PET imaging is a key tool in the fight against cancer. One of the main issues of PET imaging is the high level of noise that characterizes the reconstructed image, during this project we implemented several algorithms with the aim of improving the reconstruction of PET images exploiting the power of Neural Networks. First, we developed a simple denoiser that improves the quality of an image that has already been reconstructed with a reconstruction algorithm like the Maximum Likelihood Expectation Maximization. Then we implemented two Neural Network based iterative reconstruction algorithms that reconstruct directly an image starting from the measured data rearranged into sinograms, thus removing the dependence of the reconstruction result from the initial reconstruction needed by the denoiser. Finally, we used the most promising approach, among the developed ones, to reconstruct images from data acquired with the KTH MTH microCT - miniPET.

Motor vehicles collisions and falls have gradually increase the risk for spinal cord injuries. An increased knowledge of the spinal behavior and its injury mechanisms can be used as preventive strategies. Total Human Model for Safety (THUMS) SAFER is used as a tool for injury prevention, however, there is a lack of studies that evaluate the spinal cord injuries. The aim of this thesis is to implement a cervical spinal cord into the THUMS model. The mesh element quality was modified and the spinal cord was further adjusted for a correct insertion into the THUMS. The strain of the posterior and anterior surface of the cervical spinal cord during a head flexion were analyzed against experiments. Subsequently, a comparison of the head kinematics in frontal collision of the THUMS with and without the cervical spinal cord was performed. A refinement of the mesh element quality for a suitable computational time was achieved. The strain evaluation of the the spinal cord showed the same behavior as in the experiment for the posterior surface but the results were contradictory for the anterior surface. The results of the head kinematics with and without spinal cord showed no good correlation with the experimental data. Moreover, the models exhibited a bigger difference between them during the extension of the head than flexion. A further improvement of the mesh element quality required smaller element size. Nonetheless, it is important to consider that computational time increases with a decrease of element size. Several factors were critical for the strain comparison, such as the lack of information for the calculation of the strain. The difference in head kinematics from the experiment may be due to the material properties of the neck skin and the lack of the active muscles. Moreover, the contact constraints in the model may result in the differences between the THUMS models. In general, the spinal cord has been refined to obtain a favorable computational time. The evaluations have indicated that further modifications in the neck skin and contact constraints are needed for a better resemblance with the human body. Likewise, further validations against experimental studies are suggested.

Den ökade belastningen på akutmottagningar i Sverige bidrar till ett kraftigare flöde till röntgenavdelningar. Detta leder till en ökad arbetsbelastning för personalen på avdelningen och skulle med hjälp utav en skärm kunna underlättas. Syftet med studien var att se på möjligheter att implementera en sådan lösning på Södersjukhusets röntgenavdelning. Metoden innefattade en arbetsplatsstudie av röntgenavdelningen såväl som en analys av manualer samt intervjuer med personal associerade med sjukhusets olika databassystem, bland annat TakeCare, RIS och PACS. Resultaten visade att en sådan lösning går att finna i TakeCare, dock så skulle framtagningen av denna lösning vara en långdragen och avancerad process. Detta beror främst på de olika krav som ställs på medicintekniska produkter, bland annat på grund av patientdatasäkerhet. / The increasing encumbrance on Emergency Rooms in Sweden contributes to a vigorous flow to theX-ray Clinics. This leads to an increasing work load for the personnel on the X-ray Clinic, and theywould benefit from having a screen that shows the flow of patients from the Emergency Room tothe X-ray Clinic. The purpose of this study was to investigate possibilities to implement such an aidon the X-ray Clinic at Södersjukhuset. The method consisted of an observation of the X-ray Clinicand analyses of manuals and interviews with personnel associated to different database systems,such as TakeCare, RIS and PACS. The results showed that a solution exists in TakeCare. However,the production of this solution would result in a long and advanced process. This is due to the different requirements on medical products, partially because of the law regarding patient data security.

Introduction: Concussions in American Football are of a major concern due to highly reported injury rates. The importance of properly designed helmets have shown effect in reducing the risk of injuries, such as skull fractures. However, they are not as effective in reducing the risk of concussion. Helmets designed are required to pass standards and regulations for them to be allowed within the football leagues. The current test methods evaluate linear impacts, but lack evaluations of oblique impacts which are believed to cause concussions. Several test methods have been suggested, but little is known regarding how they compare. Objective: The purpose of this study was to compare three different test methods for evaluating helmet performance, utilizing finite element simulation. Three different helmet models were used for comparison, evaluating head kinematics. The helmet models were additionally ranked from best to worst based on their performances. Method: Three test methods, linear impactor, 45° angled linear impactor, and a drop test onto a 45° angled plate were simulated with three different open source helmet models. Simulations were conducted with one impact velocity at three impact locations. The influence of the interaction between helmet and head was also evaluated by altering the friction coefficient. Results: The test methods showed different results depending on helmet models, impact locations, and kinematics evaluated. Similarly, rankings of the helmets were varied based on methods and impact location. Little difference was observed after lowering the friction coefficient in majority of cases. The linear and angular acceleration for the drop side impact were mostly affected. Conclusion: Further evaluations of the test methods and comparison to real impacts is required to evaluate what method resembles head impacts best. Lowered friction coefficient had an effect for the drop impacts, but minor effect for other test methods

Exoskeletons can be helpful to patients who suffer from muscular dysfunctions. Recent studies focus on exoskeletons which can perform complex human movements. Further analysis is needed in the area of unusual movements like obstacle clearance to design an assistive device which can deliver effective aid to the intended patients in need. It is necessary to understand the behavior of lower limb muscles when they are subjected to complex physical activity. This study is aimed to analyze the activity of muscles in the lower body during obstacle clearance. Two different levels of obstacle have been maintained, analyzed and compared with a normal gait. The muscle groups taken for the study are quadriceps, hamstrings and plantar flexors. The primary hypothesis is that the quadriceps, Hamstrings, and dorsi flexors tend to have higher muscle activation while performing a complex physical task like stepping over an obstacle with the heights of 20 cms and 36 cms than a normal walking gait. The muscles from those three mentioned groups contribute more to the obstacle clearance compare to that of normal gait. Further research is recommended to expand knowledge about muscle activation.

Sweden's aging population makes the need for a viable health care urgent and telemedicine can be a solution to enable older people to receive or give themselves care in their homes. Furthermore, implementation of telemedicine has the potential to realise profits in society by increasing the accessibility of health care and minimizing travel costs. Sweden’s low population density and geographical configuration makes the advantages of telemedicine even more appealing.   To illustrate the differences between the county councils’ use of telemedicine and thus increasing the possibility for coordinated care between them, the authors have on behalf of the Innovation Centre at the Karolinska University hospital mapped the amount of telemedicine technologies that are available in the Swedish county councils’ today. To collect information an electronic survey and video or telephone interviews were used. This report answers the question of how the use of telemedicine differ between Sweden's county councils in terms of techniques used, how well implemented the technologies are and to what extent the guidelines for development, implementation and use of telemedicine is available. The report also investigated whether the county councils geographic characteristics, in terms of population density and the number of hospitals and health centers, influenced the development of telemedicine.   Of the 21 regional councils information has been collected from 10 counties in seven weeks and the results that were collocated indicated that there are major differences between the county councils' use of telemedicine. It is clear that the northern region and especially Västerbotten and Norrbotten County Council have come a long way in implementing telemedicine technology.   When the results of the electronic survey and interviews were compared with the county councils’ geographical features no correlation could be detected between population density and the use of telemedicine. This can be a result of the low number of participating counties and that we have not examined all departments in health care. The county councils which have university hospitals use multidisciplinary rounds more so than others. In summary, the Swedish county councils are at different stages in the implementation of telemedicine due to several external and internal factors that makes it possible for counties to benefit a lot from collaboration and sharing each other's knowledge. / Sveriges åldrande befolkning gör behovet av en fungerande vård stor och telemedicin kan vara en lösning för att ge äldre möjlighet att få eller ge sig själva vård i hemmet. Genom implementering av telemedicin har Sverige på grund av sin låga befolkningstäthet och geografisk utformning potential att öka tillgängligheten av vård och minska resekostnader.   För att belysa skillnader mellan landstingens användning av telemedicin och på så sätt öka möjligheten för samordnad vård mellan landstingen har författarna på uppdrag av Innovationsplatsen på Karolinska Universitetssjukhuset med hjälp av elektronisk enkät och video- eller telefonintervjuer kartlagt hur mycket telemedicinsk teknik som finns tillgänglig på Sveriges landsting idag. I rapporten besvaras frågeställningen hur användningen av telemedicin skiljer sig mellan Sveriges landsting i avseende på vilka tekniker som används, hur väl implementerade i verksamheten teknikerna är samt i vilken omfattning riktlinjer för utveckling, implementering och användning av telemedicin är tillgängliga. Rapporten har även undersökt om landstingens geografiska egenskaper i form av befolkningstäthet samt antal sjukhus och vårdcentraler påverkat utvecklingen av telemedicin inom landstingen.   Av Sveriges 21 landsting har information samlats in från 10 landsting under sju veckor och resultatet som sammanställdes tydde på att det finns stora skillnader mellan landstingens användning av telemedicin. Det är tydligt att norra regionen och speciellt Västerbottens- och Norrbottens läns landsting har kommit långt i implementering av telemedicinsk teknik.   Då resultaten från den elektroniska enkäten och intervjuerna jämfördes med landstingens geografiska egenskaper drogs slutsatsen att inget tydligt samband kunde upptäckas mellan befolkningstäthet och användandet av telemedicin. Slutsatsen kan bero på för få deltagande landsting och att undersökningen inte utfördes på varje avdelning. En annan slutsats som var tydlig var att landsting som har universitetssjukhus i större utsträckning använder multidisciplinära ronder via videokonferensteknik. Sammanfattningsvis har Sveriges landsting kommit olika långt i utvecklingen av telemedicin på grund av flera yttre och inre faktorer vilket gör det möjligt för landstingen att dra stor nytta av varandras kunskap vid samarbete.

Medicinteknik är ett fält med en hög grad av digitalisering som erbjuder många viktiga tjänster inom sjukvården. Sjukvården har på senare år visat sig sårbar för intrång och cyberattacker med goda incitament för fientliga aktörer. Mer uppkopplade system förenklar användningen och integreringen av olika medicinska apparater och system men medför även risker som en följd av att mer av systemet blir tillgängligt för externa aktörer. Nya innovationer och en mer digitaliserad bransch kan alltså medföra problem om nödvändiga säkerhetsåtgärder inte vidtas. Branschen undersöks utifrån följande frågeställning: Hur arbetar medicintekniska företag för att motverka risker och hot inom cybersäkerhet? För att belysa nutidsläget inom branschen gjordes med en kvalitativ utgångspunkt en kartläggning av de risker och hot som branschen upplever med avgränsning på små och medelstora företag inom Sverige. Data samlades in genom ett antal semistrukturerade intervjuer med viss anpassning utifrån organisationens verksamhetsbeskrivning.Totalt utfördes 15 intervjuer, 13 med företag verksamma inom medicinteknik eller medicinframställning. En intervju utfördes med en kontakt på Läkemedelsverket och en intervju utfördes med två kontakter som arbetar med informationssäkerhetsfrågor inom en svensk region. Intervjuerna analyserades sedan med hjälp av tematisk analys. Den tematiska analysen resulterade i sju teman. Bland de intervjuade verksamheterna bedömdes generellt risken för intrång i verksamheten som låg, tjänster eller anslutna produkter som brukas av slutanvändare uppfattades dock som mer utsatta. Intervjuerna utfördes under en övergångsperiod till nya förordningar som ställer strängare krav på patientsäkerhet samt cybersäkerhet för medicintekniska produkter. Kraven som dessa förordningar ställer samt eventuella krav från vården identifierades som den primära motivationen att investera i informationssäkerhet bland de intervjuade företagen. Ett flertal respondenter framförde kritik mot de nya regelverken och hävdade att arbetet som krävs för att uppnå kraven är alltför omfattande för mindre verksamheter och risken att företag eller produkter skulle lämna marknaden som en följd framhävs. Synpunkten från Läkemedelsverket och regionen skiljde sig och de betraktade kraven som ställdes som rimliga samt nödvändiga.Resultaten från intervjuerna visar ett behov av ökat stöd för små och medelstora verksamheter för att kunna uppnå de krav som ställs samt vägleda mindre verksamheter. / MedTech is a sector with a high degree of digitization and responsible for providing many of the innovations and services the health care sector makes use of. In recent years the healthcare sector has shown itself to be vulnerable to intrusions and cyberattacks. Increasingly connected devices confer benefits through increased interoperability of devices and systems, easier access and handling of medical records along with general ease of use. Connecting these devices also puts them at risk of being remotely accessed however, meaning many recent innovations may be problematic if these risks are not properly mitigated. Given how interwoven the sectors mentioned above are there is a high likelihood that insufficient security measures in Medtech will impact healthcare adversely. In hopes of illuminating some of the threats and risks the MedTech sector is currently facing, the following question is asked: How do companies within MedTech work to mitigate cybersecurity risks and threats? To answer these questions a survey was done with focus on small and medium sized entities within MedTech based in Sweden. Data was collected through interviews. A total of 15 interviews were conducted, 13 of which were interviews with companies active within the field of MedTech or medicine.One interview was performed with Läkemedelsverket, a supervisory authority within MedTech and one interview was performed with two contacts within a Swedish county council who hold advisory roles regarding information security. The transcribed interviews were analysed thematically to discern common patterns and findings throughout the interviews. The thematic analysis resulted in 7 themes. Among the interviewed companies the majority perceived the likelihood of an intrusion within their company as low and security efforts were primarily directed towards the service or product on offer where the risk and eventual consequences of an intrusion was deemed to be higher. The interviews took place during a transitional period between old directives and new regulations with more stringent requirements regarding security and cybersecurity for medical devices. Complying with the new regulations and eventual requirements from caregivers were the primary motivators behind investment in cybersecurity among the interviewed companies. A number of respondents critiqued the new regulations on the grounds that the workload complying with the regulation brings is excessive for small enterprises and might cause an exodus of products and companies from the sector. This view was not shared by the respondent from Läkemedelsverket nor the respondents from the Swedish county council who considered the new requirements reasonable and necessary. The results show a need for further support among small and medium sized enterprises in order to handle regulatory demands.

Critical care patients are often connected to ventilators, to support or replace their breathing. The ventilators deliver a mixture of gas to the patient by applying a specific volume or pressure, and then the patient exhales passively. This thesis is based of the hypothesis that a slower reduction of the expiration pressure could benefit intensive care patients connected to a ventilator. To enable research within the area, a device which can control the expiration is needed. In this thesis project, an expiration valve was controlled to create different pressure patterns during expiration. To facilitate the research and the usage of the expiration control, an application software was created with the purpose to simulate relevant pressure, flow and volume curves. The prototype is an expiration cassette created for the ventilator Servo-i by Maquet Getinge Group. To enable flexibility, the prototype is external and no information is transmitted from or to the ventilator. The prototype has its own flow and pressure sensors. The different pressure patterns which the prototype uses are designed as a linear decrease and as if a constant resistance was added to the system. The user can also create their own pressure pattern, by deciding 20 pressure points in the duration of two seconds. The simulation application was designed with the ability to simulate the same pressure patterns available with the prototype. By using a lung model, it is possible to simulate the ideal pressure, flow and volume in the lungs which can be expected from the chosen expiration control. During the implementation, two different types of lung models were evaluated in order to determine the specificity required. The prototype was tested with settings which were chosen to challenge the performance of the control. Some problematic areas were detected, such as high pressures or large volumes. However, the prototype was judged to perform well enough to be used in animal trials. The lung model used for the simulation application was a simple model of the lung, consisting of a resistor and a capacitor in series. The simulations were compared with the real system with the purpose to get an indication on the difference between theory and reality. The application presents the expected behavior when using the expiration control. However, it should be kept in mind by the user that the application represents a theoretical model.

Tractography is widely used in the brain connectivity study from diffusion magnetic resonance imaging data. However, lack of ground truth and plenty of anatomically implausible streamlines in the tractograms have caused challenges and concerns in the use of tractograms such as brain connectivity study. Tractogram filtering methods have been developed to remove the faulty connections. In this study, we focus on one of these filtering methods, Convex Optimization Modeling for Microstructure Informed Tractography (COMMIT), which tries to find a set of streamlines that best reconstruct the diffusion magnetic resonance imaging data with global optimization approach. There are biases with this method when assessing individual streamlines. So a method named randomized COMMIT(rCOMMIT) is proposed to obtain multiple assessments for each streamline. The acceptance rate from this method is introduced to the streamlines and divides them into three groups, which are regarded as pseudo ground truth from rCOMMIT. Therefore, the neural networks are able to train on the pseudo ground truth on classification tasks. The trained classifiers distinguish the obtained groups of plausible and implausible streamlines with accuracy around 77%. Following the same methodology, the results from rCOMMIT and randomized SIFT are compared. The intersections between two methods are analyzed with neural networks as well, which achieve accuracy around 87% in binary task between plausible and implausible streamlines.

One of the main characteristics of Parkinson's disease (PD) is an exaggerated oscillatory activity in the beta band (12-30 Hz). This activity has been linked to the rise of symptoms such as bradykinesia and akinesia. Even if dopamine replacement therapy (oral intake of dopamine pro-drug levodopa) reverses these symptoms, the effect of the treatment on the beta band activity has still not been completely understood. Therefore, here the temporal dynamics of beta band activity in human patients affected by PD were characterized with and without levodopa treatment. Local-field-potential (LFP) recordings from five patients undergoing dopamine replacement therapy were used. From the LFPs, the extracted beta epochs with significantly higher power than expected from a comparable noisy signal were analyzed. This analysis showed that beta band activity occurred in bursts meaning that high amplitude oscillation alternated with silenced periods. The pathological state also distinguished itself for longer epochs and with power that increased with the length of the epoch. The administration of levodopa reduced the duration of bursts and decreased the overall mean power of the beta band activity. Finally, epochs with the same number of cycles were compared. The Coefficient of Variation prior such epochs suggested that the ongoing activity might lock into a synchronization process prior the burst. These results provide important information to better understand how levodopa alleviates some of the symptoms of PD and pave the way to develop better computational models for the emergence of beta oscillations.