<p>The presence of clustered micro-calcifications is an important indicator of early stage breast cancers, and an efficient real-time ultrasound imaging support is needed for conducting needle biopsies. SURF is a dual-frequency band ultrasound technique capable of imaging nonlinear scattering using the superposition of a low-frequency pulse to manipulate the tissue characteristics and an imaging pulse to extract the informations. This new technique has already demonstrated its superiority in imaging high intensity nonlinear scatterers like ultrasound contrast agents compared to the classical methods. However, imaging lower intensity nonlinear scatterers like micro-calcifications requires the use of higher manipulation pressures, causing the apparition of complex distortions of the imaging pulse neglected hitherto. In order to achieve a sufficient level of tissue suppression and detect the micro-calcifications using SURF imaging, these nonlinear forward propagation effects must be characterized and corrected for. In this thesis, simulations have been conducted based on the geometry of the first manufactured prototypes of SURF probes, named Viglen and Okla. The nonlinear propagation effects were described as the regroupment of a nonlinear propagation delay due the average level of LF manipulation pressure experienced by the HF pulse, a mix of compressions/expansions of the imaging pulse resulting from the fluctuations of the LF manipulation pressure over the HF pulse, and a phenomenon of SURF aberration due to the difference in the focusing and diffraction pattern of the HF and LF beams. The build-up of these nonlinear propagation effects were shown to be fully characterized by the combination of the profiles of the LF beam and the phase-relation between the two pulses. The different beamforming strategies, with the superposition of a focused HF beam on a plane or co-focused LF beam, were also discussed: a net trade-off appears between the minimization of delays and SURF aberrations ensured by the co-focal configurations, and the minimization of compressions/expansions effects by using plane LF beams. A strategy to limit the nonlinear propagation effects would be the use of an especially designed transducer providing an excellent HF focusing in the study range and a sufficiently large LF aperture. A filter was then designed and tested to ensure a correction of the pulse-form distortions in the received signals. The filter improved the level of suppression of the linear scattering from tissue by 15 dB in the numerical simulations, allowing a theoretical detection of the micro-calcifications and raising the resolution of the imaging system up to 1 dB close to the noise floor. The same filter demonstrated a smaller suppression of only 7 dB with the experiments conducted on phantoms, 2 dB below the limit required for detecting the smallest micro-calcifications. Further work studying the pulse-form correction filter should be conducted to understand this difference in performances, along with a real-time implementation on the scanner, before achieving a correct detection of micro-calcification using SURF imaging.</p>

<p>High quality images with strong contrast, good resolution and geometrical consistency are of crucial importance in magnetic resonance imaging, where the relatively low intrinsic sensitivity of MR methods places high demands on the imaging hardware. One of many key components in the imaging system is the radiofrequency coil, responsible for transmitting excitation signals and/or listening for response from the object. In this project a number of such coils are developed for specific applications (namely proton imaging of rat and fish brains), then evaluated against phantoms and empirically in simulated imaging situations. Evaluation of the produced coils shows promising initial results, with various opportunities for further refinement into a device suitable for regular use.</p>

Norsk Forening for Automatisering endret i 2009 sin visjon til ?Gjøre automatiseringtil et hovedtema i det offentlige rom.? Formålet med NFA-grillener å fremme visjonen om å gjøre automatisering til et hovedtema i det offentligerom. Det skal foregå ved å lage en automatisert pølsegrill som skaldoneres til TV-aksjonen.Oppgaven ledet frem til et ferdig produkt med dertilhørende valg av delsystemog teknologier. For å forsikre et best mulig resultat ble det utført enlitteraturstudie i forkant av det praktiske arbeidet.Arbeidet er utført ved hjelp av to ?underleverandører?, Arbeidsgruppe 6 iEksperter i Team-landsbyen ?Byggelandsbyen? og verkstedet ved Institutt forteknisk kybernetikk. Eksperter i Team-gruppa leverte reflektoren til grillenog verkstedet bidro med maskineringen av selve grillen.Det ble innhentet ekspertise fra Forskningssenteret for Miljøvennlig Energifor solcelleteknologi, ved Institutt for energiteknikk for produksjon av spesialtilpassetsolcellepanel til å produsere strøm til å drive aktuatorer og elektronikk.Som solfølgingsmetode ble det valgt å bruke GPS for å innhente posisjonsogtidsdata. Disse ble deretter brukt i en algoritme, SOLPOS utviklet avNREL, til å beregne solvektoren. For å vite grillens orientering ble et tilkompensertkompass med innebygget aksellerometer benyttet. Referansedata fraSOLPOS-algoritmen og måledata fra kompasset ble deretter benyttet i enreguleringsprosedyre som ved hjelp av to aktuatorer retter grillen mot sola.Det resulterende produktet fungerte etter formålet og oppnådde en nøyaktighetpå 0,8 grader som er innefor kravet som ble satt til én grad.

Shell Eco-marathon er en årlig internasjonal bilprototype-konkurranse mellom studentlag fra høyskoler og universiteter. Våren 2010 skal NTNU delta for 3. gang. Denne oppgaven går ut på å spesifisere krav, designe, lage og teste et komplett instrumenteringssystem for eco-marathon-bilen som deltar i konkurransen i 2010. Modulær oppbygning, samt velprøvd kommunikasjon basert på CAN-bus mellom moduler, danner grunnlaget for et stabilt og enkelt rekonfigurerbart system.Flere delkomponenter som ble benyttet i bilen foregående år, fungerte ikke ved overtakelse av bilen høsten 2009. På grunn av problemene med tidligere system, kombinert med ønsket om toveis kommunikasjon med alle moduler i bilen, ble det besluttet at et helt nytt system skulle utarbeides. Bilens instrumenteringssystem består i hovedsak av brenselcelleovervåkning og styring, kommunikasjon med en el-motordrift, brukergrensesnitt for sjåføren, utvendige lys og signalhorn.Brenselcellestyringen består av en galvanisk isolert måleløsning for individuelle cellespenningsmålinger, soneinndelt temperaturovervåkning, måling av hydrogentrykk og styring av hydrogenventiler, samt et sikkerhetssystem med automatisk avstengning ved gasslekkasje.Forskjellige måter å løse problemet med cellespenningsmålinger er undersøkt. Et fleksibelt og kompakt system er designet og implementert som håndterer funksjonene nevnt ovenfor.Utvendige lys på bilen med tilhørende driverkretser er basert på energieffektive og kraftige lysdioder som både har mulighet til å lyse opp veien foran bilen, og justeres ned i lysstyrke for å spare strøm. Alt kan enkelt betjenes via et menysystem på en lcd-skjerm i dashbordet. Et utvidbart og fleksibelt menysystem er implementert for å håndtere innstillinger og informasjon fra bilens systemer.Ettersom systemet er modulbasert, og hver CAN-bus-modul igjen er modulbasert, er det enkelt å rekonfigurere eller endre funksjonaliteten til systemet eller delmoduler. Å hekte på nye moduler for ny funksjonalitet er også veldig enkelt. Systemet kan også benyttes i andre sammenhenger enn bil-instrumentering. Brenselcellemodulen ble for eksempel benyttet på lab hele våren for test og utvikling av styringsalgoritmer for brenselcellestacken. Eksempler på andre bruksområder for deler av systemet kan være hus-automasjon eller styring og overvåkning av andre slags lab-oppstillinger.Selv om konkurranseresultat uteble på grunn av problemer med motorstyringen har elektronikken i styringssystemet stort sett fungert veldig bra under hele prosjektperioden. Det er gjort gode erfaringer med design og bestilling av profesjonelt produserte kretskort, samt innkapsling av elektronikk for å tåle røff håndtering og miljøpåvirkninger. Der problemer har oppstått, spesielt med kretsløsning og de integrerte kretsene benyttet for spenningsmåling på brenselcellestacken, er det nevnt hva som sannsynligvis er skyld i problemene og hva som kan gjøres med det.

<p>AVR32 is a new processor architecture made by Atmel Norway, and in this thesis it has been used to make a control system platform. The hardware used in this platform is the STK1000, an AVR32 development board and an I/O-card. The I/O-card were developed as a part of the thesis. Software for the platform consists of I/O-card firmware, Linux device driver for the I/O-card and user mode drivers. The platform supports usage of Matlab Real-Time Workshop as a rapid prototyping tool, that generates code from graphical visualization of mathematical models. S-functions were created so Matlab Real-Time Workshop can control the I/O-card. The control system platform is documented in an user manual. This manual describes how to install development tools for the platform on a Linux or Windows computer, and how to use the it.</p>

<p>This thesis discusses the implementation of ultrasound beamforming on the GPU using CUDA. Fractional delay filters and the need for it when implementing beamforming is discussed. An introduction to CUDA programming is given as well as a study of the workings of the NVIDIA Tesla GPU(or G80). A number of suggestions for implementing beamforming on a GPU is presented as well as an actual implementation and an evaluation of it's performance.</p>

<p>This report considers the work to improve the autonomy of surgical teleoperated systems, by introducing haptic guidance. The use of surgical robots in surgical procedures have become more common the recent years, but still it is in its infancy. Some advantages when using robots is scalability of movements, reduced tremor, better visualisation systems and greater range of motions than with conventional minimally invasive surgery. On the contrary, lack of tactile feedback and highly unstructured medical environment restricts the use of teleoperated robots to specific tasks within specific procedures. A way of improving autonomy of the teleoperated system is to introduce predefined constraints in the surgical environment, to create a trajectory or forbidden area, in order to guide the movements of the surgeon. This is often called haptic guidance. This report introduces the basics of teleoperated systems, with control schemes, models and analytical tools. Algorithms for haptic guidance have been developed, and the entire control and guidance system have been modified and suited for implementation on a real teleoperated system. Theoretical analysis of the position position (PP) control scheme reveals some general stability and performance characteristics, later used as a basis for tuning the real system parameters. The teleoperated system consists of a Phantom Omni device, from SensAble-Technologies, used as master manipulator, and AESOP 3000DS, from Computer Motions Inc., as the slave manipulator. The control system is implemented on a regular PC, connecting the complete system. Tests reveal that the slave manipulator is not suited for this task due to a significant communication time delay, limited velocity and inadequate control possibilities. The consequences makes force feedback based on the PP control scheme impossible, and limits performance of the entire teleoperated system. The guidance system is implemented in two variations, one based on slave positions and one based on master positions. This is motivated to give a performance comparison for variations of position error/tracking between the two manipulators. Slave based guidance appears to be stable only for limited values of the gains, and thus, it generates no strict constraints. It can be used to guide the operator away from forbidden areas, but is not suitable for high precision guiding. The master based guidance is stabile for very high gains, and the guidance have the accuracy to improve the surgeons precision during procedures. In the case of line guidance, the master based guidance gives a deviation of up to $1.3mm$ from the given trajectory. The work has shown the possibilities of using haptic guidance to improve accuracy and precision in surgical procedures, but among others, hardware limitations give room for several improvements in order to develop a teleoperated system that works.</p>

<p>This thesis presents segmentation of the right ventricle of the heart in real-time tracking of 3D ultrasound recordings. A simple deformable model for the right ventricle is developed based on statistical data from manual segmentations, and the model has been tested out in a set of 3D ultrasound recordings and compared to manually segmented right ventricular volumes. The manual segmentation method with volume approximation is also developed. The segmentation tests on the recordings are performed with an already present Kalman filter based real-time contour tracking framework. The ability of the models to fit to the shape of the right ventricle has been evaluated, and the resulting volume curves have been inspected. Deformable models of the right ventricle are constructed by placing nodes in an initial three-dimensional mesh, and subdivision schemes are applied to make smooth surfaces. There have also been experimented with models of different resolutions and initial positions. A background study of right ventricular anatomy, subdivision, model-based segmentation and Kalman filter theory is included, and clinical applications of volume measurements in real-time are suggested. The results of the segmentation are promising, and indicate that models adjust to the right ventricle during the heart beat.</p>

<p>To enable deterministic scheduling in a distributed embedded system an existing open source embedded TCP/IP stack has been modified to support strict priority queuing. The embedded target system has a fully switched closed Ethernet backplane used for internal communication. The problem is that high-volume configuration file downloads interfere with low-volume internal signaling, such as alarms, status reports, performance data and other statistics. The network was already designed using a type of switches which could support several Quality of Service schemes. An open source embedded TCP/IP stack, lightweight IP (lwIP) was evaluated, and found to be a suitable foundation for the developed application; the Priority Based Message Stack (PBMS). PBMS is a modification of lwIP with support for selective packet forwarding and reception based on the IPv4 Type-of-Service (TOS) field. Support for the BOOTP protocol, as well as a nonblocking send operation, was also implemented. PBMS is easily portable in the sense that it only requires a clearly defined basic set of generic OS functions in order to be ported to new systems. A generic interface to Ethernet drivers must also be developed. The implementation was desktop tested on a Linux platform for correct functionality in the IP, UDP and BSD Socket modules. The performance of the priority scheme compared to a best-effort strategy was also measured. These tests showed that stack-internal strict prioritization based on the IPv4 TOS precedence bits have a clear potential for offering deterministic transfer times in Nera’s distributed embedded system. Without prioritization, with contention for the network link, an average output time of 480 microseconds was measured from the time the socket sendto function was called until the IP output function had been executed. Using strict prioritization under the same conditions this sequence of functions executed in only 15 microseconds in 99 percent of the test runs. The proper prioritization within the TCP/IP stack is only one of several queuing points in the target network. The existing switches, along with the proper TOS marking of each packet, will ensure an unbroken chain of priority queueing all the way to the destination. Some network endpoints might have variable latencies, which will affect the round-trip time (RTT). A measurement methodology to determine this has been described. A test methodology for round-trip and one-way delay time measurement will be used to validate PBMS in the target system. These tests can also be used to estimate the latencies in those network endpoints mentioned above. With this data at hand a worst-case RTT for the entire system can be calculated. The target system integration and validation will be carried out immediately after the completion of this thesis.</p>

<p>Design and implementation of a multicore scheduler for the Linux kernel. Specifically look at the pfair global algorithm, a ratebased deadline driven scheduler that is near-optimal on multicore platforms</p>