With the growing adoption of laparoscopic surgery practices, high quality training and qualification of laparoscopic skills through objective assessment has become critical. While eye-gaze and instrument motion analyses have demonstrated promise in producing objective metrics for skill assessment in laparoscopic surgery, three areas deserve further research attention. First, most eye-gaze metrics do not account for trainee behaviors that change the visual scene or context that can be addressed by computer vision. Second, feedforward control metrics leveraging on the relationship between eye-gaze and hand movements has not been investigated in laparoscopic surgery. Finally, eye-gaze metrics have not demonstrated sensitivity to skill progressions of trainees as the literature has focused on differences between experts and novices although feedback on skill acquisition is most useful for trainees or educators. To advance eye-gaze assessment in laparoscopic surgery, this research presents a three-stage gaze based assessment methodology to provide a standardized process for generating context-dependent gaze metrics and estimating the proficiency levels of medical trainees on surgery. The three stages are: (1) contextual scene analysis for segmenting surgical scenes into areas of interest, (2) compute context dependent gaze metrics based on eye fixation on areas of interest, and (3) defining and estimating skill proficiency levels with unsupervised and supervised learning, respectively. This methodology was applied to analyze 499 practice trials by nine medical trainees practicing the peg transfer task in the Fundamental of Laparoscopic Surgery program. The application of this methodology generated five context dependent gaze and one tool movement metrics, defined three proficiency levels of the trainees, and developed a model predicting proficiency level of a participant for a given trial with 99% accuracy. Further, two of six metrics are completely novel, capturing feed-forward behaviors in the surgical domain. The results also demonstrated that gaze metrics could reveal skill levels more precisely than between experts and novices as suggested in the literature. Thus, the metrics derived from the gaze based assessment methodology also shows high sensitive to trainee skill levels. The implication of this research includes providing automated feedback to trainees on where they have looked during practice trial and what skill proficiency level attained after each practice trial. / Master of Science / Laparoscopic surgery is type of minimally invasive surgery which is being widely adopted. Skills required for performing laparoscopic surgeries are different than open surgeries. Hence, it is critical to ensure that adequate training and assessment is provided to surgeons. Eye-gaze tracking technology has made it possible to compute metrics that could be employed for skill assessment. These metrics are based on involuntary gaze behaviors and are independent of the nature of the surgical training task being performed. Hence, they may not be suitable for feedback during training. Metrics suitable for feedback are context dependent metrics which take into account the task based information. Experts tend to show look-ahead behavior while performing a task which can be quantified using context dependent metrics. This research presents a three stage methodology which facilitates computation of context dependent metrics and feed-forward metrics enabling identification of different skill levels in trainees. Applying this methodology to dataset of nine trainees with 499 practice trials, a total of six metrics were computed and a classification model was built to predict three identified skill level with 99% accuracy. This research is directly applicable to developing an automated system for laparoscopic training and assessment.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Uterine manipulation is integral to obtaining adequate access to the uterus during a laparoscopic procedure. A variety of mechanical manipulators have been developed to aid the surgeon with the dissection of the uterus during laparoscopic hysterectomies. Limitations of existing manipulators are that they require an additional assistant during surgery, are expensive and may cause tissue trauma to the vaginal or cervical canal. This study introduces the novel concept of a magnetic uterine manipulator, intended to overcome existing devices’ shortcomings and enabling non-invasive uterine manipulation. The first goal of the study was to investigate the strengths and weaknesses of existing mechanical manipulators and compare them to those of a magnetic device. Analysis showed that a magnetic manipulator would not be able to compete in terms of the range of motion of existing devices. A limited anteriorsagittal rotation range of 60 was seen in the magnetic manipulator compared to a range of 140 in mechanical devices. However, the magnetic manipulator could eliminate the need for an extra assistant, is reusable and thus also more economical. The second goal was to investigate which type of setup would be most successful at effective uterine manipulation. Through concept analysis a cart-on-arch system was deemed most effective. To lift an effective load of 1 N over an air-gap of 150 mm rare-earth N38 Neodymium (NdFeBr) magnets showed the most promise as magnetic actuators. FEA (Finite Element Analysis) simulations of the magnetic setup were validated experimentally which produced an acceptable MAE (mean absolute error) of 0.15 N. Furthermore, a comparative simulation study of shielded and unshielded magnets was done which concluded that shielded magnets produce a slightly higher attraction force and would be safer to use due to less magnetic flux fringing. Thirdly and lastly, potential safety hazards and risks of using magnetic actuators in surgical environments were identified. The literature research revealed that connections between magnetic fields and health risks to patients have not been conclusively proven in clinical studies to date, but nonetheless, great care should be taken in situations where the patient has a pace-maker or orthopaedic implants, as these might interact with the magnetic field. Recommendations for future work include further research into the geometry and scaling effects of magnetic shielding as well as electromagnetic actuator design. Electromagnetic actuators could replace rare-earth magnets, if coil and cooling systems are optimized, resulting in magnets that can be reversed or switched off and which are therefore easier to control and safer to handle. / AFRIKAANSE OPSOMMING: Ontwikkeling van ’n Magnetiese Intra-Uteriene Manipuleerder Baarmoedermanipulasie is van uiterste belang om sodoende voldoende toegang te kry tot die baarmoeder gedurende ’n laparoskopiese prosedure. Daar is reeds ’n verskeidenheid meganiese manipuleerders ontwikkel as hulpmiddel vir die chirurg in die ontleding van die uterus tydens laparoskopiese histerektomies. Beperkings van bestaande manipuleerders is dat ’n bykomende assistent tydens chirurgie benodig word. Die manipuleerders is ook duur en kan weefseltrauma veroorsaak aan die vaginale of servikale kanale. Die studie stel ’n nuwe konsep bekend: ’n magnetiese baarmoedermanipuleerder, gemik daarop om bestaande toestelle se tekortkominge te oorkom en nie-indringende baarmoedermanipulasie moontlik te maak. Die eerste doel van die studie was om die voordele en nadele van bestaande meganiese manipuleerders te ondersoek en dit te vergelyk met dié van die magnetiese toestel. Analise het getoon dat ’n magnetiese manipuleerder nie met bestaande toestelle sal kan kompeteer waar dit gaan om beweegruimte nie. Daar is ’n beperkte anterior-sagitale rotasiespeling van 60 in die magnetiese manipuleerder, terwyl die meganiese toestel ’n rotasiespeling van 140 het. Die magnetiese manipuleerder kan egter die nodigheid van ’n bykomende assistant uitskakel, is herbruikbaar en dus ook meer ekonomies. Die tweede doel van die studie was om die tipe opstelling wat meer suksesvol sal wees tydens doeltreffende baarmoeder manipulasie te ondersoek. Konsep-analise het getoon dat ’n "cart-on-arch"stelsel die beste sal werk. N38 Neodimium (NdFeBr) magnete het die beste vertoon as magnetiese aandrywer om ’n werklike belasting van 1 N oor ’n lugspasie van 150 mm te lig. EEA (Eindige Element Analise) simulasies van die magnetiese opstelling is eksperimenteel bekragtig en het ’n aanvaarbare gemene absolute fout (GAF) van 0.15 N gelewer. ’n Vergelykende simulasie studie het verder gewys dat beskutte magnete ’n effens hoër aantrekkingskrag oplewer en sal dus veiliger wees om te gebruik vanweë die verminderde magnetiese stromingsrand. Derdens en laastens is potensiële veiligheidsrisikos en gevare in die gebruik van magnetiese drywers in chirurgiese omgewings geïdentifiseer. Literatuurnavorsing het onthul dat die verband tussen magneetvelde en gesondheidsrisikos aan pasiënte nog nie voldoende bewys is in kliniese studies tot op datum nie. Gevalle waar pasiënte ’n pasaangeër of ortopediese inplantings het moet met groot sorg hanteer word aangesien dit dalk kan reageer met die magneetvelde. Aanbevelings vir toekomstige werk sluit verdere navorsing in in die rigting van die geometrie en die afskilferingseffek van magnetiese beskutting en ook elektromagnetiese drywer ontwerp. Elektromagnetiese drywers kan moontlik rou aarde magnete vervang indien winding en afkoelstelsels ge-optimeer word wat kan lei tot magnete wat omgekeer of afgeskakel kan word en dus makliker beheerbaar is en veiliger om te hanteer.

Cheung, Tak Hong. / "July 2011." / Thesis (M.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 166-199). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.

子宮切除術是最常進行的婦科手術之一，據統計，美國每年平均錄得約600,000宗進行子宮切除術的病例。全腹腔鏡子宮切除術為子宮切除術的一種，在手術中，病人的子宮將經由完全使用腹腔鏡的模式被摘除。 / 在普遍全腹腔鏡子宮切除術的流程中，名為舉宮器的手術儀器會被應用於手術中，以改變病人子宮的位置及方向。手術室內，除了負責為病人摘除子宮的醫生外，還需額外一名負責操作舉宮器的醫生在場，以促進手術的進行。於手術的過程中，為使摘除手術能更有效及順利地進行，這名醫生需以人手操作舉宮器以控制病人體內子宮的方位。一般而言，這項工作都是枯燥而疲憊的。然而，在負責進行摘除手術的醫生眼中，縱子宮的方位已被調整，其方位仍然未如理想的情況亦不屬罕見。 / 故此，一個能勝任代替醫生負責操作舉宮器的機械人助手將會是可行的解決方案之一。與此同時，機械人亦能將病人子宮方位的控制權交回負責進行摘除手術的醫生手中。 / 本論文提出一套以把醫生從操作舉宮器的工作中釋放為目標，並使子宮方位操作變得更準確及穩定的機械人系統。機械人系統由兩個部分構成，分別為一支一個自由度的電動舉宮器以及一台三個自由度的舉宮器方位操作機械人。 / 舉宮器方位操作機械人旨在模仿以往醫生操作舉宮器的動作，以負責把固定在它身上的舉宮器移動到及固定在指定的位置。舉宮器方位操作機械人共有三個關節，分別為旋轉關節、滑動關節以及線性關節。關節的佈置滿足特定的幾何約束以構成遠程運動中心，使機械人能把手術儀器從細小的開口（例如：子宮頸）中進行操作。本論文提出的舉宮器方位操作機械人備有配適器以兼容不同款式的舉宮器，例如市場上現存的舉宮器以及本論文提出的電動舉宮器，均可應用在本系統中。 / 本論文提出的電動舉宮器為系統中可選擇性的元件，它是個一自由度附帶可轉動末端的裝置，旨在延伸機械人系統末端執行器的可到達範圍。 / 本論文將論述這套機械人系統的設計，包括其機械設計與電子系統的部分、運動學與及工作空間。一台實驗用的樣機已被建造以作驗證設計之用。該樣機以醫學人體模型為對象的實驗結果亦會在本論文中提出。 / Hysterectomy is one of the most frequently performed gynecologic procedures. In average, around 600,000 cases are recorded annually in the United States. Total laparoscopic hysterectomy (TLH) is one of the approaches of performing hysterectomy in which uterus of a patient is removed from an entirely laparoscopic approach. / In ordinary TLH procedures, a surgical apparatus, uterus manipulator, used for changing the position and orientation of the patient’s uterus is involved. In the operating theatre, apart from the primary surgeon who is responsible for the removal of uterus, an assisting surgeon is also involved for operating the uterus manipulator. Throughout the surgery, she/he has to manipulate the patient’s uterus using the uterus manipulator manually to facilitate the removal procedure. This task is generally tiring and boring. In addition, it is also common that the manipulated position is not satisfactory from the primary surgeon’s point of view. / Thus, a robotic assistant which is capable of taking up the task of this assisting surgeon as well as allowing the primary surgeon to have full control on the position of the patient’s uterus may be one of the potential solutions. / In this thesis, a robotic system aiming at providing more precise and stable manipulating motion and freeing the assisting surgeon who is responsible for operating the uterus manipulator is presented. The presented robotic system is composed of two parts, a motorized uterus manipulator of one degree of freedom and a robotic uterus manipulator positioner of three degrees of freedom. / Objective of the uterus manipulator positioner presented is to imitate what is doing by the assisting surgeon when operating the uterus manipulator. It holds and manipulates the uterus manipulator attached to it. The uterus manipulator positioner is a robotic system consisted of three joints, a revolute joint, a sliding joint and a translational joint. Arrangement of the joints is forced to satisfy specific geometric constraints so that a remote center of motion (RCM) is created to allow manipulation through small openings such as the cervix. Adaptors are included to enable the use of different uterus manipulators. Existing uterus manipulators and the motorized uterus manipulator presented in this thesis can be adapted to the system. / The motorized uterus manipulator presented in this thesis is an optional element of the robotic system. It is a device of one degree of freedom with a movable tip aiming at enhancing the reaching capability of the end-effector of the robotic system. / In this thesis, design of the robotic system in both mechanical and electronic aspects is presented. Kinematics and workspace of the system is also discussed. To verify the design, a prototype is built. Finally, verification experiments with the prototype on manikin are provided. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yip, Hiu Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 96-98). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Abstract --- p.i / 摘要 --- p.iv / Acknowledgement --- p.vi / Table of Contents --- p.viii / List of Figures --- p.x / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Total Laparoscopic Hysterectomy --- p.1 / Chapter 1.2. --- Existing Uterus Manipulators --- p.4 / Chapter 1.3. --- Existing Uterus Manipulator Positioners --- p.6 / Chapter 1.4. --- Existing Medical Robots --- p.9 / Chapter 1.5. --- Existing RCM Mechanisms --- p.11 / Chapter 1.6. --- Motivation and Contribution --- p.12 / Chapter Chapter 2. --- Conceptual Design --- p.15 / Chapter 2.1. --- Design Requirements --- p.15 / Chapter 2.2. --- Conceptual Design of Prototype --- p.16 / Chapter Chapter 3. --- Design of Prototype --- p.23 / Chapter 3.1. --- Mechanical Design of the Robotic System --- p.25 / Chapter 3.1.1. --- Design of the Robotic Uterus Manipulator Positioner --- p.25 / Chapter 3.1.2. --- Adaptor --- p.35 / Chapter 3.1.3. --- Design of the Motorized Uterus Manipulator --- p.36 / Chapter 3.2. --- Kinematics of the Robotic System --- p.38 / Chapter 3.2.1. --- Coordinates of Points on a Sphere --- p.39 / Chapter 3.2.2. --- The 2-DOF Uterus Manipulator Positioner --- p.40 / Chapter 3.2.3. --- The 3-DOF Uterus Manipulator Positioner --- p.42 / Chapter 3.2.4. --- The 4-DOF robotic system --- p.45 / Chapter 3.2.5. --- Velocity --- p.50 / Chapter Chapter 4. --- Design of Control System --- p.52 / Chapter 4.1. --- Robot Controlling Unit --- p.52 / Chapter 4.1.1. --- Size Reduced Controlling Unit --- p.53 / Chapter 4.2. --- User Interface --- p.62 / Chapter 4.2.1. --- Foot-Controlled Interface --- p.63 / Chapter 4.2.2. --- Hand-Controlled Panel --- p.68 / Chapter Chapter 5. --- Prototype and Experiments --- p.70 / Chapter 5.1. --- Developed Prototype --- p.70 / Chapter 5.2. --- Experiments --- p.72 / Chapter 5.2.1. --- Robot Controller --- p.73 / Chapter 5.2.2. --- Control Algorithm --- p.77 / Chapter 5.2.3. --- Experiment on the Prototype --- p.79 / Chapter 5.2.4. --- Experiment with Manikin --- p.87 / Chapter Chapter 6. --- Conclusion and Future Work --- p.90 / Chapter 6.1. --- Conclusion --- p.90 / Chapter 6.2. --- Robot Positioning Platform --- p.92 / Chapter 6.3. --- Reinforcement of the Robotic System --- p.94 / Chapter 6.4. --- Extension of User Interfaces --- p.95 / List of References --- p.96

This study was an investigation into the cost-effectiveness of using re-usable instrumentation in laparoscopic surgery. The model used for the study was the laparoscopic cholecystectomy which is the commonest laparoscopic procedure performed by the general surgeons. The study was done at KZNGOV Hospital in Kwazulu Natal, one of the largest tertiary hospitals in the province. The research done was both qualitative and quantitative. An exploratory study was conducted initially by drawing up the case study, and then quantitative and qualitative research was conducted to evaluate the use of re-usable instrumentation in laparoscopic surgery. In order to conduct a more focused design, the three most commonly used laparoscopic instruments were evaluated. These were the trocars (sizes 11.0mm and 5.0mm), the endoshears / scissors and the clip applicators. The study aimed to assess whether the use of the re-usable instruments was more cost-effective, whether their use in minimal access surgery was feasible, and whether the use of re-usable instrumentation compromised patient well-being. Information for the case study was obtained from the hospital notes of the patients who had a laparoscopic cholecystectomy at KZNGOV Hospital, and from interviews with experienced surgeons. The study found that the re-usable instrumentation used at KZNGOV Hospital had no adverse effects on the patients. The Department of Surgery and the theatre committee at this hospital have chosen an excellent and cost-effective protocol for laparoscopic surgery, and the choice of instrumentation cannot be faulted. Analysis of the results showed a large cost saving obtained by using the re-usable laparoscopic instrumentation, with no adverse patient outcomes. / Thesis (MBA)-University of KwaZulu-Natal, Durban, 2003.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Embora alguns estudos tenham descrito as semelhanças e diferenças anatômicas entre o rim humano e o rim suíno, pouco é conhecido sobre a cicatrização renal neste animal. O conhecimento da cicatrização do rim do porco é especialmente importante em procedimentos cirúrgicos que incisem o tecido renal e o sistema coletor, como é o caso da nefrectomia parcial. O objetivo do presente trabalho é estudar a cicatrização renal em porcos após nefrectomia parcial laparoscópica sem o fechamento do sistema coletor. Quatorze porcos machos com peso médio de 30 Kg foram submetidos à nefrectomia parcial laparoscópica esquerda, removendo 25 % do comprimento renal no pólo caudal (n = 7) ou no pólo cranial (n = 7). A técnica cirúrgica empregada envolveu acesso laparoscópico transperitoneal, clampeamento em bloco dos vasos renais, excisão do tecido renal com tesoura a frio e aplicação de energia monopolar para hemostasia do parênquima, deixando o sistema coletor aberto. Os animais foram avaliados clinicamente por 14 dias e então foram mortos. Níveis séricos de creatinina e uréia foram obtidos antes e em diferentes momentos após a cirurgia. São relatados ainda os achados de necropsia, pielografia retrógrada ex vivo e aspectos histológicos dos pólos renais operados. Os níveis séricos de uréia e creatinina tiveram leve aumento inicial retornando aos valores pré-operatórios durante o período avaliado. Durante a necropsia verificou-se que não houve extravasamento de urina a partir do rim operado e que este se cobriu com tecido fibroso, aderindo-se aos tecidos adjacentes. Nas pielografias retrógradas não foi verificado nenhum extravasamento de contraste pelos pólos operados. Os achados histológicos mostraram grande deposição de colágeno tipo I sobre o pólo renal operado, vedando-o completamente. O rim suíno não é um bom modelo para pesquisas ou treinamento cirúrgico em que a cicatrização do sistema coletor seja um aspecto importante. / Although some studies have described similarities and differences between human and pig kidney anatomy, little is known regarding renal healing in this animal model. The knowledge of pig kidney healing is especially important in surgical procedures which incise the renal parenchyma and collecting system, such as partial nephrectomy. The aim of this study is to access kidney healing in pigs after laparoscopic partial nephrectomy without closuring of the collecting system. Fourteen male pigs with mean weight of 30 kg were submitted to left partial laparoscopic nephrectomy, removing 25% of the kidney length at caudal pole (n = 7) or at cranial pole (n = 7). Briefly, the surgical technique involved a transperitoneal laparoscopic access, en bloc vascular clamping of renal artery and vein, tissue excision with cold scissor and monopolar energy parenchyma hemostasis, leaving the collecting system opened. The animals were clinically evaluated during fourteen days, and afterwards were killed. Serum levels of creatinine and urea were assessed prior and at different moments after surgery. Necropsy findings, retrograde ex vivo pyelogram and histological aspects of operated renal poles are also described. Serum creatinine and urea showed a slight initial increase with a gradual return to preoperative levels during the evaluated period. At necropsy, no signs of urine leakage were found and kidneys were covered by a fibrous tissue with adherences to adjacent organs. Also, in the retrograde pyelograms obtained, we did not find contrast medium leakage by operated poles. Histological findings showed great deposition of type I collagen over operated renal pole, sealing it completely. The pig kidney is not an adequate experimental model for research and training of surgery on which collecting system healing is an important aspect to be considered.

The research presented in this thesis represents a body of work which addresses issues in medical imaging, primarily as it applies to breast cancer screening and laparoscopic surgery. The concern here is how computer based methods can aid medical practitioners in these tasks. Thus, research is presented which develops both new techniques of analysing radiologists performance data and also new approaches of examining surgeons visual behaviour when they are undertaking laparoscopic training. Initially a new chest X-Ray self-assessment application is described which has been developed to assess and improve radiologists performance in detecting lung cancer. Then, in breast cancer screening, a method of identifying potential poor performance outliers at an early stage in a national self-assessment scheme is demonstrated. Additionally, a method is presented to optimize whether a radiologist, in using this scheme, has correctly localised and identified an abnormality or made an error. One issue in appropriately measuring radiological performance in breast screening is that both the size of clinical monitors used and the difficulty in linking the medical image to the observer s line of sight hinders suitable eye tracking. Consequently, a new method is presented which links these two items. Laparoscopic surgeons have similar issues to radiologists in interpreting a medical display but with the added complications of hand-eye co-ordination. Work is presented which examines whether visual search feedback of surgeons operations can be useful training aids.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Embora alguns estudos tenham descrito as semelhanças e diferenças anatômicas entre o rim humano e o rim suíno, pouco é conhecido sobre a cicatrização renal neste animal. O conhecimento da cicatrização do rim do porco é especialmente importante em procedimentos cirúrgicos que incisem o tecido renal e o sistema coletor, como é o caso da nefrectomia parcial. O objetivo do presente trabalho é estudar a cicatrização renal em porcos após nefrectomia parcial laparoscópica sem o fechamento do sistema coletor. Quatorze porcos machos com peso médio de 30 Kg foram submetidos à nefrectomia parcial laparoscópica esquerda, removendo 25 % do comprimento renal no pólo caudal (n = 7) ou no pólo cranial (n = 7). A técnica cirúrgica empregada envolveu acesso laparoscópico transperitoneal, clampeamento em bloco dos vasos renais, excisão do tecido renal com tesoura a frio e aplicação de energia monopolar para hemostasia do parênquima, deixando o sistema coletor aberto. Os animais foram avaliados clinicamente por 14 dias e então foram mortos. Níveis séricos de creatinina e uréia foram obtidos antes e em diferentes momentos após a cirurgia. São relatados ainda os achados de necropsia, pielografia retrógrada ex vivo e aspectos histológicos dos pólos renais operados. Os níveis séricos de uréia e creatinina tiveram leve aumento inicial retornando aos valores pré-operatórios durante o período avaliado. Durante a necropsia verificou-se que não houve extravasamento de urina a partir do rim operado e que este se cobriu com tecido fibroso, aderindo-se aos tecidos adjacentes. Nas pielografias retrógradas não foi verificado nenhum extravasamento de contraste pelos pólos operados. Os achados histológicos mostraram grande deposição de colágeno tipo I sobre o pólo renal operado, vedando-o completamente. O rim suíno não é um bom modelo para pesquisas ou treinamento cirúrgico em que a cicatrização do sistema coletor seja um aspecto importante. / Although some studies have described similarities and differences between human and pig kidney anatomy, little is known regarding renal healing in this animal model. The knowledge of pig kidney healing is especially important in surgical procedures which incise the renal parenchyma and collecting system, such as partial nephrectomy. The aim of this study is to access kidney healing in pigs after laparoscopic partial nephrectomy without closuring of the collecting system. Fourteen male pigs with mean weight of 30 kg were submitted to left partial laparoscopic nephrectomy, removing 25% of the kidney length at caudal pole (n = 7) or at cranial pole (n = 7). Briefly, the surgical technique involved a transperitoneal laparoscopic access, en bloc vascular clamping of renal artery and vein, tissue excision with cold scissor and monopolar energy parenchyma hemostasis, leaving the collecting system opened. The animals were clinically evaluated during fourteen days, and afterwards were killed. Serum levels of creatinine and urea were assessed prior and at different moments after surgery. Necropsy findings, retrograde ex vivo pyelogram and histological aspects of operated renal poles are also described. Serum creatinine and urea showed a slight initial increase with a gradual return to preoperative levels during the evaluated period. At necropsy, no signs of urine leakage were found and kidneys were covered by a fibrous tissue with adherences to adjacent organs. Also, in the retrograde pyelograms obtained, we did not find contrast medium leakage by operated poles. Histological findings showed great deposition of type I collagen over operated renal pole, sealing it completely. The pig kidney is not an adequate experimental model for research and training of surgery on which collecting system healing is an important aspect to be considered.

La chirurgie laparoscopique conventionnelle apporte des avantages aux patients mais pose des défis aux chirurgiens. Utiliser le robot permet de surmonter certaines des difficultés. Nous utilisons ici le concept de comanipulation, où un bras robotique sert de comanipulateur et génère des champs de force pour aider les chirurgiens. Pour implémenter des fonctions telles que la compensation de la gravité de l’instrument, il est utile de connaître la position du trocart en temps réel par rapport à la base du robot. Nous proposons un algorithme de détection et localisation de trocarts, basé sur la méthode du moins carré. Des expériences in vitro et in vivo valident son efficacité. Considérant des caractéristiques de la chirurgie laparoscopique, i.e., de l’espace de travail grand et de la difficulté de planifier le geste, des champs visqueux sont utilisés. Afin de s’adapter aux mouvements différents, nous utilisons une loi de commande de viscosité variable. Cependant, elle rencontre un problème d’instabilité, qui est analysé théoriquement et expérimentalement. Une solution d’ajout d’un filtre passe-bas de premier ordre est proposée, dont l’efficacité est mise en évidence par une expérience de ciblage point à point. Avec la position du trocart connue, nous pouvons établir «le modèle de levier», une formule décrivant la relation entre les vitesses et les forces appliquées à différents points de l’instrument. Ceci permet de mettre en œuvre une loi de commande de viscosité sans utiliser de signaux bruités, au point de centre de la poignée ou la pointe de l’instrument. Une expérience est menée pour comparer l’influence de la loi de commande sur les comportements de mouvement humain. / Traditional laparoscopic surgery brings advantages to patients but poses challenges to surgeons. The introduction of robots into surgical procedures overcomes some of the difficulties. In this work, we use the concept of comanipulation, where a 7-joint serial robotic arm serves as a comanipulator and generates force fields to assist surgeons.In order to implement functions like instrument gravity compensation, identifying real-time trocar position with respect to robot base is a prerequisite. Instead of obtaining trocar information from the registration step, we propose a robust trocar detection and localization algorithm based on least square method. Both in-vitro and in-vivo experiments validate its efficiency.Considering the characteristics of laparoscopic surgery, i.e., relatively large workspace and flexible operating objects, viscous fields are employed. To better adapt to different motion, we use a variable viscosity controller. However, this controller encounters an instability problem, which is analyzed both theoretically and experimentally. A solution of adding a first order low pass filter is proposed to slow down the variation of the viscosity coefficient, whose efficiency is evidenced by a point-to-point targeting experiment.With real-time trocar position known, the “lever model”, a formula describing therelationship of the velocities and forces of different instrument points, can be established. This allows implementing viscosity controller without using noisy signals at the center points of instrument handle and tip. Another point-to-point movement experiment is conducted to compare the features of the controller influence on human motion behaviors.

The aim of this study was to compare two ovariectomy techniques (conventional vs laparoscopic) in bitches planning determine which procedure offers the lowest hemodynamic changes, painful stimuli, stress and inflammatory changes in trans and post-operative period. For the experiment were used 17 young mongrel bitches (12,58 ± 4,29 months), weighting 10.16 ± 0,69kg. Animals were placed into two groups according to the technique applied. In the first group (eight animals), ovariectomy (OV) was done by retro-umbilical celiotomy (GC) and in the second group (nine animals), by laparoscopy two-portal access (GV). For the assessment of analgesia were measured hemodynamic parameters (heart rate, respiratory rate, systolic arterial pressure, medium arterial pressure, diastolic arterial pressure, central venous pressure and cardiac output), and used three pain scales as follows: visual analogue (VAS), the University of Melbourne and the scale consists of Glasgow. To evaluate the stress and inflammatory changes were evaluated different parameters (C-reactive protein, cortisol, protein electrophoresis and acetylcholinesterase determination). In both procedures (GV and GC) there were no trans or post-operative complications. This study found that two-portal laparoscopic ovariectomy provides smaller and shorter pain stimuli that conventional ovariectomy when considering the following times and pain scales (two hours after surgery in Melbourne and the scale of 12 and 24 hours postoperative VAS), as well as in assessing the methods used to analyze the inflammatory response and stress, laparoscopic technique provided a lower elevation and a more rapid decline in the levels of C-reactive protein, mainly from six up to 72 hours after surgery, that the conventional technique. / O objetivo deste estudo foi comparar duas técnicas de ovariectomia (convencional vs laparoscópica) em cadelas, buscando determinar qual procedimento oferece menores alterações hemodinâmicas, estímulos dolorosos, estresse e alterações inflamatórias nos períodos trans e pós-operatório. Para o experimento foram utilizadas 17 cadelas jovens (12,58 ± 4,29 meses), sem raça definida, com peso médio de 10,16 ± 0,69kg. Os animais foram alocados em dois grupos, de acordo com a técnica operatória aplicada. No primeiro grupo (oito animais), a ovariectomia (OV) foi efetuada por celiotomia retro-umbilical (GC) e, no segundo grupo (nove animais), pela técnica de videolaparoscopia por dois portais (GV). Para a avaliação hemodinâmica foram aferidos parâmetros FC, , PAS, PAM, PAD, pressão venosa central e débito cardíaco e, para a avaliação álgica, foram empregadas três escalas de dor: visual analógica (EVA), da universidade de Melbourne, e a composta de Glasgow. Para avaliação do estresse e das alterações inflamatórias, foram avaliados diferentes parâmetros: cortisol, proteína C reativa, eletroforese de proteínas e acetilcolinesterase. Em ambos procedimentos (GV e GC) não ocorreram complicações trans ou pós-operatórias. Concluiu-se que a técnica de ovariectomia videolaparoscópica por dois portais propiciou estímulo álgico de menores magnitude e duração que a ovariectomia convencional ao se considerar os seguintes tempos e escalas de dor (duas horas de pós-operatório na escala de Melbourne e nas 12 e 24 horas de pós-operatório na EVA). Ademais, a técnica videolaparoscópica propiciou menor elevação e declínio mais rápido nos níveis séricos de proteína C reativa, sobretudo a partir de seis até 72 horas de pós-operatório, em relação à técnica convencional.