Photoelastic Stress Analysis Error Quantification in Vasculature Models for Robot Feedback Control

Abstract-Real-time and accurate stress calculation in walls of vasculature is desired to provide catheter insertion robots of feedback control without changing the catheter stiffness and lumen. This feedback source has also applications in endovascular surgery simulation for human skills and medical tools evaluation. For that purpose we consider photoelastic effect, as birefringence produced by light retardation relates with the stress inside the photoelastic materials. In this research a polariscope was designed for urethane elastomer vasculature models, the photoelastic coefficient of urethane elastomer was measured, and the camera system was calibrated to quantify and reduce error of the measurement system. An average error of 3.6% was found for the pressure range of 70-189 mmHg inside the model of urethane elastomer, this enables to calculate accurately stress in vasculature models during Human Blood Pressure Simulation (HBPS). That way we will be able to compare in a closed loop stress produced by HBPS and by the catheter motion when manipulated by a robot. I. INTRODUCTION RAINING with simulators reduces risks of injury and costs during practice for minimally invasive surgery C. Tercero is with Nagoya University, Aiichi-ken Nagoya-shi Chikusa-ku Furo-cho 1, 464-8603 JAPAN (phone: +81-52-788-6013; fax: +81-52-788-6013; e-mail: [email protected]). S. Ikeda is with Nagoya University, Aiichi-ken Nagoya-shi Chikusa-ku Furo-cho 1, 464-8603 JAPAN (phone: +81-52-788-6013; fax: +81-52-788-6013; e-mail: ikeda @robo.mein.nagoya-u.ac.jp). In previous studies photoelastic effect was used with a catheter insertion robot to evaluate catheters In this research we will present a calibration method for the transmittance equation to measure the optical path length, a polariscope designed for our simulation purpose, the deduction of the photoelastic coefficient of urethane elastomer, and the normalization parameters calibration to calculate the principal component of stress in the vasculature model with an inner pressure range of 40-189mmHg. It is desirable to measure stress with an error below 5% for the HBPS range, to use it as reference for control loop illustrated in figure 2. Photoelastic Stress Analysis Error Quantification i

Objective Assessment of Endovascular Navigation Skills with Force Sensing

Despite the increasing popularity of endovascular intervention in clinical practice, there remains a lack of objective and quantitative metrics for skill evaluation of endovascular techniques. Data relating to the forces exerted during endovascular procedures and the behavioral patterns of endovascular clinicians is currently limited. This research proposes two platforms for measuring tool forces applied by operators and contact forces resulting from catheter–tissue interactions, as a means of providing accurate, objective metrics of operator skill within a realistic simulation environment. Operator manipulation patterns are compared across different experience levels performing various complex catheterization tasks, and different performance metrics relating to tool forces, catheter motion dynamics, and forces exerted on the vasculature are extracted. The results depict significant differences between the two experience groups in their force and motion patterns across different phases of the procedures, with support vector machine (SVM) classification showing cross-validation accuracies as high as 90% between the two skill levels. This is the first robust study, validated across a large pool of endovascular specialists, to present objective measures of endovascular skill based on exerted forces. The study also provides significant insights into the design of optimized metrics for improved training and performance assessment of catheterization tasks

PHYSICAL MODELING OF THE KRAUKLIS WAVES: INSIGHTS FROM TWO EXPERIMENTAL APPARATUSES

Fractures play an important role in the geological related processes such as hydraulic fracturing, water-water disposal, and volcanic earthquake. Seismic waves can provide useful information from fractures at a relatively low cost. In particular, the acoustic property of fractures containing magmatic or hydrothermal fluids can provide useful information about the fracture size and the fluid composition within the fracture. For instance, in volcanology, the resonant frequency of long-period events that are linked to crack interface waves is used to obtain fluid properties of cracks in magmatic systems. However, in order to rely on seismic data, they should be precisely characterized in advance. Experimental studies are one of the most important resources to describe and understand physical systems. They are even used to validate analytical and numerical methods. In this dissertation, I aim to gain more insight into the crack waves that are slow guided waves in fluid-filled fractures and are characterized by their dispersive and resonating nature. We will develop two experimental setups. Using the first apparatus that employs the photoelasticity technique, we will visualize the stress regime of the fracture due to the motion, transmission, and reflection pattern of the crack wave. Using the second apparatus which is an acoustic data acquisition system, we extend the fracture of two parallel plates to a more complex and realistic fracture by modifying the fracture stiffness, saturated fluid and fracture geometry, and fracture surface roughness. We evaluate the dispersion and resonance properties of the crack waves under different environments. In addition, some present analytical and numerical models will be evaluated

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018

Advancements and Breakthroughs in Ultrasound Imaging

Ultrasonic imaging is a powerful diagnostic tool available to medical practitioners, engineers and researchers today. Due to the relative safety, and the non-invasive nature, ultrasonic imaging has become one of the most rapidly advancing technologies. These rapid advances are directly related to the parallel advancements in electronics, computing, and transducer technology together with sophisticated signal processing techniques. This book focuses on state of the art developments in ultrasonic imaging applications and underlying technologies presented by leading practitioners and researchers from many parts of the world

Libro de actas. XXXV Congreso Anual de la Sociedad Española de Ingeniería Biomédica

596 p.CASEIB2017 vuelve a ser el foro de referencia a nivel nacional para el intercambio científico de conocimiento, experiencias y promoción de la I D i en Ingeniería Biomédica. Un punto de encuentro de científicos, profesionales de la industria, ingenieros biomédicos y profesionales clínicos interesados en las últimas novedades en investigación, educación y aplicación industrial y clínica de la ingeniería biomédica. En la presente edición, más de 160 trabajos de alto nivel científico serán presentados en áreas relevantes de la ingeniería biomédica, tales como: procesado de señal e imagen, instrumentación biomédica, telemedicina, modelado de sistemas biomédicos, sistemas inteligentes y sensores, robótica, planificación y simulación quirúrgica, biofotónica y biomateriales. Cabe destacar las sesiones dedicadas a la competición por el Premio José María Ferrero Corral, y la sesión de competición de alumnos de Grado en Ingeniería biomédica, que persiguen fomentar la participación de jóvenes estudiantes e investigadores

Development of a Physical Simulation of the Human Defecatory System for the Investigation of Continence Mechanisms

Faecal incontinence is a highly debilitating condition, prevalent across the population worldwide. Coupled with a large unmet need for clinically viable treatment options, a paucity of research into the biomechanics of continence inhibits the development of treatments which address multi-faceted challenges associated with the condition. Consequently, this thesis presents a method to fabricate, measure and control a physical simulation of the human defecatory system to investigate individual and combined effects of anorectal angle and sphincter pressure on continence. To illustrate the capabilities and clinical relevance of the work, the influence of a passive-assistive artificial anal sphincter (FENIX) is evaluated. A model rectum and associated soft tissues, based on geometry from an anonymised computerised tomography dataset, was fabricated from silicone and showed behavioural realism in terms of their morphology to the biological system and ex-vivo tissue. Simulated stool matter with similar rheological properties to human faeces was developed. Instrumentation and control hardware were used to regulate injection of simulated stool into the system, define the anorectal angle and monitor stool flow rate, intra-rectal pressure, anal canal pressure and puborectalis force. Studies were conducted to examine the response of anorectal angles at 80°, 90° and 100° with simulated stool. Tests were then repeated with the inclusion of a FENIX device. Stool leakage was reduced as the anorectal angle became more acute. Conversely, intra-rectal pressure increased. Overall inclusion of the FENIX reduced faecal leakage, while combined effects of the FENIX and an acute anorectal angle showed the greatest resistance to faecal leakage. These data demonstrate that the anorectal angle and sphincter pressure are fundamental in maintaining continence. Furthermore it demonstrates that use of the FENIX can increase resistance to faecal leakage and reduce anorectal angles required to maintain continence. The physical simulation of the defecatory system is an insightful tool to better understand, in a quantitative manner, the effects of the anorectal angle and sphincter pressure on continence. This work is valuable in helping improve our understanding of the physical behaviour of the continence mechanism and facilitating improved technologies to treat severe faecal incontinence