Necessary and sufficient condition for the global stability of a delayed discrete-time neuron model

Positron emission tomography (PET) studies acquired in list mode offer the opportunity to provide a cine loop showing the dynamics of 18F- PET uptake, giving a visualization of regional bone remodeling. The focus of this report is a group of patients treated with Taylor spatial frames (TSF). The studies were acquired for a period of 45 minutes and saved in list mode. The list was decoded and subsequently segmented into time intervals of one minute each. For each time interval a sinogram was generated from which volumes of one minute each were reconstructed. Slices projected from these volumes could then be displayed as a dynamic loop superimposed on the corresponding computed tomography (CT) slice in order to visualize the 18F- uptake insitu. It was indicated that this technique has the potential of becoming an additional technique to that of using static volumes and SUV values only. As the list mode data was decoded it also offered a method to evaluate the potential decrease in injected activity by eliminating every Nth event from the list before reconstructing the 45 minute volume. This was done and the indication was that the injected activity and hence the effective dose to the patient can be decreased. However, in this work, this was not proven clinically. The open source STIR software was used to reconstruct volumes from sinograms to enable an unlimited access to reconstructing volumes without disturbing the daily routine at the clinic. The data was acquired on a clinical Siemens Medical Solutions Biograph 64 TruePoint TrueV, PET/CT scanner situated at the Nuclear Medicine Department at the Karolinska University Hospital in Solna. This scanner was not supported by the STIR software, hence the data collected by the Siemens PET/CT scanner was translated so that 3D reconstructions could be computed using the STIR tools. The reconstructions made in STIR resulted in volumes of sufficient visual quality, but not as good as those reconstructed by the scanner itself. Further optimization in STIR was left for future work. According to the physicians who treat these patients, dynamic visualization was of sufficient interest to continue to develop and optimize this method. The cine loops that were presented to the physicians were made from JPEG slices produced from the one minute volumes and put together as GIF files. It was also possible to vary the reconstruction time (from uniformly one minute) as well as the presentation rate in the cine loop, but this was left for future work. Ultimately, the cine loop will be implemented in the locally developed software tool.Positronemissionstomografi (PET) studier som förvärvats i list mode erbjuder möjligheten att göra film slingor som visar dynamiken i 18F- PET upptag. Detta förväntas ge en dynamisk visualisering av var ben nybildas. Fokus i denna rapport är en grupp patienter som behandlats med Taylor spatial frames (TSF). Bilderna i studien förvärvades under en period av 45 minuter och sparades i list mode. List mode data avkodades och delades därefter upp i tidsintervaller på en minut vardera. För varje tidsintervall rekonstruerades ett sinogram för vilka bilder av volymen rekonstruerades. Skivor från dessa volymer kan sedan visas som en dynamisk slinga ovanpå motsvarande datortomografi (CT) skiva för att visualisera 18F- upptaget in situ. Denna teknik visade sig ha potential att bli en ytterligare teknik utöver de statiska volymer och SUV-värden som redan finns tillgängliga. Eftersom listmode data avkodats erbjuds också en metod för att utvärdera en potentiell minskning av den injicerade aktivitet genom att eliminera varje N: te händelse från listan innan volymen på 45 minuter rekonstrueras. Detta utfördes och det visade sig att den injicerade aktiviteten och därmed den effektiva dosen till patienten potentiellt kan minskas men i detta arbete har detta inte bevisats kliniskt. Mjukvaran STIR, som är tillgängligt för allmänheten, användes för att rekonstruera volymer från sinogram för att möjliggöra en obegränsad tillgång till att rekonstruera volymer utan att störa den dagliga rutinen på kliniken. Data förvärvades i en klinisk Siemens Medical Solutions Biograph 64 TruePoint TrueV, PET/CT-skanner som är placerad vid nuklearmedicinska avdelningen vid Karolinska Universitetssjukhuset i Solna. Skannern var inte kompatibel med STIR mjukvaran. Därför översattes det data som samlats in av Siemens PET/CT-skannern så att 3D-rekonstruktioner kan beräknas med hjälp av verktygen i STIR. De rekonstruktioner som gjorts i STIR gav upphov till volymer av tillräcklig visuell kvalitet för denna studie, men var inte lika bra som de som rekonstrueras genom själva skannern. Ytterligare optimering i STIR lämnades för framtida arbete. Enligt de läkare som behandlar dessa patienter var en dynamisk visualisering av tillräckligt intresse att fortsätta utveckla och optimera den här metoden. Film slingor som presenterades för läkarna gjordes från JPEG bilder tagna från skivor av volymer på en minut vardera som producerats och sattes ihop som GIF-filer. Det var också möjligt att variera återuppbyggnadstiden (från jämnt en minut) samt presentationshastigheten i film slingan, men detta lämnades till framtida arbetet. I slutändan kommer film slingan implementeras i ett lokalt utvecklat verktyg.QC 20151102</p

A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis

As the most advantageous total hip arthroplasty (THA) operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT) volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD) of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (±SD) for the diameter of the acetabular cup of 54.21 (±0.011) mm and for the femoral component head of 22.09 (±0.02) mm. The wear error was ±0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction

FMM-Head: Enhancing Autoencoder-based ECG anomaly detection with prior knowledge

Detecting anomalies in electrocardiogram data is crucial to identifying deviations from normal heartbeat patterns and providing timely intervention to at-risk patients. Various AutoEncoder models (AE) have been proposed to tackle the anomaly detection task with ML. However, these models do not consider the specific patterns of ECG leads and are unexplainable black boxes. In contrast, we replace the decoding part of the AE with a reconstruction head (namely, FMM-Head) based on prior knowledge of the ECG shape. Our model consistently achieves higher anomaly detection capabilities than state-of-the-art models, up to 0.31 increase in area under the ROC curve (AUROC), with as little as half the original model size and explainable extracted features. The processing time of our model is four orders of magnitude lower than solving an optimization problem to obtain the same parameters, thus making it suitable for real-time ECG parameters extraction and anomaly detection.Comment: 23 pages, 14 figure

Sagor, visor och lekar

Skyddsengelns röst ; Fjäderholmarna ; Prinsessan Lindagull ; Alanda cantat ; Refanut ; Skolgossarnes segersång ; Matts Lustigs barn ; Tidningssättaren vid sin stilkast ; Fattig-gubben ; Aftonvandring ; Georgs konungariken ; Ångbåtseldaren ; Lasse liten ; Svarta hafvets matros ; Tändstickan ; En vårdag på Finska Viken ; Pehr Matts' sten ; Jernvägskonduktören ; Myran, som for till doktorn ; Telegrafisten ; Lilla Genius ; Vaggvisa för en nordanstorm ; Stjernöga ; Vid postluckan för ankommande bref ; Myreborg och Gråmossa ; Johanna d'Arc ; Sikku ; Berndt Michaels dröm ; Det vissnade löfvet ; Hvar få vi en julgran? ; Måne klara ; Ängens söndagsmorgon

A Graphical Workstation and Programming Environment for Data-Driven Computation

This dissertation reports on the development of a prototype programming environment for a graphical programming language to support a data-driven style of computation. Emphasis is on the need for tools to assist in the development of nontrivial graphical programs. Within the scope of programming languages there has been a lot of criticism that the current languages force an unnatural form for solutions, which is difficult to read, and even harder to verify, debug, maintain, and modify. One of the major "culprits" for all of these problems is felt to be side effects; thus there have been several proposals to create functional languages. One class of functional solutions which has received an increasing amount of interest is the area of data flow languages. In order to evaluate these alternate programming methodologies nontrivial programs need to be developed using such a methodology. This work grew out of an interest in providing a programming environment to support the development of very large programs in GPL and to find out what aspects of a programming environment would be substantially different for a graphical language which employs a data-driven computational model.1983; 752498871; Maguire, Gerald Quentin, Jr; 8313153; 26551011; 303280688; Copyright UMI - Dissertations Publishing 1983; 66569; English; 128 p.; M1: Ph.D.; M3: 8313153. QC 20120120</p

PIP-1: A Personal Information Portal with wireless access to an information infrastructure

We discuss our ideas for the Personal Information Portal its hardware and software platform our visions for its use and its impact on the student and the professional community.Qc 2012022

PIP-1: A Personal Information Portal with wireless access to an information infrastructure

We discuss our ideas for the Personal Information Portal its hardware and software platform our visions for its use and its impact on the student and the professional community.Qc 2012022

The Coherent Trivial File Transfer Protocol

CFDP is a protocol that takes advantage of the broadcast nature of CSMA networks to speed up simultaneous one-to-many file transfers (e.g., when booting diskless workstations). The CFDP server listens and services requests for entire files or portions thereof. CFDP clients first determine whether the file they are interested in is already being transferred, in which case they "eavesdrop" and load as much of it as they can or they initiate a new transfer. The clients timeout when the server stops transmitting and if they are still missing parts of the file they request them with a block-transfer request. CFDP is a back-end protocol a front end is needed to handle naming and security issues. A simple such front end is also presented here.This later became internet RFC 1235.QC 2012022