1,019 research outputs found
Assessment of Electromagnetic Tracking Accuracy for Endoscopic Ultrasound
Endoscopic ultrasound (EUS) is a minimally-invasive imaging technique that can be technically difficult to perform due to the small field of view and uncertainty in the endoscope position. Electromagnetic (EM) tracking is emerging as an important technology in guiding endoscopic interventions and for training in endotherapy by providing information on endoscope location by fusion with pre-operative images. However, the accuracy of EM tracking could be compromised by the endoscopic ultrasound transducer. In this work, we quantify the precision and accuracy of EM tracking sensors inserted into the working channel of a flexible endoscope, with the ultrasound transducer turned on and off. The EUS device was found to have little (no significant) effect on static tracking accuracy although jitter increased significantly. A significant change in the measured distance between sensors arranged in a fixed geometry was found during a dynamic acquisition. In conclusion, EM tracking accuracy was not found to be significantly affected by the flexible endoscope
Systems and technologies for objective evaluation of technical skills in laparoscopic surgery
Minimally invasive surgery is a highly demanding surgical approach regarding technical requirements for the surgeon, who must be trained in order to perform a safe surgical intervention. Traditional surgical education in minimally invasive surgery is commonly based on subjective criteria to quantify and evaluate surgical abilities, which could be potentially unsafe for the patient. Authors, surgeons and associations are increasingly demanding the development of more objective assessment tools that can accredit surgeons as technically competent. This paper describes the state of the art in objective assessment methods of surgical skills. It gives an overview on assessment systems based on structured checklists and rating scales, surgical simulators, and instrument motion analysis. As a future work, an objective and automatic assessment method of surgical skills should be standardized as a means towards proficiency-based curricula for training in laparoscopic surgery and its certification
Evolutionarily Optimized Electromagnetic Sensor Measurements for Robust Surgical Navigation
© 2001-2012 IEEE. Miniaturized electromagnetic sensors are increasingly introduced to navigate surgical instruments to anatomical targets during minimally invasive procedures, such as endoscopic surgery. These sensors are usually attached at the distal tips of surgical instruments to track their three-dimensional motion represented by the position and orientation in six degrees of freedom. Unfortunately, these sensors suffer from inaccurate measurements and jitter errors due to the patient movement (e.g., respiratory motion) and magnetic field distortion. This paper proposes an evolutionary computing strategy to optimize the sensor measurements and improve the tracking accuracy of surgical navigation. We modified two evolutionary computation algorithms and proposed adaptive particle swarm optimization (APSO) and observation-boosted differential evolution (OBDE) to enhance the navigation accuracy. The experimental results demonstrate that our modified algorithms to evolutionarily optimize electromagnetic sensor measurements can critically reduce the tracking error from 4.8 to 2.9 mm. In particular, OBDE outperforms APSO for electromagnetic endoscopic navigation
Advanced Endoscopic Navigation:Surgical Big Data,Methodology,and Applications
随着科学技术的飞速发展,健康与环境问题日益成为人类面临的最重大问题之一。信息科学、计算机技术、电子工程与生物医学工程等学科的综合应用交叉前沿课题,研究现代工程技术方法,探索肿瘤癌症等疾病早期诊断、治疗和康复手段。本论文综述了计算机辅助微创外科手术导航、多模态医疗大数据、方法论及其临床应用:从引入微创外科手术导航概念出发,介绍了医疗大数据的术前与术中多模态医学成像方法、阐述了先进微创外科手术导航的核心流程包括计算解剖模型、术中实时导航方案、三维可视化方法及交互式软件技术,归纳了各类微创外科手术方法的临床应用。同时,重点讨论了全球各种手术导航技术在临床应用中的优缺点,分析了目前手术导航领域内的最新技术方法。在此基础上,提出了微创外科手术方法正向数字化、个性化、精准化、诊疗一体化、机器人化以及高度智能化的发展趋势。【Abstract】Interventional endoscopy (e.g., bronchoscopy, colonoscopy, laparoscopy, cystoscopy) is a widely performed procedure that involves either diagnosis of suspicious lesions or guidance for minimally invasive surgery in a variety of organs within the body cavity. Endoscopy may also be used to guide the introduction of certain items (e.g., stents) into the body. Endoscopic navigation systems seek to integrate big data with multimodal information (e.g., computed tomography, magnetic resonance images, endoscopic video sequences, ultrasound images, external trackers) relative to the patient's anatomy, control the movement of medical endoscopes and surgical tools, and guide the surgeon's actions during endoscopic interventions. Nevertheless, it remains challenging to realize the next generation of context-aware navigated endoscopy. This review presents a broad survey of various aspects of endoscopic navigation, particularly with respect to the development of endoscopic navigation techniques. First, we investigate big data with multimodal information involved in endoscopic navigation. Next, we focus on numerous methodologies used for endoscopic navigation. We then review different endoscopic procedures in clinical applications. Finally, we discuss novel techniques and promising directions for the development of endoscopic navigation.X.L. acknowledges funding from the Fundamental Research Funds for the Central Universities. T.M.P. acknowledges funding from the Canadian Foundation for Innovation, the Canadian Institutes for Health Research, the National Sciences and Engineering Research Council of Canada, and a grant from Intuitive Surgical Inc
Ureteroscopy-assisted percutaneous kidney access made easy: first clinical experience with a novel navigation system using electromagnetic guidance (IDEAL Stage 1)
Background: Puncture of the renal collecting system represents a challenging step in percutaneous nephrolithotomy (PCNL). Limitations related to the use of standard fluoroscopic-based and ultrasound-based maneuvers have been recognized. Objectives: To describe the technique and early clinical outcomes of a novel navigation system for percutaneous kidney access. Design, setting, and participants: This was a proof-of-concept study (IDEAL phase 1) conducted at a single academic center. Ten PCNL procedures were performed for patients with kidney stones. Surgical procedure: Flexible ureterorenoscopy was performed to determine the optimal renal calyx for access. An electromagnetic sensor was inserted through the working channel. Then the selected calyx was punctured with a needle with a sensor on the tip guided by real-time three-dimensional images observed on the monitor. Outcome measurements and statistical analysis: The primary endpoints were the accuracy and clinical applicability of the system in clinical use. Secondary endpoints were the time to successful puncture, the number of attempts for successful puncture, and complications. Results and limitations: Ten patients were enrolled in the study. The median age was 47.1 yr (30-63), median body mass index was 22.85 kg/m(2) (19-28.3), and median stone size was 2.13 cm (1.5-2.5 cm). All stones were in the renal pelvis. The Guy's stone score was 1 in nine cases and 2 in one case. All 10 punctures of the collecting system were successfully completed at the first attempt without X-ray exposure. The median time to successful puncture starting from insertion of the needle was 20 s (range 15-35). No complications occurred.
Conclusions: We describe the first clinical application of a novel navigation system using real-time electromagnetic sensors for percutaneous kidney access. This new technology overcomes the intrinsic limitations of traditional methods of kidney access, allowing safe, precise, fast, and effective puncture of the renal collecting system. Patient summary: We describe a new technology allowing safe and easy puncture of the kidney without radiation exposure. This could significantly facilitate one of the most challenging steps in percutaneous removal of kidney stones.info:eu-repo/semantics/publishedVersio
Navigation system based in motion tracking sensor for percutaneous renal access
Tese de Doutoramento em Engenharia BiomédicaMinimally-invasive kidney interventions are daily performed to diagnose and treat several renal
diseases. Percutaneous renal access (PRA) is an essential but challenging stage for most of these
procedures, since its outcome is directly linked to the physician’s ability to precisely visualize and
reach the anatomical target.
Nowadays, PRA is always guided with medical imaging assistance, most frequently using X-ray
based imaging (e.g. fluoroscopy). Thus, radiation on the surgical theater represents a major risk to
the medical team, where its exclusion from PRA has a direct impact diminishing the dose exposure
on both patients and physicians.
To solve the referred problems this thesis aims to develop a new hardware/software framework
to intuitively and safely guide the surgeon during PRA planning and puncturing.
In terms of surgical planning, a set of methodologies were developed to increase the certainty of
reaching a specific target inside the kidney. The most relevant abdominal structures for PRA were
automatically clustered into different 3D volumes. For that, primitive volumes were merged as a local
optimization problem using the minimum description length principle and image statistical
properties. A multi-volume Ray Cast method was then used to highlight each segmented volume.
Results show that it is possible to detect all abdominal structures surrounding the kidney, with the
ability to correctly estimate a virtual trajectory.
Concerning the percutaneous puncturing stage, either an electromagnetic or optical solution
were developed and tested in multiple in vitro, in vivo and ex vivo trials. The optical tracking solution
aids in establishing the desired puncture site and choosing the best virtual puncture trajectory.
However, this system required a line of sight to different optical markers placed at the needle base,
limiting the accuracy when tracking inside the human body. Results show that the needle tip can
deflect from its initial straight line trajectory with an error higher than 3 mm. Moreover, a complex
registration procedure and initial setup is needed.
On the other hand, a real-time electromagnetic tracking was developed. Hereto, a catheter
was inserted trans-urethrally towards the renal target. This catheter has a position and orientation
electromagnetic sensor on its tip that function as a real-time target locator. Then, a needle integrating a similar sensor is used. From the data provided by both sensors, one computes a virtual puncture
trajectory, which is displayed in a 3D visualization software. In vivo tests showed a median renal and
ureteral puncture times of 19 and 51 seconds, respectively (range 14 to 45 and 45 to 67 seconds).
Such results represent a puncture time improvement between 75% and 85% when comparing to
state of the art methods.
3D sound and vibrotactile feedback were also developed to provide additional information about
the needle orientation. By using these kind of feedback, it was verified that the surgeon tends to
follow a virtual puncture trajectory with a reduced amount of deviations from the ideal trajectory,
being able to anticipate any movement even without looking to a monitor. Best results show that 3D
sound sources were correctly identified 79.2 ± 8.1% of times with an average angulation error of
10.4º degrees. Vibration sources were accurately identified 91.1 ± 3.6% of times with an average
angulation error of 8.0º degrees.
Additionally to the EMT framework, three circular ultrasound transducers were built with a needle
working channel. One explored different manufacture fabrication setups in terms of the piezoelectric
materials, transducer construction, single vs. multi array configurations, backing and matching
material design. The A-scan signals retrieved from each transducer were filtered and processed to
automatically detect reflected echoes and to alert the surgeon when undesirable anatomical
structures are in between the puncture path. The transducers were mapped in a water tank and
tested in a study involving 45 phantoms. Results showed that the beam cross-sectional area
oscillates around the ceramics radius and it was possible to automatically detect echo signals in
phantoms with length higher than 80 mm.
Hereupon, it is expected that the introduction of the proposed system on the PRA procedure,
will allow to guide the surgeon through the optimal path towards the precise kidney target, increasing
surgeon’s confidence and reducing complications (e.g. organ perforation) during PRA. Moreover, the
developed framework has the potential to make the PRA free of radiation for both patient and surgeon
and to broad the use of PRA to less specialized surgeons.Intervenções renais minimamente invasivas são realizadas diariamente para o tratamento e
diagnóstico de várias doenças renais. O acesso renal percutâneo (ARP) é uma etapa essencial e
desafiante na maior parte destes procedimentos. O seu resultado encontra-se diretamente
relacionado com a capacidade do cirurgião visualizar e atingir com precisão o alvo anatómico.
Hoje em dia, o ARP é sempre guiado com recurso a sistemas imagiológicos, na maior parte
das vezes baseados em raios-X (p.e. a fluoroscopia). A radiação destes sistemas nas salas cirúrgicas
representa um grande risco para a equipa médica, aonde a sua remoção levará a um impacto direto
na diminuição da dose exposta aos pacientes e cirurgiões.
De modo a resolver os problemas existentes, esta tese tem como objetivo o desenvolvimento
de uma framework de hardware/software que permita, de forma intuitiva e segura, guiar o cirurgião
durante o planeamento e punção do ARP.
Em termos de planeamento, foi desenvolvido um conjunto de metodologias de modo a
aumentar a eficácia com que o alvo anatómico é alcançado. As estruturas abdominais mais
relevantes para o procedimento de ARP, foram automaticamente agrupadas em volumes 3D, através
de um problema de optimização global com base no princípio de “minimum description length” e
propriedades estatísticas da imagem. Por fim, um procedimento de Ray Cast, com múltiplas funções
de transferência, foi utilizado para enfatizar as estruturas segmentadas. Os resultados mostram que
é possível detetar todas as estruturas abdominais envolventes ao rim, com a capacidade para
estimar corretamente uma trajetória virtual.
No que diz respeito à fase de punção percutânea, foram testadas duas soluções de deteção
de movimento (ótica e eletromagnética) em múltiplos ensaios in vitro, in vivo e ex vivo. A solução
baseada em sensores óticos ajudou no cálculo do melhor ponto de punção e na definição da melhor
trajetória a seguir. Contudo, este sistema necessita de uma linha de visão com diferentes
marcadores óticos acoplados à base da agulha, limitando a precisão com que a agulha é detetada
no interior do corpo humano. Os resultados indicam que a agulha pode sofrer deflexões à medida
que vai sendo inserida, com erros superiores a 3 mm.
Por outro lado, foi desenvolvida e testada uma solução com base em sensores
eletromagnéticos. Para tal, um cateter que integra um sensor de posição e orientação na sua ponta, foi colocado por via trans-uretral junto do alvo renal. De seguida, uma agulha, integrando um sensor
semelhante, é utilizada para a punção percutânea. A partir da diferença espacial de ambos os
sensores, é possível gerar uma trajetória de punção virtual. A mediana do tempo necessário para
puncionar o rim e ureter, segundo esta trajetória, foi de 19 e 51 segundos, respetivamente
(variações de 14 a 45 e 45 a 67 segundos). Estes resultados representam uma melhoria do tempo
de punção entre 75% e 85%, quando comparados com o estado da arte dos métodos atuais.
Além do feedback visual, som 3D e feedback vibratório foram explorados de modo a fornecer
informações complementares da posição da agulha. Verificou-se que com este tipo de feedback, o
cirurgião tende a seguir uma trajetória de punção com desvios mínimos, sendo igualmente capaz
de antecipar qualquer movimento, mesmo sem olhar para o monitor. Fontes de som e vibração
podem ser corretamente detetadas em 79,2 ± 8,1% e 91,1 ± 3,6%, com erros médios de angulação
de 10.4º e 8.0 graus, respetivamente.
Adicionalmente ao sistema de navegação, foram também produzidos três transdutores de
ultrassom circulares com um canal de trabalho para a agulha. Para tal, foram exploradas diferentes
configurações de fabricação em termos de materiais piezoelétricos, transdutores multi-array ou
singulares e espessura/material de layers de suporte. Os sinais originados em cada transdutor
foram filtrados e processados de modo a detetar de forma automática os ecos refletidos, e assim,
alertar o cirurgião quando existem variações anatómicas ao longo do caminho de punção. Os
transdutores foram mapeados num tanque de água e testados em 45 phantoms. Os resultados
mostraram que o feixe de área em corte transversal oscila em torno do raio de cerâmica, e que os
ecos refletidos são detetados em phantoms com comprimentos superiores a 80 mm.
Desta forma, é expectável que a introdução deste novo sistema a nível do ARP permitirá
conduzir o cirurgião ao longo do caminho de punção ideal, aumentado a confiança do cirurgião e
reduzindo possíveis complicações (p.e. a perfuração dos órgãos). Além disso, de realçar que este
sistema apresenta o potencial de tornar o ARP livre de radiação e alarga-lo a cirurgiões menos
especializados.The present work was only possible thanks to the support by the Portuguese Science and
Technology Foundation through the PhD grant with reference SFRH/BD/74276/2010 funded by
FCT/MEC (PIDDAC) and by Fundo Europeu de Desenvolvimento Regional (FEDER), Programa
COMPETE - Programa Operacional Factores de Competitividade (POFC) do QREN
Methods and Tools for Objective Assessment of Psychomotor Skills in Laparoscopic Surgery
Training and assessment paradigms for laparoscopic surgical skills are evolving from traditional mentor–trainee tutorship towards structured, more objective and safer programs. Accreditation of surgeons requires reaching a consensus on metrics and tasks used to assess surgeons’ psychomotor skills. Ongoing development of tracking systems and software solutions has allowed for the expansion of novel training and assessment means in laparoscopy. The current challenge is to adapt and include these systems within training programs, and to exploit their possibilities for evaluation purposes. This paper describes the state of the art in research on measuring and assessing psychomotor laparoscopic skills. It gives an overview on tracking systems as well as on metrics and advanced statistical and machine learning techniques employed for evaluation purposes. The later ones have a potential to be used as an aid in deciding on the surgical competence level, which is an important aspect when accreditation of the surgeons in particular, and patient safety in general, are considered. The prospective of these methods and tools make them complementary means for surgical assessment of motor skills, especially in the early stages of training. Successful examples such as the Fundamentals of Laparoscopic Surgery should help drive a paradigm change to structured curricula based on objective parameters. These may improve the accreditation of new surgeons, as well as optimize their already overloaded training schedules
ADVANCED IMAGING AND ROBOTICS TECHNOLOGIES FOR MEDICAL APPLICATIONS
Due to the importance of surgery in the medical field, a large amount of research has been conducted in this area. Imaging and robotics technologies provide surgeons with the advanced eye and hand to perform their surgeries in a safer and more accurate manner. Recently medical images have been utilized in the operating room as well as in the diagnostic stage. If the image to patient registration is done with sufficient accuracy, medical images can be used as "a map" for guidance to the target lesion. However, the accuracy and reliability of the surgical navigation system should be sufficiently verified before applying it to the patient. Along with the development of medical imaging, various medical robots have also been developed. In particular, surgical robots have been researched in order to reach the goal of minimal invasiveness. The most important factors to consider are determining the demand, the strategy for their use in operating procedures, and how it aids patients. In addition to the above considerations, medical doctors and researchers should always think from the patient's point of view. In this article, the latest medical imaging and robotic technologies focusing on surgical applications are reviewed based upon the factors described in the above. © 2011 Copyright Taylor and Francis Group, LLC.1
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