34 research outputs found
Kidney targeting and puncturing during percutaneous nephrolithotomy: recent advances and future perspectives
Background and Purpose:
Precise needle puncture of the kidney is a challenging and essential step for successful percutaneous nephrolithotomy (PCNL). Many devices and surgical techniques have been developed to easily achieve suitable renal access. This article presents a critical review to address the methodologies and techniques for conducting kidney targeting and the puncture step during PCNL. Based on this study, research paths are also provided for PCNL procedure improvement.
METHODS:
Most relevant works concerning PCNL puncture were identified by a search of Medline/PubMed, ISI Web of Science, and Scopus databases from 2007 to December 2012. Two authors independently reviewed the studies.
RESULTS:
A total of 911 abstracts and 346 full-text articles were assessed and discussed; 52 were included in this review as a summary of the main contributions to kidney targeting and puncturing.
CONCLUSIONS:
Multiple paths and technologic advances have been proposed in the field of urology and minimally invasive surgery to improve PCNL puncture. The most relevant contributions, however, have been provided by the application of medical imaging guidance, new surgical tools, motion tracking systems, robotics, and image processing and computer graphics. Despite the multiple research paths for PCNL puncture guidance, no widely acceptable solution has yet been reached, and it remains an active and challenging research field. Future developments should focus on real-time methods, robust and accurate algorithms, and radiation free imaging techniques.The authors acknowledge Foundation for Science and Technology (FCT) for the fellowships references: SFRH/BPD/46851/2008 and SFRH/BD/74276/2010
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
Minimally Invasive Urological Procedures and Related Technological Developments
The landscape of minimally invasive urological intervention is changing. A lot of new innovations and technological developments have happened over the last 3 decades. Laparoscopy and robotic surgery have revolutionised kidney and prostate cancer treatment, with more minimally invasive procedures now being carried out than ever before. At the same time, technological advancements and the use of laser have changed the face of endourology. Several new innovative treatments are now commonplace for benign prostate enlargement (BPE). Management of prostate cancer now involves procedures such as robotic prostatectomy, brachytherapy, radiotherapy, cryotherapy and HIFU. Robotic partial nephrectomy and cryotherapy have changed the face of renal cancer. En-bloc resection of bladder cancer is challenging the traditional management of non-muscle invasive bladder cancer and becoming commonplace, while robotic cystectomy is also gaining popularity for muscle invasive bladder cancer. Newer surgical intervention related to BPE includes laser (holmium, thulium and green light), water-based treatment (Rezum, Aquablation) and other minimally invasive procedures such as prostate artery embolisation (PAE) and Urolift. Endourological procedures have incorporated newer laser types and settings such as moses technology, disposable ureteroscopes (URS) and minimisation of percutaneous nephrolithotomy (PCNL) instruments. All these technological innovations and improvements have led to shorter hospital stay, reduced cost, potential reduction in complications and improvement in the quality of life (QoL)
Research on real-time physics-based deformation for haptic-enabled medical simulation
This study developed a multiple effective visuo-haptic surgical engine to handle a variety of surgical manipulations in real-time. Soft tissue models are based on biomechanical experiment and continuum mechanics for greater accuracy. Such models will increase the realism of future training systems and the VR/AR/MR implementations for the operating room
Application of mixed reality to ultrasound-guided femoral arterial cannulation during real-time practice in cardiac interventions
Producción CientíficaMixed reality opens interesting possibilities as it allows physicians to interact with both, the real physical and the virtual computer-generated environment and objects, in a powerful way. A mixed reality system, based in the HoloLens 2 glasses, has been developed to assist cardiologists in a quite complex interventional procedure: the ultrasound-guided femoral arterial cannulations, during real-time practice in interventional cardiology. The system is divided into two modules, the transmitter module, responsible for sending medical images to HoloLens 2 glasses, and the receiver module, hosted in the HoloLens 2, which renders those medical images, allowing the practitioner to watch and manage them in a 3D environment. The system has been successfully used, between November 2021 and August 2022, in up to 9 interventions by 2 different practitioners, in a large public hospital in central Spain. The practitioners using the system confirmed it as easy to use, reliable, real-time, reachable, and cost-effective, allowing a reduction of operating times, a better control of typical errors associated to the interventional procedure, and opening the possibility to use the medical imagery produced in ubiquitous e-learning. These strengths and opportunities were only nuanced by the risk of potential medical complications emerging from system malfunction or operator errors when using the system (e.g., unexpected momentary lag). In summary, the proposed system can be taken as a realistic proof of concept of how mixed reality technologies can support practitioners when performing interventional and surgical procedures during real-time daily practice.Junta de Castilla y León - Gerencia Regional de Salud (SACyL) (grant number GRS 2275/A/2020)Instituto de Salud Carlos III (grant number DTS21/00158)Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL
Patient-Specific 3D Printed Models for Education, Research and Surgical Simulation
3D printing techniques are increasingly used in engineering science, allowing the use of computer aided design (CAD) to rapidly and inexpensively create prototypes and components. There is also growing interest in the application of these techniques in a clinical context for the creation of anatomically accurate 3D printed models from medical images for therapy planning, research, training and teaching applications. However, the techniques and tools available to create 3D models of anatomical structures typically require specialist knowledge in image processing and mesh manipulation to achieve. In this book chapter we describe the advantages of 3D printing for patient education, healthcare professional education, interventional planning and implant development. We also describe how to use medical image data to segment volumes of interest, refine and prepare for 3D printing. We will use a lung as an example. The information in this section will allow anyone to create own 3D printed models from medical image data. This knowledge will be of use to anyone with little or no previous experience in medical image processing who have identified a potential application for 3D printing in a medical context, or those with a more general interest in the techniques