Estão disponíveis para treinamento videocirúrgico métodos in vitro e treino em animais, antes de se estar apto para chegar ao paciente propriamente dito. O treino em animais vivos tem sua importância no fato de mimetizar situações reais, permitindo o treinamento, não só da técnica, mas também de conduta e trabalho em equipe. Em contrapartida, o uso de animais vivos utilizados em treinamento cirúrgico (vivissecção) e pesquisa têm encontrado oposição em questões éticas e de bem estar animal. A utilização de cadáveres para o treinamento e desenvolvimento de novas técnicas cirúrgicas em Medicina tem se tornado uma alternativa interessante para a videocirurgia. No presente estudo foram testados como modelos experimentais cadáveres de cães conservados com a solução de Larssen modificada, que mantém as características teciduais do cadáver semelhantes às de um cão vivo. Foram utilizados 10 cães oriundos da rotina do Hospital de Clínicas Veterinárias da Universidade Federal do Rio Grande do Sul ou do Centro de Controle de Zoonoses de Porto Alegre, com indicação de eutanásia por patologias graves e sem tratamento. Após a eutanásia, foram preparados com solução de Larssen modificada, a fim de manterem características teciduais semelhantes as de um cão vivo, sendo armazenados em freezer após o preparo. Estes cadáveres, depois de descongelados, foram testados quanto a viabilidade do modelo para treinamento de nefrectomia total laparoscópica e tireoidectomia videoendoscópica. Foram avaliadas no transoperatório, características teciduais como: coloração, textura e odor dos cadáveres e também, a pressão de dióxido de carbono utilizada para a insuflação. O modelo experimental em cadáveres de cães conservados com solução de Larssen modificada foi viável e efetivo para treinamento em videocirurgia nas técnicas propostas; embora alguns cães, durante a nefrectomia laparoscópica evidenciassem os rins friáveis. No que se refere às características teciduais avaliadas, foram semelhantes às de um animal vivo, e a pressão média de dióxido de carbono utilizada durante a nefrectomia total laparoscópica foi de 15,58 mmHg e para a tireoidectomia videoendoscópica foi de 15,75 mmHg. / In consideration of the fact that training with live animals simulates real situations, it has still its importance. It allows not only technical training but also conduct and teamwork. In contrast, the use of live animals in surgical training (vivisection) and research has found opposition due to ethical and animal welfare concerns. The use of cadavers for training and development of new surgical techniques in medicine has become an interesting alternative for videosurgery. In the present study cadavers of dogs, conserved with a modified Larssen solution were used as experimental models. This modified Larssen solution preserves the tissue of the body with similar characteristics to the tissue of alive dogs. Ten dogs from the routine of the Veterinary Hospital of the Federal University of Rio Grande do Sul and the Porto Alegre's Zoonosis Control Center with indication of euthanasia for serious diseases were used for this study. After euthanasia the dogs were prepared with the modified Larssen solution and were stored in freezers. Before beginning procedures the cadaveres were defrosted, the bodies of the dogs were tested to evaluate the training feasibility for laparoscopic total nefrectomy and videoendoscopic thyroidectomy. In the next step characteristics like coloration, tissue structure, odor and pressure of carbon dioxide for inflation has been evaluated. The experimental model to prepare dog cadavers with modified Larssen solution proved to be practicable and effective for training in videosurgery within the proposed procedures. Even though, some dogs showed friable kidneys during laparoscopic nephrectomy. In relation to the evaluated tissue characteristics, the experimental model showed similar characteristics of a living animal. The middle pressure of carbon dioxide was 15,58 mmHg during laparoscopic total nefrectomy and 15,75 mmHg during videoendoscopic thyroidectomy.

Simulação computacional de ambientes cirúrgicos têm sido amplamente utilizados, normalmente para treinamentos, ajudando no desenvolvimento de habilidades essenciais e minimizando erros em procedimentos cirúrgicos. Para estes ambientes, é essencial a obtenção de um comportamento mais realista, sendo importante o uso de técnicas com alta precisão, além de uma simulação em tempo real. A fim de melhor controlar este trade-off entre eficiência e eficácia, apresentamos um ambiente híbrido e adaptativo que combina um conjunto de métodos para alcançar uma boa precisão e desempenho na simulação. Nosso sistema mescla métodos físicos de deformação (Método de Elementos Finitos e Mass-Mola) com um método não-físico que aproxima o comportamento dos primeiros (Green Coordinates), sendo capaz de utilizar o método apropriado dependendo da situação. Para melhor simular um ambiente cirúrgico completo, foram implementadas ferramentas adicionais para interação, permitindo pegar e manipular, queimar, e sentir os objetos do cenário. Nosso sistema proporciona grande imersão ao usuário, consumindo menos recursos computacionais e aumentando as taxas de atualização da simulação. / Computational simulation of surgical environments have been widely used usually for trainings, improving essential skills and minimizing errors in surgical procedures. As these environments are always looking for a more realistic behavior, it is important to use high-precision techniques while ensuring a real-time simulation. In order to better manage this trade-off between efficiency and effectiveness, we present a hybrid and adaptive environment that combines a set of methods to achieve good accuracy and performance for a simulation. Our system merges physically deformation methods (Finite Elements Method and Mass Spring Damper) with a non-physical method that approximates the formers behavior (Green Coordinates), being able to use the appropriate method depending on the situation. To simulate an approximation of a complete surgical environment, we also implement interaction tools, such as picking, burning, and haptic feedback. Our system provides great immersion for the user, consuming less computational resources and increasing update rates.

abstract: Surgery as a profession requires significant training to improve both clinical decision making and psychomotor proficiency. In the medical knowledge domain, tools have been developed, validated, and accepted for evaluation of surgeons' competencies. However, assessment of the psychomotor skills still relies on the Halstedian model of apprenticeship, wherein surgeons are observed during residency for judgment of their skills. Although the value of this method of skills assessment cannot be ignored, novel methodologies of objective skills assessment need to be designed, developed, and evaluated that augment the traditional approach. Several sensor-based systems have been developed to measure a user's skill quantitatively, but use of sensors could interfere with skill execution and thus limit the potential for evaluating real-life surgery. However, having a method to judge skills automatically in real-life conditions should be the ultimate goal, since only with such features that a system would be widely adopted. This research proposes a novel video-based approach for observing surgeons' hand and surgical tool movements in minimally invasive surgical training exercises as well as during laparoscopic surgery. Because our system does not require surgeons to wear special sensors, it has the distinct advantage over alternatives of offering skills assessment in both learning and real-life environments. The system automatically detects major skill-measuring features from surgical task videos using a computing system composed of a series of computer vision algorithms and provides on-screen real-time performance feedback for more efficient skill learning. Finally, the machine-learning approach is used to develop an observer-independent composite scoring model through objective and quantitative measurement of surgical skills. To increase effectiveness and usability of the developed system, it is integrated with a cloud-based tool, which automatically assesses surgical videos upload to the cloud. / Dissertation/Thesis / Ph.D. Biomedical Informatics 2013

Simulação computacional de ambientes cirúrgicos têm sido amplamente utilizados, normalmente para treinamentos, ajudando no desenvolvimento de habilidades essenciais e minimizando erros em procedimentos cirúrgicos. Para estes ambientes, é essencial a obtenção de um comportamento mais realista, sendo importante o uso de técnicas com alta precisão, além de uma simulação em tempo real. A fim de melhor controlar este trade-off entre eficiência e eficácia, apresentamos um ambiente híbrido e adaptativo que combina um conjunto de métodos para alcançar uma boa precisão e desempenho na simulação. Nosso sistema mescla métodos físicos de deformação (Método de Elementos Finitos e Mass-Mola) com um método não-físico que aproxima o comportamento dos primeiros (Green Coordinates), sendo capaz de utilizar o método apropriado dependendo da situação. Para melhor simular um ambiente cirúrgico completo, foram implementadas ferramentas adicionais para interação, permitindo pegar e manipular, queimar, e sentir os objetos do cenário. Nosso sistema proporciona grande imersão ao usuário, consumindo menos recursos computacionais e aumentando as taxas de atualização da simulação. / Computational simulation of surgical environments have been widely used usually for trainings, improving essential skills and minimizing errors in surgical procedures. As these environments are always looking for a more realistic behavior, it is important to use high-precision techniques while ensuring a real-time simulation. In order to better manage this trade-off between efficiency and effectiveness, we present a hybrid and adaptive environment that combines a set of methods to achieve good accuracy and performance for a simulation. Our system merges physically deformation methods (Finite Elements Method and Mass Spring Damper) with a non-physical method that approximates the formers behavior (Green Coordinates), being able to use the appropriate method depending on the situation. To simulate an approximation of a complete surgical environment, we also implement interaction tools, such as picking, burning, and haptic feedback. Our system provides great immersion for the user, consuming less computational resources and increasing update rates.

Estão disponíveis para treinamento videocirúrgico métodos in vitro e treino em animais, antes de se estar apto para chegar ao paciente propriamente dito. O treino em animais vivos tem sua importância no fato de mimetizar situações reais, permitindo o treinamento, não só da técnica, mas também de conduta e trabalho em equipe. Em contrapartida, o uso de animais vivos utilizados em treinamento cirúrgico (vivissecção) e pesquisa têm encontrado oposição em questões éticas e de bem estar animal. A utilização de cadáveres para o treinamento e desenvolvimento de novas técnicas cirúrgicas em Medicina tem se tornado uma alternativa interessante para a videocirurgia. No presente estudo foram testados como modelos experimentais cadáveres de cães conservados com a solução de Larssen modificada, que mantém as características teciduais do cadáver semelhantes às de um cão vivo. Foram utilizados 10 cães oriundos da rotina do Hospital de Clínicas Veterinárias da Universidade Federal do Rio Grande do Sul ou do Centro de Controle de Zoonoses de Porto Alegre, com indicação de eutanásia por patologias graves e sem tratamento. Após a eutanásia, foram preparados com solução de Larssen modificada, a fim de manterem características teciduais semelhantes as de um cão vivo, sendo armazenados em freezer após o preparo. Estes cadáveres, depois de descongelados, foram testados quanto a viabilidade do modelo para treinamento de nefrectomia total laparoscópica e tireoidectomia videoendoscópica. Foram avaliadas no transoperatório, características teciduais como: coloração, textura e odor dos cadáveres e também, a pressão de dióxido de carbono utilizada para a insuflação. O modelo experimental em cadáveres de cães conservados com solução de Larssen modificada foi viável e efetivo para treinamento em videocirurgia nas técnicas propostas; embora alguns cães, durante a nefrectomia laparoscópica evidenciassem os rins friáveis. No que se refere às características teciduais avaliadas, foram semelhantes às de um animal vivo, e a pressão média de dióxido de carbono utilizada durante a nefrectomia total laparoscópica foi de 15,58 mmHg e para a tireoidectomia videoendoscópica foi de 15,75 mmHg. / In consideration of the fact that training with live animals simulates real situations, it has still its importance. It allows not only technical training but also conduct and teamwork. In contrast, the use of live animals in surgical training (vivisection) and research has found opposition due to ethical and animal welfare concerns. The use of cadavers for training and development of new surgical techniques in medicine has become an interesting alternative for videosurgery. In the present study cadavers of dogs, conserved with a modified Larssen solution were used as experimental models. This modified Larssen solution preserves the tissue of the body with similar characteristics to the tissue of alive dogs. Ten dogs from the routine of the Veterinary Hospital of the Federal University of Rio Grande do Sul and the Porto Alegre's Zoonosis Control Center with indication of euthanasia for serious diseases were used for this study. After euthanasia the dogs were prepared with the modified Larssen solution and were stored in freezers. Before beginning procedures the cadaveres were defrosted, the bodies of the dogs were tested to evaluate the training feasibility for laparoscopic total nefrectomy and videoendoscopic thyroidectomy. In the next step characteristics like coloration, tissue structure, odor and pressure of carbon dioxide for inflation has been evaluated. The experimental model to prepare dog cadavers with modified Larssen solution proved to be practicable and effective for training in videosurgery within the proposed procedures. Even though, some dogs showed friable kidneys during laparoscopic nephrectomy. In relation to the evaluated tissue characteristics, the experimental model showed similar characteristics of a living animal. The middle pressure of carbon dioxide was 15,58 mmHg during laparoscopic total nefrectomy and 15,75 mmHg during videoendoscopic thyroidectomy.

A técnica de videolaparoscopia exploratória da cavidade abdominal utilizada atualmente em equinos implica em uma série de dificuldades. Há necessidade do acesso cirúrgico bilateral da cavidade abdominal ou anestesia geral para acesso ventral com a finalidade de obter uma avaliação adequada das vísceras e, consequentemente, um diagnóstico mais preciso. Esse procedimento prolonga o tempo e aumenta os riscos de complicações transoperatórias e pós-cirúrgicas. Apesar de ser uma técnica bem estabelecida com situações em que as vantagens de sua utilização são evidentes, alguns fatores ainda limitam sua difusão, entre eles podemos destacar: o custo do equipamento que limita a utilização fora de Universidades, Centros de Pesquisas ou clínicas particulares especializadas em cirurgias veterinárias. Com o objetivo de minimizar os aspectos negativos dessa técnica e viabilizar seu uso na rotina clínica e cirúrgica de equinos, surgiu a ideia de buscar uma nova via de acesso à cavidade abdominal e utilizando o videocolonoscópio, equipamento de menor custo. No presente estudo, foi analisado o uso do endoscópio flexível na exploração abdominal de equinos machos castrados e fêmeas pelo acesso perianal. A técnica foi avaliada quanto à viabilidade de permitir ou não o acesso à cavidade e identificação das vísceras abdominais em equinos. Além disso, buscou-se verificar se o endoscópio flexível permite a obtenção de amostras de tecido hepático para avaliação histológica. Os animais foram, alimentados, desverminados e avaliados diariamente por meio de exame clínico geral durante o período do experimento. Colheitas de amostras de sangue para hemograma e dosagem de fibrinogênio foram realizadas antes e após o procedimento cirurgico para posterior analise. Todos os cuidados de rotina em relação à antissepsia cirúrgica foram devidamente tomados e os animais submetidos a protocolo de sedação e analgesia. Os procedimentos de pós-operatório como terapia analgésica, anti-inflamatória, inspeção e higienização diária do local de incisão foram prestados. O procedimento cirúrgico teve início com incisão na região perianal laterodorsal direita entre o ânus e o musculo semimembranoso utilizando bisturi e tesoura, seguida de divulsão romba com o dedo ao longo da parede retal até alcançar uma profundidade aproximada de 10 cm, momento no qual foi introduzida cânula metálica com 56 cm de comprimento e 16 mm de diâmetro (Ø). Por meio desta cânula foi introduzido o endoscópio flexível (videocolonoscópio), sendo o restante da introdução da cânula acompanhada por visualização indireta em monitor. A cânula foi forçada lentamente até atingir a cavidade peritoneal, momento a partir do qual foi realizada exploração da cavidade abdominal. As vísceras observadas foram anotadas em ficha especialmente desenvolvida para esta finalidade. Como parte da avaliação hepática foi realizada biópsia e o material obtido analisado no setor de patologia da Faculdade de Veterinária da UFRGS. Após dez dias de pós-operatório, quando em plenas condições de saúde, os equinos receberam alta. Os resultados permitem inferir que, o uso do endoscópio flexível na identificação das vísceras abdominais por meio de laparoscopia perianal é viável na rotina clínica e cirúrgica de equinos e possibilita obter amostras teciduais para avaliação histológica. No entanto, o emprego da técnica exige o treinamento da equipe cirúrgica, principalmente do cirurgião, bom planejamento e um diagnóstico pré-operatório incompleto que necessite complementação diagnóstica. / The technique of exploratory laparoscopy abdominal cavity used currently in horses involves a series of difficulties. There is need for bilateral abdominal cavity surgical access or general anesthesia for ventral access for the purpose of obtaining an adequate assessment of the viscera and, consequently, a more accurate diagnosis. This procedure extends and increases the risks of post-surgical complications and transoperatórias. Despite being a well-established technique in situations where the advantages of its use are evident, some factors still limit its spread, some of them are: the cost of equipment that limits the use out of universities, research centers or private clinics specialized in veterinary surgeries. In order to minimize the negative aspects of this technique and enable its use in routine clinical and surgical equine, the idea of seeking a new route to the abdominal cavity and using videocolonoscópio, lower equipment cost. In the present study, we analyzed the use of the flexible endoscope in the abdominal exploration equine barrows and gilts for access perianal. The technique was evaluated on the feasibility of allowing or not the access cavity and identification of the abdominal viscera in horses. In addition, sought to verify that the flexible endoscope allows obtaining liver tissue samples for histological evaluation. The animals were fed, wormed and evaluated daily by a general clinical examination during the period of the experiment. Sampling of blood for blood count and fibrinogen were measured before and after the surgical procedure for subsequent analysis. All routine care in relation to surgical antisepsis were duly taken and animals undergoing sedation and analgesia protocol. Procedures as postoperative analgesic therapy, anti-inflammatory, inspection and cleaning daily incision site were provided. The procedure began with surgical incision in the right laterodorsal perianal region between the anus and the semimembranosus muscle using a scalpel and scissors, then blunt dilatation of the finger along the rectal wall until it reaches an approximate depth of 10 cm, at which the metal cannula with 56 cm length and 16 mm in diameter (Ø) was introduced. Through this cannula was inserted flexible endoscope (videocolonoscópio), the remainder of the introduction of the cannula followed by indirect viewing monitor. The cannula was forced slowly to the peritoneal cavity, the time from which it was held exploration of the abdominal cavity. The cannula was forced slowly to the peritoneal cavity, the time from which it was held exploration of the abdominal cavity. The viscera were observed in annotated form specially developed for this purpose. As part of the evaluation of the liver, biopsy was performed and the obtained material analyzed at the pathology of the Veterinary School of UFRGS. After ten days postoperatively, when in full health, horses were discharged. The results allow us to conclude that the use of the flexible endoscope in the identification of abdominal viscera through perianal laparoscopy is feasible in routine clinical and surgical equine and enables to obtain tissue samples for histologic evaluation. However, the use of the technique requires training of the surgical team, especially the surgeon, good planning and a preoperative diagnosis requiring incomplete diagnostic workup.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23084号 / 医博第4711号 / 新制||医||1049(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 木村 剛, 教授 森本 尚樹, 教授 山下 潤 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Minimally invasive spine surgery (MISS) has proven to be advantageous over traditional open surgery as it minimizes the likelihood of tissue damage and infections. During MISS, surgeons create small incisions to allow access to the surgery site, however, opting for smaller incisions decreases the surgeon’s field of vision. To compensate, surgeons rely on preoperative and intraoperative ionizing imaging technologies for guidance. Conventional localization of the spine, registration of digital images to the patient during surgery, depends heavily on the surgeon’s anatomical knowledge and their experience. Preoperative images are typically created using 3D technology while intraoperative images use 2D technology. While the integration of preoperative 3D images and intraoperative 2D images can provide valuable assistance, patient’s preoperative and intraoperative positions do not coincide leading to additional use of ionizing imaging. The objective of this research was to propose a workflow that assists with image registration for MISS. The main component of the workflow was the creation of a script that automatically generates patient-specific digital guides, which will then be manufactured, to align the patient’s intraoperative and preoperative body position. By aligning the patient’s positions, the 3D printed surgical guide serves as a shared feature between the preoperative digital image and the actual patient. This allows for the intraoperative image to be registered to the preoperative image more accurately. Additionally, the guide acts as an attachment site for any additional instrument guides/supports. The surgical guide generating script utilizes the skin contour of patient’s torso region, extracted from medical images, to automatically produce the guide’s horizontal and vertical components. Adjustments are made to the components using CAD software before proceeding to manufacturing, via 3D printing, and assembly of the guide. To validate the workflow, more specifically the script’s ability to automatically generate surgical guides that fit over the patient’s back, a guide was created for a mannequin. The maximum gap between the mannequin and the horizontal components was 0.8 cm and 1.5 cm for the vertical component.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24799号 / 医博第4991号 / 新制||医||1066(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 石見 拓, 教授 川口 義弥 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Minimally invasive surgery (MIS) has several advantages over traditional methods. Scaling MIS instruments to smaller sizes and increasing their performance will enable surgeons to offer new procedures to a wider range of patients. In this work, two compliant mechanism-based minimally invasive surgical instrument wrist or gripper mechanisms are designed and analyzed.The cylindrical cross-axis flexural pivot (CCAFP) is a single-degree-of-freedom wrist mechanism that could be combined with existing gripper mechanisms to create a multi-degree-of freedom instrument. The simplicity of the CCAFP mechanism facilitates analysis and implementation. The flexures of the CCAFP are integral with the instrument shaft, enabling accessories to be passed through the lumen. The CCAFP is analyzed and determined to be a viable wrist mechanism for MIS instruments based on research results. A finite element (FE) model of the mechanism is created to analyze the force-deflection and strain-deflection relationships. Experimental results are used to verify the FE model. A 3 mm design is created that could undergo an angular deflection of +/- 90 degrees. The addition of cam surfaces to help guide the flexures and limit the maximum stress during deflection is explored. These cam surfaces can be integral to the instrument shaft along with the flexures. A 2 degree-of-freedom (DoF) CCAFP with intersecting axes of rotation is also introduced. The inverted L-Arm gripper compliant mechanism has 2 DoF, one wrist and one gripping. Three challenges associated with using compliant mechanisms in MIS instruments are considered: inadequate performance in compression, large flexure deformations, and a highly variable mechanical advantage. These challenges were resolved in the L-Arm design by inverting the flexures, tailoring flexure geometry and employing nitinol, and integrating pulleys into each jaw of the mechanism. The L-Arm was prototyped at several sizes to demonstrate functionality and scalability. A finite element model of the L-Arm flexure was created to determine the strain-deflection relationship. A fatigue test was completed to characterize nitinol for use in compliant mechanism MIS instruments.These concepts demonstrate the ability of compliant mechanisms to overcome the design and manufacturing challenges associated with MIS instruments at the 3 mm scale. The models and principles included in this work could be used in the application of compliant mechanisms to design new MIS instruments as well as in other areas that employ compliant mechanisms in a cylindrical form factor.