The main objective of this project was to develop a method for soft neural probe insertion into a nerve. These soft probes are made of a silicon elastomer that is a few orders of magnitude less stiff than the nerve, which makes the insertion process particularly challenging. To overcome this challenge a tungsten microwire was used as an insertion shuttle to help penetrate the nerve by increasing the overall stiffness of the probe. At a first stage, the insertion process was tested on a nerve phantom (e.g. agarose gel with PDMS membrane) to control the insertion parameters and validate the insertion platform. Once the envisioned insertion method was established, the probe was implanted in a real rodent nerve. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

In cancer research, studies on cells are often done in 2D, grown on plates which are not realistic. Therefore, a specialized system is being designed to build 3D cell structures. This system requires a fitting amplifier that is of low cost and changeable gain. The aim of this project was to design, simulate and build a custom amplifier circuit card, PCB, to be used in creating such an amplifier. At the end of the project the custom amplifier PCB should be connected with components such as power supply and should be able to take the place of the current one. The amplifier circuit was designed, and the simulations were tested, a finished design was created. Due to shortage of electronic components, the main IC component could not be acquired and hence a finished circuit could not be built. / Inom cancerforskning görs studier ofta på celler i 2D strukturer, plattor och detta är inte realistiskt. Därför utvecklas det ett nytt sätt att bygga cellstrukturer i 3D. Detta system kräver en anpassad förstärkare av låg kostnad och anpassningsbar förstärkning. Syftet med detta projekt var att bygga ett förstärkarkretskort. Inom metoden gjordes simulering, tester och utveckling av en krets samt bygge av ett förstärkarkretskort. Detta kort skulle kopplas till andra komponenter som nätaggregat och moderkort för att ersätta den nuvarande förstärkare. Simulering och design av krets gjordes men ett färdigt kort kunde inte testas på grund av leveransproblem av elektriska komponenter.

På grund av det höga trycket på akutmottagningar räcker inte resurserna till och patienter får vänta länge på att få vård. Situationen är ännu värre i utvecklingsländer där det redan finns brist på resurser. För att handskas med detta problem behöver dagens akutmottagningar utvecklas och innovationer göras för att effektivisera användandet av resurser. Målet med detta arbete blev därför att utveckla en multifunktionell diagnostisk enhet som skulle kunna mäta flera vitalparametrar och som samtidigt var billig, kompakt, tidseffektiv och användarvänlig. För att uppnå målet analyserades vitalparametrarna kroppstemperatur, pulsfrekvens, andningsfrekvens, blodtryck och syremättnad samt deras mätmetoder. På grund av projektets begränsade resurser gjordes bedömningen att endast ett teoretiskt förslag på ett instrument som uppfyllde ovanstående krav skulle framställas. Analysen visade att endast pulsfrekvens, blodtryck och syremättnad kan mätas med samma instrument som fortfarande var billigt, kompakt, tidseffektivt och användarvänligt. Instrumentet som mäter dessa tre parametrar är en modifierad variant av en multivåglängds fotopletysmograf. För kroppstemperatur och andningsfrekvens föreslogs det att redan existerade billiga och användarvänliga metoder skulle användas, nämligen digital termometer respektive att observera patientens andning under en minut. Arbetet resulterade i att det togs fram figurer, flödesscheman och ett kretsschema för den multifunktionella diagnostiska enheten som skulle kunna användas för att bygga en prototyp. Därutöver evaluerades pulsoximeterns användarvänlighet då det föreslagna idén skulle vara av samma utseende som pulsoximeter. Det resulterande förslaget på diagnostisk enhet bedömdes vara till viss del anpassad för att kunna användas på akutmottagningar i Bangladesh och är anpassad för hur vården är uppbyggd där idag och dess rutiner.

<p>Car exhaust catalysts were introduced in the early 1980’s, to limit the release of pollutants such as hydrocarbons, carbon monoxides and nitrogen oxides. These catalysts contain noble metals such as palladium (Pd), platinum (Pt) and rhodium (Rh) and are able to simultaneously abate all three of the above-mentioned pollutants, hence the name three-way catalyst (TWC). The exposure to high temperatures (800-1000 °C) during operation and the presence of additives in petrol such as lead, calcium, silicon, magnesium, manganese, chromium, sulphur and phosphorus will after a certain time start to lower the overall effectiveness of the catalyst. These effects are either of a mechanical or a chemical nature. High temperatures reduce the active area by causing the noble metals to agglomerate and sinter whereas the additives alter the activity by either fouling the pores of the support material (phosphorus) or by interacting with the metals (sulphur and lead).</p><p>The main objective of this work was to develop a method to redisperse the catalytically active sites, comprising Pd, Pt and Rh on the washcoat surface, in an effort to regain lost catalyst activity. For this purpose, a wide spectrum of different commercial car exhaust catalysts containing varying noble metal loadings, aged under various driving conditions and with mileages ranging from 30 to 100 000 km were evaluated.</p><p>The influence of a thermal treatment in a controlled gas atmosphere, such as oxygen or hydrogen and a redispersing agent, e.g. chlorine, on the activity of TWC was investigated by means of laboratory-scale activity measurements. Several complementary characterisation methods such as SEM/TEM, XRD, BET and TPR were used to verify the effects of the regeneration treatments on the catalyst morphology (Paper I). Partial regeneration of catalyst activity and noble metal dispersion was achieved after thermal treatment in an oxygen-chlorine rich atmosphere at temperatures below 500 °C.</p><p>Finally, an investigation of the effects of an oxy-chlorine thermal treatment for regeneration of a ‘full-scale’ commercial automotive three-way catalyst was performed. Catalyst activity and performance prior to and after the oxy-chlorine thermal treatment was measured on a test vehicle in accordance with the European driving cycle (EC2000). The catalyst surface was further characterised using XRD and EDX (Paper II). Improved catalyst activity for a high mileage catalyst could be observed, with emissions lowered by approximately 30 to 40 vol% over the EC2000 driving cycle</p>

In this work I have evaluated a measurement method for glucose concentration in aqueous solutions and developed a system that performs the measurement and presents the result on a computer screen. The method is based on the dielectric properties of glucose and the varying phase shift of a microwave resonance cavity. The phase shift is measured using homodyne detection. The measurement system can measure the concentration of glucose in aqueous solutions in real time. I have tested concentrations from 0 to 3000 mg/dl. / I detta arbete har jag undersökt en metod för att mäta glukoskoncentration och med denna metod konstruerat en mätutrustning som visar glukoskoncentrationen för ett prov på en datorskärm. Mätningen baseras på radiovågor och permittiviteten för glukoslösningar. För att mäta permittiviteten används en mikrovågsresonanskavitet och homodyn detektering. Det gör det möjligt att mäta även mycket små prov, och detta utan att vara i direkt kontakt med provet. Mätsystemet kan mäta koncentrationen på vattenlösningar av glukos i realtid. Jag har testat systemet på koncentrationer mellan 0 och 3000 mg/dl.

Health technology or e-Health is one of the most rapidly growing areas in healthcare today and it has been an important requirement as a new concept of healthcare industry. Since global society has been changed to aging society and the healthcare cost has been increasing in the 21st century since 2007. As the total number of people aged 65 or older is expected to increase from 12% to 22% in 2050 which is double the rate, and at the same time there is a decrease in in-fertility rates and increase in life expectancy due to the increase in life quality, there is a need to investigate the needs and requirements of an intelligent embedded sensor systems in health applications, and to develop a new communication protocol or set of protocols that can be used to send data collected from a hub within a house, home-care or a complex and send it securely and reliably to a central database where the gathered data can be monitored by a medical professional to make decisions for further interventions. The employed communication protocol should also be able to securely transmit confidential parameters from the hospital network to a central server outside of the hospital network. The final protocol must be inline with the regulations of the EU. This thesis is done in collaboration with Tjeders AB, Stille AB, and Embedded Sensor Systems for Health Plus (ESS-H+) research profile at Mälardalen University. In this thesis, different communication protocols such as IPSec and TLS and algorithms such as AES and RSA are examined and based on the requirements provided by the companies certain of these protocols and algorithms will be used in the final implementation. Different performance metrics such as overhead, round trip delay and throughput will be measured for the chosen communication protocols and recommendations will be given on which of the protocols and algorithms needs to be used to obtain an optimized, secure and reliable network.

The 1-wire bus is a communication bus system which is designed to provide data, signals and power over a single signal with low data rates, a high resolution and a long range. It is typically used to communicate with small inexpensive devices, as temperature sensors, which is worked as a slave with the master computer (PC). The 1-wire bus system provides the sufficient control and operation signal, a unique ID serial number of each sensor and it supports multiple temperature sensors by a driving power (Parasite Power) on single line. On the 1-Wire bus system, temperature sensors are supplied by two types of power supplies, external Power supply and Parasitic Power. The aim of this project is to program the microprocessor (Arduino) by using Arduino programming language to work as a temperature sensor type DS18B20 and also as a slave on the 1-Wire bus system. This report explains the 1-Wire bus system techniques and how the communication is achieved between the master and the slave (sensors) to measure the temperature values. The measured temperature values are collected from the output of each active sensor on the 1-Wire bus. These data are displayed by the personal computer (PC) which is worked as a master on the 1-Wire bus, and the data are represent the measured temperature values from twelve active sensors on the bus system. In this thesis, the temperature values from the 12 active sensors can be read and displayed on the master (PC) by using the following programs: Open Logger One Wire (OLOW) program, One Wire Viewer, DigiTemp and OWFS and I validated all the temperature values from these active sensors which are read and monitored by the drive bus programs. The comparison is done among the measured temperature values to see if the active sensors are given accurate temperature values with different drive bus programs. The project shows that the sensors can be connected in a network with the master, by using 1-Wire bus techniques. This thesis will be used by Karolinska University Hospital, and it can also be developed for different requirements in the future.

The Leksell Gamma Knife® (LGK) is a device for performing radiosurgery. The LGK contains approximately 200 radioactive sources whose beams intersect in a focal point in order to treat brain tumours. Quality assurance tools are used at Elekta to indirectly assess the number of sources in an LGK from the total amount of radiation. In order to increase patient safety, regulatory agencies have been asking for evidential proof of the number of sources in the LGK. This thesis' goal is to directly measure each source in the LGK and optimize the total detection time. To do this, a source detection system was developed with two parts, a radiation detection system and a moving gantry. Initial tests of the design were performed at Elekta and a final test was performed on an LGK at Karolinska Universitetssjukhuset. The results show that the proposed design has the possibility of detecting all sources in an LGK.

Apple WatchTM huserar funktionaliteter inom medicinteknik. Detta är ett examensarbete inom medicinteknik som ställer frågan om hur pass bra mätningar den utför i förhållande till motsvarande medicinteknisk produkt. Smartklockan kan identifiera R-toppar i EKG mycketväl, och därigenom också förmaksflimmer. I förhållande till pulsoximeter presenteras syremättnad några procentenheter för högt och följsamheten är något stel. Apple WatchTM mäter puls bra vid högre hjärtslagsfrekvenser, men har kraftigt begränsad träffsäkerhet och sämre följsamhet vid mätningar i vila. Det kan inte styrkas att Apple WatchTM kan användas som verktyg för att ställa någon medicinsk diagnos, utifrån testerna i detta arbetet, där datamängd och urvalsgrupp samtidigt varit för liten för att kunna ge riktig statistisk signifikans. / The Apple WatchTM has functionalities related to the field of medical technology. This is a degree project in medical engineering that raises the question how adequate measurements it can acquire, in relation to a corresponding medical device. The Apple WatchTM can identify R waves in ECG very well and thereby also atrial fibrillation. In relation to pulse oximeters, oxygen saturation is given a few percentage points too high and the compliance is somewhat rigid. Apple WatchTM measures heart rate well at higher heart rates, but has severely limited accuracy and has poorer compliance when measuring at rest. The tests of this work shows that the Apple WatchTM should not be used as a tool for making any medical diagnosis, but the amount of data and test subjects were not sufficient enough to make it statistically significant.

Roughly 123 million people worldwide are affected by conditions such as epilepsy, dementia, and cardiovascular diseases. Wearable electrodes are currently used to monitor these conditions short-term. Long-term monitoring would allow for predicting seizures and could be used as a preventive treatment. As opposed to the currently used electrodes, wearables that are intended for long-term use must be soft and flexible in order not to cause harm or discomfort for the user. The electrodes should also have high resolution, meaning that the electrode paths should be as narrow as possible without negatively affecting the performance of the electrode. In this thesis, soft and flexible electrode grids based on silicones are developed using UV laser patterning. Two different methods are evaluated: laser curing of silicones with the addition of a photoinitiator, and laser ablation of conductive composite. The results found in this thesis are that photocuring silicones gives a too low resolution to be useful for patterning soft electrode grids. UV laser ablation on the other hand showed high resolution while the electrodes retained stretchability. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>