of precluding the use of...military force. The U.S. Army War College (USAWC) Theater Campaign Planning Handbook describes Phase 0 operations as “those shaping activities

Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trevisan, Gregorio L.; Lao, Lang L.; Evans, Todd E.

The Small Angle Slot (SAS) was recently installed on DIII-D as an advanced divertor, promising easier plasma detachment and lower temperatures across the whole target. A twofold study of the SAS magnetic topology is presented in this paper. On one hand, a twodimensional uncertainty quantification analysis is carried out through a Monte Carlo approach in order to understand the level of accuracy of two-dimensional equilibrium computations in reconstructing the strike point and angle onto the divertor. Under typical experimental conditions, the uncertainties are found to be roughly 6.8 mm and 0.56 deg, respectively. On the other hand, a three-dimensional “vacuum”more » analysis is carried out to understand the effects of typical external perturbation fields on the scrape-off layer topology. When the threedimensional I-coils are switched on, poloidally-localized lobes are found to appear, grow, and hit the SAS target, although barely, even for 5 kA; at the same time, the strike point modulation is found to be roughly 1.8 mm and thus negligible for most purposes. Furthermore, such results complement previous two-dimensional analyses in characterizing typical SAS equilibria and provide useful background information for planning and interpreting SAS experiments.« less

Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology

DOE PAGES

Trevisan, Gregorio L.; Lao, Lang L.; Evans, Todd E.; ...

2018-01-04

The Small Angle Slot (SAS) was recently installed on DIII-D as an advanced divertor, promising easier plasma detachment and lower temperatures across the whole target. A twofold study of the SAS magnetic topology is presented in this paper. On one hand, a twodimensional uncertainty quantification analysis is carried out through a Monte Carlo approach in order to understand the level of accuracy of two-dimensional equilibrium computations in reconstructing the strike point and angle onto the divertor. Under typical experimental conditions, the uncertainties are found to be roughly 6.8 mm and 0.56 deg, respectively. On the other hand, a three-dimensional “vacuum”more » analysis is carried out to understand the effects of typical external perturbation fields on the scrape-off layer topology. When the threedimensional I-coils are switched on, poloidally-localized lobes are found to appear, grow, and hit the SAS target, although barely, even for 5 kA; at the same time, the strike point modulation is found to be roughly 1.8 mm and thus negligible for most purposes. Furthermore, such results complement previous two-dimensional analyses in characterizing typical SAS equilibria and provide useful background information for planning and interpreting SAS experiments.« less

Construction of the Seven Basic Crystallographic Units.

ERIC Educational Resources Information Center

Li, Thomas; Worrell, Jay H.

1989-01-01

Presents an exercise to get students more intimately involved in the three dimensional nature of basic units by constructing models. Uses balsa wood, glue, sandpaper, and a square. Studies seven crystals: cubic, hexagonal, monoclinic, orthorhombic, rhombohedral, tetragonal, and triclinic. Plans are available for a Macintosh computer. (MVL)

Adaptive wall research with two- and three-dimensional models in low speed and transonic tunnels

NASA Technical Reports Server (NTRS)

Lewis, M. C.; Neal, G.; Goodyer, M. J.

1988-01-01

This paper summarises recent research at the University of Southampton into adaptive wall technology and outlines the direction of current efforts. The work is aimed at developing techniques for use in test sections where the top and bottom walls may be adjusted in single curvature. Wall streamlining eliminates, as far as experimentally possible, the top and bottom wall interference in low speed and transonic aerofoil testing. A streamlining technique has been developed for low speeds which allows the testing of swept wing panels in low interference environments. At higher speeds, a comparison of several two-dimensional transonic streamlining algorithms has been made and a technique for streamlining with a choked test section has also been developed. Three-dimensional work has mainly concentrated on tests of sidewall mounted half-wings and the development of the software packages required to assess interference and to adjust the flexible walls. It has been demonstrated that two-dimensional wall adaptation can significantly modify the level of wall interference around relatively large three-dimensional models. The residual interferences are small and are probably amenable to standard post-test correction methods. Tests on a calibrated wing-body model are planned in the near future to further validate the proposed streamlining technique.

Three-Dimensional Wind Profiling of Offshore Wind Energy Areas With Airborne Doppler Lidar

NASA Technical Reports Server (NTRS)

Koch, Grady J.; Beyon, Jeffrey Y.; Cowen, Larry J.; Kavaya, Michael J.; Grant, Michael S.

2014-01-01

A technique has been developed for imaging the wind field over offshore areas being considered for wind farming. This is accomplished with an eye-safe 2-micrometer wavelength coherent Doppler lidar installed in an aircraft. By raster scanning the aircraft over the wind energy area (WEA), a three-dimensional map of the wind vector can be made. This technique was evaluated in 11 flights over the Virginia and Maryland offshore WEAs. Heights above the ocean surface planned for wind turbines are shown to be within the marine boundary layer, and the wind vector is seen to show variation across the geographical area of interest at turbine heights.

The advantages of advanced computer-assisted diagnostics and three-dimensional preoperative planning on implant position in orbital reconstruction.

PubMed

Jansen, Jesper; Schreurs, Ruud; Dubois, Leander; Maal, Thomas J J; Gooris, Peter J J; Becking, Alfred G

2018-04-01

Advanced three-dimensional (3D) diagnostics and preoperative planning are the first steps in computer-assisted surgery (CAS). They are an integral part of the workflow, and allow the surgeon to adequately assess the fracture and to perform virtual surgery to find the optimal implant position. The goal of this study was to evaluate the accuracy and predictability of 3D diagnostics and preoperative virtual planning without intraoperative navigation in orbital reconstruction. In 10 cadaveric heads, 19 complex orbital fractures were created. First, all fractures were reconstructed without preoperative planning (control group) and at a later stage the reconstructions were repeated with the help of preoperative planning. Preformed titanium mesh plates were used for the reconstructions by two experienced oral and maxillofacial surgeons. The preoperative virtual planning was easily accessible for the surgeon during the reconstruction. Computed tomographic scans were obtained before and after creation of the orbital fractures and postoperatively. Using a paired t-test, implant positioning accuracy (translation and rotations) of both groups were evaluated by comparing the planned implant position with the position of the implant on the postoperative scan. Implant position improved significantly (P < 0.05) for translation, yaw and roll in the group with preoperative planning (Table 1). Pitch did not improve significantly (P = 0.78). The use of 3D diagnostics and preoperative planning without navigation in complex orbital wall fractures has a positive effect on implant position. This is due to a better assessment of the fracture, the possibility of virtual surgery and because the planning can be used as a virtual guide intraoperatively. The surgeon has more control in positioning the implant in relation to the rim and other bony landmarks. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Single-arc volumetric-modulated arc therapy (sVMAT) as adjuvant treatment for gastric cancer: Dosimetric comparisons with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xin; Li, Guangjun; Zhang, Yingjie

2013-01-01

To compare the dosimetric differences between the single-arc volumetric-modulated arc therapy (sVMAT), 3-dimensional conformal radiotherapy (3D-CRT), and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for gastric cancer as adjuvant radiotherapy. Twelve patients were retrospectively analyzed. In each patient's case, the parameters were compared based on the dose-volume histogram (DVH) of the sVMAT, 3D-CRT, and IMRT plans, respectively. Three techniques showed similar target dose coverage. The maximum and mean doses of the target were significantly higher in the sVMAT plans than that in 3D-CRT plans and in the 3D-CRT/IMRT plans, respectively, but these differences were clinically acceptable. The IMRT and sVMATmore » plans successfully achieved better target dose conformity, reduced the V{sub 20/30}, and mean dose of the left kidney, as well as the V{sub 20/30} of the liver, compared with the 3D-CRT plans. And the sVMAT technique reduced the V{sub 20} of the liver much significantly. Although the maximum dose of the spinal cord were much higher in the IMRT and sVMAT plans, respectively (mean 36.4 vs 39.5 and 40.6 Gy), these data were still under the constraints. Not much difference was found in the analysis of the parameters of the right kidney, intestine, and heart. The IMRT and sVMAT plans achieved similar dose distribution to the target, but superior to the 3D-CRT plans, in adjuvant radiotherapy for gastric cancer. The sVMAT technique improved the dose sparings of the left kidney and liver, compared with the 3D-CRT technique, but showed few dosimetric advantages over the IMRT technique. Studies are warranted to evaluate the clinical benefits of the VMAT treatment for patients with gastric cancer after surgery in the future.« less

Development of a four-dimensional Monte Carlo dose calculation system for real-time tumor-tracking irradiation with a gimbaled X-ray head.

PubMed

Ishihara, Yoshitomo; Nakamura, Mitsuhiro; Miyabe, Yuki; Mukumoto, Nobutaka; Matsuo, Yukinori; Sawada, Akira; Kokubo, Masaki; Mizowaki, Takashi; Hiraoka, Masahiro

2017-03-01

To develop a four-dimensional (4D) dose calculation system for real-time tumor tracking (RTTT) irradiation by the Vero4DRT. First, a 6-MV photon beam delivered by the Vero4DRT was simulated using EGSnrc. A moving phantom position was directly measured by a laser displacement gauge. The pan and tilt angles, monitor units, and the indexing time indicating the phantom position were also extracted from a log file. Next, phase space data at any angle were created from both the log file and particle data under the dynamic multileaf collimator. Irradiation both with and without RTTT, with the phantom moving, were simulated using several treatment field sizes. Each was compared with the corresponding measurement using films. Finally, dose calculation for each computed tomography dataset of 10 respiratory phases with the X-ray head rotated was performed to simulate the RTTT irradiation (4D plan) for lung, liver, and pancreatic cancer patients. Dose-volume histograms of the 4D plan were compared with those calculated on the single reference respiratory phase without the gimbal rotation [three-dimensional (3D) plan]. Differences between the simulated and measured doses were less than 3% for RTTT irradiation in most areas, except the high-dose gradient. For clinical cases, the target coverage in 4D plans was almost identical to that of the 3D plans. However, the doses to organs at risk in the 4D plans varied at intermediate- and low-dose levels. Our proposed system has acceptable accuracy for RTTT irradiation in the Vero4DRT and is capable of simulating clinical RTTT plans. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

The role of urgency in maladaptive behaviors.

PubMed

Anestis, Michael D; Selby, Edward A; Joiner, Thomas E

2007-12-01

Prior work on maladaptive behaviors has cited impulsivity as a risk factor. The concept of impulsivity, however, fails to address the potential role of negative affect in such behaviors. The UPPS Impulsive Behavior Scale addresses this weakness by dividing impulsivity into four subscales: Urgency, Sensation Seeking, (lack of) Premeditation, and (lack of) Perseverance. We predicted that urgency, defined as the tendency, specifically in the face of negative affect, to act quickly and without planning, would predict elevations on three maladaptive behaviors--excessive reassurance seeking, drinking to cope, and bulimic symptoms as measured by the Eating Disorder Inventory--in both cross-sectional and longitudinal analyses in an undergraduate sample (N=70). Participants were assessed at two time points, 3-4 weeks apart. Urgency significantly predicted all three outcome variables cross-sectionally at both Time 1 and Time 2. Time 1 urgency significantly predicted Time 2 excessive reassurance seeking. Changes in urgency from Time 1 to Time 2 predicted changes in all three outcome variables. Results indicate a clear cross-sectional relationship between urgency and certain maladaptive behaviors. Additionally, some form of longitudinal relationship may exist between these variables, although the use of residual change scores precluded distinction between true change and change due to error.

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.

Target dose conformity in 3-dimensional conformal radiotherapy and intensity modulated radiotherapy.

PubMed

Wu, Vincent W C; Kwong, Dora L W; Sham, Jonathan S T

2004-05-01

Dose conformity to the planning target volume is an important criterion in radiotherapy treatment planning, for which the conformity index is a useful assessment tool. The purpose of this study is to compare the differences in CI for the treatment planning of four cancers including the nasopharynx, oesophagus, lung and prostate. Seventy patients with cancers of nasopharynx (30), oesophagus (15), lung (15) and prostate (10) were recruited. Each of these patients was planned with three sets of treatment plans using the FOCUS treatment planning system: the forward and inverse 3DCRT plans and the IMRT plan. The CI was generated for each treatment plan. The mean CI from each cancer patient group was calculated and compared with the other three cancer groups. The mean value of CI was also compared among the three planning methods. The oesophageal and lung cancers demonstrated relatively higher overall mean CI values (0.64 and 0.62, respectively), whereas that of the nasopharynx and prostate were lower (0.54 and 0.50, respectively). With regards to the planning method groups, the IMRT plans produced the highest overall mean CI (0.62), while those for the forward and inverse 3DCRT were similar (0.57 and 0.55, respectively). For the four selected cancers, oesophageal and lung cancers were easier to conform than the nasopharyngeal and prostate cancers. The IMRT plans were more effective in achieving better dose conformity than that of the 3DCRT.

Ectopic third molars in the sigmoid notch: etiology, diagnostic imaging and treatment options.

PubMed

Hanisch, Marcel; Fröhlich, Leopold F; Kleinheinz, Johannes

2016-12-06

The etiology of ectopic third molars located in the sigmoid notch of the mandible is unclear. Only a few cases have been reported. The aim of this article is to discuss the etiology as well as treatment options and diagnostic imaging techniques. A PubMed and Medline search of the literature from 1965 to 2015 to ectopic third molars in the mandibular notch was performed. Furthermore, a clinical case provided by the authors is reported. Among the eight reviewed cases, two male and six female patients were affected that ranged from 25 to 62 years of age (mean 48.4). Pain and swelling in the preauricular region or trismus but also the absence of symptoms was reported. Only in two of the summarized articles an extra-oral access for the removal of the tooth was used. The etiology seems to be individually different, however dentigerous cysts and chronic inflammation seem to play an important role in their appearance. While previous diagnostic reports described two-dimensional diagnostic imaging, currently the three-dimensional imaging is common for preoperative surgical planning with respect to removing ectopic molars. Ectopic third molars in the mandible are a rare condition. The etiology seems to be individually different. Nowadays, three-dimensional imaging is common for preoperative surgical planning.

An evaluation of three-dimensional photogrammetric and morphometric techniques for estimating volume and mass in Weddell seals Leptonychotes weddellii

PubMed Central

Ruscher-Hill, Brandi; Kirkham, Amy L.; Burns, Jennifer M.

2018-01-01

Body mass dynamics of animals can indicate critical associations between extrinsic factors and population vital rates. Photogrammetry can be used to estimate mass of individuals in species whose life histories make it logistically difficult to obtain direct body mass measurements. Such studies typically use equations to relate volume estimates from photogrammetry to mass; however, most fail to identify the sources of error between the estimated and actual mass. Our objective was to identify the sources of error that prevent photogrammetric mass estimation from directly predicting actual mass, and develop a methodology to correct this issue. To do this, we obtained mass, body measurements, and scaled photos for 56 sedated Weddell seals (Leptonychotes weddellii). After creating a three-dimensional silhouette in the image processing program PhotoModeler Pro, we used horizontal scale bars to define the ground plane, then removed the below-ground portion of the animal’s estimated silhouette. We then re-calculated body volume and applied an expected density to estimate animal mass. We compared the body mass estimates derived from this silhouette slice method with estimates derived from two other published methodologies: body mass calculated using photogrammetry coupled with a species-specific correction factor, and estimates using elliptical cones and measured tissue densities. The estimated mass values (mean ± standard deviation 345±71 kg for correction equation, 346±75 kg for silhouette slice, 343±76 kg for cones) were not statistically distinguishable from each other or from actual mass (346±73 kg) (ANOVA with Tukey HSD post-hoc, p>0.05 for all pairwise comparisons). We conclude that volume overestimates from photogrammetry are likely due to the inability of photo modeling software to properly render the ventral surface of the animal where it contacts the ground. Due to logistical differences between the “correction equation”, “silhouette slicing”, and “cones” approaches, researchers may find one technique more useful for certain study programs. In combination or exclusively, these three-dimensional mass estimation techniques have great utility in field studies with repeated measures sampling designs or where logistic constraints preclude weighing animals. PMID:29320573

Region based route planning - Multi-abstraction route planning based on intermediate level vision processing

NASA Technical Reports Server (NTRS)

Doshi, Rajkumar S.; Lam, Raymond; White, James E.

1989-01-01

Intermediate and high level processing operations are performed on vision data for the organization of images into more meaningful, higher-level topological representations by means of a region-based route planner (RBRP). The RBRP operates in terrain scenarios where some or most of the terrain is occluded, proceeding without a priori maps on the basis of two-dimensional representations and gradient-and-roughness information. Route planning is accomplished by three successive abstractions and yields a detailed point-by-point path by searching only within the boundaries of relatively small regions.

3D Printing Provides a Precise Approach in the Treatment of Tetralogy of Fallot, Pulmonary Atresia with Major Aortopulmonary Collateral Arteries.

PubMed

Anwar, Shafkat; Rockefeller, Toby; Raptis, Demetrios A; Woodard, Pamela K; Eghtesady, Pirooz

2018-02-03

Patients with tetralogy of Fallot, pulmonary atresia, and multiple aortopulmonary collateral arteries (Tet PA MAPCAs) have a wide spectrum of anatomy and disease severity. Management of these patients can be challenging and often require multiple high-risk surgical and interventional catheterization procedures. These interventions are made challenging by complex anatomy that require the proceduralist to mentally reconstruct three-dimensional anatomic relationships from two-dimensional images. Three-dimensional (3D) printing is an emerging medical technology that provides added benefits in the management of patients with Tet PA MAPCAs. When used in combination with current diagnostic modalities and procedures, 3D printing provides a precise approach to the management of these challenging, high-risk patients. Specifically, 3D printing enables detailed surgical and interventional planning prior to the procedure, which may improve procedural outcomes, decrease complications, and reduce procedure-related radiation dose and contrast load.

Development of a linearized unsteady Euler analysis for turbomachinery blade rows

NASA Technical Reports Server (NTRS)

Verdon, Joseph M.; Montgomery, Matthew D.; Kousen, Kenneth A.

1995-01-01

A linearized unsteady aerodynamic analysis for axial-flow turbomachinery blading is described in this report. The linearization is based on the Euler equations of fluid motion and is motivated by the need for an efficient aerodynamic analysis that can be used in predicting the aeroelastic and aeroacoustic responses of blade rows. The field equations and surface conditions required for inviscid, nonlinear and linearized, unsteady aerodynamic analyses of three-dimensional flow through a single, blade row operating within a cylindrical duct, are derived. An existing numerical algorithm for determining time-accurate solutions of the nonlinear unsteady flow problem is described, and a numerical model, based upon this nonlinear flow solver, is formulated for the first-harmonic linear unsteady problem. The linearized aerodynamic and numerical models have been implemented into a first-harmonic unsteady flow code, called LINFLUX. At present this code applies only to two-dimensional flows, but an extension to three-dimensions is planned as future work. The three-dimensional aerodynamic and numerical formulations are described in this report. Numerical results for two-dimensional unsteady cascade flows, excited by prescribed blade motions and prescribed aerodynamic disturbances at inlet and exit, are also provided to illustrate the present capabilities of the LINFLUX analysis.

a Three-Dimensional Simulation and Visualization System for Uav Photogrammetry

NASA Astrophysics Data System (ADS)

Liang, Y.; Qu, Y.; Cui, T.

2017-08-01

Nowadays UAVs has been widely used for large-scale surveying and mapping. Compared with manned aircraft, UAVs are more cost-effective and responsive. However, UAVs are usually more sensitive to wind condition, which greatly influences their positions and orientations. The flight height of a UAV is relative low, and the relief of the terrain may result in serious occlusions. Moreover, the observations acquired by the Position and Orientation System (POS) are usually less accurate than those acquired in manned aerial photogrammetry. All of these factors bring in uncertainties to UAV photogrammetry. To investigate these uncertainties, a three-dimensional simulation and visualization system has been developed. The system is demonstrated with flight plan evaluation, image matching, POS-supported direct georeferencing, and ortho-mosaicing. Experimental results show that the presented system is effective for flight plan evaluation. The generated image pairs are accurate and false matches can be effectively filtered. The presented system dynamically visualizes the results of direct georeferencing in three-dimensions, which is informative and effective for real-time target tracking and positioning. The dynamically generated orthomosaic can be used in emergency applications. The presented system has also been used for teaching theories and applications of UAV photogrammetry.

Internal pilots for a class of linear mixed models with Gaussian and compound symmetric data

PubMed Central

Gurka, Matthew J.; Coffey, Christopher S.; Muller, Keith E.

2015-01-01

SUMMARY An internal pilot design uses interim sample size analysis, without interim data analysis, to adjust the final number of observations. The approach helps to choose a sample size sufficiently large (to achieve the statistical power desired), but not too large (which would waste money and time). We report on recent research in cerebral vascular tortuosity (curvature in three dimensions) which would benefit greatly from internal pilots due to uncertainty in the parameters of the covariance matrix used for study planning. Unfortunately, observations correlated across the four regions of the brain and small sample sizes preclude using existing methods. However, as in a wide range of medical imaging studies, tortuosity data have no missing or mistimed data, a factorial within-subject design, the same between-subject design for all responses, and a Gaussian distribution with compound symmetry. For such restricted models, we extend exact, small sample univariate methods for internal pilots to linear mixed models with any between-subject design (not just two groups). Planning a new tortuosity study illustrates how the new methods help to avoid sample sizes that are too small or too large while still controlling the type I error rate. PMID:17318914

SU-E-T-595: Design of a Graphical User Interface for An In-House Monte Carlo Based Treatment Planning System: Planning and Contouring Tools

DOE Office of Scientific and Technical Information (OSTI.GOV)

EMAM, M; Eldib, A; Lin, M

2014-06-01

Purpose: An in-house Monte Carlo based treatment planning system (MC TPS) has been developed for modulated electron radiation therapy (MERT). Our preliminary MERT planning experience called for a more user friendly graphical user interface. The current work aimed to design graphical windows and tools to facilitate the contouring and planning process. Methods: Our In-house GUI MC TPS is built on a set of EGS4 user codes namely MCPLAN and MCBEAM in addition to an in-house optimization code, which was named as MCOPTIM. Patient virtual phantom is constructed using the tomographic images in DICOM format exported from clinical treatment planning systemsmore » (TPS). Treatment target volumes and critical structures were usually contoured on clinical TPS and then sent as a structure set file. In our GUI program we developed a visualization tool to allow the planner to visualize the DICOM images and delineate the various structures. We implemented an option in our code for automatic contouring of the patient body and lungs. We also created an interface window displaying a three dimensional representation of the target and also showing a graphical representation of the treatment beams. Results: The new GUI features helped streamline the planning process. The implemented contouring option eliminated the need for performing this step on clinical TPS. The auto detection option for contouring the outer patient body and lungs was tested on patient CTs and it was shown to be accurate as compared to that of clinical TPS. The three dimensional representation of the target and the beams allows better selection of the gantry, collimator and couch angles. Conclusion: An in-house GUI program has been developed for more efficient MERT planning. The application of aiding tools implemented in the program is time saving and gives better control of the planning process.« less

Thermal energy storage flight experiments

NASA Technical Reports Server (NTRS)

Namkoong, D.

1989-01-01

Consideration is given to the development of an experimental program to study heat transfer, energy storage, fluid movement, and void location under microgravity. Plans for experimental flight packages containing Thermal Energy Storage (TES) material applicable for advanced solar heat receivers are discussed. Candidate materials for TES include fluoride salts, salt eutectics, silicides, and metals. The development of a three-dimensional computer program to describe TES material behavior undergoing melting and freezing under microgravity is also discussed. The TES experiment concept and plans for ground and flight tests are outlined.

[Three-dimensional modeling of mandibular distraction].

PubMed

Morgon, L A; Trunde, F; Coudert, J L; Disant, F

2003-12-01

Facial hemi-atrophy affects 1 in 4000 or 5000 children. We propose treating this deformation of the 1st branchial arch with the "bone distraction" lengthening technique first described by Ilizarov in the 1950s, which has already been employed with the mandible. We have modelled mandibular distraction in facial hemi-atrophy patients and discuss the benefits of such pre-surgical planning encompassing the assistance of pre- and post-operative as well as surgically coordinated orthodontic therapy. Using X scanner views of a 5 year-old girl patient, we have developed a distraction-simulation software, which makes the pathological side harmonious with the healthy side along the medial sagittal plane. In order to obtain facial symmetry, put bones in balance, and orient the occlusal plane horizontally, essential requisites of occlusal stability, it is necessary: to employ a 2 or 3-dimensional distractor, to pre-plan the distraction and screw positioning, to set up a fixed orthodontic treatment plan prior to beginning distraction therapy.

Path planning algorithms for assembly sequence planning. [in robot kinematics

NASA Technical Reports Server (NTRS)

Krishnan, S. S.; Sanderson, Arthur C.

1991-01-01

Planning for manipulation in complex environments often requires reasoning about the geometric and mechanical constraints which are posed by the task. In planning assembly operations, the automatic generation of operations sequences depends on the geometric feasibility of paths which permit parts to be joined into subassemblies. Feasible locations and collision-free paths must be present for part motions, robot and grasping motions, and fixtures. This paper describes an approach to reasoning about the feasibility of straight-line paths among three-dimensional polyhedral parts using an algebra of polyhedral cones. A second method recasts the feasibility conditions as constraints in a nonlinear optimization framework. Both algorithms have been implemented and results are presented.

Dosimetric study of the protection level of the bone marrow in patients with cervical or endometrial cancer for three radiotherapy techniques - 3D CRT, IMRT and VMAT. Study protocol.

NASA Astrophysics Data System (ADS)

Jodda, Agata; Urbański, Bartosz; Piotrowski, Tomasz; Malicki, Julian

2016-03-01

Background: The paper shows the methodology of an in-phantom study of the protection level of the bone marrow in patients with cervical or endometrial cancer for three radiotherapy techniques: three-dimensional conformal radiotherapy, intensity modulated radiotherapy, and volumetric modulated arc therapy, preceded by the procedures of image guidance. Methods/Design: The dosimetric evaluation of the doses will be performed in an in-house multi-element anthropomorphic phantom of the female pelvic area created by three-dimensional printing technology. The volume and position of the structures will be regulated according to the guidelines from the Bayesian network. The input data for the learning procedure of the model will be obtained from the retrospective analysis of imaging data obtained for 96 patients with endometrial cancer or cervical cancer treated with radiotherapy in our centre in 2008-2013. Three anatomical representations of the phantom simulating three independent clinical cases will be chosen. Five alternative treatment plans (1 × three-dimensional conformal radiotherapy, 2 × intensity modulated radiotherapy and 2 × volumetric modulated arc therapy) will be created for each representation. To simulate image-guided radiotherapy, ten specific recombinations will be designated, for each anatomical representation separately, reflecting possible changes in the volume and position of the phantom components. Discussion: The comparative analysis of planned measurements will identify discrepancies between calculated doses and doses that were measured in the phantom. Finally, differences between the doses cumulated in the hip plates performed by different techniques simulating the gynaecological patients' irradiation of dose delivery will be established. The results of this study will form the basis of the prospective clinical trial that will be designed for the assessment of hematologic toxicity and its correlation with the doses cumulated in the hip plates, for gynaecologic patients undergoing radiation therapy.

Clinical value of patient-specific three-dimensional printing of congenital heart disease: Quantitative and qualitative assessments

PubMed Central

Lau, Ivan Wen Wen; Liu, Dongting; Xu, Lei; Fan, Zhanming

2018-01-01

Objective Current diagnostic assessment tools remain suboptimal in demonstrating complex morphology of congenital heart disease (CHD). This limitation has posed several challenges in preoperative planning, communication in medical practice, and medical education. This study aims to investigate the dimensional accuracy and the clinical value of 3D printed model of CHD in the above three areas. Methods Using cardiac computed tomography angiography (CCTA) data, a patient-specific 3D model of a 20-month-old boy with double outlet right ventricle was printed in Tango Plus material. Pearson correlation coefficient was used to evaluate correlation of the quantitative measurements taken at analogous anatomical locations between the CCTA images pre- and post-3D printing. Qualitative analysis was conducted by distributing surveys to six health professionals (two radiologists, two cardiologists and two cardiac surgeons) and three medical academics to assess the clinical value of the 3D printed model in these three areas. Results Excellent correlation (r = 0.99) was noted in the measurements between CCTA and 3D printed model, with a mean difference of 0.23 mm. Four out of six health professionals found the model to be useful in facilitating preoperative planning, while all of them thought that the model would be invaluable in enhancing patient-doctor communication. All three medical academics found the model to be helpful in teaching, and thought that the students will be able to learn the pathology quicker with better understanding. Conclusion The complex cardiac anatomy can be accurately replicated in flexible material using 3D printing technology. 3D printed heart models could serve as an excellent tool in facilitating preoperative planning, communication in medical practice, and medical education, although further studies with inclusion of more clinical cases are needed. PMID:29561912

Two-Dimensional Computational Model for Wave Rotor Flow Dynamics

NASA Technical Reports Server (NTRS)

Welch, Gerard E.

1996-01-01

A two-dimensional (theta,z) Navier-Stokes solver for multi-port wave rotor flow simulation is described. The finite-volume form of the unsteady thin-layer Navier-Stokes equations are integrated in time on multi-block grids that represent the stationary inlet and outlet ports and the moving rotor passages of the wave rotor. Computed results are compared with three-port wave rotor experimental data. The model is applied to predict the performance of a planned four-port wave rotor experiment. Two-dimensional flow features that reduce machine performance and influence rotor blade and duct wall thermal loads are identified. The performance impact of rounding the inlet port wall, to inhibit separation during passage gradual opening, is assessed.

Three-dimensional-printed cardiac prototypes aid surgical decision-making and preoperative planning in selected cases of complex congenital heart diseases: Early experience and proof of concept in a resource-limited environment.

PubMed

Kappanayil, Mahesh; Koneti, Nageshwara Rao; Kannan, Rajesh R; Kottayil, Brijesh P; Kumar, Krishna

2017-01-01

Three-dimensional. (3D) printing is an innovative manufacturing process that allows computer-assisted conversion of 3D imaging data into physical "printouts" Healthcare applications are currently in evolution. The objective of this study was to explore the feasibility and impact of using patient-specific 3D-printed cardiac prototypes derived from high-resolution medical imaging data (cardiac magnetic resonance imaging/computed tomography [MRI/CT]) on surgical decision-making and preoperative planning in selected cases of complex congenital heart diseases (CHDs). Five patients with complex CHD with previously unresolved management decisions were chosen. These included two patients with complex double-outlet right ventricle, two patients with criss-cross atrioventricular connections, and one patient with congenitally corrected transposition of great arteries with pulmonary atresia. Cardiac MRI was done for all patients, cardiac CT for one; specific surgical challenges were identified. Volumetric data were used to generate patient-specific 3D models. All cases were reviewed along with their 3D models, and the impact on surgical decision-making and preoperative planning was assessed. Accurate life-sized 3D cardiac prototypes were successfully created for all patients. The models enabled radically improved 3D understanding of anatomy, identification of specific technical challenges, and precise surgical planning. Augmentation of existing clinical and imaging data by 3D prototypes allowed successful execution of complex surgeries for all five patients, in accordance with the preoperative planning. 3D-printed cardiac prototypes can radically assist decision-making, planning, and safe execution of complex congenital heart surgery by improving understanding of 3D anatomy and allowing anticipation of technical challenges.

Spacecraft Orbit Design and Analysis (SODA). Version 2.0: User's guide

NASA Technical Reports Server (NTRS)

Stallcup, Scott S.; Davis, John S.; Zsoldos, Jeffrey S.

1991-01-01

The Spacecraft Orbit Design and Analysis (SODA) computer program, Version 2.0, is discussed. SODA is a spaceflight mission planning system that consists of six program modules integrated around a common database and user interface. SODA runs on a VAX/VMS computer with an Evans and Sutherland PS300 graphics workstation. In the current version, three program modules produce an interactive three dimensional animation of one or more satellites in planetary orbit. Satellite visibility and sensor coverage capabilities are also provided. Circular and rectangular, off nadir, fixed and scanning sensors are supported. One module produces an interactive three dimensional animation of the solar system. Another module calculates cumulative satellite sensor coverage and revisit time for one or more satellites. Currently, Earth, Moon, and Mars systems are supported for all modules except the solar system module.

Statistical Analysis of Interactive Surgical Planning Using Shape Descriptors in Mandibular Reconstruction with Fibular Segments

PubMed Central

2016-01-01

This study was performed to quantitatively analyze medical knowledge of, and experience with, decision-making in preoperative virtual planning of mandibular reconstruction. Three shape descriptors were designed to evaluate local differences between reconstructed mandibles and patients’ original mandibles. We targeted an asymmetrical, wide range of cutting areas including the mandibular sidepiece, and defined a unique three-dimensional coordinate system for each mandibular image. The generalized algorithms for computing the shape descriptors were integrated into interactive planning software, where the user can refine the preoperative plan using the spatial map of the local shape distance as a visual guide. A retrospective study was conducted with two oral surgeons and two dental technicians using the developed software. The obtained 120 reconstruction plans show that the participants preferred a moderate shape distance rather than optimization to the smallest. We observed that a visually plausible shape could be obtained when considering specific anatomical features (e.g., mental foramen. mandibular midline). The proposed descriptors can be used to multilaterally evaluate reconstruction plans and systematically learn surgical procedures. PMID:27583465

Aerodynamic design for improved manueverability by use of three-dimensional transonic theory

NASA Technical Reports Server (NTRS)

Mann, M. J.; Campbell, R. L.; Ferris, J. C.

1984-01-01

Improvements in transonic maneuver performance by the use of three-dimensional transonic theory and a transonic design procedure were examined. The FLO-27 code of Jameson and Caughey was used to design a new wing for a fighter configuration with lower drag at transonic maneuver conditions. The wing airfoil sections were altered to reduce the upper-surface shock strength by means of a design procedure which is based on the iterative application of the FLO-27 code. The plan form of the fighter configuration was fixed and had a leading edge sweep of 45 deg and an aspect ratio of 3.28. Wind-tunnel tests were conducted on this configuration at Mach numbers from 0.60 to 0.95 and angles of attack from -2 deg to 17 deg. The transonic maneuver performance of this configuration was evaluated by comparison with a wing designed by empirical methods and a wing designed primarily by two-dimensional transonic theory. The configuration designed by the use of FLO-27 had the same or lower drag than the empirical wing and, for some conditions, lower drag than the two-dimensional design. From some maneuver conditions, the drag of the two-dimensional design was somewhat lower.

Surveying Consumer Satisfaction to Assess Managed-Care Quality: Current Practices

PubMed Central

Gold, Marsha; Wooldridge, Judith

1995-01-01

Growing interest in using consumer satisfaction information to enhance quality of care and promote informed consumer choice has accompanied recent expansions in managed care. This article synthesizes information about consumer satisfaction surveys conducted by managed-care plans, government and other agencies, community groups, and purchasers of care. We discuss survey content, methods, and use of consumer survey information. Differences in the use of consumer surveys preclude one instrument or methodology from meeting all needs. The effectiveness of plan-based surveys could be enhanced by increased information on alternative survey instruments and methods and new methodological studies, such as ones developing risk-adjustment methods. PMID:10151887

Three-dimensional radiotherapy of head and neck and esophageal carcinomas: a monoisocentric treatment technique to achieve improved dose distributions.

PubMed

Ahmad, M; Nath, R

2001-02-20

The specific aim of three-dimensional conformal radiotherapy is to deliver adequate therapeutic radiation dose to the target volume while concomitantly keeping the dose to surrounding and intervening normal tissues to a minimum. The objective of this study is to examine dose distributions produced by various radiotherapy techniques used in managing head and neck tumors when the upper part of the esophagus is also involved. Treatment planning was performed with a three-dimensional (3-D) treatment planning system. Computerized tomographic (CT) scans used by this system to generate isodose distributions and dose-volume histograms were obtained directly from the CT scanner, which is connected via ethernet cabling to the 3-D planning system. These are useful clinical tools for evaluating the dose distribution to the treatment volume, clinical target volume, gross tumor volume, and certain critical organs. Using 6 and 18 MV photon beams, different configurations of standard treatment techniques for head and neck and esophageal carcinoma were studied and the resulting dose distributions were analyzed. Film validation dosimetry in solid-water phantom was performed to assess the magnitude of dose inhomogeneity at the field junction. Real-time dose measurements on patients using diode dosimetry were made and compared with computed dose values. With regard to minimizing radiation dose to surrounding structures (i.e., lung, spinal cord, etc.), the monoisocentric technique gave the best isodose distributions in terms of dose uniformity. The mini-mantle anterior-posterior/posterior-anterior (AP/PA) technique produced grossly non-uniform dose distribution with excessive hot spots. The dose measured on the patient during the treatment agrees to within +/- 5 % with the computed dose. The protocols presented in this work for simulation, immobilization and treatment planning of patients with head and neck and esophageal tumors provide the optimum dose distributions in the target volume with reduced irradiation of surrounding non-target tissues, and can be routinely implemented in a radiation oncology department. The presence of a real-time dose-measuring system plays an important role in verifying the actual delivery of radiation dose.

Three-dimensional landing zone joint capability technology demonstration

NASA Astrophysics Data System (ADS)

Savage, James; Goodrich, Shawn; Ott, Carl; Szoboszlay, Zoltan; Perez, Alfonso; Soukup, Joel; Burns, H. N.

2014-06-01

The Three-Dimensional Landing Zone (3D-LZ) Joint Capability Technology Demonstration (JCTD) is a 27-month program to develop an integrated LADAR and FLIR capability upgrade for USAF Combat Search and Rescue HH-60G Pave Hawk helicopters through a retrofit of current Raytheon AN/AAQ-29 turret systems. The 3D-LZ JCTD builds upon a history of technology programs using high-resolution, imaging LADAR to address rotorcraft cruise, approach to landing, landing, and take-off in degraded visual environments with emphasis on brownout, cable warning and obstacle avoidance, and avoidance of controlled flight into terrain. This paper summarizes ladar development, flight test milestones, and plans for a final flight test demonstration and Military Utility Assessment in 2014.

Use of a Three-Dimensional Model to Optimize a MEDPOR Implant for Delayed Reconstruction of a Suprastructure Maxillectomy Defect

PubMed Central

Echo, Anthony; Wolfswinkel, Erik M.; Weathers, William; McKnight, Aisha; Izaddoost, Shayan

2013-01-01

The use of a three-dimensional (3-D) model has been well described for craniomaxillofacial reconstruction, especially with the preoperative planning of free fibula flaps. This article reports the application of an innovative 3-D model approach for the calculation of the exact contours, angles, length, and general morphology of a prefabricated MEDPOR 2/3 orbital implant for reconstruction of a suprastructure maxillectomy defect. The 3-D model allowed intraoperative modification of the MEDPOR implant which decreased the risk of iatrogenic harm, contamination while also improving aesthetic results and function. With the aid of preoperative 3-D models, porous polypropylene facial implants can be contoured efficiently intraoperatively to precisely reconstruct complex craniomaxillofacial defects. PMID:24436774

Three-Dimensional Printing: Basic Principles and Applications in Medicine and Radiology.

PubMed

Kim, Guk Bae; Lee, Sangwook; Kim, Haekang; Yang, Dong Hyun; Kim, Young-Hak; Kyung, Yoon Soo; Kim, Choung-Soo; Choi, Se Hoon; Kim, Bum Joon; Ha, Hojin; Kwon, Sun U; Kim, Namkug

2016-01-01

The advent of three-dimensional printing (3DP) technology has enabled the creation of a tangible and complex 3D object that goes beyond a simple 3D-shaded visualization on a flat monitor. Since the early 2000s, 3DP machines have been used only in hard tissue applications. Recently developed multi-materials for 3DP have been used extensively for a variety of medical applications, such as personalized surgical planning and guidance, customized implants, biomedical research, and preclinical education. In this review article, we discuss the 3D reconstruction process, touching on medical imaging, and various 3DP systems applicable to medicine. In addition, the 3DP medical applications using multi-materials are introduced, as well as our recent results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence, T.S.; Robertson, J.M.; Anscher, M.S.

Radiation-induced liver disease (RILD), often called radiation hepatitis, is a syndrome characterized by the development of anicteric ascites approximately 2 weeks to 4 months after hepatic irradiation. There has been a renewed interest in hepatic irradiation because of two significant advances in cancer treatment; three dimensional radiation therapy treatment planning and bone marrow transplantation using total body irradiation. RILD resulting from liver radiation can usually be distinguished clinically from the resulting from the preparative regime associated with bone marrow transplantation. However, both syndromes demonstrate the same pathological lesion; veno-occlusive disease. Recent evidence suggests that elevated transforming growth factor {beta} levelsmore » may play a role in the development of veno-occlusive disease. Three dimensional treatment planning offers the potential to determine the radiation dose and volume dependence of RILD, permitting the safe delivery of high doses of radiation to parts of the liver. The chief therapy for RILD is diuretics, although some advocate steroids of severe cases. The characteristics of RILD permit the development of a grading system modeled after the NCI Acute Common Toxicity Criteria, which incorporates standard criteria of hepatic dysfunction. 64 refs., 5 figs., 1 tab.« less

System and Method for Aiding Pilot Preview, Rehearsal, Review, and Real-Time Visual Acquisition of Flight Mission Progress

NASA Technical Reports Server (NTRS)

Prinzel, III, Lawrence J. (Inventor); Pope, Alan T. (Inventor); Williams, Steven P. (Inventor); Bailey, Randall E. (Inventor); Arthur, Jarvis J. (Inventor); Kramer, Lynda J. (Inventor); Schutte, Paul C. (Inventor)

2012-01-01

Embodiments of the invention permit flight paths (current and planned) to be viewed from various orientations to provide improved path and terrain awareness via graphical two-dimensional or three-dimensional perspective display formats. By coupling the flight path information with a terrain database, uncompromising terrain awareness relative to the path and ownship is provided. In addition, missed approaches, path deviations, and any navigational path can be reviewed and rehearsed before performing the actual task. By rehearsing a particular mission, check list items can be reviewed, terrain awareness can be highlighted, and missed approach procedures can be discussed by the flight crew. Further, the use of Controller Pilot Datalink Communications enables data-linked path, flight plan changes, and Air Traffic Control requests to be integrated into the flight display of the present invention.

Intensity-Modulated Radiotherapy for Craniospinal Irradiation: Target Volume Considerations, Dose Constraints, and Competing Risks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, William; Filion, Edith; Roberge, David

2007-09-01

Purpose: To report the results of an analysis of dose received to tissues and organs outside the target volume, in the setting of spinal axis irradiation for the treatment of medulloblastoma, using three treatment techniques. Methods and Materials: Treatment plans (total dose, 23.4 Gy) for a standard two-dimensional (2D) technique, a three-dimensional (3D) technique using a 3D imaging-based target volume, and an intensity-modulated radiotherapy (IMRT) technique, were compared for 3 patients in terms of dose-volume statistics for target coverage, as well as organ at risk (OAR) and overall tissue sparing. Results: Planning target volume coverage and dose homogeneity was superiormore » for the IMRT plans for V{sub 95%} (IMRT, 100%; 3D, 96%; 2D, 98%) and V{sub 107%} (IMRT, 3%; 3D, 38%; 2D, 37%). In terms of OAR sparing, the IMRT plan was better for all organs and whole-body contour when comparing V{sub 10Gy}, V{sub 15Gy}, and V{sub 20Gy}. The 3D plan was superior for V{sub 5Gy} and below. For the heart and liver in particular, the IMRT plans provided considerable sparing in terms of V{sub 10Gy} and above. In terms of the integral dose, the IMRT plans were superior for liver (IMRT, 21.9 J; 3D, 28.6 J; 2D, 38.6 J) and heart (IMRT, 9 J; 3D, 14.1J; 2D, 19.4 J), the 3D plan for the body contour (IMRT, 349 J; 3D, 337 J; 2D, 555 J). Conclusions: Intensity-modulated radiotherapy is a valid treatment option for spinal axis irradiation. We have shown that IMRT results in sparing of organs at risk without a significant increase in integral dose.« less

Dosimetric comparison of standard three-dimensional conformal radiotherapy followed by intensity-modulated radiotherapy boost schedule (sequential IMRT plan) with simultaneous integrated boost-IMRT (SIB IMRT) treatment plan in patients with localized carcinoma prostate.

PubMed

Bansal, A; Kapoor, R; Singh, S K; Kumar, N; Oinam, A S; Sharma, S C

2012-07-01

DOSIMETERIC AND RADIOBIOLOGICAL COMPARISON OF TWO RADIATION SCHEDULES IN LOCALIZED CARCINOMA PROSTATE: Standard Three-Dimensional Conformal Radiotherapy (3DCRT) followed by Intensity Modulated Radiotherapy (IMRT) boost (sequential-IMRT) with Simultaneous Integrated Boost IMRT (SIB-IMRT). Thirty patients were enrolled. In all, the target consisted of PTV P + SV (Prostate and seminal vesicles) and PTV LN (lymph nodes) where PTV refers to planning target volume and the critical structures included: bladder, rectum and small bowel. All patients were treated with sequential-IMRT plan, but for dosimetric comparison, SIB-IMRT plan was also created. The prescription dose to PTV P + SV was 74 Gy in both strategies but with different dose per fraction, however, the dose to PTV LN was 50 Gy delivered in 25 fractions over 5 weeks for sequential-IMRT and 54 Gy delivered in 27 fractions over 5.5 weeks for SIB-IMRT. The treatment plans were compared in terms of dose-volume histograms. Also, Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) obtained with the two plans were compared. The volume of rectum receiving 70 Gy or more (V > 70 Gy) was reduced to 18.23% with SIB-IMRT from 22.81% with sequential-IMRT. SIB-IMRT reduced the mean doses to both bladder and rectum by 13% and 17%, respectively, as compared to sequential-IMRT. NTCP of 0.86 ± 0.75% and 0.01 ± 0.02% for the bladder, 5.87 ± 2.58% and 4.31 ± 2.61% for the rectum and 8.83 ± 7.08% and 8.25 ± 7.98% for the bowel was seen with sequential-IMRT and SIB-IMRT plans respectively. For equal PTV coverage, SIB-IMRT markedly reduced doses to critical structures, therefore should be considered as the strategy for dose escalation. SIB-IMRT achieves lesser NTCP than sequential-IMRT.

Virtual surgical planning and three-dimensional printing in multidisciplinary oncologic chest wall resection and reconstruction: A case report.

PubMed

Sharaf, Basel; Sabbagh, M Diya; Vijayasekaran, Aparna; Allen, Mark; Matsumoto, Jane

2018-04-30

Primary sarcomas of the sternum are extremely rare and present the surgical teams involved with unique challenges. Historically, local muscle flaps have been utilized to reconstruct the resulting defect. However, when the resulting oncologic defect is larger than anticipated, local tissues have been radiated, or when preservation of chest wall muscles is necessary to optimize function, local reconstructive options are unsuitable. Virtual surgical planning (VSP) and in house three-dimensional (3D) printing provides the platform for improved understanding of the anatomy of complex tumours, communication amongst surgeons, and meticulous pre-operative planning. We present the novel use of this technology in the multidisciplinary surgical care of a 35 year old male with primary sarcoma of the sternum. Emphasis on minimizing morbidity, maintaining function of chest wall muscles, and preservation of the internal mammary vessels for microvascular anastomosis are discussed. While the majority of patients at our institution receive local or regional flaps for reconstruction of thoracic defects, advances in microvascular surgery allow the reconstructive surgeon the latitude to choose other flap options if necessary. VSP and 3D printing allowed the surgical team involved to utilize free tissue transfer to reconstruct the defect with free tissue transfer from the thigh. Perseveration of the internal mammary vessels was paramount during tumor extirpation. Virtual surgical planning and rapid prototyping is a useful adjunct to standard imaging in complex chest wall resection and reconstruction. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Innovative procedure for computer-assisted genioplasty: three-dimensional cephalometry, rapid-prototyping model and surgical splint.

PubMed

Olszewski, R; Tranduy, K; Reychler, H

2010-07-01

The authors present a new procedure of computer-assisted genioplasty. They determined the anterior, posterior and inferior limits of the chin in relation to the skull and face with the newly developed and validated three-dimensional cephalometric planar analysis (ACRO 3D). Virtual planning of the osteotomy lines was carried out with Mimics (Materialize) software. The authors built a three-dimensional rapid-prototyping multi-position model of the chin area from a medical low-dose CT scan. The transfer of virtual information to the operating room consisted of two elements. First, the titanium plates on the 3D RP model were pre-bent. Second, a surgical guide for the transfer of the osteotomy lines and the positions of the screws to the operating room was manufactured. The authors present the first case of the use of this model on a patient. The postoperative results are promising, and the technique is fast and easy-to-use. More patients are needed for a definitive clinical validation of this procedure. Copyright 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

3D Volume Rendering and 3D Printing (Additive Manufacturing).

PubMed

Katkar, Rujuta A; Taft, Robert M; Grant, Gerald T

2018-07-01

Three-dimensional (3D) volume-rendered images allow 3D insight into the anatomy, facilitating surgical treatment planning and teaching. 3D printing, additive manufacturing, and rapid prototyping techniques are being used with satisfactory accuracy, mostly for diagnosis and surgical planning, followed by direct manufacture of implantable devices. The major limitation is the time and money spent generating 3D objects. Printer type, material, and build thickness are known to influence the accuracy of printed models. In implant dentistry, the use of 3D-printed surgical guides is strongly recommended to facilitate planning and reduce risk of operative complications. Copyright © 2018 Elsevier Inc. All rights reserved.

Force decay and deformation of orthodontic elastomeric ligatures.

PubMed

Taloumis, L J; Smith, T M; Hondrum, S O; Lorton, L

1997-01-01

This study evaluated commercially available molded gray elastomeric ligatures from seven companies for force decay, dimensional change, and the relationship between ligature dimension and force. The initial wall thickness, inside diameter, outside diameter, and force levels of each ligature were measured. Three of four test groups of ligatures were stretched over stainless steel dowels with a circumference approximating that of a large orthodontic twin bracket. Test group 1 was kept at room temperature and humidity for 28 days and test group 2 in a synthetic saliva bath at 37 degrees C, pH 6.84 for 28 days. The residual forces and dimensional changes were measured. The third test group was placed in a synthetic saliva bath at 37 degrees C, pH 6.84, and force levels recorded at initial, 24 hours, 7 days, 14 days, and 28 days. The fourth test group of unstretched samples was placed in a synthetic saliva bath at 37 degrees C, pH 6.84 for 28 days to evaluate dimensional changes due solely to moisture sorption. The results for stretched samples in a simulated oral environment revealed the following: (1) Moisture and heat had a pronounced effect on force decay and permanent deformation, (2) a positive correlation existed between the wall thickness and force, (3) a negative correlation existed between the inside diameter and force, (4) a weak correlation existed between outside diameter and force, (5) the greatest force loss occurred in the first 24 hours and the decay pattern was similar for all ligatures tested, and (6) unstretched ligatures absorbed moisture in the range of 0.060% to 3.15%. The ligatures tested appear to be suitable for use during initial aligning and leveling. However, the rapid force loss and permanent deformation of these products may preclude their use for rotational and torque corrections.

Three-Dimensional Virtual Sonographic Cystoscopy for Detection of Ureterocele in Duplicated Collecting Systems in Children.

PubMed

Nabavizadeh, Behnam; Mozafarpour, Sarah; Hosseini Sharifi, Seyed Hossein; Nabavizadeh, Reza; Abbasioun, Reza; Kajbafzadeh, Abdol-Mohammad

2018-03-01

Ureterocele is a sac-like dilatation of terminal ureter. Precise anatomic delineation is of utmost importance to proceed with the surgical plan, particularly in the ectopic subtype. However, the level of ureterocele extension is not always elucidated by the existing imaging modalities and even by conventional cystoscopy, which is considered as the gold standard for evaluation of ureterocele. This study aims to evaluate the accuracy of three-dimensional virtual sonographic cystoscopy (VSC) in the characterization of ureterocele in duplex collecting systems. Sixteen children with a mean age of 5.1 (standard deviation 1.96) years with transabdominal ultrasonography-proven duplex system and ureterocele were included. They underwent VSC by a single pediatric radiologist. All of them subsequently had conventional cystoscopy, and the results were compared in terms of ureterocele features including anatomy, number, size, location, and extension. Three-dimensional VSC was well tolerated in all cases without any complication. Image quality was suboptimal in 2 of 16 patients. Out of the remaining 14 cases, VSC had a high accuracy in characterization of the ureterocele features (93%). Only the extension of one ureterocele was not precisely detected by VSC. The results of this study suggest three-dimensional sonography as a promising noninvasive diagnostic modality in the evaluation of ectopic ureterocele in children. © 2017 by the American Institute of Ultrasound in Medicine.

TPS(PET)-A TPS-based approach for in vivo dose verification with PET in proton therapy.

PubMed

Frey, K; Bauer, J; Unholtz, D; Kurz, C; Krämer, M; Bortfeld, T; Parodi, K

2014-01-06

Since the interest in ion-irradiation for tumour therapy has significantly increased over the last few decades, intensive investigations are performed to improve the accuracy of this form of patient treatment. One major goal is the development of methods for in vivo dose verification. In proton therapy, a PET (positron emission tomography)-based approach measuring the irradiation-induced tissue activation inside the patient has been already clinically implemented. The acquired PET images can be compared to an expectation, derived under the assumption of a correct treatment application, to validate the particle range and the lateral field position in vivo. In the context of this work, TPSPET is introduced as a new approach to predict proton-irradiation induced three-dimensional positron emitter distributions by means of the same algorithms of the clinical treatment planning system (TPS). In order to perform additional activity calculations, reaction-channel-dependent input positron emitter depth distributions are necessary, which are determined from the application of a modified filtering approach to the TPS reference depth dose profiles in water. This paper presents the implementation of TPSPET on the basis of the research treatment planning software treatment planning for particles. The results are validated in phantom and patient studies against Monte Carlo simulations, and compared to β(+)-emitter distributions obtained from a slightly modified version of the originally proposed one-dimensional filtering approach applied to three-dimensional dose distributions. In contrast to previously introduced methods, TPSPET provides a faster implementation, the results show no sensitivity to lateral field extension and the predicted β(+)-emitter densities are fully consistent to the planned treatment dose as they are calculated by the same pencil beam algorithms. These findings suggest a large potential of the application of TPSPET for in vivo dose verification in the daily clinical routine.

Three dimensional intensity modulated brachytherapy (IMBT): dosimetry algorithm and inverse treatment planning.

PubMed

Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Esquivel, Carlos; Eng, Tony; Papanikolaou, Niko

2010-07-01

The feasibility of intensity modulated brachytherapy (IMBT) to improve dose conformity for irregularly shaped targets has been previously investigated by researchers by means of using partially shielded sources. However, partial shielding does not fully explore the potential of IMBT. The goal of this study is to introduce the concept of three dimensional (3D) intensity modulated brachytherapy and solve two fundamental issues regarding the application of 3D IMBT treatment planning: The dose calculation algorithm and the inverse treatment planning method. A 3D IMBT treatment planning system prototype was developed using the MATLAB platform. This system consists of three major components: (1) A comprehensive IMBT source calibration method with dosimetric inputs from Monte Carlo (EGSnrc) simulations; (2) a "modified TG-43" (mTG-43) dose calculation formalism for IMBT dosimetry; and (3) a physical constraint based inverse IMBT treatment planning platform utilizing a simulated annealing optimization algorithm. The model S700 Axxent electronic brachytherapy source developed by Xoft, Inc. (Fremont, CA), was simulated in this application. Ten intracavitary accelerated partial breast irradiation (APBI) cases were studied. For each case, an "isotropic plan" with only optimized source dwell time and a fully optimized IMBT plan were generated and compared to the original plan in various dosimetric aspects, such as the plan quality, planning, and delivery time. The issue of the mechanical complexity of the IMBT applicator is not addressed in this study. IMBT approaches showed superior plan quality compared to the original plans and tht isotropic plans to different extents in all studied cases. An extremely difficult case with a small breast and a small distance to the ribs and skin, the IMBT plan minimized the high dose volume V200 by 16.1% and 4.8%, respectively, compared to the original and the isotropic plans. The conformity index for the target was increased by 0.13 and 0.04, respectively. The maximum dose to the skin was reduced by 56 and 28 cGy, respectively, per fraction. Also, the maximum dose to the ribs was reduced by 104 and 96 cGy, respectively, per fraction. The mean dose to the ipsilateral and contralateral breasts and lungs were also slightly reduced by the IMBT plan. The limitations of IMBT are the longer planning and delivery time. The IMBT plan took around 2 h to optimize, while the isotropic plan optimization could reach the global minimum within 5 min. The delivery time for the IMBT plan is typically four to six times longer than the corresponding isotropic plan. In this study, a dosimetry method for IMBT sources was proposed and an inverse treatment planning system prototype for IMBT was developed. The improvement of plan quality by 3D IMBT was demonstrated using ten APBI case studies. Faster computers and higher output of the source can further reduce plan optimization and delivery time, respectively.

Planning and simulation of medical robot tasks.

PubMed

Raczkowsky, J; Bohner, P; Burghart, C; Grabowski, H

1998-01-01

Complex techniques for planning and performing surgery revolutionize medical interventions. In former times preoperative planning of interventions usually took place in the surgeons mind. Today's new computer techniques allow the surgeon to discuss various operation methods for a patient and to visualize them three-dimensionally. The use of computer assisted surgical planning helps to get better results of a treatment and supports the surgeon before and during the surgical intervention. In this paper we are presenting our planning and simulation system for operations in maxillo-facial surgery. All phases of a surgical intervention are supported. Chapter 1 gives a description of the medical motivation for our planning system and its environment. In Chapter 2 the basic components are presented. The planning system is depicted in Chapter 3 and a simulation of a robot assisted surgery can be found in Chapter 4. Chapter 5 concludes the paper and gives a survey about our future work.

Comparison of 3D CRT and IMRT Tratment Plans

PubMed Central

Bakiu, Erjona; Telhaj, Ervis; Kozma, Elvisa; Ruçi, Ferdinand; Malkaj, Partizan

2013-01-01

Plans of patients with prostate tumor have been studied. These patients have been scanned in the CT simulator and the images have been sent to the Focal, the system where the doctor delineates the tumor and the organs at risk. After that in the treatment planning system XiO there are created for the same patients three dimensional conformal and intensity modulated radiotherapy treatment plans. The planes are compared according to the dose volume histograms. It is observed that the plans with IMRT technique conform better the isodoses to the planning target volume and protect more the organs at risk, but the time needed to create such plans and to control it is higher than 3D CRT. So it necessary to decide in which patients to do one or the other technique depending on the full dose given to PTV and time consuming in genereral. PMID:24167395

Accuracy of volume measurement using 3D ultrasound and development of CT-3D US image fusion algorithm for prostate cancer radiotherapy.

PubMed

Baek, Jihye; Huh, Jangyoung; Kim, Myungsoo; Hyun An, So; Oh, Yoonjin; Kim, DongYoung; Chung, Kwangzoo; Cho, Sungho; Lee, Rena

2013-02-01

To evaluate the accuracy of measuring volumes using three-dimensional ultrasound (3D US), and to verify the feasibility of the replacement of CT-MR fusion images with CT-3D US in radiotherapy treatment planning. Phantoms, consisting of water, contrast agent, and agarose, were manufactured. The volume was measured using 3D US, CT, and MR devices. A CT-3D US and MR-3D US image fusion software was developed using the Insight Toolkit library in order to acquire three-dimensional fusion images. The quality of the image fusion was evaluated using metric value and fusion images. Volume measurement, using 3D US, shows a 2.8 ± 1.5% error, 4.4 ± 3.0% error for CT, and 3.1 ± 2.0% error for MR. The results imply that volume measurement using the 3D US devices has a similar accuracy level to that of CT and MR. Three-dimensional image fusion of CT-3D US and MR-3D US was successfully performed using phantom images. Moreover, MR-3D US image fusion was performed using human bladder images. 3D US could be used in the volume measurement of human bladders and prostates. CT-3D US image fusion could be used in monitoring the target position in each fraction of external beam radiation therapy. Moreover, the feasibility of replacing the CT-MR image fusion to the CT-3D US in radiotherapy treatment planning was verified.

Computer-Aided Design and Computer-Aided Manufacturing Hydroxyapatite/Epoxide Acrylate Maleic Compound Construction for Craniomaxillofacial Bone Defects.

PubMed

Zhang, Lei; Shen, Shunyao; Yu, Hongbo; Shen, Steve Guofang; Wang, Xudong

2015-07-01

The aim of this study was to investigate the use of computer-aided design and computer-aided manufacturing hydroxyapatite (HA)/epoxide acrylate maleic (EAM) compound construction artificial implants for craniomaxillofacial bone defects. Computed tomography, computer-aided design/computer-aided manufacturing and three-dimensional reconstruction, as well as rapid prototyping were performed in 12 patients between 2008 and 2013. The customized HA/EAM compound artificial implants were manufactured through selective laser sintering using a rapid prototyping machine into the exact geometric shapes of the defect. The HA/EAM compound artificial implants were then implanted during surgical reconstruction. Color-coded superimpositions demonstrated the discrepancy between the virtual plan and achieved results using Geomagic Studio. As a result, the HA/EAM compound artificial bone implants were perfectly matched with the facial areas that needed reconstruction. The postoperative aesthetic and functional results were satisfactory. The color-coded superimpositions demonstrated good consistency between the virtual plan and achieved results. The three-dimensional maximum deviation is 2.12 ± 0.65  mm and the three-dimensional mean deviation is 0.27 ± 0.07  mm. No facial nerve weakness or pain was observed at the follow-up examinations. Only 1 implant had to be removed 2 months after the surgery owing to severe local infection. No other complication was noted during the follow-up period. In conclusion, computer-aided, individually fabricated HA/EAM compound construction artificial implant was a good craniomaxillofacial surgical technique that yielded improved aesthetic results and functional recovery after reconstruction.

A dosimetric phantom study of thoracic radiotherapy based on three-dimensional modeling of mediastinal lymph nodes

PubMed Central

Zhang, Ji-Bin; Zhao, Li-Rong; Cui, Tian-Xiang; Chen, Xie-Wan; Yang, Qiao; Zhou, Yi-Bing; Chen, Zheng-Tang; Zhang, Shao-Xiang; Sun, Jian-Guo

2018-01-01

The aim of the present study was to investigate the optimal strategy and dosimetric measurement of thoracic radiotherapy based on three-dimensional (3D) modeling of mediastinal lymph nodes (MLNs). A 3D model of MLNs was constructed from a Chinese Visible Human female dataset. Image registration and fusion between reconstructed MLNs and original chest computed tomography (CT) images was conducted in the Eclipse™ treatment planning system (TPS). There were three plans, including 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT), which were designed based on 10 cases of simulated lung lesions (SLLs) and MLNs. The quality of these plans was evaluated via examining indexes, including conformity index (CI), homogeneity index and clinical target volume (CTV) coverage. Dose-volume histogram analysis was performed on SLL, MLNs and organs at risk (OARs). A Chengdu Dosimetric Phantom (CDP) was then drilled at specific MLNs according to 20 patients with thoracic tumors and of a medium-build. These plans were repeated on fused MLNs and CDP CT images in the Eclipse™ TPS. Radiation doses at the SLLs and MLNs of the CDP were measured and compared with calculated doses. The established 3D MLN model demonstrated the spatial location of MLNs and adjacent structures. Precise image registration and fusion were conducted between reconstructed MLNs and the original chest CT or CDP CT images. IMRT demonstrated greater values in CI, CTV coverage and OAR (lungs and spinal cord) protection, compared with 3D-CRT and VMAT (P<0.05). The deviation between the measured and calculated doses was within ± 10% at SLL, and at the 2R and 7th MLN stations. In conclusion, the 3D MLN model can benefit plan optimization and dosimetric measurement of thoracic radiotherapy, and when combined with CDP, it may provide a tool for clinical dosimetric monitoring. PMID:29556300

Three dimensional reliability analyses of currently used methods for assessment of sagittal jaw discrepancy

PubMed Central

Almaqrami, Bushra-Sufyan; Alhammadi, Maged-Sultan

2018-01-01

Background The objective of this study was to analyse three dimensionally the reliability and correlation of angular and linear measurements in assessment of anteroposterior skeletal discrepancy. Material and Methods In this retrospective cross sectional study, a sample of 213 subjects were three-dimensionally analysed from cone-beam computed tomography scans. The sample was divided according to three dimensional measurement of anteroposterior relation (ANB angle) into three groups (skeletal Class I, Class II and Class III). The anterior-posterior cephalometric indicators were measured on volumetric images using Anatomage software (InVivo5.2). These measurements included three angular and seven linear measurements. Cross tabulations were performed to correlate the ANB angle with each method. Intra-class Correlation Coefficient (ICC) test was applied for the difference between the two reliability measurements. P value of < 0.05 was considered significant. Results There was a statistically significant (P<0.05) agreement between all methods used with variability in assessment of different anteroposterior relations. The highest correlation was between ANB and DSOJ (0.913), strong correlation with AB/FH, AB/SN/, MM bisector, AB/PP, Wits appraisal (0.896, 0.890, 0.878, 0.867,and 0.858, respectively), moderate with AD/SN and Beta angle (0.787 and 0.760), and weak correlation with corrected ANB angle (0.550). Conclusions Conjunctive usage of ANB angle with DSOJ, AB/FH, AB/SN/, MM bisector, AB/PP and Wits appraisal in 3D cephalometric analysis provide a more reliable and valid indicator of the skeletal anteroposterior relationship. Clinical relevance: Most of orthodontic literature depends on single method (ANB) with its drawbacks in assessment of skeletal discrepancy which is a cardinal factors for proper treatment planning, this study assessed three dimensionally the degree of correlation between all available methods to make clinical judgement more accurate based on more than one method of assessment. Key words:Anteroposterior relationships, ANB angle, Three-dimension, CBCT. PMID:29750096

The University Münster Model Surgery System for Orthognathic Surgery. Part II -- KD-MMS.

PubMed

Ehmer, Ulrike; Joos, Ulrich; Ziebura, Thomas; Flieger, Stefanie; Wiechmann, Dirk

2013-01-04

Model surgery is an integral part of the planning procedure in orthognathic surgery. Most concepts comprise cutting the dental cast off its socket. The standardized spacer plates of the KD-MMS provide for a non-destructive, reversible and reproducible means of maxillary and/or mandibular plaster cast separation. In the course of development of the system various articulator types were evaluated with regard to their capability to provide a means of realizing the concepts comprised of the KD-MMS. Special attention was dedicated to the ability to perform three-dimensional displacements without cutting of plaster casts. Various utilities were developed to facilitate maxillary displacement in accordance to the planning. Objectives of this development comprised the ability to implement the values established in the course of two-dimensional ceph planning. The system - KD-MMS comprises a set of hardware components as well as a defined procedure. Essential hardware components are red spacer and blue mounting plates. The blue mounting plates replace the standard yellow SAM mounting elements. The red spacers provide for a defined leeway of 8 mm for three-dimensional movements. The non-destructive approach of the KD-MMS makes it possible to conduct different model surgeries with the same plaster casts as well as to restore the initial, pre-surgical situation at any time. Thereby, surgical protocol generation and gnathologic splint construction are facilitated. The KD-MMS hardware components in conjunction with the defined procedures are capable of increasing efficiency and accuracy of model surgery and splint construction. In cases where different surgical approaches need to be evaluated in the course of model surgery, a significant reduction of chair time may be achieved.

Experiments in autonomous robotics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamel, W.R.

1987-01-01

The Center for Engineering Systems Advanced Research (CESAR) is performing basic research in autonomous robotics for energy-related applications in hazardous environments. The CESAR research agenda includes a strong experimental component to assure practical evaluation of new concepts and theories. An evolutionary sequence of mobile research robots has been planned to support research in robot navigation, world sensing, and object manipulation. A number of experiments have been performed in studying robot navigation and path planning with planar sonar sensing. Future experiments will address more complex tasks involving three-dimensional sensing, dexterous manipulation, and human-scale operations.

Plan Execution Interchange Language (PLEXIL)

NASA Technical Reports Server (NTRS)

Estlin, Tara; Jonsson, Ari; Pasareanu, Corina; Simmons, Reid; Tso, Kam; Verma, Vandi

2006-01-01

Plan execution is a cornerstone of spacecraft operations, irrespective of whether the plans to be executed are generated on board the spacecraft or on the ground. Plan execution frameworks vary greatly, due to both different capabilities of the execution systems, and relations to associated decision-making frameworks. The latter dependency has made the reuse of execution and planning frameworks more difficult, and has all but precluded information sharing between different execution and decision-making systems. As a step in the direction of addressing some of these issues, a general plan execution language, called the Plan Execution Interchange Language (PLEXIL), is being developed. PLEXIL is capable of expressing concepts used by many high-level automated planners and hence provides an interface to multiple planners. PLEXIL includes a domain description that specifies command types, expansions, constraints, etc., as well as feedback to the higher-level decision-making capabilities. This document describes the grammar and semantics of PLEXIL. It includes a graphical depiction of this grammar and illustrative rover scenarios. It also outlines ongoing work on implementing a universal execution system, based on PLEXIL, using state-of-the-art rover functional interfaces and planners as test cases.

Single line source with and without vaginal loading and the impact on target coverage and organ at risk doses for cervix cancer Stages IB, II, and IIIB: treatment planning simulation in patients treated with MRI-guided adaptive brachytherapy in a multicentre study (EMBRACE).

PubMed

Nkiwane, Karen S; Pötter, Richard; Tanderup, Kari; Federico, Mario; Lindegaard, Jacob C; Kirisits, Christian

2013-01-01

Three-dimensional evaluation and comparison of target and organs at risk (OARs) doses from two traditional standard source loading patterns in the frame of MRI-guided cervical cancer brachytherapy for various clinical scenarios based on patient data collected in a multicenter trial setting. Two nonoptimized three-dimensional MRI-based treatment plans, Plan 1 (tandem and vaginal loading) and Plan 2 (tandem loading only), were generated for 134 patients from seven centers participating in the EMBRACE study. Both plans were normalized to point A (Pt. A). Target and OAR doses were evaluated in terms of minimum dose to 90% of the high-risk clinical target volume (HRCTV D90) grouped by tumor stage and minimum dose to the most exposed 2cm³ of the OARs volume. An HRCTV D90 ≥ Pt. A was achieved in 82% and 44% of the patients with Plans 1 and 2, respectively. Median HRCTV D90 with Plans 1 and 2 was 120% and 90% of Pt. A dose, respectively. Both plans had optimal dose coverage in 88% of Stage IB tumors; however, the tandem-only plan resulted in about 50% of dose reduction to the vagina and rectum. For Stages IIB and IIIB, Plan 1 had on average 35% better target coverage but with significant doses to OARs. Standard tandem loading alone results in good target coverage in most Stage IB tumors without violating OAR dose constraints. For Stage IIB tumors, standard vaginal loading improves the therapeutic window, however needs optimization to fulfill the dose prescription for target and OAR. In Stage IIIB, even optimized vaginal loading often does not fulfill the needs for dose prescription. The significant dose variation across various clinical scenarios for both target and OARs indicates the need for image-guided brachytherapy for optimal dose adaptation both for limited and advanced diseases. Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Numerical solutions of the complete Navier-Strokes equations. no. 27

NASA Technical Reports Server (NTRS)

Hassan, H. A.

1996-01-01

This report describes the development of an enstrophy model capable of predicting turbulence separation and its application to two airfoils at various angles of attack and Mach numbers. In addition, a two equation kappa-xi model with a tensor eddy viscosity was developed. Plans call for this model to be used in calculating three dimensional turbulent flows.

4D BADA-based Trajectory Generator and 3D Guidance Algorithm

NASA Technical Reports Server (NTRS)

Palacios, Eduardo Sepulveda; Johnson, Marcus A.

2013-01-01

This paper presents a hybrid integration between aerodynamic, airline procedures and other BADA-based (Base of Aircraft Data) coefficients with a classical aircraft dynamic model. This paper also describes a three-dimensional guidance algorithm implemented in order to produce commands for the aircraft to follow a flight plan. The software chosen for this work is MATLAB.

Analysis of physical-chemical processes governing SSME internal fluid flows

NASA Technical Reports Server (NTRS)

Singhal, A. K.; Owens, S. F.; Mukerjee, T.; Keeton, L. W.; Prakash, C.; Przekwas, A. J.

1984-01-01

The efforts to adapt CHAM's computational fluid dynamics code, PHOENICS, to the analysis of flow within the high pressure fuel turbopump (HPFTP) aft-platform seal cavity of the SSME are summarized. In particular, the special purpose PHOENICS satellite and ground station specifically formulated for this application are listed and described, and the preliminary results of the first part two-dimensional analyses are presented and discussed. Planned three-dimensional analyses are also briefly outlined. To further understand the mixing and combustion processes in the SSME fuelside preburners, a single oxygen-hydrogen jet element was investigated.

Space Product Development (SPD)

NASA Image and Video Library

2003-06-01

Echocardiography uses sound waves to image the heart and other organs. Developing a compact version of the latest technology improved the ease of monitoring crew member health, a critical task during long space flights. NASA researchers plan to adapt the three-dimensional (3-D) echocardiogram for space flight. The two-dimensional (2-D) echocardiogram utilized in orbit on the International Space Station (ISS) was effective, but difficult to use with precision. A heart image from a 2-D echocardiogram (left) is of a better quality than that from a 3-D device (right), but the 3-D imaging procedure is more user-friendly.

Adaptive Gait Control for a Quadruped Robot on 3D Path Planning

NASA Astrophysics Data System (ADS)

Igarashi, Hiroshi; Kakikura, Masayoshi

A legged walking robot is able to not only move on irregular terrain but also change its posture. For example, the robot can pass under overhead obstacles by crouching. The purpose of our research is to realize efficient path planning with a quadruped robot. Therefore, the path planning is expected to extended in three dimensions because of the mobility. However, some issues of the quadruped robot, which are instability, workspace limitation, deadlock and slippage, complicate realizing such application. In order to improve these issues and reinforce the mobility, a new static gait pattern for a quadruped robot, called TFG: Trajectory Following Gait, is proposed. The TFG intends to obtain high controllability like a wheel robot. Additionally, the TFG allows to change it posture during the walk. In this paper, some experimental results show that the TFG improves the issues and it is available for efficient locomotion in three dimensional environment.

First-principles engineering of charged defects for two-dimensional quantum technologies

NASA Astrophysics Data System (ADS)

Wu, Feng; Galatas, Andrew; Sundararaman, Ravishankar; Rocca, Dario; Ping, Yuan

2017-12-01

Charged defects in two-dimensional (2D) materials have emerging applications in quantum technologies such as quantum emitters and quantum computation. The advancement of these technologies requires a rational design of ideal defect centers, demanding reliable computation methods for the quantitatively accurate prediction of defect properties. We present an accurate, parameter-free, and efficient procedure to evaluate the quasiparticle defect states and thermodynamic charge transition levels of defects in 2D materials. Importantly, we solve critical issues that stem from the strongly anisotropic screening in 2D materials, that have so far precluded the accurate prediction of charge transition levels in these materials. Using this procedure, we investigate various defects in monolayer hexagonal boron nitride (h -BN ) for their charge transition levels, stable spin states, and optical excitations. We identify CBVN (nitrogen vacancy adjacent to carbon substitution of boron) to be the most promising defect candidate for scalable quantum bit and emitter applications.

Efficacy of patient-specific bolus created using three-dimensional printing technique in photon radiotherapy.

PubMed

Fujimoto, Koya; Shiinoki, Takehiro; Yuasa, Yuki; Hanazawa, Hideki; Shibuya, Keiko

2017-06-01

A commercially available bolus ("commercial-bolus") does not make complete contact with the irregularly shaped patient skin. This study aims to customise a patient-specific three-dimensional (3D) bolus using a 3D printing technique ("3D-bolus") and to evaluate its clinical feasibility for photon radiotherapy. The 3D-bolus was designed using a treatment planning system (TPS) in Digital Imaging and Communications in Medicine-Radiotherapy (DICOM-RT) format, and converted to stereolithographic format for printing. To evaluate its physical characteristics, treatment plans were created for water-equivalent phantoms that were bolus-free, or had a flat-form printed 3D-bolus, a TPS-designed bolus ("virtual-bolus"), or a commercial-bolus. These plans were compared based on the percentage depth dose (PDD) and target-volume dose volume histogram (DVH) measurements. To evaluate the clinical feasibility, treatment plans were created for head phantoms that were bolus-free or had a 3D-bolus, a virtual-bolus, or a commercial-bolus. These plans were compared based on the target volume DVH. In the physical evaluation, the 3D-bolus provided effective dose coverage in the build-up region, which was equivalent to the commercial-bolus. With regard to the clinical feasibility, the air gaps were lesser with the 3D-bolus when compared to the commercial-bolus. Furthermore, the prescription dose could be delivered appropriately to the target volume. The 3D-bolus has potential use for air-gap reduction compared to the commercial-bolus and facilitates target-volume dose coverage and homogeneity improvement. A 3D-bolus produced using a 3D printing technique is comparable to a commercial-bolus applied to an irregular-shaped skin surface. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

[Preparation of simulate craniocerebral models via three dimensional printing technique].

PubMed

Lan, Q; Chen, A L; Zhang, T; Zhu, Q; Xu, T

2016-08-09

Three dimensional (3D) printing technique was used to prepare the simulate craniocerebral models, which were applied to preoperative planning and surgical simulation. The image data was collected from PACS system. Image data of skull bone, brain tissue and tumors, cerebral arteries and aneurysms, and functional regions and relative neural tracts of the brain were extracted from thin slice scan (slice thickness 0.5 mm) of computed tomography (CT), magnetic resonance imaging (MRI, slice thickness 1mm), computed tomography angiography (CTA), and functional magnetic resonance imaging (fMRI) data, respectively. MIMICS software was applied to reconstruct colored virtual models by identifying and differentiating tissues according to their gray scales. Then the colored virtual models were submitted to 3D printer which produced life-sized craniocerebral models for surgical planning and surgical simulation. 3D printing craniocerebral models allowed neurosurgeons to perform complex procedures in specific clinical cases though detailed surgical planning. It offered great convenience for evaluating the size of spatial fissure of sellar region before surgery, which helped to optimize surgical approach planning. These 3D models also provided detailed information about the location of aneurysms and their parent arteries, which helped surgeons to choose appropriate aneurismal clips, as well as perform surgical simulation. The models further gave clear indications of depth and extent of tumors and their relationship to eloquent cortical areas and adjacent neural tracts, which were able to avoid surgical damaging of important neural structures. As a novel and promising technique, the application of 3D printing craniocerebral models could improve the surgical planning by converting virtual visualization into real life-sized models.It also contributes to functional anatomy study.

Feasibility study on dosimetry verification of volumetric-modulated arc therapy-based total marrow irradiation.

PubMed

Liang, Yun; Kim, Gwe-Ya; Pawlicki, Todd; Mundt, Arno J; Mell, Loren K

2013-03-04

The purpose of this study was to develop dosimetry verification procedures for volumetric-modulated arc therapy (VMAT)-based total marrow irradiation (TMI). The VMAT based TMI plans were generated for three patients: one child and two adults. The planning target volume (PTV) was defined as bony skeleton, from head to mid-femur, with a 3 mm margin. The plan strategy similar to published studies was adopted. The PTV was divided into head and neck, chest, and pelvic regions, with separate plans each of which is composed of 2-3 arcs/fields. Multiple isocenters were evenly distributed along the patient's axial direction. The focus of this study is to establish a dosimetry quality assurance procedure involving both two-dimensional (2D) and three-dimensional (3D) volumetric verifications, which is desirable for a large PTV treated with multiple isocenters. The 2D dose verification was performed with film for gamma evaluation and absolute point dose was measured with ion chamber, with attention to the junction between neighboring plans regarding hot/cold spots. The 3D volumetric dose verification used commercial dose reconstruction software to reconstruct dose from electronic portal imaging devices (EPID) images. The gamma evaluation criteria in both 2D and 3D verification were 5% absolute point dose difference and 3 mm of distance to agreement. With film dosimetry, the overall average gamma passing rate was 98.2% and absolute dose difference was 3.9% in junction areas among the test patients; with volumetric portal dosimetry, the corresponding numbers were 90.7% and 2.4%. A dosimetry verification procedure involving both 2D and 3D was developed for VMAT-based TMI. The initial results are encouraging and warrant further investigation in clinical trials.

SU-F-T-635: Lung SBRT: Dosimetric and Treatment Time Comparison of Volumetric-Modulated Arc Therapy and Three-Dimensional Conformal Radiotherapy in Clinically Treated Cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, J; Xu, Z; Baker, J

Purpose: To compare three-dimensional conformal radiotherapy (3D CRT) and volumetric-modulated arc therapy (VMAT) in lung stereotactic body radiation therapy (SBRT) Methods: A retrospective study of clinically treated lung SBRT cases treated between 2010 and 2015 at our hospital was performed. All treatment modalities were included in this evaluation (VMAT, 3D CRT, static IMRT, and dynamic conformal arc therapy). However, the majority of treatment modalities were either VMAT or 3D CRT. Treatment times of patients and dosimetric plan quality metrics were compared. Treatment times were calculated based on the time the therapist opened and closed the patient’s treatment plan. This treatmentmore » time closely approximates the utilization time of the treatment room. The dosimetric plan quality metrics evaluated include ICRU conformity index, the volume of 105% prescribed dose outside PTV, the ratio of volume of 50% prescribed dose to the volume of PTV, the percentage of maximum dose at 2 cm away from PTV to the prescribed dose, and the V20 (percentage of lung volume receiving 20 Gy or more). Results: Treatment time comparisons show that on average VMAT has shorter treatment times than 3D CRT. Dose conformity, defined by the ICRU conformity index, and high dose spillage, defined by the volume of 105% dose outside the PTV, is reduced when using VMAT compared to 3D CRT. V20 and intermediate dose spillage/fall-off metrics of VMAT and 3D are not significantly different. Conclusion: Clinically treated lung SBRT cases indicate VMAT is superior to 3D with regard to shorter treatment times, plan dose conformity, and plan high dose spillage.« less

Development of educational programs using Dagik Earth, a four dimensional display of the Earth and planets

NASA Astrophysics Data System (ADS)

Saito, A.; Akiya, Y.; Yoshida, D.; Odagi, Y.; Yoshikawa, M.; Tsugawa, T.; Takahashi, M.; Kumano, Y.; Iwasaki, S.

2010-12-01

We have developed a four-dimensional display system of the Earth and planets to use in schools, science centers, and research institutes. It can display the Earth and planets in three-dimensional way without glasses, and the time variation of the scientific data can be displayed on the Earth and planets image. The system is named Dagik Earth, and educational programs using Dagik Earth have been developed for schools and science centers. Three dimensional displays can show the Earth and planets in exact form without any distortion, which cannot be achieved with two-dimensional display. Furthermore it can provide a sense of reality. There are several systems for the three-dimensional presentation of the Earth, such as Science on a sphere by NOAA, and Geocosmos by Miraikan, Japan. Comparing these systems, the advantage of Dagik Earth is portability and affordability. The system uses ordinary PC and PC projector. Only a spherical screen is the special equipment of Dagik Earth. Therefore Dagik Earth is easy to use in classrooms. Several educational programs have been developed and carried out in high schools, junior high schools, elementary schools and science centers. Several research institutes have used Dagik Earth in their public outreach programs to demonstrate their novel scientific results to public in an attractive way of presentation. A community of users and developers of Dagik Earth is being formed in Japan. In the presentation, the outline of Dagik Earth and the educational programs using Dagik Earth will be presented. Its future plan will also be discussed.

[Usefulness of computed tomography with three-dimensional reconstructions in visualization of cervical spine malformation of a child with Sprengel's deformity].

PubMed

Wawrzynek, Wojciech; Siemianowicz, Anna; Koczy, Bogdan; Kasprowska, Sabina; Besler, Krzysztof

2005-01-01

The Sprengel's deformity is a congenital anomaly of the shoulder girdle with an elevation of the scapula and limitation of movement of the shoulder. Sprengel's deformity is frequently associated with cervical spine malformations such as: spinal synostosis, spina bifida and an abnormal omovertebral fibrous, cartilaginous or osseus connection. The diagnosis of Sprengel's deformity is based on a clinical examination and radiological procedures. In every case of Sprengel's deformity plain radiography and computed tomography should be performed. Three-dimensional (3D) reconstructions allow to visualize precise topography and spatial proportions of examined bone structures. 3D reconstruction also enables an optional rotation of visualized bone structures in order to clarify the anatomical abnormalities and to plan surgical treatment.

Feature integration theory revisited: dissociating feature detection and attentional guidance in visual search.

PubMed

Chan, Louis K H; Hayward, William G

2009-02-01

In feature integration theory (FIT; A. Treisman & S. Sato, 1990), feature detection is driven by independent dimensional modules, and other searches are driven by a master map of locations that integrates dimensional information into salience signals. Although recent theoretical models have largely abandoned this distinction, some observed results are difficult to explain in its absence. The present study measured dimension-specific performance during detection and localization, tasks that require operation of dimensional modules and the master map, respectively. Results showed a dissociation between tasks in terms of both dimension-switching costs and cross-dimension attentional capture, reflecting a dimension-specific nature for detection tasks and a dimension-general nature for localization tasks. In a feature-discrimination task, results precluded an explanation based on response mode. These results are interpreted to support FIT's postulation that different mechanisms are involved in parallel and focal attention searches. This indicates that the FIT architecture should be adopted to explain the current results and that a variety of visual attention findings can be addressed within this framework. Copyright 2009 APA, all rights reserved.

DOD (USAF) turbulence accidents and incidents

NASA Technical Reports Server (NTRS)

Miller, Douglas

1987-01-01

A summary of Air Force turbulence related mishaps for the last ten years of Air Force mishaps is presented from a perspective of where it has been, where it is now, and where it is going. In addition to accounts of major mishaps, a summary of what actions were taken to preclude future similar mishaps is presented. Also, a discussion of some of the things being done now and being planned for the future to prevent turbulence related mishaps is presented.

Transvaginal Ultrasound-Guided Biopsy of Deep Pelvic Masses: How We Do It.

PubMed

Plett, Sara K; Poder, Liina; Brooks, Rebecca A; Morgan, Tara A

2016-06-01

The purpose of this review is to discuss the rationale and indications for transvaginal ultrasound-guided biopsy. Transvaginal ultrasound-guided biopsy can be a helpful tool for diagnosis and treatment planning in the evaluation of pelvic masses, particularly when the anatomy precludes a transabdominal or posterior transgluteal percutaneous biopsy approach. A step-by-step summary of the technique with preprocedure and postprocedure considerations is included. © 2016 by the American Institute of Ultrasound in Medicine.

Three-dimensional printing in cardiac surgery and interventional cardiology: a single-centre experience.

PubMed

Schmauss, Daniel; Haeberle, Sandra; Hagl, Christian; Sodian, Ralf

2015-06-01

In individual cases, routine preoperative imaging might not be sufficient for optimal planning of cardiovascular procedures. Three-dimensional printing (3D), a widely used technique to build life-like replicas of anatomical structures that has proven value in different medical disciplines, might overcome these shortcomings. However, data on 3D printing in cardiovascular medicine are limited to single reports. This stimulated us to present our single-centre experience with 3D printing models in cardiac surgery and interventional cardiology. Between the years 2006 and 2013, we fabricated 3D printing models using preoperative computed tomography or magnetic resonance imaging data in paediatric and adult cardiac surgery, as well as interventional cardiology. We present the 8 most representative cases. The models were very helpful for perioperative planning and orientation, as well as simulation of procedures due to the exact and life-like illustration of the cardiovascular anatomy. The fabrication of 3D printing models is feasible for perioperative planning and simulation in a variety of complex cases in paediatric and adult cardiac surgery, as well as in interventional cardiology. Further studies including more patients and providing more data are expected to demonstrate that the use of 3D printing may decrease morbidity and mortality of complex, non-routine procedures in cardiovascular medicine. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Three-dimensional cluster formation and structure in heterogeneous dose distribution of intensity modulated radiation therapy.

PubMed

Chao, Ming; Wei, Jie; Narayanasamy, Ganesh; Yuan, Yading; Lo, Yeh-Chi; Peñagarícano, José A

2018-05-01

To investigate three-dimensional cluster structure and its correlation to clinical endpoint in heterogeneous dose distributions from intensity modulated radiation therapy. Twenty-five clinical plans from twenty-one head and neck (HN) patients were used for a phenomenological study of the cluster structure formed from the dose distributions of organs at risks (OARs) close to the planning target volumes (PTVs). Initially, OAR clusters were searched to examine the pattern consistence among ten HN patients and five clinically similar plans from another HN patient. Second, clusters of the esophagus from another ten HN patients were scrutinized to correlate their sizes to radiobiological parameters. Finally, an extensive Monte Carlo (MC) procedure was implemented to gain deeper insights into the behavioral properties of the cluster formation. Clinical studies showed that OAR clusters had drastic differences despite similar PTV coverage among different patients, and the radiobiological parameters failed to positively correlate with the cluster sizes. MC study demonstrated the inverse relationship between the cluster size and the cluster connectivity, and the nonlinear changes in cluster size with dose thresholds. In addition, the clusters were insensitive to the shape of OARs. The results demonstrated that the cluster size could serve as an insightful index of normal tissue damage. The clinical outcome of the same dose-volume might be potentially different. Copyright © 2018 Elsevier B.V. All rights reserved.

Three-dimensional magnetic resonance imaging based on time-of-flight magnetic resonance angiography for superficial cerebral arteriovenous malformation--technical note.

PubMed

Murata, Takahiro; Horiuchi, Tetsuyoshi; Rahmah, Nunung Nur; Sakai, Keiichi; Hongo, Kazuhiro

2011-01-01

Direct surgery remains important for the treatment of superficial cerebral arteriovenous malformation (AVM). Surgical planning on the basis of careful analysis from various neuroimaging modalities can aid in resection of superficial AVM with favorable outcome. Three-dimensional (3D) magnetic resonance (MR) imaging reconstructed from time-of-flight (TOF) MR angiography was developed as an adjunctive tool for surgical planning of superficial AVM. 3-T TOF MR imaging without contrast medium was performed preoperatively in patients with superficial AVM. The images were imported into OsiriX imaging software and the 3D reconstructed MR image was produced using the volume rendering method. This 3D MR image could clearly visualize the surface angioarchitecture of the AVM with the surrounding brain on a single image, and clarified feeding arteries including draining veins and the relationship with sulci or fissures surrounding the nidus. 3D MR image of the whole AVM angioarchitecture was also displayed by skeletonization of the surrounding brain. Preoperative 3D MR image corresponded to the intraoperative view. Feeders on the brain surface were easily confirmed and obliterated during surgery, with the aid of the 3D MR images. 3D MR imaging for surgical planning of superficial AVM is simple and noninvasive to perform, enhances intraoperative orientation, and is helpful for successful resection.

ACCELERATED FITTING OF STELLAR SPECTRA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ting, Yuan-Sen; Conroy, Charlie; Rix, Hans-Walter

2016-07-20

Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating amore » sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15–30 labels simultaneously.« less

The usage of image trigonometry in bone measurements.

PubMed

Dymond, Ian W; Ashforth, James A; Dymond, Graeme F; Spirakis, Thanos; Learmonth, Ian D

2013-01-01

The entire musculo-skeletal system responds dynamically to stresses and strains applied to it. Restoring normal biomechanics contributes to the normal function that ensures that physiological stresses and strains are preserved. Appropriate preoperative planning is mandatory to restore normal biomechanics at reconstructive surgery. Effective preoperative planning depends on the ability to reproducibly make accurate measurements of lengths and angles from plain radiographs. Measurement has become an integral part of orthopaedics to define morphological abnormality, to plan for reconstruction and for comparative research. The most prevalent method of measurement is usually based on lines drawn on radiographs with no accurate reference to the actual geometry of the structures. This two-dimensional projection of an asymmetrical three-dimensional structure leads to inaccuracy and consequently to a compromise in the overall precision of many procedures. In addition it is also difficult to monitor the progression of disease as the exact relationship of the bones and joints to each other, and to prosthetics, cannot be accurately recorded. This paper presents a method of digitally measuring relevant bone parameters in a geometric manner in order to achieve accurate, repeatable measurements.

One-dimensional simulation of stratification and dissolved oxygen in McCook Reservoir, Illinois

USGS Publications Warehouse

Robertson, Dale M.

2000-01-01

As part of the Chicagoland Underflow Plan/Tunnel and Reservoir Plan, the U.S. Army Corps of Engineers, Chicago District, plans to build McCook Reservoir.a flood-control reservoir to store combined stormwater and raw sewage (combined sewage). To prevent the combined sewage in the reservoir from becoming anoxic and producing hydrogen sulfide gas, a coarse-bubble aeration system will be designed and installed on the basis of results from CUP 0-D, a zero-dimensional model, and MAC3D, a three-dimensional model. Two inherent assumptions in the application of MAC3D are that density stratification in the simulated water body is minimal or not present and that surface heat transfers are unimportant and, therefore, may be neglected. To test these assumptions, the previously tested, one-dimensional Dynamic Lake Model (DLM) was used to simulate changes in temperature and dissolved oxygen in the reservoir after a 1-in-100-year event. Results from model simulations indicate that the assumptions made in MAC3D application are valid as long as the aeration system, with an air-flow rate of 1.2 cubic meters per second or more, is operated while the combined sewage is stored in the reservoir. Results also indicate that the high biochemical oxygen demand of the combined sewage will quickly consume the dissolved oxygen stored in the reservoir and the dissolved oxygen transferred through the surface of the reservoir; therefore, oxygen must be supplied by either the rising bubbles of the aeration system (a process not incorporated in DLM) or some other technique to prevent anoxia.

Teaching treatment planning for protons with educational open-source software: experience with FoCa and matRad.

PubMed

Sanchez-Parcerisa, Daniel; Udías, Jose

2018-05-12

Open-source, MATLAB-based treatment planning systems FoCa and matRAD were used in a pilot project for training prospective medical physicists and postgraduate physics students in treatment planning and beam modeling techniques for proton therapy. In the four exercises designed, students learnt how proton pencil beams are modeled and how dose is calculated in three-dimensional voxelized geometries, how pencil beam scanning plans (PBS) are constructed, the rationale behind the choice of spot spacing in patient plans, and the dosimetric differences between photon IMRT and proton PBS plans. Sixty students of two courses participated in the pilot project, with over 90% of satisfactory rating from student surveys. The pilot experience will certainly be continued. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

The use of 3D planning in facial surgery: preliminary observations.

PubMed

Hoarau, R; Zweifel, D; Simon, C; Broome, M

2014-12-01

Three-dimensional (3D) planning is becoming a more commonly used tool in maxillofacial surgery. At first used only virtually, 3D planning now also enables the creation of useful intraoperative aids such as cutting guides, which decrease the operative difficulty. In our center, we have used 3D planning in various domains of facial surgery and have investigated the advantages of this technique. We have also addressed the difficulties associated with its use. 3D planning increases the accuracy of reconstructive surgery, decreases operating time, whilst maintaining excellent esthetic results. However, its use is restricted to osseous reconstruction at this stage and once planning has been undertaken, it cannot be reversed or altered intraoperatively. Despite the attractive nature of this new tool, its uses and practicalities must be further evaluated. In particular, cost-effectiveness, hospital stay, and patient perceived benefits must be assessed. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Transcatheter Closure of Bilateral Multiple Huge Pulmonary Arteriovenous Malformations with Homemade Double-Umbrella Occluders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong Hongshan, E-mail: zhonghongshan@hotmail.com; Xu Ke; Shao Haibo

2008-07-15

A 28-year-old man underwent successful transcatheter occlusion of three huge pulmonary arteriovenous malformations (PAVMs) using homemade double-umbrella occluders and stainless steel coils. Thoracic CT with three-dimensional reconstruction and pulmonary angiography were used for treatment planning and follow-up. The diameters of the feeding vessels were 11 mm, 13 mm, and 14 mm, respectively. This report demonstrates the novel design and utility of the double-umbrella occluder, an alternative tool for treatment of large PAVMs.

NASA B737 flight test results of the total energy control system

NASA Technical Reports Server (NTRS)

Bruce, Kevin R.

1987-01-01

The Total Energy Control System (TECS) is an integrated autopilot/autothrottle developed by BCAC that was test flown on NASA Langley's Transport System Research Vehicle (i.e., a highly modified Boeing B737). This systems was developed using principles of total energy in which the total kinetic and potential energy of the airplane was controlled by the throttles, and the energy distribution controled by the elevator. TECS integrates all the control functions of a conventional pitch autopilot and autothrottle into a single generalized control concept. This integration provides decoupled flightpath and maneuver control, as well as a coordinated throttle response for all maneuvers. A mode hierarchy was established to preclude exceeding airplane safety and performance limits. The flight test of TECS took place as a series of five flights over a 33-week period during September 1985 at NASA Langley. Most of the original flight test plan was completed within the first three flights with the system not exhibiting any instabilities or design problems that required any gain adjustment during flight.

Role of Cone Beam Computed Tomography in Diagnosis and Treatment Planning in Dentistry: An Update.

PubMed

Shukla, Sagrika; Chug, Ashi; Afrashtehfar, Kelvin I

2017-11-01

Accurate diagnosis and treatment planning are the backbone of any medical therapy; for this reason, cone beam computed tomography (CBCT) was introduced and has been widely used. CBCT technology provides a three-dimensional image viewing, enabling exact location and extent of lesions or any anatomical region. For the very same reason, CBCT can not only be used for surgical fields but also for fields such as endodontics, prosthodontics, and orthodontics for appropriate treatment planning and effective dental care. The aim and clinical significance of this review are to update dental clinicians on the CBCT applications in each dental specialty for an appropriate diagnosis and more predictable treatment.

Rapid inverse planning for pressure-driven drug infusions in the brain.

PubMed

Rosenbluth, Kathryn H; Martin, Alastair J; Mittermeyer, Stephan; Eschermann, Jan; Dickinson, Peter J; Bankiewicz, Krystof S

2013-01-01

Infusing drugs directly into the brain is advantageous to oral or intravenous delivery for large molecules or drugs requiring high local concentrations with low off-target exposure. However, surgeons manually planning the cannula position for drug delivery in the brain face a challenging three-dimensional visualization task. This study presents an intuitive inverse-planning technique to identify the optimal placement that maximizes coverage of the target structure while minimizing the potential for leakage outside the target. The technique was retrospectively validated using intraoperative magnetic resonance imaging of infusions into the striatum of non-human primates and into a tumor in a canine model and applied prospectively to upcoming human clinical trials.

Key principles to improve programmes and interventions in complementary feeding.

PubMed

Lutter, Chessa K; Iannotti, Lora; Creed-Kanashiro, Hilary; Guyon, Agnes; Daelmans, Bernadette; Robert, Rebecca; Haider, Rukhsana

2013-09-01

Although there are some examples of successful complementary feeding programmes to promote healthy growth and prevent stunting at the community level, to date there are few, if any, examples of successful programmes at scale. A lack of systematic process and impact evaluations on pilot projects to generate lessons learned has precluded scaling up of effective programmes. Programmes to effect positive change in nutrition rarely follow systematic planning, implementation, and evaluation (PIE) processes to enhance effectiveness over the long term. As a result a set of programme-oriented key principles to promote healthy growth remains elusive. The purpose of this paper is to fill this gap by proposing a set of principles to improve programmes and interventions to promote healthy growth and development. Identifying such principles for programme success has three requirements: rethinking traditional paradigms used to promote improved infant and young child feeding; ensuring better linkages to delivery platforms; and, improving programming. Following the PIE model for programmes and learning from experiences from four relatively large-scale programmes described in this paper, 10 key principles are identified in the areas of programme planning, programme implementation, programme evaluation, and dissemination, replication, and scaling up. Nonetheless, numerous operational research questions remain, some of which are highlighted in this paper. © 2013 John Wiley & Sons Ltd.

4D CT-based Treatment Planning for Intensity-Modulated Radiation Therapy and Proton Therapy for Distal Esophagus Cancer

PubMed Central

Zhang, Xiaodong; Zhao, Kuai-Le; Guerrero, Thomas M.; McGuire, Sean E.; Yaremko, Brian; Komaki, Ritsuko; Cox, James D.; Hui, Zhouguang; Li, Yupeng; Newhauser, Wayne D.; Mohan, Radhe; Liao, Zhongxing

2008-01-01

Purpose To compare three-dimensional (3D) and 4D computed tomography (CT)– based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. Materials and Methods IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Results Compared with IMRT, median lung volumes exposed to 5,10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%,5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%,8.4%,5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index CI=1.99) and greater irradiation of the heart (heart-V40=41.8%) compared with the IMRT plan(CI=1.55, heart-V40=35.7%) or the three-beam proton plan (CI=1.46, heart-V40=27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas-filling. Conclusions Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses. PMID:18722278

Effective motion planning strategy for space robot capturing targets under consideration of the berth position

NASA Astrophysics Data System (ADS)

Zhang, Xin; Liu, Jinguo

2018-07-01

Although many motion planning strategies for missions involving space robots capturing floating targets can be found in the literature, relatively little has discussed how to select the berth position where the spacecraft base hovers. In fact, the berth position is a flexible and controllable factor, and selecting a suitable berth position has a great impact on improving the efficiency of motion planning in the capture mission. Therefore, to make full use of the manoeuvrability of the space robot, this paper proposes a new viewpoint that utilizes the base berth position as an optimizable parameter to formulate a more comprehensive and effective motion planning strategy. Considering the dynamic coupling, the dynamic singularities, and the physical limitations of space robots, a unified motion planning framework based on the forward kinematics and parameter optimization technique is developed to convert the planning problem into the parameter optimization problem. For getting rid of the strict grasping position constraints in the capture mission, a new conception of grasping area is proposed to greatly simplify the difficulty of the motion planning. Furthermore, by utilizing the penalty function method, a new concise objective function is constructed. Here, the intelligent algorithm, Particle Swarm Optimization (PSO), is worked as solver to determine the free parameters. Two capturing cases, i.e., capturing a two-dimensional (2D) planar target and capturing a three-dimensional (3D) spatial target, are studied under this framework. The corresponding simulation results demonstrate that the proposed method is more efficient and effective for planning the capture missions.

Three-dimensional model simulation and reconstruction of composite total maxillectomy defects with fibula osteomyocutaneous flap flow-through from radial forearm flap.

PubMed

He, Yue; Zhu, Han Guang; Zhang, Zhi Yuan; He, Jie; Sader, Robert

2009-12-01

A total maxillectomy always causes composite defects of maxilla, zygomatic bone, orbital floor or rim, and palatal and nasal mucosa lining. This leads to significant functional and cosmetic consequences after ablative surgery. The purpose of this clinical study was to preliminarily 3-dimensionally reconstruct the defect of total maxillectomy with sufficient bone support and soft tissue lining. Three-dimensional model simulation technique and free fibula osteomyocutaneous flap flow-through from radial forearm flap were used to reconstruct a total maxillectomy defect for a 21-year-old female patient. Preoperatively, the 3-dimensional (3D) simulated resin models of skeleton and fibula were used to design the osteotomies and bone segment replacement. At surgery, a 22-cm-length free fibula was divided into 4 segments to make 1 maxilla skeletal framework in the schedule of the preoperative model surgical planning with a radial forearm flap flow-through for the free fibula flap with skin paddle to repair the palatal and nasal region. Free fibula and radial forearm flap were alive, and the patient was satisfied with the results both esthetically and functionally after dental rehabilitation which was carried out 6 months after surgery. This preliminarily clinical study and case demonstrated that: the fibula osteomyocutaneous flap is an ideal donor site in 3D total maxillectomy defect reconstruction, because of its thickness, length, and bone uniformity which makes ideal support for dental rehabilitation; the flow-through forearm radial flap not only serves as the vascular bridge to midface reconstruction, but also provides sufficient soft tissue cover for the intraoral defect; and the 3D model simulation and preoperative surgical planning are effective methods to refine reconstruction surgery, shorten the surgical time, and predict the outcome after operation.

Variations of the superficial middle cerebral vein: classification using three-dimensional CT angiography.

PubMed

Suzuki, Y; Matsumoto, K

2000-05-01

Classification of variations of the superficial middle cerebral vein (SMCV) remains ambiguous. We propose a new classification system based on embryologic development for preoperative examination. Three-dimensional CT angiography was used to evaluate 500 SMCVs (in 250 patients). The outflow vessels from the SMCV were classified into seven types on the basis of embryologic development. The 3D CT angiograms in axial stereoscopic and oblique views and multiple intensity projection images were evaluated by the same neurosurgeon on two occasions. Inconsistent interpretations were regarded as equivocal. Three-dimensional CT angiography clearly depicted the SMCV running along the lesser wing or the middle cranial fossa. However, the outflow vessel could not be confirmed as the sphenoparietal, cavernous, or emissary type in 39 (8%) of the sides. SMCVs running in the middle cranial fossa to join the transverse sinus or superior petrosal sinus were accurately identified. SMCVs were present in 456 sides: 62% entered the sphenoparietal sinus or the cavernous sinus and 12% joined the emissary vein. Nine vessels were the superior petrosal type, 10 the basal type, 12 the squamosal type, and 44 the undeveloped type. Three-dimensional CT angiography can depict the vessels and their anatomic relationship to the bone structure, allowing identification of the SMCV variant in individual patients. Preoperative planning for skull base surgery requires such information to reduce the invasiveness of the procedure. With the use of our classification system, 3D CT angiography can provide exact and practical information concerning the SMCV.

Virtual planning in orthognathic surgery.

PubMed

Stokbro, K; Aagaard, E; Torkov, P; Bell, R B; Thygesen, T

2014-08-01

Numerous publications regarding virtual surgical planning protocols have been published, most reporting only one or two case reports to emphasize the hands-on planning. None have systematically reviewed the data published from clinical trials. This systematic review analyzes the precision and accuracy of three-dimensional (3D) virtual surgical planning of orthognathic procedures compared with the actual surgical outcome following orthognathic surgery reported in clinical trials. A systematic search of the current literature was conducted to identify clinical trials with a sample size of more than five patients, comparing the virtual surgical plan with the actual surgical outcome. Search terms revealed a total of 428 titles, out of which only seven articles were included, with a combined sample size of 149 patients. Data were presented in three different ways: intra-class correlation coefficient, 3D surface area with a difference <2mm, and linear and angular differences in three dimensions. Success criteria were set at 2mm mean difference in six articles; 125 of the 133 patients included in these articles were regarded as having had a successful outcome. Due to differences in the presentation of data, meta-analysis was not possible. Virtual planning appears to be an accurate and reproducible method for orthognathic treatment planning. A more uniform presentation of the data is necessary to allow the performance of a meta-analysis. Currently, the software system most often used for 3D virtual planning in clinical trials is SimPlant (Materialise). More independent clinical trials are needed to further validate the precision of virtual planning. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. All rights reserved.

Sampling and mapping forest volume and biomass using airborne LIDARs

Treesearch

Erik Naesset; Terje Gobakken; Ross Nelson

2009-01-01

Since around 1995, extensive research efforts have been made in Scandinavia to develop airborne Light Detection and Ranging (LIDAR) as an operational tool for wall-to-wall mapping of forest stands for planning purposes. Scanning LIDAR has the ability to capture the entire three-dimensional structure of forest canopies and has therefore proved to be a very efficient...

A national center for biocomputation: in search of a patient-specific interactive virtual surgery workbench

NASA Technical Reports Server (NTRS)

Ross, M. D.; Montgomery, K.; Linton, S.; Cheng, R.; Smith, J.

1998-01-01

This report describes the three-dimensional imaging and virtual environment technologies developed in NASA's Biocomputation Center for scientific purposes that have now led to applications in the field of medicine. A major goal is to develop a virtual environment surgery workbench for planning complex craniofacial and breast reconstructive surgery, and for training surgeons.

Turbulence modeling for hypersonic flight

NASA Technical Reports Server (NTRS)

Bardina, Jorge E.

1993-01-01

The objective of the proposed work is to continue to develop, verify, and incorporate the baseline two-equation turbulence models, which account for the effects of compressibility at high speeds, into a three-dimensional Reynolds averaged Navier-Stokes (RANS) code. Additionally, we plan to provide documented descriptions of the models and their numerical procedures so that they can be implemented into the NASP CFD codes.

Medical three-dimensional printing opens up new opportunities in cardiology and cardiac surgery.

PubMed

Bartel, Thomas; Rivard, Andrew; Jimenez, Alejandro; Mestres, Carlos A; Müller, Silvana

2018-04-14

Advanced percutaneous and surgical procedures in structural and congenital heart disease require precise pre-procedural planning and continuous quality control. Although current imaging modalities and post-processing software assists with peri-procedural guidance, their capabilities for spatial conceptualization remain limited in two- and three-dimensional representations. In contrast, 3D printing offers not only improved visualization for procedural planning, but provides substantial information on the accuracy of surgical reconstruction and device implantations. Peri-procedural 3D printing has the potential to set standards of quality assurance and individualized healthcare in cardiovascular medicine and surgery. Nowadays, a variety of clinical applications are available showing how accurate 3D computer reformatting and physical 3D printouts of native anatomy, embedded pathology, and implants are and how they may assist in the development of innovative therapies. Accurate imaging of pathology including target region for intervention, its anatomic features and spatial relation to the surrounding structures is critical for selecting optimal approach and evaluation of procedural results. This review describes clinical applications of 3D printing, outlines current limitations, and highlights future implications for quality control, advanced medical education and training.

A national facility for biological cryo-electron microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saibil, Helen R., E-mail: h.saibil@mail.cryst.bbk.ac.uk; Grünewald, Kay; Stuart, David I.

2015-01-01

This review provides a brief update on the use of cryo-electron microscopy for integrated structural biology, along with an overview of the plans for the UK national facility for electron microscopy being built at the Diamond synchrotron. Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided ofmore » the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback.« less

The relationship between three-dimensional imaging and group decision making: an exploratory study.

PubMed

Litynski, D M; Grabowski, M; Wallace, W A

1997-07-01

This paper describes an empirical investigation of the effect of three dimensional (3-D) imaging on group performance in a tactical planning task. The objective of the study is to examine the role that stereoscopic imaging can play in supporting face-to-face group problem solving and decision making-in particular, the alternative generation and evaluation processes in teams. It was hypothesized that with the stereoscopic display, group members would better visualize the information concerning the task environment, producing open communication and information exchanges. The experimental setting was a tactical command and control task, and the quality of the decisions and nature of the group decision process were investigated with three treatments: 1) noncomputerized, i.e., topographic maps with depth cues; 2) two-dimensional (2-D) imaging; and 3) stereoscopic imaging. The results were mixed on group performance. However, those groups with the stereoscopic displays generated more alternatives and spent less time on evaluation. In addition, the stereoscopic decision aid did not interfere with the group problem solving and decision-making processes. The paper concludes with a discussion of potential benefits, and the need to resolve demonstrated weaknesses of the technology.

In regard to "Tran A, Zhang J, Woods K, Yu V, Nguyen D, Gustafson G, Rosen L, Sheng K. Treatment planning comparison of IMPT, VMAT and 4π radiotherapy for prostate cases. Radiation oncology. 2017 Jan 11; 12(1):10".

PubMed

Sarkar, Biplab

2018-04-12

This article describe the three dimensional geometrical incompetency of the term "4π radiotherapy"; frequently used in radiation oncology to establish the superiority (or rather complexity) of particular kind of external beam delivery technique. It was claimed by several researchers, to obtain 4π c solid angle at target centre created by the tele-therapy delivery machine in three dimensional Euclidian space. However with the present design of linear accelerator (or any other tele-therapy machine) it is not possible to achieve more than 2π c with the allowed boundary condition of 0 ≤ Gnatry position≤π c and [Formula: see text]≤Couch Position≤[Formula: see text] .This article describes why it is not possible to achieve a 4π c solid angle at any point in three dimensional Euclidian spaces. This article also recommends not to use the terminology "4π radiotherapy" for describing any external beam technique or its complexity as this term is geometrically wrong.

Target coverage in image-guided stereotactic body radiotherapy of liver tumors.

PubMed

Wunderink, Wouter; Méndez Romero, Alejandra; Vásquez Osorio, Eliana M; de Boer, Hans C J; Brandwijk, René P; Levendag, Peter C; Heijmen, Ben J M

2007-05-01

To determine the effect of image-guided procedures (with computed tomography [CT] and electronic portal images before each treatment fraction) on target coverage in stereotactic body radiotherapy for liver patients using a stereotactic body frame (SBF) and abdominal compression. CT guidance was used to correct for day-to-day variations in the tumor's mean position in the SBF. By retrospectively evaluating 57 treatment sessions, tumor coverage, as obtained with the clinically applied CT-guided protocol, was compared with that of alternative procedures. The internal target volume-plus (ITV(+)) was introduced to explicitly include uncertainties in tumor delineations resulting from CT-imaging artifacts caused by residual respiratory motion. Tumor coverage was defined as the volume overlap of the ITV(+), derived from a tumor delineated in a treatment CT scan, and the planning target volume. Patient stability in the SBF, after acquisition of the treatment CT scan, was evaluated by measuring the displacement of the bony anatomy in the electronic portal images relative to CT. Application of our clinical protocol (with setup corrections following from manual measurements of the distances between the contours of the planning target volume and the daily clinical target volume in three orthogonal planes, multiple two-dimensional) increased the frequency of nearly full (> or = 99%) ITV(+) coverage to 77% compared with 63% without setup correction. An automated three-dimensional method further improved the frequency to 96%. Patient displacements in the SBF were generally small (< or = 2 mm, 1 standard deviation), but large craniocaudal displacements (maximal 7.2 mm) were occasionally observed. Daily, CT-assisted patient setup may substantially improve tumor coverage, especially with the automated three-dimensional procedure. In the present treatment design, patient stability in the SBF should be verified with portal imaging.

Respiratory gating and multifield technique radiotherapy for esophageal cancer.

PubMed

Ohta, Atsushi; Kaidu, Motoki; Tanabe, Satoshi; Utsunomiya, Satoru; Sasamoto, Ryuta; Maruyama, Katsuya; Tanaka, Kensuke; Saito, Hirotake; Nakano, Toshimichi; Shioi, Miki; Takahashi, Haruna; Kushima, Naotaka; Abe, Eisuke; Aoyama, Hidefumi

2017-03-01

To investigate the effects of a respiratory gating and multifield technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multifield technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans. In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V 5Gy , V 20Gy , mean dose with all three plans and the Heart V 25Gy -V 40Gy with Gating-2-field plan, V 35Gy , V 40Gy , mean dose with No Gating-4-field plan and V 30Gy -V 40Gy , and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. The lung parameters were reduced by the respiratory gating technique and increased by the multifield technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications.

Acute small bowel toxicity and preoperative chemoradiotherapy for rectal cancer: Investigating dose-volume relationships and role for inverse planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tho, Lye Mun; Glegg, Martin; Paterson, Jennifer

2006-10-01

Purpose: The relationship between volume of irradiated small bowel (VSB) and acute toxicity in rectal cancer radiotherapy is poorly quantified, particularly in patients receiving concurrent preoperative chemoradiotherapy. Using treatment planning data, we studied a series of such patients. Methods and Materials: Details of 41 patients with locally advanced rectal cancer were reviewed. All received 45 Gy in 25 fractions over 5 weeks, 3-4 fields three-dimensional conformal radiotherapy with daily 5-fluorouracil and folinic acid during Weeks 1 and 5. Toxicity was assessed prospectively in a weekly clinic. Using computed tomography planning software, the VSB was determined at 5 Gy dose intervalsmore » (V{sub 5}, V{sub 1}, etc.). Eight patients with maximal VSB had dosimetry and radiobiological modeling outcomes compared between inverse and conformal three-dimensional planning. Results: VSB correlated strongly with diarrheal severity at every dose level (p < 0.03), with strongest correlation at lowest doses. Median VSB differed significantly between patients experiencing Grade 0-1 and Grade 2-4 diarrhea (p {<=} 0.05). No correlation was found with anorexia, nausea, vomiting, abdominal cramps, age, body mass index, sex, tumor position, or number of fields. Analysis of 8 patients showed that inverse planning reduced median dose to small bowel by 5.1 Gy (p = 0.008) and calculated late normal tissue complication probability (NTCP) by 67% (p = 0.016). We constructed a model using mathematical analysis to predict for acute diarrhea occurring at V{sub 5} and V{sub 15}. Conclusions: A strong dose-volume relationship exists between VSB and acute diarrhea at all dose levels during preoperative chemoradiotherapy. Our constructed model may be useful in predicting toxicity, and this has been derived without the confounding influence of surgical excision on bowel function. Inverse planning can reduce calculated dose to small bowel and late NTCP, and its clinical role warrants further investigation.« less

Clinical Application of a Hybrid RapidArc Radiotherapy Technique for Locally Advanced Lung Cancer.

PubMed

Silva, Scott R; Surucu, Murat; Steber, Jennifer; Harkenrider, Matthew M; Choi, Mehee

2017-04-01

Radiation treatment planning for locally advanced lung cancer can be technically challenging, as delivery of ≥60 Gy to large volumes with concurrent chemotherapy is often associated with significant risk of normal tissue toxicity. We clinically implemented a novel hybrid RapidArc technique in patients with lung cancer and compared these plans with 3-dimensional conformal radiotherapy and RapidArc-only plans. Hybrid RapidArc was used to treat 11 patients with locally advanced lung cancer having bulky mediastinal adenopathy. All 11 patients received concurrent chemotherapy. All underwent a 4-dimensional computed tomography planning scan. Hybrid RapidArc plans concurrently combined static (60%) and RapidArc (40%) beams. All cases were replanned using 3- to 5-field 3-dimensional conformal radiotherapy and RapidArc technique as controls. Significant reductions in dose were observed in hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans for total lung V20 and mean (-2% and -0.6 Gy); contralateral lung mean (-2.92 Gy); and esophagus V60 and mean (-16.0% and -2.2 Gy; all P < .05). Contralateral lung doses were significantly lower for hybrid RapidArc plans compared to RapidArc-only plans (all P < .05). Compared to 3-dimensional conformal radiotherapy, heart V60 and mean dose were significantly improved with hybrid RapidArc (3% vs 5%, P = .04 and 16.32 Gy vs 16.65 Gy, P = .03). However, heart V40 and V45 and maximum spinal cord dose were significantly lower with RapidArc plans compared to hybrid RapidArc plans. Conformity and homogeneity were significantly better with hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans ( P < .05). Treatment was well tolerated, with no grade 3+ toxicities. To our knowledge, this is the first report on the clinical application of hybrid RapidArc in patients with locally advanced lung cancer. Hybrid RapidArc permitted safe delivery of 60 to 66 Gy to large lung tumors with concurrent chemotherapy and demonstrated advantages for reduction in low-dose lung volumes, esophageal dose, and mean heart dose.

Three-dimensional (3D) printing and its applications for aortic diseases.

PubMed

Hangge, Patrick; Pershad, Yash; Witting, Avery A; Albadawi, Hassan; Oklu, Rahmi

2018-04-01

Three-dimensional (3D) printing is a process which generates prototypes from virtual objects in computer-aided design (CAD) software. Since 3D printing enables the creation of customized objects, it is a rapidly expanding field in an age of personalized medicine. We discuss the use of 3D printing in surgical planning, training, and creation of devices for the treatment of aortic diseases. 3D printing can provide operators with a hands-on model to interact with complex anatomy, enable prototyping of devices for implantation based upon anatomy, or even provide pre-procedural simulation. Potential exists to expand upon current uses of 3D printing to create personalized implantable devices such as grafts. Future studies should aim to demonstrate the impact of 3D printing on outcomes to make this technology more accessible to patients with complex aortic diseases.

Dedicated Stereophotogrammetric X-Ray System For Craniofacial Research And Treatment Planning

NASA Astrophysics Data System (ADS)

Baumrind, Sheldon; Moffitt, Francis; Curry, Sean; Isaacson, Robert J.

1983-07-01

We have constructed and brought into use what we believe to be the first dedicated coplanar craniofacial stereometric x-ray system for clinical use. Paired Machlett Dynamax 50/58 x-ray tubes with 0.3 mm focal spots are employed. Displacement between emitters is 16 inches. The focus film distance for both emitters is 66.5 inches. The mid-sagittal plane to focus distance is 60 inches. One film of each stereo pair conforms with the standards of the Second Roentgenocephalometric Workshop and can be used to make all standard two-dimensional orthodontic and cephalometric measurements. When supplemented by data from the conjugate film, a three-dimensional coordinate map can be generated as a machine operation. Specialized complementary software has been developed to increase the reliability of landmark location both in two and in three dimensions.

Surgery-first approach using a three-dimensional virtual setup and surgical simulation for skeletal Class III correction

PubMed Central

Im, Joon; Kang, Sang Hoon; Lee, Ji Yeon; Kim, Moon Key

2014-01-01

A 19-year-old woman presented to our dental clinic with anterior crossbite and mandibular prognathism. She had a concave profile, long face, and Angle Class III molar relationship. She showed disharmony in the crowding of the maxillomandibular dentition and midline deviation. The diagnosis and treatment plan were established by a three-dimensional (3D) virtual setup and 3D surgical simulation, and a surgical wafer was produced using the stereolithography technique. No presurgical orthodontic treatment was performed. Using the surgery-first approach, Le Fort I maxillary osteotomy and mandibular bilateral intraoral vertical ramus osteotomy setback were carried out. Treatment was completed with postorthodontic treatment. Thus, symmetrical and balanced facial soft tissue and facial form as well as stabilized and well-balanced occlusion were achieved. PMID:25473649

Radio Frequency Ablation Registration, Segmentation, and Fusion Tool

PubMed Central

McCreedy, Evan S.; Cheng, Ruida; Hemler, Paul F.; Viswanathan, Anand; Wood, Bradford J.; McAuliffe, Matthew J.

2008-01-01

The Radio Frequency Ablation Segmentation Tool (RFAST) is a software application developed using NIH's Medical Image Processing Analysis and Visualization (MIPAV) API for the specific purpose of assisting physicians in the planning of radio frequency ablation (RFA) procedures. The RFAST application sequentially leads the physician through the steps necessary to register, fuse, segment, visualize and plan the RFA treatment. Three-dimensional volume visualization of the CT dataset with segmented 3D surface models enables the physician to interactively position the ablation probe to simulate burns and to semi-manually simulate sphere packing in an attempt to optimize probe placement. PMID:16871716

Comparison of heart and coronary artery doses associated with intensity-modulated radiotherapy versus three-dimensional conformal radiotherapy for distal esophageal cancer.

PubMed

Kole, Thomas P; Aghayere, Osarhieme; Kwah, Jason; Yorke, Ellen D; Goodman, Karyn A

2012-08-01

To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D-CRT. Long-term studies are necessary to determine how this will impact on development of coronary artery disease and other cardiac complications. Copyright © 2012 Elsevier Inc. All rights reserved.

Dosimetric comparison of standard three-dimensional conformal radiotherapy followed by intensity-modulated radiotherapy boost schedule (sequential IMRT plan) with simultaneous integrated boost–IMRT (SIB IMRT) treatment plan in patients with localized carcinoma prostate

PubMed Central

Bansal, A.; Kapoor, R.; Singh, S. K.; Kumar, N.; Oinam, A. S.; Sharma, S. C.

2012-01-01

Aims: Dosimeteric and radiobiological comparison of two radiation schedules in localized carcinoma prostate: Standard Three-Dimensional Conformal Radiotherapy (3DCRT) followed by Intensity Modulated Radiotherapy (IMRT) boost (sequential-IMRT) with Simultaneous Integrated Boost IMRT (SIB-IMRT). Material and Methods: Thirty patients were enrolled. In all, the target consisted of PTV P + SV (Prostate and seminal vesicles) and PTV LN (lymph nodes) where PTV refers to planning target volume and the critical structures included: bladder, rectum and small bowel. All patients were treated with sequential-IMRT plan, but for dosimetric comparison, SIB-IMRT plan was also created. The prescription dose to PTV P + SV was 74 Gy in both strategies but with different dose per fraction, however, the dose to PTV LN was 50 Gy delivered in 25 fractions over 5 weeks for sequential-IMRT and 54 Gy delivered in 27 fractions over 5.5 weeks for SIB-IMRT. The treatment plans were compared in terms of dose–volume histograms. Also, Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) obtained with the two plans were compared. Results: The volume of rectum receiving 70 Gy or more (V > 70 Gy) was reduced to 18.23% with SIB-IMRT from 22.81% with sequential-IMRT. SIB-IMRT reduced the mean doses to both bladder and rectum by 13% and 17%, respectively, as compared to sequential-IMRT. NTCP of 0.86 ± 0.75% and 0.01 ± 0.02% for the bladder, 5.87 ± 2.58% and 4.31 ± 2.61% for the rectum and 8.83 ± 7.08% and 8.25 ± 7.98% for the bowel was seen with sequential-IMRT and SIB-IMRT plans respectively. Conclusions: For equal PTV coverage, SIB-IMRT markedly reduced doses to critical structures, therefore should be considered as the strategy for dose escalation. SIB-IMRT achieves lesser NTCP than sequential-IMRT. PMID:23204659

Comparison of Three-Dimensional Planning-Assisted and Conventional Acetabular Cup Positioning in Total Hip Arthroplasty: A Randomized Controlled Trial.

PubMed

Sariali, Elhadi; Boukhelifa, Nadia; Catonne, Yves; Pascal Moussellard, Hugues

2016-01-20

Malpositioning of the acetabular cup during total hip arthroplasty increases the risk of dislocation, edge-loading, squeaking, early wear, and loosening. We hypothesized that the use of three-dimensional (3-D) visualization tools to identify the planned cup position relative to the acetabular edge intraoperatively would increase the accuracy of cup orientation. The purpose of this study was to compare 3-D planning-assisted implantation and freehand insertion of the acetabular cup. This was a prospective randomized controlled study of two groups of twenty-eight patients each. In the first group, cup positioning was guided by 3-D views of the cup within the acetabulum obtained during 3-D preoperative planning. In the control group, the cup was placed freehand. All of the patients were operated on by the same surgeon, through a minimally invasive direct anterior approach with the patient in the supine position. Cup anteversion and abduction angles were measured on 3-D computed tomography (CT) reconstructions. The main evaluation criterion was the percentage of outliers according to the Lewinnek safe zone. Operative time did not differ between the two groups. The cup anteversion was more accurate in the 3-D planning group (mean difference from the planned angle [and standard deviation], -2.7° ± 5.4°) compared with the freehand-placement group (6.6° ± 9.5°). According to the Lewinnek safe zone, overall, the percentage of outliers was lower in the 3-D planning group (21%; six patients) than in the control group (46%; thirteen patients). According to the Callanan safe zone, the percentage of outliers was also lower in the 3-D planning group (25% versus 64%). Although cup abduction was also restored with greater accuracy in the 3-D planning group, on the basis of the Lewinnek safe zone, the percentage of abduction outliers was comparable between groups, with fewer high-abduction values, but more low-abduction values, in the 3-D planning group. Preoperative 3-D planning increased the accuracy of anteversion restoration and reduced the percentage of outliers without increasing the operative time. In this study, the same advantage could not be demonstrated for abduction. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Multi-dimensional printing in thoracic surgery: current and future applications

PubMed Central

Kwok, Jackson K. S.; Lau, Rainbow W. H.; Zhao, Ze-Rui; Yu, Peter S. Y.; Ho, Jacky Y. K.; Chow, Simon C. Y.; Wan, Innes Y. P.

2018-01-01

Three-dimensional (3D) printing has been gaining much attention in the medical field in recent years. At present, 3D printing most commonly contributes in pre-operative surgical planning of complicated surgery. It is also utilized for producing personalized prosthesis, well demonstrated by the customized rib cage, vertebral body models and customized airway splints. With on-going research and development, it will likely play an increasingly important role across the surgical fields. This article reviews current application of 3D printing in thoracic surgery and also provides a brief overview on the extended and updated use of 3D printing in bioprinting and 4D printing. PMID:29732197

Resolving the theory of planned behaviour's 'expectancy-value muddle' using dimensional salience.

PubMed

Newton, Joshua D; Ewing, Michael T; Burney, Sue; Hay, Margaret

2012-01-01

The theory of planned behaviour is one of the most widely used models of decision-making in the health literature. Unfortunately, the primary method for assessing the theory's belief-based expectancy-value models results in statistically uninterpretable findings, giving rise to what has become known as the 'expectancy-value muddle'. Moreover, existing methods for resolving this muddle are associated with various conceptual or practical limitations. This study addresses these issues by identifying and evaluating a parsimonious method for resolving the expectancy-value muddle. Three hundred and nine Australian residents aged 18-24 years rated the expectancy and value of 18 beliefs about posthumous organ donation. Participants also nominated their five most salient beliefs using a dimensional salience approach. Salient beliefs were perceived as being more likely to eventuate than non-salient beliefs, indicating that salient beliefs could be used to signify the expectancy component. The expectancy-value term was therefore represented by summing the value ratings of salient beliefs, an approach that predicted attitude (adjusted R2 = 0.21) and intention (adjusted R2 = 0.21). These findings suggest that the dimensional salience approach is a useful method for overcoming the expectancy-value muddle in applied research settings.

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.

A novel representation for planning 3-D collision-free paths

NASA Technical Reports Server (NTRS)

Bonner, Susan; Kelley, Robert B.

1990-01-01

A new scheme for the representation of objects, the successive spherical approximation (SSA), facilitates the rapid planning of collision-free paths in a dynamic three-dimensional environment. The hierarchical nature of the SSA allows collisions to be determined efficiently while still providing an exact representation of objects. The rapidity with which collisions can be detected, less than 1 sec per environment object per path, makes it possible to use a generate-and-test path-planning strategy driven by human conceptual knowledge to determine collision-free paths in a matter of seconds on a Sun 3/180 computer. A hierarchy of rules, based on the concept of a free space cell, is used to find heuristically satisfying collision-free paths in a structured environment.

V/STOL wind-tunnel testing

NASA Technical Reports Server (NTRS)

Koenig, D. G.

1984-01-01

Factors influencing effective program planning for V/STOL wind-tunnel testing are discussed. The planning sequence itself, which includes a short checklist of considerations that could enhance the value of the tests, is also described. Each of the considerations, choice of wind tunnel, type of model installation, model development and test operations, is discussed, and examples of appropriate past and current V/STOL test programs are provided. A short survey of the moderate to large subsonic wind tunnels is followed by a review of several model installations, from two-dimensional to large-scale models of complete aircraft configurations. Model sizing, power simulation, and planning are treated, including three areas is test operations: data-acquisition systems, acoustic measurements in wind tunnels, and flow surveying.

Confocal Imaging of porous media

NASA Astrophysics Data System (ADS)

Shah, S.; Crawshaw, D.; Boek, D.

2012-12-01

Carbonate rocks, which hold approximately 50% of the world's oil and gas reserves, have a very complicated and heterogeneous structure in comparison with sandstone reservoir rock. We present advances with different techniques to image, reconstruct, and characterize statistically the micro-geometry of carbonate pores. The main goal here is to develop a technique to obtain two dimensional and three dimensional images using Confocal Laser Scanning Microscopy. CLSM is used in epi-fluorescent imaging mode, allowing for the very high optical resolution of features well below 1μm size. Images of pore structures were captured using CLSM imaging where spaces in the carbonate samples were impregnated with a fluorescent, dyed epoxy-resin, and scanned in the x-y plane by a laser probe. We discuss the sample preparation in detail for Confocal Imaging to obtain sub-micron resolution images of heterogeneous carbonate rocks. We also discuss the technical and practical aspects of this imaging technique, including its advantages and limitation. We present several examples of this application, including studying pore geometry in carbonates, characterizing sub-resolution porosity in two dimensional images. We then describe approaches to extract statistical information about porosity using image processing and spatial correlation function. We have managed to obtain very low depth information in z -axis (~ 50μm) to develop three dimensional images of carbonate rocks with the current capabilities and limitation of CLSM technique. Hence, we have planned a novel technique to obtain higher depth information to obtain high three dimensional images with sub-micron resolution possible in the lateral and axial planes.

Radar E-O image fusion

NASA Technical Reports Server (NTRS)

Oneil, William F.

1993-01-01

The fusion of radar and electro-optic (E-O) sensor images presents unique challenges. The two sensors measure different properties of the real three-dimensional (3-D) world. Forming the sensor outputs into a common format does not mask these differences. In this paper, the conditions under which fusion of the two sensor signals is possible are explored. The program currently planned to investigate this problem is briefly discussed.

Comparison of 3D Reconstructive Technologies Used for Morphometric Research and the Translation of Knowledge Using a Decision Matrix

ERIC Educational Resources Information Center

Martin, Charys M.; Roach, Victoria A.; Nguyen, Ngan; Rice, Charles L.; Wilson, Timothy D.

2013-01-01

The use of three-dimensional (3D) models for education, pre-operative assessment, presurgical planning, and measurement have become more prevalent. With the increase in prevalence of 3D models there has also been an increase in 3D reconstructive software programs that are used to create these models. These software programs differ in…

Positron emission tomography-guided conformal fast neutron therapy for glioblastoma multiforme

PubMed Central

Stelzer, Keith J.; Douglas, James G.; Mankoff, David A.; Silbergeld, Daniel L.; Krohn, Kenneth A.; Laramore, George E.; Spence, Alexander M.

2008-01-01

Glioblastoma multiforme (GBM) continues to be a difficult therapeutic challenge. Our study was conducted to determine whether improved survival and tumor control could be achieved with modern delivery of fast neutron radiation using three-dimensional treatment planning. Ten patients were enrolled. Eligibility criteria included pathologic diagnosis of GBM, age ≥ 18 years, and KPS ≥60. Patients underwent MRI and 18F-fluorodeoxyglucose PET (FDG PET) as part of initial three-dimensional treatment planning. Sequential targets were treated with noncoplanar fields to a total dose of 18 Gy in 16 fractions over 4 weeks. Median and 1-year overall survival were 55 weeks and 60%, respectively. One patient remains alive at last follow-up 255 weeks after diagnosis. Median progression-free survival was 16 weeks, and all patients had tumor progression by 39 weeks. Treatment was clinically well tolerated, but evidence of mild to moderate gliosis and microvascular sclerosis consistent with radiation injury was observed at autopsy in specimens taken from regions of contralateral brain that received approximately 6–10 Gy. Fast neutron radiation using modern imaging, treatment planning, and beam delivery was feasible to a total dose of 18 Gy, but tumor control probability was poor in comparison to that predicted from a dose-response model based on older studies. Steep dose-response curves for both tumor control and neurotoxicity continue to present a challenge to establishing a therapeutic window for fast neutron radiation in GBM, even with modern techniques. PMID:18055860

Stereoscopic virtual reality models for planning tumor resection in the sellar region.

PubMed

Wang, Shou-sen; Zhang, Shang-ming; Jing, Jun-jie

2012-11-28

It is difficult for neurosurgeons to perceive the complex three-dimensional anatomical relationships in the sellar region. To investigate the value of using a virtual reality system for planning resection of sellar region tumors. The study included 60 patients with sellar tumors. All patients underwent computed tomography angiography, MRI-T1W1, and contrast enhanced MRI-T1W1 image sequence scanning. The CT and MRI scanning data were collected and then imported into a Dextroscope imaging workstation, a virtual reality system that allows structures to be viewed stereoscopically. During preoperative assessment, typical images for each patient were chosen and printed out for use by the surgeons as references during surgery. All sellar tumor models clearly displayed bone, the internal carotid artery, circle of Willis and its branches, the optic nerve and chiasm, ventricular system, tumor, brain, soft tissue and adjacent structures. Depending on the location of the tumors, we simulated the transmononasal sphenoid sinus approach, transpterional approach, and other approaches. Eleven surgeons who used virtual reality models completed a survey questionnaire. Nine of the participants said that the virtual reality images were superior to other images but that other images needed to be used in combination with the virtual reality images. The three-dimensional virtual reality models were helpful for individualized planning of surgery in the sellar region. Virtual reality appears to be promising as a valuable tool for sellar region surgery in the future.

Motion processing with two eyes in three dimensions.

PubMed

Rokers, Bas; Czuba, Thaddeus B; Cormack, Lawrence K; Huk, Alexander C

2011-02-11

The movement of an object toward or away from the head is perhaps the most critical piece of information an organism can extract from its environment. Such 3D motion produces horizontally opposite motions on the two retinae. Little is known about how or where the visual system combines these two retinal motion signals, relative to the wealth of knowledge about the neural hierarchies involved in 2D motion processing and binocular vision. Canonical conceptions of primate visual processing assert that neurons early in the visual system combine monocular inputs into a single cyclopean stream (lacking eye-of-origin information) and extract 1D ("component") motions; later stages then extract 2D pattern motion from the cyclopean output of the earlier stage. Here, however, we show that 3D motion perception is in fact affected by the comparison of opposite 2D pattern motions between the two eyes. Three-dimensional motion sensitivity depends systematically on pattern motion direction when dichoptically viewing gratings and plaids-and a novel "dichoptic pseudoplaid" stimulus provides strong support for use of interocular pattern motion differences by precluding potential contributions from conventional disparity-based mechanisms. These results imply the existence of eye-of-origin information in later stages of motion processing and therefore motivate the incorporation of such eye-specific pattern-motion signals in models of motion processing and binocular integration.

Application of Rapid Prototyping Pelvic Model for Patients with DDH to Facilitate Arthroplasty Planning: A Pilot Study.

PubMed

Xu, Jie; Li, Deng; Ma, Ruo-fan; Barden, Bertram; Ding, Yue

2015-11-01

Total hip arthroplasty (THA) is challenging in cases of osteoarthritis secondary to developmental dysplasia of the hip (DDH). Acetabular deficiency makes the positioning of the acetabular component difficult. Computer tomography based, patient-individual three dimensional (3-D) rapid prototype technology (RPT)-models were used to plan the placement of acetabular cup so that a surgeon was able to identify pelvic structures, assess the ideal extent of reaming and determine the size of cup after a reconstructive procedure. Intraclass correlation coefficients (ICCs) were used to analyze the agreement between the sizes of chosen components on the basis of preoperative planning and the actual sizes used in the operation. The use of the 3-D RPT-model facilitates the surgical procedures due to better planning and improved orientation. Copyright © 2015 Elsevier Inc. All rights reserved.

Diagnostic ability of computed tomography using DentaScan software in endodontics: case reports.

PubMed

Siotia, Jaya; Gupta, Sunil K; Acharya, Shashi R; Saraswathi, Vidya

2011-01-01

Radiographic examination is essential in diagnosis and treatment planning in endodontics. Conventional radiographs depict structures in two dimensions only. The ability to assess the area of interest in three dimensions is advantageous. Computed tomography is an imaging technique which produces three-dimensional images of an object by taking a series of two-dimensional sectional X-ray images. DentaScan is a computed tomography software program that allows the mandible and maxilla to be imaged in three planes: axial, panoramic, and cross-sectional. As computed tomography is used in endodontics, DentaScan can play a wider role in endodontic diagnosis. It provides valuable information in the assessment of the morphology of the root canal, diagnosis of root fractures, internal and external resorptions, pre-operative assessment of anatomic structures etc. The aim of this article is to explore the clinical usefulness of computed tomography and DentaScan in endodontic diagnosis, through a series of four cases of different endodontic problems.

Three-Dimensional Image Fusion of 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography and Contrast-Enhanced Computed Tomography for Computer-Assisted Planning of Maxillectomy of Recurrent Maxillary Squamous Cell Carcinoma and Defect Reconstruction.

PubMed

Yu, Yao; Zhang, Wen-Bo; Liu, Xiao-Jing; Guo, Chuan-Bin; Yu, Guang-Yan; Peng, Xin

2017-06-01

The purpose of this study was to describe new technology assisted by 3-dimensional (3D) image fusion of 18 F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT (CECT) for computer planning of a maxillectomy of recurrent maxillary squamous cell carcinoma and defect reconstruction. Treatment of recurrent maxillary squamous cell carcinoma usually includes tumor resection and free flap reconstruction. FDG-PET/CT provided images of regions of abnormal glucose uptake and thus showed metabolic tumor volume to guide tumor resection. CECT data were used to create 3D reconstructed images of vessels to show the vascular diameters and locations, so that the most suitable vein and artery could be selected during anastomosis of the free flap. The data from preoperative maxillofacial CECT scans and FDG-PET/CT imaging were imported into the navigation system (iPlan 3.0; Brainlab, Feldkirchen, Germany). Three-dimensional image fusion between FDG-PET/CT and CECT was accomplished using Brainlab software according to the position of the 2 skulls simulated in the CECT image and PET/CT image, respectively. After verification of the image fusion accuracy, the 3D reconstruction images of the metabolic tumor, vessels, and other critical structures could be visualized within the same coordinate system. These sagittal, coronal, axial, and 3D reconstruction images were used to determine the virtual osteotomy sites and reconstruction plan, which was provided to the surgeon and used for surgical navigation. The average shift of the 3D image fusion between FDG-PET/CT and CECT was less than 1 mm. This technique, by clearly showing the metabolic tumor volume and the most suitable vessels for anastomosis, facilitated resection and reconstruction of recurrent maxillary squamous cell carcinoma. We used 3D image fusion of FDG-PET/CT and CECT to successfully accomplish resection and reconstruction of recurrent maxillary squamous cell carcinoma. This method has the potential to improve the clinical outcomes of these challenging procedures. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Virtual Diagnostic Interface: Aerospace Experimentation in the Synthetic Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; McCrea, Andrew C.

2009-01-01

The Virtual Diagnostics Interface (ViDI) methodology combines two-dimensional image processing and three-dimensional computer modeling to provide comprehensive in-situ visualizations commonly utilized for in-depth planning of wind tunnel and flight testing, real time data visualization of experimental data, and unique merging of experimental and computational data sets in both real-time and post-test analysis. The preparation of such visualizations encompasses the realm of interactive three-dimensional environments, traditional and state of the art image processing techniques, database management and development of toolsets with user friendly graphical user interfaces. ViDI has been under development at the NASA Langley Research Center for over 15 years, and has a long track record of providing unique and insightful solutions to a wide variety of experimental testing techniques and validation of computational simulations. This report will address the various aspects of ViDI and how it has been applied to test programs as varied as NASCAR race car testing in NASA wind tunnels to real-time operations concerning Space Shuttle aerodynamic flight testing. In addition, future trends and applications will be outlined in the paper.

Virtual Diagnostic Interface: Aerospace Experimentation in the Synthetic Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; McCrea, Andrew C.

2010-01-01

The Virtual Diagnostics Interface (ViDI) methodology combines two-dimensional image processing and three-dimensional computer modeling to provide comprehensive in-situ visualizations commonly utilized for in-depth planning of wind tunnel and flight testing, real time data visualization of experimental data, and unique merging of experimental and computational data sets in both real-time and post-test analysis. The preparation of such visualizations encompasses the realm of interactive three-dimensional environments, traditional and state of the art image processing techniques, database management and development of toolsets with user friendly graphical user interfaces. ViDI has been under development at the NASA Langley Research Center for over 15 years, and has a long track record of providing unique and insightful solutions to a wide variety of experimental testing techniques and validation of computational simulations. This report will address the various aspects of ViDI and how it has been applied to test programs as varied as NASCAR race car testing in NASA wind tunnels to real-time operations concerning Space Shuttle aerodynamic flight testing. In addition, future trends and applications will be outlined in the paper.

Visions of visualization aids: Design philosophy and experimental results

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.

1990-01-01

Aids for the visualization of high-dimensional scientific or other data must be designed. Simply casting multidimensional data into a two- or three-dimensional spatial metaphor does not guarantee that the presentation will provide insight or parsimonious description of the phenomena underlying the data. Indeed, the communication of the essential meaning of some multidimensional data may be obscured by presentation in a spatially distributed format. Useful visualization is generally based on pre-existing theoretical beliefs concerning the underlying phenomena which guide selection and formatting of the plotted variables. Two examples from chaotic dynamics are used to illustrate how a visulaization may be an aid to insight. Two examples of displays to aid spatial maneuvering are described. The first, a perspective format for a commercial air traffic display, illustrates how geometric distortion may be introduced to insure that an operator can understand a depicted three-dimensional situation. The second, a display for planning small spacecraft maneuvers, illustrates how the complex counterintuitive character of orbital maneuvering may be made more tractable by removing higher-order nonlinear control dynamics, and allowing independent satisfaction of velocity and plume impingement constraints on orbital changes.

Structural and congenital heart disease interventions: the role of three-dimensional printing.

PubMed

Meier, L M; Meineri, M; Qua Hiansen, J; Horlick, E M

2017-02-01

Advances in catheter-based interventions in structural and congenital heart disease have mandated an increased demand for three-dimensional (3D) visualisation of complex cardiac anatomy. Despite progress in 3D imaging modalities, the pre- and periprocedural visualisation of spatial anatomy is relegated to two-dimensional flat screen representations. 3D printing is an evolving technology based on the concept of additive manufacturing, where computerised digital surface renders are converted into physical models. Printed models replicate complex structures in tangible forms that cardiovascular physicians and surgeons can use for education, preprocedural planning and device testing. In this review we discuss the different steps of the 3D printing process, which include image acquisition, segmentation, printing methods and materials. We also examine the expanded applications of 3D printing in the catheter-based treatment of adult patients with structural and congenital heart disease while highlighting the current limitations of this technology in terms of segmentation, model accuracy and dynamic capabilities. Furthermore, we provide information on the resources needed to establish a hospital-based 3D printing laboratory.

Evolution of lower hybrid turbulence in the ionosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganguli, G.; Crabtree, C.; Mithaiwala, M.

2015-11-15

Three-dimensional evolution of the lower hybrid turbulence driven by a spatially localized ion ring beam perpendicular to the ambient magnetic field in space plasmas is analyzed. It is shown that the quasi-linear saturation model breaks down when the nonlinear rate of scattering by thermal electron is larger than linear damping rates, which can occur even for low wave amplitudes. The evolution is found to be essentially a three-dimensional phenomenon, which cannot be accurately explained by two-dimensional simulations. An important feature missed in previous studies of this phenomenon is the nonlinear conversion of electrostatic lower hybrid waves into electromagnetic whistler andmore » magnetosonic waves and the consequent energy loss due to radiation from the source region. This can result in unique low-amplitude saturation with extended saturation time. It is shown that when the nonlinear effects are considered the net energy that can be permanently extracted from the ring beam is larger. The results are applied to anticipate the outcome of a planned experiment that will seed lower hybrid turbulence in the ionosphere and monitor its evolution.« less

Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiography in treatment planning for arteriovenous malformation radiosurgery.

PubMed

Bednarz, G; Downes, B; Werner-Wasik, M; Rosenwasser, R H

2000-03-15

This study was initiated to evaluate the advantages of using three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), as an adjuvant to conventional stereotactic angiography, in obtaining three-dimensional information about an arteriovenous malformation (AVM) nidus and in optimizing radiosurgical treatment plans. Following angiography, contrast-enhanced MRI and MRA studies were obtained in 22 consecutive patients undergoing Gamma Knife radiosurgery for AVM. A treatment plan was designed, based on the angiograms and modified as necessary, using the information provided by MRA. The quantitative analysis involved calculation of the ratio of the treated volume to the MRA nidus volume (the tissue volume ratio [TVR]) for the initial and final treatment plans. In 12 cases (55%), the initial treatment plans were modified after including the MRA information in the treatment planning process. The mean TVR for the angiogram-based plans was 1.63 (range 1.17-2.17). The mean coverage of the MRA nidus by the angiogram-based plans was 93% (range 73-99%). The mean MRA nidus volume was 2.4 cc (range 0. 6-5.3 cc). The MRA-based modifications resulted in increased conformity with the mean TVR of 1.46 (range 1.20-1.74). These modifications were caused by MRA revealing irregular nidi and/or vascular components superimposed on the angiographic projections of the nidi. In a number of cases, the information from MRA was essential in defining the nidus when the projections of the angiographic outlines showed different superior and/or inferior extent of the nidus. In two cases, MRA revealed irregular nidi, correlating well with the angiograms and showed that the angiographically acceptable plans undertreated 27% of the MRA nidus in one case and 18% of the nidus in the other case. In the remaining 10 cases (45%), both MRI and MRA failed to detect the nidus due to surgical clip artifacts and the presence of embolizing glue. The 3D TOF MRA provided information on irregular AVM shape, which was not visualized by angiography alone, and it was superior to MRI for defining the AVM nidus. However, when imaging artifacts obscured the AVM nidus on MRI and MRA, angiography permitted detection of AVM. Utilizing MRA as a complementary imaging modality to angiography increased accuracy of the AVM radiosurgery and allowed for optimal dose planning.

The Magnetohydrodynamic Kelvin-Helmholtz Instability: A Three-dimensional Study of Nonlinear Evolution

NASA Astrophysics Data System (ADS)

Ryu, Dongsu; Jones, T. W.; Frank, Adam

2000-12-01

We investigate through high-resolution three-dimensional simulations the nonlinear evolution of compressible magnetohydrodynamic flows subject to the Kelvin-Helmholtz instability. As in our earlier work, we have considered periodic sections of flows that contain a thin, transonic shear layer but are otherwise uniform. The initially uniform magnetic field is parallel to the shear plane but oblique to the flow itself. We confirm in three-dimensional flows the conclusion from our two-dimensional work that even apparently weak magnetic fields embedded in Kelvin-Helmholtz unstable plasma flows can be fundamentally important to nonlinear evolution of the instability. In fact, that statement is strengthened in three dimensions by this work because it shows how field-line bundles can be stretched and twisted in three dimensions as the quasi-two-dimensional Cat's Eye vortex forms out of the hydrodynamical motions. In our simulations twisting of the field may increase the maximum field strength by more than a factor of 2 over the two-dimensional effect. If, by these developments, the Alfvén Mach number of flows around the Cat's Eye drops to unity or less, our simulations suggest that magnetic stresses will eventually destroy the Cat's Eye and cause the plasma flow to self-organize into a relatively smooth and apparently stable flow that retains memory of the original shear. For our flow configurations, the regime in three dimensions for such reorganization is 4<~MAx<~50, expressed in terms of the Alfvén Mach number of the original velocity transition and the initial Alfvén speed projected to the flow plan. When the initial field is stronger than this, the flow either is linearly stable (if MAx<~2) or becomes stabilized by enhanced magnetic tension as a result of the corrugated field along the shear layer before the Cat's Eye forms (if MAx>~2). For weaker fields the instability remains essentially hydrodynamic in early stages, and the Cat's Eye is destroyed by the hydrodynamic secondary instabilities of a three-dimensional nature. Then, the flows evolve into chaotic structures that approach decaying isotropic turbulence. In this stage, there is considerable enhancement to the magnetic energy due to stretching, twisting, and turbulent amplification, which is retained long afterward. The magnetic energy eventually catches up to the kinetic energy, and the nature of flows becomes magnetohydrodynamic. Decay of the magnetohydrodynamic turbulence is enhanced by dissipation accompanying magnetic reconnection. Hence, in three dimensions as in two dimensions, very weak fields do not modify substantially the character of the flow evolution but do increase global dissipation rates.

Plane-Based Sampling for Ray Casting Algorithm in Sequential Medical Images

PubMed Central

Lin, Lili; Chen, Shengyong; Shao, Yan; Gu, Zichun

2013-01-01

This paper proposes a plane-based sampling method to improve the traditional Ray Casting Algorithm (RCA) for the fast reconstruction of a three-dimensional biomedical model from sequential images. In the novel method, the optical properties of all sampling points depend on the intersection points when a ray travels through an equidistant parallel plan cluster of the volume dataset. The results show that the method improves the rendering speed at over three times compared with the conventional algorithm and the image quality is well guaranteed. PMID:23424608

Applications Of Digital Image Acquisition In Anthropometry

NASA Astrophysics Data System (ADS)

Woolford, Barbara; Lewis, James L.

1981-10-01

Anthropometric data on reach and mobility have traditionally been collected by time consuming and relatively inaccurate manual methods. Three dimensional digital image acquisition promises to radically increase the speed and ease of data collection and analysis. A three-camera video anthropometric system for collecting position, velocity, and force data in real time is under development for the Anthropometric Measurement Laboratory at NASA's Johnson Space Center. The use of a prototype of this system for collecting data on reach capabilities and on lateral stability is described. Two extensions of this system are planned.

Kinematic state estimation and motion planning for stochastic nonholonomic systems using the exponential map.

PubMed

Park, Wooram; Liu, Yan; Zhou, Yu; Moses, Matthew; Chirikjian, Gregory S

2008-04-11

A nonholonomic system subjected to external noise from the environment, or internal noise in its own actuators, will evolve in a stochastic manner described by an ensemble of trajectories. This ensemble of trajectories is equivalent to the solution of a Fokker-Planck equation that typically evolves on a Lie group. If the most likely state of such a system is to be estimated, and plans for subsequent motions from the current state are to be made so as to move the system to a desired state with high probability, then modeling how the probability density of the system evolves is critical. Methods for solving Fokker-Planck equations that evolve on Lie groups then become important. Such equations can be solved using the operational properties of group Fourier transforms in which irreducible unitary representation (IUR) matrices play a critical role. Therefore, we develop a simple approach for the numerical approximation of all the IUR matrices for two of the groups of most interest in robotics: the rotation group in three-dimensional space, SO(3), and the Euclidean motion group of the plane, SE(2). This approach uses the exponential mapping from the Lie algebras of these groups, and takes advantage of the sparse nature of the Lie algebra representation matrices. Other techniques for density estimation on groups are also explored. The computed densities are applied in the context of probabilistic path planning for kinematic cart in the plane and flexible needle steering in three-dimensional space. In these examples the injection of artificial noise into the computational models (rather than noise in the actual physical systems) serves as a tool to search the configuration spaces and plan paths. Finally, we illustrate how density estimation problems arise in the characterization of physical noise in orientational sensors such as gyroscopes.

On-line estimations of delivered radiation doses in three-dimensional conformal radiotherapy treatments of carcinoma uterine cervix patients in linear accelerator

PubMed Central

Putha, Suman Kumar; Saxena, P. U.; Banerjee, S.; Srinivas, Challapalli; Vadhiraja, B. M.; Ravichandran, Ramamoorthy; Joan, Mary; Pai, K. Dinesh

2016-01-01

Transmission of radiation fluence through patient's body has a correlation to the planned target dose. A method to estimate the delivered dose to target volumes was standardized using a beam level 0.6 cc ionization chamber (IC) positioned at electronic portal imaging device (EPID) plane from the measured transit signal (St) in patients with cancer of uterine cervix treated with three-dimensional conformal radiotherapy (3DCRT). The IC with buildup cap was mounted on linear accelerator EPID frame with fixed source to chamber distance of 146.3 cm, using a locally fabricated mount. Sts were obtained for different water phantom thicknesses and radiation field sizes which were then used to generate a calibration table against calculated midplane doses at isocenter (Diso,TPS), derived from the treatment planning system. A code was developed using MATLAB software which was used to estimate the in vivo dose at isocenter (Diso,Transit) from the measured Sts. A locally fabricated pelvic phantom validated the estimations of Diso,Transit before implementing this method on actual patients. On-line dose estimations were made (3 times during treatment for each patient) in 24 patients. The Diso,Transit agreement with Diso,TPS in phantom was within 1.7% and the mean percentage deviation with standard deviation is −1.37% ±2.03% (n = 72) observed in patients. Estimated in vivo dose at isocenter with this method provides a good agreement with planned ones which can be implemented as part of quality assurance in pelvic sites treated with simple techniques, for example, 3DCRT where there is a need for documentation of planned dose delivery. PMID:28144114

On-line estimations of delivered radiation doses in three-dimensional conformal radiotherapy treatments of carcinoma uterine cervix patients in linear accelerator.

PubMed

Putha, Suman Kumar; Saxena, P U; Banerjee, S; Srinivas, Challapalli; Vadhiraja, B M; Ravichandran, Ramamoorthy; Joan, Mary; Pai, K Dinesh

2016-01-01

Transmission of radiation fluence through patient's body has a correlation to the planned target dose. A method to estimate the delivered dose to target volumes was standardized using a beam level 0.6 cc ionization chamber (IC) positioned at electronic portal imaging device (EPID) plane from the measured transit signal (S t ) in patients with cancer of uterine cervix treated with three-dimensional conformal radiotherapy (3DCRT). The IC with buildup cap was mounted on linear accelerator EPID frame with fixed source to chamber distance of 146.3 cm, using a locally fabricated mount. S t s were obtained for different water phantom thicknesses and radiation field sizes which were then used to generate a calibration table against calculated midplane doses at isocenter (D iso,TPS ), derived from the treatment planning system. A code was developed using MATLAB software which was used to estimate the in vivo dose at isocenter (D iso,Transit ) from the measured S t s. A locally fabricated pelvic phantom validated the estimations of D iso,Transit before implementing this method on actual patients. On-line dose estimations were made (3 times during treatment for each patient) in 24 patients. The D iso,Transit agreement with D iso,TPS in phantom was within 1.7% and the mean percentage deviation with standard deviation is -1.37% ±2.03% ( n = 72) observed in patients. Estimated in vivo dose at isocenter with this method provides a good agreement with planned ones which can be implemented as part of quality assurance in pelvic sites treated with simple techniques, for example, 3DCRT where there is a need for documentation of planned dose delivery.

Three-dimensional imaging, an important factor of decision in breast augmentation.

PubMed

de Runz, A; Boccara, D; Bertheuil, N; Claudot, F; Brix, M; Simon, E

2018-04-01

Since the beginning of the 21st century, three-dimensional imaging systems have been used more often in plastic surgery, especially during preoperative planning for breast surgery and to simulate the postoperative appearance of the implant in the patient's body. The main objective of this study is to assess the patients' attitudes regarding 3D simulation for breast augmentation. A study was conducted, which included women who were operated on for primary breast augmentation. During the consultation, a three-dimensional simulation with Crisalix was done and different sized implants were fitted in the bra. Thirty-eight women were included. The median age was 29.4, and the median prosthesis volume was 310mL. The median rank given regarding the final result was 9 (IQR: 8-9). Ninety percent of patients agreed (66% absolutely agreed, and 24% partially agreed) that the final product after breast augmentations was similar to the Crisalix simulation. Ninety-three percent of the patients believed that the three-dimensional simulation helped them choose their prosthesis (61% a lot and 32% a little). After envisaging a breast enlargement, patients estimated that the Crisalix system was absolutely necessary (21%), very useful (32%), useful (45%), or unnecessary (3%). Regarding prosthesis choice, an equal number of women preferred the 3D simulation (19 patients) as preferred using different sizes of implants in the bra (19 patients). The present study demonstrated that 3D simulation is actually useful for patients in order to envisage a breast augmentation. But it should be used as a complement to the classic method of trying different sized breast implants in the bra. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Three-dimensional venous visualization with phase-lag computed tomography angiography for reconstructive microsurgery.

PubMed

Sakakibara, Shunsuke; Onishi, Hiroyuki; Hashikawa, Kazunobu; Akashi, Masaya; Sakakibara, Akiko; Nomura, Tadashi; Terashi, Hiroto

2015-05-01

Most free flap reconstruction complications involve vascular compromise. Evaluation of vascular anatomy provides considerable information that can potentially minimize these complications. Previous reports have shown that contrast-enhanced computed tomography is effective for understanding three-dimensional arterial anatomy. However, most vascular complications result from venous thromboses, making imaging of venous anatomy highly desirable. The phase-lag computed tomography angiography (pl-CTA) technique involves 64-channel (virtually, 128-channel) multidetector CT and is used to acquire arterial images using conventional CTA. Venous images are three-dimensionally reconstructed using a subtraction technique involving combined venous phase and arterial phase images, using a computer workstation. This technique was used to examine 48 patients (12 lower leg reconstructions, 34 head and neck reconstructions, and 2 upper extremity reconstructions) without complications. The pl-CTA technique can be used for three-dimensional visualization of peripheral veins measuring approximately 1 mm in diameter. The pl-CTA information was especially helpful for secondary free flap reconstructions in the head and neck region after malignant tumor recurrence. In such cases, radical dissection of the neck was performed as part of the first operation, and many vessels, including veins, were resected and used in the first free-tissue transfer. The pl-CTA images also allowed visualization of varicose changes in the lower leg region and helped us avoid selecting those vessels for anastomosis. Thus, the pl-CTA-derived venous anatomy information was useful for exact evaluations during the planning of free-tissue transfers. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Abdominal tumours in children: 3-D visualisation and surgical planning.

PubMed

Günther, P; Schenk, J P; Wunsch, R; Tröger, J; Waag, K L

2004-10-01

Solid abdominal tumours are of special importance in the field of paediatric surgery. Because of the dangers of cumulative irradiation and improved delineation of soft parts MRI is usually employed in children for diagnostic assessment. Compiling the radiologic information for surgical planning is often difficult by conventional methods. Newly improved and efficient 3-D volume rendering software is now available for visual reconstruction of tumour anatomy utilising segmentation and other special techniques. Because the intraoperative complication rate is close to 20 % as described in the literature, optimal preoperative visualisation and planning would seem imperative. All children with solid abdominal tumours at Heidelberg University in the year 2002 were included in this study. MR examinations were performed with a 0.5 Tesla magnet using a standard protocol. All MR data were processed with VG Studio Max 1.1, converting the two-dimensional data into three-dimensional data. This report presents 15 cases using this special technique: 7 with abdominal neuroblastoma, 6 with nephroblastoma, 1 ganglioneuroma, and 1 ovarian teratoma. Our experience shows that a better understanding of the surgical anatomy, particularly regarding the surrounding organs and vasculature, can be helpful in decreasing the incidence of inadvertent intraoperative injuries to these structures.

Practical approaches to four-dimensional heavy-charged-particle lung therapy.

PubMed

Mori, Shinichiro; Wu, Ziji; Folkert, Michael R; Kumagai, Motoki; Dobashi, Suguru; Sugane, Toshio; Baba, Masayuki

2010-01-01

We have developed new design algorithms for compensating boli to facilitate the implementation of four-dimensional charged-particle lung therapy in clinical applications. Four-dimensional CT (4DCT) data for eight lung cancer patients were acquired with a 16-slice CT under free breathing. Six compensating boli were developed that may be categorized into three classes: (1) boli-based on contoured gross tumor volumes (GTV) from a 4DCT data set during each respiratory phase, subsequently combined into one (GTV-4DCT bolus); (2) boli-based on contoured internal target volume (ITV) from image-processed 3DCT data only [temporal-maximum-intensity-projection (TMIP)/temporal-average-intensity-projection (TAIP)] with calculated boli (ITV-TMIP and ITV-TAIP boli); and (3) boli-based on contoured ITV utilizing image-processed 3DCT data, applied to 4DCT for design of boli for each phase, which were then combined. The carbon beam dose distribution within each bolus was calculated as a function of time and compared to plans in which respiratory-ungated/gated strategies were used. The GTV-4DCT treatment plan required a prohibitively long time for contouring the GTV manually for each respiratory phase, but it delivered more than 95% of the prescribed dose to the target volume. The TMIP and TAIP treatments, although more time-efficient, resulted in an unacceptable excess dose to normal tissues and underdosing of the target volume. The dose distribution for the ITV-4DCT bolus was similar to that for the GTV-4DCT bolus and required significantly less practitioner time. The ITV-4DCT bolus treatment plan is time-efficient and provides a high-quality dose distribution, making it a practical alternative to the GTV-4DCT bolus treatment plan.

Form and function of the human and chimpanzee forefoot: implications for early hominin bipedalism.

PubMed

Fernández, Peter J; Holowka, Nicholas B; Demes, Brigitte; Jungers, William L

2016-07-28

During bipedal walking, modern humans dorsiflex their forefoot at the metatarsophalangeal joints (MTPJs) prior to push off, which tightens the plantar soft tissues to convert the foot into a stiff propulsive lever. Particular features of metatarsal head morphology such as "dorsal doming" are thought to facilitate this stiffening mechanism. In contrast, chimpanzees are believed to possess MTPJ morphology that precludes high dorsiflexion excursions during terrestrial locomotion. The morphological affinity of the metatarsal heads has been used to reconstruct locomotor behavior in fossil hominins, but few studies have provided detailed empirical data to validate the assumed link between morphology and function at the MTPJs. Using three-dimensional kinematic and morphometric analyses, we show that humans push off with greater peak dorsiflexion angles at all MTPJs than do chimpanzees during bipedal and quadrupedal walking, with the greatest disparity occurring at MTPJ 1. Among MTPJs 2-5, both species exhibit decreasing peak angles from medial to lateral. This kinematic pattern is mirrored in the morphometric analyses of metatarsal head shape. Analyses of Australopithecus afarensis metatarsals reveal morphology intermediate between humans and chimpanzees, suggesting that this species used different bipedal push-off kinematics than modern humans, perhaps resulting in a less efficient form of bipedalism.

Modeling susceptibility difference artifacts produced by metallic implants in magnetic resonance imaging with point-based thin-plate spline image registration.

PubMed

Pauchard, Y; Smith, M; Mintchev, M

2004-01-01

Magnetic resonance imaging (MRI) suffers from geometric distortions arising from various sources. One such source are the non-linearities associated with the presence of metallic implants, which can profoundly distort the obtained images. These non-linearities result in pixel shifts and intensity changes in the vicinity of the implant, often precluding any meaningful assessment of the entire image. This paper presents a method for correcting these distortions based on non-rigid image registration techniques. Two images from a modelled three-dimensional (3D) grid phantom were subjected to point-based thin-plate spline registration. The reference image (without distortions) was obtained from a grid model including a spherical implant, and the corresponding test image containing the distortions was obtained using previously reported technique for spatial modelling of magnetic susceptibility artifacts. After identifying the nonrecoverable area in the distorted image, the calculated spline model was able to quantitatively account for the distortions, thus facilitating their compensation. Upon the completion of the compensation procedure, the non-recoverable area was removed from the reference image and the latter was compared to the compensated image. Quantitative assessment of the goodness of the proposed compensation technique is presented.

SU-F-T-500: The Effectiveness of a Patient Specific Bolus Made by Using Three-Dimensional Printing Technique in Photon Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujimoto, K; Yuasa, Y; Shiinoki, T

Purpose: A commercially available bolus (commercial-bolus) would not completely contact with the irregular shape of a patient’s skin. The purposes of this study were to customize a patient specific three-dimensional (3D) bolus using a 3D printer (3D-bolus) and to evaluate its clinical feasibility for photon radiotherapy. Methods: The 3D-bolus was designed using a treatment planning system (TPS) in DICOM-RT format. To print the 3D bolus, the file was converted into stereolithography format. To evaluate its physical characteristics, plans were created for water equivalent phantoms without the bolus, with the 3D-bolus printed in a flat form, and with the virtual bolusmore » which supposed a commercial-bolus. These plans were compared with the percent depth dose (PDD) measured from the TPS. Furthermore, to evaluate its clinical feasibility, the treatment plans were created for RANDO phantoms without the bolus and with the 3D-bolus which was customized for contacting with the surface of the phantom. Both plans were compared with the dose volume histogram (DVH) of the target volume. Results: In the physical evaluation, dmax of the plan without the bolus, with the 3D-bolus, and with the virtual bolus were 2.2 cm, 1.6 cm, and 1.7 cm, respectively. In the evaluation of clinical feasibility, for the plan without the bolus, Dmax, Dmin, Dmean, D90%, and V90% of the target volume were 102.6 %, 1.6 %, 88.8 %, 57.2 %, and 69.3 %, respectively. By using the 3D-bolus, the prescription dose could be delivered to at least 90 % of the target volume, Dmax, Dmin, Dmean, D90%, and V90% of the target volume were 104.3 %, 91.6 %, 92.1 %, 91.7 %, and 98.0 %, respectively. The 3D-bolus has the potential to be useful for providing effective dose coverage in the buildup region. Conclusion: A 3D-bolus produced using 3D printing technique is comparable to a commercially available bolus.« less

Applications of three-dimensional printing technology in urological practice.

PubMed

Youssef, Ramy F; Spradling, Kyle; Yoon, Renai; Dolan, Benjamin; Chamberlin, Joshua; Okhunov, Zhamshid; Clayman, Ralph; Landman, Jaime

2015-11-01

A rapid expansion in the medical applications of three-dimensional (3D)-printing technology has been seen in recent years. This technology is capable of manufacturing low-cost and customisable surgical devices, 3D models for use in preoperative planning and surgical education, and fabricated biomaterials. While several studies have suggested 3D printers may be a useful and cost-effective tool in urological practice, few studies are available that clearly demonstrate the clinical benefit of 3D-printed materials. Nevertheless, 3D-printing technology continues to advance rapidly and promises to play an increasingly larger role in the field of urology. Herein, we review the current urological applications of 3D printing and discuss the potential impact of 3D-printing technology on the future of urological practice. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

Web-based Three-dimensional Virtual Body Structures: W3D-VBS

PubMed Central

Temkin, Bharti; Acosta, Eric; Hatfield, Paul; Onal, Erhan; Tong, Alex

2002-01-01

Major efforts are being made to improve the teaching of human anatomy to foster cognition of visuospatial relationships. The Visible Human Project of the National Library of Medicine makes it possible to create virtual reality-based applications for teaching anatomy. Integration of traditional cadaver and illustration-based methods with Internet-based simulations brings us closer to this goal. Web-based three-dimensional Virtual Body Structures (W3D-VBS) is a next-generation immersive anatomical training system for teaching human anatomy over the Internet. It uses Visible Human data to dynamically explore, select, extract, visualize, manipulate, and stereoscopically palpate realistic virtual body structures with a haptic device. Tracking user’s progress through evaluation tools helps customize lesson plans. A self-guided “virtual tour” of the whole body allows investigation of labeled virtual dissections repetitively, at any time and place a user requires it. PMID:12223495

Web-based three-dimensional Virtual Body Structures: W3D-VBS.

PubMed

Temkin, Bharti; Acosta, Eric; Hatfield, Paul; Onal, Erhan; Tong, Alex

2002-01-01

Major efforts are being made to improve the teaching of human anatomy to foster cognition of visuospatial relationships. The Visible Human Project of the National Library of Medicine makes it possible to create virtual reality-based applications for teaching anatomy. Integration of traditional cadaver and illustration-based methods with Internet-based simulations brings us closer to this goal. Web-based three-dimensional Virtual Body Structures (W3D-VBS) is a next-generation immersive anatomical training system for teaching human anatomy over the Internet. It uses Visible Human data to dynamically explore, select, extract, visualize, manipulate, and stereoscopically palpate realistic virtual body structures with a haptic device. Tracking user's progress through evaluation tools helps customize lesson plans. A self-guided "virtual tour" of the whole body allows investigation of labeled virtual dissections repetitively, at any time and place a user requires it.

Utilization of the Internet to deliver educational materials to healthcare professionals.

PubMed

Hallgren, R C; Gorbis, S

1997-01-01

We have developed a computer-based learning module which uses three-dimensional animation sequences to enhance the acquisition of physical concepts and skills necessary for clinical evaluation and treatment of the cervical spine. This teaching tool, designed to serve as an adjunct to teaching strategies that faculty may be currently using, is available to students through the Kobiljak Resource Center at Michigan State University College of Osteopathic Medicine (MSUCOM) and via the Internet (http:/(/)hal.bim.msu.edu/EdTech) to individuals and groups who are physically removed from the MSU campus. While we are restricting this initial effort to the upper cervical spine, it is planned that future materials will include other parts of the body and, in addition, will enable students to not only visualize the effects of pathology on motion mechanics, but also give them the ability to interactively control an articulation in three-dimensional space.

Faceted Visualization of Three Dimensional Neuroanatomy By Combining Ontology with Faceted Search

PubMed Central

Veeraraghavan, Harini; Miller, James V.

2013-01-01

In this work, we present a faceted-search based approach for visualization of anatomy by combining a three dimensional digital atlas with an anatomy ontology. Specifically, our approach provides a drill-down search interface that exposes the relevant pieces of information (obtained by searching the ontology) for a user query. Hence, the user can produce visualizations starting with minimally specified queries. Furthermore, by automatically translating the user queries into the controlled terminology our approach eliminates the need for the user to use controlled terminology. We demonstrate the scalability of our approach using an abdominal atlas and the same ontology. We implemented our visualization tool on the opensource 3D Slicer software. We present results of our visualization approach by combining a modified Foundational Model of Anatomy (FMA) ontology with the Surgical Planning Laboratory (SPL) Brain 3D digital atlas, and geometric models specific to patients computed using the SPL brain tumor dataset. PMID:24006207

Faceted visualization of three dimensional neuroanatomy by combining ontology with faceted search.

PubMed

Veeraraghavan, Harini; Miller, James V

2014-04-01

In this work, we present a faceted-search based approach for visualization of anatomy by combining a three dimensional digital atlas with an anatomy ontology. Specifically, our approach provides a drill-down search interface that exposes the relevant pieces of information (obtained by searching the ontology) for a user query. Hence, the user can produce visualizations starting with minimally specified queries. Furthermore, by automatically translating the user queries into the controlled terminology our approach eliminates the need for the user to use controlled terminology. We demonstrate the scalability of our approach using an abdominal atlas and the same ontology. We implemented our visualization tool on the opensource 3D Slicer software. We present results of our visualization approach by combining a modified Foundational Model of Anatomy (FMA) ontology with the Surgical Planning Laboratory (SPL) Brain 3D digital atlas, and geometric models specific to patients computed using the SPL brain tumor dataset.

A Review of Current Clinical Applications of Three-Dimensional Printing in Spine Surgery

PubMed Central

Job, Alan Varkey; Chen, Jing; Baek, Jung Hwan

2018-01-01

Three-dimensional (3D) printing is a transformative technology with a potentially wide range of applications in the field of orthopaedic spine surgery. This article aims to review the current applications, limitations, and future developments of 3D printing technology in orthopaedic spine surgery. Current preoperative applications of 3D printing include construction of complex 3D anatomic models for improved visual understanding, preoperative surgical planning, and surgical simulations for resident education. Intraoperatively, 3D printers have been successfully used in surgical guidance systems and in the creation of patient specific implantable devices. Furthermore, 3D printing is revolutionizing the field of regenerative medicine and tissue engineering, allowing construction of biocompatible scaffolds suitable for cell growth and vasculature. Advances in printing technology and evidence of positive clinical outcomes are needed before there is an expansion of 3D printing applied to the clinical setting. PMID:29503698

A Review of Current Clinical Applications of Three-Dimensional Printing in Spine Surgery.

PubMed

Cho, Woojin; Job, Alan Varkey; Chen, Jing; Baek, Jung Hwan

2018-02-01

Three-dimensional (3D) printing is a transformative technology with a potentially wide range of applications in the field of orthopaedic spine surgery. This article aims to review the current applications, limitations, and future developments of 3D printing technology in orthopaedic spine surgery. Current preoperative applications of 3D printing include construction of complex 3D anatomic models for improved visual understanding, preoperative surgical planning, and surgical simulations for resident education. Intraoperatively, 3D printers have been successfully used in surgical guidance systems and in the creation of patient specific implantable devices. Furthermore, 3D printing is revolutionizing the field of regenerative medicine and tissue engineering, allowing construction of biocompatible scaffolds suitable for cell growth and vasculature. Advances in printing technology and evidence of positive clinical outcomes are needed before there is an expansion of 3D printing applied to the clinical setting.

Three-dimensional (3D) printing and its applications for aortic diseases

PubMed Central

Hangge, Patrick; Pershad, Yash; Witting, Avery A.; Albadawi, Hassan

2018-01-01

Three-dimensional (3D) printing is a process which generates prototypes from virtual objects in computer-aided design (CAD) software. Since 3D printing enables the creation of customized objects, it is a rapidly expanding field in an age of personalized medicine. We discuss the use of 3D printing in surgical planning, training, and creation of devices for the treatment of aortic diseases. 3D printing can provide operators with a hands-on model to interact with complex anatomy, enable prototyping of devices for implantation based upon anatomy, or even provide pre-procedural simulation. Potential exists to expand upon current uses of 3D printing to create personalized implantable devices such as grafts. Future studies should aim to demonstrate the impact of 3D printing on outcomes to make this technology more accessible to patients with complex aortic diseases. PMID:29850416

Three-Dimensional Integrated Survey for Building Investigations.

PubMed

Costantino, Domenica; Angelini, Maria Giuseppa

2015-11-01

The study shows the results of a survey aimed to represent a building collapse and the feasibility of the modellation as a support of structure analysis. An integrated survey using topographic, photogrammetric, and terrestrial laser techniques was carried out to obtain a three-dimensional (3D) model of the building, plans and prospects, and the particulars of the collapsed area. Authors acquired, by a photogrammetric survey, information about regular parties of the structure; while using laser scanner data they reconstructed a set of more interesting architectural details and areas with higher surface curvature. Specifically, the process of texture provided a detailed 3D structure of the areas under investigation. The analysis of the data acquired resulted to be very useful both in identifying the causes of the disaster and also in helping the reconstruction of the collapsed corner showing the contribution that the integrated surveys can give in preserving architectural and historic heritage. © 2015 American Academy of Forensic Sciences.

Three-dimensional Cross-Platform Planning for Complex Spinal Procedures: A New Method Adaptive to Different Navigation Systems.

PubMed

Kosterhon, Michael; Gutenberg, Angelika; Kantelhardt, Sven R; Conrad, Jens; Nimer Amr, Amr; Gawehn, Joachim; Giese, Alf

2017-08-01

A feasibility study. To develop a method based on the DICOM standard which transfers complex 3-dimensional (3D) trajectories and objects from external planning software to any navigation system for planning and intraoperative guidance of complex spinal procedures. There have been many reports about navigation systems with embedded planning solutions but only few on how to transfer planning data generated in external software. Patients computerized tomography and/or magnetic resonance volume data sets of the affected spinal segments were imported to Amira software, reconstructed to 3D images and fused with magnetic resonance data for soft-tissue visualization, resulting in a virtual patient model. Objects needed for surgical plans or surgical procedures such as trajectories, implants or surgical instruments were either digitally constructed or computerized tomography scanned and virtually positioned within the 3D model as required. As crucial step of this method these objects were fused with the patient's original diagnostic image data, resulting in a single DICOM sequence, containing all preplanned information necessary for the operation. By this step it was possible to import complex surgical plans into any navigation system. We applied this method not only to intraoperatively adjustable implants and objects under experimental settings, but also planned and successfully performed surgical procedures, such as the percutaneous lateral approach to the lumbar spine following preplanned trajectories and a thoracic tumor resection including intervertebral body replacement using an optical navigation system. To demonstrate the versatility and compatibility of the method with an entirely different navigation system, virtually preplanned lumbar transpedicular screw placement was performed with a robotic guidance system. The presented method not only allows virtual planning of complex surgical procedures, but to export objects and surgical plans to any navigation or guidance system able to read DICOM data sets, expanding the possibilities of embedded planning software.

Low dimensional temporal organization of spontaneous eye blinks in adults with developmental disabilities and stereotyped movement disorder.

PubMed

Lee, Mei-Hua; Bodfish, James W; Lewis, Mark H; Newell, Karl M

2010-01-01

This study investigated the mean rate and time-dependent sequential organization of spontaneous eye blinks in adults with intellectual and developmental disability (IDD) and individuals from this group who were additionally categorized with stereotypic movement disorder (IDD+SMD). The mean blink rate was lower in the IDD+SMD group than the IDD group and both of these groups had a lower blink rate than a contrast group of healthy adults. In the IDD group the n to n+1 sequential organization over time of the eye-blink durations showed a stronger compensatory organization than the contrast group suggesting decreased complexity/dimensionality of eye-blink behavior. Very low blink rate (and thus insufficient time series data) precluded analysis of time-dependent sequential properties in the IDD+SMD group. These findings support the hypothesis that both IDD and SMD are associated with a reduction in the dimension and adaptability of movement behavior and that this may serve as a risk factor for the expression of abnormal movements.

Technical Note: PRESAGE three-dimensional dosimetry accurately measures Gamma Knife output factors

PubMed Central

Klawikowski, Slade J.; Yang, James N.; Adamovics, John; Ibbott, Geoffrey S.

2014-01-01

Small-field output factor measurements are traditionally very difficult because of steep dose gradients, loss of lateral electronic equilibrium, and dose volume averaging in finitely sized detectors. Three-dimensional (3D) dosimetry is ideal for measuring small output factors and avoids many of these potential challenges of point and two-dimensional detectors. PRESAGE 3D polymer dosimeters were used to measure the output factors for the 4 mm and 8 mm collimators of the Leksell Perfexion Gamma Knife radiosurgery treatment system. Discrepancies between the planned and measured distance between shot centers were also investigated. A Gamma Knife head frame was mounted onto an anthropomorphic head phantom. Special inserts were machined to hold 60 mm diameter, 70 mm tall cylindrical PRESAGE dosimeters. The phantom was irradiated with one 16 mm shot and either one 4 mm or one 8 mm shot, to a prescribed dose of either 3 Gy or 4 Gy to the 50% isodose line. The two shots were spaced between 30 mm and 60 mm apart and aligned along the central axis of the cylinder. The Presage dosimeters were measured using the DMOS-RPC optical CT scanning system. Five independent 4 mm output factor measurements fell within 2% of the manufacturer’s Monte Carlo simulation-derived nominal value, as did two independent 8 mm output factor measurements. The measured distances between shot centers varied by ± 0.8 mm with respect to the planned shot displacements. On the basis of these results, we conclude that PRESAGE dosimetry is excellently suited to quantify the difficult-to-measure Gamma Knife output factors. PMID:25368961

Mission Operations of the Mars Exploration Rovers

NASA Technical Reports Server (NTRS)

Bass, Deborah; Lauback, Sharon; Mishkin, Andrew; Limonadi, Daniel

2007-01-01

A document describes a system of processes involved in planning, commanding, and monitoring operations of the rovers Spirit and Opportunity of the Mars Exploration Rover mission. The system is designed to minimize command turnaround time, given that inherent uncertainties in terrain conditions and in successful completion of planned landed spacecraft motions preclude planning of some spacecraft activities until the results of prior activities are known by the ground-based operations team. The processes are partitioned into those (designated as tactical) that must be tied to the Martian clock and those (designated strategic) that can, without loss, be completed in a more leisurely fashion. The tactical processes include assessment of downlinked data, refinement and validation of activity plans, sequencing of commands, and integration and validation of sequences. Strategic processes include communications planning and generation of long-term activity plans. The primary benefit of this partition is to enable the tactical portion of the team to focus solely on tasks that contribute directly to meeting the deadlines for commanding the rover s each sol (1 sol = 1 Martian day) - achieving a turnaround time of 18 hours or less, while facilitating strategic team interactions with other organizations that do not work on a Mars time schedule.

Final closure plan for the high-explosives open burn treatment facility at Lawrence Livermore National Laboratory Experimental Test Site 300

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathews, S.

This document addresses the interim status closure of the HE Open Bum Treatment Facility, as detailed by Title 22, Division 4.5, Chapter 15, Article 7 of the Califonia Code of Regulations (CCR) and by Title 40, Code of Federal Regulations (CFR) Part 265, Subpart G, ``Closure and Post Closure.`` The Closure Plan (Chapter 1) and the Post- Closure Plan (Chapter 2) address the concept of long-term hazard elimination. The Closure Plan provides for capping and grading the HE Open Bum Treatment Facility and revegetating the immediate area in accordance with applicable requirements. The Closure Plan also reflects careful consideration ofmore » site location and topography, geologic and hydrologic factors, climate, cover characteristics, type and amount of wastes, and the potential for contaminant migration. The Post-Closure Plan is designed to allow LLNL to monitor the movement, if any, of pollutants from the treatment area. In addition, quarterly inspections will ensure that all surfaces of the closed facility, including the cover and diversion ditches, remain in good repair, thus precluding the potential for contaminant migration.« less

Toxicity and dosimetric analysis of non-small cell lung cancer patients undergoing radiotherapy with 4DCT and image-guided intensity modulated radiotherapy: a regional centre's experience.

PubMed

Livingston, Gareth C; Last, Andrew J; Shakespeare, Thomas P; Dwyer, Patrick M; Westhuyzen, Justin; McKay, Michael J; Connors, Lisa; Leader, Stephanie; Greenham, Stuart

2016-09-01

For patients receiving radiotherapy for locally advance non-small cell lung cancer (NSCLC), the probability of experiencing severe radiation pneumonitis (RP) appears to rise with an increase in radiation received by the lungs. Intensity modulated radiotherapy (IMRT) provides the ability to reduce planned doses to healthy organs at risk (OAR) and can potentially reduce treatment-related side effects. This study reports toxicity outcomes and provides a dosimetric comparison with three-dimensional conformal radiotherapy (3DCRT). Thirty curative NSCLC patients received radiotherapy using four-dimensional computed tomography and five-field IMRT. All were assessed for early and late toxicity using common terminology criteria for adverse events. All plans were subsequently re-planned using 3DCRT to the same standard as the clinical plans. Dosimetric parameters for lungs, oesophagus, heart and conformity were recorded for comparison between the two techniques. IMRT plans achieved improved high-dose conformity and reduced OAR doses including lung volumes irradiated to 5-20 Gy. One case each of oesophagitis and erythema (3%) were the only Grade 3 toxicities. Rates of Grade 2 oesophagitis were 40%. No cases of Grade 3 RP were recorded and Grade 2 RP rates were as low as 3%. IMRT provides a dosimetric benefit when compared to 3DCRT. While the clinical benefit appears to increase with increasing target size and increasing complexity, IMRT appears preferential to 3DCRT in the treatment of NSCLC.

Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: incremental value over the two-dimensional technique.

PubMed

Pothineni, Koteswara R; Duncan, Kurt; Yelamanchili, Pridhvi; Nanda, Navin C; Patel, Vinod; Fan, PoHoey; Burri, Manjula V; Singh, Anurag; Panwar, Sadik R

2007-05-01

Twenty-nine patients with different tricuspid valve (TV) pathologies were studied by both two-dimensional transthoracic (2DTTE) and live/real time three-dimensional transthoracic echocardiography (3DTTE). A major contribution of 3DTTE over 2DTTE was the en face visualization of all three leaflets of the TV in all patients. This allowed accurate assessment of TV orifice area in patients with TV stenosis and carcinoid disease. Loss of TV leaflet tissue, defects in TV leaflets and size of TV systolic non-coaptation could also be delineated and resulted in identifying the mechanism of tricuspid regurgitation (TR) in patients with Ebstein's anomaly and rheumatic heart disease. Prolapse of TV leaflets could also be well visualized and enabled us to develop a schema for systematic assessment of individual segment prolapse which could help in surgical planning. The exact sites of chordae rupture in patients with flail TV as well as right ventricular papillary muscle rupture could be well seen by 3DTTE. 3DTTE also permitted sectioning of various TV masses for more specific diagnosis of their nature. In addition, color Doppler 3DTTE provided an estimate of quantitative evaluation of TR severity, since the exact shape and size of the vena contracta could be accurately assessed. In conclusion, our preliminary experience with 3DTTE has demonstrated substantial incremental value over 2DTTE in the assessment of various TV pathologies.

A Mode of Combined ERP and KMS Knowledge Management System Construction

NASA Astrophysics Data System (ADS)

Yuena, Kang; Yangeng, Wen; Qun, Zhou

The core of ERP and knowledge management is quite similar; both will send appropriate knowledge (goods, funds) to the right people (position) at the right time. It is reasonable to believe that increase the knowledge management system in ERP will help companies achieve their goals better. This paper compares the concept of logical point of hall three-dimensional structure of the knowledge management system and the ERP in methodology level. And found they are very similar in the time dimension, logic dimension and knowledge dimension. This laid the basis of methodology in the simultaneous planning, implementation and applications. And then proposed a knowledge-based ERP Multi-Agent Management System Model. Finally, the paper described the process from planning to implementation of knowledge management ERP system with multi-Agent interaction and impact from three concepts, management thinking, software and system.

Role of cardiac imaging and three-dimensional printing in percutaneous appendage closure.

PubMed

Iriart, Xavier; Ciobotaru, Vlad; Martin, Claire; Cochet, Hubert; Jalal, Zakaria; Thambo, Jean-Benoit; Quessard, Astrid

2018-06-06

Atrial fibrillation is the most frequent cardiac arrhythmia, affecting up to 13% of people aged>80 years, and is responsible for 15-20% of all ischaemic strokes. Left atrial appendage occlusion devices have been developed as an alternative approach to reduce the risk of stroke in patients for whom oral anticoagulation is contraindicated. The procedure can be technically demanding, and obtaining a complete left atrial appendage occlusion can be challenging. These observations have emphasized the importance of preprocedural planning, to optimize the accuracy and safety of the procedure. In this setting, a multimodality imaging approach, including three-dimensional imaging, is often used for preoperative assessment and procedural guidance. These imaging modalities, including transoesophageal echocardiography and multislice computed tomography, allow acquisition of a three-dimensional dataset that improves understanding of the cardiac anatomy; dedicated postprocessing software integrated into the clinical workflow can be used to generate a stereolithography file, which can be printed in a rubber-like material, seeking to replicate the myocardial tissue characteristics and mechanical properties of the left atrial appendage wall. The role of multimodality imaging and 3D printing technology offers a new field for implantation simulation, which may have a major impact on physician training and technique optimization. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Foundations of Effective Influence Operations: A Framework for Enhancing Army Capabilities

DTIC Science & Technology

2009-01-01

interesting approaches we came across in our survey of social science approaches that might be suitable for supporting influence operations. In many...planning, conducting, and assessing the impact of influence operations on attitudes and behaviors. The approach is based on survey instruments that...second to latitude. Influencing Individuals 21 To illustrate, Figure 2.1 presents, in a three-dimensional form, the results from a Galileo survey

Three-dimensional reduction and finite element analysis improves the treatment of pelvic malunion reconstructive surgery

PubMed Central

Kurz, Sascha; Pieroh, Philipp; Lenk, Maximilian; Josten, Christoph; Böhme, Jörg

2017-01-01

Abstract Rationale: Pelvic malunion is a rare complication and is technically challenging to correct owing to the complex three-dimensional (3D) geometry of the pelvic girdle. Hence, precise preoperative planning is required to ensure appropriate correction. Reconstructive surgery is generally a 2- or 3-stage procedure, with transiliac osteotomy serving as an alternative to address limb length discrepancy. Patient concerns: A 38-year-old female patient with a Mears type IV pelvic malunion with previous failed reconstructive surgery was admitted to our department due to progressive immobilization, increasing pain especially at the posterior pelvic arch and a leg length discrepancy. The leg discrepancy was approximately 4 cm and rotation of the right hip joint was associated with pain. Diagnosis: Radiography and computer tomography (CT) revealed a hypertrophic malunion at the site of the previous posterior osteotomy (Mears type IV) involving the anterior and middle column, according to the 3-column concept, as well as malunion of the left anterior arch (Mears type IV). Interventions: The surgery was planned virtually via 3D reconstruction, using the patient's CT, and subsequently performed via transiliac osteotomy and symphysiotomy. Finite element method (FEM) was used to plan the osteotomy and osteosynthesis as to include an estimation of the risk of implant failure. Outcomes: There was not incidence of neurological injury or infection, and the remaining leg length discrepancy was ≤ 2 cm. The patient recovered independent, pain free, mobility. Virtual 3D planning provided a more precise measurement of correction parameters than radiographic-based measurements. FEM analysis identified the highest risk for implant failure at the symphyseal plate osteosynthesis and the parasymphyseal screws. No implant failure was observed. Lessons: Transiliac osteotomy, with additional osteotomy or symphysiotomy, was a suitable surgical procedure for the correction of pelvic malunion and provided adequate correction of leg length discrepancy. Virtual 3D planning enabled precise determination of correction parameters, with FEM analysis providing an appropriate method to predict areas of implant failure. PMID:29049196

Surgical planning for radical prostatectomies using three-dimensional visualization and a virtual reality display system

NASA Astrophysics Data System (ADS)

Kay, Paul A.; Robb, Richard A.; King, Bernard F.; Myers, R. P.; Camp, Jon J.

1995-04-01

Thousands of radical prostatectomies for prostate cancer are performed each year. Radical prostatectomy is a challenging procedure due to anatomical variability and the adjacency of critical structures, including the external urinary sphincter and neurovascular bundles that subserve erectile function. Because of this, there are significant risks of urinary incontinence and impotence following this procedure. Preoperative interaction with three-dimensional visualization of the important anatomical structures might allow the surgeon to understand important individual anatomical relationships of patients. Such understanding might decrease the rate of morbidities, especially for surgeons in training. Patient specific anatomic data can be obtained from preoperative 3D MRI diagnostic imaging examinations of the prostate gland utilizing endorectal coils and phased array multicoils. The volumes of the important structures can then be segmented using interactive image editing tools and then displayed using 3-D surface rendering algorithms on standard work stations. Anatomic relationships can be visualized using surface displays and 3-D colorwash and transparency to allow internal visualization of hidden structures. Preoperatively a surgeon and radiologist can interactively manipulate the 3-D visualizations. Important anatomical relationships can better be visualized and used to plan the surgery. Postoperatively the 3-D displays can be compared to actual surgical experience and pathologic data. Patients can then be followed to assess the incidence of morbidities. More advanced approaches to visualize these anatomical structures in support of surgical planning will be implemented on virtual reality (VR) display systems. Such realistic displays are `immersive,' and allow surgeons to simultaneously see and manipulate the anatomy, to plan the procedure and to rehearse it in a realistic way. Ultimately the VR systems will be implemented in the operating room (OR) to assist the surgeon in conducting the surgery. Such an implementation will bring to the OR all of the pre-surgical planning data and rehearsal experience in synchrony with the actual patient and operation to optimize the effectiveness and outcome of the procedure.

Preoperative planning with three-dimensional reconstruction of patient's anatomy, rapid prototyping and simulation for endoscopic mitral valve repair.

PubMed

Sardari Nia, Peyman; Heuts, Samuel; Daemen, Jean; Luyten, Peter; Vainer, Jindrich; Hoorntje, Jan; Cheriex, Emile; Maessen, Jos

2017-02-01

Mitral valve repair performed by an experienced surgeon is superior to mitral valve replacement for degenerative mitral valve disease; however, many surgeons are still deterred from adapting this procedure because of a steep learning curve. Simulation-based training and planning could improve the surgical performance and reduce the learning curve. The aim of this study was to develop a patient-specific simulation for mitral valve repair and provide a proof of concept of personalized medicine in a patient prospectively planned for mitral valve surgery. A 65-year old male with severe symptomatic mitral valve regurgitation was referred to our mitral valve heart team. On the basis of three-dimensional (3D) transoesophageal echocardiography and computed tomography, 3D reconstructions of the patient's anatomy were constructed. By navigating through these reconstructions, the repair options and surgical access were chosen (minimally invasive repair). Using rapid prototyping and negative mould fabrication, we developed a process to cast a patient-specific mitral valve silicone replica for preoperative repair in a high-fidelity simulator. Mitral valve and negative mould were printed in systole to capture the pathology when the valve closes. A patient-specific mitral valve silicone replica was casted and mounted in the simulator. All repair techniques could be performed in the simulator to choose the best repair strategy. As the valve was printed in systole, no special testing other than adjusting the coaptation area was required. Subsequently, the patient was operated, mitral valve pathology was validated and repair was successfully done as in the simulation. The patient-specific simulation and planning could be applied for surgical training, starting the (minimally invasive) mitral valve repair programme, planning of complex cases and the evaluation of new interventional techniques. The personalized medicine could be a possible pathway towards enhancing reproducibility, patient's safety and effectiveness of a complex surgical procedure. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Virtual reality in radiology: virtual intervention

NASA Astrophysics Data System (ADS)

Harreld, Michael R.; Valentino, Daniel J.; Duckwiler, Gary R.; Lufkin, Robert B.; Karplus, Walter J.

1995-04-01

Intracranial aneurysms are the primary cause of non-traumatic subarachnoid hemorrhage. Morbidity and mortality remain high even with current endovascular intervention techniques. It is presently impossible to identify which aneurysms will grow and rupture, however hemodynamics are thought to play an important role in aneurysm development. With this in mind, we have simulated blood flow in laboratory animals using three dimensional computational fluid dynamics software. The data output from these simulations is three dimensional, complex and transient. Visualization of 3D flow structures with standard 2D display is cumbersome, and may be better performed using a virtual reality system. We are developing a VR-based system for visualization of the computed blood flow and stress fields. This paper presents the progress to date and future plans for our clinical VR-based intervention simulator. The ultimate goal is to develop a software system that will be able to accurately model an aneurysm detected on clinical angiography, visualize this model in virtual reality, predict its future behavior, and give insight into the type of treatment necessary. An associated database will give historical and outcome information on prior aneurysms (including dynamic, structural, and categorical data) that will be matched to any current case, and assist in treatment planning (e.g., natural history vs. treatment risk, surgical vs. endovascular treatment risks, cure prediction, complication rates).

Hip dysplasia, pelvic obliquity, and scoliosis in cerebral palsy: a qualitative analysis using 3D CT reconstruction

NASA Astrophysics Data System (ADS)

Russ, Mark D.; Abel, Mark F.

1998-06-01

Five patients with cerebral palsy, hip dysplasia, pelvic obliquity, and scoliosis were evaluated retrospectively using three dimensional computed tomography (3DCT) scans of the proximal femur, pelvis, and lumbar spine to qualitatively evaluate their individual deformities by measuring a number of anatomical landmarks. Three dimensional reconstructions of the data were visualized, analyzed, and then manipulated interactively to perform simulated osteotomies of the proximal femur and pelvis to achieve surgical correction of the hip dysplasia. Severe deformity can occur in spastic cerebral palsy, with serious consequences for the quality of life of the affected individuals and their families. Controversy exists regarding the type, timing and efficacy of surgical intervention for correction of hip dysplasia in this population. Other authors have suggested 3DCT studies are required to accurately analyze acetabular deficiency, and that this data allows for more accurate planning of reconstructive surgery. It is suggested here that interactive manipulation of the data to simulate the proposed surgery is a clinically useful extension of the analysis process and should also be considered as an essential part of the pre-operative planning to assure that the appropriate procedure is chosen. The surgical simulation may reduce operative time and improve surgical correction of the deformity.

Three-dimensional printed prototypes refine the anatomy of post-modified Norwood-1 complex aortic arch obstruction and allow presurgical simulation of the repair.

PubMed

Kiraly, Laszlo; Tofeig, Magdi; Jha, Neerod Kumar; Talo, Haitham

2016-02-01

Three-dimensional (3D) printed prototypes of malformed hearts have been used for education, communication, presurgical planning and simulation. We present a case of a 5-month old infant with complex obstruction at the neoaortic to transverse arch and descending aortic junction following the neonatal modified Norwood-1 procedure for hypoplastic left heart syndrome. Digital 3D models were created from a routine 64-slice CT dataset; then life-size solid and magnified hollow models were printed with a 3D printer. The solid model provided further insights into details of the anatomy, whereas the surgical approach and steps of the operation were simulated on the hollow model. Intraoperative assessment confirmed the anatomical accuracy of the 3D models. The operation was performed in accordance with preoperative simulation: sliding autologous flaps achieved relief of the obstruction without additional patching. Knowledge gained from the models fundamentally contributed to successful outcome and improved patient safety. This case study presents an effective use of 3D models in exploring complex spatial relationship at the aortic arch and in simulation-based planning of the operative procedure. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Study of impacts of different evaluation criteria on gamma pass rates in VMAT QA using MatriXX and EPID

NASA Astrophysics Data System (ADS)

Noufal, Manthala Padannayil; Abdullah, Kallikuzhiyil Kochunny; Niyas, Puzhakkal; Subha, Pallimanhayil Abdul Raheem

2017-12-01

Aim: This study evaluates the impacts of using different evaluation criteria on gamma pass rates in two commercially available QA methods employed for the verification of VMAT plans using different hypothetical planning target volumes (PTVs) and anatomical regions. Introduction: Volumetric modulated arc therapy (VMAT) is a widely accepted technique to deliver highly conformal treatment in a very efficient manner. As their level of complexity is high in comparison to intensity-modulated radiotherapy (IMRT), the implementation of stringent quality assurance (QA) before treatment delivery is of paramount importance. Material and Methods: Two sets of VMAT plans were generated using Eclipse planning systems, one with five different complex hypothetical three-dimensional PTVs and one including three anatomical regions. The verification of these plans was performed using a MatriXX ionization chamber array embedded inside a MultiCube phantom and a Varian EPID dosimetric system attached to a Clinac iX. The plans were evaluated based on the 3%/3 mm, 2%/2 mm, and 1%/1 mm global gamma criteria and with three low-dose threshold values (0%, 10%, and 20%). Results: The gamma pass rates were above 95% in all VMAT plans, when the 3%/3mm gamma criterion was used and no threshold was applied. In both systems, the pass rates decreased as the criteria become stricter. Higher pass rates were observed when no threshold was applied and they tended to decrease for 10% and 20% thresholds. Conclusion: The results confirm the suitability of the equipments used and the validity of the plans. The study also confirmed that the threshold settings greatly affect the gamma pass rates, especially for lower gamma criteria.

Voltera's Solution of the Wave Equation as Applied to Three-Dimensional Supersonic Airfoil Problems

NASA Technical Reports Server (NTRS)

Heslet, Max A; Lomax, Harvard; Jones, Arthur L

1947-01-01

A surface integral is developed which yields solutions of the linearized partial differential equation for supersonic flow. These solutions satisfy boundary conditions arising in wing theory. Particular applications of this general method are made, using acceleration potentials, to flat surfaces and to uniformly loaded lifting surfaces. Rectangular and trapezoidal plan forms are considered along with triangular forms adaptable to swept-forward and swept-back wings. The case of the triangular plan form in sideslip is also included. Emphasis is placed on the systematic application of the method to the lifting surfaces considered and on the possibility of further application.

Three-dimensional echocardiography of congenital abnormalities of the left atrioventricular valve.

PubMed

Rice, Kathryn; Simpson, John

2015-03-01

Congenital abnormalities of the left atrioventricular (AV) valve are a significant diagnostic challenge. Traditionally, reliance has been placed on two-dimensional echocardiographic (2DE) imaging to guide recognition of the specific morphological features. Real-time 3DE can provide unique views of the left AV valve with the potential to improve understanding of valve morphology and function to facilitate surgical planning. This review illustrates the features of congenital abnormalities of the left AV valve assessed by 3DE. The similarities and differences in morphology between different lesions are described, both with respect to the valve itself and supporting chordal apparatus. The potential advantages as well as limitations of this technique in clinical practice are outlined.

A systematic review of clinical value of three-dimensional printing in renal disease.

PubMed

Sun, Zhonghua; Liu, Dongting

2018-04-01

The aim of this systematic review is to analyse current literature related to the clinical value of three-dimensional (3D) printed models in renal disease. A literature search of PubMed and Scopus databases was performed to identify studies reporting the clinical application and usefulness of 3D printed models in renal disease. Fifteen studies were found to meet the selection criteria and were included in the analysis. Eight of them provided quantitative assessments with five studies focusing on dimensional accuracy of 3D printed models in replicating renal anatomy and tumour, and on measuring tumour volume between 3D printed models and original source images and surgical specimens, with mean difference less than 10%. The other three studies reported that the use of 3D printed models significantly enhanced medical students and specialists' ability to identify anatomical structures when compared to two-dimensional (2D) images alone; and significantly shortened intraoperative ultrasound duration compared to without use of 3D printed models. Seven studies provided qualitative assessments of the usefulness of 3D printed kidney models with findings showing that 3D printed models improved patient's understanding of renal anatomy and pathology; improved medical trainees' understanding of renal malignant tumours when compared to viewing medical images alone; and assisted surgical planning and simulation of renal surgical procedures with significant reductions of intraoperative complications. The cost and time associated with 3D printed kidney model production was reported in 10 studies, with costs ranging from USD$100 to USD$1,000, and duration of 3D printing production up to 31 h. The entire process of 3D printing could take up to a few days. This review shows that 3D printed kidney models are accurate in delineating renal anatomical structures and renal tumours with high accuracy. Patient-specific 3D printed models serve as a useful tool in preoperative planning and simulation of surgical procedures for treatment of renal tumours. Further studies with inclusion of more cases and with a focus on reducing the cost and 3D model production time deserve to be investigated.

A systematic review of clinical value of three-dimensional printing in renal disease

PubMed Central

2018-01-01

The aim of this systematic review is to analyse current literature related to the clinical value of three-dimensional (3D) printed models in renal disease. A literature search of PubMed and Scopus databases was performed to identify studies reporting the clinical application and usefulness of 3D printed models in renal disease. Fifteen studies were found to meet the selection criteria and were included in the analysis. Eight of them provided quantitative assessments with five studies focusing on dimensional accuracy of 3D printed models in replicating renal anatomy and tumour, and on measuring tumour volume between 3D printed models and original source images and surgical specimens, with mean difference less than 10%. The other three studies reported that the use of 3D printed models significantly enhanced medical students and specialists’ ability to identify anatomical structures when compared to two-dimensional (2D) images alone; and significantly shortened intraoperative ultrasound duration compared to without use of 3D printed models. Seven studies provided qualitative assessments of the usefulness of 3D printed kidney models with findings showing that 3D printed models improved patient’s understanding of renal anatomy and pathology; improved medical trainees’ understanding of renal malignant tumours when compared to viewing medical images alone; and assisted surgical planning and simulation of renal surgical procedures with significant reductions of intraoperative complications. The cost and time associated with 3D printed kidney model production was reported in 10 studies, with costs ranging from USD$100 to USD$1,000, and duration of 3D printing production up to 31 h. The entire process of 3D printing could take up to a few days. This review shows that 3D printed kidney models are accurate in delineating renal anatomical structures and renal tumours with high accuracy. Patient-specific 3D printed models serve as a useful tool in preoperative planning and simulation of surgical procedures for treatment of renal tumours. Further studies with inclusion of more cases and with a focus on reducing the cost and 3D model production time deserve to be investigated. PMID:29774184

National Program for Inspection of Non-Federal Dams. Somersville Pond Dam (CT 00273), Connecticut River Basin, Somers, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-08-01

dam. . 2.2 Construction Data. No record of original construction is avail- ’.. able for this dam. A general location plan prepared by Reino E. low Hyypa...and S"’: overuse. The slopes of the shoreline are flat and generally well covered with grass and vegetation to preclude sloughing Pp. and shoreline...roadways. It is estimated that the water depths would average 9.8 feet and that velocities of flow could cause erosion, stripping of vegetation and

Choice of radiotherapy planning modality influences toxicity in the treatment of locally advanced esophageal cancer.

PubMed

Mackley, Heath B; Adelstein, Jonathan S; Reddy, Chandana A; Adelstein, David J; Rice, Thomas W; Saxton, Jerrold P; Videtic, Gregory M M

2008-01-01

Three-dimensional computed tomography-based radiotherapy planning (3DCTP) is increasingly employed in the treatment of esophageal cancer. It is unknown whether a 3DCTP approach influences outcomes compared to two-dimensional planning (2DP). This study compares clinical outcomes for homogeneously treated patient cohorts stratified by planning modality. A retrospective chart review was conducted on patients with T3/4 and/or node-positive esophageal carcinoma treated at the Cleveland Clinic between July 1, 2003 and May 31, 2006 who were managed with an institutional regimen consisting of preoperative radiotherapy, whether 3DCTP or 2DP [30 Gy/20 fractions/1.5 Gy twice daily over 2 weeks], with concurrent cisplatin and 5-fluorouracil the first week. Following definitive resection, an identical postoperative course of concurrent chemoradiotherapy (CRT) was delivered. One hundred and forty-one patients completed preoperative CRT and were available for review. The median follow-up of living patients is 21.7 months. Fifty-five percent underwent 3DCTP and 45% had 2DP. The treatment groups were similar, with the exception of clinical stage group, with 2DP having more stage II and fewer stage III patients than 3DCTP (p = 0.02). 3DCTP plans had significantly smaller field sizes by area (p < 0.0001). Pathologic response, locoregional control, distant control, and overall survival were equivalent between the two planning modalities. Esophagitis was significantly less common with a 3D approach compared to 2D planning (49% vs. 71%, p = 0.0096), with other toxicities equivalent between the groups. 3DCTP reduces acute esophagitis in patients receiving multimodality therapy for esophageal cancer without compromising clinical outcomes.

A Subjective Assessment of Alternative Mission Architecture Operations Concepts for the Human Exploration of Mars at NASA Using a Three-Dimensional Multi-Criteria Decision Making Model

NASA Technical Reports Server (NTRS)

Tavana, Madjid

2003-01-01

The primary driver for developing missions to send humans to other planets is to generate significant scientific return. NASA plans human planetary explorations with an acceptable level of risk consistent with other manned operations. Space exploration risks can not be completely eliminated. Therefore, an acceptable level of cost, technical, safety, schedule, and political risks and benefits must be established for exploratory missions. This study uses a three-dimensional multi-criteria decision making model to identify the risks and benefits associated with three alternative mission architecture operations concepts for the human exploration of Mars identified by the Mission Operations Directorate at Johnson Space Center. The three alternatives considered in this study include split, combo lander, and dual scenarios. The model considers the seven phases of the mission including: 1) Earth Vicinity/Departure; 2) Mars Transfer; 3) Mars Arrival; 4) Planetary Surface; 5) Mars Vicinity/Departure; 6) Earth Transfer; and 7) Earth Arrival. Analytic Hierarchy Process (AHP) and subjective probability estimation are used to captures the experts belief concerning the risks and benefits of the three alternative scenarios through a series of sequential, rational, and analytical processes.

Preliminary assessment of facial soft tissue thickness utilizing three-dimensional computed tomography models of living individuals.

PubMed

Parks, Connie L; Richard, Adam H; Monson, Keith L

2014-04-01

Facial approximation is the technique of developing a representation of the face from the skull of an unknown individual. Facial approximation relies heavily on average craniofacial soft tissue depths. For more than a century, researchers have employed a broad array of tissue depth collection methodologies, a practice which has resulted in a lack of standardization in craniofacial soft tissue depth research. To combat such methodological inconsistencies, Stephan and Simpson 2008 [15] examined and synthesized a large number of previously published soft tissue depth studies. Their comprehensive meta-analysis produced a pooled dataset of averaged tissue depths and a simplified methodology, which the researchers suggest be utilized as a minimum standard protocol for future craniofacial soft tissue depth research. The authors of the present paper collected craniofacial soft tissue depths using three-dimensional models generated from computed tomography scans of living males and females of four self-identified ancestry groups from the United States ranging in age from 18 to 62 years. This paper assesses the differences between: (i) the pooled mean tissue depth values from the sample utilized in this paper and those published by Stephan 2012 [21] and (ii) the mean tissue depth values of two demographically similar subsets of the sample utilized in this paper and those published by Rhine and Moore 1984 [16]. Statistical test results indicate that the tissue depths collected from the sample evaluated in this paper are significantly and consistently larger than those published by Stephan 2012 [21]. Although a lack of published variance data by Rhine and Moore 1984 [16] precluded a direct statistical assessment, a substantive difference was also concluded. Further, the dataset presented in this study is representative of modern American adults and is, therefore, appropriate for use in constructing contemporary facial approximations. Published by Elsevier Ireland Ltd.

Succession planning in US pharmacy schools.

PubMed

Van Amburgh, Jenny; Surratt, Christopher K; Green, James S; Gallucci, Randle M; Colbert, James; Zatopek, Shara L; Blouin, Robert A

2010-06-15

The deans, associate and assistant deans, and department chairs of a college or school of pharmacy retain historic memories of the institution and share the responsibility for day-to-day operation, sustainability, and future planning. Between the anticipated retirement of baby boomers who are senior administrative faculty members and the steady increase in number of colleges and schools of pharmacy, the academy is facing a shortage of qualified successors. Succession planning involves planning for the effective transition of personnel in leadership positions within an organization. This paper describes the subject of succession planning at a sample population of AACP institutions by obtaining perspectives on the subject from the deans of these institutions via standardized interview instruments. The instruments were utilized with 15 deans; all interview data were blinded and analyzed using analyst triangulation. The majority of deans responded that some level of succession planning was desirable and even necessary; however, none claimed to have a formal succession planning structure in place at his or her home institution. Although widely accepted and well-recognized in the corporate and military sectors, succession planning within pharmacy schools and colleges is neither universally documented nor implemented. Differences exist within the administrative structure of these non-academic and academic institutions that may preclude a uniform succession planning format. While the evidence presented suggests that succession planning is needed within the academy, a concerted effort must be made towards implementing its practice.

Succession Planning in US Pharmacy Schools

PubMed Central

Surratt, Christopher K.; Green, James S.; Gallucci, Randle M.; Colbert, James; Zatopek, Shara L.; Blouin, Robert A.

2010-01-01

The deans, associate and assistant deans, and department chairs of a college or school of pharmacy retain historic memories of the institution and share the responsibility for day-to-day operation, sustainability, and future planning. Between the anticipated retirement of baby boomers who are senior administrative faculty members and the steady increase in number of colleges and schools of pharmacy, the academy is facing a shortage of qualified successors. Succession planning involves planning for the effective transition of personnel in leadership positions within an organization. This paper describes the subject of succession planning at a sample population of AACP institutions by obtaining perspectives on the subject from the deans of these institutions via standardized interview instruments. The instruments were utilized with 15 deans; all interview data were blinded and analyzed using analyst triangulation. The majority of deans responded that some level of succession planning was desirable and even necessary; however, none claimed to have a formal succession planning structure in place at his or her home institution. Although widely accepted and well-recognized in the corporate and military sectors, succession planning within pharmacy schools and colleges is neither universally documented nor implemented. Differences exist within the administrative structure of these non-academic and academic institutions that may preclude a uniform succession planning format. While the evidence presented suggests that succession planning is needed within the academy, a concerted effort must be made towards implementing its practice. PMID:20798799

U.S. Materials Science on the International Space Station: Status and Plans

NASA Technical Reports Server (NTRS)

Chiaramonte, Francis P.; Kelton, Kenneth F.; Matson, Douglas M.; Poirier, David R.; Trivedi, Rohit K.; Su, Ching-Hua; Volz, Martin P.; Voorhees, Peter W.

2010-01-01

This viewgraph presentation reviews the current status and NASA plans for materials science on the International Space Station. The contents include: 1) Investigations Launched in 2009; 2) DECLIC in an EXPRESS rack; 3) Dynamical Selection of Three-Dimensional Interface Patterns in Directional Solidification (DSIP); 4) Materials Science Research Rack (MSRR); 5) Materials Science Laboratory; 6) Comparison of Structure and Segregation in Alloys Directionally Solidified in Terrestrial and Microgravity Environments (MICAST/CETSOL); 7) Coarsening in Solid Liquid Mixtures 2 Reflight (CSLM 2R); 8) Crystal Growth Investigations; 9) Levitator Investigations; 10) Quasi Crystalline Undercooled Alloys for Space Investigation (QUASI); 11) The Role of Convection and Growth Competition in Phase Selection in Microgravity (LODESTARS); 12) Planned Additional Investigations; 13) SETA; 14) METCOMP; and 15) Materials Science NRA.

Quality assurance of intensity-modulated radiation therapy.

PubMed

Palta, Jatinder R; Liu, Chihray; Li, Jonathan G

2008-01-01

The current paradigm for the quality assurance (QA) program for intensity-modulated radiation therapy (IMRT) includes QA of the treatment planning system, QA of the delivery system, and patient-specific QA. Although the IMRT treatment planning and delivery system is the same as for conventional three-dimensional conformal radiation therapy, it has more parameters to coordinate and verify. Because of complex beam intensity modulation, each IMRT field often includes many small irregular off-axis fields, resulting in isodose distributions for each IMRT plan that are more conformal than those from conventional treatment plans. Therefore, these features impose a new and more stringent set of QA requirements for IMRT planning and delivery. The generic test procedures to validate dose calculation and delivery accuracy for both treatment planning and IMRT delivery have to be customized for each type of IMRT planning and delivery strategy. The rationale for such an approach is that the overall accuracy of IMRT delivery is incumbent on the piecewise uncertainties in both the planning and delivery processes. The end user must have well-defined evaluation criteria for each element of the planning and delivery process. Such information can potentially be used to determine a priori the accuracy of IMRT planning and delivery.

Stereophotogrammetric analysis of nasolabial morphology among Asian Malays: influence of age and sex.

PubMed

Al-Khatib, Ali R; Rajion, Zainul A; Masudi, Sam'an M; Hassan, Rozita; Anderson, Peter J; Townsend, Grant C

2012-07-01

It is clear that population-specific norms should be used when planning plastic and reconstructive surgery for selected patients. In this study, we aimed to generate nasal and labial reference values by applying a stereophotogrammetric technique. A further aim was to investigate the effect of sexual dimorphism, age-related changes, and the interrelation between nasal and labial morphology. Cross-sectional study. The data were collected from different locations on the Malaysian peninsula. A total of 276 Asian Malays (138 males and 138 females) were included in this study, and a three-dimensional system was used for capturing data. The sample was divided into three age groups: 13 to 14, 15 to 17, and 18 to 36 years. Twenty-five dimensions of the nose and lips were measured and analyzed separately in males and females. Significant differences between males and females were identified in 11 distances, and significant effects of age were found in most of the dimensions (p < .05). Significant correlations between the nasal and labial dimensions were recorded, particularly between lateral lip height and width of the ala insertion. A principal component analysis showed interrelationships between the nasal width distances and upper lip height. This study has provided a new three-dimensional database for nose and lip morphology in Malays and demonstrated patterns of variation that can be used by surgeons to make comparisons within and between different human populations and also to develop treatment plans for their patients.

A three-dimensional digital atlas of the dura mater based on human head MRI.

PubMed

Yang, Zhirong; Guo, Zhilin

2015-03-30

The goal of this paper was to design a three-dimensional (3D) digital dural atlas of the human brain for assisting neurosurgeons during the planning of an operation, medical research and teaching activities in neurosurgical anatomy. The 176 sagittal head magnetic resonance(MR) images of a 54-year-old female who suffered from the left posterior fossa tumor were processed and outlined, based on which a 3D dural model was created using the softwares of 3ds-max and Mimics. Then the model and images/anatomy photos were matched using the softwares of Z-brush and Photoshop to form the 3-D dural atlas. Dural anatomic photographs were needed to produce the 3D atlas in dural vault and skull base areas. The 3D dural atlas of the brain and related structures was successfully constructed using 73 dural delineations, the contours of dural model match very well on the dural structures of the original images in three orthogonal (axial, coronal and sagittal view) MR cross-sections. The atlas can be arbitrarily rotated and viewed from any direction. It can also be zoomed in and out directly using the zoom function. We successfully generated a 3D dural atlas of human brain, which can be used for repeated observation and research without limitations of time and shortage of corpses. In addition, the atlas has many potential applications in operative planning, surgical training, teaching activities, and so on. Copyright © 2014 Elsevier B.V. All rights reserved.

Design and analysis of advanced flight planning concepts

NASA Technical Reports Server (NTRS)

Sorensen, John A.

1987-01-01

The objectives of this continuing effort are to develop and evaluate new algorithms and advanced concepts for flight management and flight planning. This includes the minimization of fuel or direct operating costs, the integration of the airborne flight management and ground-based flight planning processes, and the enhancement of future traffic management systems design. Flight management (FMS) concepts are for on-board profile computation and steering of transport aircraft in the vertical plane between a city pair and along a given horizontal path. Flight planning (FPS) concepts are for the pre-flight ground based computation of the three-dimensional reference trajectory that connects the city pair and specifies the horizontal path, fuel load, and weather profiles for initializing the FMS. As part of these objectives, a new computer program called EFPLAN has been developed and utilized to study advanced flight planning concepts. EFPLAN represents an experimental version of an FPS. It has been developed to generate reference flight plans compatible as input to an FMS and to provide various options for flight planning research. This report describes EFPLAN and the associated research conducted in its development.

Three dimensional identification card and applications

NASA Astrophysics Data System (ADS)

Zhou, Changhe; Wang, Shaoqing; Li, Chao; Li, Hao; Liu, Zhao

2016-10-01

Three dimensional Identification Card, with its three-dimensional personal image displayed and stored for personal identification, is supposed be the advanced version of the present two-dimensional identification card in the future [1]. Three dimensional Identification Card means that there are three-dimensional optical techniques are used, the personal image on ID card is displayed to be three-dimensional, so we can see three dimensional personal face. The ID card also stores the three-dimensional face information in its inside electronics chip, which might be recorded by using two-channel cameras, and it can be displayed in computer as three-dimensional images for personal identification. Three-dimensional ID card might be one interesting direction to update the present two-dimensional card in the future. Three-dimension ID card might be widely used in airport custom, entrance of hotel, school, university, as passport for on-line banking, registration of on-line game, etc...

Differential Diagnosis of Selective Mutism in Bilingual Children

ERIC Educational Resources Information Center

Toppelberg, Claudio O.; Tabors, Patton; Coggins, Alissa; Lum, Kirk; Burger, Claudia

2005-01-01

Early diagnosis of selective mutism (SM) is an important concern. SM prevalence is higher than initially thought and at least three times higher in immigrant language minority children. Although the DSM-IV precludes diagnosing SM in immigrant children with limited language proficiency (as children acquiring a second language may normally undergo a…

Percutaneous Transcatheter Mitral Valve Replacement: Patient-specific Three-dimensional Computer-based Heart Model and Prototyping.

PubMed

Vaquerizo, Beatriz; Theriault-Lauzier, Pascal; Piazza, Nicolo

2015-12-01

Mitral regurgitation is the most prevalent valvular heart disease worldwide. Despite the widespread availability of curative surgical intervention, a considerable proportion of patients with severe mitral regurgitation are not referred for treatment, largely due to the presence of left ventricular dysfunction, advanced age, and comorbid illnesses. Transcatheter mitral valve replacement is a promising therapeutic alternative to traditional surgical valve replacement. The complex anatomical and pathophysiological nature of the mitral valvular complex, however, presents significant challenges to the successful design and implementation of novel transcatheter mitral replacement devices. Patient-specific 3-dimensional computer-based models enable accurate assessment of the mitral valve anatomy and preprocedural simulations for transcatheter therapies. Such information may help refine the design features of novel transcatheter mitral devices and enhance procedural planning. Herein, we describe a novel medical image-based processing tool that facilitates accurate, noninvasive assessment of the mitral valvular complex, by creating precise three-dimensional heart models. The 3-dimensional computer reconstructions are then converted to a physical model using 3-dimensional printing technology, thereby enabling patient-specific assessment of the interaction between device and patient. It may provide new opportunities for a better understanding of the mitral anatomy-pathophysiology-device interaction, which is of critical importance for the advancement of transcatheter mitral valve replacement. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Design and evaluation of a software prototype for participatory planning of environmental adaptations.

PubMed

Eriksson, J; Ek, A; Johansson, G

2000-03-01

A software prototype to support the planning process for adapting home and work environments for people with physical disabilities was designed and later evaluated. The prototype exploits low-cost three-dimensional (3-D) graphics products in the home computer market. The essential features of the prototype are: interactive rendering with optional hardware acceleration, interactive walk-throughs, direct manipulation tools for moving objects and measuring distances, and import of 3-D-objects from a library. A usability study was conducted, consisting of two test sessions (three weeks apart) and a final interview. The prototype was then tested and evaluated by representatives of future users: five occupational therapist students, and four persons with physical disability, with no previous experience of the prototype. Emphasis in the usability study was placed on the prototype's efficiency and learnability. We found that it is possible to realise a planning tool for environmental adaptations, both regarding usability and technical efficiency. The usability evaluation confirms our findings from previous case studies, regarding the relevance and positive attitude towards this kind of planning tool. Although the prototype was found to be satisfactorily efficient for the basic tasks, the paper presents several suggestions for improvement of future prototype versions.

Technical aspects of virtual liver resection planning.

PubMed

Glombitza, G; Lamadé, W; Demiris, A M; Göpfert, M R; Mayer, A; Bahner, M L; Meinzer, H P; Richter, G; Lehnert, T; Herfarth, C

1998-01-01

Operability of a liver tumor is depending on its three dimensional relation to the intrahepatic vascular trees which define autonomously functioning liver (sub-)segments. Precise operation planning is complicated by anatomic variability, distortion of the vascular trees by the tumor or preceding liver resections. Because of the missing possibility to track the deformation of the liver during the operation an integration of the resection planning system into an intra-operative navigation system is not feasible. So the main task of an operation planning system in this domain is a quantifiable patient selection by exact prediction of post-operative liver function and a quantifiable resection proposal. The system quantifies the organ structures and resection volumes by means of absolute and relative values. It defines resection planes depending on security margins and the vascular trees and presents the data in visualized form as a 3D movie. The new 3D operation planning system offers quantifiable liver resection proposals based on individualized liver anatomy. The results are visualized in digital movies as well as in quantitative reports.

PubMed Central

ACHILLES, N.; PASCH, N.; LINTERMANN, A.; SCHRÖDER, W.; MÖSGES, R.

2013-01-01

SUMMARY This systematic review aims first to summarize the previous areas of application of computational fluid dynamics (CFD) and then to demonstrate that CFD is also a suitable instrument for generating three-dimensional images that depict drug effects on nasal mucosa. Special emphasis is placed on the three-dimensional visualization of the antiobstructive effect of nasal steroids and antihistamines in the treatment of allergic rhinitis. In the beginning, CFD technology was only used to demonstrate physiological and pathophysiological airflow conditions in the nose and to aid in preoperative planning and postoperative monitoring of surgical outcome in the field of rhinosurgery. The first studies using CFD examined nasal respiratory physiology, important functions of the nose, such as conditioning and warming of inspired air, and the influence of pathophysiological changes on nasal breathing. Also, postoperative outcome of surgical procedures could be "predicted" using the nasal airflow model. Later studies focused on the three-dimensional visualization of the effect of nasal sprays in healthy subjects and postoperative patients. A completely new approach, however, was the use of CFD in the area of allergic rhinitis and the treatment of its cardinal symptom of nasal obstruction. In two clinical trials, a suitable patient with a positive history of allergic rhinitis was enrolled during a symptom-free period after the pollen season. The patient developed typical allergic rhinitis symptoms after provocation with birch pollen. The 3-D visualization showed that the antiallergic treatment successfully counteracted the effects of nasal allergen provocation on nasal airflow. These observations were attributed to the antiobstructive effect of a nasal steroid (mometasone furoate) and a systemic antihistamine (levocetirizine), respectively. CFD therefore constitutes a non-invasive, precise, reliable and objective examination procedure for generating three-dimensional images that depict the effects of drugs used in the treatment of allergic rhinitis. PMID:23620638

Efficacy of chordal cutting in alleviating ischemic mitral regurgitation: insights from 3-dimensional echocardiography

PubMed Central

Sai-Sudhakar, Chittoor B; Vandse, Rashmi; Armen, Todd A; Bickle, Katherine M; Nathan, Nadia S

2007-01-01

Background Ischemic mitral regurgitation often complicates severe ischemic heart disease and adversely affects the prognosis in these patients. There is wide variation in the clinical spectrum of ischemic mitral regurgitation due to varying location and chronicity of ischemia and anomalies in annular and ventricular remodeling. As a result, there is lack of consensus in treating these patients. Treatment has to be individualized for each patient. Most of the available surgical options do not consistently correct this condition in all the patients. Chordal cutting is one of the newer surgical approaches in which cutting a limited number of critically positioned basal chordae have found success by relieving the leaflet tethering and thereby improving the coaptation of leaflets. Three-dimensional echocardiography is a potentially valuable tool in identifying the specific pattern of tethering and thus the suitability of this procedure in a given clinical scenario. Case Presentation A 66-year-old man with cardiomyopathy and ischemic mitral regurgitation presented to us with the features of congestive heart failure. The three-dimensional echocardiography revealed severe mitral regurgitation associated with the tethering of the lateral (P1) and medial (P3) scallops of the posterior leaflet of the mitral valve due to secondary chordal attachments. The ejection fraction was only 15% with severe global systolic and diastolic dysfunction. Mitral regurgitation was successfully corrected with mitral annuloplasty and resection of the secondary chordae tethering the medial and lateral scallops of the posterior leaflet of the mitral valve. Conclusion Cutting the second order chordae along with mitral annuloplasty could be a novel method to remedy Ischemic mitral regurgitation by relieving the tethering of the valve leaflets. The preoperative three-dimensional echocardiography should be considered in all patients with Ischemic mitral regurgitation to assess the complex three-dimensional interactions between the mitral valve apparatus and the left ventricle. This aids in timely surgical planning. PMID:17894872

Efficacy of chordal cutting in alleviating ischemic mitral regurgitation: insights from 3-dimensional echocardiography.

PubMed

Sai-Sudhakar, Chittoor B; Vandse, Rashmi; Armen, Todd A; Bickle, Katherine M; Nathan, Nadia S

2007-09-25

Ischemic mitral regurgitation often complicates severe ischemic heart disease and adversely affects the prognosis in these patients. There is wide variation in the clinical spectrum of ischemic mitral regurgitation due to varying location and chronicity of ischemia and anomalies in annular and ventricular remodeling. As a result, there is lack of consensus in treating these patients. Treatment has to be individualized for each patient. Most of the available surgical options do not consistently correct this condition in all the patients. Chordal cutting is one of the newer surgical approaches in which cutting a limited number of critically positioned basal chordae have found success by relieving the leaflet tethering and thereby improving the coaptation of leaflets. Three-dimensional echocardiography is a potentially valuable tool in identifying the specific pattern of tethering and thus the suitability of this procedure in a given clinical scenario. A 66-year-old man with cardiomyopathy and ischemic mitral regurgitation presented to us with the features of congestive heart failure. The three-dimensional echocardiography revealed severe mitral regurgitation associated with the tethering of the lateral (P1) and medial (P3) scallops of the posterior leaflet of the mitral valve due to secondary chordal attachments. The ejection fraction was only 15% with severe global systolic and diastolic dysfunction. Mitral regurgitation was successfully corrected with mitral annuloplasty and resection of the secondary chordae tethering the medial and lateral scallops of the posterior leaflet of the mitral valve. Cutting the second order chordae along with mitral annuloplasty could be a novel method to remedy Ischemic mitral regurgitation by relieving the tethering of the valve leaflets. The preoperative three-dimensional echocardiography should be considered in all patients with Ischemic mitral regurgitation to assess the complex three-dimensional interactions between the mitral valve apparatus and the left ventricle. This aids in timely surgical planning.

Vertically Integrated Models for Carbon Storage Modeling in Heterogeneous Domains

NASA Astrophysics Data System (ADS)

Bandilla, K.; Celia, M. A.

2017-12-01

Numerical modeling is an essential tool for studying the impacts of geologic carbon storage (GCS). Injection of carbon dioxide (CO2) into deep saline aquifers leads to multi-phase flow (injected CO2 and resident brine), which can be described by a set of three-dimensional governing equations, including mass-balance equation, volumetric flux equations (modified Darcy), and constitutive equations. This is the modeling approach on which commonly used reservoir simulators such as TOUGH2 are based. Due to the large density difference between CO2 and brine, GCS models can often be simplified by assuming buoyant segregation and integrating the three-dimensional governing equations in the vertical direction. The integration leads to a set of two-dimensional equations coupled with reconstruction operators for vertical profiles of saturation and pressure. Vertically-integrated approaches have been shown to give results of comparable quality as three-dimensional reservoir simulators when applied to realistic CO2 injection sites such as the upper sand wedge at the Sleipner site. However, vertically-integrated approaches usually rely on homogeneous properties over the thickness of a geologic layer. Here, we investigate the impact of general (vertical and horizontal) heterogeneity in intrinsic permeability, relative permeability functions, and capillary pressure functions. We consider formations involving complex fluvial deposition environments and compare the performance of vertically-integrated models to full three-dimensional models for a set of hypothetical test cases consisting of high permeability channels (streams) embedded in a low permeability background (floodplains). The domains are randomly generated assuming that stream channels can be represented by sinusoidal waves in the plan-view and by parabolas for the streams' cross-sections. Stream parameters such as width, thickness and wavelength are based on values found at the Ketzin site in Germany. Results from the vertically-integrated approach are compared to results using TOUGH2, both in terms of depth-averaged saturation and vertical saturation profiles.

Animation and radiobiological analysis of 3D motion in conformal radiotherapy.

PubMed

MacKay, R I; Graham, P A; Moore, C J; Logue, J P; Sharrock, P J

1999-07-01

To allow treatment plans to be evaluated against the range of expected organ motion and set up error anticipated during treatment. Planning tools have been developed to allow concurrent animation and radiobiological analysis of three dimensional (3D) target and organ motion in conformal radiotherapy. Surfaces fitted to structures outlined on CT studies are projected onto pre-treatment images or onto megavoltage images collected during the patient treatment. Visual simulation of tumour and normal tissue movement is then performed by the application of three dimensional affine transformations, to the selected surface. Concurrent registration of the surface motion with the 3D dose distribution allows calculation of the change in dose to the volume. Realistic patterns of motion can be applied to the structure to simulate inter-fraction motion and set-up error. The biologically effective dose for the structure is calculated for each fraction as the surface moves over the course of the treatment and is used to calculate the normal tissue complication probability (NTCP) or tumour control probability (TCP) for the moving structure. The tool has been used to evaluate conformal therapy plans against set up measurements recorded during patient treatments. NTCP and TCP were calculated for a patient whose set up had been corrected after systematic deviations from plan geometry were measured during treatment, the effect of not making the correction were also assessed. TCP for the moving tumour was reduced if inadequate margins were set for the treatment. Modelling suggests that smaller margins could have been set for the set up corrected during the course of the treatment. The NTCP for the rectum was also higher for the uncorrected set up due to a more rectal tissue falling in the high dose region. This approach provides a simple way for clinical users to utilise information incrementally collected throughout the whole of a patient's treatment. In particular it is possible to test the robustness of a patient plan against a range of possible motion patterns. The methods described represent a move from the inspection of static pre-treatment plans to a review of the dynamic treatment.

Comparison of patient-specific instruments with standard surgical instruments in determining glenoid component position: a randomized prospective clinical trial.

PubMed

Hendel, Michael D; Bryan, Jason A; Barsoum, Wael K; Rodriguez, Eric J; Brems, John J; Evans, Peter J; Iannotti, Joseph P

2012-12-05

Glenoid component malposition for anatomic shoulder replacement may result in complications. The purpose of this study was to define the efficacy of a new surgical method to place the glenoid component. Thirty-one patients were randomized for glenoid component placement with use of either novel three-dimensional computed tomographic scan planning software combined with patient-specific instrumentation (the glenoid positioning system group), or conventional computed tomographic scan, preoperative planning, and surgical technique, utilizing instruments provided by the implant manufacturer (the standard surgical group). The desired position of the component was determined preoperatively. Postoperatively, a computed tomographic scan was used to define and compare the actual implant location with the preoperative plan. In the standard surgical group, the average preoperative glenoid retroversion was -11.3° (range, -39° to 17°). In the glenoid positioning system group, the average glenoid retroversion was -14.8° (range, -27° to 7°). When the standard surgical group was compared with the glenoid positioning system group, patient-specific instrumentation technology significantly decreased (p < 0.05) the average deviation of implant position for inclination and medial-lateral offset. Overall, the average deviation in version was 6.9° in the standard surgical group and 4.3° in the glenoid positioning system group. The average deviation in inclination was 11.6° in the standard surgical group and 2.9° in the glenoid positioning system group. The greatest benefit of patient-specific instrumentation was observed in patients with retroversion in excess of 16°; the average deviation was 10° in the standard surgical group and 1.2° in the glenoid positioning system group (p < 0.001). Preoperative planning and patient-specific instrumentation use resulted in a significant improvement in the selection and use of the optimal type of implant and a significant reduction in the frequency of malpositioned glenoid implants. Novel three-dimensional preoperative planning, coupled with patient and implant-specific instrumentation, allows the surgeon to better define the preoperative pathology, select the optimal implant design and location, and then accurately execute the plan at the time of surgery.

Raising the Quality of Teaching in Public Schools of Pakistan: A Three Dimensional Analysis for Capacity Development of In-Service Teachers in Instructional Planning and Strategies

ERIC Educational Resources Information Center

Rizwan, Sidra; Khan, Rehana Masrur

2015-01-01

In order to prepare the upcoming generation to handle the sophisticated skills required to contribute to a knowledge-based society, the teachers need to be more successful with the learners having varied needs and learning styles. Development of teachers on the basis of professional standards is part of a broader movement for the assurance of…

The concept and evolution of involved site radiation therapy for lymphoma.

PubMed

Specht, Lena; Yahalom, Joachim

2015-10-01

We describe the development of radiation therapy for lymphoma from extended field radiotherapy of the past to modern conformal treatment with involved site radiation therapy based on advanced imaging, three-dimensional treatment planning and advanced treatment delivery techniques. Today, radiation therapy is part of the multimodality treatment of lymphoma, and the irradiated tissue volume is much smaller than before, leading to highly significant reductions in the risks of long-term complications.

Congenital malformations of the skull and meninges.

PubMed

Kanev, Paul M

2007-02-01

The surgery and management of children who have congenital malformations of the skull and meninges require multidisciplinary care and long-term follow-up by multiple specialists in birth defects. The high definition of three-dimensional CT and MRI allows precise surgery planning of reconstruction and management of associated malformations. The reconstruction of meningoencephaloceles and craniosynostosis are challenging procedures that transform the child's appearance. The embryology, clinical presentation, and surgical management of these malformations are reviewed.

TH-A-9A-04: Incorporating Liver Functionality in Radiation Therapy Treatment Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, V; Epelman, M; Feng, M

2014-06-15

Purpose: Liver SBRT patients have both variable pretreatment liver function (e.g., due to degree of cirrhosis and/or prior treatments) and sensitivity to radiation, leading to high variability in potential liver toxicity with similar doses. This work aims to explicitly incorporate liver perfusion into treatment planning to redistribute dose to preserve well-functioning areas without compromising target coverage. Methods: Voxel-based liver perfusion, a measure of functionality, was computed from dynamic contrast-enhanced MRI. Two optimization models with different cost functions subject to the same dose constraints (e.g., minimum target EUD and maximum critical structure EUDs) were compared. The cost functions minimized were EUDmore » (standard model) and functionality-weighted EUD (functional model) to the liver. The resulting treatment plans delivering the same target EUD were compared with respect to their DVHs, their dose wash difference, the average dose delivered to voxels of a particular perfusion level, and change in number of high-/low-functioning voxels receiving a particular dose. Two-dimensional synthetic and three-dimensional clinical examples were studied. Results: The DVHs of all structures of plans from each model were comparable. In contrast, in plans obtained with the functional model, the average dose delivered to high-/low-functioning voxels was lower/higher than in plans obtained with its standard counterpart. The number of high-/low-functioning voxels receiving high/low dose was lower in the plans that considered perfusion in the cost function than in the plans that did not. Redistribution of dose can be observed in the dose wash differences. Conclusion: Liver perfusion can be used during treatment planning potentially to minimize the risk of toxicity during liver SBRT, resulting in better global liver function. The functional model redistributes dose in the standard model from higher to lower functioning voxels, while achieving the same target EUD and satisfying dose limits to critical structures. This project is funded by MCubed and grant R01-CA132834.« less

The segment as the minimal planning unit in speech production and reading aloud: evidence and implications.

PubMed

Kawamoto, Alan H; Liu, Qiang; Kello, Christopher T

2015-01-01

Speech production and reading aloud studies have much in common, especially the last stages involved in producing a response. We focus on the minimal planning unit (MPU) in articulation. Although most researchers now assume that the MPU is the syllable, we argue that it is at least as small as the segment based on negative response latencies (i.e., response initiation before presentation of the complete target) and longer initial segment durations in a reading aloud task where the initial segment is primed. We also discuss why such evidence was not found in earlier studies. Next, we rebut arguments that the segment cannot be the MPU by appealing to flexible planning scope whereby planning units of different sizes can be used due to individual differences, as well as stimulus and experimental design differences. We also discuss why negative response latencies do not arise in some situations and why anticipatory coarticulation does not preclude the segment MPU. Finally, we argue that the segment MPU is also important because it provides an alternative explanation of results implicated in the serial vs. parallel processing debate.

Shuttle/Agena study. Volume 2, part 3: Preliminary test plans

NASA Technical Reports Server (NTRS)

1972-01-01

Proposed testing for the Agena tug program is based upon best estimates of shuttle and Agena tug requirements and upon the Agena configuration currently envisioned to meet these requirements. The proposed tests are presented in development, qualification, system, and launch base test plans. These plans are based upon generalized requirements and assumed situations. The limitations of this study precluded all but minimal consideration of related shuttle orbiter and shuttle ground systems. The test plans include provisions for all testing from major component to systems level, identified as necessary to aid in confirmation of the modified Agena configuration for the space tug; considerations that crew safety requirements and new environmental conditions from shuttle interface effects do impose some new Agena testing requirements; considerations that many existing Agena flight-qualified components will be utilized and qualification testing will be minimal; testing not only for the Agena tug but also for new or modified items of handling or servicing equipment for supporting the Agena factory-to-launch sequence; and the assembly of required testing into a sequence-ordered series of events.

Administration of egg-derived vaccines in patients with history of egg sensitivity.

PubMed

Kletz, M R; Holland, C L; Mendelson, J S; Bielory, L

1990-06-01

A history of a prior hypersensitivity reaction to egg has precluded patients from receiving egg-derived vaccines. We present three cases of successful administration of egg-derived vaccines; specifically influenza and measles, mumps, and rubella (MMR) to patients with egg hypersensitivity. Two were given influenza vaccine without incident and one was successfully desensitized to MMR. Skin testing and desensitization protocols are described. Desensitization to all three components of MMR has not been reported previously.

Two-dimensional planning can result in internal rotation of the femoral component in total knee arthroplasty.

PubMed

Okamoto, Shigetoshi; Mizu-uchi, Hideki; Okazaki, Ken; Hamai, Satoshi; Tashiro, Yasutaka; Nakahara, Hiroyuki; Iwamoto, Yukihide

2016-01-01

The first purpose of this study was to compare the reproducibility of two-dimensional (2D) and three-dimensional (3D) measurements for preoperative planning of the femoral side in total knee arthroplasty (TKA). The second purpose was to evaluate the factors affecting the differences between the 2D and 3D measurements. Two-dimensional and 3D measurements for preoperative planning of the femoral side in TKA were evaluated in 75 varus knees with osteoarthritis. The femoral valgus angle, defined as the angle between the mechanical and anatomical axes of the femur, and the clinical rotation angle and surgical rotation angle, defined by the angles between the posterior condylar line and the clinical or surgical transepicondylar axes, respectively, were analysed using 2D (radiographs and axial CT slices) and 3D (3D bone models reconstructed from CT images) measurements. For all variables, 3D measurements were more reliable and reproducible than 2D measurements. The medians and ranges of the clinical rotation angle and surgical rotation angle were 6.6° (-1.7° to 12.1°) and 2.3° (-2.5° to 8.6°) in 2D, and 7.1° (2.7° to 11.4°) and 3.0° (-2.0° to 7.5°) in 3D. Varus/valgus alteration of the CT scanning direction relative to the mechanical axis affected the difference in clinical rotation angles between 2D and 3D measurements. Significantly, smaller values of the clinical rotation angle and surgical rotation angle were obtained by 2D compared to 3D measurements, which could result in internal rotation of the femoral component even if the surgeon performs the bone cutting precisely. Regarding clinical relevance, first, this study confirmed the reliability of 3D measurements. Second, it underscored the risk of internal rotation of the femoral component when using 2D measurement, even with precise bone cutting technique. These results will help surgeons avoid malpositioning of the femoral component if 2D measurements are used for preoperative planning in TKA. Prospective comparative study, Level Ш.

Feasibility and accuracy of computational robot-assisted partial nephrectomy planning by virtual partial nephrectomy analysis.

PubMed

Isotani, Shuji; Shimoyama, Hirofumi; Yokota, Isao; China, Toshiyuki; Hisasue, Shin-ichi; Ide, Hisamitsu; Muto, Satoru; Yamaguchi, Raizo; Ukimura, Osamu; Horie, Shigeo

2015-05-01

To evaluate the feasibility and accuracy of virtual partial nephrectomy analysis, including a color-coded three-dimensional virtual surgical planning and a quantitative functional analysis, in predicting the surgical outcomes of robot-assisted partial nephrectomy. Between 2012 and 2014, 20 patients underwent virtual partial nephrectomy analysis before undergoing robot-assisted partial nephrectomy. Virtual partial nephrectomy analysis was carried out with the following steps: (i) evaluation of the arterial branch for selective clamping by showing the vascular-supplied area; (ii) simulation of the optimal surgical margin in precise segmented three-dimensional model for prediction of collecting system opening; and (iii) detailed volumetric analyses and estimates of postoperative renal function based on volumetric change. At operation, the surgeon identified the targeted artery and determined the surgical margin according to the virtual partial nephrectomy analysis. The surgical outcomes between the virtual partial nephrectomy analysis and the actual robot-assisted partial nephrectomy were compared. All 20 patients had negative cancer surgical margins and no urological complications. The tumor-specific renal arterial supply areas were shown in color-coded three-dimensional model visualization in all cases. The prediction value of collecting system opening was 85.7% for sensitivity and 100% for specificity. The predicted renal resection volume was significantly correlated with actual resected specimen volume (r(2) = 0.745, P < 0.001). The predicted estimated glomerular filtration rate was significantly correlated with actual postoperative estimated glomerular filtration rate (r(2) = 0.736, P < 0.001). Virtual partial nephrectomy analysis is able to provide the identification of tumor-specific renal arterial supply, prediction of collecting system opening and prediction of postoperative renal function. This technique might allow urologists to compare various arterial clamping methods and resection margins with surgical outcomes in a non-invasive manner. © 2015 The Japanese Urological Association.

Adjuvant Chemoradiation for Gastric Cancer Using Epirubicin, Cisplatin, and 5-Fluorouracil Before and After Three-Dimensional Conformal Radiotherapy With Concurrent Infusional 5-Fluorouracil: A Multicenter Study of the Trans-Tasman Radiation Oncology Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leong, Trevor, E-mail: trevor.leong@petermac.or; Joon, Daryl Lim; Willis, David

Purpose: The INT0116 study has established postoperative chemoradiotherapy as the standard of care for completely resected gastric adenocarcinoma. However, the optimal chemoradiation regimen remains to be defined. We conducted a prospective, multicenter study to evaluate an alternative chemoradiation regimen that combines more current systemic treatment with modern techniques of radiotherapy delivery. Methods and Materials: Patients with adenocarcinoma of the stomach who had undergone an R0 resection were eligible. Adjuvant therapy consisted of one cycle of epirubicin, cisplatin, and 5-FU (ECF), followed by radiotherapy with concurrent infusional 5-FU, and then two additional cycles of ECF. Radiotherapy was delivered using precisely defined,more » multiple-field, three-dimensional conformal techniques. Results: A total of 54 assessable patients were enrolled from 19 institutions. The proportion of patients commencing Cycles 1, 2, and 3 of ECF chemotherapy were 100%, 81%, and 67% respectively. In all, 94% of patients who received radiotherapy completed treatment as planned. Grade 3/4 neutropenia occurred in 66% of patients with 7.4% developing febrile neutropenia. Most neutropenic episodes (83%) occurred in the post-radiotherapy period during cycles 2 and 3 of ECF. Grade 3/4 gastrointestinal toxicity occurred in 28% of patients. In all, 35% of radiotherapy treatment plans contained protocol deviations that were satisfactorily amended before commencement of treatment. At median follow-up of 36 months, the 3-year overall survival rate was estimated at 61.6%. Conclusions: This adjuvant regimen using ECF before and after three-dimensional conformal chemoradiation is feasible and can be safely delivered in a cooperative group setting. A regimen similar to this is currently being compared with the INT0116 regimen in a National Cancer Institute-sponsored, randomized Phase III trial.« less

Recent advances in intensity modulated radiotherapy and proton therapy for esophageal cancer.

PubMed

Xi, Mian; Lin, Steven H

2017-07-01

Radiotherapy is an important component of the standard of care for esophageal cancer. In the past decades, significant improvements in the planning and delivery of radiation techniques have led to better dose conformity to the target volume and improved normal tissue sparing. Areas covered: This review focuses on the advances in radiotherapy techniques and summarizes the availably dosimetric and clinical outcomes of intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy, proton therapy, and four-dimensional radiotherapy for esophageal cancer, and discusses the challenges and future development of proton therapy. Expert commentary: Although three-dimensional conformal radiotherapy is the standard radiotherapy technique in esophageal cancer, the retrospectively comparative studies strongly suggest that the dosimetric advantage of IMRT over three-dimensional conformal radiotherapy can translate into improved clinical outcomes, despite the lack of prospective randomized evidence. As a novel form of conventional IMRT technique, volumetric modulated arc therapy can produce equivalent or superior dosimetric quality with significantly higher treatment efficiency in esophageal cancer. Compared with photon therapy, proton therapy has the potential to achieve further clinical improvement due to their physical properties; however, prospective clinical data, long-term results, and cost-effectiveness are needed.

Rapid prototyping raw models on the basis of high resolution computed tomography lung data for respiratory flow dynamics.

PubMed

Giesel, Frederik L; Mehndiratta, Amit; von Tengg-Kobligk, Hendrik; Schaeffer, A; Teh, Kevin; Hoffman, E A; Kauczor, Hans-Ulrich; van Beek, E J R; Wild, Jim M

2009-04-01

Three-dimensional image reconstruction by volume rendering and rapid prototyping has made it possible to visualize anatomic structures in three dimensions for interventional planning and academic research. Volumetric chest computed tomography was performed on a healthy volunteer. Computed tomographic images of the larger bronchial branches were segmented by an extended three-dimensional region-growing algorithm, converted into a stereolithography file, and used for computer-aided design on a laser sintering machine. The injection of gases for respiratory flow modeling and measurements using magnetic resonance imaging were done on a hollow cast. Manufacturing the rapid prototype took about 40 minutes and included the airway tree from trackea to segmental bronchi (fifth generation). The branching of the airways are clearly visible in the (3)He images, and the radial imaging has the potential to elucidate the airway dimensions. The results for flow patterns in the human bronchial tree using the rapid-prototype model with hyperpolarized helium-3 magnetic resonance imaging show the value of this model for flow phantom studies.

Image-guided robotic surgery.

PubMed

Marescaux, Jacques; Solerc, Luc

2004-06-01

Medical image processing leads to an improvement in patient care by guiding the surgical gesture. Three-dimensional models of patients that are generated from computed tomographic scans or magnetic resonance imaging allow improved surgical planning and surgical simulation that offers the opportunity for a surgeon to train the surgical gesture before performing it for real. These two preoperative steps can be used intra-operatively because of the development of augmented reality, which consists of superimposing the preoperative three-dimensional model of the patient onto the real intraoperative view. Augmented reality provides the surgeon with a view of the patient in transparency and can also guide the surgeon, thanks to the real-time tracking of surgical tools during the procedure. When adapted to robotic surgery, this tool tracking enables visual serving with the ability to automatically position and control surgical robotic arms in three dimensions. It is also now possible to filter physiologic movements such as breathing or the heart beat. In the future, by combining augmented reality and robotics, these image-guided robotic systems will enable automation of the surgical procedure, which will be the next revolution in surgery.

Reduced toxicity with equivalent outcomes using three-dimensional volumetric (3DV) image-based versus nonvolumetric point-based (NV) brachytherapy in a cervical cancer population.

PubMed

Thomas, Kimberly M; Maquilan, Genevieve; Stojadinovic, Strahinja; Medin, Paul; Folkert, Michael R; Albuquerque, Kevin

Brachytherapy (BT) techniques have historically used a two-dimensional nonvolumetric (NV) system involving dose prescribed to a point fixed in space. We compared dosimetric, toxicity, and oncologic outcomes for volumetric planning (3DV) versus CT point-based planning. Patients treated with external beam radiation therapy and high dose rate (HDR) intracavitary BT were included (n = 71). Patients planned with NV BT treated from 2009 to 2011 (n = 37) were compared to patients planned with 3DV BT treated from 2012 to 2014 (n = 34). Investigators delineated volumes for organs at risk clinical target volumes for the 2009-2011 NV cohort. Acute and chronic toxicity data were graded. The mean HDR clinical target volume D90 received in the NV and 3DV cohorts were significantly different (p < 0.001). The mean dose to point A was significantly higher in the NV cohort than in the 3DV cohort (p < 0.001). There were significantly more Grade 3 or higher gastrointestinal toxicities in the NV cohort (p = 0.048). There was a nonsignificant trend toward improved oncologic outcomes for patients undergoing CT-based planning. 3DV BT allows for a significant reduction of dose to critical structures, resulting in decreased gastrointestinal toxicity, while delivering noninferior doses to the high-risk clinical target volume. Outcomes were improved in the 3D cohort trending toward statistical significance. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Knowledge-based zonal grid generation for computational fluid dynamics

NASA Technical Reports Server (NTRS)

Andrews, Alison E.

1988-01-01

Automation of flow field zoning in two dimensions is an important step towards reducing the difficulty of three-dimensional grid generation in computational fluid dynamics. Using a knowledge-based approach makes sense, but problems arise which are caused by aspects of zoning involving perception, lack of expert consensus, and design processes. These obstacles are overcome by means of a simple shape and configuration language, a tunable zoning archetype, and a method of assembling plans from selected, predefined subplans. A demonstration system for knowledge-based two-dimensional flow field zoning has been successfully implemented and tested on representative aerodynamic configurations. The results show that this approach can produce flow field zonings that are acceptable to experts with differing evaluation criteria.

Three-dimensional echocardiography of congenital abnormalities of the left atrioventricular valve

PubMed Central

Rice, Kathryn

2015-01-01

Congenital abnormalities of the left atrioventricular (AV) valve are a significant diagnostic challenge. Traditionally, reliance has been placed on two-dimensional echocardiographic (2DE) imaging to guide recognition of the specific morphological features. Real-time 3DE can provide unique views of the left AV valve with the potential to improve understanding of valve morphology and function to facilitate surgical planning. This review illustrates the features of congenital abnormalities of the left AV valve assessed by 3DE. The similarities and differences in morphology between different lesions are described, both with respect to the valve itself and supporting chordal apparatus. The potential advantages as well as limitations of this technique in clinical practice are outlined. PMID:26693328

3D printing technology as innovative tool for math and geometry teaching applications

NASA Astrophysics Data System (ADS)

Huleihil, M.

2017-01-01

The industrial revolution and automation of production processes have changed the face of the world. Three dimensional (3D) printing has the potential to revolutionize manufacturing and further change methods of production toward allowing in increasing number of people to produce products at home. According to a recent OECD (see Backer [1]) publication, “…tapping into the next industrial revolution requires actions on many levels and in many different areas. In particular, unlocking the potential of emerging and enabling technologies requires policy development along a number of fronts, from commercialization to regulation and the supply of skills through education.” In this paper we discuss the role of schools and their responsibility to act as quickly as possible to design a plan of action that will prepare the future citizens to deal with this new reality. This requires planning of action in different directions and on different planes, such as labs, teachers, and curricula. 3D printing requires higher levels of thinking, innovation and creativity. It has the power to develop human imagination and give students the opportunity to visualize numbers, two- dimensional shapes, and three-dimensional objects. The combination of thinking, design, and production has immense power to increase motivation and satisfaction, with a highly probable increase in a student’s math and geometry achievements. The CAD system includes a measure tool which enables and alternative way for calculating properties of the objects under consideration and allows development of reflection and critical thinking. The research method was based on comparison between a reference group and a test group; it was found that intervention significantly improved the reflection abilities of 6th grade students in mathematics.

Value of three-dimensional volume rendering images in the assessment of the centrality index for preoperative planning in patients with renal masses.

PubMed

Sofia, C; Magno, C; Silipigni, S; Cantisani, V; Mucciardi, G; Sottile, F; Inferrera, A; Mazziotti, S; Ascenti, G

2017-01-01

To evaluate the precision of the centrality index (CI) measurement on three-dimensional (3D) volume rendering technique (VRT) images in patients with renal masses, compared to its standard measurement on axial images. Sixty-five patients with renal lesions underwent contrast-enhanced multidetector (MD) computed tomography (CT) for preoperative imaging. Two readers calculated the CI on two-dimensional axial images and on VRT images, measuring it in the plane that the tumour and centre of the kidney were lying in. Correlation and agreement of interobserver measurements and inter-method results were calculated using intraclass correlation (ICC) coefficients and the Bland-Altman method. Time saving was also calculated. The correlation coefficients were r=0.99 (p<0.05) and r=0.99 (p<0.05) for both the CI on axial and VRT images, with an ICC of 0.99, and 0.99, respectively. Correlation between the two methods of measuring the CI on VRT and axial CT images was r=0.99 (p<0.05). The two methods showed a mean difference of -0.03 (SD 0.13). Mean time saving per each examination with VRT was 45.5%. The present study showed that VRT and axial images produce almost identical values of CI, with the advantages of greater ease of execution and a time saving of almost 50% for 3D VRT images. In addition, VRT provides an integrated perspective that can better assist surgeons in clinical decision making and in operative planning, suggesting this technique as a possible standard method for CI measurement. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

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.

Needle path planning and steering in a three-dimensional non-static environment using two-dimensional ultrasound images

PubMed Central

Vrooijink, Gustaaf J.; Abayazid, Momen; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

2015-01-01

Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle). PMID:26279600

ECUT (Energy Conversion and Utilization Technologies) program: Biocatalysis project

NASA Technical Reports Server (NTRS)

Baresi, Larry

1989-01-01

The Annual Report presents the fiscal year (FY) 1988 research activities and accomplishments, for the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Division. The ECUT Biocatalysis Project is managed by the Jet Propulsion Laboratory, California Institute of Technology. The Biocatalysis Project is a mission-oriented, applied research and exploratory development activity directed toward resolution of the major generic technical barriers that impede the development of biologically catalyzed commercial chemical production. The approach toward achieving project objectives involves an integrated participation of universities, industrial companies and government research laboratories. The Project's technical activities were organized into three work elements: (1) The Molecular Modeling and Applied Genetics work element includes research on modeling of biological systems, developing rigorous methods for the prediction of three-dimensional (tertiary) protein structure from the amino acid sequence (primary structure) for designing new biocatalysis, defining kinetic models of biocatalyst reactivity, and developing genetically engineered solutions to the generic technical barriers that preclude widespread application of biocatalysis. (2) The Bioprocess Engineering work element supports efforts in novel bioreactor concepts that are likely to lead to substantially higher levels of reactor productivity, product yields and lower separation energetics. Results of work within this work element will be used to establish the technical feasibility of critical bioprocess monitoring and control subsystems. (3) The Bioprocess Design and Assessment work element attempts to develop procedures (via user-friendly computer software) for assessing the energy-economics of biocatalyzed chemical production processes, and initiation of technology transfer for advanced bioprocesses.

Novel branching particle method for tracking

NASA Astrophysics Data System (ADS)

Ballantyne, David J.; Chan, Hubert Y.; Kouritzin, Michael A.

2000-07-01

Particle approximations are used to track a maneuvering signal given only a noisy, corrupted sequence of observations, as are encountered in target tracking and surveillance. The signal exhibits nonlinearities that preclude the optimal use of a Kalman filter. It obeys a stochastic differential equation (SDE) in a seven-dimensional state space, one dimension of which is a discrete maneuver type. The maneuver type switches as a Markov chain and each maneuver identifies a unique SDE for the propagation of the remaining six state parameters. Observations are constructed at discrete time intervals by projecting a polygon corresponding to the target state onto two dimensions and incorporating the noise. A new branching particle filter is introduced and compared with two existing particle filters. The filters simulate a large number of independent particles, each of which moves with the stochastic law of the target. Particles are weighted, redistributed, or branched, depending on the method of filtering, based on their accordance with the current observation from the sequence. Each filter provides an approximated probability distribution of the target state given all back observations. All three particle filters converge to the exact conditional distribution as the number of particles goes to infinity, but differ in how well they perform with a finite number of particles. Using the exactly known ground truth, the root-mean-squared (RMS) errors in target position of the estimated distributions from the three filters are compared. The relative tracking power of the filters is quantified for this target at varying sizes, particle counts, and levels of observation noise.

ECUT (Energy Conversion and Utilization Technologies) program: Biocatalysis project

NASA Astrophysics Data System (ADS)

Baresi, Larry

1989-03-01

The Annual Report presents the fiscal year (FY) 1988 research activities and accomplishments, for the Biocatalysis Project of the U.S. Department of Energy, Energy Conversion and Utilization Technologies (ECUT) Division. The ECUT Biocatalysis Project is managed by the Jet Propulsion Laboratory, California Institute of Technology. The Biocatalysis Project is a mission-oriented, applied research and exploratory development activity directed toward resolution of the major generic technical barriers that impede the development of biologically catalyzed commercial chemical production. The approach toward achieving project objectives involves an integrated participation of universities, industrial companies and government research laboratories. The Project's technical activities were organized into three work elements: (1) The Molecular Modeling and Applied Genetics work element includes research on modeling of biological systems, developing rigorous methods for the prediction of three-dimensional (tertiary) protein structure from the amino acid sequence (primary structure) for designing new biocatalysis, defining kinetic models of biocatalyst reactivity, and developing genetically engineered solutions to the generic technical barriers that preclude widespread application of biocatalysis. (2) The Bioprocess Engineering work element supports efforts in novel bioreactor concepts that are likely to lead to substantially higher levels of reactor productivity, product yields and lower separation energetics. Results of work within this work element will be used to establish the technical feasibility of critical bioprocess monitoring and control subsystems. (3) The Bioprocess Design and Assessment work element attempts to develop procedures (via user-friendly computer software) for assessing the energy-economics of biocatalyzed chemical production processes, and initiation of technology transfer for advanced bioprocesses.

Virtual surgical planning in endoscopic skull base surgery.

PubMed

Haerle, Stephan K; Daly, Michael J; Chan, Harley H L; Vescan, Allan; Kucharczyk, Walter; Irish, Jonathan C

2013-12-01

Skull base surgery (SBS) involves operative tasks in close proximity to critical structures in a complex three-dimensional (3D) anatomy. The aim was to investigate the value of virtual planning (VP) based on preoperative magnetic resonance imaging (MRI) for surgical planning in SBS and to compare the effects of virtual planning with 3D contours between the expert and the surgeon in training. Retrospective analysis. Twelve patients with manually segmented anatomical structures based on preoperative MRI were evaluated by eight surgeons in a randomized order using a validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire. Multivariate analysis revealed significant reduction of workload when using VP (P<.0001) compared to standard planning. Further, it showed that the experience level of the surgeon had a significant effect on the NASA-TLX differences (P<.05). Additional subanalysis did not reveal any significant findings regarding which type of surgeon benefits the most (P>.05). Preoperative anatomical segmentation with virtual surgical planning using contours in endoscopic SBS significantly reduces the workload for the expert and the surgeon in training. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

77 FR 71396 - Humboldt-Toiyabe National Forest; Nevada and California Greater Sage Grouse Bi-State Distinct...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-30

... decision makers as to render them inadequate to ameliorate the threats to the Bi-State DPS''. The major... three records of decision. The development of this EIS will be coordinated across management units of..., but precluded'' Endangered Species Act (ESA) listing petition decision for the Greater Sage grouse Bi...

Aortic valve replacement in a Jehovah’s Witness: a case of multi-disciplinary clinical management for bloodless surgery

PubMed Central

Park, John Jungpa; Lang, Christopher C; Manson, Lynn; Brackenbury, Edward T

2012-01-01

An 81-year-old female Jehovah’s Witness (JW) patient with severe aortic stenosis required aortic valve replacement (AVR). However, the patient’s religious beliefs precluded the use of primary blood components. Since the definitive treatment of AVR required bloodless open heart surgery, careful peri-operative plans were set forth by a multi-disciplinary team involving the cardiothoracic surgeon, haematologist and anaesthetist. The patient went on to successfully recover postoperatively. This case highlights: 1) The importance of carefully navigating through the most recent clinical and ethical protocol involved in the surgical management of JW’s. 2) The importance of preparing individually tailored pre, intra and postoperative plans that are delivered through a multi-disciplinary clinical team to ensure the best and safest possible outcomes. PMID:22665474

Automated patient identification and localization error detection using 2-dimensional to 3-dimensional registration of kilovoltage x-ray setup images.

PubMed

Lamb, James M; Agazaryan, Nzhde; Low, Daniel A

2013-10-01

To determine whether kilovoltage x-ray projection radiation therapy setup images could be used to perform patient identification and detect gross errors in patient setup using a computer algorithm. Three patient cohorts treated using a commercially available image guided radiation therapy (IGRT) system that uses 2-dimensional to 3-dimensional (2D-3D) image registration were retrospectively analyzed: a group of 100 cranial radiation therapy patients, a group of 100 prostate cancer patients, and a group of 83 patients treated for spinal lesions. The setup images were acquired using fixed in-room kilovoltage imaging systems. In the prostate and cranial patient groups, localizations using image registration were performed between computed tomography (CT) simulation images from radiation therapy planning and setup x-ray images corresponding both to the same patient and to different patients. For the spinal patients, localizations were performed to the correct vertebral body, and to an adjacent vertebral body, using planning CTs and setup x-ray images from the same patient. An image similarity measure used by the IGRT system image registration algorithm was extracted from the IGRT system log files and evaluated as a discriminant for error detection. A threshold value of the similarity measure could be chosen to separate correct and incorrect patient matches and correct and incorrect vertebral body localizations with excellent accuracy for these patient cohorts. A 10-fold cross-validation using linear discriminant analysis yielded misclassification probabilities of 0.000, 0.0045, and 0.014 for the cranial, prostate, and spinal cases, respectively. An automated measure of the image similarity between x-ray setup images and corresponding planning CT images could be used to perform automated patient identification and detection of localization errors in radiation therapy treatments. Copyright © 2013 Elsevier Inc. All rights reserved.

Three-dimensional modelling and three-dimensional printing in pediatric and congenital cardiac surgery.

PubMed

Kiraly, Laszlo

2018-04-01

Three-dimensional (3D) modelling and printing methods greatly support advances in individualized medicine and surgery. In pediatric and congenital cardiac surgery, personalized imaging and 3D modelling presents with a range of advantages, e.g., better understanding of complex anatomy, interactivity and hands-on approach, possibility for preoperative surgical planning and virtual surgery, ability to assess expected results, and improved communication within the multidisciplinary team and with patients. 3D virtual and printed models often add important new anatomical findings and prompt alternative operative scenarios. For the lack of critical mass of evidence, controlled randomized trials, however, most of these general benefits remain anecdotal. For an individual surgical case-scenario, prior knowledge, preparedness and possibility of emulation are indispensable in raising patient-safety. It is advocated that added value of 3D printing in healthcare could be raised by establishment of a multidisciplinary centre of excellence (COE). Policymakers, research scientists, clinicians, as well as health care financers and local entrepreneurs should cooperate and communicate along a legal framework and established scientific guidelines for the clinical benefit of patients, and towards financial sustainability. It is expected that besides the proven utility of 3D printed patient-specific anatomical models, 3D printing will have a major role in pediatric and congenital cardiac surgery by providing individually customized implants and prostheses, especially in combination with evolving techniques of bioprinting.

Patient-specific 3D printing simulation to guide complex coronary intervention.

PubMed

Oliveira-Santos, Manuel; Oliveira Santos, Eduardo; Marinho, Ana Vera; Leite, Luís; Guardado, Jorge; Matos, Vítor; Pego, Guilherme Mariano; Marques, João Silva

2018-05-07

The field of three-dimensional printing applied to patient-specific simulation is evolving as a tool to enhance intervention results. We report the first case of a fully simulated percutaneous coronary intervention in a three-dimensional patient-specific model to guide treatment. An 85-year-old female presented with symptomatic in-stent restenosis in the ostial circumflex and was scheduled for percutaneous coronary intervention. Considering the complexity of the anatomy, patient setting and intervention technique, we elected to replicate the coronary anatomy using a three-dimensional model. In this way, we simulated the intervention procedure beforehand in the catheterization laboratory using standard materials. The procedure was guided by optical coherence tomography, with pre-dilatation of the lesion, implantation of a single drug-eluting stent in the ostial circumflex and kissing balloon inflation to the left anterior descending artery and circumflex. Procedural steps were replicated in the real patient's treatment, with remarkable parallelism in angiographic outcome and luminal gain at intracoronary imaging. In this proof-of-concept report, we show that patient-specific simulation is feasible to guide the treatment strategy of complex coronary artery disease. It enables the surgical team to plan and practice the procedure beforehand, and possibly predict complications and gain confidence. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Three-dimensional modelling and three-dimensional printing in pediatric and congenital cardiac surgery

PubMed Central

2018-01-01

Three-dimensional (3D) modelling and printing methods greatly support advances in individualized medicine and surgery. In pediatric and congenital cardiac surgery, personalized imaging and 3D modelling presents with a range of advantages, e.g., better understanding of complex anatomy, interactivity and hands-on approach, possibility for preoperative surgical planning and virtual surgery, ability to assess expected results, and improved communication within the multidisciplinary team and with patients. 3D virtual and printed models often add important new anatomical findings and prompt alternative operative scenarios. For the lack of critical mass of evidence, controlled randomized trials, however, most of these general benefits remain anecdotal. For an individual surgical case-scenario, prior knowledge, preparedness and possibility of emulation are indispensable in raising patient-safety. It is advocated that added value of 3D printing in healthcare could be raised by establishment of a multidisciplinary centre of excellence (COE). Policymakers, research scientists, clinicians, as well as health care financers and local entrepreneurs should cooperate and communicate along a legal framework and established scientific guidelines for the clinical benefit of patients, and towards financial sustainability. It is expected that besides the proven utility of 3D printed patient-specific anatomical models, 3D printing will have a major role in pediatric and congenital cardiac surgery by providing individually customized implants and prostheses, especially in combination with evolving techniques of bioprinting. PMID:29770294

Multipoint Geospace Science in 3D: The Paired Ionosphere-Thermosphere Orbiters(PITO) Mission

NASA Technical Reports Server (NTRS)

Clemmons, J.; Walterscheid, R.; Nigg, D.; Judnick, D.; Lang, J.; Spann, J.

2010-01-01

The science enabled by the Paired Ionosphere-Thermosphere Orbiters (PITO) mission is described and discussed. PITO has been designed to provide the concurrent, three-dimensional, multipoint measurements needed to advance geospace science while staying within a stringent resource envelope. The mission utilizes a pair of orbiting vehicles in eccentric, high-inclination, coplanar orbits. The orbits have arguments of perigee that differ by 180 degrees and are phased such that one vehicle is at perigee (200 km) while the second is at apogee (2000 km). Half an orbit later, the vehicles switch positions. Three complementary types of measurements exploit this scenario: local, in-situ measurements on both satellites, two-dimensional imaging from the higher satellite, and vertical sounders. The main idea is that two-dimensional context information for the low-altitude measurements is obtained by the high altitude imagers, while information on the third dimension is provided by vertical profiling. Such an observation system is capable of providing elements of global coverage, regional coverage, and concurrent coverage in three dimensions. Science goals are presented, as are the results of a detailed implementation plan, including several trade studies on key elements of the mission. The conclusion is that the mission would enable significant new understanding of the ionosphere-thermosphere system within a resource envelope that is consistent with that of NASA's Medium Explorer (MIDEX) line of science missions.

A novel approach for determining three-dimensional acetabular orientation: results from two hundred subjects.

PubMed

Higgins, Sean W; Spratley, E Meade; Boe, Richard A; Hayes, Curtis W; Jiranek, William A; Wayne, Jennifer S

2014-11-05

The inherently complex three-dimensional morphology of both the pelvis and acetabulum create difficulties in accurately determining acetabular orientation. Our objectives were to develop a reliable and accurate methodology for determining three-dimensional acetabular orientation and to utilize it to describe relevant characteristics of a large population of subjects without apparent hip pathology. High-resolution computed tomography studies of 200 patients previously receiving pelvic scans for indications not related to orthopaedic conditions were selected from our institution's database. Three-dimensional models of each osseous pelvis were generated to extract specific anatomical data sets. A novel computational method was developed to determine standard measures of three-dimensional acetabular orientation within an automatically identified anterior pelvic plane reference frame. Automatically selected points on the osseous ridge of the acetabulum were used to generate a best-fit plane for describing acetabular orientation. Our method showed excellent interobserver and intraobserver agreement (an intraclass correlation coefficient [ICC] of >0.999) and achieved high levels of accuracy. A significant difference between males and females in both anteversion (average, 3.5°; 95% confidence interval [CI], 1.9° to 5.1° across all angular definitions; p < 0.0001) and inclination (1.4°; 95% CI, 0.6° to 2.3° for anatomic angular definition; p < 0.002) was observed. Intrapatient asymmetry in anatomic measures showed bilateral differences in anteversion (maximum, 12.1°) and in inclination (maximum, 10.9°). Significant differences in acetabular orientation between the sexes can be detected only with accurate measurements that account for the entire acetabulum. While a wide range of interpatient acetabular orientations was observed, the majority of subjects had acetabula that were relatively symmetrical in both inclination and anteversion. A highly accurate and reproducible method for determining the orientation of the acetabulum's aperture will benefit both surgeons and patients, by further refining the distinctions between normal and abnormal hip characteristics. Enhanced understanding of the acetabulum could be useful in the diagnostic, planning, and execution stages for surgical procedures of the hip or in advancing the design of new implant systems. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Modeling Three-Dimensional Flow in Confined Aquifers by Superposition of Both Two- and Three-Dimensional Analytic Functions

NASA Astrophysics Data System (ADS)

Haitjema, Henk M.

1985-10-01

A technique is presented to incorporate three-dimensional flow in a Dupuit-Forchheimer model. The method is based on superposition of approximate analytic solutions to both two- and three-dimensional flow features in a confined aquifer of infinite extent. Three-dimensional solutions are used in the domain of interest, while farfield conditions are represented by two-dimensional solutions. Approximate three- dimensional solutions have been derived for a partially penetrating well and a shallow creek. Each of these solutions satisfies the condition that no flow occurs across the confining layers of the aquifer. Because of this condition, the flow at some distance of a three-dimensional feature becomes nearly horizontal. Consequently, remotely from a three-dimensional feature, its three-dimensional solution is replaced by a corresponding two-dimensional one. The latter solution is trivial as compared to its three-dimensional counterpart, and its use greatly enhances the computational efficiency of the model. As an example, the flow is modeled between a partially penetrating well and a shallow creek that occur in a regional aquifer system.

National Aeronautics and Space Administration FY 02 Revised Final Annual Performance Plan

DTIC Science & Technology

2002-01-01

years ago led to the extinction of dinosaurs and cleared the way for the rise of mammals. An even greater impact more than 200 million years ago led...extinction of dinosaurs and cleared the way for the rise of mammals. An even greater impact more than 200 million years ago led to the extinction...cellular biotechnology. • Prepare ISS research investigations in protein crystallization and three-dimensional tissue culture. PP BPR-6 Public

The Potential Impact of Collaborative and Three-Dimensional Imaging Technology on SHIPMAIN Fleet Modernization Plan

DTIC Science & Technology

2008-01-01

Degree in Business Administration and was commissioned an Ensign in April of 2002 via the Inservice Procurement Program. LT Seaman reported for duty as...Florida for duty as an instructor/trainer and ran the Emergency Medical Technician training program and served as an Affiliate Faculty for the American...Heart Association’s Basic Life Support Program. Through the Inservice Procurement Program, he was commissioned as an Ensign in the Medical Service

The Potential Impact of Collaborative and Three-dimensional Imaging Technology on SHIPMAIN Fleet Modernization Plan

DTIC Science & Technology

2007-10-26

Ensign in April of 2002 via the Inservice Procurement Program. LT Seaman reported for duty as a staff hospital corpsman assigned to Naval Hospital Camp...Emergency Medical Technician training program and served as an Affiliate Faculty for the American Heart Association’s Basic Life Support Program. Through...the Inservice Procurement Program, he was commissioned as an Ensign in the Medical Service Corps in April of 2002 and completed Officer

A Stochastic Approach to Path Planning in the Weighted-Region Problem

DTIC Science & Technology

1991-03-01

polynomial time. However, the polyhedrons in this three-dimensional obstacle-avoidance problem are all obstacles (i.e. travel is not permitted within...them). Therefore, optimal paths tend to avoid their vertices, and settle into closest approach tangents across polyhedron edges. So, in a sense...intersection update map database with new vertex for this edge 3. IF (C1 > D) and (C2 > D) THEN edge intersects ellipse at two points OR edge is

Computer Programs For Automated Welding System

NASA Technical Reports Server (NTRS)

Agapakis, John E.

1993-01-01

Computer programs developed for use in controlling automated welding system described in MFS-28578. Together with control computer, computer input and output devices and control sensors and actuators, provide flexible capability for planning and implementation of schemes for automated welding of specific workpieces. Developed according to macro- and task-level programming schemes, which increases productivity and consistency by reducing amount of "teaching" of system by technician. System provides for three-dimensional mathematical modeling of workpieces, work cells, robots, and positioners.

Ripples in The Soil

NASA Technical Reports Server (NTRS)

2004-01-01

This is a three-dimensional stereo anaglyph of an image taken by the front navigation camera onboard the Mars Exploration Rover Spirit, showing an interesting patch of rippled soil. Spirit took this image on sol 37 (Feb. 9, 2004) after completing the longest drive ever made by a rover on another planet - 21.2 meters (69.6 feet). On sol 38 scientists plan to investigate this interesting location with the microscopic imager and Moessbauer spectrometer on Spirit's instrument deployment device.

Endodontic Management of a Maxillary Lateral Incisor with 4 Root Canals and a Dens Invaginatus Tract.

PubMed

Nosrat, Ali; Schneider, S Craig

2015-07-01

Dens invaginatus (DI) is associated with complex internal anatomy. This article represents a maxillary lateral incisor with 5 root canals including DI. The treatment was planned and performed using cone-beam computed tomographic (CBCT) imaging. After clinical and radiographic evaluations, tooth #7 was diagnosed with DI and pulp necrosis with symptomatic apical periodontitis. Periapical radiographs of the tooth showed 2 roots and complex internal anatomy. CBCT evaluation revealed tooth #7 had 5 separate canals (4 root canals and 1 DI canal extending through the root to the periodontal ligament), communication between DI and the root canal system, and severe and multiple curvatures of the palatal canals. Root canal treatment was completed in 2 visits. Modified access openings were required to safely treat the dilacerated palatal canals. At the 6-month re-evaluation, the patient reported he had remained asymptomatic and his tooth had remained functional since the treatment was completed. Clinical examination showed tooth #7 had no sensitivity to percussion or palpation, probe depths within normal limits (≤3 mm), and no mobility. Radiographic assessment of the tooth showed significant osseous healing of the preoperative lesion. Three-dimensional imaging is a valuable tool for endodontic management of teeth with complex internal anatomy. Three-dimensional imaging is recommended for evaluating and treatment planning cases with DI. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Spatial interpretation of NASA's Marshall Space Flight Center Payload Operations Control Center using virtual reality technology

NASA Technical Reports Server (NTRS)

Lindsey, Patricia F.

1993-01-01

In its search for higher level computer interfaces and more realistic electronic simulations for measurement and spatial analysis in human factors design, NASA at MSFC is evaluating the functionality of virtual reality (VR) technology. Virtual reality simulation generates a three dimensional environment in which the participant appears to be enveloped. It is a type of interactive simulation in which humans are not only involved, but included. Virtual reality technology is still in the experimental phase, but it appears to be the next logical step after computer aided three-dimensional animation in transferring the viewer from a passive to an active role in experiencing and evaluating an environment. There is great potential for using this new technology when designing environments for more successful interaction, both with the environment and with another participant in a remote location. At the University of North Carolina, a VR simulation of a the planned Sitterson Hall, revealed a flaw in the building's design that had not been observed during examination of the more traditional building plan simulation methods on paper and on computer aided design (CAD) work station. The virtual environment enables multiple participants in remote locations to come together and interact with one another and with the environment. Each participant is capable of seeing herself and the other participants and of interacting with them within the simulated environment.

Numerical optimization of three-dimensional coils for NSTX-U

NASA Astrophysics Data System (ADS)

Lazerson, S. A.; Park, J.-K.; Logan, N.; Boozer, A.

2015-10-01

A tool for the calculation of optimal three-dimensional (3D) perturbative magnetic fields in tokamaks has been developed. The IPECOPT code builds upon the stellarator optimization code STELLOPT to allow for optimization of linear ideal magnetohydrodynamic perturbed equilibrium (IPEC). This tool has been applied to NSTX-U equilibria, addressing which fields are the most effective at driving NTV torques. The NTV torque calculation is performed by the PENT code. Optimization of the normal field spectrum shows that fields with n  =  1 character can drive a large core torque. It is also shown that fields with n  =  3 features are capable of driving edge torque and some core torque. Coil current optimization (using the planned in-vessel and existing RWM coils) on NSTX-U suggest the planned coils set is adequate for core and edge torque control. Comparison between error field correction experiments on DIII-D and the optimizer show good agreement. Notice: This manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the U.S. Department of Energy. The publisher, by accepting the article for publication acknowledges, that the United States Government retains a non-exclusive,paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

The Application of Three-Dimensional Surface Imaging System in Plastic and Reconstructive Surgery.

PubMed

Li, Yanqi; Yang, Xin; Li, Dong

2016-02-01

Three-dimensional (3D) surface imaging system has gained popularity worldwide in clinical application. Unlike computed tomography and magnetic resonance imaging, it has the ability to capture 3D images with both shape and texture information. This feature has made it quite useful for plastic surgeons. This review article is mainly focusing on demonstrating the current status and analyzing the future of the application of 3D surface imaging systems in plastic and reconstructive surgery.Currently, 3D surface imaging system is mainly used in plastic and reconstructive surgery to help improve the reliability of surgical planning and assessing surgical outcome objectively. There have already been reports of its using on plastic and reconstructive surgery from head to toe. Studies on facial aging process, online applications development, and so on, have also been done through the use of 3D surface imaging system.Because different types of 3D surface imaging devices have their own advantages and disadvantages, a basic knowledge of their features is required and careful thought should be taken to choose the one that best fits a surgeon's demand.In the future, by integrating with other imaging tools and the 3D printing technology, 3D surface imaging system will play an important role in individualized surgical planning, implants production, meticulous surgical simulation, operative techniques training, and patient education.

Planning surgical reconstruction in Treacher-Collins syndrome using virtual simulation.

PubMed

Nikkhah, Dariush; Ponniah, Allan; Ruff, Cliff; Dunaway, David

2013-11-01

Treacher-Collins syndrome is a rare autosomal dominant condition of varying phenotypic expression. The surgical correction in this syndrome is difficult, and the approach varies between craniofacial departments worldwide. The authors aimed to design standardized tools for planning orbitozygomatic and mandibular reconstruction in Treacher-Collins syndrome using geometric morphometrics. The Great Ormond Street Hospital database was retrospectively identified for patients with Treacher-Collins syndrome. Thirteen children (aged 2 to 15 years) who had suitable preoperative three-dimensional computed tomographic head scans were included. Six Treacher-Collins syndrome three-dimensional computed tomographic head scans were quantitatively compared using a template of 96 anatomically defined landmarks to 26 age-matched normal dry skulls. Thin-plate spline videos illustrated the characteristic deformities of retromicrognathia and maxillary and orbitozygomatic hypoplasia in the Treacher-Collins syndrome population. Geometric morphometrics was used in the virtual reconstruction of the orbitozygomatic and mandibular region in Treacher-Collins syndrome patients. Intrarater and interrater reliability of the landmarks was acceptable and within a standard deviation of less than 1 mm on 97 percent and 100 percent of 10 repeated scans, respectively. Virtual normalization of the Treacher-Collins syndrome skull effectively describes characteristic skeletal deformities and provides a useful guide to surgical reconstruction. Size-matched stereolithographic templates derived from thin-plate spline warps can provide effective intraoperative templates for zygomatic and mandibular reconstruction in the Treacher-Collins syndrome patient. Diagnostic, V.

Orbit Stability of OSIRIS-REx in the Vicinity of Bennu Using a High-Fidelity Solar Radiation Model

NASA Technical Reports Server (NTRS)

Williams, Trevor; Hughes, Kyle; Mashiku, Alinda; Longuski, James

2015-01-01

The OSIRIS-REx mission (Origins Spectral Interpretation Resource Identification Security Regolith EXPlorer) is an asteroid sample return mission to Bennu (RQ36) that is scheduled to launch in 2016. The planned science operations precluding the small retrieval involve operations in terminator orbits (orbit plane is perpendicular to the sun). Over longer durations the solar radiation pressure (SRP) perturbs the orbit causing it to precess. Our work involves: modeling high fidelity SRP model to capture the perturbations during attitude changes; design a stable orbit from the high fidelity models to analyze the stability over time.

Printed three-dimensional anatomic templates for virtual preoperative planning before reconstruction of old pelvic injuries: initial results.

PubMed

Wu, Xin-Bao; Wang, Jun-Qiang; Zhao, Chun-Peng; Sun, Xu; Shi, Yin; Zhang, Zi-An; Li, Yu-Neng; Wang, Man-Yi

2015-02-20

Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy, difficult-to-access surgical sites, and the relatively low incidence of such cases. Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture. The goal of this study was to assess the use of three-dimensional (3D) printing techniques for surgical management of old pelvic fractures. First, 16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data. Next, nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models. The pelvic injuries were all type C, and the average time from injury to reconstruction was 11 weeks (range: 8-17 weeks). The workflow consisted of: (1) Printing patient-specific bone models based on preoperative computed tomography (CT) scans, (2) virtual fracture reduction using the printed 3D anatomic template, (3) virtual fracture fixation using Kirschner wires, and (4) preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation. These models aided communication between surgical team members during the procedure. This technique was validated by comparing the preoperative planning to the intraoperative procedure. The accuracy of the 3D printed models was within specification. Production of a model from standard CT DICOM data took 7 hours (range: 6-9 hours). Preoperative planning using the 3D printed models was feasible in all cases. Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases. The patients were followed for 3-29 months (median: 5 months). The fracture healing time was 9-17 weeks (mean: 10 weeks). No delayed incision healing, wound infection, or nonunions occurred. The results were excellent in two cases, good in five, and poor in two based on the Majeed score. The 3D printing planning technique for pelvic surgery was successfully integrated into a clinical workflow to improve patient-specific preoperative planning by providing a visual and haptic model of the injury and allowing patient-specific adaptation of each osteosynthesis implant to the virtually reduced pelvis.

Space Studies Board Annual Report, 2005

NASA Technical Reports Server (NTRS)

2005-01-01

The National Academy of Sciences (NAS) was chartered by Congress, under the leadership of President Abraham Lincoln, to provide scientific and technical advice to the government of the United States. Over the years, the advisory program of the institution has expanded, leading to the establishment of the National Academy of Engineering (NAE) and the Institute of Medicine, and of the National Research Council (NRC), the operational arm of the National Academies. The original charter of the Space Science Board was established in June 1958, three months before NASA opened its doors. The Space Science Board and its successor, the Space Studies Board (SSB), have provided expert external and independent scientific and programmatic advice to NASA on a continuous basis from NASA's inception until the present. The Board has also provided such advice to other agencies, including the National Oceanic and Atmospheric Administration, the National Science Foundation, the U.S. Geological Survey, and the Department of Defense, and responds to requests from Congress. Early in 2005, the leadership of NASA changed, and with it new emphases emerged. Some of the early interpretations of the 2004 Vision for Space Exploration, in which only certain aspects of space science were encouraged, disappeared and a broader mandate for science emerged. But what also emerged was fiscal reality, which precluded many of the exciting activities that were planned for NASA's science programs. In this environment of change, there has been a continuing need to evaluate NASA's plans against the strategies for science that have been laid down in the various NRC decadal surveys, and to assist NASA in determining how best to proceed given the reduced level of resources it will have. Coupled with this has been a continuing need to provide Congress with the assessments of NASA's plans that it requests.

A novel approach for planning orthognathic surgery: the integration of dental casts into three-dimensional printed mandibular models.

PubMed

Ayoub, A F; Rehab, M; O'Neil, M; Khambay, B; Ju, X; Barbenel, J; Naudi, K

2014-04-01

A method of producing a composite model consisting of a three-dimensional printed mandible bearing plaster teeth is presented. Printed models were obtained from cone beam computed tomograms (CBCT) of dry human mandibles. The plaster casts of the teeth were obtained from impressions of the teeth of the dry mandibles. The distorted teeth of the printed models were removed and replaced by the plaster casts of the teeth using a simple transfer jig. The accuracy of the composite models obtained from six mandibles was assessed from laser scans. The scans of the dry mandibles and the composite models were superimposed and the magnitude of the discrepancies at six points on the dentition and six on the mandible were obtained. It was concluded that the errors of the method were small enough to be clinically significant. The use of the composite models is illustrated in two clinical cases. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

A Computational/Experimental Platform for Investigating Three-Dimensional Puzzle Solving of Comminuted Articular Fractures

PubMed Central

Thomas, Thaddeus P.; Anderson, Donald D.; Willis, Andrew R.; Liu, Pengcheng; Frank, Matthew C.; Marsh, J. Lawrence; Brown, Thomas D.

2011-01-01

Reconstructing highly comminuted articular fractures poses a difficult surgical challenge, akin to solving a complicated three-dimensional (3D) puzzle. Pre-operative planning using CT is critically important, given the desirability of less invasive surgical approaches. The goal of this work is to advance 3D puzzle solving methods toward use as a pre-operative tool for reconstructing these complex fractures. Methodology for generating typical fragmentation/dispersal patterns was developed. Five identical replicas of human distal tibia anatomy, were machined from blocks of high-density polyetherurethane foam (bone fragmentation surrogate), and were fractured using an instrumented drop tower. Pre- and post-fracture geometries were obtained using laser scans and CT. A semi-automatic virtual reconstruction computer program aligned fragment native (non-fracture) surfaces to a pre-fracture template. The tibias were precisely reconstructed with alignment accuracies ranging from 0.03-0.4mm. This novel technology has potential to significantly enhance surgical techniques for reconstructing comminuted intra-articular fractures, as illustrated for a representative clinical case. PMID:20924863

Results of tests performed on the Acoustic Quiet Flow Facility Three-Dimensional Model Tunnel: Report on the Modified D.S.M.A. Design

NASA Technical Reports Server (NTRS)

Barna, P. S.

1996-01-01

Numerous tests were performed on the original Acoustic Quiet Flow Facility Three-Dimensional Model Tunnel, scaled down from the full-scale plans. Results of tests performed on the original scale model tunnel were reported in April 1995, which clearly showed that this model was lacking in performance. Subsequently this scale model was modified to attempt to possibly improve the tunnel performance. The modifications included: (a) redesigned diffuser; (b) addition of a collector; (c) addition of a Nozzle-Diffuser; (d) changes in location of vent-air. Tests performed on the modified tunnel showed a marked improvement in performance amounting to a nominal increase of pressure recovery in the diffuser from 34 percent to 54 percent. Results obtained in the tests have wider application. They may also be applied to other tunnels operating with an open test section not necessarily having similar geometry as the model under consideration.

A national facility for biological cryo-electron microscopy

PubMed Central

Saibil, Helen R.; Grünewald, Kay; Stuart, David I.

2015-01-01

Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback. PMID:25615867

Robot-assisted three-dimensional registration for cochlear implant surgery using a common-path swept-source optical coherence tomography probe

NASA Astrophysics Data System (ADS)

Gurbani, Saumya S.; Wilkening, Paul; Zhao, Mingtao; Gonenc, Berk; Cheon, Gyeong Woo; Iordachita, Iulian I.; Chien, Wade; Taylor, Russell H.; Niparko, John K.; Kang, Jin U.

2014-05-01

Cochlear implantation offers the potential to restore sensitive hearing in patients with severe to profound deafness. However, surgical placement of the electrode array within the cochlea can produce trauma to sensorineural components, particularly if the initial turn of the cochlea is not successfully navigated as the array is advanced. In this work, we present a robot-mounted common-path swept-source optical coherence tomography endoscopic platform for three-dimensional (3-D) optical coherence tomography (OCT) registration and preoperative surgical planning for cochlear implant surgery. The platform is composed of a common-path 600-μm diameter fiber optic rotary probe attached to a five degrees of freedom robot capable of 1 μm precision movement. The system is tested on a dry fixed ex vivo human temporal bone, and we demonstrate the feasibility of a 3-D OCT registration of the cochlea to accurately describe the spatial and angular profiles of the canal formed by the scala tympani into the first cochlear turn.

Influence of specific obsessive-compulsive symptom dimensions on strategic planning in patients with obsessive-compulsive disorder.

PubMed

Pinto, Paula Sanders Pereira; Iego, Sandro; Nunes, Samantha; Menezes, Hemanny; Mastrorosa, Rosana Sávio; Oliveira, Irismar Reis de; Rosário, Maria Conceição do

2011-03-01

This study investigates obsessive-compulsive disorder patients in terms of strategic planning and its association with specific obsessive-compulsive symptom dimensions. We evaluated 32 obsessive-compulsive disorder patients. Strategic planning was assessed by the Rey-Osterrieth Complex Figure Test, and the obsessive-compulsive dimensions were assessed by the Dimensional Yale-Brown Obsessive-Compulsive Scale. In the statistical analyses, the level of significance was set at 5%. We employed linear regression, including age, intelligence quotient, number of comorbidities, the Yale-Brown Obsessive-Compulsive Scale score, and the Dimensional Yale-Brown Obsessive-Compulsive Scale. The Dimensional Yale-Brown Obsessive-Compulsive Scale "worst-ever" score correlated significantly with the planning score on the copy portion of the Rey-Osterrieth Complex Figure Test (r = 0.4, p = 0.04) and was the only variable to show a significant association after linear regression (β = 0.55, t = 2.1, p = 0.04). Compulsive hoarding correlated positively with strategic planning (r = 0.44, p = 0.03). None of the remaining symptom dimensions presented any significant correlations with strategic planning. We found the severity of obsessive-compulsive symptoms to be associated with strategic planning. In addition, there was a significant positive association between the planning score on the copy portion of the Rey-Osterrieth Complex Figure Test copy score and the hoarding dimension score on the Dimensional Yale-Brown Obsessive-Compulsive Scale. Our results underscore the idea that obsessive-compulsive disorder is a heterogeneous disorder and suggest that the hoarding dimension has a specific neuropsychological profile. Therefore, it is important to assess the peculiarities of each obsessive-compulsive symptom dimension.

Three-Dimensional Analysis of the Ear Morphology.

PubMed

Modabber, Ali; Galster, Helmut; Peters, Florian; Möhlhenrich, Stephan Christian; Kniha, Kristian; Knobe, Matthias; Hölzle, Frank; Ghassemi, Alireza

2018-06-01

For surgical treatment of the face, detailed surgical planning is necessary to avoid later unaesthetic results. Most of the studies in the literature concentrate on the ears' anatomy during childhood and adolescence. Nearly no study evaluates the anatomy of ears of people aged 50 or older. It was our aim to measure and evaluate the ear's anatomy in Caucasians between the ages of 21 and 65. Three-dimensional scans of 240 volunteers were taken. The subjects were divided into groups of males and females and each of them into three groups by age (21-35, 36-50, 51-65). Landmarks were placed in these scans. Distances, relations and angles between them were recorded. The distance between the subaurale and superaurale significantly increases (p < 0.001) during the aging process in males and females. Also, the width of the ear, measured between the preaurale and postaurale, significantly increased (p = 0.007) with advancing age. When the length of the ear is divided into four parts by anatomical landmarks, it extended the most in the lower quadrant with increasing subject age. The ear of Caucasians does not stop changing its shape during adulthood. Even after the body has stopped growing, the ear still does. With the measured values in this study, it should be possible for the surgeon to plan the operation in advance and achieve satisfactory aesthetic outcomes. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Kinematic state estimation and motion planning for stochastic nonholonomic systems using the exponential map

PubMed Central

Park, Wooram; Liu, Yan; Zhou, Yu; Moses, Matthew; Chirikjian, Gregory S.

2010-01-01

SUMMARY A nonholonomic system subjected to external noise from the environment, or internal noise in its own actuators, will evolve in a stochastic manner described by an ensemble of trajectories. This ensemble of trajectories is equivalent to the solution of a Fokker–Planck equation that typically evolves on a Lie group. If the most likely state of such a system is to be estimated, and plans for subsequent motions from the current state are to be made so as to move the system to a desired state with high probability, then modeling how the probability density of the system evolves is critical. Methods for solving Fokker-Planck equations that evolve on Lie groups then become important. Such equations can be solved using the operational properties of group Fourier transforms in which irreducible unitary representation (IUR) matrices play a critical role. Therefore, we develop a simple approach for the numerical approximation of all the IUR matrices for two of the groups of most interest in robotics: the rotation group in three-dimensional space, SO(3), and the Euclidean motion group of the plane, SE(2). This approach uses the exponential mapping from the Lie algebras of these groups, and takes advantage of the sparse nature of the Lie algebra representation matrices. Other techniques for density estimation on groups are also explored. The computed densities are applied in the context of probabilistic path planning for kinematic cart in the plane and flexible needle steering in three-dimensional space. In these examples the injection of artificial noise into the computational models (rather than noise in the actual physical systems) serves as a tool to search the configuration spaces and plan paths. Finally, we illustrate how density estimation problems arise in the characterization of physical noise in orientational sensors such as gyroscopes. PMID:20454468

Practical aspects and uncertainty analysis of biological effective dose (BED) regarding its three-dimensional calculation in multiphase radiotherapy treatment plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kauweloa, Kevin I., E-mail: Kauweloa@livemail.uthscsa.edu; Gutierrez, Alonso N.; Bergamo, Angelo

2014-07-15

Purpose: There is a growing interest in the radiation oncology community to use the biological effective dose (BED) rather than the physical dose (PD) in treatment plan evaluation and optimization due to its stronger correlation with radiobiological effects. Radiotherapy patients may receive treatments involving a single only phase or multiple phases (e.g., primary and boost). Since most treatment planning systems cannot calculate the analytical BED distribution in multiphase treatments, an approximate multiphase BED expression, which is based on the total physical dose distribution, has been used. The purpose of this paper is to reveal the mathematical properties of the approximatemore » BED formulation, relative to the true BED. Methods: The mathematical properties of the approximate multiphase BED equation are analyzed and evaluated. In order to better understand the accuracy of the approximate multiphase BED equation, the true multiphase BED equation was derived and the mathematical differences between the true and approximate multiphase BED equations were determined. The magnitude of its inaccuracies under common clinical circumstances was also studied. All calculations were performed on a voxel-by-voxel basis using the three-dimensional dose matrices. Results: Results showed that the approximate multiphase BED equation is accurate only when the dose-per-fractions (DPFs) in both the first and second phases are equal, which occur when the dose distribution does not significantly change between the phases. In the case of heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the inaccuracy of the approximate multiphase BED is greater. These characteristics are usually seen in the dose distributions being delivered to organs at risk rather than to targets. Conclusions: The finding of this study indicates that the true multiphase BED equation should be implemented in the treatment planning systems due to the inconsistent accuracy of the approximate multiphase BED equation in most of the clinical situations.« less

Form and function of the human and chimpanzee forefoot: implications for early hominin bipedalism

PubMed Central

Fernández, Peter J.; Holowka, Nicholas B.; Demes, Brigitte; Jungers, William L.

2016-01-01

During bipedal walking, modern humans dorsiflex their forefoot at the metatarsophalangeal joints (MTPJs) prior to push off, which tightens the plantar soft tissues to convert the foot into a stiff propulsive lever. Particular features of metatarsal head morphology such as “dorsal doming” are thought to facilitate this stiffening mechanism. In contrast, chimpanzees are believed to possess MTPJ morphology that precludes high dorsiflexion excursions during terrestrial locomotion. The morphological affinity of the metatarsal heads has been used to reconstruct locomotor behavior in fossil hominins, but few studies have provided detailed empirical data to validate the assumed link between morphology and function at the MTPJs. Using three-dimensional kinematic and morphometric analyses, we show that humans push off with greater peak dorsiflexion angles at all MTPJs than do chimpanzees during bipedal and quadrupedal walking, with the greatest disparity occurring at MTPJ 1. Among MTPJs 2–5, both species exhibit decreasing peak angles from medial to lateral. This kinematic pattern is mirrored in the morphometric analyses of metatarsal head shape. Analyses of Australopithecus afarensis metatarsals reveal morphology intermediate between humans and chimpanzees, suggesting that this species used different bipedal push-off kinematics than modern humans, perhaps resulting in a less efficient form of bipedalism. PMID:27464580

IMS/Satellite Situation Center report: Orbit plots and bar charts for Prognoz 4, days 1-91 1976

NASA Technical Reports Server (NTRS)

1976-01-01

Orbit plots for the Prognoz 4 satellite for the time period January to March 1976 are given. This satellite was identified as a possible important contributor to the International Magnetospheric Study project. The orbits were based on an element epoch of December 26, 1975, 3h 8min and 17s. In view of the low perigee of this satellite, the Satellite Situation Center (SSC) considered that the effect of atmospheric drag precludes orbit predictions for the length of time normally used by the SSC for high-altitude satellites. Consequently, orbit data are shown for the first 3 months of 1976 only. The orbit generated for this report was based on the earlier epoch, and it positions the satellite within 30s of the ascending node at the later epoch. Therefore, within the accuracy of the plots shown in this report, the orbit used was regarded as an achieved orbit. The orbit information is displayed graphically in four ways: bar charts, geocentric solar ecliptic plots, boundary plots, and solar magnetic latitude versus local time plots. The most concise presentation is the bar charts. The bar charts give the crude three-dimensional position of the satellite for each magnetospheric region.

Natural Inhibitors of Snake Venom Metalloendopeptidases: History and Current Challenges

PubMed Central

Bastos, Viviane A.; Gomes-Neto, Francisco; Perales, Jonas; Neves-Ferreira, Ana Gisele C.; Valente, Richard H.

2016-01-01

The research on natural snake venom metalloendopeptidase inhibitors (SVMPIs) began in the 18th century with the pioneering work of Fontana on the resistance that vipers exhibited to their own venom. During the past 40 years, SVMPIs have been isolated mainly from the sera of resistant animals, and characterized to different extents. They are acidic oligomeric glycoproteins that remain biologically active over a wide range of pH and temperature values. Based on primary structure determination, mammalian plasmatic SVMPIs are classified as members of the immunoglobulin (Ig) supergene protein family, while the one isolated from muscle belongs to the ficolin/opsonin P35 family. On the other hand, SVMPIs from snake plasma have been placed in the cystatin superfamily. These natural antitoxins constitute the first line of defense against snake venoms, inhibiting the catalytic activities of snake venom metalloendopeptidases through the establishment of high-affinity, non-covalent interactions. This review presents a historical account of the field of natural resistance, summarizing its main discoveries and current challenges, which are mostly related to the limitations that preclude three-dimensional structural determinations of these inhibitors using “gold-standard” methods; perspectives on how to circumvent such limitations are presented. Potential applications of these SVMPIs in medicine are also highlighted. PMID:27571103

Conventional plate fixation method versus pre-operative virtual simulation and three-dimensional printing-assisted contoured plate fixation method in the treatment of anterior pelvic ring fracture.

PubMed

Hung, Chun-Chi; Li, Yuan-Ta; Chou, Yu-Ching; Chen, Jia-En; Wu, Chia-Chun; Shen, Hsain-Chung; Yeh, Tsu-Te

2018-05-03

Treating pelvic fractures remains a challenging task for orthopaedic surgeons. We aimed to evaluate the feasibility, accuracy, and effectiveness of three-dimensional (3D) printing technology and computer-assisted virtual surgery for pre-operative planning in anterior ring fractures of the pelvis. We hypothesized that using 3D printing models would reduce operation time and significantly improve the surgical outcomes of pelvic fracture repair. We retrospectively reviewed the records of 30 patients with pelvic fractures treated by anterior pelvic fixation with locking plates (14 patients, conventional locking plate fixation; 16 patients, pre-operative virtual simulation with 3D, printing-assisted, pre-contoured, locking plate fixation). We compared operative time, instrumentation time, blood loss, and post-surgical residual displacements, as evaluated on X-ray films, among groups. Statistical analyses evaluated significant differences between the groups for each of these variables. The patients treated with the virtual simulation and 3D printing-assisted technique had significantly shorter internal fixation times, shorter surgery duration, and less blood loss (- 57 minutes, - 70 minutes, and - 274 ml, respectively; P < 0.05) than patients in the conventional surgery group. However, the post-operative radiological result was similar between groups (P > 0.05). The complication rate was less in the 3D printing group (1/16 patients) than in the conventional surgery group (3/14 patients). The 3D simulation and printing technique is an effective and reliable method for treating anterior pelvic ring fractures. With precise pre-operative planning and accurate execution of the procedures, this time-saving approach can provide a more personalized treatment plan, allowing for a safer orthopaedic surgery.

Effectiveness of Educational Intervention on the Congruence of Prostate and Rectal Contouring as Compared With a Gold Standard in Three-Dimensional Radiotherapy for Prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szumacher, Ewa, E-mail: Ewa.Szumacher@sunnybrook.c; Harnett, Nicole; Warner, Saar

Purpose: To examine effects of a teaching intervention on precise delineation of the prostate and rectum during planning of three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Methods and Materials: A pretest, posttest, randomized controlled group design was used. During pretest all participants contoured prostate and rectum on planning CT. Afterward, they participated in two types of workshops. The experimental group engaged in an interactive teaching session focused on prostate and rectum MR anatomy compared with CT anatomy. The control group focused on 3D-CRT planning without mention of prostate or rectal contouring. The experimental group practiced on fused MR-CT images, whereasmore » the control group practiced on CT images. All participants completed the posttest. Results: Thirty-one trainees (12 male, 19 female) were randomly assigned to two groups, 17 in the experimental arm, and 14 in the control group. Seventeen felt familiar or very familiar with pelvic organ contouring, 12 somewhat, and 2 had never done it. Thirteen felt confident with organ contouring, 13 somewhat, and 5 not confident. The demographics and composition of groups were analyzed with chi{sup 2} and repeated-measures analysis of variance with the two groups (experimental or control) and two tests (pre- or posttest) as factors. Satisfaction with the course and long-term effects of the course on practice were assessed with immediate and delayed surveys. All performance variables showed a similar pattern of results. Conclusions: The training sessions improved the technical performance similarly in both groups. Participants were satisfied with the course content, and the delayed survey reflected that cognitively participants felt more confident with prostate and rectum contouring and would investigate opportunities to learn more about organ contouring.« less

Surgeon-Based 3D Printing for Microvascular Bone Flaps.

PubMed

Taylor, Erin M; Iorio, Matthew L

2017-07-01

Background  Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods  Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results  Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions  Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence  Level IV. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Burden of Stigma on Health and Well-Being: A Taxonomy of Concealment, Course, Disruptiveness, Aesthetics, Origin, and Peril Across 93 Stigmas.

PubMed

Pachankis, John E; Hatzenbuehler, Mark L; Wang, Katie; Burton, Charles L; Crawford, Forrest W; Phelan, Jo C; Link, Bruce G

2018-04-01

Most individuals are stigmatized at some point. However, research often examines stigmas separately, thus underestimating the overall impact of stigma and precluding comparisons across stigmatized identities and conditions. In their classic text, Social Stigma: The Psychology of Marked Relationships, Edward Jones and colleagues laid the groundwork for unifying the study of different stigmas by considering the shared dimensional features of stigmas: aesthetics, concealability, course, disruptiveness, origin, peril. Despite the prominence of this framework, no study has documented the extent to which stigmas differ along these dimensions, and the implications of this variation for health and well-being. We reinvigorated this framework to spur a comprehensive account of stigma's impact by classifying 93 stigmas along these dimensions. With the input of expert and general public raters, we then located these stigmas in a six-dimensional space and created discrete clusters organized around these dimensions. Next, we linked this taxonomy to health and stigma-related mechanisms. This quantitative taxonomy offers parsimonious insights into the relationship among the numerous qualities of numerous stigmas and health.

Low Dimensional Temporal Organization of Spontaneous Eye Blinks in Adults with Developmental Disabilities and Stereotyped Movement Disorder

PubMed Central

Lee, Mei-Hua; Bodfish, James W.; Lewis, Mark H.; Newell, Karl M.

2009-01-01

This study investigated the mean rate and time-dependent sequential organization of spontaneous eye blinks in adults with intellectual and developmental disability (IDD) and individuals from this group that were additionally categorized with stereotypic movement disorder (IDD+SMD). The mean blink rate was lower in the IDD+SMD group than the IDD group and both of these groups had a lower blink rate than a contrast group of healthy adults. In the IDD group the n to n+1 sequential organization over time of the eye blink durations showed a stronger compensatory organization than the contrast group suggesting decreased complexity/dimensionality of eye-blink behavior. Very low blink rate (and thus insufficient time series data) precluded analysis of time-dependent sequential properties in the IDD+SMD group. These findings support the hypothesis that both IDD and SMD are associated with a reduction in the dimension and adaptability of movement behavior and that this may serve as a risk factor for the expression of abnormal movements. PMID:19819672

Low-cost Method for Obtaining Medical Rapid Prototyping Using Desktop 3D printing: A Novel Technique for Mandibular Reconstruction Planning.

PubMed

Velasco, Ignacio; Vahdani, Soheil; Ramos, Hector

2017-09-01

Three-dimensional (3D) printing is relatively a new technology with clinical applications, which enable us to create rapid accurate prototype of the selected anatomic region, making it possible to plan complex surgery and pre-bend hardware for individual surgical cases. This study aimed to express our experience with the use of medical rapid prototype (MRP) of the maxillofacial region created by desktop 3D printer and its application in maxillofacial reconstructive surgeries. Three patients with benign mandible tumors were included in this study after obtaining informed consent. All patient's maxillofacial CT scan data was processed by segmentation and isolation software and mandible MRP was printed using our desktop 3D printer. These models were used for preoperative surgical planning and prebending of the reconstruction plate. MRP created by desktop 3D printer is a cost-efficient, quick and easily produced appliance for the planning of reconstructive surgery. It can contribute in patient orientation and helping them in a better understanding of their condition and proposed surgical treatment. It helps surgeons for pre-operative planning in the resection or reconstruction cases and represent an excellent tool in academic setting for residents training. The pre-bended reconstruction plate based on MRP, resulted in decreased surgery time, cost and anesthesia risks on the patients. Key words: 3D printing, medical modeling, rapid prototype, mandibular reconstruction, ameloblastoma.

3D printing from cardiovascular CT: a practical guide and review

PubMed Central

Birbara, Nicolette S.; Hussain, Tarique; Greil, Gerald; Foley, Thomas A.; Pather, Nalini

2017-01-01

Current cardiovascular imaging techniques allow anatomical relationships and pathological conditions to be captured in three dimensions. Three-dimensional (3D) printing, or rapid prototyping, has also become readily available and made it possible to transform virtual reconstructions into physical 3D models. This technology has been utilised to demonstrate cardiovascular anatomy and disease in clinical, research and educational settings. In particular, 3D models have been generated from cardiovascular computed tomography (CT) imaging data for purposes such as surgical planning and teaching. This review summarises applications, limitations and practical steps required to create a 3D printed model from cardiovascular CT. PMID:29255693

Efficient implementation of parallel three-dimensional FFT on clusters of PCs

NASA Astrophysics Data System (ADS)

Takahashi, Daisuke

2003-05-01

In this paper, we propose a high-performance parallel three-dimensional fast Fourier transform (FFT) algorithm on clusters of PCs. The three-dimensional FFT algorithm can be altered into a block three-dimensional FFT algorithm to reduce the number of cache misses. We show that the block three-dimensional FFT algorithm improves performance by utilizing the cache memory effectively. We use the block three-dimensional FFT algorithm to implement the parallel three-dimensional FFT algorithm. We succeeded in obtaining performance of over 1.3 GFLOPS on an 8-node dual Pentium III 1 GHz PC SMP cluster.

Three-dimensional turbulent boundary layers; Proceedings of the Symposium, Berlin, West Germany, March 29-April 1, 1982

NASA Astrophysics Data System (ADS)

Fernholz, H. H.; Krause, E.

Papers are presented on recent research concerning three-dimensional turbulent boundary layers. Topics examined include experimental techniques in three-dimensional turbulent boundary layers, turbulence measurements in ship-model flow, measurements of Reynolds-stress profiles in the stern region of a ship model, the effects of crossflow on the vortex-layer-type three-dimensional flow separation, and wind tunnel investigations of some three-dimensional separated turbulent boundary layers. Also examined are three-dimensional boundary layers in turbomachines, the boundary layers on bodies of revolution spinning in axial flows, the effect on a developed turbulent boundary layer of a sudden local wall motion, three-dimensional turbulent boundary layer along a concave wall, the numerical computation of three-dimensional boundary layers, a numerical study of corner flows, three-dimensional boundary calculations in design aerodynamics, and turbulent boundary-layer calculations in design aerodynamics. For individual items see A83-47012 to A83-47036

[Description of latest generation equipment in external radiotherapy].

PubMed

Pellejero, S; Lozares, S; Mañeru, F

2009-01-01

Both the planning systems and the form of administering radiotherapy have changed radically since the introduction of 3D planning. At present treatment planning based on computerised axial tomography (CAT) images is standard practice in radiotherapy services. In recent years lineal accelerators for medical use have incorporated technology capable of administering intensity modulated radiation beams (IMRT). With this mode distributions of conformed doses are generated that adjust to the three dimensional form of the white volume, providing appropriate coverage and a lower dose to nearby risk organs. The use of IMRT is rapidly spreading amongst radiotherapy centres throughout the world. This growing use of IMRT has focused attention on the need for greater control of the geometric uncertainties in positioning the patient and control of internal movements. To this end, both flat and volumetric image systems have been incorporated into the treatment equipment, making image-guided radiotherapy (IGRT) possible. This article offers a brief description of the latest advances included in the planning and administration of radiotherapy treatment.

Development of 3-D Ice Accretion Measurement Method

NASA Technical Reports Server (NTRS)

Lee, Sam; Broeren, Andy P.; Addy, Harold E., Jr.; Sills, Robert; Pifer, Ellen M.

2012-01-01

A research plan is currently being implemented by NASA to develop and validate the use of a commercial laser scanner to record and archive fully three-dimensional (3-D) ice shapes from an icing wind tunnel. The plan focused specifically upon measuring ice accreted in the NASA Icing Research Tunnel (IRT). The plan was divided into two phases. The first phase was the identification and selection of the laser scanning system and the post-processing software to purchase and develop further. The second phase was the implementation and validation of the selected system through a series of icing and aerodynamic tests. Phase I of the research plan has been completed. It consisted of evaluating several scanning hardware and software systems against an established selection criteria through demonstrations in the IRT. The results of Phase I showed that all of the scanning systems that were evaluated were equally capable of scanning ice shapes. The factors that differentiated the scanners were ease of use and the ability to operate in a wide range of IRT environmental conditions.

Educational utility of advanced three-dimensional virtual imaging in evaluating the anatomical configuration of the frontal recess.

PubMed

Agbetoba, Abib; Luong, Amber; Siow, Jin Keat; Senior, Brent; Callejas, Claudio; Szczygielski, Kornel; Citardi, Martin J

2017-02-01

Endoscopic sinus surgery represents a cornerstone in the professional development of otorhinolaryngology trainees. Mastery of these surgical skills requires an understanding of paranasal sinus and skull-base anatomy. The frontal sinus is associated with a wide range of variation and complex anatomical configuration, and thus represents an important challenge for all trainees performing endoscopic sinus surgery. Forty-five otorhinolaryngology trainees and 20 medical school students from 5 academic institutions were enrolled and randomized into 1 of 2 groups. Each subject underwent learning of frontal recess anatomy with both traditional 2-dimensional (2D) learning methods using a standard Digital Imaging and Communications in Medicine (DICOM) viewing software (RadiAnt Dicom Viewer Version 1.9.16) and 3-dimensional (3D) learning utilizing a novel preoperative virtual planning software (Scopis Building Blocks), with one half learning with the 2D method first and the other half learning with the 3D method first. Four questionnaires that included a total of 20 items were scored for subjects' self-assessment on knowledge of frontal recess and frontal sinus drainage pathway anatomy following each learned modality. A 2-sample Wilcoxon rank-sum test was used in the statistical analysis comparing the 2 groups. Most trainees (89%) believed that the virtual 3D planning software significantly improved their understanding of the spatial orientation of the frontal sinus drainage pathway. Incorporation of virtual 3D planning surgical software may help augment trainees' understanding and spatial orientation of the frontal recess and sinus anatomy. The potential increase in trainee proficiency and comprehension theoretically may translate to improved surgical skill and patient outcomes and in reduced surgical time. © 2016 ARS-AAOA, LLC.

Three-dimensional imaging and remote sensing imaging; Proceedings of the Meeting, Los Angeles, CA, Jan. 14, 15, 1988

NASA Astrophysics Data System (ADS)

Robbins, Woodrow E.

1988-01-01

The present conference discusses topics in novel technologies and techniques of three-dimensional imaging, human factors-related issues in three-dimensional display system design, three-dimensional imaging applications, and image processing for remote sensing. Attention is given to a 19-inch parallactiscope, a chromostereoscopic CRT-based display, the 'SpaceGraph' true three-dimensional peripheral, advantages of three-dimensional displays, holographic stereograms generated with a liquid crystal spatial light modulator, algorithms and display techniques for four-dimensional Cartesian graphics, an image processing system for automatic retina diagnosis, the automatic frequency control of a pulsed CO2 laser, and a three-dimensional display of magnetic resonance imaging of the spine.

Virtual reality system for planning minimally invasive neurosurgery. Technical note.

PubMed

Stadie, Axel Thomas; Kockro, Ralf Alfons; Reisch, Robert; Tropine, Andrei; Boor, Stephan; Stoeter, Peter; Perneczky, Axel

2008-02-01

The authors report on their experience with a 3D virtual reality system for planning minimally invasive neurosurgical procedures. Between October 2002 and April 2006, the authors used the Dextroscope (Volume Interactions, Ltd.) to plan neurosurgical procedures in 106 patients, including 100 with intracranial and 6 with spinal lesions. The planning was performed 1 to 3 days preoperatively, and in 12 cases, 3D prints of the planning procedure were taken into the operating room. A questionnaire was completed by the neurosurgeon after the planning procedure. After a short period of acclimatization, the system proved easy to operate and is currently used routinely for preoperative planning of difficult cases at the authors' institution. It was felt that working with a virtual reality multimodal model of the patient significantly improved surgical planning. The pathoanatomy in individual patients could easily be understood in great detail, enabling the authors to determine the surgical trajectory precisely and in the most minimally invasive way. The authors found the preoperative 3D model to be in high concordance with intraoperative conditions; the resulting intraoperative "déjà-vu" feeling enhanced surgical confidence. In all procedures planned with the Dextroscope, the chosen surgical strategy proved to be the correct choice. Three-dimensional virtual reality models of a patient allow quick and easy understanding of complex intracranial lesions.

Development of a patient-specific 3D dose evaluation program for QA in radiation therapy

NASA Astrophysics Data System (ADS)

Lee, Suk; Chang, Kyung Hwan; Cao, Yuan Jie; Shim, Jang Bo; Yang, Dae Sik; Park, Young Je; Yoon, Won Sup; Kim, Chul Yong

2015-03-01

We present preliminary results for a 3-dimensional dose evaluation software system ( P DRESS, patient-specific 3-dimensional dose real evaluation system). Scanned computed tomography (CT) images obtained by using dosimetry were transferred to the radiation treatment planning system (ECLIPSE, VARIAN, Palo Alto, CA) where the intensity modulated radiation therapy (IMRT) nasopharynx plan was designed. We used a 10 MV photon beam (CLiX, VARIAN, Palo Alto, CA) to deliver the nasopharynx treatment plan. After irradiation, the TENOMAG dosimeter was scanned using a VISTA ™ scanner. The scanned data were reconstructed using VistaRecon software to obtain a 3D dose distribution of the optical density. An optical-CT scanner was used to readout the dose distribution in the gel dosimeter. Moreover, we developed the P DRESS by using Flatform, which were developed by our group, to display the 3D dose distribution by loading the DICOM RT data which are exported from the radiotherapy treatment plan (RTP) and the optical-CT reconstructed VFF file, into the independent P DRESS with an ioniz ation chamber and EBT film was used to compare the dose distribution calculated from the RTP with that measured by using a gel dosimeter. The agreement between the normalized EBT, the gel dosimeter and RTP data was evaluated using both qualitative and quantitative methods, such as the isodose distribution, dose difference, point value, and profile. The profiles showed good agreement between the RTP data and the gel dosimeter data, and the precision of the dose distribution was within ±3%. The results from this study showed significantly discrepancies between the dose distribution calculated from the treatment plan and the dose distribution measured by a TENOMAG gel and by scanning with an optical CT scanner. The 3D dose evaluation software system ( P DRESS, patient specific dose real evaluation system), which were developed in this study evaluates the accuracies of the three-dimensional dose distributions. Further applications of the system utility are expected to result from future studies.

Three-dimensional separation for interaction of shock waves with turbulent boundary layers

NASA Technical Reports Server (NTRS)

Goldberg, T. J.

1973-01-01

For the interaction of shock waves with turbulent boundary layers, obtained experimental three-dimensional separation results and correlations with earlier two-dimensional and three-dimensional data are presented. It is shown that separation occurs much earlier for turbulent three-dimensional than for two-dimensional flow at hypersonic speeds.

MR angiography fusion technique for treatment planning of intracranial arteriovenous malformations.

PubMed

McGee, Kiaran P; Ivanovic, Vladimir; Felmlee, Joel P; Meyer, Fredrick B; Pollock, Bruce E; Huston, John

2006-03-01

To develop an image fusion technique using elliptical centric contrast-enhanced (CE) MR angiography (MRA) and three-dimensional (3D) time-of-flight (TOF) acquisitions for radiosurgery treatment planning of arteriovenous malformations (AVMs). CE and 3D-TOF MR angiograms with disparate in-plane fields of view (FOVs) were acquired, followed by k-space reformatting to provide equal voxel dimensions. Spatial domain addition was performed to provide a third, fused data volume. Spatial distortion was evaluated on an MRA phantom and provided slice-dependent and global distortion along the three physical dimensions of the MR scanner. In vivo validation was performed on 10 patients with intracranial AVMs prior to their conventional angiogram on the day of gamma knife radiosurgery. Spatial distortion in the phantom within a volume of 14 x 14 x 3.2 cm(3) was less than +/-1 mm (+/-1 standard deviation (SD)) for CE and 3D-TOF data sets. Fused data volumes were successfully generated for all 10 patients. Image fusion can be used to obtain high-resolution CE-MRA images of intracranial AVMs while keeping the fiducial markers needed for gamma knife radiosurgery planning. The spatial fidelity of these data is within the tolerance acceptable for daily quality control (QC) purposes and gamma knife treatment planning. (c) 2006 Wiley-Liss, Inc.

Virtual skeletal complex model- and landmark-guided orthognathic surgery system.

PubMed

Lee, Sang-Jeong; Woo, Sang-Yoon; Huh, Kyung-Hoe; Lee, Sam-Sun; Heo, Min-Suk; Choi, Soon-Chul; Han, Jeong Joon; Yang, Hoon Joo; Hwang, Soon Jung; Yi, Won-Jin

2016-05-01

In this study, correction of the maxillofacial deformities was performed by repositioning bone segments to an appropriate location according to the preoperative planning in orthognathic surgery. The surgery was planned using the patient's virtual skeletal models fused with optically scanned three-dimensional dentition. The virtual maxillomandibular complex (MMC) model of the patient's final occlusal relationship was generated by fusion of the maxillary and mandibular models with scanned occlusion. The final position of the MMC was simulated preoperatively by planning and was used as a goal model for guidance. During surgery, the intraoperative registration was finished immediately using only software processing. For accurate repositioning, the intraoperative MMC model was visualized on the monitor with respect to the simulated MMC model, and the intraoperative positions of multiple landmarks were also visualized on the MMC surface model. The deviation errors between the intraoperative and the final positions of each landmark were visualized quantitatively. As a result, the surgeon could easily recognize the three-dimensional deviation of the intraoperative MMC state from the final goal model without manually applying a pointing tool, and could also quickly determine the amount and direction of further MMC movements needed to reach the goal position. The surgeon could also perform various osteotomies and remove bone interference conveniently, as the maxillary tracking tool could be separated from the MMC. The root mean square (RMS) difference between the preoperative planning and the intraoperative guidance was 1.16 ± 0.34 mm immediately after repositioning. After surgery, the RMS differences between the planning and the postoperative computed tomographic model were 1.31 ± 0.28 mm and 1.74 ± 0.73 mm for the maxillary and mandibular landmarks, respectively. Our method provides accurate and flexible guidance for bimaxillary orthognathic surgery based on intraoperative visualization and quantification of deviations for simulated postoperative MMC and landmarks. The guidance using simulated skeletal models and landmarks can complement and improve conventional navigational surgery for bone repositioning in the craniomaxillofacial area. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

TU-H-CAMPUS-JeP2-03: Machine-Learning-Based Delineation Framework of GTV Regions of Solid and Ground Glass Opacity Lung Tumors at Datasets of Planning CT and PET/CT Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikushima, K; Arimura, H; Jin, Z

Purpose: In radiation treatment planning, delineation of gross tumor volume (GTV) is very important, because the GTVs affect the accuracies of radiation therapy procedure. To assist radiation oncologists in the delineation of GTV regions while treatment planning for lung cancer, we have proposed a machine-learning-based delineation framework of GTV regions of solid and ground glass opacity (GGO) lung tumors following by optimum contour selection (OCS) method. Methods: Our basic idea was to feed voxel-based image features around GTV contours determined by radiation oncologists into a machine learning classifier in the training step, after which the classifier produced the degree ofmore » GTV for each voxel in the testing step. Ten data sets of planning CT and PET/CT images were selected for this study. The support vector machine (SVM), which learned voxel-based features which include voxel value and magnitudes of image gradient vector that obtained from each voxel in the planning CT and PET/CT images, extracted initial GTV regions. The final GTV regions were determined using the OCS method that was able to select a global optimum object contour based on multiple active delineations with a level set method around the GTV. To evaluate the results of proposed framework for ten cases (solid:6, GGO:4), we used the three-dimensional Dice similarity coefficient (DSC), which denoted the degree of region similarity between the GTVs delineated by radiation oncologists and the proposed framework. Results: The proposed method achieved an average three-dimensional DSC of 0.81 for ten lung cancer patients, while a standardized uptake value-based method segmented GTV regions with the DSC of 0.43. The average DSCs for solid and GGO were 0.84 and 0.76, respectively, obtained by the proposed framework. Conclusion: The proposed framework with the support vector machine may be useful for assisting radiation oncologists in delineating solid and GGO lung tumors.« less