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 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13029号 / 論医博第2111号 / 新制||医||1016(附属図書館) / 32987 / (主査)教授 大森 孝一, 教授 別所 和久, 教授 坂井 義治 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Virtual reality (VR) for surgical training shows promise in preparing surgeons for complex procedures. However, achieving a high level of realism in VR is essential for the skills acquired to translate effectively into real-world applications. One challenge is the underestimation of perceived depth in VR compared to the real world, which can significantly impact applications requiring precise depth perception. This study aims to investigate how object shape influences depth perception in VR, as it may contribute to the observed underestimation of distances. Specifically, the research focuses on minimally invasive neurosurgery (MIS), where surgeons operate through small incisions on the skull without direct visualization of the inside of the skull. Training in a highly accurate VR simulation could offer a safe practice environment for surgeons. Previous studies have explored the use of VR for training in various fields, including medicine, transport, and military applications. However, concerns exist regarding whether VR accurately represents real-life scenarios, particularly with regard to depth perception. Research indicates that participants often underestimate egocentric distances in VR, which can pose challenges in MIS procedures where precise targeting is crucial. This study builds upon previous research conducted by KTH master’s students in 2022, which examined spatio-temporal distance perception in VR. This study expands on this work by investigating the influence of object shape on depth perception. Previous research has shown that different object shapes, luminance, and colors can impact depth perception in VR. Understanding how object shape affects depth perception can contribute to improving the realism of VR simulations for surgical training, particularly for MIS procedures. / Virtual Reality (VR) i utbildningssyfte inom kirurgi visar lovande resultat för att utbilda kirurger inför komplexa ingrepp. Dock är det viktigt att uppnå en hög grad av realism i VR för att de förvärvade färdigheterna ska kunna överföras till verkliga tillämpningar. En utmaning är att tidigare studier visat på att VR har en negativ inverkan på djupseendet, vilket kan ha en betydande påverkan på tillämpningar som kräver exakt djupseende. Denna studie syftar till att undersöka hur ett objekts form påverkar djupseendet i VR. Specifikt fokuserar vår studie på minimalinvasiv hjärnkirurgi (MIS), där kirurger utför ingrepp genom små snitt som görs i skallen med begränsad insyn. Träning i en VR-simulering kan erbjuda en säker övningsmiljö för kirurger. Tidigare studier har utforskat användningen av VR för träning inom olika områden, inklusive medicin, transport och militära tillämpningar. Dock finns det en oro för huruvida VR korrekt återger verkliga scenarion, särskilt med avseende på djupseendet. Forskning indikerar att deltagare ofta underskattar egocentriska avstånd i VR, vilket kan utgöra en utmaning för MIS-ingrepp där små avstånd är avgörande. Denna studie bygger på tidigare forskning utförd av masterstudenter vid KTH 2022, vilken undersökte uppfattningen av rumtid i VR. Denna studie bygger vidare på denna forskning genom att undersöka hur objektets form påverkar djupseendet. Tidigare forskning har visat att olika objektformer, ljusstyrkor och färger kan påverka djupseendet i VR. Att förstå hur objektets form påverkar djupseendet kan bidra till att förbättra realismen i VR-simuleringar för kirurgisk träning, särskilt för MIS-ingrepp.

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

<p>Root phenotyping technology is an essential component of modern agriculture and plant science research. Conducting root-related research in a non-destructive manner is crucial for studying plant roots without damaging the plants themselves and allowing for time-series studies. The research aims to validate the efficacy of MISIRoot, an innovative root phenotyping technology, through the implementation of two projects. The first project focuses on the early detection of western corn rootworm, one of the most devastating corn rootworm species in North America, particularly in midwestern corn-growing areas. The second project focuses on the assessment of the soybean nodulation process, which is crucial for nitrogen fixation by Rhizobia living in the nodules on the soybean roots. The current state-of-the-art methods for western corn rootworm and soybean nodulation assessments still require the whole plant to be dug up, which causes irreversible destruction to the plant itself. Although recently developed root phenotyping methods such as minirhizotron, CT, and MRI scanners offer unique advantages in observing plant roots, their potential for field applications is currently limited.</p> <p>Data collection for both projects was carried out using MISIRoot, a minimally invasive plant root phenotyping robot that works in situ within natural soil. The MISIRoot system mainly consists of an industrial-level robotic arm, a mini-size camera with a lighting set, a plant pot holding platform, and image processing software for root recognition and feature extraction. MISIRoot can take high-resolution color images of the roots in soil with minimal disturbance to the root and reconstruct the plant roots' three-dimensional (3D) structure at an accuracy of 0.1 mm.</p> <p>For the first project, the MISIRoot system successfully distinguished the corn plants inoculated with western corn rootworm larvae from the healthy plants before the shoot section of the corn plants revealed significant differences. For the second project, the MISIRoot system successfully demonstrated its ability to differentiate soybean plants with and without nodules.</p>

Complete or partial obstruction of the duodenum by the superior mesenteric artery (SMA) is a rare cause of bowel obstruction. SMA syndrome results from the compression of the 3rd part of the duodenum between the superior mesenteric artery and the abdominal aorta. Causes include anatomical variation in the superior mesenteric artery, trauma, burns, surgeries, malignancy, and rapid weight loss. Diagnosis of SMA syndrome in patients may be difficult, as the clinical findings often resemble other forms of small bowel obstructions. This syndrome was first described in the literature by Carl Freiherr von Rokitansky in 1861. Subsequently, David Wilke provided a comprehensive description of the disease in a series of 75 patients. There has been skepticism about the existence of SMA syndrome due to scant literature reports and non-specific symptomatology. However, modern cross-sectional imaging has confirmed the existence of this rare syndrome. Here we present the case of a 50-year-old female with longstanding symptoms of gastrointestinal discomfort, weight loss, nausea, and vomiting. She underwent an exhaustive gastrointestinal workup until a diagnosis of SMA syndrome was made. We elected to proceed with a minimally invasive three-port laparoscopic, trans-mesenteric side-to-side duodenojejunostomy. The patient was discharged on postoperative day one after tolerating a regular diet. On one month follow-up, our patient reported improvement in symptoms with no postprandial pain or nausea and normal bowel movements. In conclusion, we report a case of superior mesenteric artery syndrome in a patient with recurrent abdominal pain and nausea. CT scan has the highest sensitivity for the diagnosis of SMA syndrome, findings suggestive of the diagnosis include an abnormal aortomesenteric angle and distance. While supplemental tube feeds and gastric drainage may resolve the condition without the need for surgery, this often takes many weeks to months to be effective. Minimally invasive surgical bypass is an attractive option because of the rapidity of symptom resolution, lack of need for long-term invasive tubes, short inpatient length of stay, and high success rate.

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.

Background: Pediatric minimally invasive surgery (MIS) is a standard technique worldwide. We aimed to analyze the research activity in this field. Methods: Articles on pediatric MIS (1991–2020) were analyzed from the Web of Science™ for the total number of publications, citations, journals, and impact factors (IF). Of these, the 50 most cited publications were evaluated in detail and classified according to the level of evidence (i.e., study design) and topic (i.e., surgical procedure). Results: In total, 4464 publications and 53,111 citations from 684 journals on pediatric MIS were identified. The 50 most cited papers were published from 32 institutions in the USA/Canada (n = 28), Europe (n = 19), and Asia (n = 3) in 12 journals. Four authors (USA/Europe) contributed to 26% of the 50 most cited papers as first/senior author. Hot topics were laparoscopic pyeloplasty (n = 9), inguinal hernia repair (n = 7), appendectomy, and pyloromyotomy (n = 4 each). The majority of publications were retrospective studies (n = 33) and case reports (n = 6) (IF 5.2 ± 3.2; impact index 16.5 ± 6.4; citations 125 ± 39.4). They were cited as often as articles with high evidence levels (meta-analyses, n = 2; randomized controlled trials, n = 7; prospective studies, n = 2) (IF 12.9 ± 22.5; impact index 14.0 ± 6.5; citations 125 ± 34.7; p > 0.05). Conclusions: Publications on laparoscopic pyeloplasty, inguinal hernia repair, appendectomy, and pyloromyotomy are cited most often in pediatric MIS. However, the relevant number of studies with strong evidence for the advantages of MIS in pediatric surgery is missing.