A Front-end to LBTest for Conformance Testing of Embedded Systems

This report presents the work creating and evaluating a front-end for conformance testing with the LBTest software and the viability of a tool of this kind. LBTest is a tool designed for learning-based testing of embedded systems using model checking. In order to reach a verdict the model checking uses a specification written in linear temporal logic. The front-ends desired functionality is to translate NuSMV-files into linear temporal logic. A .dot-file should also be generated in order to render a visual representation of the Nu- SMV-file. A case study where the front-end translates a model's specification and testing it on a program with LBTest is successful and shows that a frontend is possible to create and use in order to achieve conformance testing in LBTest.Den här rapporten beskriver arbetet för att skapa och utvärdera en front-end för testningsprogramvaran LBTest och hur användbart ett sådant verktyg är för att använda sig av conformance testing. LBTest använder learning-based testing för att lära sig hur inbyggda system är uppbyggda genom att använda model checking. Det slutgiltiga front-end programmet ska översätta modellspecifikationer skrivna i NuSMV till linear temporal logic som är det logikspråk som LBTest använder sig av. Även en .dot-fil ska skapas som kan användas till att rendera en grafisk representation av modellspecifikationen. En fallstudie av programmet där en modellspecifikation översätts och körs i LBTest visar att mjukvara av den här typen går att skapa och är en lämpligt verktyg för att uppnå conformance testing med LBTest

Publisher correction: Indication of Thalamo-Cortical Circuit Dysfunction in Idiopathic Normal Pressure Hydrocephalus : A Tensor Imaging Study

Correction to: Scientific Reports https://doi.org/10.1038/s41598-020-63238-7</p

Indication of Thalamo-Cortical Circuit Dysfunction in Idiopathic Normal Pressure Hydrocephalus : A Tensor Imaging Study

Idiopathic normal pressure hydrocephalus (iNPH) is a disorder with unclear pathophysiology. The diagnosis of iNPH is challenging due to its radiological similarity with other neurodegenerative diseases and ischemic subcortical white matter changes. By using Diffusion Tensor Imaging (DTI) we explored differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in iNPH patients (before and after a shunt surgery) and healthy individuals (HI) and we correlated the clinical results with DTI parameters. Thirteen consecutive iNPH-patients underwent a pre- and post-operative clinical work-up: 10m walk time (w10mt) steps (w10ms), TUG-time (TUGt) and steps (TUGs); for cognitive function MMSE. Nine HI were included. DTI was performed before and 3 months after surgery, HI underwent DTI once. DTI differences analyzed by manually placing 12 regions-of-interest. In patients motor and balance function improved significantly after surgery (p=0.01, p=0.025). Higher nearly significant FA values found in the patients vs HI pre-operatively in the thalamus (p=0.07) accompanied by an almost significant lower ADC (p=0.08). Significantly FA and ADC-values were found between patients and HI in FWM (p=0.02, p=0.001) and almost significant (p=0.057) pre- vs postoperatively. Postoperatively we found a trend towards the HIs FA values and a strong significant negative correlation between FA changes vs. gait results in the FWM (r=-0.7, p=0.008). Our study gives a clear indication of an ongoing pathological process in the periventricular white matter, especially in the thalamus and in the frontal white matter supporting the hypothesis of a shunt reversible thalamo-cortical circuit dysfunction in iNPH.Funding Agencies|Linkoping University</p

Laparoscopic distal pancreatectomy is more cost-effective than open resection: results from a Swedish randomized controlled trial

Background Laparoscopic distal pancreatectomy is being implemented worldwide. The aim of this study was to perform a cost-effectiveness analysis from a health care perspective. Methods This cost-effectiveness analysis was based on the randomized controlled trial LAPOP, where 60 patients were randomized to open or laparoscopic distal pancreatectomy. For the follow-up of two years, resource use from a health care perspective was recorded, and health-related quality of life was assessed using the EQ-5D-5L. The per-patient mean cost and quality-adjusted life years (QALYs) were compared using nonparametric bootstrapping. Results Fifty-six patients were included in the analysis. The mean health care costs were lower, €3863 (95% CI: -€8020 to €385), for the laparoscopic group. Postoperative quality of life improved with laparoscopic resection and resulted in a gain in QALYs of 0.08 (95% CI: −0.09 to 0.25). The laparoscopic group had lower costs and improved QALYs in 79% of bootstrap samples. With a cost-per-QALY threshold of €50 000, 95.4% of the bootstrap samples were in favour of laparoscopic resection. Conclusion Laparoscopic distal pancreatectomy is associated with numerically lower health care costs and improvements in QALYs compared with the open approach. The results support the ongoing transition from open to laparoscopic distal pancreatectomies