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Zeitschriftenartikel zum Thema "CBCT technology"
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Jonczyk, M., F. Collettini, D. Geisel, D. Schnapauff, G. Böning, G. Wieners und G. Gebauer. „Radiation exposure during TACE procedures using additional cone-beam CT (CBCT) for guidance: safety and precautions“. Acta Radiologica 59, Nr. 11 (28.02.2018): 1277–84. http://dx.doi.org/10.1177/0284185118761203.
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Background During transarterial chemoembolization (TACE), cone-beam computed tomography (CBCT) can be used for tumor and feeding vessel detection as well as postembolization CT imaging. However, there will be additional radiation exposure from CBCT. Purpose To evaluate the additional dose raised through CBCT-assisted guidance in comparison to TACE procedures guided with pulsed digital subtraction angiography (DSA) alone. Material and Methods In 70 of 140 consecutive patients undergoing TACE for liver cancer, CBCT was used to facilitate the TACE. Cumulative dose area product (DAP), cumulative kerma(air), DAP values of DSA, total and cine specific fluoroscopy times (FT) of 1375 DSA runs, and DAP of 91 CBCTs were recorded and analyzed using Spearman's correlation, Mann–Whitney U-test, and Kruskal–Wallis test. P values < 0.05 were considered significant. Results Additional CBCT increased DAP by 2% ( P = 0.737), kerma(air) by 24.6% ( P = 0.206), and FT by 0.02% ( P = 0.453). Subgroup analysis revealed that postembolization CBCT for detection of ethiodized oil deposits added more DAP to the procedure. Performing CBCT-assisted TACE, DSA until first CBCT contributed about 38% to the total DAP. Guidance CBCT acquisitions conduced to 6% of the procedure's DAP. Additional DSA for guidance after CBCT acquisition required approximately 46% of the mean DAP. The last DSA run for documentation purposes contributed about 10% of the DAP. Conclusion CBCT adds radiation exposure in TACE. However, the capability of CBCT to detect vessels and overlay in real-time during fluoroscopy facilitates TACE with resultant reduction of DAPs up to 46%.
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Franks, K. N., A. Bezjak, J. Higgins, W. Li, T. G. Purdie, A. Brade, J. Cho, D. Payne, D. A. Jaffray und J. Bissonnette. „Image-guided lung radiotherapy: Bringing technology into routine clinical practice“. Journal of Clinical Oncology 25, Nr. 18_suppl (20.06.2007): 18093. http://dx.doi.org/10.1200/jco.2007.25.18_suppl.18093.
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18093 Background: Cone-beam CT (CBCT), an imaging system integrated into the RT treatment unit, produces 3D images far superior to the conventional 2D portal images used for verification of patient (pt) set-up. This allows direct matching to the RT treatment planning CT images, potentially increasing the precision of RT delivery. We report on the broad implementation of this new RT image-guided paradigm in lung cancer patients at our center. Methods: All lung cancer pts undergoing radical RT were planned using 4DCT and imaged daily for repositioning with CBCT since 04/06. Initially, CBCT datasets were compared with the planning CT to assess the setup error (bone surrogate), using two immobilisation methods: evacuated bags (EB) and chest-board (ChB). Discrepancies >3 mm between the two datasets, in any direction, were corrected before the start of each RT fraction. Data were retrospectively analyzed to assess the initial and residual discrepancies (43 pts; 1,128 CBCTs).Alternative matching strategies were also tested (carina & tumor) using both manual and automatic methods (30 pts). Protocols had REB approval. Results: In total, 657 (58%) RT treatments required adjustment after initial positioning on the treatment couch. The two immobilization methods were equivalent (p=0.18); the mean pt shift required for ChB pts was 55±18mm and for EB pts was 69±32mm. Given that residual uncertainties were <3 mm, margin calculations reveal that large reductions (54–79%) may be possible for tumors not influenced by respiratory motion. The performance of automatic matching was reasonable for carina (correlation [r] 0.8–0.84) and bone (r 0.58–0.81) but discrepancies were seen for tumor (r 0.63–0.69). Conclusions: Daily CBCT provides greatly increased accuracy of set-up, to within 3 mm of the planned bony anatomy, which may improve tumor control by confirming geographic accuracy. The role of image-guided RT in reducing the volume of irradiated normal tissue may play an important role in addressing toxicity concerns associated with combined modality treatment and facilitate safe RT dose escalation. In addition to increasing RT precision, daily CBCT allows routine visualisation of the tumor as well as to bony anatomy, presenting an exciting opportunity to adapt the treatment plan based on an individual response. [Table: see text]
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Monserrate, Andrés, Benjamin Zussman, Alp Ozpinar, Ajay Niranjan, John C. Flickinger und Peter C. Gerszten. „Stereotactic radiosurgery for intradural spine tumors using cone-beam CT image guidance“. Neurosurgical Focus 42, Nr. 1 (Januar 2017): E11. http://dx.doi.org/10.3171/2016.9.focus16356.
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OBJECTIVE Cone-beam CT (CBCT) image guidance technology has been widely adopted for spine radiosurgery delivery. There is relatively little experience with spine radiosurgery for intradural tumors using CBCT image guidance. This study prospectively evaluated a series of intradural spine tumors treated with radiosurgery. Patient setup accuracy for spine radiosurgery delivery using CBCT image guidance for intradural spine tumors was determined. METHODS Eighty-two patients with intradural tumors were treated and prospectively evaluated. The positioning deviations of the spine radiosurgery treatments in patients were recorded. Radiosurgery was delivered using a linear accelerator with a beam modulator and CBCT image guidance combined with a robotic couch that allows positioning correction in 3 translational and 3 rotational directions. To measure patient movement, 3 quality assurance CBCTs were performed and recorded in 30 patients: before, halfway, and after the radiosurgery treatment. The positioning data and fused images of planning CT and CBCT from the treatments were analyzed to determine intrafraction patient movements. From each of 3 CBCTs, 3 translational and 3 rotational coordinates were obtained. RESULTS The radiosurgery procedure was successfully completed for all patients. Lesion locations included cervical (22), thoracic (17), lumbar (38), and sacral (5). Tumor histologies included schwannoma (27), neurofibromas (18), meningioma (16), hemangioblastoma (8), and ependymoma (5). The mean prescription dose was 17 Gy (range 12–27 Gy) delivered in 1–3 fractions. At the halfway point of the radiation, the translational variations and standard deviations were 0.4 ± 0.5, 0.5 ± 0.8, and 0.4 ± 0.5 mm in the lateral (x), longitudinal (y), and anteroposterior (z) directions, respectively. Similarly, the variations immediately after treatment were 0.5 ± 0.4, 0.5 ± 0.6, and 0.6 ± 0.5 mm along x, y, and z directions, respectively. The mean rotational angles were 0.3° ± 0.4°, 0.3° ± 0.4°, and 0.3° ± 0.4° along yaw, roll, and pitch, respectively, at the halfway point and 0.5° ± 0.5°, 0.4° ± 0.5°, and 0.2° ± 0.3° immediately after treatment. CONCLUSIONS Radiosurgery offers an alternative treatment option for intradural spine tumors in patients who may not be optimal candidates for open surgery. CBCT image guidance for patient setup for spine radiosurgery is accurate and successful in patients with intradural tumors.
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Gerszten, Peter C., Josef Novotny, Mubina Quader, Valerie C. Dewald und John C. Flickinger. „Prospective evaluation of a dedicated spine radiosurgery program using the Elekta Synergy S system“. Journal of Neurosurgery 113, Special_Supplement (Dezember 2010): 236–41. http://dx.doi.org/10.3171/2010.8.gks10949.
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Object Cone beam CT (CBCT) image guidance has recently been adopted for the delivery of spine radiosurgery. In 2007, the authors' institution began a dedicated spine radiosurgery program using the Elekta Synergy S system, which incorporates CBCT technology. In this study, the authors prospectively evaluated the Synergy S platform as a dedicated spine radiosurgery delivery system, including an evaluation of the accuracy of patient positioning using this technology, as part of a quality assurance program. Methods One hundred sixty-six spine and paraspinal lesions were treated using the Elekta Synergy S 6-MV LINAC with a beam modulator and CBCT image guidance combined with a HexaPOD couch that allows correction of patient positioning in 3 translational and 3 rotational directions. Stratifying the lesion by location, there were 28 cervical, 69 thoracic, 48 lumbar, and 21 sacral lesions. The most common histological types for the metastatic lesions (136 cases total) were breast, lung, sarcomas, and renal cells. The most common benign tumors (30 cases total) included 10 schwannomas, 5 neurofibromas, and 5 meningiomas. Twenty-eight lesions (17%) were intradural. To measure intratreatment patient movement, 3 quality assurance CBCTs were performed and recorded at separate times: immediately before treatment started; at the first third of the procedure; and at the second third of the procedure. The positioning data and fused images of the planning CT and CBCT were analyzed to determine intrafraction patient movements. From each of 3 quality assurance CBCT images, 3 translational and 3 rotational coordinates were obtained. Results The prescribed dose to the gross tumor volume, delivered in a single fraction, ranged from 12 to 20 Gy (mean 16 Gy) in this cohort. This dose was delivered by between 7 and 14 coplanar intensity-modulated radiation therapy beams (mean 9 beams). The gross tumor volumes ranged from 1.2 to 491.7 cm3 (mean 39.2 cm3). Mean treatment time including setup was 64 minutes. At the first third of the treatment, the magnitude of the 3D translational vector (X, Y, Z) was 1.1 ± 0.7 mm. Similarly, the 3D translational vector at the second third of the treatment was 1.0 ± 0.6 mm. The means ± SDs of the rotational angles were 0.2° ± 0.4°, 0.4° ± 0.5°, and 0.3° ± 0.5° along yaw, roll, and pitch, respectively, at the first third of the treatment, and 0.2° ± 0.3°, 0.4° ± 0.5°, and 0.4° ± 0.5°, respectively, at the second third of the treatment. Conclusions Single-fraction spine radiosurgery performed using the Synergy S platform and incorporating CBCT image guidance was determined to be feasible, accurate, and safe. This technique provides an overall translational position accuracy of < 2.0 mm.
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Rothom, Ronnachat, und Patchanee Chuveera. „Differences in Healing of a Horizontal Root Fracture as Seen on Conventional Periapical Radiography and Cone-Beam Computed Tomography“. Case Reports in Dentistry 2017 (2017): 1–5. http://dx.doi.org/10.1155/2017/2728964.
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Different locations and healing patterns of horizontal root fractures bear different prognoses. Conventional periapical radiographs have been routinely used for the evaluation of the locations and healing of horizontal root fractures, with the limitation of presenting two-dimensional images. The three-dimensional imaging technology, cone-beam computed tomography (CBCT), has recently gained interest in dental traumatology, in particular for locating and diagnosing root fractures. However, the assessment of healing patterns of horizontal root fracture using CBCT compared to conventional radiographs has not been established. This case report describes the different healing patterns evaluated by two-dimensional radiographs and CBCT of a horizontally root-fractured maxillary right central incisor treated with mineral trioxide aggregate (MTA) with a two-year follow-up. The findings suggest that the healing patterns of horizontal root fractures seen on conventional radiographs and CBCT may be different.
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Nanjannawar, Lalita G., Jiwanasha Manish Agrawal, Manish Suresh Agrawal und Anita D. Parushetti. „CBCT in Orthodontics: The Wave of Future“. Journal of Contemporary Dental Practice 14, Nr. 1 (2013): 153–57. http://dx.doi.org/10.5005/jp-journals-10024-1291.
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ABSTRACT Cone beam computed tomography (CBCT) has probably been one of the most revolutionary innovations in the field of dentistry in the past decade and it provides a novel platform for orthodontic diagnosis and treatment planning. Current imaging techniques are essentially two-dimensional (2D) representations of threedimensional (3D) objects and suffer from several limitations. Hence, fulfillment of ideal imaging goals has been limited. Twodimensional radiographs are insufficient, especially in complex cases like impacted teeth, supernumerary teeth and orthognathic surgeries. CBCT images provide far more detailed information than conventional 2D radiographs and are user friendly. Soft tissues, skull, airway and the dentition can be observed and measured on CBCT images in a 1:1 ratio. Clinical significance CBCT provides an excellent tool for accurate diagnosis, more predictable treatment planning, more efficient patient management and education, improved treatment outcome and patient satisfaction. This article focuses on various applications of cone beam CT technology in orthodontics. How to cite this article Agrawal JM, Agrawal MS, Nanjannawar LG, Parushetti AD. CBCT in Orthodontics: The Wave of Future. J Contemp Dent Pract 2013;14(1):153-157.
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Minami, Yasunori, Takamichi Murakami, Masayuki Kitano, Toshiharu Sakurai, Naoshi Nishida und Masatoshi Kudo. „Cone-Beam CT Angiography for Hepatocellular Carcinoma: Current Status“. Digestive Diseases 33, Nr. 6 (2015): 759–64. http://dx.doi.org/10.1159/000439100.
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Cone-beam CT (CBCT) is generated during a rotational sweep of the C-arm around the patient, and can be a valuable imaging technique, providing in situ cross-sectional imaging. It is easy to evaluate the morphologic characteristics of hepatic arteries from multiple views with the use of various reconstruction techniques, such as maximum intensity projection (MIP) and volume rendering. CBCT angiography is capable of providing more information than the standard 2-dimensional angiography in visualizing hepatocellular carcinomas (HCCs) and targeting tumors though precise microcatheter placement in close proximity to HCCs. It can also be useful in evaluating treatment success at the time of the procedure. It is anticipated that CBCT could reduce radiation exposure, the overall procedure time and contrast material use because it allows immediate feedback for an efficient angiographic procedure. Therefore, CBCT angiography is an exciting technology with the potential to significantly impact the practice of interventional radiology. The purpose of this article is to provide a review of the principles, clinical applications and technique of CBCT angiography for HCC treatment.
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Schnapauff, Dirk, Andreas Maxeiner, Gero Wieners, Timm Denecke, Bernd Hamm, Bernhard Gebauer und Martin Jonczyk. „Semi-automatic prostatic artery detection using cone-beam CT during prostatic arterial embolization“. Acta Radiologica 61, Nr. 8 (12.12.2019): 1116–24. http://dx.doi.org/10.1177/0284185119891689.
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Background Due to the broad variability of the prostatic artery (PA), its origin, small calibers, and tortuous courses, prostatic arterial embolization (PAE) is challenging, time-consuming, and results in high radiation doses. Purpose To evaluate the accuracy of PA detection using cone-beam computed tomography (CBCT) performed from the aortic bifurcation in combination with a semi-automatic detection software in comparison to oblique view digital subtraction angiography (DSA) with internal iliac artery (IIA) injection. Material and Methods Twenty-two consecutive patients were included in this retrospective, IRB-approved study between July and December 2017. CBCT from the aorta and 30° oblique-view DSA from both IIAs were obtained for PA detection. Results of suggested PAs from the semi-automatic vessel detection software after CBCT and IIA DSA were compared. Moreover, dose area product (DAP) was recorded. Statistical analysis included Spearman’s correlation, Mann–Whitney U test, and the Wilcoxon test considering P<0.05 as significant. Results PA type was classified significantly better with CBCT compared to DSA ( P=0.047). In IIA DSA, PAs could not be identified in 18% on the left and in 17% on the right side. CBCT detected all PAs, although truncation occurred in 59% because of the limited field of view. Mean DAP of the whole procedure was 257,161.32±127,909.36 mGy*cm2. Mean DAPs were for a single DSA 14,502.51±9,437.67 mGy*cm2 and for one CBCT 15,589.23±2,722.49 mGy*cm2. A mean of 14.82 DSAs and only one CBCT were performed. CBCT accounted for 6% and DSA for 84% of the entire DAP of the procedure. Conclusion CBCT with semi-automatic feeding vessel detection software detects PAs more accurately than IIA DSA and may reduce radiation dose.
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Acharya, Pradip, G. Ren, MR Jaisani, A. Dongol, RP Yadav, AK Mahat und F. Dong. „Application of cone-beam computed tomography (CBCT) for diagnosis and management of mandibular condyle fractures“. Health Renaissance 13, Nr. 3 (03.08.2017): 73–81. http://dx.doi.org/10.3126/hren.v13i3.17930.
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Background: Cone beam computed tomography (CBCT) provides precise imaging of temporomandibular joint anatomy without superimposition and distortion. CBCT is relatively a new imaging modality and used commonly in dental practice.Objective: The aim of this study is to present detailed imaging of emporomandibular joint in case of condyle fracture using CBCT for its use in diagnosis, surgical planning and evaluation of treatment.Method: In our study, we evaluated 3D - CBCT (three dimensional Cone beam computed tomography) examinations of 18 patients with mandibular condyle fractures. All of the fractures in our cases were overlooked on CBCT, thus providing axial, coronal and para-sagittal imaging of condylar head including 3D dimensional volumetric images of the condyle and surrounding structures.Result: Out of 18 condylar fracture patient’s CBCT, 8 radiographs showed condylar head (intracapsular) fracture, 2 condylar neck, 8 subcondylar fracture. 13 condylar fractures were unilateral and 5 were bilateral fracture. 9 of the condylar fractures were not associated with the mandible fracture. Out of the 9 associated condylar fractures; 3 were associated with symphysis fracture, 4 associated with parasymphysis fracture, 1 associated with body fracture and remaining 1 associated with mandibular angle fracture. 6 of the condylar fracture showed no signs of displacement of the fractured part and among 12 displaced condylar fracture parts 8 medially and 4 laterally displaced recorded in CBCT. All of the patients were given treatment on the basis of CBCT diagnosis and the results obtained from it was clinical satisfactory without complaints.Conclusion: We concluded that CBCT is the latest sophisticated technology which provides clear image of condylar head without superimposition of other structures, presented supplementary information for a more effective diagnosis and management of mandibular condyle fractures. Health Renaissance 2015;13 (3): 73-81
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Kailash, Sahithya. „CBCT's Cone Beam Computed Tomography“. Journal of Academy of Dental Education 1, Nr. 1 (08.01.2014): 9. http://dx.doi.org/10.18311/jade/2014/2423.
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Dental X- Rays are important for diagnosing and treating patients by helping to detect oral health issues when they can't be detected by visual or physical examination alone. Dental X-Ray take a much closer look and provide valuable information in the area of interest. Though 2 Dimensional X-Ray and Panoramic radiography can predict diagnosis in number of clinical cases, certain situations demand multiplanar imaging, one such technology is CBCT. CBCT is a specialised 3Dimensional Craniofacial imaging in which 3 Dimensional reconstruction is possible. The final reconstructed image produced, reveals multilayer images in 3 orthogonal planes (coronal, sagittal and transverse) This article focuses on CBCT and its applications in various fields of dentistry.
Dissertationen zum Thema "CBCT technology"
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Gianquinto, Jared Robert. „A Method of Superimposition of CBCT Volumes in the Posterior Cranial Base“. Master's thesis, Temple University Libraries, 2011. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/210320.
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Oral BiologyM.S.
Three dimensional imaging in the form of Cone Beam Computed Tomography has become prevalent in the field of orthodontics. Analytical methods of resulting volumetric data sets have not kept pace with the technology capable of producing them. Current 3D analysis techniques are largely adaptations of existing 2D methods, offering no clear diagnostic advantage over traditional imaging techniques in light of increased radiation exposure, and cannot be compared with norms generated from 2D image capture sources. In order to study morphology in 3D, data sets must be generated for longitudinal studies and native 3D analytical methods must also be developed. Existing methods of CBCT volume superimposition are cumbersome, involving complex software pipelines and multiple systems to complete the process. The goal of the current study was to develop a reproducible method of CBCT volume superimposition in the posterior cranial base in a single software package, and construct an easy to follow, step-by-step manual to facilitate future studies in craniofacial morphology. Existing anonymized sequential CBCT volumes of three subjects meeting inclusion criteria were obtained from the Kornberg School of Dentistry Department of Radiology. Volumes for each subject were imported into AMIRA software, resampled to a standardized 0.5 mm voxel size and superimposed with a mutual information algorithm. Posterior cranial base surface data was extracted using a semi-automatic technique. Resulting surface distance data was compiled and visualized through application of color maps. A streamlined image processing protocol was produced and documented in a detailed step-by-step manual. Surface distance analysis of serial segmentations was performed to verify reliability of the process. Surface distance deviations greater than 0.5 mm consistently fell below 0.2 percent of the total surface area. Sequential scan superimpositions of all three subjects exhibited mean surface distances of less than 0.15 mm. Two out of three subjects exhibited deviations of greater than 0.5 mm in less than 1 percent of the total surface area, suggesting consistent sub-voxel accuracy of the protocol.
Temple University--Theses
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Ondrová, Martina. „Design dentálního panoramatického rentgenu s 3D zobrazením“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-444989.
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The topic of this thesis is the design of dental X-ray. User problems were identified based on the design and technical analysis for which solutions are presented in the work. The innovative shape and design solution shows a new approach to dental X-rays. The main benefit of the design is the solution to real ergonomic problems that can occur during the interaction of the operator or patient and the device. The design corresponds to current trends in the evolving design field of medical design.
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Octave, Nadia. „La radiothérapie adaptative et guidée par imagerie avec la technologie Cone-Beam CT : mise en oeuvre en vue du traitement de la prostate“. Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30207/document.
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L'imagerie est maintenant partie intégrante des traitements de radiothérapie. Avec la technologie CBCT embarquée sur les appareils de traitement, l'imagerie tomographique permet non seulement de repositionner fidèlement le patient tout au long de son traitement mais aussi d'adapter la planification initiale aux modifications quotidiennes de volume. C'est la radiothérapie adaptative, objet des travaux de cette thèse. Nous avons établi les limites techniques de précision de repositionnement des équipements utilisé. Ensuite, à partir des acquisitions CBCT quotidiennes de patients traités pour la prostate, nous avons élaboré une stratégie de traitement basée sur une banque de plans personnalisés. Nous avons mis au point une méthode semi-automatique de sélection du plan de traitement du jour qui a montré une efficacité supérieure à la sélection par des opérateurs expérimentés. Enfin, nous avons quantifié les doses additionnelles à la dose thérapeutique associées à l'utilisation quotidienne de l'imagerie CBCT. En conclusion, on peut dire qu'avec l'imagerie CBCT embarquée, on peut voir ce que l'on veut traiter, irradier ce que l'on a vu et contrôler ce qu'on a traitéImaging is now fully integrated in the radiation therapy process. With on-board CBCT systems, tomography imaging allows not only patient positioning but also treatment planning adaptation with patient anatomy modifications, throughout the entire treatment. This is called adaptive radiation therapy, and is the main subject of this PhD thesis. During this work, we measured the repositioning accuracy of the system used. We also developed a treatment strategy using daily CBCT images and a personalized plan database to adapt treatment plan to patient anatomy. We found a way to select the daily treatment plan that shows superiority over operator selection. Then we also quantified the additional dose delivered while using this technique and the impact with regards to the risks added to patients. As a conclusion, with CBCT imaging, radiation therapy has entered an era where one can see what need to be treated, can treat what has been seen and can control what has been treated
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Lemammer, Imane. „Calibration en ligne d'un C-arm mobile à l'aide de capteurs inertiels pour des applications en CBCT“. Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALT039.
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Les images acquises par tomographie volumique à faisceaux coniques (CBCT) sont plus précises que celles de la radiologie classique tout en produisant 1.5 à 12 fois moins de rayons X. Ces bonnes précisions en font un outil intéressant ce qui concerne le diagnostic et la planification d’interventions chirurgicales. Ce n'est que récemment que son usage est entré dans la pratique pour des chirurgies lourdes, avec l'introduction de systèmes d'imagerie par radiographie dédiés, coûteux et encombrants. Une idée pour généraliser son utilisation à des chirurgies mineures, en orthopédie ou en traumatologie par exemple, serait de l’implanter sur le dispositif d’imagerie radiologique médicale le plus répandu en salle d’opération : l’arceau chirurgical mobile (C-arm).Cependant, le C-arm est incompatible avec les algorithmes de tomographie volumique de l’état de l’art qui nécessitent une connaissance très précise de la géométrie de l'image. En effet, un C-arm est mécaniquement instable et ses trajectoires sont non répétables. De plus, les algorithmes de calibration géométrique du C-arm mobile de l’état de l’art ne répondent pas aux exigences de cet usage : invasivité, modification trop importante de la routine chirurgicale, précision de localisation insuffisante… Dès lors, nous avons mis en évidence l’intérêt d’implanter une nouvelle méthode de calibration en ligne non invasive du C-arm. Pour ce faire, nous avons choisi d’exploiter principalement des mesures issues de capteurs inertiels.Pour répondre à cette problématique, nous abordons deux points : La construction d’un algorithme de calibration : l’idée est d’estimer la position et l’orientation du couple source-détecteur du C-arm mobile à partir des mesures inertielles et de modèles cinématiques adaptés, et grâce à des estimateurs (filtres et lisseurs de Kalman) correctement paramétrés. La propagation des erreurs d’estimation de positions et d’orientations jusqu’aux projetés 2D puis jusqu’aux reconstructions 3D : le but est d’évaluer l’impact des erreurs de localisation sur la qualité de reconstruction tout en permettant de déterminer les paramètres les plus impactants.Afin de valider le dispositif de calibration proposé, deux plateformes expérimentales ont été construites dans le cadre cette thèse : un bras rotatif qui permet de reproduire les mouvements de la source à rayons X ou du détecteur du C-arm dans le cas de trajectoires simplifiées, motorisées et répétables, et un C-arm réel qui a été sécurisé et motorisé, puis équipé de capteurs. Ce dernier nous a permis d’estimer la précision de localisation du couple source-détecteur pour des trajectoires réalistes.Sur une trajectoire classique d’un système réel, les erreurs maximales de calibration obtenues sont de l’ordre de 2 mm pour les positions et du dixième de degré pour les rotations. Ces résultats sont comparables à ceux obtenus par les méthodes de calibration invasives de l’état de l’art. La qualité de reconstruction a été évaluée sur des projetés 2D sur le plan détecteur puis sur des coupes de reconstructions 3D de mires et de fantômes réels. La précision sur l’orientation obtenue est évaluée comme étant suffisante pour garantir une bonne qualité de reconstruction. La précision sur la position est cependant jugée insuffisante. Néanmoins, les reconstructions obtenues, bien que visuellement déformées, gagneraient à être présentées et évaluées par un spécialiste médical. Les algorithmes de propagation d’erreurs ont également permis de conclure qu’une erreur sur les translations dans le plan de la source et du détecteur du C-arm ont, au moins, 6 fois plus d’impact sur les reconstructions que des erreurs sur les autres paramètres géométriques du C-armCone beam computed tomography (CBCT) is more accurate than conventional radiography with less radiation exposure doses. Hence, it is a very useful complementary tool for diagnosis and surgery planning. Despite the increasing popularity of CBCT, it is mainly restricted to major surgery as it requires the use of expensive and bulky angiography systems which are specially designed to allow 3D tomography. One idea to generalize the use of CBCT to minor surgery - in orthopedics and traumatology for example - would be to introduce it on the most widely used tool for X-ray imaging: the mobile C-arm.Volume reconstruction algorithms require a very precise knowledge of the imaging geometry. Unfortunately, due to mechanical instabilities which lead to non-reproducible motions from run to run mobile C-arms are incompatible with existing tomography algorithms. Therefore, a precise C-arm on-line calibration is essential in order to achieve an accurate volume reconstruction. Existing calibration techniques do not meet these specifications. They are either not precise enough, invasive or involve a major change in the process of performing surgical acts. Therefore, we present a new on-line calibration method for mobile C-arms in order to achieve CBCT. It is based on tracking the detector and the X-ray source of the C-arm and aims to be precise and non-invasive.In order to address this issue, we will discuss two items: The first is the construction of a calibration algorithm: the idea is to estimate the position and the orientation of the detector and the X-ray source of the C-arm using inertial measurements, appropriate kinematic models, and a fitting estimator (Kalman filter and smoother). The second item is the propagation of pose estimation errors to 2D projections and to 3D reconstructions. Thus, we can evaluate the impact of the estimation errors on the reconstruction quality.This thesis also describes two experimental setups which allowed us to test and validate the proposed calibration algorithm. The first tracking experiments were carried out on a rotated-arm. It is a simple motorized mock-up to simulate either the detector or the X-ray source of a mobile C-arm. The rotated-arm exhibits a good position and orientation repeatability. The second platform is a full-size modified mobile C-arm. It includes motorized orbital and axial rotations, mechanical end stops and sensors of different characteristics and accuracies. This second platform allows us to estimate the geometric calibration accuracy on realistic trajectories.During a continuous rotation of the experimental C-arm, we achieve a tracking error of 2 mm for positions and of 0.1° for orientation. These values are comparable with existing invasive calibration algorithms accuracies. The image quality of reconstructed CBCT using the proposed calibration algorithm was evaluated on the 2D projections within the detector plane and also on the 3D reconstruction images of various phantoms. The achieved orientation accuracy is sufficient for CBCT. The position accuracy seems not. However, it may be useful to present the resulting 3D reconstruction images to medical evaluation by a specialist to confirm these conclusions. It also appears that the parameters of C-arm's projective geometry which have the greatest impact on the 2D projections are the in-plane translations of the X-ray source and of the detector. Therefore, they are the most critical parameters to be efficiently tracked in order to avoid artifacts in the 3D volume reconstruction. Compared to in-plane translations, the out-plane translations and the orientation of the detector have little influence on the 2D projections
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Warnock, Sarah M. „Cortical Bone Mechanics Technology (CBMT) and Dual X-Ray Absorptiometry (DXA) Sensitivity to Bone Collagen Degradation in Human Ulna Bone“. Ohio University Honors Tutorial College / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1556305540256918.
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Hanci, Arzu. „The Effect Of Individual Differences On Acceptance Of Web-based Learning Management System: A Case Of The Central Bank Of The Republic Of Turkey“. Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608823/index.pdf.
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The aim of this study is to investigate the effect of Bank employees&rsquoindividual and organization related individual differences on the acceptance of Learning Management System (LMS) in Central Bank of the Republic of Turkey (CBRT). The study aims to find out whether there are differences in perceived ease of use of technology, perceived usefulness of technology, and attitudes toward the use of LMS in terms of Bank employees&rsquo
gender, age, seniority, title, department, and LMS role groups. Survey design was used in this thesis study. Two self-report questionnaires were developed on LMS acceptance for two different LMS role groups. Accordingly, these questionnaires were distributed to department managers, training experts, training researchers, office staff and participants of training programs who have experienced LMS recently in the CBRT. 167 participants, and 64 department managers and office users responded the survey significantly. The data gathered via questionnaires was analyzed with the SPSS program, using descriptive and inferential statistics where correlation analysis and ANOVA were conducted. The results of the study showed that age and seniority of &ldquo
participants&rdquo
affect the participants&rsquo
acceptance of LMS
in particular they affect the perceived usefulness of LMS. Furthermore, the department of &ldquo
department managers and office users&rdquo
affects their acceptance of LMS regarding perceived usefulness, perceived ease of use, and attitudes toward the use of LMS. Consequently, the results of this case study can contribute to the literature regarding the determinants of technology acceptance factors.
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Alsharif, Abdulla H. „Intelligent M-Health-CBT combined technology for an enhanced smoking cessation management system using data mining techniques with a case study in Saudi Arabia“. Thesis, Kingston University, 2016. http://eprints.kingston.ac.uk/37875/.
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Smoking has become one of the major global health concerns. Though there are various awareness activities being undertaken, the prevalence of smoking across the world is increasing at alarming levels. However, the extent of this increase varies among different countries. Even in culturally rich countries where smoking is considered as antagonistic behaviour both religiously and culturally, like Saudi Arabia, the prevalence of smoking is increasing at alarming levels. As smoking is mostly a behavioural aspect bundled with other factors, CBT (Cognitive Behavioural Therapy) integrated with m-health technologies represents a good strategy towards smoking cessation. This study focuses on developing a mobile smoking cessation management system - SMOKE MIND - using CBT intervention, and assessing its impact on achieving smoking cessation. This study uses mixed methods approach, where different methods are used at different stages of the research. Based on the systematic reviews and other literature reviewed, a questionnaire-based survey is conducted to assess the requirements of smokers in Saudi Arabia regarding the system for smoking cessation. The system developed uses CO readings of smokers, entered daily by participants through the mobile application, and assesses their improvement. Additionally, smokers enter CBT data if their CO readings are high, also through the mobile application. Based on these readings and CBT data, physicians recommend various activities and send motivational messages. The system is trailed for four weeks with an intervention group, who had access to the system, and a control group who did not. At the end of the study, another survey is conducted for evaluating the usability aspects of the SMOKE MIND system. The results achieved at the end of the study in evaluating the SMOKE MIND System reflect significant improvements in the participants in quitting smoking, and high satisfaction levels of the participants using the system. The values of p in both one-talied (0.0061) and two tailed (0.01) t-test are < 0.05, indicating that results are significant. 81.8% of the participants in intervention group and 40% participants in the control group quit smoking at the end of the study. A majority of the participants were highly satisfied with the various features used in the SMOKE MIND System.
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Shahzad, Muhammad, und Shahid Javed. „IMPROVING EDUCATION THROUGH E LEARNING“. Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17266.
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Information Communication Technologies (ICT) are taking pace with rapid development,with the strive to impart education among learners in a way that they become highly satisfied.With a help of different electronic tools in educational technology using media and makingright environments to enhance learning, develop creativity, stimulate communication, createchannels for collaboration, and hence, engaging in the continued development and applicationto knowledge and skills. Usage of technology spans across all academic areas with theincreasing popularity of information technology that is evolving rapidly towards bettermentwith increased capabilities every day. Educationalists are interested in knowing howtechnology would create a variation for the students in the classroom. The purpose of using ELearningis to create a learning platform with combination of the existing knowledge andInformation Communication Technologies (ICT). High growth in Information Technology thatis user friendly, accessible, and reliable at the same time providing improved ways incollaborating in a new approach possible. Students from different units would be able tocollaborate forming cross-unit teams and working on common or multiple assignmentshelping each other in different ways. Internet, video conferencing, and emails are wellestablished collaborative tools for exchange of information. Investigating that why there is aneed of technology in the education and which technologies would help in improving learningprocesses is the main purpose of this research. And also to find that what would be thenecessary infrastructure required to get facilitated by this technology. The research revolvesaround the theory of Computer Based Training (CBT) which refers to particular part of theinstructional development or educational media.Program: Magisterutbildning i informatik
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Dunne, Nivek. „Evaluation of psychology clinicians' attitudes towards computerised cognitive behaviour therapy, for use in their future clinical practice, with regard to treating those suffering from anxiety and depression“. Antioch University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1503328670275243.
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Mhlongo, Nanikie Charity, und n/a. „Competency-Based assessment in Australia - does it work?“ University of Canberra. Education and Community Studies, 2002. http://erl.canberra.edu.au./public/adt-AUC20050530.094237.
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South Africa since the liberation in 1994 has faced a lot of changes. The changes
include being a member of the international community. As part of the international
community, South Africa is finding itself largely faced by the challenges associated
with this position. Looking at other countries South Africa is realizing that the world
is looking at better ways of educating their people and organizing their education and
training systems so that they might gain the edge in an increasingly competitive
economic global environment. Success and survival in such a world demands that
South Africa has a national education and training system that provides quality
learning and promotes the development of a nation that is committed to life-long
learning.
Institutions of higher education in South Africa are currently changing their present
education system to conform to a Competency-Based Training (CBT) system. This
system has only been planned but not implemented yet and it is not clear how CBT
will be implemented, especially how the learners are going to be assessed.
Competency-Based Assessment (CBA) is an integral part of CBT that needs
particular attention if the new system is to succeed.
The key aims of this thesis are to investigate the current assessment policy and
practice at the Canberra Institute of Technology (CIT) underpinned by Competency-
Based Training system. The project will describe and analyze the Competency-Based
Assessment system used within CIT's CBT system. The project will focus on:
Observing classroom practice of CBA, analyzing students' and teachers' perceptions
of their involvement with CBA, and analyzing employers' perceptions of the
effectiveness of CBA.
The main aim of this thesis is to suggest recommendations for an assessment model
that will be suitable to implement within hospitality training institutions in South
Africa.
Bücher zum Thema "CBCT technology"
1
Palmer, Richard. What is CBT interactive video? Manchester: NCC Publications, 1987.
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Computer Based Training in der Medizin: Technik - Evaluation - Implementation. Aachen, NRW, Germany: Shaker Verlag, 1998.
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Muroff, Jordana, Abigail Ross und Joseph Rothfarb. Additive and Alternative Approaches to Treating Obsessive Compulsive Disorder. Herausgegeben von Gail Steketee. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780195376210.013.0086.
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While cognitive-behavioral therapy (CBT) and pharmacotherapy are “gold standard” treatments for obsessive-compulsive disorder (OCD), complementary and alternative treatments are frequently sought for anxiety disorders. The purpose of this chapter is to review and discuss the available research on the application, efficacy and effectiveness of complementary and alternative methods for treating OCD. The first section identifies and reviews studies focusing on specific alternative and complementary treatments that are independent from, or work in conjunction with CBT, such as yoga, herbal remedies, motivational strategies, and bibliotherapy. The second section discusses alternative and complementary methods of more mainstream CBT and related techniques, with a particular focus on technology-supported approaches. The chapter concludes with a discussion of the methodological issues in the existing research on complementary and alternative methods in the treatment of OCD, questions for future research, and implications for providers.
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Biomedica: Desde la Perspectiva del Estudiante. Tampa, Fl: Techniciansfriend.com, 2008.
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Minimum Technology Guidance on Double Liner Systems for Landfills and Surface Impoundments (Pb 87-151072 Cbt). Natl Technical Information, 1985.
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Rios, Ruben, Joaquin Garcia-Alfaro, Jordi Herrera-Joancomartí und Giovanni Livraga. Data Privacy Management, Cryptocurrencies and Blockchain Technology: ESORICS 2018 International Workshops, DPM 2018 and CBT 2018, Barcelona, Spain, ... Springer, 2018.
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Data Privacy Management, Cryptocurrencies and Blockchain Technology: ESORICS 2017 International Workshops, DPM 2017 and CBT 2017, Oslo, Norway, ... Springer, 2017.
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Multimedia in Health Sciences Education. Berlin, Germany: Logos-Verlag Berlin, 2001.
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Safren, Steven A., Susan E. Sprich, Carol A. Perlman und Michael W. Otto. Mastering Your Adult ADHD. Oxford University Press, 2017. http://dx.doi.org/10.1093/med:psych/9780190235581.001.0001.
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The treatment program outlined in this book is designed for use by a therapist who is familiar with cognitive-behavioral therapy (CBT). The program helps adult clients with ADHD learn skills to help them cope with their symptoms. Core modules on organizing and planning, reducing distractibility, and adaptive thinking are included, as is an optional module on reducing procrastination. An informational meeting can also be included with a spouse, partner, or family member. The guide concludes with a discussion of how to help the client handle slips and maintain the gains made in treatment. This revised version of the therapist guide incorporates many changes from the first edition, including an enhanced discussion of how to incorporate technology into the treatment and new “signposts of change” sections in each chapter.
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Ferguson, Robert, und Karen Gillock. Memory and Attention Adaptation Training. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197521526.001.0001.
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Memory and Attention Adaptation Training (MAAT) is a cognitive-behavioral therapy (CBT) designed to help cancer survivors self-manage and mitigate the late and long-term effects of cancer and cancer therapy on memory function. Cancer-related cognitive impairment (CRCI) is a set of mild to moderate memory and attention impairments that can have an adverse influence on quality of life. CRCI symptoms tend to present during active treatment, but for some individuals cognitive changes can persist for years. While the exact prevalence of CRCI is unknown, review of the literature estimates that nearly half of all survivors may experience some form of CRCI. Causes of CRCI are multiple and are the subject of continued research. Chemotherapy, genetic vulnerability, neurovascular damage, inflammation, and hormonal/endocrine disruption have all been identified as candidate mechanisms of persistent cognitive change. Given the multiple causal mechanisms, finding a biomedical treatment for CRCI remains elusive. MAAT was developed as a CBT to help cancer survivors make adaptive behavioral and cognitive changes to improve performance in the valued activities that CRCI hinders. MAAT consists of eight visits and has been designed for administration through telehealth technology, improving access to the survivorship care that so many cancer survivors may lack after the time and expense of cancer treatment. Survivors can use this workbook to reinforce their in-session learning and continue to build adaptive coping.
Buchteile zum Thema "CBCT technology"
1
Johari, Rahul, Kanika Gupta, Saurabh Kumar Jha und Vivek Kumar. „CBCT: CryptoCurrency Based Blockchain Technology“. In Data Science and Analytics, 90–99. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5830-6_8.
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Grant, Gerald T., Jayanthi Parthasarathy, Shivakumar Raman, Bruno Azevedo und William C. Scarfe. „CBCT and Additive Manufacturing Technology“. In Maxillofacial Cone Beam Computed Tomography, 1207–42. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-62061-9_31.
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Luminati, Tito, und Eugenio Tagliafico. „CBCT Systems and Imaging Technology“. In Cone Beam CT and 3D imaging, 1–12. Milano: Springer Milan, 2013. http://dx.doi.org/10.1007/978-88-470-5319-9_1.
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Rathi, Shikha, und David Hatcher. „Radiographic Evaluation of the Alveolar Ridge in Implant Dentistry. CBCT Technology“. In Horizontal Alveolar Ridge Augmentation in Implant Dentistry: A Surgical Manual, 55–71. Hoboken, New Jersey: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119019916.ch06.
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Dalle Grave, Riccardo, Massimiliano Sartirana, Marwan El Ghoch und Simona Calugi. „CBT-OB and Digital Technology“. In Treating Obesity with Personalized Cognitive Behavioral Therapy, 221–27. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-91497-8_15.
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Codd, R. Trent. „TECHNOLOGY IN CBT TRAINING AND SUPERVISION“. In Teaching and Supervising Cognitive Behavioral Therapy, 121–32. Hoboken, New Jersey: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119179948.ch07.
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Gavrila, Monica, und Natalia Elita. „Comparing CBMT Approaches for German-Romanian“. In Human Language Technology Challenges for Computer Science and Linguistics, 445–55. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-14120-6_36.
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Kurokawa, Takashi, Ryo Nojima und Shiho Moriai. „Can We Securely Use CBC Mode in TLS1.0?“ In Information and Communication Technology, 151–60. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-24315-3_15.
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Yoo, Kwang Kiun, und Ronny Yongho Kim. „HiNet: Radio Frequency Communication Based Train Control (RF-CBTC) System Jointly Using Hierarchical Modulation and Network Coding“. In Convergence and Hybrid Information Technology, 130–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-32645-5_17.
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„Comparison of CT and CBCT for fabrication of dentistry models via rapid prototyping technology“. In Innovative Developments in Design and Manufacturing, 119–28. CRC Press, 2009. http://dx.doi.org/10.1201/9780203859476-21.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "CBCT technology"
1
Wicaksono, Aryo, Agung Harsoyo und Ary Setijadi Prihatmanto. „Three dimensions medical CBCT reconstruction and visualisation analysis“. In 2012 International Conference on System Engineering and Technology (ICSET). IEEE, 2012. http://dx.doi.org/10.1109/icsengt.2012.6339338.
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Pavaloiu, Ionel-Bujorel, Nicolae Goga, Andrei Vasilateanu und Iuliana Marin. „3D RECONSTRUCTION FROM CBCT DATA USED IN DENTISTRY LEARNING“. In International Technology, Education and Development Conference. IATED, 2016. http://dx.doi.org/10.21125/iceri.2016.2196.
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3
Yichen, Xie, Chen Jian, Yan Bin, Zeng Lei, Tong Li und Zeng Yin. „A seam-line removal method on mosaicing of CBCT images“. In 2012 2nd International Conference on Computer Science and Network Technology (ICCSNT). IEEE, 2012. http://dx.doi.org/10.1109/iccsnt.2012.6525887.
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Thakur, Anita, Mayank Malik, Nishtha Phutela, P. K. Khare und Prashant Mor. „CBCT image noise reduction and enhancement using Bi-Histogram method with bent activation function“. In 2016 International Conference on Information Technology (InCITe): Next-Generation IT Summit on the Theme "Internet of Things: Connect Your Worlds". IEEE, 2016. http://dx.doi.org/10.1109/incite.2016.7857624.
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El-Genk, Mohamed S., und Jean-Michel Tournier. „Performance Comparison of VHTR Plants With Direct and Indirect Energy Conversion Cycles“. In Fourth International Topical Meeting on High Temperature Reactor Technology. ASMEDC, 2008. http://dx.doi.org/10.1115/htr2008-58276.
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This paper compared the performance of very high temperature reactor (VHTR) plants with direct and indirect closed Brayton Cycles (CBCs) and investigated the effect of the molecular weight of the CBC working fluid on the number of stages in and the size of the single shaft turbomachines. The CBC working fluids considered are helium (4 g/mole) and He-Xe and He-N2 binary mixtures (15 g/mole). Also investigated are the effects of using LPC and HPC with inter-cooling, cooling the reactor pressure vessel with He bled off at the exit of the compressor, and changing the reactor exit temperature from 700°C to 950°C on the plant thermal efficiency, CBC pressure ratio and the number of stages in and size of the turbo-machines. Analyses are performed for reactor thermal power of 600 MW, shaft rotation speed of 3000 rpm, and IHX temperature pinch of 50 °C.
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Keevill, Dave. „Communication Based Train Control Technology Selection“. In 2014 Joint Rail Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/jrc2014-3705.
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You have selected Communications-Based Train Control (CBTC) for your new transit line, or as an upgrade to the signaling system on your existing rail network. You look forward with anticipation to the benefits it will bring your agency in terms of capacity, safety and reliability. You plan to release your Request for Proposals to the street and then sit back and watch a pack of ravenous CBTC system suppliers pounce on it, eager to make all your signaling dreams come true. But how do you ensure consistency among the offers, to enable you to select the right system for your operation? How do you specify a system that can reasonably be delivered within your budget and schedule constraints? Should you evaluate based on capital or life cycle cost? What bid evaluation criteria should you employ? There are so many factors to consider: tried and true technology vs. cutting edge; an off-the-shelf solution vs. one customized to the exacting specifications of your Operations and Maintenance departments; the degree to which redundancy should be built into the system; readiness to integrate with other support systems, like the data communications backbone or SCADA. Is one CBTC system architecture a better fit for your property, or is it “six of one, half a dozen of the other”? This paper will address the technical components of these factors, to assist you in selecting the right technology for your CBTC deployment.
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Diemunsch, Kenneth M., und Daniel J. Reitz. „Consequences of Failed Track Circuits on Conventional Signaling System in CBTC Projects“. In 2013 Joint Rail Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/jrc2013-2515.
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In recent years, many rapid mass transit agencies have chosen Communication Based Train Control (CBTC) technology to refurbish their signaling system or to equip a new line. CBTC technology is a type of Automatic Train Control (ATC) that allows transit agencies to increase nominal throughput and to improve safety. The main functions of CBTC are described in [1.] and [2.]. This technology can operate without fixed wayside track detectors such as track circuits. However, track circuit equipment continues to be implemented on the tracks and in the equipment rooms. For authorities under the Federal Railroad Administration, current regulations require use of track circuit but the main functional reason is to have a backup system in case of CBTC failure. Most transit agencies decide to include track circuit occupied and vacant status into the CBTC system in order to enhance safety. How to enhance safety and keep train operation efficient during track circuit failure is a challenge for CBTC projects. This paper discusses the relationship between the CBTC and the conventional interlocking system when track circuit failure occurs. The analysis in this paper applies to both relay and solid state interlocking systems as both technologies have to deal with the same impact under this scenario. The method of detection of track circuit failure by the CBTC system and the possible restrictions on CBTC train operation are not presented. The paper focuses on the interface between the CBTC and the signaling system. It begins by introducing the different types of track circuit failures and their consequences on conventional signaling system to address and compare multiple scenarios. Then, the paper discusses how the CBTC system can affect the conventional signaling system equipment, such as signals and train stops, once it has detected a track circuit failure. Transit agencies’ different possible approaches to manage track circuits failures within the context of an operating CBTC system are explained.
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Diemunsch, Kenneth, und Nagaratnam Rabindran. „Origins and Current Status of the Different Communications-Based Train Control Products“. In 2020 Joint Rail Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/jrc2020-8020.
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Abstract Communications-Based Train Control (CBTC) technology is used by transit agencies in large cities to maximize the use of their infrastructure. In comparison with conventional block signal system and cab signaling system, CBTC provides the most efficient capabilities with respect to headway and throughput while being the most economical in terms of maintenance cost [1]. CBTC also provides better diagnostic capabilities compared to traditional signaling systems. It uses limited number of equipment on the trackside compared to traditional signaling systems and allows either a centralized architecture or distributed architecture. For these reasons, CBTC is now the favored system for new lines as well as most signaling system renewals.[1] Despite widely used CBTC standards, the signaling industry is not in agreement regarding what qualifies as a CBTC system and which projects are the first “real” CBTC projects. This work describes the different CBTC vendors, their genesis, when access point based radio was first introduced (access point based radio is also referred by signaling engineers as free space propagation radio), the different consolidations with other CBTC companies, and their major projects. From the authors’ viewpoint, it is appropriate to present the CBTC vendors by geographical areas, for instance in North America: Bombardier Transportation, Thales Rail Signaling Solutions, in Europe: Alstom Transport, Hitachi Rail, Siemens Mobility, in Asia: Beijing Traffic Control Technology, China Railway Signal and Communications, Mitsubishi Electric Corporation, and Nippon Signals.
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Hofbauer, John. „Challenges With Applying Axle Counter Technology in the USA“. In 2017 Joint Rail Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/jrc2017-2293.
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There is a growing trend for transit agencies to evolve from wayside and cab-based signal systems to Communication Based Train Control (CBTC). With the complexity of CBTC, a failure of CBTC component could bring a transit system to a standstill. Implementing a secondary signal system can serve to minimize the consequences of a CBTC failure. It is paramount for a transit system to continue to operate, and axle counter technology can be a suitable candidate for use as a secondary signal system. Axle Counter technology has not been widely used in the U.S., but has been used for many years in Europe and the rest of the world. This paper will review and analysis the following: 1. Train Detection Systems; Track circuits vs. axle counters and the basic Principles of Axle Counting; check-in and check-out. 2. Implementing Electromagnetic Compatibility and the EMI standards used in European with previous testing of various axle counter systems, and the frequencies that have been selected, and the proper usage of these frequencies. 3. Testing of radiated emissions using existing guidelines and methods to analyze existing wayside and vehicle Electromagnetic Interferences (EMI), environment conditions, and the limitations of installing axle counters in an existing rail or transit system. 4. Recommendations for improving vehicle and wayside specifications and standards within the U.S. for dealing with installation of axle counter equipment and with failures and EMI emissions between railway devices.
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Aguado, Marina, Oscar Onandi, Eduardo Jacob, Christian Pinedo, Purificacion Saiz und Marivi Higuero. „WiMAX Role on CBTC Systems“. In ASME/IEEE 2007 Joint Rail Conference and Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/jrc/ice2007-40103.
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The recent progresses in mobile telecommunications technologies have allowed railway telecommunications technology to go a step forward, and, in the same way, the railway control systems. In this sense, while the mobile telecommunications technology evolved from the first generation of analogue mobile communication systems to what is known today as B3G (Beyond 3G), the same occurred with the telecommunication systems used in railways, from those based on analogue telecommunications, to the most recent ones based on 2G such as GSM-R or TETRA. Till recently, there was a technological gap regarding high mobility environments, high transmission rate and high interactivity (low latency). However, new emerging telecommunications technologies have shortened this gap significantly. This way, the train control systems will be affected by the availability of telecommunications technologies capable of offering earth-train broadband communications in real time. This article presents a telecommunications network architecture based on WiMAX (Worldwide Interoperability for Microwave Access) mobile technology (IEEE 802.16e) that fulfils the telecommunications needs in the railway environment. The WiMAX mobile technology most relevant features are: transmission rates up to 30Mbps at 15 km distance; mobility support up to 200km/h; QoS, security, low latency, fast, scalable and cost effective deployment, mainly compared to GSM-R deployment. In the mobile node design of this network telecommunications architecture, the multipath fading effect, and the Doppler effect, present in high speed mobility scenarios, have been taken into account. An improvement in the handoff between BSs, through a neighbouring and predictive mobility algorithm, is included. The architecture proposed supports the functional and system requirements identified in the UIC Project EIRENE (European Integrated Railway Radio Enhanced Network), and demanded to GSM-R technology. Measures on a real testbed and a model developed with the discrete event simulation tool, Opnet, have been employed in this work.