CONTROL OF RADIATION EXPOSURE TO PAEDIATRIC PATIENTS AT CONVENTIONAL RADIOLOGY AND CARDIAC CENTERS AT DUBAI HOSPITAL

In view of increasing the number of x-ray examinations over the years, paediatric radiation safety is considered as one of the critical subjects in the modern medical imaging. Paediatric patients are at higher risk from ionizing radiation than adults if they receive same amount of dose. This project was conducted to evaluate paediatric patient radiation dose levels in digital radiology (both fixed and mobile x-ray units) and interventional cardiology at Dubai Hospital. The results of this study are expected to contribute in establishing local and national diagnostic reference levels in United Arab Emirates (UAE). A combination of phantom studies and patient data collection were utilized in this paediatric dosimetry project. The patient data collection was obtained through both manual contributions from radiographers and data obtained from Digital Imaging and Communications in Medicine (DICOM) header. The first method was performed using Polymethyl methacrylate phantom with different thicknesses to represent different age groups of paediatrics; whereas the second method was without phantom where the exposure factors extracted from DICOM header. Then, effective dose was estimated using Monte Carlo dose calculation software. The primary measured and estimated radiation dose quantity was the incident air kerma. The entrance surface air kerma was calculated from the incident air kerma and then executed with the application of appropriate backscatter factors. For the fixed x-ray machine, the radiation dose levels were lower than the recommended values and other published data while for the mobile x-ray the findings were comparable and slightly higher than other surveyors. In interventional cardiology, the radiation dose values were higher compared to other values shown in previous researches. The variation in entrance skin air kerma values between the published data and the findings in this study are related to the use of different equipment, exposure parameters and it is significantly related to the professional awareness towards ionizing radiation hazards. Evidently, the values of effective doses showed that the radiation risk is higher with small ages. In UAE, this study is considered as one of the first structured studies performed on paediatric dosimetry. Further researches are needed to include image viii quality assessment to stress on obtaining optimum image quality with lower radiation dose

CONTROL OF RADIATION EXPOSURE TO PAEDIATRIC PATIENTS AT CONVENTIONAL RADIOLOGY AND CARDIAC CENTERS AT DUBAI HOSPITAL

In view of increasing the number of x-ray examinations over the years, paediatric radiation safety is considered as one of the critical subjects in the modern medical imaging. Paediatric patients are at higher risk from ionizing radiation than adults if they receive same amount of dose. This project was conducted to evaluate paediatric patient radiation dose levels in digital radiology (both fixed and mobile x-ray units) and interventional cardiology at Dubai Hospital. The results of this study are expected to contribute in establishing local and national diagnostic reference levels in United Arab Emirates (UAE). A combination of phantom studies and patient data collection were utilized in this paediatric dosimetry project. The patient data collection was obtained through both manual contributions from radiographers and data obtained from Digital Imaging and Communications in Medicine (DICOM) header. The first method was performed using Polymethyl methacrylate phantom with different thicknesses to represent different age groups of paediatrics; whereas the second method was without phantom where the exposure factors extracted from DICOM header. Then, effective dose was estimated using Monte Carlo dose calculation software. The primary measured and estimated radiation dose quantity was the incident air kerma. The entrance surface air kerma was calculated from the incident air kerma and then executed with the application of appropriate backscatter factors. For the fixed x-ray machine, the radiation dose levels were lower than the recommended values and other published data while for the mobile x-ray the findings were comparable and slightly higher than other surveyors. In interventional cardiology, the radiation dose values were higher compared to other values shown in previous researches. The variation in entrance skin air kerma values between the published data and the findings in this study are related to the use of different equipment, exposure parameters and it is significantly related to the professional awareness towards ionizing radiation hazards. Evidently, the values of effective doses showed that the radiation risk is higher with small ages. In UAE, this study is considered as one of the first structured studies performed on paediatric dosimetry. Further researches are needed to include image viii quality assessment to stress on obtaining optimum image quality with lower radiation dose

Modelo de informatização de uma unidade de tratamento intensivo neonatal

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico.Programa de Pós-Graduação em Ciência da ComputaçãoEste trabalho descreve uma tecnologia de software desenvolvida para apoiar o acompanhamento clinico de recém-nascidos em uma UTI Neonatal, onde pode ajudar, o pessoal médico, de enfermagem e farmácia envolvidos diretamente ao tratamento destes bebês. Com o objetivo de ter o formato de um PEP (Prontuário Eletrônico de Paciente) e armazenar informações dos pacientes em um padrão internacional (DICOM SR), foi desenvolvido uma ferramenta que, efetivamente, diminui um tempo considerável na execução das tarefas deste setor e minimiza o erro em situações de alto risco para os recém-nascidos (RN). Impactando, indiretamente, na melhoria da qualidade do atendimento da UTI, já que os médicos passam a ter mais tempo para o acompanhamento clínico. Uma das principais características do Cyclops Neonatal Intensive Care Unit é o cálculo de nutrição parenteral, que representa uma das primeiras formas de alimentação para os RN internados. Este projeto foi implantado na Maternidade Carmela Dutra, de Florianópolis, e foi validado por mais de 18 meses, tendo um impacto bastante positivo

Innovative ICT solutions in telemedicine to support clinical practice and research in hospitals

2010/2011The scope of this study was to examine ICT telemedicine innovations and potentialities in web-portals, intranet services and tele-radiology topics respectively, in order to design, develop and, possibly, realize apposite telemedicine systems and solutions for healthcare and in particular for the hospitals. ICT techniques and technologies are nowadays applied in every area of our common living from work places to our homes, our free-time, schools, universities and so on. The healthcare services offered by hospitals are heavily supported by technologies and, behind them, by a wide research both in ICT and biomedical sciences. Thanks to these advances telemedicine is now becoming a fundamental part of services offered by hospitals and healthcare structures. The healthcare management, the doctors and the common people are now experimenting how telemedicine is an added value to all the services offered in terms of the quality of care, the patient follow up, the early diagnose and treatment of pathologies and diseases. In this research is presented an all-inclusive approach to telemedicine problems and challenges in particular studying, developing and proposing ICT methods and technologies in the above mentioned three areas of interest: •innovative healthcare and telemedicine-ready hospital website or portal design and development; •analysis and study of models for the realization of intranet healthcare services to enhance both quality of care and the management of healthcare personnel evaluation; •tele-radiology and some of its actual new perspectives as the study and the evaluation of the “mobile” tele-radiology approach using commercial tablets (and what it could mean).For the first topic the results may be summarized in the development of a more interactive and “social” hospital web-portal offering original solutions and services to all the categories of users (audience, professionals, researchers), allowing them – through the use of advanced tools - to configure and select their own pages and interests. The originality of this approach consists in a good cost/effective result in the respect of the last and worldwide accepted Internet regulations and policies too. A similar approach regarded the intranet services and the design of web interfaces for the clinical practice and the executive evaluation. These kind of innovative systems regard a limited and selected number of more skilled users, typically belonging to a corporation or to specific offices. As above the approach is important: interactive services, innovative tools and affordable instruments are the keywords of the systems designed or proposed to solve specific problems or needs. The last research topic concerned the proposal of a protocol for the assessment of medical images on commercial displays, interesting the stakeholders and the groups involved in medical images treatment, visualization and communication. The potentialities of the mobile tablet devices improve day after day and new devices are marketed every week and the innovation is round the corner. These potentialities must encounter the medical diagnostics world and meet the standards and the regulations the international community established. It will be difficult for a commercial tablet to obtain the medical device CE mark not only for commercial reasons, but the technical limits may be reached and even surpassed adopting objective measures and evaluations. This study demonstrates that commercial tablets may be used in clinical practice for the correct visualization and diagnose of medical images. The measures of some display characteristics may be considered acceptable for mobile interpretation (even report?) of medical images, but if and only if the ambient lighting conditions are under objective control and integrated automated systems in tablets warns physicians about bad or borderline technical and ambient restrictions or bonds.XXIII Ciclo197

Arquiteturas federadas para integração de dados biomédicos

Doutoramento Ciências da ComputaçãoThe last decades have been characterized by a continuous adoption of IT solutions in the healthcare sector, which resulted in the proliferation of tremendous amounts of data over heterogeneous systems. Distinct data types are currently generated, manipulated, and stored, in the several institutions where patients are treated. The data sharing and an integrated access to this information will allow extracting relevant knowledge that can lead to better diagnostics and treatments. This thesis proposes new integration models for gathering information and extracting knowledge from multiple and heterogeneous biomedical sources. The scenario complexity led us to split the integration problem according to the data type and to the usage specificity. The first contribution is a cloud-based architecture for exchanging medical imaging services. It offers a simplified registration mechanism for providers and services, promotes remote data access, and facilitates the integration of distributed data sources. Moreover, it is compliant with international standards, ensuring the platform interoperability with current medical imaging devices. The second proposal is a sensor-based architecture for integration of electronic health records. It follows a federated integration model and aims to provide a scalable solution to search and retrieve data from multiple information systems. The last contribution is an open architecture for gathering patient-level data from disperse and heterogeneous databases. All the proposed solutions were deployed and validated in real world use cases.A adoção sucessiva das tecnologias de comunicação e de informação na área da saúde tem permitido um aumento na diversidade e na qualidade dos serviços prestados, mas, ao mesmo tempo, tem gerado uma enorme quantidade de dados, cujo valor científico está ainda por explorar. A partilha e o acesso integrado a esta informação poderá permitir a identificação de novas descobertas que possam conduzir a melhores diagnósticos e a melhores tratamentos clínicos. Esta tese propõe novos modelos de integração e de exploração de dados com vista à extração de conhecimento biomédico a partir de múltiplas fontes de dados. A primeira contribuição é uma arquitetura baseada em nuvem para partilha de serviços de imagem médica. Esta solução oferece um mecanismo de registo simplificado para fornecedores e serviços, permitindo o acesso remoto e facilitando a integração de diferentes fontes de dados. A segunda proposta é uma arquitetura baseada em sensores para integração de registos electrónicos de pacientes. Esta estratégia segue um modelo de integração federado e tem como objetivo fornecer uma solução escalável que permita a pesquisa em múltiplos sistemas de informação. Finalmente, o terceiro contributo é um sistema aberto para disponibilizar dados de pacientes num contexto europeu. Todas as soluções foram implementadas e validadas em cenários reais

Pulmonary Gas Transport and Drug Delivery in a Patient Specific Lung Model During Invasive High Frequency Oscillatory Ventilation

The objective of this dissertation research was to investigate gas transport, mixing and aerosol-drug delivery during high frequency oscillatory ventilation (HFOV) for various ventilator specific conditions that are vital to critical care clinicians. A large eddy simulation based computational fluid dynamics approach was used in a patient specific human lung model to analyze the effect of invasive HFOV on patient management. Different HFOV waveform shapes and frequencies was investigated and the square waveform was found to be most efficient for gas mixing; resulting in the least wall shear stress on the lung epithelium layer thereby reducing the risk of barotrauma to both airways and the alveoli for patients undergoing therapy. Traditional (outlet) boundary conditions based on mass fraction or outlet pressures were found to be inadequate in describing the complex flow physics that occurs during HFOV. Physiological boundary conditions that used the time-dependent pressure coupled with the airways resistance and compliance (R&C) were derived and used for the first time to investigate the lung lobar ventilation and gas exchange for accurate HFOV modeling. A Lagrangian approach was then used to model gas-solid two-phase flow that allowed investigation of the potential of aerosol-drug delivery under HFOV treatment. We report, for the first time, computational fluid dynamics studies to investigate the possibilities of aerosol drug delivery under HFOV. Understanding the role of different carrier gases on the gas exchange and particle deposition, which may allow for optimum drug delivery and ventilation strategy during HFOV. Increasing the operating frequency resulted in a significant change in the global and local deposition indicating strong dependency on the frequency, which could be beneficial for the targeted drug delivery. The global deposition as a fraction of the total injected particles at the endotracheal tube inlet was equivalent to the cases of normal breathing and conventional mechanical ventilation signifying a potential for efficient drug delivery during HFOV. In addition, HFOV had a unique characterization of the local particle deposition due to the rapid ventilation process and a strong influence of the endotracheal tube jet. Very often during ventilation therapy, a clinician uses a cocktail of various gases to enhance targeted therapy. To quantify this process for a futuristic HFOV based patient management, we undertook detailed studies to understand the role of carrier gas properties in gas exchange and particle transport during HFOV. A substantial amplification of the pendelluft flow was achieved by utilizing a low-density carrier gas instead of air, which resulted in gas exchange improvement. Reducing the carrier gas density was found to significantly alter the aerosol-drug delivery under HFOV management. As the density decreased, the deposition fraction in the upper tracheobronchial tree decreased, indicating enhancement of the lung periphery delivery. Furthermore, the filtered aerosol-drug in the ventilator circuit could be significantly reduced by using Heliox, and further reduction could be achieved by reducing the operating frequency. In general, high-frequency oscillatory ventilation therapy could be improved under Heliox with greater content of Helium, thereby reducing the lung hyperinflation risk

A standards-based ICT framework to enable a service-oriented approach to clinical decision support

This research provides evidence that standards based Clinical Decision Support (CDS) at the point of care is an essential ingredient of electronic healthcare service delivery. A Service Oriented Architecture (SOA) based solution is explored, that serves as a task management system to coordinate complex distributed and disparate IT systems, processes and resources (human and computer) to provide standards based CDS. This research offers a solution to the challenges in implementing computerised CDS such as integration with heterogeneous legacy systems. Reuse of components and services to reduce costs and save time. The benefits of a sharable CDS service that can be reused by different healthcare practitioners to provide collaborative patient care is demonstrated. This solution provides orchestration among different services by extracting data from sources like patient databases, clinical knowledge bases and evidence-based clinical guidelines (CGs) in order to facilitate multiple CDS requests coming from different healthcare settings. This architecture aims to aid users at different levels of Healthcare Delivery Organizations (HCOs) to maintain a CDS repository, along with monitoring and managing services, thus enabling transparency. The research employs the Design Science research methodology (DSRM) combined with The Open Group Architecture Framework (TOGAF), an open source group initiative for Enterprise Architecture Framework (EAF). DSRM’s iterative capability addresses the rapidly evolving nature of workflows in healthcare. This SOA based solution uses standards-based open source technologies and platforms, the latest healthcare standards by HL7 and OMG, Decision Support Service (DSS) and Retrieve, Update Locate Service (RLUS) standard. Combining business process management (BPM) technologies, business rules with SOA ensures the HCO’s capability to manage its processes. This architectural solution is evaluated by successfully implementing evidence based CGs at the point of care in areas such as; a) Diagnostics (Chronic Obstructive Disease), b) Urgent Referral (Lung Cancer), c) Genome testing and integration with CDS in screening (Lynch’s syndrome). In addition to medical care, the CDS solution can benefit organizational processes for collaborative care delivery by connecting patients, physicians and other associated members. This framework facilitates integration of different types of CDS ideal for the different healthcare processes, enabling sharable CDS capabilities within and across organizations

Phantom and computational studies towards the clinical translation of gas in scattering media absorption spectroscopy into neonatal respiratory care

Everything except vacuum is heterogeneous to some extent. Even media that we consider homogeneous (such as pure gases and water) can be taken apart into individual heterogeneities (such as atoms and molecules), which can be distinguished with a sufficiently fine probe. Absorption spectroscopy was extensively used by Robert Bunsen and Gustav Kirchhoff in the 1860’s to separate, identify and measure various chemical substances. They defined a line of research, where traces of elements were just detectable with the aid of specialized instruments like the spectroscope, and since then, the absorption lines have been subject of experimental and theoretical developments. Today, we know that the nature of the absorption lines can be described by quantum mechanical changes induced in the atoms or molecules, and with the advances in light sources and sensing technologies, absorption spectroscopy has become a tremendously useful tool with a wide range of applications. The studies presented in this thesis are related to gas absorption spectroscopy, in particular, a technique called GASMAS, which stands for “GAs in Scattering Media Absorption Spectroscopy”. This spectroscopy technique was introduced in Lund University in 2001 by S. Svanberg’s group, to study the spectral features of gases inside porous or hollowed scattering media, combining laser spectroscopy with sensitive modulation techniques. Unlike solids and liquids, which have a smooth absorption and scattering wavelength dependence (1 − 10 nm), gases exhibit sharp absorptive features (10−4 nm). This difference between the absorption spectra of solid state matter and gases, is the corner stone of this technique. In a typical GASMAS measurement, the laser wavelength is scanned across at least one of the absorption lines of the gas of interest. The small gas absorption signal (embedded in the scattered spectrum from the bulk material) is then filtered from the detected signal, making it possible to retrieve the gas concentrations and study their diffusion dynamics using the principles of the Beer-Lambert law. Although there is evidence of the potential of GASMAS to sense oxygen and water vapor in human cavities, such as the ear, nasal sinuses, lungs, intestines and hip bone, one the most promising clinical applications could be the lung function assessment in neonates. The focus of this thesis is to investigate the potential of translating GASMAS into such an application, combining a computational and experimental approach. Most of the work was done in a collaboration between Biophotonics@Tyndall, the Infant Centre (hosted at the Cork University Maternity Hospital-UCC) and the Swedish industry partner, GPX Medical who have built a pioneering GASMAS instrument, suitable for clinical use. The motivation behind this collaborative work, is to assist clinicians in the monitoring of lung function in premature newborns, as their lungs lack structural and biochemical maturation, which can result in respiratory failure. Currently, the use of GASMAS is limited to observational studies with healthy babies. Thus, the improvement and optimization of the technology depends on feasibility tests with tissue-like models. Phantoms mimicking the geometry and optical properties of the main thoracic organs, were created to study the influence of source detector positioning and chest physiognomy in the GASMAS signals. A functional phantom resembling the anatomy, temperature and humidity of the respiratory zone, was also developed to investigate the potential of GASMAS technique in measuring changes in inflated volume. The optimization of source-detector configurations over the thorax is one of the challenges in the clinical translation of GASMAS. It is crucial to define the optimal probe positioning, to obtain the highest possible signal reaching the detector, which also carries information of the gas absorption in lung tissue. Computational studies are then used to simulate the light transport in accurate anthropomorphic models, which contributes with the understanding of near infra-red interaction with the thorax, and most of all, to find the probe locations for which the detection of gas absorption is feasible, and enhance the data acquisition in future clinical studies. This document includes the theoretical background of GASMAS, the basics of respiratory physiology, and the current methods for clinical monitoring and diagnostics of lung pathologies in neonates. The following two chapters, show how the developed phantom and computational models enable the recreation of different clinical scenarios, suitable for GASMAS studies. The main contribute is the identification of the minimum requirements necessary to further improve and advance towards a GASMAS bedside clinical device, that can potentially be used, for lung function assessment and monitoring in neonatal respiratory health