14 results on '"Hung, Geoffrey"'
Search Results
2. Effects of optically imposed astigmatism on early eye growth in chicks.
- Author
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Chin Hung Geoffrey Chu and Chea Su Kee
- Subjects
Medicine ,Science - Abstract
PURPOSE:To determine the effects of optically imposed astigmatism on early eye growth in chicks. METHODS:5-day-old (P5) White Leghorn chicks were randomly assigned to either wear, monocularly, a "high magnitude" (H: +4.00DS/-8.00DC) crossed-cylindrical lens oriented at one of four axes (45, 90, 135, and 180; n = 20 in each group), or were left untreated (controls; n = 8). Two additional groups wore a "low magnitude" (L: +2.00DS/-4.00DC) cylindrical lens orientated at either axis 90 or 180 (n = 20 and n = 18, respectively). Refractions were measured at P5 and after 7 days of treatment for all chicks (P12), whereas videokeratography and ex-vivo eyeshape analysis were performed at P12 for a subset of chicks in each group (n = 8). RESULTS:Compared to controls, chicks in the treatment groups developed significant amounts of refractive astigmatism (controls: 0.03 ± 0.22DC; treatment groups: 1.34 ± 0.22DC to 5.51 ± 0.26DC, one-way ANOVAs, p ≤ 0.05) with axes compensatory to those imposed by the cylindrical lenses. H cylindrical lenses induced more refractive astigmatism than L lenses (H90 vs. L90: 5.51 ± 0.26D vs. 4.10 ± 0.16D; H180 vs. L180: 2.84 ± 0.44D vs. 1.34 ± 0.22D, unpaired two-sample t-tests, both p ≤ 0.01); and imposing with-the-rule (H90 and L90) and against-the-rule astigmatisms (H180 and L180) resulted in, respectively, steeper and flatter corneal shape. Both corneal and internal astigmatisms were moderately to strongly correlated with refractive astigmatisms (Pearson's r: +0.61 to +0.94, all p ≤ 0.001). In addition, the characteristics of astigmatism were significantly correlated with multiple eyeshape parameters at the posterior segments (Pearson's r: -0.27 to +0.45, all p ≤ 0.05). CONCLUSIONS:Chicks showed compensatory ocular changes in response to the astigmatic magnitudes imposed in this study. The correlations of changes in refractive, corneal, and posterior eyeshape indicate the involvement of anterior and posterior ocular segments during the development of astigmatism.
- Published
- 2015
- Full Text
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3. Bi-directional corneal accommodation in alert chicks with experimentally-induced astigmatism
- Author
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Chu, Chin-hung Geoffrey, Zhou, Yongjin, Zheng, Yongping, and Kee, Chea-su
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- 2014
- Full Text
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4. The TACTIC: development and validation of the Tool for Assessing Chest Tube Insertion Competency.
- Author
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Shefrin, Allan Evan, Khazei, Afshin, Hung, Geoffrey Robert, Odendal, Lisa Teres, and Cheng, Adam
- Subjects
CONFIDENCE intervals ,EMERGENCY physicians ,EXPERIMENTAL design ,LONGITUDINAL method ,RESEARCH methodology ,PEDIATRICS ,QUESTIONNAIRES ,RESEARCH evaluation ,SCALE analysis (Psychology) ,JOB performance ,INTER-observer reliability ,MULTITRAIT multimethod techniques ,RESEARCH methodology evaluation ,CHEST tubes ,DESCRIPTIVE statistics - Abstract
Copyright of CJEM: Canadian Journal of Emergency Medicine is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2015
- Full Text
- View/download PDF
5. Effects of Optically Imposed Astigmatism on Early Eye Growth in Chicks.
- Author
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Chu, Chin Hung Geoffrey and Kee, Chea Su
- Subjects
- *
POULTRY growth , *ASTIGMATISM (Optics) , *REFRACTIVE index , *CONTACT lenses , *POSTERIOR segment (Eye) - Abstract
Purpose: To determine the effects of optically imposed astigmatism on early eye growth in chicks. Methods: 5-day-old (P5) White Leghorn chicks were randomly assigned to either wear, monocularly, a “high magnitude” (H: +4.00DS/-8.00DC) crossed-cylindrical lens oriented at one of four axes (45, 90, 135, and 180; n = 20 in each group), or were left untreated (controls; n = 8). Two additional groups wore a “low magnitude” (L: +2.00DS/−4.00DC) cylindrical lens orientated at either axis 90 or 180 (n = 20 and n = 18, respectively). Refractions were measured at P5 and after 7 days of treatment for all chicks (P12), whereas videokeratography and ex-vivo eyeshape analysis were performed at P12 for a subset of chicks in each group (n = 8). Results: Compared to controls, chicks in the treatment groups developed significant amounts of refractive astigmatism (controls: 0.03±0.22DC; treatment groups: 1.34±0.22DC to 5.51±0.26DC, one-way ANOVAs, p≤0.05) with axes compensatory to those imposed by the cylindrical lenses. H cylindrical lenses induced more refractive astigmatism than L lenses (H90 vs. L90: 5.51±0.26D vs. 4.10±0.16D; H180 vs. L180: 2.84±0.44D vs. 1.34±0.22D, unpaired two-sample t-tests, both p≤0.01); and imposing with-the-rule (H90 and L90) and against-the-rule astigmatisms (H180 and L180) resulted in, respectively, steeper and flatter corneal shape. Both corneal and internal astigmatisms were moderately to strongly correlated with refractive astigmatisms (Pearson’s r: +0.61 to +0.94, all p≤0.001). In addition, the characteristics of astigmatism were significantly correlated with multiple eyeshape parameters at the posterior segments (Pearson’s r: -0.27 to +0.45, all p≤0.05). Conclusions: Chicks showed compensatory ocular changes in response to the astigmatic magnitudes imposed in this study. The correlations of changes in refractive, corneal, and posterior eyeshape indicate the involvement of anterior and posterior ocular segments during the development of astigmatism. [ABSTRACT FROM AUTHOR]
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- 2015
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6. Pediatric Emergency Medicine Fellows Education Day: Addressing CanMEDS objectives at a national subspecialty conference.
- Author
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Hung, Geoffrey R., Bialy, Liza, and Cheng, Adam
- Subjects
- *
CONFERENCES & conventions , *CURRICULUM planning , *EMERGENCY medicine , *GOAL (Psychology) , *HOSPITAL medical staff , *NEEDS assessment , *QUESTIONNAIRES , *SCALE analysis (Psychology) , *SPECIAL days , *CLINICAL competence , *COURSE evaluation (Education) , *DATA analysis software , *DESCRIPTIVE statistics , *EDUCATION ,PLANNING techniques - Abstract
Canadian subspecialty residency training programs are developed around the learning objectives listed in the seven Canadian Medical Education Directives for Specialists (CanMEDS) criteria. Delivering content on objectives outside of those traditionally acquired in clinical rotations can be a challenge. In the present article, the planning process, curriculum development, and evaluation and assessment of a national subspecialty conference model in providing CanMEDS objective-based content sessions in the categories other than Medical Expert (Professional, Scholar, Communicator, Collaborator, Manager and Health Advocate) is described. It is hypothesized that the development of a CanMEDS objective-based curriculum would be positively received by subspecialty residents attending this conference. Attendees of sessions in a two-year curriculum cycle assessed the content as valuable, relevant and effective. The application of this process can be useful to other subspecialty residency training programs to meet the needs of their CanMEDS objective-based training requirements. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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7. Bi-directional corneal accommodation in alert chicks with experimentally-induced astigmatism
- Author
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Chea-Su Kee, Yongping Zheng, Yongjin Zhou, and Chin hung Geoffrey Chu
- Subjects
medicine.medical_specialty ,Biometry ,genetic structures ,Astigmatism ,Refraction, Ocular ,Cornea ,Optics ,Ophthalmology ,Medicine ,Animals ,Cornea curvature ,Analysis of Variance ,Corneal curvature ,business.industry ,Accommodation, Ocular ,medicine.disease ,Sensory Systems ,eye diseases ,Disease Models, Animal ,Corneal accommodation ,sense organs ,Corneal videokeratography system ,business ,Accommodation ,Chickens - Abstract
This study aimed to characterize corneal accommodation in alert chicks with and without experimentally-induced astigmatism. Refraction and corneal biometry were measured in 16 chicks with experimentally-induced astigmatism (1.00 D) and 6 age-matched control chicks (astigmatism ⩽ 1.00 D). Corneal accommodation was detected using a Placido-ring based videokeratography system, by measuring changes in corneal curvature from a series of consecutive images acquired from alert chicks. The correlation between the magnitudes of corneal accommodation and astigmatism was analyzed by including data from all 22 chicks. Data from all eyes showed obvious bi-directional changes in corneal accommodation. There was no significant difference in corneal accommodative changes between the fellow eyes of the treated birds, and the right and left eyes of control birds. However, positive accommodation (PA) and maximum magnitude of PA (MPA) were significantly higher in the astigmatic vs. the fellow eyes of treated chicks (mean ± SE: PA=+2.24 ± 0.44 D vs. +1.26 ± 0.20 D; MPA=+7.53 ± 0.81 D vs. +4.38 ± 0.53 D, both p0.05). This was not the case for negative accommodation (NA) or maximum magnitude of NA (MNA) (NA=-0.46 ± 0.15 D vs. -0.33 ± 0.04 D; MNA=-0.92 ± 0.23 D vs. -0.73 ± 0.12D, respectively, p0.05). Furthermore, higher PA and MPA were found to be correlated with higher refractive astigmatism (both r=0.34, p0.05). These results suggest that the presence of astigmatism may interfere with accommodative function in chicks.
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8. Assessment of the reliability of active radiofrequency identification technology for patient tracking in the pediatric emergency department.
- Author
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Hung, Geoffrey R and Doan, Quynh
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- 2013
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9. A Systematic Review of Patient Tracking Systems for Use in the Pediatric Emergency Department
- Author
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Dobson, Ian, Doan, Quynh, and Hung, Geoffrey
- Subjects
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SYSTEMATIC reviews , *PATIENT monitoring , *PEDIATRIC emergencies , *UTILIZATION of emergency medical services , *CRITICALLY ill children , *EMERGENCY physicians , *HOSPITAL overcrowding , *HOSPITAL administration - Abstract
Abstract: Background: Patient safety is of great importance in the pediatric emergency department (PED). The combination of acutely and critically ill patients and high patient volumes creates a need for systems to support physicians in making accurate and timely diagnoses. Electronic patient tracking systems can potentially improve PED safety by reducing overcrowding and enhancing security. Objectives: To enhance our understanding of current electronic tracking technologies, how they are implemented in a clinical setting, and resulting effect on patient care outcomes including patient safety. Methods: Nine databases were searched. Two independent reviewers identified articles that contained reference to patient tracking technologies in pediatrics or emergency medicine. Quantitative studies were assessed independently for methodological strength by two reviewers using an external assessment tool. Results: Of 2292 initial articles, 22 were deemed relevant. Seventeen were qualitative, and the remaining five quantitative articles were assessed as being methodologically weak. Existing patient tracking systems in the ED included: infant monitoring/abduction prevention; barcode identification; radiofrequency identification (RFID)- or infrared (IR)-based patient tracking. Twenty articles supported the use of tracking technology to enhance patient safety or improve efficiency. One article failed to support the use of IR patient sensors due to study design flaws. Conclusions: Support exists for the use of barcode-, IR-, and RFID-based patient tracking systems to improve ED patient safety and efficiency. A lack of methodologically strong studies indicates a need for further evidence-based support for the implementation of patient tracking technology in a clinical or research setting. [Copyright &y& Elsevier]
- Published
- 2013
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10. Sensor Selection for Activity Classification at Smart Home Environments.
- Author
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Bolleddula N, Chun Hung GY, Ma D, Noorian H, and Woodbridge DM
- Subjects
- Engineering, Privacy, Technology
- Abstract
As the world's older population grows dramatically, the needs of continuing care retirement communities increases. Studies show that privacy can be a major concern for adopting technologies, while the older population prefers smart homes [1]. In order to minimize the number of sensors to be installed in each house, we performed Principal Component Analysis (PCA) to filter out the relatively unimportant sensors. We applied a machine learning model to classify residents' activity types, using a different set of sensors chosen by PCA. Then, we validated the trade-off between the classification model accuracy and the number of sensors used in classification. Our experiment shows that feature engineering helps reduce accuracy degradation for activity type classification when using fewer sensors in smart homes.
- Published
- 2020
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11. Impact of an observation unit and an emergency department-admitted patient transfer mandate in decreasing overcrowding in a pediatric emergency department: a discrete event simulation exercise.
- Author
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Hung GR and Kissoon N
- Subjects
- British Columbia, Child, Hospital Units organization & administration, Humans, Patient Selection, Computer Simulation, Hospitalization statistics & numerical data, Hospitals, Pediatric organization & administration, Intensive Care Units, Pediatric organization & administration, Patient Admission statistics & numerical data, Patient Transfer organization & administration
- Abstract
Objectives: The primary objective was to examine the effects of a simulated observation unit (OU) and a transfer mandate for admitted patients on pediatric emergency department (PED) patient flow indicators. The secondary objective was to report on the occupancy rate of the simulated OU., Methods: Simulations were conducted using a previously designed and validated discrete event simulation model of our PED operations. A simulated OU was designed, and an emergency department-admitted patient transfer mandate was developed and then applied to a discrete event simulation model. Four scenarios (regular PED operations with and without a 5-bed OU and transfer mandate in all combinations) were modeled., Results: A combination of an OU and an emergency department-admitted patient transfer mandate resulted in reductions in time to be seen by a physician and length of stay in patients who were triaged with urgent or emergent presentations as compared with PED operations with neither an OU nor a transfer mandate. Small improvements in fractile response were observed for patients triaged with urgent presentations. The OU without the transfer mandate had a simulated occupancy rate of 73.1%. The inclusion of the transfer mandate reduced the occupancy rate to 48.1%., Conclusions: Simulation scenario analyses predict that an OU and a transfer mandate would reduce overcapacity in the PED, with more substantial reductions in time to be seen and length of stay for patients of high acuity.
- Published
- 2009
- Full Text
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12. A consensus-established set of important indicators of pediatric emergency department performance.
- Author
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Hung GR and Chalut D
- Subjects
- Adult, Benchmarking, Female, Guideline Adherence, Health Care Surveys, Hospitals, Pediatric, Humans, Male, Middle Aged, Ontario, Pediatrics standards, Pediatrics trends, Practice Patterns, Physicians' standards, Quality Assurance, Health Care, Sensitivity and Specificity, Surveys and Questionnaires, Emergency Service, Hospital standards, Employee Performance Appraisal standards, Practice Guidelines as Topic, Quality Indicators, Health Care standards
- Abstract
Background: Quality assurance is a new and important area of research in pediatric emergency medicine (PEM). There are few studies that describe which performance indicators best represent the PEM practice. The primary study objective is to construct a set of performance indicators that have been selected by current and former pediatric emergency department (PED) medical directors as most useful in assessing PED performance. The secondary objective is to assess which indicators are currently measured to assess performance in PEDs., Methods: Current and former directors of accredited Canadian PEM programs were considered as eligible participants. A list of indicators was generated by a survey (item pool generation); this list was refined by clarifying unclear terms or eliminating redundant and unquantifiable performance indicators (item scaling); PED directors were asked to rate each item of this refined list to indicate which indicators were more useful in assessing PED performance (item prioritization). A novel ranking formula was used to prioritize those items considered most useful by a larger proportion of respondents, using the provided rating scores., Results: Fourteen current and former medical directors were considered eligible participants. Indicators related to patient morbidity and mortality, adverse outcomes, return visits, patient length of stay (LOS), and waiting times were considered to be more useful. Less useful indicators included the number of deaths, daily census, number of incident reports, and individual physicians' admission rates. The most commonly measured PED performance indicators included the rate of patients who left without being seen, patient LOS, and the waiting time until being seen by a physician by triage category., Conclusions: The top quartile of performance indicators considered most useful by participants included indicators that reflected clinical outcomes, LOS, and waiting times. A dichotomy may exist between those performance indicators that PED directors considered more useful and those indicators that are currently measured.
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- 2008
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13. Principles of managing children with asthma in the emergency department.
- Author
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Hung GR
- Abstract
INTRODUCTION: Paediatric asthma exacerbations comprise a significant portion of emergency department (ED) visits and hospitalizations. Recognition of diagnostic symptoms and signs, and timely use of appropriate medications may reduce the need of hospitalizations and the impact of this disease on the lives of children and their families. OBJECTIVE: To review the pathophysiology of asthma, the current recommendations for conventional medical treatment in the ED, the controversies surrounding adjunct therapies, and the importance of discharge planning and follow-up. CONCLUSIONS: Paediatric asthma exacerbations may be successfully treated in the ED with the use of appropriate inhaled and systemic medications.
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- 2007
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14. Computer modeling of patient flow in a pediatric emergency department using discrete event simulation.
- Author
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Hung GR, Whitehouse SR, O'Neill C, Gray AP, and Kissoon N
- Subjects
- Appointments and Schedules, Efficiency, Organizational, Humans, Length of Stay statistics & numerical data, Personnel Staffing and Scheduling, Time and Motion Studies, Triage, Computer Simulation, Emergency Service, Hospital organization & administration, Hospitals, Pediatric organization & administration, Models, Organizational, Process Assessment, Health Care
- Abstract
Unlabelled: Increasing patient census and department overcrowding are universal concerns in pediatric emergency medicine. Accurate predictions of patient flow and resource utilization in the pediatric emergency department (PED) are important in determining what aspects of PED activity could be modified to improve patient flow, reduce patient waiting times, and increase staff efficiency and morale, and thus direct change more effectively., Background: We report (1) the construction of a Patient Flow Model (PFM) using discrete event simulation to test simulated PED staffing scenarios that were designed to alleviate the pressures that result from increased census and overcrowding, and (2) a Physician Scheduling Analysis Tool to assist in physician scheduling., Methods: Arena discrete event simulation modeling software was used to develop a model of PED patient flow after extensive interviews with PED staff and direct observation of patient flow in July 2005. A total of 517 patients were directly observed, and all modeled aspects of their interaction with PED staff and resources were recorded. Historical demographic patient arrival information was combined with observed patient flow data to provide simulated patient arrival rates for the PFM and was also used to construct the Physician Scheduling Analysis Tool. Validation of the PFM was performed by comparing annual simulated patient flow data with actual patient flow data. Previously determined staffing scenarios were applied to the simulation and the resulting performance indicator outputs examined., Results: The PFM was validated on model-wide and process-specific levels, with excellent validation observed on high acuity-patient length of stay and for highly detailed processes such as triage and registration. Simulation of the addition of a hospital volunteer and a second triage nurse demonstrated reductions in pretriage waiting time and the proportion of patients waiting longer than 30 or 60 minutes for pretriage. Simulation of an extra physician shift to the staff schedule demonstrated reductions in length of stay for patients of all triage categories., Conclusions: The PFM accurately represents patient flow through the department and can provide simulated patient flow information on a variety of scenarios. It can effectively simulate changes to the model and its effects on patient flow.
- Published
- 2007
- Full Text
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