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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development and validation of a virtual environment as a training tool for surgeons in knee arthroscopy

McCarthy, Avril Dawn January 2000 (has links)
No description available.
2

Quantitative modelling and assessment of surgical motor actions in minimally invasive surgery

Cristancho, Sayra Magnolia 05 1900 (has links)
The goal of this research was to establish a methodology for quantifying performance of surgeons and distinguishing skill levels during live surgeries. We integrated three physical measures (kinematics, time and movement transitions) into a modeling technique for quantifying performance of surgical trainees. We first defined a new hierarchical representation called Motor and Cognitive Modeling Diagram for laparoscopic procedures, which: (1) decomposes ‘tasks’ into ‘subtasks’ and at the very detailed level into individual movements ‘actions’; and (2) includes an explicit cognitive/motor diagrammatic representation that enables to take account of the operative variability as most intraoperative assessments are conducted at the ‘whole procedure’ level and do not distinguish between performance of trivial and complicated aspects of the procedure. Then, at each level of surgical complexity, we implemented specific mathematical techniques for providing a quantitative sense of how far a performance is located from a reference level: (1) The Kolgomorov-Smirnov statistic to describe the similarity between two empirical cumulative distribution functions (e.g., speed profiles) (2) The symmetric normalized Jensen-Shannon Divergence to compare transition probability matrices (3) The Principal Component Analysis to identify the directions of greatest variability in a multidimensional space and to reduce the dimensionality of the data using a weight space. Two experimental studies were completed in order to show feasibility of our proposed assessment methodology by monitoring movements of surgical tools while: (1) dissecting mandarin oranges, and (2) performing laparoscopic cholecystectomy procedures at the operating room to compare residents and expert surgeons when executing two surgical tasks: exposing Calot’s Triangle and dissecting the cystic duct and artery. Results demonstrated the ability of our methodology to represent selected tasks using the Motor and Cognitive Modeling Diagram and to differentiate skill levels. We aim to use our approach in future studies to establish correspondences between specific surgical tasks and the corresponding simulations of these tasks, which may ultimately enable us to do validated assessments in a simulated setting, and to test its reliability in differentiating skill levels at the operating room as the number of subjects and procedures increase.
3

Quantitative modelling and assessment of surgical motor actions in minimally invasive surgery

Cristancho, Sayra Magnolia 05 1900 (has links)
The goal of this research was to establish a methodology for quantifying performance of surgeons and distinguishing skill levels during live surgeries. We integrated three physical measures (kinematics, time and movement transitions) into a modeling technique for quantifying performance of surgical trainees. We first defined a new hierarchical representation called Motor and Cognitive Modeling Diagram for laparoscopic procedures, which: (1) decomposes ‘tasks’ into ‘subtasks’ and at the very detailed level into individual movements ‘actions’; and (2) includes an explicit cognitive/motor diagrammatic representation that enables to take account of the operative variability as most intraoperative assessments are conducted at the ‘whole procedure’ level and do not distinguish between performance of trivial and complicated aspects of the procedure. Then, at each level of surgical complexity, we implemented specific mathematical techniques for providing a quantitative sense of how far a performance is located from a reference level: (1) The Kolgomorov-Smirnov statistic to describe the similarity between two empirical cumulative distribution functions (e.g., speed profiles) (2) The symmetric normalized Jensen-Shannon Divergence to compare transition probability matrices (3) The Principal Component Analysis to identify the directions of greatest variability in a multidimensional space and to reduce the dimensionality of the data using a weight space. Two experimental studies were completed in order to show feasibility of our proposed assessment methodology by monitoring movements of surgical tools while: (1) dissecting mandarin oranges, and (2) performing laparoscopic cholecystectomy procedures at the operating room to compare residents and expert surgeons when executing two surgical tasks: exposing Calot’s Triangle and dissecting the cystic duct and artery. Results demonstrated the ability of our methodology to represent selected tasks using the Motor and Cognitive Modeling Diagram and to differentiate skill levels. We aim to use our approach in future studies to establish correspondences between specific surgical tasks and the corresponding simulations of these tasks, which may ultimately enable us to do validated assessments in a simulated setting, and to test its reliability in differentiating skill levels at the operating room as the number of subjects and procedures increase.
4

Quantitative modelling and assessment of surgical motor actions in minimally invasive surgery

Cristancho, Sayra Magnolia 05 1900 (has links)
The goal of this research was to establish a methodology for quantifying performance of surgeons and distinguishing skill levels during live surgeries. We integrated three physical measures (kinematics, time and movement transitions) into a modeling technique for quantifying performance of surgical trainees. We first defined a new hierarchical representation called Motor and Cognitive Modeling Diagram for laparoscopic procedures, which: (1) decomposes ‘tasks’ into ‘subtasks’ and at the very detailed level into individual movements ‘actions’; and (2) includes an explicit cognitive/motor diagrammatic representation that enables to take account of the operative variability as most intraoperative assessments are conducted at the ‘whole procedure’ level and do not distinguish between performance of trivial and complicated aspects of the procedure. Then, at each level of surgical complexity, we implemented specific mathematical techniques for providing a quantitative sense of how far a performance is located from a reference level: (1) The Kolgomorov-Smirnov statistic to describe the similarity between two empirical cumulative distribution functions (e.g., speed profiles) (2) The symmetric normalized Jensen-Shannon Divergence to compare transition probability matrices (3) The Principal Component Analysis to identify the directions of greatest variability in a multidimensional space and to reduce the dimensionality of the data using a weight space. Two experimental studies were completed in order to show feasibility of our proposed assessment methodology by monitoring movements of surgical tools while: (1) dissecting mandarin oranges, and (2) performing laparoscopic cholecystectomy procedures at the operating room to compare residents and expert surgeons when executing two surgical tasks: exposing Calot’s Triangle and dissecting the cystic duct and artery. Results demonstrated the ability of our methodology to represent selected tasks using the Motor and Cognitive Modeling Diagram and to differentiate skill levels. We aim to use our approach in future studies to establish correspondences between specific surgical tasks and the corresponding simulations of these tasks, which may ultimately enable us to do validated assessments in a simulated setting, and to test its reliability in differentiating skill levels at the operating room as the number of subjects and procedures increase. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
5

On the Use of Simulation and Assessment in Surgical Training

Wagner, Natalie January 2019 (has links)
The transition from medical school to residency is often considered the most difficult year for both teachers and learners. Learners report feeling underprepared, and some researchers have identified a decrease in patient safety during the first month of residency. These factors suggest learners could be better supported during this transition period. Previous research demonstrates that boot camps (BCs) at the onset of residency can improve learners’ confidence, knowledge, and some technical skills. However, little information has been published on how those BCs were developed and implemented, why BCs only improve some skills and not others, or the long-term impacts of BC programs. We used a Context, Input, Process, and Product program evaluation framework to develop, implement, and evaluate a simulation-based BC for novice surgical trainees that was aligned with the recent shift towards competency-based models of medical education. Next, we used a Convergent Parallel Mixed Methods approach to explore the longer-term impacts of the BC program. Lastly, we explored how effectively the Objective Structured Clinical Examination (OSCE), a “gold standard” measure of learner competence that was used in the BC program, truly captures clinical performance of novice trainees. This work demonstrates that incorporating a BC at the onset of residency can improve residents’ confidence and skill for up to two years into training, although adherence to sound pedagogical principles is critical. The BC also provided residents with the opportunity to participate in role clarification, acculturation, and social integration. Finally, we demonstrate that OSCEs may not always be the best way to measure BC effectiveness. The data presented in this thesis will provide educators with new insights on how to create and evaluate successful BC programs to support learners through the transition to residency; highlight new approaches for evaluating educational initiatives; and prompt a conversation about how assessment is being used in medical education. / Dissertation / Doctor of Philosophy (PhD) / From day one, new doctors are expected to adapt to new training environments, manage increased workloads, and make decisions about patient care, while working longer hours, and with less support than they had as medical students. As such, research suggests that new doctors often feel underprepared and stressed when entering residency. Furthermore, the ‘July Effect’, which suggests that fatal medical errors rise by 10% in the first month of residency compared with all other months, suggests that something needs to change. In this thesis, we sought to improve the way that surgical training programs approach the transition into residency, and look at the long-term impacts of these changes. Through three interrelated studies, we provide educators with information on how to develop, implement, and evaluate a simulation-based boot camp for new doctors; highlight new approaches for evaluating educational initiatives; and revisit how assessment is being used in medical education.
6

MR IMAGE OVERLAY: AN AUGMENTED REALITY SYSTEM FOR NEEDLE GUIDANCE

U-Thainual, Paweena 02 October 2013 (has links)
MRI-guided percutaneous needle-based surgery has become part of routine clinical practice. There are millions of these procedures performed in Canada. The conventional MRI-guided needle intervention is usually performed with the primary goal of navigating a needle to a target while sparing healthy and/or critical structures. Potential limitations of conventional unassisted free-hand needle placement include the physician's ability to align and maintain the correct trajectory and angle toward a target, especially in case of deep targets. In contemporary practice, images are displayed on the operator's 2D console only outside the treatment room, where the physician plans the intervention. Then the physician enters the room, mentally registers the images with the anatomy of the actual patient, and uses hand-eye coordination to execute the planned intervention. Previous concept has been shown and preliminary results discussed from demonstrated MRI-guided needle intervention using an augmented reality 2D image overlay system in a closed configuration 1.5T MRI scanner. However, the limited availability of interventional MR imaging systems and the length of time of MR-guided interventions have been limiting factors in the past. This dissertation addresses topics related to evaluating and developing the 2D augmented reality system, the assistance device for MRI-guided needle interventions. This research effort has primarily focused on developing a new adjustable 2D MR image overlay system and validating the previous 2D image overlay system in the clinical environment. The adjustable system requirement is to overcome the oblique insertions, difficulties inherent to MR-guided procedures, and to promise safe and reliable needle placement inside closed high-field MRI scanners. This thesis describes development of the image overlay system including requirements, mechanism design and evaluation of MR compatibility. Additionally, a standalone realization of an MR image overlay system, named “The Perk Station” was developed, implemented and evaluated. The system was deployed in the laboratory as a training/teaching tool with non-bio-hazardous specimens. This laboratory version of the system allows for evaluation of trial interventions. The system also supports recording of the complete intervention trajectory for operator performance, technical efficacy, and accuracy studies of insertion techniques. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2013-09-30 22:21:51.469
7

Desenvolvimento e avaliação de método substitutivo para a prática da hemostasia em cadáveres quimicamente preservados / Development and evaluation of a substitute method for hemostasis practice in chemically preserved cadavers

Souza, Maria Claudia de Campos Mello Inglez de 23 November 2012 (has links)
O aprendizado e o ensino da cirurgia veterinária envolvem o desenvolvimento de habilidades que podem ser obtidas em laboratórios, por meio de vários modelos já disponíveis, incluindo o treinamento em cadáveres. Nestes, quando comparados aos procedimentos em animais vivos, duas limitações são notadas e frequentemente mencionadas, e referem-se às alterações de consistência dos tecidos e à ausência de sangramento durante o treinamento cirúrgico. Este trabalho foi focado na superação destas questões, por meio da realização da simulação de circulação sanguínea em cadáveres adequadamente preservados, permitindo aos usuários do sistema a possibilidade de treinamento cirúrgico em um modelo mais próximo do animal vivo, viabilizando também o aprendizado e a prática da hemostasia. Depois de desenvolvido o sistema, o mesmo foi utilizado por estudantes de Medicina Veterinária com distintos níveis de experiência, que avaliaram todo o método por meio de questionário, ressaltando também os pontos positivos e negativos observados. Concluiu-se que é possível realizar a simulação de sangramento em cadáveres quimicamente preservados, e que tal sistema foi bem aceito por quem o utilizou, sendo mais uma alternativa para melhor preparar estudantes para as experiências em animais vivos que necessitem de intervenções cirúrgicas. / Veterinary surgery demands skills acquisition and refinement that can be obtained in laboratories using several available models, including training on cadavers. Those, when compared to live animal procedures, two limitations are noted and often mentioned, and are due to tissue consistency alterations and absence of bleeding during surgical training. This work was focused on overcoming these issues, by performing blood flow simulation in properly chemically preserved cadavers, giving users of this system the possibility of surgical training in a model closer to live animal, also enabling learning and practice of hemostasis. After developed the system, it was used by veterinary students with distinct experience levels, evaluating the whole method through a questionnaire, emphasizing positive and negative aspects. It was concluded that bleeding simulation in chemically preserved cadavers is possible, and that such a system was well accepted by those who used it, being an alternative to better prepare students for experiments on live animals that require surgical interventions.
8

The Effects of a Multi-View Camera System on Spatial Cognition, Cognitive Workload and Performance in a Minimally Invasive Surgery Task

January 2019 (has links)
abstract: Minimally invasive surgery is a surgical technique that is known for its reduced patient recovery time. It is a surgical procedure done by using long reached tools and an endoscopic camera to operate on the body though small incisions made near the point of operation while viewing the live camera feed on a nearby display screen. Multiple camera views are used in various industries such as surveillance and professional gaming to allow users a spatial awareness advantage as to what is happening in the 3D space that is presented to them on 2D displays. The concept has not effectively broken into the medical industry yet. This thesis tests a multi-view camera system in which three cameras are inserted into a laparoscopic surgical training box along with two surgical instruments, to determine the system impact on spatial cognition, perceived cognitive workload, and the overall time needed to complete the task, compared to one camera viewing the traditional set up. The task is a non-medical task and is one of five typically used to train surgeons’ motor skills when initially learning minimally invasive surgical procedures. The task is a peg transfer and will be conducted by 30 people who are randomly assigned to one of two conditions; one display and three displays. The results indicated that when three displays were present the overall time initially using them to complete a task was slower; the task was perceived to be completed more easily and with less strain; and participants had a slightly higher performance rate. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2019
9

Desenvolvimento e avaliação de método substitutivo para a prática da hemostasia em cadáveres quimicamente preservados / Development and evaluation of a substitute method for hemostasis practice in chemically preserved cadavers

Maria Claudia de Campos Mello Inglez de Souza 23 November 2012 (has links)
O aprendizado e o ensino da cirurgia veterinária envolvem o desenvolvimento de habilidades que podem ser obtidas em laboratórios, por meio de vários modelos já disponíveis, incluindo o treinamento em cadáveres. Nestes, quando comparados aos procedimentos em animais vivos, duas limitações são notadas e frequentemente mencionadas, e referem-se às alterações de consistência dos tecidos e à ausência de sangramento durante o treinamento cirúrgico. Este trabalho foi focado na superação destas questões, por meio da realização da simulação de circulação sanguínea em cadáveres adequadamente preservados, permitindo aos usuários do sistema a possibilidade de treinamento cirúrgico em um modelo mais próximo do animal vivo, viabilizando também o aprendizado e a prática da hemostasia. Depois de desenvolvido o sistema, o mesmo foi utilizado por estudantes de Medicina Veterinária com distintos níveis de experiência, que avaliaram todo o método por meio de questionário, ressaltando também os pontos positivos e negativos observados. Concluiu-se que é possível realizar a simulação de sangramento em cadáveres quimicamente preservados, e que tal sistema foi bem aceito por quem o utilizou, sendo mais uma alternativa para melhor preparar estudantes para as experiências em animais vivos que necessitem de intervenções cirúrgicas. / Veterinary surgery demands skills acquisition and refinement that can be obtained in laboratories using several available models, including training on cadavers. Those, when compared to live animal procedures, two limitations are noted and often mentioned, and are due to tissue consistency alterations and absence of bleeding during surgical training. This work was focused on overcoming these issues, by performing blood flow simulation in properly chemically preserved cadavers, giving users of this system the possibility of surgical training in a model closer to live animal, also enabling learning and practice of hemostasis. After developed the system, it was used by veterinary students with distinct experience levels, evaluating the whole method through a questionnaire, emphasizing positive and negative aspects. It was concluded that bleeding simulation in chemically preserved cadavers is possible, and that such a system was well accepted by those who used it, being an alternative to better prepare students for experiments on live animals that require surgical interventions.
10

A design tool for use in simulation and training of sinus surgery

Taylor, Richard E. January 2010 (has links)
The traditional approaches to training surgeons are becoming increasingly difficult to apply to modern surgical procedures. The development of Minimally Invasive Surgery (MIS) techniques demands new and complex psychomotor skills, and means that the apprentice-based system described by 'see one, do one, teach one' can no longer be expected to fully prepare surgeons for operations on real patients, placing patient safety at risk. The use of cadavers and animals in surgical training raises issues of ethics, cost and anatomical similarity to live humans. Endoscopic sinus surgery involves further risk to the patient due to the proximity of vital structures such as the brain, eyes, optic nerve and internal carotid artery. In recent years, simulation has been used to overcome these problems, exposing surgeons to complex procedures in a safe environment, similarly to its use in aviation. However, the cases simulated in this manner may not be customised by training staff to present desired pathology. This thesis describes the design and development of a new tool for the creation of customised cases for the training of sinus surgery. Users who are inexperienced and non-skilled in the use of three-dimensional (3D) Computer Aided Design (CAD) modelling software may use the tool to implement pathology to the virtual sinus model, which was constructed from real CT data. Swelling is applied in five directions (four horizontal, one vertical) to the cavity lining of the frontal and sphenoid sinuses. Tumours are individually customised and positioned in the frontal, sphenoid and ethmoid sinuses. The customised CAD model may then be latterly manufactured using Three-Dimensional Printing (3DP) to produce the complex anatomy of the sinuses in a full colour physical part for the realistic simulation of surgical procedures. An investigation into the colouring of the physical model is also described, involving the study of endoscopic videos to ascertain realistic shades. The program was evaluated by a group of medical professionals from a range of fields, and their feedback was taken into account in subsequent redevelopment of the program, and to suggest further work.

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