The persistence of the sciatic artery

The persistent sciatic artery (PSA) is a rare anatomical variant where the internal iliac artery and the axial artery of the embryo provide the major supply of the lower limb, the superficial femoral artery being usually poorly developed or absent. We describe an extremely large right PSA in a 79-year-old male cadaver during a medical gross anatomy course, with simultaneous existence of a hypoplastic superficial and deep femoral artery. The PSA, which was a continuation of the anterior division of the right internal iliac artery, entered the buttock through the greater sciatic foramen situated in the gluteal region laterally to the sciatic nerve and in the mid thigh medially to the same nerve, becoming in the popliteal fossa the popliteal artery. Neither the superficial nor the deep femoral artery had communication with the popliteal artery. Because the PSA in our study was the only blood supply to the lower limb, we present the embryologic origins and the clinical anatomy of this artery

Collaborative Gaze Channelling for Improved Cooperation During Robotic Assisted Surgery

The use of multiple robots for performing complex tasks is becoming a common practice for many robot applications. When different operators are involved, effective cooperation with anticipated manoeuvres is important for seamless, synergistic control of all the end-effectors. In this paper, the concept of Collaborative Gaze Channelling (CGC) is presented for improved control of surgical robots for a shared task. Through eye tracking, the fixations of each operator are monitored and presented in a shared surgical workspace. CGC permits remote or physically separated collaborators to share their intention by visualising the eye gaze of their counterparts, and thus recovers, to a certain extent, the information of mutual intent that we rely upon in a vis-à-vis working setting. In this study, the efficiency of surgical manipulation with and without CGC for controlling a pair of bimanual surgical robots is evaluated by analysing the level of coordination of two independent operators. Fitts' law is used to compare the quality of movement with or without CGC. A total of 40 subjects have been recruited for this study and the results show that the proposed CGC framework exhibits significant improvement (p<0.05) on all the motion indices used for quality assessment. This study demonstrates that visual guidance is an implicit yet effective way of communication during collaborative tasks for robotic surgery. Detailed experimental validation results demonstrate the potential clinical value of the proposed CGC framework. © 2012 Biomedical Engineering Society.link_to_subscribed_fulltex

Identification of Cognitive Workload during Surgical Tasks with Multimodal Deep Learning

The operating room (OR) is a dynamic and complex environment consisting of a multidisciplinary team working together in a high take environment to provide safe and efficient patient care. Additionally, surgeons are frequently exposed to multiple psycho-organisational stressors that may cause negative repercussions on their immediate technical performance and long-term health. Many factors can therefore contribute to increasing the Cognitive Workload (CWL) such as temporal pressures, unfamiliar anatomy or distractions in the OR. In this paper, a cascade of two machine learning approaches is suggested for the multimodal recognition of CWL in four different surgical task conditions. Firstly, a model based on the concept of transfer learning is used to identify if a surgeon is experiencing any CWL. Secondly, a Convolutional Neural Network (CNN) uses this information to identify different degrees of CWL associated to each surgical task. The suggested multimodal approach considers adjacent signals from electroencephalogram (EEG), functional near-infrared spectroscopy (fNIRS) and eye pupil diameter. The concatenation of signals allows complex correlations in terms of time (temporal) and channel location (spatial). Data collection was performed by a Multi-sensing AI Environment for Surgical Task & Role Optimisation platform (MAESTRO) developed at the Hamlyn Centre, Imperial College London. To compare the performance of the proposed methodology, a number of state-of-art machine learning techniques have been implemented. The tests show that the proposed model has a precision of 93%

An eye-tracking based robotic scrub nurse: proof of concept

Background Within surgery, assistive robotic devices (ARD) have reported improved patient outcomes. ARD can offer the surgical team a “third hand” to perform wider tasks and more degrees of motion in comparison with conventional laparoscopy. We test an eye-tracking based robotic scrub nurse (RSN) in a simulated operating room based on a novel real-time framework for theatre-wide 3D gaze localization in a mobile fashion. Methods Surgeons performed segmental resection of pig colon and handsewn end-to-end anastomosis while wearing eye-tracking glasses (ETG) assisted by distributed RGB-D motion sensors. To select instruments, surgeons (ST) fixed their gaze on a screen, initiating the RSN to pick up and transfer the item. Comparison was made between the task with the assistance of a human scrub nurse (HSNt) versus the task with the assistance of robotic and human scrub nurse (R&HSNt). Task load (NASA-TLX), technology acceptance (Van der Laan’s), metric data on performance and team communication were measured. Results Overall, 10 ST participated. NASA-TLX feedback for ST on HSNt vs R&HSNt usage revealed no significant difference in mental, physical or temporal demands and no change in task performance. ST reported significantly higher frustration score with R&HSNt. Van der Laan’s scores showed positive usefulness and satisfaction scores in using the RSN. No significant difference in operating time was observed. Conclusions We report initial findings of our eye-tracking based RSN. This enables mobile, unrestricted hands-free human–robot interaction intra-operatively. Importantly, this platform is deemed non-inferior to HSNt and accepted by ST and HSN test users

A Game Theoretical Method for Cost-Benefit Analysis of Malware Dissemination Prevention

Copyright © Taylor & Francis Group, LLC. Literature in malware proliferation focuses on modeling and analyzing its spread dynamics. Epidemiology models, which are inspired by the characteristics of biological disease spread in human populations, have been used against this threat to analyze the way malware spreads in a network. This work presents a modified version of the commonly used epidemiology models Susceptible Infected Recovered (SIR) and Susceptible Infected Susceptible (SIS), which incorporates the ability to capture the relationships between nodes within a network, along with their effect on malware dissemination process. Drawing upon a model that illustrates the network’s behavior based on the attacker’s and the defender’s choices, we use game theory to compute optimal strategies for the defender to minimize the effect of malware spread, at the same time minimizing the security cost. We consider three defense mechanisms: patch, removal, and patch and removal, which correspond to the defender’s strategy and use probabilistically with a certain rate. The attacker chooses the type of attack according to its effectiveness and cost. Through the interaction between the two opponents we infer the optimal strategy for both players, known as Nash Equilibrium, evaluating the related payoffs. Hence, our model provides a cost-benefit risk management framework for managing malware spread in computer networks

Trajetórias fiscais na América Latina: Um estudo preliminar

Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Economia, Sociedade e Política da Universidade Federal da Integração Latino- Americana, como requisito parcial à obtenção do título de Bacharel em Ciências Econômicas – Economia, Integração e Desenvolvimento.Por trás de certa unidade cultural e linguística que caracteriza a América Latina, escondem-se diferenças nacionais e regionais bastante relevantes. Uma dessas dimensões consiste na questão fiscal. O presente trabalho expõe os resultados de um largo esforço sistemático orientado a compilar dados e produzir indicadores chave para a descrição e análise das mudanças fiscais experimentadas por alguns países latino-americanos ao longo dos séculos XIX e XX. Este trabalho foi construído a partir do levantamento de dados e sistematização de séries históricas da trajetória fiscal de quatro países pré-selecionados (Argentina, Brasil, Chile e Colômbia), seguido por uma análise dos dados levantados em consonância com a literatura específica de cada país. O desenvolvimento do presente estudo possibilitou a elaboração de um quadro global da região, em um nível ainda preliminar, o qual deverá ser utilizado como sustentação empírica e metodológica para futuras pesquisas

The impact of expert visual guidance on trainee visual search strategy, visual attention and motor skills

Minimally invasive and robotic surgery changes the capacity for surgical mentors to guide their trainees with the control customary to open surgery. This neuroergonomic study aims to assess a &quot;Collaborative Gaze Channel&quot; (CGC); which detects trainer gazebehavior and displays the point of regard to the trainee. A randomized crossover study was conducted in which twenty subjects performed a simulated robotic surgical task necessitating collaboration either with verbal (control condition) or visual guidance with CGC (study condition). Trainee occipito-parietal (O-P) cortical function was assessed with optical topography (OT) and gaze-behavior was evaluated using video-oculography. Performance during gaze-assistance was significantly superior [biopsy number: (mean ± SD): control = 5.6 ± 1.8 vs. CGC = 6.6 ± 2.0; p &lt; 0.05] and was associated with significantly lower O-P cortical activity [ HbO 2 mMol × cm [median (IQR)] control = 2.5 (12.0) vs. CGC 0.63 (11.2), p &lt; 0.001]. A random effect model (REM) confirmed the association between guidance mode and O-P excitation. Network cost and global efficiency were not significantly influenced by guidance mode. A gaze channel enhances performance, modulates visual search, and alleviates the burden in brain centers subserving visual attention and does not induce changes in the trainee&apos;s O-P functional network observable with the current OT technique. The results imply that through visual guidance, attentional resources may be liberated, potentially improving the capability of trainees to attend to other safety critical events during the procedure