Identifiering av bisköldkörtlar är viktigt vid sköldkörtel- och bisköldkörtelkirurgi och kan vara svårt då de liknar omgivande vävnad såsom fett och lymfkörtlar. Peroperativ detektering av dessa vävnader kan förbättra möjligheten att bota patienter med hyperparathyroidism och minska risken för bisköldkörtelskador vid thyroideakirurgi. Optiska metoder är potentiella tekniker för att möjliggöra detta. Optiska tekniker utvärderades på vävnadsprover från patienter vid bisköldkörtel- och sköldkörteloperation. Teknikerna bestod av nära infraröd fluorescens (NIR) spektroskopi och optisk koherenstomografi (OCT) som ger en bild av vävnadens mikrostruktur liknande till ultraljud med högre upplösning (10 μm).

Resection of brain tumor is a challenging task as the tumor does not have clear borders and the malignant types specifically have often a diffuse and infiltrative pattern of growth. Recently, neurosurgical microscopes have been modified to incorporate fluorescence modules for detection of tumor when 5-aminolevulinic acid (5-ALA) is used as a contrast. We have in combination with the fluorescence microscopes implemented and evaluated a fluorescence spectroscopy based handheld probe for detecting the 5-aminolevulinic acid (ALA) induced protoporphyrin IX (PpIX) in the gliomas in 50 patients intraoperatively. The results show a significantly high sensitivity for differentiating tumor from the healthy tissue and distinguished fluorescence intensity levels in the tumor cell infiltration zone around the tumor. However, knowledge on association of the quantified fluorescence signals specifically in the intermediate inflammatory zone with the infiltrative tumor cells can be complemented with volumetric tissue imaging and a higher precision histopathological analysis. In this work, a spectral domain optical coherence tomography (OCT) system with central wavelength of 1325nm has been used to image the tissue volume that the fluorescence is collected from and is evaluated against histopathological analysis for a higher precision slicing. The results show that although healthy brain has a homogenous microstructure in the OCT images, the brain tumor shows a distinguished texture in the images correlated with the PpIX fluorescence intensity and histopathology.

Resection of brain tumor is a challenging task as the tumor does not have clear borders and the malignant types specifically have often a diffuse and infiltrative pattern of growth. We have previously implemented and evaluated a fluorescence spectroscopy based handheld probe for detecting the 5-aminolevulinic acid induced protoporphyrin IX (PpIX) in the gliomas. To add another dimension to the brain tumor detection and volumetric analysis of the tissue that exhibits fluorescence, optical coherence tomography was investigated on tumor specimens.

Material and Methods:

A fluorescence microscopy and a spectroscopy system as reported previously were used for detecting the fluorescence signals [1, 2]. A total of 50 patients have been included for intraoperative assessment of the tumor borders using the fluorescence techniques. A spectral domain OCT imaging system (TELESTO II, Thorlabs, Inc., NJ, USA) with central wavelength of 1325 nm was used to study the tissue microstructure post operatively. The system has a resolution of 13 and 5.5 μm in the lateral and axial directions, respectively. Tissue specimens from three patients undergoing brain tumor surgery were studied using the OCT system.

Results and Conclusion:

Using fluorescence spectroscopy the tumor could be detected with a sensitivity of 0.84 which was significantly higher than that of the surgical microscope (0.30). Brain tissue appeared rather homogeneous in the OCT images however the highly malignant tissue showed a clear structural difference from the non-malignant or low malignant brain tumor tissue which could be related to the fluorescence signal intensities.

To provide guidance for targeting diagnostic tumor tissue and to avoid vessel rupture during the biopsy procedure an application specific fiber optic probe was devel-oped. The setup incorporated an in-house developed fluorescence spectroscopy system for 5-aminolevulinic acid (5-ALA) induced protopophyrin IX (PpIX) for detection in the tumor, and laser Doppler flowmeter (LDF) system for measurement of blood perfusion. Fluorescence and blood flow were recorded millimeter-wise towards the pre-calculated target. In conclusion, the optical probe made real-time detection of tumor possible and has a potential for vessel detection during the biopsy procedures. Moreover, the PpIX fluorescence, autofluorescence and blood flow in the tumor could be studied at precise positions in the brain and the tumor. In the next step, further anal-ysis will be added.

Background

Using 5-aminolevulinic acid (ALA) as an intraoperative fluorescence contrast has been proven to improve the resection of glioblastoma and contribute to prolonged patient survival. ALA accumulates as protoporphyrin IX (PpIX) in the tumor cells and is administered in an advised dose of 20 mg/kg body weight (b.w.) for brain tumor resection using fluorescence surgical microscopes. PpIX fluorescence availability and intensities of a four folds lower ALA dose (5 mg/kg b.w.) has been investigated in glioblastomas and skin using a spectroscopy system adapted for surgical guidance.

Methods

A total of 30 adult patients diagnosed with high grade gliomas were included in the analysis. ALA was orally administered in doses of 5 mg/kg b.w. (n = 15) dissolved in orange juice or 20 mg/kg b.w. (n = 15) dissolved in water. A fluorescence spectroscopy system with a handheld fiber-optical probe was used for performing the quantitative fluorescence measurements.

Results

The binominal comparison of the diagnostic performance parameters showed no significant statistical difference (p > 0.05). The median fluorescence values in tumor were 2-3 times higher for the high ALA dose group. No PpIX was detected in the skin of the patients in the low dose group (0/4) while PpIX was detected in the skin of the majority of the patients in the high ALA dose group (13/14).

Conclusions

Application of 5 mg/kg ALA was evaluated as equally reliable as the higher dose regarding the diagnostic performance when guidance was performed using a spectroscopic system. Moreover, no PpIX was detected in the skin of the patients.

During stereotactic biopsy on suspected tumors in the brain, tissue samples are harvested to determine the malignancy. To provide guidance for finding the diagnostic tumor sites and to avoid vessel rupture, an application specific probe was developed. The setup incorporated spectroscopy for detection of 5-aminolevulinic acid induced protoporphyrin (PpIX) fluorescence and blood flow using laser Doppler flowmetry. The PpIX fluorescence was significantly different in the tumor compared to the gliotic marginal zone (p < 0.05). In conclusion, the systems made real-time tumor detection and vessel tracking possible. Moreover, the autofluorescence and blood perfusion could be studied in the tumor.

Since getting approved for clinical application in neurosurgery 5-aminolevulinic acid (ALA), that is a fluorescence contrast agent, has attracted the interest of many neurosurgical clinics to implement it in their surgical routine. ALA naturally exists in the body and the external administration of the substance induces accumulation of a fluorophore known as protoporphyrin IX (PpIX) in the malignant cells due to a broken blood brain barrier and the altered enzyme levels in the brain tumor. The detection and visualization of PpIX in the clinical routine is conventionally performed using a modified neuro surgical microscope. As a complementary technique for detection of ALA-induced fluorescence and to perform objective and quantitative measurements, our group has developed a spectroscopy system adapted to the equipment in the operating room. The system includes a hand-held fiber optic probe which can be integrated in the neuronavigation and stereotactic systems. The main advantages of the system are the ease of use, high sensitivity, quantitative fluorescence detection and the possibility of applying a low dose of fluorescence contrast agent while obtaining equally reliable results as with the high dose. In this contribution we present our experience, gains and challenges from implementation of the system during brain tumor surgery in forty adult patients. The methods and systems are currently being adapted for implementation during operations of pediatric brain tumors.

The deployment of pervasive computing technology and services has enabled the creation of smart environments which assist people in their daily activities. However, the deployment of technology and services into these smart environments has been obstructed due to many factors, most notably from the lack of proper models, rules and services. This thesis presents novel solutions for context-sharing intended to make utilisation of smart environments less complex and more cost efficient. It also presents solutions for mediated communication services which uses the power of smart environments to improve quality, flexibility and usability. The proposed solutions have all been evaluated through implementation and testing of proof-of-concept prototypes. Smart environments can provide a range of different services, such as giving warnings or reminders. Nevertheless, creation and personalisation of services can be complex and time consuming tasks, which promotes the creation of a common approach for tackling the heterogeneous nature of services and data. This thesis proposes such a common approach in the form of the openHome Suite which handles data collection, data analysis, and decision support for smart environments using XML. HomeML and HomeRuleML, two core components of the openHome Suite, supports sharing of context and rules with other research organizations and developers. It simplifies deployment through the creation of models which can be reused between smart environments. Tools for mediated communication are common in many smart environments. This thesis proposes how to utilise the smart environment to improve multimedia communication. A smart environment enables a user to transfer media content between devices for better quality, cost, and privacy. This thesis proposes context-aware communication and demonstrates how this can be established automatically by using the developed HomeRuleML approach, an approach which enables the representation and exchange of decision support rules. The study of context-aware communication and automatic establishment of communication has resulted in a new concept for communication called "dynamic groups" which is a simple and powerful group communication service. The concept has been proven through the development and evaluation of a prototype for mobile devices using near field communication. The research solutions presented in this thesis have been evaluated in the area of remote healthcare, for which simpler deployment of services into smart environments and better communication possibilities for patients becomes possible. This has the potential knock-on effect of decreased healthcare costs and improved support for the daily activities to improve a patient's wellbeing. Overall the work is done with an overarching aim for smart environments to help people stay out of hospitals in favour of living a richer life in their own homes.

As more and more people choose to live at home as they grow older the need for supportive environments increases. One of the identified needs is social interaction which can keep elders from becoming lonely and isolated. This need can be addressed by technology, but it has to be simple and intuitive to use, as the users may lack computer experience. The dynamic groups model is an attempt to solve this problem and provide users with context-aware group communication tools. A dynamic group model defines "group communication where the participants can be invited based on context and social networks in both physical and virtual settings". This model has similarities to existing communication solutions but dynamic groups offer new functionality such as automatic group formation based on predefined rules. This means a user could automatically be connected to a video-conference meeting with family members while eating breakfast, or be connected to healthcare personnel in the event of an accident.Dynamic groups utilize open standards for both context storage and decision support rules. This means it integrates into smart-environments and work together with other activity support services to provide better functionality. Furthermore it means that decision support rules can be tested and then shared with others for simple deployment. Setting up dynamic groups is then a matter of choosing between available rules, or creating new rules, which suit the user's needs. A user could for instance select rules like "breakfast with the family" or "notify healthcare personnel upon accidents". Furthermore, dynamic groups can be formed between co-located people in a simple manner. Through the user of for example Near Field Communication a group can be formed by reading a small tag. This could be quite useful for nurses who come to visit and wish to follow up on the house-call, or for the patient to help remember visitors, or even to talk to the visitors after they left. Dynamic groups make virtual social interaction simple and users are assisted in maintaining their social network through context-awareness and decision support rules.

This licentiate thesis presents ubiquitous systems for human communication and awareness from the perspectives of improving our everyday life experiences and relieving our scarcest resource, ourselves. The thesis also presents different methods of designing such systems with the user needs in focus. The goal of this work is to construct systems which support the user with context-based information and functionality that simplifies the user's tasks. The applied nature of this thesis is indicated by the three prototypes, which has been developed and evaluated. The first prototype provided spectators of sport-events with added information about the contestants and hence improved the experience of the event. The second prototype supported nurses in elderly care with their tasks by making organization and information gathering less time consuming and thus leaving more time for talking to the patients. Finally, the third prototype realized a system for ubiquitous human communication. The third prototype utilizes an algorithm for selecting and using media resources in the environment. This algorithm decouples several difficult problems and can be used to combine leading research in different areas of awareness together to create accurate resource selection. The motivation for creating prototypes has been to get experience from using systems which empower users and to find methods for satisfying user needs. Involving users early in the design process can help satisfy user needs. Hence, it is important to find methods and strategies for involving users, especially as not everyone can see the opportunities a new technology has to offer. In this thesis four methods and strategies are described and tested. These are paper prototypes, wizard of oz studies, questionnaires and real prototypes which were developed and then evaluated. These methods are compared and some of the findings are being discussed in this thesis. The evaluation of the prototypes and the user-studies show that it is possible to improve everyday life experiences using a combination of ubiquitous, pervasive, wearable and context-aware computing. A majority of all the users who answered the questionnaire for the first prototype answered that the system improved their experience of the sport event. The nurses who used the second prototype were positively surprised over how the technology could save both time and create a better group awareness. Most of the users who participated in the user-study for the third prototype were positive to using a mix of media resources to get richer communication, they were also in favour of using resources in the environment to save money and improve quality. The main results in this thesis are valuable insights into user opinions of ubiquitous systems, methods for involving users in the design process, and several design rules which can serve as a guideline for designing future ubiquitous systems.

This article presents the conceptual communication model of dynamic groups, that dynamically utilizes three traditional communication metaphors through the use of context-based information. Dynamic groups makes creation, management and usage of groups easy. It enables social network structures to be maintained in both virtual and face-to-face settings as well as in the combination thereof. This article defines the dynamic management of advanced contact lists which can include presence and status information, a/synchronous multimedia communication tools, and methods for structuring social networks. It also contains an initial evaluation and a proposed architecture for technical realisation.

There is a growing need in supporting social networking for groups who often become isolated, such as elders living at home. In a social network people with similar diseases and ailments can find each other and share information to improve their understanding of their illness. Group communication tools can help maintain a virtual social network and provide a base for information retrieval. Nevertheless, they often lack the strengths of the social networking tools and vice versa. Within this work we have developed a new concept called dynamic groups. Dynamic groups make creation, management, and usage of groups for communication and social networking easy. Nevetheless, for this to work the profile management system is required to handle more than just user information, it is required to provide users with control over their data and offer privacy and customisation capabilities. This article presents HomeCom, a model for profile management in dynamic groups. It also presents the solutions for making queries, as well as the solutions for privacy and customisation using multiple profiles and an integrated rule engine.

In this paper we present the reminiscence process in a prototype memory support tool for persons with mild dementia. The purpose is to promote autonomy for persons with mild dementia by supporting actualization and maintenance of episodic memories, and real-time access to a context-annotated life log.  The main research challenges are defined with a user scenario, Suitable reminiscence methods and memory entitities to reperesent life logs are described, and a preliminary architecture is presented. Finally an early design of a concrete ReviewClient is shown, to solicit feedback on the reminiscence methods, entitites chosen, architecture and the usability of the proposed interface.

This paper presents an evaluation of Bluetooth positioning in a general positioning platform. Proceeding the evaluation a Bluetooth based positioning system was implemented in order to complement the theoretical evaluation with empirical tests. Three different ways of positioning with Bluetooth have been developed. With a registered positioning service a Bluetooth device has an active role in the positioning task as it sends a position on request. A Bluetooth device can also take a more passive role in a positioning task, where the unique address of the device is used by a connected device to look up respective position in a database. It is also possible to forward a position gained from the positioning platform using the peer to peer characteristics in Bluetooth. This paper does also contain a discussion on the theoretical time requirements for a positioning system based on Bluetooth. Empirical tests show that these requirements hold.

The demands for smart environments, which can help to facilitate as well as monitor independent living are increasing. With this comes a desire for decision support rules to process data recorded from such environments. However, testing and evaluating rules can be both time-consuming and indeed stressful for the inhabitants. Within this paper we propose a model, referred to as HomeRuleML, for representing decision support rules for smart environments. The motivating factor behind such a proposal is to provide a widely and freely accessible set of rules which can be openly used and exchanged within the research domain and beyond. This model has the potential to decrease the time required for deployment, and inevitability improve the inhabitants' quality of life. In the paper we explain in detail the structure of adopting this approach and also provide an indication of the typical types of software tools required for its use.

The frequency with which items are misplaced increases with age, leading to increased frustration and anxiety especially for those who develop cognitive impairments such as dementia. Providing ICT support to assist with relocating items can significantly contribute to sustain independent living. In this paper we present a method for locating RFID tagged items throughout a home environment. Specifically, items are located by comparing and analysing signal strength, received from tagged items, with that received from anumber of fixed location reference tags. This paper presents experiments which have been performed within a typical living environment using homogeneous and practical placement of reference tags. This is performed to consider the feasibility of RFID positioning in such environments. Results obtained indicate that the approach provides acceptable location estimation in pervasive environments with sparsely placed reference tags, however, further investigation is required to accurately quantify its value

This paper describes a system where Internet-enabled sensor technology was integrated into a context information platform to give viewers of sport events an enriched media experience. The system was developed as a proof of concept and was evaluated during real-life use at the Vasaloppet cross-country ski event. Using Bluetooth wireless ad-hoc networking and GPRS technology, sensor data was transmitted from contestants to a context information platform, which in turn presented the sport event viewer with a personalized, context-aware view.

This paper describes a system where Internet-enabled sensor technology was integrated into a context-aware platform to give viewers of sport events an enriched media experience. The system was developed as a proof of concept and was evaluated during real-life use at the Vasaloppet cross-country ski event. Using Bluetooth wireless ad-hoc networking and GPRS technology, sensor data was transmitted from contestants to the context-aware platform Alipes, which in turn presented the sport event viewer with a personalized, context-aware view. In this paper we discuss the system architecture and integration of components. The system was evaluated both from technical and user perspectives, where the evaluation results confirm our approach to be technically feasible and that the system provide an enriched media-experience for the majority of viewers.

Excimer laser surgery, to correct corneal refraction, induces changes in corneal thickness and curvature. Both factors can cause measurement errors when determining intraocular pressure (IOP). This study evaluates effects of photorefractive keratectomy (PRK) on IOP measurements, using Goldmann applanation tonometry (GAT) and Applanation resonance tonometry (ART), in an in vitro model. Six porcine eyes was enucleated and pressurised to a constant IOP=30 mmHg. After removal of the epithelium, the eyes were PRK-treated for a total of 25 dioptres. The measured IOP decreased 13.2 mmHg for GAT and 9.0 mmHg for ART. The total underestimation by GAT was larger than for ART, and a part of the ART underestimation (3.5 mmHg) was assigned to sensitivity to the change in corneal surface structure resulting from the removal of epithelium. The flat contact probe of GAT, as compared with the convex tip of ART, provided explanation for the difference in IOP measurement error after PRK.

Glaucoma is a group of diseases associated with optic nerve damage and loss of visual field. The aetiology is not completely understood, but one of the major risk factors is elevated intraocular pressure (IOP). Reliable methods for measuring the IOP are therefore important. The aim of the study was to investigate the ability of the applanation resonance tonometry (ART) system, based on continuous force and area recording, to measure IOP in humans. Both the phase of initial indentation (IOPIndentation) and the phase when the sensor was removed (IOPRemoval) from the cornea were analysed. The Goldmann applanation tonometry (GAT) was used as reference method. The study included 24 healthy volunteers with normal IOP and 24 patients with elevated IOP. The correlation and standard deviation (SD) between IOPIndentation and IOPGAT was R = 0.92 (p < 0.001), SD = 3.6 mmHg, n = 104, and between IOPRemoval and IOPGAT R = 0.94 (p < 0.001), SD = 3.1 mmHg, n = 104. In conclusion, resonance sensor technology has made it possible to introduce a new multi-point method for measuring IOP, and the method is relevant for measuring IOP in humans. The study indicates that with further development towards elimination of position dependence, the ART has the potential to become a useful clinical instrument for IOP measurement.

We have developed an in vitro porcine eye model based on a biomicroscope, to simulate a clinical situation for IOP measurement on enucleated eyes. The aims of this study were to evaluate the model and to apply and compare Goldmann applanation tonometry (GAT) and applanation resonance tonometry (ART) measurements in porcine eyes. The GAT measurement (IOPGAT) showed a lower pressure, mean - 14.0 mm Hg (SD = 1.7 mm Hg) as compared with the reference pressure. For in vitro measurement with GAT on porcine eyes the linear calibration was IOP = 1.14 IOPGAT + 12.5 mm Hg (R2 = 0.99, p < 0.001, n = 280, four eyes). ART measurements correlated significantly to reference IOP, R = 0.86 (p < 0.001, n = 252, six eyes), with a mean difference of 5.4 mm Hg (SD = 6.7 mm Hg). GAT could only be used on porcine eyes if the IOP exceeded 13 mm Hg. Evaluation of the ART in this in vitro model showed position dependence for the sensor. To facilitate centre positioning a guiding tool is suggested. Porcine eyes are a possible substitute for human eyes in in vitro models for pre-clinical evaluation of new tonometry methods.

Accidental impacts to the human head are often a combination of translational and rotational accelerations. The most frequent severe brain injuries from accidents are diffuse axonal injury (DAI) and subdural hematoma that both are reported to arise from rotational violence to the head. Most helmet standards used today do only take the translational accelerations into account. It is therefore suggested that an oblique impact test that measures both translational and rotational accelerations should be a complement to the helmet standards used today. This study investigates the potential to reduce the risk for DAI by improving the helmet design by use of an oblique helmet impact test rig. The method used is a detailed finite element (FE) model of the human head. The FE model is used to measure the maximum principal strain in the brain which is suggested as a measurement for the risk to get DAI. The results clearly show the importance of testing a helmet in oblique impacts. Comparing a pure vertical impact with a 45 degree oblique impact with the same initial impact energy shows that the strain in the central parts of the brain is increased with a factor of 6. It is therefore suggested that a future helmet impact standard should include a rotational component so that the helmet is designed for both radial and tangential forces. Such a test method, an oblique impact test, was used to compare two different helmet designs. One helmet was manufactured with the shell glued to the liner and one helmet was designed with a low friction layer between the shell and the liner (MIPS). It was shown that the strain in the FE model of the human head was reduced be 27% comparing the MIPS helmet to the glued helmet design.

Accidental impacts to the human head are often a combination of translational and rotational accelerations. The most frequent severe brain injuries from accidents are diffuse axonal injury (DAI) and subdural hematoma that both are reported to arise from rotational violence to the head. Most helmet standards used today do only take the translational accelerations into account. It is therefore suggested that an oblique impact test that measures both translational and rotational accelerations should be a complement to the helmet standards used today. This study investigates the potential to reduce the risk for DAI by improving the helmet design by use of an oblique helmet impact test rig. The method used is a detailed finite element (FE) model of the human head. The FE model is used to measure the maximum principal strain in the brain which is suggested as a measurement for the risk to get DAI. The results clearly show the importance of testing a helmet in oblique impacts. Comparing a pure vertical impact with a 45 degree oblique impact with the same initial impact energy shows that the strain in the central parts of the brain is increased with a factor of 6. It is therefore suggested that a future helmet impact standard should include a rotational component so that the helmet is designed for both radial and tangential forces. Such a test method, an oblique impact test, was used to compare two different helmet designs. One helmet was manufactured with the shell glued to the liner and one helmet was designed with a low friction layer between the shell and the liner (MIPS). It was shown that the strain in the FE model of the human head was reduced be 27% comparing the MIPS helmet to the glued helmet design.

The aim of this paper is to explore how a digital caregiver, developed within a Swedish interdisciplinary research project, is humanised through health-enhancing practices of personalisation and friendliness. The digital caregiver is developed for being used in older patients’ homes to enhance their health. The paper explores how the participants (researchers and user study participants) of the research project navigate through the humanisation of technology in relation to practices of personalisation and friendliness. The participants were involved in a balancing act between making the digital caregiver person-like and friend-like enough to ensure the health of the patient. Simultaneously, trying to make the patients feel like as if they were interacting with someone rather than something – while at the same time not making the digital caregiver seem like a real person or a real friend. This illustrates the participants’ discursive negotiations of the degree of humanisation the digital caregiver needs in order to promote the health of the patient. A discursive conflict was identified between a patient discourse of self-determination versus a healthcare professional discourse of authority and medical responsibility: whether the digital caregiver should follow the patient’s health-related preferences or follow the healthcare professionals’ health rules. Hence, a possible conflict between the patient and the digital caregiver might arise due to different understandings of friendliness and health; between friendliness (humanisation) as a health-enhancing practice governed by the patient or by the healthcare professionals (healthcare professionalism).

Motion capture for biomechanical applications involves in almost all cases sensors or markers that are applied to the skin of the body segments of interest. This paper deals with the problem of estimating the movement of connected skeletal segments from 3D position data of markers attached to the skin. The use of kinematic constraints has been shown previously to reduce the error in estimated segment movement that are due to skin and muscles moving with respect to the underlying segment. A kinematic constraint reduces the number of degrees of freedom between two articulating segments. Moreover kinematic constraints can help reveal the movement of some segments when the 3D marker data otherwise are insufficient. Important cases include the human ankle complex and the phalangeal segments of the horse, where the movement of small segments is almost completely hidden from external observation by joint capsules and ligaments. This paper discusses the use of an extended Kalman filter for tracking a system of connected segments. The system is modeled using rigid segments connected by simplified joint models. The position and orientation of the mechanism are specified by a set of generalized coordinates corresponding to the mechanism's degrees of motion. The generalized coordinates together with their first time derivatives can be used as the state vector of a state space model governing the kinematics of the mechanism. The data collected are marker trajectories from skin-mounted markers, and the state vector is related to the position of the markers through a nonlinear function. The Jacobian of this function is derived The practical use of the method is demonstrated on a model of the distal part of the limb of the horse. Monte Carlo simulations of marker data for a two-segment system connected by a joint with three degrees of freedom indicate that the proposed method gives significant improvement over a method, which does not make use of the joint constraint, but the method requires that the model is a good approximation of the true mechanism. Applying the method to data on the movement of the four distal-most segments of the horse's limb shows good between trial consistency and small differences between measured marker positions and marker positions predicted by the model.

Rigid body pose is commonly represented as;he rigid body transformation from one (often reference) pose to another. This is usually computed for each frame of data without any assumptions or restrictions on the temporal change of the pose. The most common algorithm was proposed by Soderkvist and Wedin (1993, "Determining the Movements Of the Skeleton Using Well-configured Markers," J. Biomech., 26, pp. 1473-1477), and implies the assumption that measurement errors are isotropic and homogenous. This paper describes an alternative method based on a state space formulation and the application of an extended Kalman filter (EKF). State space models are formulated, which describe the kinematics of the rigid body. The state vector consists of six generalized coordinates (corresponding to the 6 degrees of freedom), and their first time derivatives. The state space models have linear dynamics, while the measurement function is a nonlinear relation between the state vector and the observations (marker positions). An analytical expression for the linearized measurement function is derived Tracking the rigid body motion using an EKF enables the use of a priori information on the measurement noise and type of motion to tune the filter. The EKF is time variant, which allows for a natural way of handling temporarily missing marker data. State updates are based on all the information available at each time step, even when data from fewer than three markers are available. Comparison with the method of Soderkvist and Wedin on simulated data showed a considerable improvement in accuracy with the proposed EKF method when marker data was temporarily missing. The proposed method offers an improvement in accuracy of rigid body pose estimation by incorporating knowledge of the characteristics of the movement and the measurement errors. Analytical expressions for the linearized system equations are provided, which eliminate the need for approximate discrete differentiation and which facilitate a fast implementation.

Achilles Tendon Rupture (ATR) is one of the typical soft tissue injuries. Accurately predicting the rehabilitation outcome of ATR using noisy measurements with missing entries is crucial for treatment decision support. In this work, we design a probabilistic model that simultaneously predicts the missing measurements and the rehabilitation outcome in an end-to-end manner. We evaluate our model and compare it with multiple baselines including multi-stage methods using an ATR clinical cohort. Experimental results demonstrate the superiority of our model for ATR rehabilitation outcome prediction.

Point-of-need devices perform analytical tests that help inform decisions where they are needed, away from modern lab infrastructure, be it in-field or in resource-poor settings. They have many applications, including veterinary medicine, agriculture, food safety, environmental monitoring, and forensics. In medical diagnostics, such devices are called point-of-care tests, and they could help combat societal challenges such as the spread of epidemic diseases and providing adequate healthcare in developing countries. Point-of-care devices could also be wearable to non-invasively monitor body fluids such as sweat or urine from the patient. Ideal point-of-care devices conform with the REASSURED criteria, that they should be Real-time connected, Easy to collect samples, Affordable, Sensitive, Specific, User-friendly, Rapid, robust, Equipment-free, environmentally friendly, and Deliverable to the end user.

We have here developed Point-of-need devices based on textiles and Printed Circuit Boards (PCBs); both well-established technologies that could offer low-cost mass production using existing industrial resources. Specifically, we have made electrochemical biosensors based on gold-coated yarn in a rolling architecture, as well as combined with wicking Coolmax® yarn acting as microfluidic channels in wearable systems, enabling advanced textile-based diagnostic devices suitable for automation or machine-stitching into fabrics. We also showed biosensors based on gold-coated PCBs that can connect to portable potentiostats for electrochemical detection and have integrated heating for isothermal nucleic acid amplification.

- To be trapped in a roller-coaster That ́s how some of the patients are describing the situa- tion of living with heart failure. To be stuck in their home not knowing if they will have to seek care today and not knowing if they will have the energy to attend that birth- day party later this week.Each year 2-3% of the Swedish population are diagnosed with heart failure, which results in 30,000 new individu- als with the disorder. Cardiovascular disease is rapidly in- creasing in the world and before 2030, people with heart failure will increased by 100%. Our improved living condi- tions and better health have allowed us to grow older and made us more dependent on other types of care, care at home.

Today the patients are only looking for changes in weight and if they have excessive water in their body. What if we could see changes in values before they develop in to symptoms? We could then use a smaller dosage of medicine and minimize the risk of damaging other organs.During my work I have met with patients, husbands, wives and care givers to gain a better insight and understanding of the different stakeholders problems. The common factor is the insufficient methods for monitoring that are being used today, which aren’t optimal for patients, relatives or care givers.That led me to look at non-invasive testing methods (PPG), which would make it possible to see a trend of a patients health. Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the microvascular bed of tissue. PPG is most often employed non-invasively and operates at a red or a near infrared wavelength due to its properties to permeate tissue. By sending out different wavelengths and recorde how much is transmit- ted, scattered and absorb, the sensor can measure levels in the blood.

When the station is done with the test it will send the result automatically to “Mina vårdkontakter” which will be accessible for both care givers and the patient. The profile will provide the patients with test results and a first contact holding advice for immediate and awaiting care. This will educate the patients and lead to them gaining a better understanding of their current health situation.

The topic of this thesis is on how text mining could be used on patient-reported symptom descriptions, and how it could be used to aid doctors in their diagnostic process. Healthcare delivery today is struggling to provide care to remote settings, and costs are increasing together with the aging population. The aid provided to doctors from text mining on patient descriptions is unknown.Investigating if text mining can aid doctors by presenting additional information, based on what patients who write similar things to what their current patient is writing about, could be relevant to many settings in healthcare. It has the potential to improve the quality of care to remote settings and increase the number of patients treated on the limited resources available. In this work, patient texts were represented using the Bag-of-Words model and clustered using the k-means algorithm. The final clustering model used 41 clusters, and the ten most important words for the cluster centroids were used as representative words for the cluster. An experiment was then performed to gauge how the doctors were aided in their diagnostic process when patient texts were paired with these additional words. The results were that the words aided doctors in cases where the patient case was difficult and that the clustering algorithm can be used to provide the current patient with specific follow-up questions.

Health care costs have increased over the last decades due to an ageing population. Therefore, research in personal health monitoring (PHM) has increased in response to this. PHM has advantages such as mobility (monitoring of health at work or at home), early detection of health problems enabling preventive health measures and a reduction of health care cost. Human motion analysis, using for example inertial measurement units and pedobarography, is an important subcategory of PHM. Pedobarography (PBG) is the study of pressure fields acting between the plantar surface of the foot and a supporting surface. Gait and posture analysis, prosthetics evaluation and monitoring of recovery from injury or disease are examples of PBG applications. Portable PBG can be performed using force sensing resistors built into the insole inside the shoe.

In accordance with this, the research goal for this licentiate thesis is to design, build and evaluate a wireless wearable measurement system based on pedobarography for monitoring of health. In order to fulfil the objectives of the research, literature studies were done and problems with existing in-shoe system solutions were identified. Thus, it was found that further opportunities existed for new designs of PBG systems which take these problems into account. Cross-sectional test case studies were used for validation. The research area is multidisciplinary and encompasses biomedical measurements, electronics and computer science.

The main research contributions include design and implementation of a PBG measurement system consisting of commercial off the shelf components, a novel method for selecting measurement samples for weight estimation of carried load during walk, and a novel method for analysing walking intensity using force-time integrals at the toe-off phase of the step. The research results suggest that the new PBG system, in combination with the two novel analysing methods, are suitable for use in wearable systems for monitoring of health. Personal health measurements are done to help decision making related to health. Thus, the future work will strive towards designing different decision support systems.

Assistive technology (AT) can be used as early intervention in order to reduce activity limitations in play and communication. This longitudinal case study examines eye-gaze control technology as early intervention for a young child with high spinal cord injury without the ability to make sounds. The young child was followed by repeated measures concerning performance and communication from baseline at 9 months to 26 months, and finalized at 36 months by field observations in the home setting. The results showed eye-gaze performance and frequency of use of eye-gaze control technology increased over time. Goals set at 15 months concerning learning and using the AT; naming objects and interactions with family was successfully completed at 26 months. Communicative functions regarding obtaining objects and social interaction increased from unintentional actions to purposeful choices and interactions. At 36 months, the toddler was partly independent in eye gazing, used all activities provided, and made independent choices. In conclusion, the results show that a 9-month-old child with profound motor disabilities can benefit from eye-gaze control technology in order to gradually perform activities, socially interact with family members, and make choices.

Monitoring of respiration is a central task in clinical medicine, crucial to patient safety. Despite the uncontroversial role of altered respiratory frequency as an important sign of impending or manifest deterioration, reliable measurement methods are mostly lacking outside of intensive care units and operating theaters. Photoplethysmography targeting the central blood circulation in the sternum could offer accurate and inexpensive monitoring of respiration. Changes in blood flow related to the different parts of the respiratory cycle are used to identify the respiratory pattern. The aim of this observational study was to compare photoplethysmography at the sternum to standard capnography in healthy volunteers. Bland Altman analysis showed good agreement (bias -0.21, SD 1.6, 95% limits of agreement -3.4 to 2.9) in respiratory rate values. Photoplethysmography provided high-quality measurements of respiratory rate comparable to capnographic measurements. This suggests that photoplethysmography may become a precise, cost-effective alternative for respiratory monitoring.

Laser induced thermal therapy (LITT) emerged in recent years as a minimal invasive treatment method for otherwise oftentimes inoperable brain tumors, such as glioblastomas. During the thermal ablation process, the procedure carries the risk of destroying healthy brain tissue adjacent to the tumor. Limitations in the spatial distribution of the real-time monitoring MR thermography system currently allow only a rough representation of the damage zone during surgery. For this reason, improved pre-operative simulations of tissue heating and the resulting tissue damage could be valuable to optimize clinical treatment protocols while minimizing the risks of the procedure. In this study a method is presented, to simulate the ablation process of the LITT with the finite elements method (FEM) using the simulation software COMSOL MULTIPHYSICS. Thereby the temperature distribution is displayed and, based on this, the extent of the tissue damage during the process is simulated. Therefore, relevant parameters for the ablation process, such as optical and thermal properties, blood per-fusion, and the interface between healthy and tumor tissue were investigated and their influence on temperature distribution and extent of tissue damage was described.

As many different 3D volumes could produce the same 2D x‐ray image, inverting this process is challenging. We show that recent deep learning‐based convolutional neural networks can solve this task. As the main challenge in learning is the sheer amount of data created when extending the 2D image into a 3D volume, we suggest firstly to learn a coarse, fixed‐resolution volume which is then fused in a second step with the input x‐ray into a high‐resolution volume. To train and validate our approach we introduce a new dataset that comprises of close to half a million computer‐simulated 2D x‐ray images of 3D volumes scanned from 175 mammalian species. Future applications of our approach include stereoscopic rendering of legacy x‐ray images, re‐rendering of x‐rays including changes of illumination, view pose or geometry. Our evaluation includes comparison to previous tomography work, previous learning methods using our data, a user study and application to a set of real x‐rays.