The first Metatarsophalangeal (MTP) joint is essential for foot biomechanics and weight-bearing activities. Osteoarthritis in this joint can lead to pain, discomfort, and limited mobility. In order to treat this, Episurf Medical is working to produce individualized implants based on 3D segmentations of the joint. As manual segmentations are both time- and cost-consuming, and susceptible to human errors, automatic approaches are preferred. This thesis uses U-Net and DeepEdit as deep-learning based methods for segmentation of the MTP joint, with the latter being evaluated with and without user interactions. The dataset used in this study consisted of 38 CT images, where each model was trained on 30 images, and the remaining images were used as a test set. The final models were evaluated and compared with regards to the Dice Similarity Coefficient (DSC), precision, and recall. The U-Net model achieved DSC 0.944, precision 0.961, and recall 0.929. The automatic DeepEdit approach obtained DSC of 0.861, precision of 0.842, and recall of 0.891, while the interactive DeepEdit approach resulted in DSC of 0.918, precision of 0.912, and recall of 0.928. All pairwise comparisons in terms of precision and DSC showed significant differences (p<0.05), where U-Net had the highest performance, while the difference in recall was not found to be significant (p>0.05) for any comparison. The lower performances of DeepEdit compared to U-Net could be due to lower spatial resolution in the segmentations. Nevertheless, DeepEdit remains a promising method, and further investigations of unexplored areas could be addressed as future work. / Den första Metatarsalphalangeal(MTP) leden är viktig för fotens biomekanik och viktbärande aktiviteter. Artros i denna led kan leda till smärta, obehag och begränsad rörlighet. För att behandla detta arbetar Episurf Medical med att producera individanpassade implantat baserat på 3D segmenteringar av leden. Då manuella segmenteringar både är tids- och kostnadskrävande, samt känsliga för mänskliga fel, föredras automatiska metoder. Denna avhandling använder U-Net och DeepEdit som djupinlärningsbaserade metoder för segm- entering av MTP leden, varav det senare utvärderas med och utan användarint- eraktion. Datasetet som användes i denna studie bestod av 38 CT bilder, där varje modell tränades på 30 bilder och de återstående användes som testdata. De slutliga modellerna utvärderades och jämfördes med avseende på Dice Similarity Coefficient (DSC), precision och recall. U-Net modellen uppnådde DSC 0.944, precision 0.961 och recall 0.929. Den automatiska DeepEdit metoden erhöll DSC 0.861, precision 0.842 och recall 0.891, medan den interaktiva DeepEdit metoden resulterade i DSC 0.918, precision 0.912 och recall 0.928. Alla parvisa jämförelser avseende precision och DSC visade signifikanta skillnader (p<0.05), där U-Net hade den högsta prestandan, medan skillnaden i recall inte visade sig vara signifikant (p>0.05) för någon jämförelse. Den lägre prestandan för DeepEdit jämfört med U-Net kan bero på lägre spatiell upplösning i segmenteringarna. Dock är DeepEdit fortfarande en lovande metod, och ytterligare undersökningar av outforskade områden kan tas upp som framtida arbete.

Diffusion-weighted magnetic resonance imaging (dMRI) is a powerful tool for thecharacterisation of neural tissue microstructural features. The role of neural projectioncurvature on the diffusion signal was recently studied for three temporal regimes of the diffusion pulse sequence in search for a description of the different decay trends in the orientationally-averaged diffusion signal reported in in vivo human studies.This work experimentally investigates the effects of neural projection curvedness in one of these regimes, namely the short diffusion time regime. Multi-shell diffusion MRI acquisitions on fixed rat spinal cord were performed using a custom number of diffusion gradient directions on a vertical bore pre-clinical MRI scanner capable of generating 3000 mT/m. Diffusion was probed in three different q-values ranges [450, 970], [600, 1400] and [1500, 1750] mm-1 using diffusion pulse durations of 1.4,2 and 2.5ms, respectively. Noise correction was performed on the diffusion data and the orientationally-averaged signal was computed for each shell using a weighted mean. The signal from selected regions in the sample was then fitted to a power law. Results show that gray matter areas exhibit a signal reduction with variable decay trends in the range of diffusion sensitivity values used here. This suggests that gray matter microstructure features are pictured by the orientationally-averaged signal in the high diffusion sensitivity regime and, as theoretically suggested, neurite curvature might play a role in characterizing the signal decay. These preliminary results may prove useful in the development of models for the interpretation of the diffusion signal and the design of acquisition strategies that aim to study the high diffusion sensitivity regime.

In conjunction with the always on-going technology development technical education have been created increasingly. Not least in the biomedical engineering area, which since 2008 has been established in Sweden. Between education and work, it can be assumed that there is a knowledge gap, which means that the workplace needs to supplement the previous studies with internal training. The following work analyses knowledge gaps in newly employed engineers in relation to what skills their working place requires. Furthermore, the study focuses on how the Akademiskas hospitals biomedical engineering department can work with internal training to introduce new employees. The result shows that the knowledge gaps differ greatly among individuals, but the common denominator is mainly applying the knowledge practically and electrical safety. Therefore, to create a flexible educational material to use in internal training of new employees, priority checklists are made which are divided into subject categories. The new employee thus gets the opportunity to practice his knowledge practically as well as theoretically. The theoretical material is created digitally and goes through the subject's underlying theory, demonstration of handling and training material, and the aim is that by letting the new employees go through this, the understanding and motivation of future tasks increases. Hopefully, by repeating the subject theoretical as well as practical the new employee will have a greater shot to process the task in his long-term memory and get a more covering and safer introduction of the workplace. / Universitet och högskolor har som skyldighet att skapa utbildningar baserade på konstnärliga eller vetenskapliga grunder som kan bidra till samhällsnytta. År 2008 skapades den första ingenjörsutbildningen i medicinsk teknik efter ett nära samarbete med industri och sjukhus. Syftet var att efter efterfrågan skapa en utbildning som gav studenterna specialkompetens inom medicin i samband med teknik för dagens alltmer avancerade sjukhusteknik.    Följande arbete utför en så kallad ”gapanalys” på kunskaperna hos en medicinteknisk ingenjörsstudent kontra en medicinteknisk ingenjör i arbetslivet på ett sjukhus. Vidare undersöker studien hur Akademiska sjukhuset kan arbeta med dessa kunskapsglipor vid anställning av exempelvis tidigare studenter för att få kompetenta ingenjörer som bidrar till arbete enligt den medicintekniska avdelningens uppdrag. Rapporten innefattar en förstudie och en studie där resultatet visar att det förekommer en stor variation på kunskapsbristerna mellan studenterna. Slutsatsen som däremot går att dra från studierna är att den stora kunskapsglipan ligger i att många ingenjörer aldrig har fått tillämpa den teoretiska kunskapen praktiskt. Många anser även att avsaknaden av ett elsäkerhetsmässigt tänk är ett stort och relativt utbrett problem. Särskilt med tanke på hur farligt ett sådant fel kan bli i sjukhusmiljö.    I förstudien svarar nio tidigare handledare på sjukhus runtom i landet på en enkät om vad de anser att studenterna som varit där på verksamhetsförlagd utbildning har haft svårt för. Många anser att kunskaperna kan variera mycket beroende på studentens intresse och bakgrund. Förstudien efterföljs av en intervjustudie på Akademiska sjukhuset som även den visar på en stor individuell kunskapsvariation hos studenter över olika ämnen. För att den medicintekniska avdelningen på Akademiska sjukhuset ska kunna skapa kompletterande utbildningar som täcker deras behov på kunskap skapas därför checklistor som även fungerar som en prioriteringsordning på ämnena som gås igenom i nyanställdas utbildning. På så sätt kan individens behov checkas av så väl som verksamhetens.    Prioriteringen görs på tre sätt; vilka kunskapsbrister som är mest framträdande, vad Akademiska sjukhuset anser riskfullt om personen inte har koll på samt vad som behövs för att den nyanställda ska känna sig bekväm på arbetsplatsen. Totalt skapas tre olika checklistor en som bör gås igenom omgående, en efter den nyanställda har fått landa i situationen och en där tillfälle ges för att fördjupa den nyanställdas förståelse och ansvarsområden.    Checklistorna innehåller teoretiska och praktiska moment där det praktiska sker ute på avdelning och det teoretiska materialet skapas i InfoCaption och publiceras i Akademiskas utbildningsportal. Upplägget på det teoretiska materialet som skapas är genomgång med stödjande bilder i PowerPoint för att lätt kunna gå tillbaka i materialet, demonstration av handhavande vilket sker med hjälp av filmer inspelade på avdelningen och slutligen en frågedel för att den nyanställda ska få reflektera över materialet. De olika teoridelarna delas in efter ämnen och efter genomgått ämne är tanken att den nyanställda ska få arbeta med detta praktiskt under övervakning av handledare för att få diskutera materialet och se hur det kan appliceras praktiskt.    Genom detta upplägg introduceras den nyanställda stegvis för framtida arbetsuppgifter, teorin repeteras innan den appliceras praktiskt vilket ökar sannolikheten för att processerna sätter sig i långtidsminnet. För att detta ska kunna implementeras på Akademiska sjukhuset anses däremot att fler studier behöver göras för att få en djupare helhetsbild över situationen. Den insamlade datan i studierna är begränsad och det är osäkerhet att den skulle täcka hela Akademiska sjukhusets medicintekniska avdelnings behov på efterutbildning av nyanställda.

Biodegradable implants continue to be of interest in orthopaedics for their many potential applications. The magnesium (Mg) alloy WE43 is a biodegradable material with the CE mark approval for clinical application and today mostly used as screws for dental prosthesis. Additional to magnesium, WE43 contains rare earth elements (REEs) of around 7 wt%. These REEs are needed to give the material its mechanical properties and corrosion resistance. Although WE43 is a promising material thought to be used in a diverse number of orthopaedical applications, questions have risen regarding the potential long-term effects of these REEs on the body after the implant degrades. Additionally, with the global demand of REEs rising and a decreasing supply of these elements, there may also be a potential future problem regarding the availability of materials based on REEs. Therefore, new materials containing only elements naturally found in the body are of interest. One such material is the novel Mg-Ca alloy, X0. In this study, a biological comparison was made to answer the question whether the biological performance of X0 is comparable to the already CE approved WE43. Viability, proliferation, and differentiation of MC3T3-E1 (preosteoblast) cells combined with extracts from X0 and WE43, respectively were used. An additional experiment was conducted were X0 was tested against three different versions of WE43 and titanium. In summary, the X0 alloy performed similarly to WE43 in all testing. Both WE43 and X0 showed indications of being bioactive. This led to the conclusion that the X0 alloy showed promise for future use and being a viable alternative to WE43.

In the current pursuit of sustainable energy, biofuel cells are attracting considerable attention. Within biomedical engineering, the concept of harnessing energy from biological fluids, such as blood, holds significant promise, enabling both full autonomy and miniaturization. In this context, this study aims to identify the most efficient biofuel cells for miniaturised implantable biosensors and design a prototype based on the obtained results. To achieve this goal, a systematic literature review was conducted, comparing biofuel cells based on relevant parameters for powering devices, including power density and operative voltages. This categorization guided material selection, considering a cost-performance trade-off. Carbon nanotubes and Laccase were chosen to facilitate oxygen reduction at the cathode, while carbon nanotubes with Glucose Oxidase (with and without ferrocenemethanol) played a similar role at the anode—where glucose proved to be the most advantageous fuel. Electrode functionalization and assessment involved electrochemical and morphological analyses, culminating in the recording of initial results for the biofuel cell prototype. The analysis of scientific literature revealed that under physiological conditions, including pH, glucose concentration, and single-chamber biofuel cells, the maximum power density obtained was 1 mW/cm$^2$ at 0.65 V. The use of nanomaterials, such as carbon nanotubes, and enzymes proved crucial for achieving this performance by enhancing electron transfer, increasing the effective area, and introducing specificity to each electrode, enabling the biofuel cell to operate without the need for a membrane. During the design phase, the functionalisation of the cathode highlighted the critical role of oxygen, which has a limited concentration in the solution. At the anode, the attempt to achieve mediated electron transfer proved successful, in contrast to the method of direct electron transfer. Finally, the characterisation of the biofuel cell demonstrated a preliminary power generation of 0.38 $\micro$W/cm$^2$ at 0.2 V in 500 mM glucose. The preliminary development of the prototype confirms the feasibility of generating energy with the selected materials and highlights its limitations, laying the foundation for its optimization—such as through a more robust stabilization method. Furthermore, the project proves valuable in the context of active medical device development, enabling a comparison between the requirements of a hypothetical implantable sensors and cutting-edge technology.

Ett foster har inte samma blodflöde och resistans mot förändringar i sin miljö som en vuxen människa har och kan vid små temperaturförändringar orsakas skada i till exempel den utvecklande hjärnan. Vid ultraljudsundersökning finns bevisat en viss värmeökning, men det råder ovisshet kring hur stor denna skulle kunna bli under en längre tids exponering av ultraljud. Syftet med detta arbete var att undersöka värmeutvecklingen vid obstetriskt ultraljud genom att utforma en 3D-modell i mjukvarumiljön COMSOL Multiphysics version 6.0. En modell kan bidra med kunskap för att besluta kring om riskerna med temperaturökning hos foster till följd av ultraljud behöver studeras vidare. Resultaten av framtagen modellering visade på en mycket liten uppvärmningseffekt. Slutsatsen drogs att om modellen i 3D ska kunna göra trovärdiga beräkningar i programmet krävs en mer avancerad dator än vanligt, med betydligt större minneskapacitet. Vidare utveckling av modell i COMSOL bör göras i 2D, alternativt med en mer avancerad dator, för att få tillförlitliga resultat. / A fetus does not have the same blood perfusion and resistance to changes in its environment as an adult and small changes in temperature can cause irreversible damage for example to the fetal brain. Ultrasound examinations are proven to cause some heat gain but there are uncertainties regarding the amount of heat gain during a longer time of ultrasound exposure. The purpose of this study was to analyse the heat development during obstetric ultrasound by designing a 3D-model in the software environment COMSOL Multiphysics version 6.0. A model could contribute to knowledge in making an informed decision whether the risks of heating in a fetus because of ultrasound are necessary to study further. The results of the developed model showed a very small heating effect. The conclusion was made that if the model in 3D is to be able to make correct calculations in the programme it is required to use a more advanced computer than usual, with significantly greater memory capacity. Further development of a model in COMSOL should be made in 2D, or with a more advanced computer, to get reliable results.

Currently available VR-diversion solutions for vaccination lack key features for delivering an immersive and pleasurable experience. A tailor-made diversionary semi-interactive VR-experience software for vaccination procedures has been developed using mainly the game engine Unity and programmed in C#. The software aims to reduce or prevent anxiety, fear, and pain during these procedures. It is predominantly intended to be used by children as a tool for prevention. The narrative of the experience runs in parallel with the different steps and events of a vaccination procedure on the left arm. The interactions from the patient are only made using head gestures and no other controllers or movements of the body are used. The sequence can be initiated, restarted, and followed by a healthcare professional using a controller. The software is in a testable and applicable state but can be improved upon and polished in various areas. / Nuvarande VR-avledningslösningar för vaccination saknar viktiga funktioner för att leverera en immersiv och trevlig upplevelse. En skräddarsydd avledande semi-interaktiv VR-upplevelseprogramvara för vaccinationsprocedurer har utvecklats med huvudsakligen spelmotorn Unity och programmerats i C#. Programvaran syftar till att minska eller förebygga ångest, rädsla och smärta under dessa procedurer. Den är främst avsedd att användas av barn som ett förebyggande verktyg. Berättelsen i upplevelsen löper parallellt med de olika stegen och händelserna i en vaccinationsprocedur på vänster arm. Interaktionerna från patienten görs endast med hjälp av huvudgester och inga andra kontroller eller rörelser av kroppen används. Sekvensen kan initieras, startas om och följas av sjukvårdspersonal som använder en handkontroll. Programvaran är i ett testbart och tillämpligt tillstånd men kan förbättras och poleras inom olika områden.

A digital twin project is launched by the Integrative Systems Biology (ISB) research team and led by Gunnar Cedersund. The digital twin project is based on biological models of physiological processes, that can interact and be tailored for a specific person. However, the digital twin can currently not analyse movements of a human body. In this master thesis, the aim was to create a useful pipeline that expands the digital twin project with biomechanical modelling of movements, and also visualises the twins by letting the concept take human form. The biomechanical analysis was done in the software OpenSim, where the movements of a motion captured dance were analysed. To generate a simulation of the motion with an acceptable error in a reasonable computation time, a musculoskeletal model was created in OpenSim and scaled to best fit the anthropometry of the dancer. Then, the motion was estimated with an optimised procedure by using the scaled model and the motion capture data. The Root-Mean Squared (RMS) error of the estimated dance with accuracy 10-6 was 2.39 cm. In this thesis, the torque in each joint for the dance motion was estimated. The loads and muscle forces can also be estimated in OpenSim. One useful application is for calculating energy consumption. In order to calculate muscle forces, external forces needs to be measured while recording motion capture. This is something that will be focused on in the future, when continuing with this project. The visualisation of the digital twins were made in Unreal Engine with MetaHuman avatars. The dance recorded in motion capture, were applied to the avatars in order to make them dance. The recorded dance was the same for both OpenSim and Unreal Engine, so the dance could both be viewed and analysed. In conclusion, we have added a new feature to the existing digital twin technology: movements and simulation of the musculoskeletal system. This new feature can in the future be used for both medical purposes such as movement-based rehabilitation as well as for integration into dance performances.

Parkinson’s Disease (PD) is a neurodegenerative disorder, within this categoryof diseases it is among the most prevalent worldwide. The etiology of PD isbased in progressive deterioration of neural tissue in the basal ganglia (neuronalnuclei located at the base of the cerebrum) and their related structures. Current research is focusing on treatment approaches to either enhance or replaceexisting pharmaceutical treatment approaches, such as dopamine replacementtherapy. In this project, the focus was on finding correlates between movementdata and neurological signals to provide insight into potential biomarkers forcomplex motor symptoms of PD. This will in turn provide a starting point forspecifically targeted closed-loop neural stimulation that alleviates these symptoms. Although the data available at the time of this thesis did not providesufficient insight to derive a conclusion on the neural correlates, a pipeline wasdeveloped, which analyzes and synchronizes kinematic and neural data and willenable further exploration as additional data is obtained.

Frequency domain functional near infrared spectroscopy (FD-fNIRS) is a tissue optical measurement technique used to measure absolute haemoglobin concentrations in brain tissue. This work is intended to be the first step in the development of a wearable, low-cost FD-fNIRS device for neurofeedback applications. The system requirements were generated from a review of relevant literature. A simplified system architecturewas developed based on the various instrumentation methodologies proposed by various authors. The functional blocks of this system were prototyped and their performance was evaluated. The developed vertical-cavity surface-emitting laser (VCSEL) current source was found to have a span of 10uA which meets the design specifications. Challenges exist in optimally biasing silicon photomultiplier (SiPM), which is susceptible to optical and electronic noise sources.