Prospective study for commercial and low-cost hyperspectral imaging systems to evaluate thermal tissue effect on bovine liver samples

Thermal ablation modalities, for example radiofrequency ablation (RFA) and microwave ablation, are intended to prompt controlled tumour removal by raising tissue temperature. However, monitoring the size of the resulting tissue damage during the thermal removal procedures is a challenging task. The objective of this study was to evaluate the observation of RFA on an ex vivo liver sample with both a commercial and a low-cost system to distinguish between the normal and the ablated regions as well as the thermally affected regions. RFA trials were conducted on five different ex vivo normal bovine samples and monitored initially by a custom hyperspectral (HS) camera to measure the diffuse reflectance (Rd) utilising a polychromatic light source (tungsten halogen lamp) within the spectral range 348–950 nm. Next, the light source was replaced with monochromatic LEDs (415, 565 and 660 nm) and a commercial charge-coupled device (CCD) camera was used instead of the HS camera. The system algorithm comprises image enhancement (normalisation and moving average filter) and image segmentation with K-means clustering, combining spectral and spatial information to assess the variable responses to polychromatic light and monochromatic LEDs to highlight the differences in the Rd properties of thermally affected/normal tissue regions. The measured spectral signatures of the various regions, besides the calculation of the standard deviations (δ) between the generated six groups, guided us to select three optimal wavelengths (420, 540 and 660 nm) to discriminate between these various regions. Next, we selected six spectral images to apply the image processing to (at 450, 500, 550, 600, 650 and 700 nm). We noticed that the optimum image is the superimposed spectral images at 550, 600, 650 and 700 nm, which are capable of discriminating between the various regions. Later, we measured Rd with the CCD camera and commercially available monochromatic LED light sources at 415, 565 and 660 nm. Compared to the HS camera results, this system was more capable of identifying the ablated and the thermally affected regions of surface RFA than the side-penetration RFA of the investigated ex vivo liver samples. However, we succeeded in developing a low-cost system that provides satisfactory information to highlight the ablated and thermally affected region to improve the outcome of surgical tumour ablation with much shorter time for image capture and processing compared to the HS system

Development of a near-infrared (NIR) forearm subcutaneous vein extraction using deep residual u-net

Impotence to locate the forearm subcutaneous vein leads to multiple intravenous (IV) attempts causing pain and injuries to patients such as bruise or vein damages. Various technologies and techniques were proposed and developed to overcome the multiple IV access problems. The standard techniques used in research and hospitals are Transillumination, Ultrasound Imaging, and Near-Infrared (NIR). Among those techniques, NIR is the most optimal way of locating the subcutaneous vein because of its non-invasive properties, low-cost implementation. The device can be assembled in a small size product. Nevertheless, the NIR forearm images contain noises that cause difficulties in extracting the vein features. Hence, the performance of NIR vein extraction is having the bottleneck of detecting the vein pixel accurately. Many research studies have been conducted to work on the NIR forearm subcutaneous vein detection due to such a limitation. Artificial intelligence is one of the powerful technology that would benefit this study. However, a limited number of articles were found on the patentability search, and thus we propose an automatic vein extraction algorithm using Deep Residual U-Net architecture. Our algorithm shows 75 percent of the accuracy in extracting the NIR vein from the experiments that tested. These results show the evidence that the Deep Residual U-Net can be applied to extract the NIR vein

Blood

This book examines both the fluid and cellular components of blood. After the introductory section, the second section presents updates on various topics in hemodynamics. Chapters in this section discuss anemia, 4D flow MRI in cardiology, cardiovascular complications of robot-assisted laparoscopic pelvic surgery, altered perfusion in multiple sclerosis, and hemodynamic laminar shear stress in oxidative homeostasis. The third section focuses on thalassemia with chapters on diagnosis and screening for thalassemia, high blood pressure in beta-thalassemia, and hepatitis C infection in thalassemia patients

Nonlinear effects in finite elements analysis of colorectal surgical clamping

Minimal Invasive Surgery (MIS) is a procedure that has increased its applications in past few years in different types of surgeries. As number of application fields are increasing day by day, new issues have been arising. In particular, instruments must be inserted through a trocar to access the abdominal cavity without capability of direct manipulation of tissues, so a loss of sensitivity occurs. Generally speaking, the student of medicine or junior surgeons need a lot of practice hours before starting any surgical procedure, since they have to difficulty in acquiring specific skills (hand–eye coordination among others) for this type of surgery. Here is what the surgical simulator present a promising training method using an approach based on Finite Element Method (FEM). The use of continuum mechanics, especially Finite Element Analysis (FEA) has gained an extensive application in medical field in order to simulate soft tissues. In particular, colorectal simulations can be used to understand the interaction between colon and the surrounding tissues and also between colon and instruments. Although several works have been introduced considering small displacements, FEA applied to colorectal surgical procedures with large displacements is a topic that asks for more investigations. This work aims to investigate how FEA can describe non-linear effects induced by material properties and different approximating geometries, focusing as test-case application colorectal surgery. More in detail, it shows a comparison between simulations that are performed using both linear and hyperelastic models. These different mechanical behaviours are applied on different geometrical models (planar, cylindrical, 3D-SS and a real model from digital acquisitions 3D-S) with the aim of evaluating the effects of geometric non-linearity. Final aim of the research is to provide a preliminary contribution to the simulation of the interaction between surgical instrument and colon tissues with multi-purpose FEA in order to help the preliminary set-up of different bioengineering tasks like force-contact evaluation or approximated modelling for virtual reality (surgical simulations). In particular, the contribution of this work is focused on the sensitivity analysis of the nonlinearities by FEA in the tissue-tool interaction through an explicit FEA solver. By doing in this way, we aim to demonstrate that the set-up of FEA computational surgical tools may be simplified in order to provide assistance to non-expert FEA engineers or medicians in more precise way of using FEA tools

Realistic tool-tissue interaction models for surgical simulation and planning

Surgical simulators present a safe and potentially effective method for surgical training, and can also be used in pre- and intra-operative surgical planning. Realistic modeling of medical interventions involving tool-tissue interactions has been considered to be a key requirement in the development of high-fidelity simulators and planners. The soft-tissue constitutive laws, organ geometry and boundary conditions imposed by the connective tissues surrounding the organ, and the shape of the surgical tool interacting with the organ are some of the factors that govern the accuracy of medical intervention planning.\ud \ud This thesis is divided into three parts. First, we compare the accuracy of linear and nonlinear constitutive laws for tissue. An important consequence of nonlinear models is the Poynting effect, in which shearing of tissue results in normal force; this effect is not seen in a linear elastic model. The magnitude of the normal force for myocardial tissue is shown to be larger than the human contact force discrimination threshold. Further, in order to investigate and quantify the role of the Poynting effect on material discrimination, we perform a multidimensional scaling study. Second, we consider the effects of organ geometry and boundary constraints in needle path planning. Using medical images and tissue mechanical properties, we develop a model of the prostate and surrounding organs. We show that, for needle procedures such as biopsy or brachytherapy, organ geometry and boundary constraints have more impact on target motion than tissue material parameters. Finally, we investigate the effects surgical tool shape on the accuracy of medical intervention planning. We consider the specific case of robotic needle steering, in which asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. We present an analytical and finite element (FE) model for the loads developed at the bevel tip during needle-tissue interaction. The analytical model explains trends observed in the experiments. We incorporated physical parameters (rupture toughness and nonlinear material elasticity) into the FE model that included both contact and cohesive zone models to simulate tissue cleavage. The model shows that the tip forces are sensitive to the rupture toughness. In order to model the mechanics of deflection of the needle, we use an energy-based formulation that incorporates tissue-specific parameters such as rupture toughness, nonlinear material elasticity, and interaction stiffness, and needle geometric and material properties. Simulation results follow similar trends (deflection and radius of curvature) to those observed in macroscopic experimental studies of a robot-driven needle interacting with gels

Effect of acute exercise on postprandial lipemia and endothelial function in men with peripheral arterial disease

Introduction: Postprandial lipidemia (PPL), defined as an increase in plasma levels of triglyceride-rich lipoproteins following the consumption of a high fat meal (HFM) is associated with endothelial dysfunction. Acute exercise reduces PPL and maintains endothelial function (EF) in healthy adults. The effect of acute exercise on PPL and endothelial function has not been studied in patients with peripheral arterial disease (PAD). Purpose: To examine the effect of an acute bout of exercise on PPL, vascular inflammation and endothelial function in men with PAD. Methods: Men (n=8) with PAD underwent two oral fat tolerance tests (OFTT). On the evening prior to each OFTT, participants rested (control), or exercised until they expended 200 Kcal. Blood samples were obtained at baseline and 30 min, 1, 2, 3 and 4 h postprandial. Endothelial-dependent dilation (EDD) and endothelial-independent dilation (EID) were measured in the brachial artery using ultrasonography at baseline, 2 h and 4 h postprandial. Results: Postprandial TG increased significantly and EDD decreased significantly following the OFTT. An acute bout of discontinuous exercise that resulted in a 200 Kcal expenditure did not significantly attenuate the post prandial TG response or significantly ameliorate the decrease in endothelial vasomotor function. Compared to baseline values, circulating leukocytes, and TNF-α increased (p<0.05) in both conditions 4 h postprandial. There were no changes in C-Reactive Protein (CRP). Conclusion: Prior exercise has no effect on PPL or EDD following an OFTT in men with PAD

Towards early hemolysis detection: a smartphone based approach

Os especialistas em diagnóstico in vitro (IVDs) têm confiado maioritariamente na inspeção visual (ótica) manual e, em segundo lugar, em sensores óticos ou câmaras embutidas ou dispositivos médicos incorporados que suportam o exame da qualidade da amostra na fase pré-analítica. Com o aumento dos volumes de amostras para serem processadas e dos respetivos dados complexos gerados por esse processamento, aquelas técnicas tornaram-se cada vez mais difíceis de utilizar, ou os respetivos resultados não ficam imediatamente disponíveis. Para superar as complexidades impostas por tais técnicas tradicionais, o aumento do uso de dispositivos móveis e algoritmos de processamento de imagem no setor de saúde abriu caminho para a constituição de novos casos de uso baseados em análises móveis de amostras, pois fornecem uma interação simples e intuitiva com objetos gráficos familiares que são mostrados no ecrã dos smartphones. As interfaces gráficas e as técnicas de interação suportadas por dispositivos móveis podem pois proporcionar ao especialista em IVD uma série de vantagens e valor agregado devido à maior familiaridade com estes dispositivos e à grande acessibilidade que evidenciam atualmente, tendo o potencial de facilitar as análises de amostras. No entanto, o uso sistemático de dispositivos móveis no setor da saúde encontra-se ainda numa fase muito incipiente, em particular na área de IVD. Nesta tese, propõe-se conceber e discutir a arquitetura, a conceção e a implementação de um protótipo de uma aplicação móvel para smartphone (designada por "HemoDetect") que implementa um conjunto sugerido de algoritmos, interfaces e técnicas de interação que foram desenvolvidos com o objetivo de contribuir para a compreensão de técnicas mais eficientes para ajudar a detetar a hemólise, um processo que designa a rotura de glóbulos vermelhos (eritrócitos) e libertação do respetivo conteúdo (citoplasma) para o fluído circundante (por exemplo, plasma sanguíneo), complementando-as com estatísticas e medições de laboratório, mostrando a utilização de um protótipo durante experiências, permitindo assim chegar-se a um conceito viável que permita apoiar eficazmente a deteção precoce de hemólise.In Vitro Diagnostics (IVDs) specialists have been firstly relying on manual visual (optical) inspection and, secondly, on optical sensors or cameras embedded or built-in medical devices which support the examination of sample quality in pre-analytical phase. With increasing sample processing volumes and their generated complex data, these techniques have become increasingly difficult or results are not readily available. In order to overcome the complexities posed by these traditional techniques, the increased usage of mobile devices and algorithms in the healthcare industry paves the way into shaping new use cases and discovery of mobile analysis of samples, as they provide a user-friendly and familiar interaction with objects displayed on their screens. The interfaces and interaction techniques rendered by mobile devices, bring, to the IVD specialist, a number of advantages and added value due to increased familiarity with the devices or their accessibility, which is made easier. However, they are at the beginning of their journey in the healthcare industry, in particular in the IVD and point-of-care areas. In this thesis, the proposal is to discover and discuss the architecture, design and implementation of a smartphone prototype app (called “HemoDetect”) with its algorithms, interfaces and interaction techniques which was developed to help detect hemolysis which represents the rupture of red blood cells (erythrocytes) and release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma), and complementing it with from-the-lab statistics and measurements showing its utilization during experiments, which ultimately may be a feasible concept that could support early hemolysis detection.Les spécialistes du diagnostic in vitro (DIV) se sont d'abord appuyés sur l'inspection visuelle (optique) manuelle et, ensuite, sur des capteurs optiques ou des caméras intégrées ou intégrées à des dispositifs médicaux qui facilitent l'examen de la qualité des échantillons en phase pré-analytique. Avec l'augmentation des volumes de traitement des échantillons et des données complexes générées, ces techniques sont devenues de plus en plus difficiles ou les résultats ne sont pas facilement disponibles. Afin de surmonter les complexités posées par ces techniques traditionnelles, l'utilisation croissante des appareils mobiles et des algorithmes dans le secteur de la santé ouvre la voie à la définition de nouveaux cas d'utilisation et à la découverte d'analyses d'échantillons mobiles, car ils fournissent une interaction conviviale et familière. avec des objets affichés sur leurs écrans. Les interfaces et les techniques d'interaction rendues par les appareils mobiles apportent au spécialiste des dispositifs de DIV un certain nombre d'avantages et de valeur ajoutée en raison d'une familiarisation accrue avec les appareils ou de leur accessibilité, ce qui est facilité. Cependant, ils sont au début de leur parcours dans le secteur de la santé, en particulier dans le domains des DIV et point-of-care. Dans cette thèse, la proposition est de découvrir et de discuter de l’architecture, de la conception et de la mise en oeuvre d’une application pour smartphone (appelée «HemoDetect») avec ses algorithmes, interfaces et techniques d’interaction, qui a été développée pour aider à détecter l’hémolyse qui représente une rupture des globules rouges (érythrocytes) et la libération de leur contenu (cytoplasme) dans le liquide environnant (par exemple, le plasma sanguin), en le complétant par des statistiques de laboratoire et des mesures montrant son utilisation au cours des expériences, ce qui pourrait finalement être un concept réalisable qui pourrait permettre une détection précoce de l'hémolyse

Design og styring av smarte robotsystemer for applikasjoner innen biovitenskap: biologisk prøvetaking og jordbærhøsting

This thesis aims to contribute knowledge to support fully automation in life-science applications, which includes design, development, control and integration of robotic systems for sample preparation and strawberry harvesting, and is divided into two parts. Part I shows the development of robotic systems for the preparation of fungal samples for Fourier transform infrared (FTIR) spectroscopy. The first step in this part developed a fully automated robot for homogenization of fungal samples using ultrasonication. The platform was constructed with a modified inexpensive 3D printer, equipped with a camera to distinguish sample wells and blank wells. Machine vision was also used to quantify the fungi homogenization process using model fitting, suggesting that homogeneity level to ultrasonication time can be well fitted with exponential decay equations. Moreover, a feedback control strategy was proposed that used the standard deviation of local homogeneity values to determine the ultrasonication termination time. The second step extended the first step to develop a fully automated robot for the whole process preparation of fungal samples for FTIR spectroscopy by adding a newly designed centrifuge and liquid-handling module for sample washing, concentration and spotting. The new system used machine vision with deep learning to identify the labware settings, which frees the users from inputting the labware information manually. Part II of the thesis deals with robotic strawberry harvesting. This part can be further divided into three stages. i) The first stage designed a novel cable-driven gripper with sensing capabilities, which has high tolerance to positional errors and can reduce picking time with a storage container. The gripper uses fingers to form a closed space that can open to capture a fruit and close to push the stem to the cutting area. Equipped with internal sensors, the gripper is able to control a robotic arm to correct for positional errors introduced by the vision system, improving the robustness. The gripper and a detection method based on color thresholding were integrated into a complete system for strawberry harvesting. ii) The second stage introduced the improvements and updates to the first stage where the main focus was to address the challenges in unstructured environment by introducing a light-adaptive color thresholding method for vision and a novel obstacle-separation algorithm for manipulation. At this stage, the new fully integrated strawberry-harvesting system with dual-manipulator was capable of picking strawberries continuously in polytunnels. The main scientific contribution of this stage is the novel obstacle-separation path-planning algorithm, which is fundamentally different from traditional path planning where obstacles are typically avoided. The algorithm uses the gripper to push aside surrounding obstacles from an entrance, thus clearing the way for it to swallow the target strawberry. Improvements were also made to the gripper, the arm, and the control. iii) The third stage improved the obstacle-separation method by introducing a zig-zag push for both horizontal and upward directions and a novel dragging operation to separate upper obstacles from the target. The zig-zag push can help the gripper capture a target since the generated shaking motion can break the static contact force between the target and obstacles. The dragging operation is able to address the issue of mis-capturing obstacles located above the target, in which the gripper drags the target to a place with fewer obstacles and then pushes back to move the obstacles aside for further detachment. The separation paths are determined by the number and distribution of obstacles based on the downsampled point cloud in the region of interest.Denne avhandlingen tar sikte på å bidra med kunnskap om automatisering og robotisering av applikasjoner innen livsvitenskap. Avhandlingen er todelt, og tar for seg design, utvikling, styring og integrering av robotsystemer for prøvetaking og jordbærhøsting. Del I omhandler utvikling av robotsystemer til bruk under forberedelse av sopprøver for Fourier-transform infrarød (FTIR) spektroskopi. I første stadium av denne delen ble det utviklet en helautomatisert robot for homogenisering av sopprøver ved bruk av ultralyd-sonikering. Plattformen ble konstruert ved å modifisere en billig 3D-printer og utstyre den med et kamera for å kunne skille prøvebrønner fra kontrollbrønner. Maskinsyn ble også tatt i bruk for å estimere soppens homogeniseringsprosess ved hjelp av matematisk modellering, noe som viste at homogenitetsnivået faller eksponensielt med tiden. Videre ble det foreslått en strategi for regulering i lukker sløyfe som brukte standardavviket for lokale homogenitetsverdier til å bestemme avslutningstidspunkt for sonikeringen. I neste stadium ble den første plattformen videreutviklet til en helautomatisert robot for hele prosessen som forbereder prøver av sopprøver for FTIR-spektroskopi. Dette ble gjort ved å legge til en nyutviklet sentrifuge- og væskehåndteringsmodul for vasking, konsentrering og spotting av prøver. Det nye systemet brukte maskinsyn med dyp læring for å identifisere innstillingene for laboratorieutstyr, noe som gjør at brukerne slipper å registrere innstillingene manuelt.Norwegian University of Life SciencespublishedVersio

Physiological and vascular responses to acute and chronic exercise in men and women with cardiovascular disease

Study 1: Brachial artery flow-mediated dilation (FMD) using ultrasonography is used as a surrogate measure of coronary artery function. The purpose of this study was to i) assess the reliability of the PhD student in the use of ultrasonography to measure endothelial vasomotor function, and ii) develop and validate a custom-designed software to measure arterial diameter. The sonographer demonstrated excellent reliability in FMD assessment. Compared to in-built ultrasound calipers, the custom-designed software was shown to be a valid measure of arterial diameter. Study 2: This study evaluated the physiological and vascular responses to self-regulated exercise (SRE) and high-intensity interval training (HIIT) in individuals with cardiovascular disease. Physiological and perceptual responses were significantly higher in response to HIIT than SRE. There was no change in FMD in either group following exercise. Study 3: This study compared the effects of 4 weeks of traditional cardiac rehabilitation and 4 weeks of HIIT on the physiological and perceptual responses, endothelial function, and blood lipids in individuals with CVD. Treadmill time to exhaustion and percentage change in FMD were significantly higher in the HIIT group at week 4 than week 1

OpenSim-Based Musculoskeletal Modeling: Foundation for Interactive Obstetric Simulator

The use of mathematical and computational models to understand complex biological systems, such as the human birth process, is a rapidly growing field in medicine. These models can be used to optimize and personalize medical treatments for individual patients, enhance training, and aid in educational efforts. While recent advancements in healthcare, particularly in obstetrics, have improved care for mothers and babies, studies and government reports indicate a rising rate of maternal mortality in the United States. Despite this rising trend, there is a lack of detailed studies concerning the use of modeling and simulation to develop an interactive obstetrics simulator that can aid both practitioners and patients. This research builds upon a novel template for developing an interactive obstetric simulator and aims to replicate an onerous finite element vaginal delivery simulation with an interactive, patient-specific simulator that emphasizes musculoskeletal dynamics. The study utilizes the open-source platform of OpenSim and inverse-kinematic solutions to develop fetal and maternal musculoskeletal models and simulate birth on the musculoskeletal level