教学课程资源库 更多>>

关键词： oro-antral fistula   turbinate stitch   Ahmed's three layer flap  

关键词： Craniometric   Decompressive hemicraniectomy (DHC)   Intracerebral hemorrhage (ICH)   Minimally invasive parafascicular surgery (MIPS)   Port   Subcortical  

摘要： BACKGROUND: Intracerebral hemorrhage (ICH) is a neurosurgical emergency. Combined decompressive hemicraniectomy (DHC) and minimally invasive parafascicular surgery (MIPS) may provide a practical method of managing subcortical ICH. OBJECTIVE: 1) To present a case series of combined DHC-MIPS for the treatment of subcortical-based ICH;2) to describe technical nuances of DHC-MIPS;and 3) to provide a literature overview of MIPS for ICH. METHODS: The following inclusion criteria were used: 1) Glasgow Coma Scale (GCS) score <3-4;2) admission within 6 hours of onset;3) increased intracranial pressure caused by hemorrhage;4) patient unresponsive to medical management;5) hemorrhage >30 cm(3);6) subcortical location;and 7) midline shift (mm). Before DHC, sulcal cannulation used the following coordinates: intersection of tragus-frontal bone and midpoint of midpupillary line and midline;corona! suture: 3-4 cm posterior to this point). RESULTS: Three patients were selected: a 62-year old woman, a 45-year old woman, and a 36-year-old man. GCS and ICH scores on admission were 7 and 3, 3 and 4, and 3 and 4, respectively. ICH was located in left basal ganglia in patients 1 and 3 and right basal ganglia in patient 2, all with intraventricular extension. ICH volume was 81.7, 68.2, and 42.3 cm(3), respectively. The postoperative GCS score was 11, 10, and 6, respectively. There were no intraoperative complications or mortalities. Evacuation was within 15 minutes in all patients. The modified Rankin Scale score was 3, 4, and 5, respectively, with semi-independence in case 1. CONCLUSIONS: Combined DHC-MIPS, with the use of craniometric points, can provide a unique and simple surgical option for the management of subcortical ICH.

关键词： Scientific interest   Surgical education   Surgical training  

摘要： The scientific interest (SI) for a given field can be ascertained by quantifying the volume of published research. We quantified the SI in surgical education to clarify the extent of worldwide efforts on this crucial factor required to improve health-care systems. A set of Medical Subject Headings (MeSH) was defined for the PubMed search. The number of Pubmed Indexed Papers (nPIP) relevant to the SI was extracted from database conception to December 2016 and their distribution and evolution by country were analyzed at 10-year intervals. Population Adjusted Index (PAI) and Medical School Adjusted Index (MSAI) analyses were performed for countries with the nPIP > 30. We identified 51,713 articles written in 33 different languages related to surgical education;87.6% of these were written in English. General surgery was the leading surgical specialty. The overall nPIP doubled every 10 years from 1987 (from 6009 to 13,501, to 26,272) but stabilized at 3707, 3800 and 3433 in the past 3 years, respectively. The PAI and MSAI analyses showed that the USA, United Kingdom, New Zealand, Canada, Australia and Ireland are top producers of published research in surgical education, constituting a combined 62.88% of the nPIP. Our quantification of the change in SI in surgical education and training gives a clear picture of evolution, efforts and leadership worldwide over time. This picture mirrors an international academic society that should encourage all those involved in surgical education to improve efforts in educational research.

关键词： TEM   Soot   Aggregate morphology   Particle size distribution k-means   Machine learning  

摘要： This note describes a new approach to identifying soot aggregates in transmission electron microscopy images using k-means clustering. As k-means generally performs poorly for images with noise or gradients, segmenting the image first requires image pre- and post-processing methods, including background removal, denoising, a measure of image texture, and an adjusted threshold binary image. Three pre-processed versions of the image are compiled into feature layers prior to segmentation using k-means. A rolling ball transform is applied post hoc to improve the accuracy of the resultant segmentations. Results are compared to those using a largely-manual method, wherein the threshold is adjusted with a slider in a GUI;automatic Otsu thresholding with a rolling ball transformation;and trainable WEKA segmentation via Fiji.

关键词： dental education   digital real-time evaluation system   preclinical training   tooth preparation  

摘要： Background With the rapid development of technology, traditional dental education has undergone a transition with the active incorporation of digital technology into curricula. DCARER is a recently developed digital real-time evaluation system for the digital assessment of student preclinical simulation practice performance. The system provides supplementary feedback on process analysis in addition to an objective final result. This study evaluated the grading validity of the DCARER system and its effect on dental preclinical practice skills training. Methods Seventy-three residents of Grade 2018, all of whom had completed their 3-year term residencies in standardised and systematic training, were recruited into this study to examine the system's grading validity. All performed crown preparations with the adoption of the DCARER system, which generated both process and final scores. Three experts gave their own grade anonymously according to the final work. The differences between the digital system and the expert scores were analysed. In addition, 60 dental students in Grade 4 and 10 dental faculty members were randomly divided into traditional and digital groups. The students in the traditional group prepared the tooth with the guidance of supervisors, whilst the digital group used the DCARER system. After the class, the students' tooth preparations were scored by the same three experts in a blinded manner. The students and faculty members completed two different sets of questionnaires to evaluate the effects of teaching, acceptance, satisfaction, and evaluation accuracy of the digital system and the traditional method. Results The grading validity assessment showed no significant difference between the tooth preparation scores given by the DCARER system and the experts (P> .05). The unique process scores given by the DCARER system were weakly correlated with the final scores given by both the digital system and the experts. The main characteristics of the 60 stude

关键词： MRI guidance   organ motion modeling   radiotherapy  

摘要： Purpose To develop a method for continuous online dose accumulation during irradiation in MRI-guided radiation therapy (MRgRT) and to demonstrate its application in evaluating the impact of internal organ motion on cumulative dose. Methods An intensity-modulated radiation therapy (IMRT) treatment plan is partitioned into its unique apertures. Dose for each planned aperture is calculated using Monte Carlo dose simulation on each phase of a four-dimensional computed tomography (4D-CT) dataset. Deformable image registration is then performed both (a) between each frame of a cine-MRI acquisition obtained during treatment and a reference frame, and (b) between each volume of the 4D-CT phases and a reference phase. These registrations are used to associate each cine image with a 4D-CT phase. Additionally, for each 4D-CT phase, the deformation vector field (DVF) is used to warp the pre-calculated dose volumes per aperture onto the reference CT dataset. To estimate the dose volume delivered during each frame of the cine-MRI acquisition, we retrieve the pre-calculated warped dose volume for the delivered aperture on the associated 4D-CT phase and adjust it by a rigid translation to account for baseline drift and instances where motion on the cine image exceeds the amplitude observed between 4D-CT phases. Results The proposed dose accumulation method is retrospectively applied to a liver cancer case previously treated on an MRgRT platform. Cumulative dose estimated for free-breathing and respiration-gated delivery is compared against dose calculated on static anatomy. In this sample case, the target minimum dose and D98 varied by as much as 5% and 7%, respectively. Conclusion We demonstrate a technique suitable for continuous online dose accumulation during MRgRT. In contrast to other approaches, dose is pre-calculated per aperture and phase and then retrieved based on a mapping scheme between cine MRI and 4D-CT datasets, aiming at reducing the computational burden for potent

关键词： Dual-energy CT   Iterative reconstruction   Radiation dose   Image quality  

摘要： Purpose: To assess the quality of images obtained on a dual energy computed tomography (CT) scanner. Methods: Image quality was assessed on a 64 detector-row fast kVp-switching dual energy CT scanner (Revolution GSI, GE Medical Systems). The Catphan phantom and a low contrast resolution phantom were employed. Acquisitions were performed at eight different radiation dose levels that ranged from 9 mGy to 32 mGy. Virtual monochromatic spectral images (VMI) were reconstructed in the 40-140 keV range using all available kernels and iterative reconstruction (IR) at four different blending levels. Modulation Transfer Function (MTF) curves, image noise, image contrast, noise power spectrum and contrast to noise ratio were assessed. Results: In-plane spatial resolution at the 10% of the MTF curve was 0.60 mm(-1). In-plane spatial resolution was not modified with VMI energy and IR blending level. Image noise was reduced from 16.6 at 9 mGy to 6.7 at 32 mGy, while peak frequency remained within 0.14 +/- 0.01 mm(-1). Image noise was reduced from 14.3 at IR 10% to 11.5 at IR 50% at a constant peak frequency. The lowest image noise and maximum peak frequency were recorded at 70 keV. Conclusions: Our results have shown how objective image quality is varied when different levels of radiation dose and different settings in IR are applied. These results provide CT operators an in depth understanding of the imaging performance characteristics in dual energy CT.

摘要： This report describes the case of a 5-year-old male with intractable hydrocephalus secondary to neonatal intraventricular hemorrhage who was ultimately managed with the placement of a ventriculo-ureteral (VU) shunt. He had previously failed numerous attempts at cerebrospinal fluid shunting, choroid plexus cauterization, and endoscopic third ventriculostomy. The patient had a history of end stage renal disease, and had previously undergone renal transplant. In an operation that involved Neurosurgeons, Pediatric Urologists, and Transplant surgeons, a Gibson incision was used to avoid the patient's multiple intra-abdominal adhesions, and his nonfunctioning renal unit was used to implant a VU shunt without early or late complications. Published by Elsevier Inc.

关键词： First-order plus time-delay system   Actuator rate limit   System identification   Delay   Reaction curve  

摘要： While actuator rate limit is common and counted in practical engineering, it has not drawn enough attention in control synthesis especially system identification. In this note, it aims to construct a new identification framework for first-order plus time-delay (FOPTD) systems affected by actuator rate limit. It is found that the rate limit can lead to an illusory delay in system reaction curves. Furthermore, necessary quantitative analyses are given to validate that excessively estimated or illusory delay significantly influences estimation accuracy of other parameters and subsequently degrades control performance. Two illustrative examples and experimental results are provided to demonstrate the adverse effect of actuator rate limit on system identification and the effectiveness of the proposed model structure on control performance . (C) 2021 ISA. Published by Elsevier Ltd. All rights reserved.

关键词： Device   Omnidirectional   Retractor   Technique   Craniotomy   Neurosurgery  

摘要： In neurosurgical operations, proper craniotomy using retractors is necessary. Various surgical instruments are used for this purpose, including standard retractors and multipurpose head frame retractor systems. However, the conventional multipurpose head frame system is often not optimal for use in some craniotomies and postures because of its size and complexity of setting. We have invented a new omnidirectional tin-alloyed (ODT) ring retractor for craniotomy with malleability and shape memory characteristics to resolve these issues. It is principally elliptical in shape, approximately 30 x 20 cm in diameter, and sufficiently firm. Accordingly, this ODT ring can retract the surgical field in all directions. Here, we report our experiences of 281 neurosurgical craniotomies using this ODT ring retractor system in various craniotomy sites and postures. Our novel ODT ring retractor is useful because of its low profile, multidirectional retractability, and less obstructiveness with its malleability. It could be used with pediatric patients where strong traction is not desirable.