KTH, Division of Neuronic Engineering, have a finite element model of the head. However, this model does not contain detailed modeling of the brain. This thesis project consists of finding a method to extract brain tissues from T1-weighted MR images of the head. The method should be automatic to be suitable for patient individual modeling. A summary of the most common segmentation methods is presented and one of the methods is implemented. The implemented method is based on the assumption that the probability density function (pdf) of an MR image can be described by parametric models. The intensity distribution of each tissue class is modeled as a Gaussian distribution. Thus, the total pdf is a sum of Gaussians. However, the voxel values are also influenced by intensity inhomogeneities, which affect the pdf. The implemented method is based on the expectation-maximization algorithm and it corrects for intensity inhomogeneities. The result from the algorithm is a classification of the voxels. The brain is extracted from the classified voxels using morphological operations.

Technologies in image acquisition have developed and often provide image volumes in more than two dimensions. Computer tomography and magnet resonance imaging provide image volumes in three spatial dimensions. The image enhancement methods have developed as well and in this thesis work 3D image enhancement with filter networks is evaluated. The aims of this work are; to find a method which makes the initial parameter settings in the 3D image enhancement processing easier, to compare 2D and 3D processed image volumes visualized with different visualization techniques and to give an illustration of the benefits with 3D image enhancement processing visualized using these techniques. The results of this work are; 1. a parameter setting tool that makes the initial parameter setting much easier and 2. an evaluation of 3D image enhancement with filter networks that shows a significant enhanced image quality in 3D processed image volumes with a high noise level compared to the 2D processed volumes. These results are shown in slices, MIP and volume rendering. The differences are even more pronounced if the volume is presented in a different projection than the volume is 2D processed in.

I hälso- och sjukvården i Sverige används ett flertal medicintekniska apparater och IT-system. Ofta läser man av en skärm på den medicintekniska apparaten och noterar informationen på papper för att sedan manuellt mata in dessa uppgifter i IT-systemen. Detta manuella mellanled finns det önskemål och förhoppningar om att slippa. Man vill kunna överföra information automatiskt mellan den medicintekniska apparaten och IT-systemet, med andra ord vill man integrera dem. För att åstadkomma detta måste ett antal grund-läggande förutsättningar uppfyllas. Bland annat ställs vissa krav på tekniken hos den medicintekniska apparaten, kommunikationskanalen och IT-systemet. Dessutom är det nödvändigt att uppfylla gällande lagar och regler. Utöver detta finns det faktorer som kan underlätta, till exempel användandet av erkända standarder för kommunikationen. Syftet med detta examensarbete har varit att belysa och utreda dessa bakomliggande faktorer för att få integration av nyss beskrivet slag att fungera. Arbetet är en bakgrundsstudie på detta område.

I dagens samhälle är det vanligt att patienter söker vård hos olika vårdgivare, vilket resulterar i att vårdinformationen blir splittrad och allt högre krav ställs på de datoriserade journalsystemen. Till exempel ska de stödja ett processorienterat arbetssätt för att samla information från samma vårdprocess. Vårdinformationen måste därför vara tillgänglig över organisationsgränser och olika journalsystem måste kunna kommunicera med varandra, där en ökad tillgänglighet ställer högre krav på informationssäkerhet och behörighetskontroll. Journalsystemen bör, för att uppfylla dessa krav, utvecklas enligt standarder och riktlinjer. Det finns ett flertal nationella och internationella organisationer som arbetar med att ta fram standarder och riktlinjer för hur journalsystem bör utvecklas. Problemet är att dessa arbeten sker på olika nivåer och gäller olika delar av journalsystemen. Det är därmed en stor utmaning för journalleverantörer att förhålla sig till dessa arbeten. Syftet med det här examensarbetet har varit att utreda hur utvalda, svenska och europeiska, standardiseringsarbeten förhåller sig till varandra samt att avgöra på vilket sätt de är av relevans för journalleverantörer. Dessutom har syftet varit att framställa en prototyp av ett IT-stöd för processorienterad vårddokumentation. En kvalitativ litteraturstudie har i det här examensarbetet resulterat i en sammanställning av de utvalda standardiseringsarbetena. Arbetena hanterar främst områden som kan användas för att ena vårdprocessen, exempel på dessa är behörighetskontroll och standardiserad kommunikation med informationsspecifikationer eller arketyper. SAMBA har tagit fram en processmodell som beskriver vårdprocessen. Baserat på denna modell och krav från standardiseringsarbetena har vi framställt ett förslag på ett IT-stöd för processorienterad vårddokumentation.

Technology of today makes it possible to change the way traditional healthcare is conducted. As the population grows older, and the elderly is becoming an increasing part of the whole population, the need for cost efficient and personalised care increases. By implementing home healthcare IT projects, it is possible for more patients to be treated at home with sustained quality of care. This thesis documents the work of a master’s degree project carried out during the autumn of 2005. The project is part of a research project within the Department of Biomedical Engineering at Linköping University. The project aims at developing a data model for storing medical data. The model should be general and easy to expand. This model is intended to be used within a larger system allowing a patient to measure medical data from a remote location.

Today Image acquisition equipment produces huge amounts of data that needs to be processed. Often the data describes signals with a dimensionality higher then 2, as with ordinary images. This introduce a problem when it comes to process this high dimensional data since ordinary signal processing tools are no longer suitable. New faster and more efficient tools need to be developed to fully exploit the advantages with e. g. a 3D CT-scan. One such tool is filternets, a layered networklike structure, which the signal propagates through. A filternet has three fundamental advantages which will decrease the filtering time. The network structure allows complex filter to be decomposed into simpler ones, intermediate result may be reused and filters may be implemented with very few nonzero coefficients (sparse filters). The aim of this study has been to create an implementation for filternets and optimize it with respect to execution time. Specially the possibility to use filternets that approximates a harmonic filterset for estimating orientation in 3D signals is investigated. Tests show that this method is up to about 30 times faster than a full filterset consisting of dense filters. They also show a slightly larger error in the estimated orientation compared with the dense filters, this error should however not limit the usability of the method.

<p>I hälso- och sjukvården i Sverige används ett flertal medicintekniska apparater och IT-system. Ofta läser man av en skärm på den medicintekniska apparaten och noterar informationen på papper för att sedan manuellt mata in dessa uppgifter i IT-systemen. Detta manuella mellanled finns det önskemål och förhoppningar om att slippa. Man vill kunna överföra information automatiskt mellan den medicintekniska apparaten och IT-systemet, med andra ord vill man integrera dem. För att åstadkomma detta måste ett antal grund-läggande förutsättningar uppfyllas. Bland annat ställs vissa krav på tekniken hos den medicintekniska apparaten, kommunikationskanalen och IT-systemet. Dessutom är det nödvändigt att uppfylla gällande lagar och regler. Utöver detta finns det faktorer som kan underlätta, till exempel användandet av erkända standarder för kommunikationen. Syftet med detta examensarbete har varit att belysa och utreda dessa bakomliggande faktorer för att få integration av nyss beskrivet slag att fungera. Arbetet är en bakgrundsstudie på detta område.</p>

<p>In this thesis, a very flexible framework for simulating RIS is designed to beused for Infobroker testing. Infobroker is an application developed by MawellSvenska AB that connects RIS and PACS to achieve interoperability by enablingimage and journal data transmission between radiology sites. To put the project in context, the field of medical informatics, RIS and PACS systems and common protocols and standards are explored. A proof-of-concept implementation of the proposed design shows its potential and verifies that it works. The thesis concludes that a more specialized approach is preferred.</p>

In the light of an ageing society with shrinking economic resources, deinstitutionalization of elderly care is a general trend. As a result, homecare is increasing, and increasingly shared between different health and social care organizations. To provide a holistic overview about the patient care process, i.e. to be patient-centred, shared homecare needs to be integrated. This requires improved support for information sharing and cooperation between different actors, such as care professionals, patients and their relatives. The research objectives of this thesis are therefore to study information and communication needs for patient-centered shared homecare, to explore how integrated information and communication technology (ICT) can support information sharing, and to analyze how current standards for continuity of care and semantic interoperability meet requirements of patient-centered shared homecare. An action research approach, characterized by an iterative cycle, an emphasis on change and close collaboration with practitioners, patients and their relatives, was used. Studying one specific homecare setting closely, intersection points between involved actors and specific needs for information sharing were identified and described as shared information objects. An integration architecture making shared information objects available through integration of existing systems was designed and implemented. Mobile virtual health record (VHR) applications thereby enable a seamless flow of information between involved actors. These applications were tested and validated in the OLD@HOME-project. Moreover, the underlying information model for a shared care plan was mapped against current standards. Some important discrepancies were identified between these results and current standards for continuity of care, stressing the importance of evaluating standardized models against requirements of evolving healthcare contexts. In conclusion, this thesis gives important insights into the needs and requirements of shared homecare, enabling a shift towards patient-centered homecare through mobile access to aggregated information from current feeder systems and documentation at the point of need.

Magnetic resonance imaging (MRI) is a very versatile imaging modality which can be used to acquire several different types of images. Some examples include anatomical images, images showing local brain activation and images depicting different types of pathologies. Brain activation is detected by means of functional magnetic resonance imaging (fMRI). This is useful e.g. in planning of neurosurgical procedures and in neurological research. To find the activated regions, a sequence of images of the brain is collected while a patient or subject alters between resting and performing a task. The variations in image intensity over time are then compared to a model of the variations expected to be found in active parts of the brain. Locations with high correlation between the intensity variations and the model are considered to be activated by the task. Since the images are very noisy, spatial filtering is needed before the activation can be detected. If adaptive filtering is used, i.e. if the filter at each location is adapted to the local neighborhood, very good detection performance can be obtained. This thesis presents two methods for adaptive spatial filtering of fMRI data. One of these is a modification of a previously proposed method, which at each position maximizes the similarity between the filter response and the model. A novel feature of the presented method is rotational invariance, i.e. equal sensitivity to activated regions in different orientations. The other method is based on bilateral filtering. At each position, this method averages pixels which are located in the same type of brain tissue and have similar intensity variation over time. A method for robust correlation estimation is also presented. This method automatically detects local bursts of noise in a signal and disregards the corresponding signal segments when the correlation is estimated. Hence, the correlation estimate is not affected by the noise bursts. This method is useful not only in analysis of fMRI data, but also in other applications where correlation is used to determine the similarity between signals. Finally, a method for correcting artifacts in complex MR images is presented. Complex images are used e.g. in the Dixon technique for separate imaging of water and fat. The phase of these images is often affected by artifacts and therefore need correction before the actual water and fat images can be calculated. The presented method for phase correction is based on an image integration technique known as the inverse gradient. The method is shown to provide good results even when applied to images with severe artifacts.