| 1. |
- Spühler, Jeannette Hiromi, 1981-, et al.
(författare)
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A High Performance Computing Framework for Finite Element Simulation of Blood Flow in the Left Ventricle of the Human Heart
- 2020
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Ingår i: Lecture Notes in Computational Science and Engineering. - Cham : Springer. ; , s. 155-164
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Konferensbidrag (refereegranskat)abstract
- We present a high performance computing framework for finite element simulation of blood flow in the left ventricle of the human heart. The mathematical model is described together with the discretization method and the parallel implementation in Unicorn which is part of the open source software framework FEniCS-HPC. We show results based on patient-specific data that capture essential features observed with other computational models and imaging techniques, and thus indicate that our framework possesses the potential to provide relevant clinical information for diagnosis and medical treatment. Several other studies have been conducted to simulate the three dimensional blood flow in the left ventricle of the human heart with prescribed wall movement. Our contribution to the field of cardiac research lies in establishing an open source framework modular both in modelling and numerical algorithms.
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| 2. |
- Isaksson, Johan, et al.
(författare)
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Audomni : Super-Scale Sensory Supplementation to Increase the Mobility of Blind and Low-Vision Individuals - A Pilot Study
- 2020
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Ingår i: IEEE Transactions on Neural Systems and Rehabilitation Engineering. - 1534-4320. ; 28:5, s. 1187-1197
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Blindness and low vision have severe effects on individuals' quality of life and socioeconomic cost; a main contributor of which is a prevalent and acutely decreased mobility level. To alleviate this, numerous technological solutions have been proposed in the last 70 years; however, none has become widespread. Method: In this paper, we introduce the vision-to-audio, super-scale sensory substitution/supplementation device Audomni; we address the field-encompassing issues of ill-motivated and overabundant test methodologies and metrics; and we utilize our proposed Desire of Use model to evaluate proposed pilot user tests, their results, and Audomni itself. Results: Audomni holds a spatial resolution of 80 x 60 pixels at 1.2° angular resolution and close to real-time temporal resolution, outdoor-viable technology, and several novel differentiation methods. The tests indicated that Audomni has a low learning curve, and several key mobility subtasks were accomplished; however, the tests would benefit from higher real-life motivation and data collection affordability. Conclusion: Audomni shows promise to be a viable mobility device - with some addressable issues. Employing Desire of Use to design future tests should provide both high real-life motivation and relevance to them. Significance: As far as we know, Audomni features the greatest information conveyance rate in the field, yet seems to offer comprehensible and fairly intuitive sonification; this work is also the first to utilize Desire of Use as a tool to evaluate user tests, a device, and to lay out an overarching project aim.
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| 3. |
- Isaksson, Johan, et al.
(författare)
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Desire of Use : A Hierarchical Decomposition of Activities and its Application on Mobility of by Blind and Low-Vision Individuals
- 2020
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Ingår i: IEEE Transactions on Neural Systems and Rehabilitation Engineering. - 1534-4320. ; 28:5, s. 1146-1156
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Blind and low-vision individuals often have severely reduced mobility, affecting their quality of life and associated socioeconomic cost. Despite numerous efforts and great technological progress, the only used primary mobility aids are still white canes and seeing-eye dogs. Furthermore, there is a permeating tendency in the field to ignore knowledge of both mobility and the target group, as well as constantly design new metrics and tests that makes comparisons between solutions markedly more difficult. Method: The Desire of Use model is introduced in an effort to promote a more holistic approach; it should be generalizable for any activity by any user, but is here applied on mobility of blind and low-vision individuals by a proposal and integration of parameters. Results: An embodiment of the model is presented and with it we show why popular mobility metrics of today are insufficient to guide design; what tasks and metrics that should provide better understanding; as well as which fundamental properties determine them and are critical to discuss. Conclusion: Desire of Use has been introduced as a tool and a theoretical framework, and a realization has been proposed. Significance: Desire of Use offers both a structured perspective of pertinent design challenges facing a given solution, as well as a platform from which to compare test results and properties of existing solutions; in for example the field of electronic travel aids it should prove valuable for designing and evaluating new tests and devices.
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| 4. |
- Naeser, Ylva, et al.
(författare)
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TRIM study protocol - a prospective randomized multicenter Trial to assess the Role of Imaging during follow-up after radical surgery of stage IIB-C and III cutaneous malignant Melanoma
- 2020
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe incidence of cutaneous malignant melanoma (CMM) is increasing worldwide. In Sweden, over 4600 cases were diagnosed in 2018. The prognosis after radical surgery varies considerably with tumor stage. In recent years, new treatment options have become available for metastatic CMM. Early onset of treatment seems to improve outcome, which suggests that early detection of recurrent disease should be beneficial. Consequently, in several countries imaging is a part of the routine follow-up program after surgery of high risk CMM. However, imaging has drawbacks, including resources required (costs, personnel, equipment) and the radiation exposure. Furthermore, many patients experience anxiety in waiting for the imaging results and investigations of irrelevant findings is another factor that also could cause worry and lead to decreased quality of life. Hence, the impact of imaging in this setting is important to address and no randomized study has previously been conducted. The Swedish national guidelines stipulate follow-up for 3years by clinical examinations only.MethodsThe TRIM study is a prospective randomized multicenter trial evaluating the potential benefit of imaging and blood tests during follow-up after radical surgery for high-risk CMM, compared to clinical examinations only. Primary endpoint is overall survival (OS) at 5years. Secondary endpoints are survival from diagnosis of relapse and health-related quality of life (HRQoL). Eligible for inclusion are patients radically operated for CMM stage IIB-C or III with sufficient renal function for iv contrast-enhanced CT and who are expected to be fit for treatment in case of recurrence. The planned number of patients is >1300. Patients are randomized to clinical examinations for 3years +/- whole-body imaging with CT or FDG-PET/CT and laboratory tests including S100B protein and LDH. This academic study is supported by the Swedish Melanoma Study Group.DiscussionThis is the first randomized prospective trial on the potential benefit of imaging as a part of the follow-up scheme after radical surgery for high-risk CMM.ResultsThe first patient was recruited in June 2017 and as of April 2020, almost 500 patients had been included at 19 centers in Sweden.Trial registrationClinicalTrials.gov, NCT 03116412. Registered 17 April 2017, https://clinicaltrials.gov/ct2/show/study/NCT03116412
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| 5. |
- Sjöström, Johan, 1978-, et al.
(författare)
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En ny modell för gräsbrandsfara i Sverige
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Risken för antändning och snabb spridning av vegetationsbränder i skogsmark och i gräsmarkerskiljer sig markant. Gräsbränder sprider sig i dött fjolårsgräs, tidigt på våren, innan årets färskagräs hunnit växa till och dessa bränder kan spridas snabbt efter bara några timmars torrt väder.Risken klingar snabbt av med inväxten av färskt gräs för att i stort sett upphöra till sommaren.Skogsbränder har inte samma säsongsberoende av bränslet utan styrs mer av vädret. Därför skerde typiskt under sommaren och kräver oftast flera dagars torrt väder. Dessa skillnader gör attolika riskbedömningssystem måste användas för dessa två karakteristiska typer avvegetationsbränder.Här presenteras en ny modell för gräsbrandsfara som använder potentiell spridningshastighet iobetat, oklippt gräs som indikator på risk. Algoritmen tar väderhistoriken (snötäcke, relativluftfuktighet, vindhastighet, temperatur och solinstrålning) samt progressionen av årsgräsetsinväxt i beaktning. Modellen bygger på en modell för beräkning av fuktkvot i gräs utvecklad iNordamerika samt en modell för hur fuktkvoten och vindhastigheten inverkar påspridningshastigheten. Effekten av årsgräsets inväxt under svenska förhållanden beräknasgenom 25 års insats- och väder-data i tio regioner och en anpassning till tidigare utfördatestbränningar från snösmältning till gräsbrandssäsongens slut. Modellen kan uppdateras varjetimme, i linje med det uppdaterade brandrisksystemet i Sverige.Förslag till hur indelning i risknivåer ska utformas med avseende på riskindikatorn presenterasoch modellen sätts i bruk till våren 2021.
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| 6. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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A registry-based randomised trial comparing an SGLT2 inhibitor and metformin as standard treatment of early stage type 2 diabetes (SMARTEST): Rationale, design and protocol
- 2021
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Ingår i: Journal of Diabetes and Its Complications. - : Elsevier BV. - 1056-8727 .- 1873-460X. ; 35:10
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Tidskriftsartikel (refereegranskat)abstract
- Aim: SGLT2 inhibitors have been shown to reduce cardiovascular and renal complications in type 2 diabetes (T2D) patients at high cardiovascular risk. Metformin is currently widely used as initial monotherapy in T2D but lacks convincing data to show that it reduces risk of complications. We aim to compare the SGLT2 inhibitor dapagliflozin and metformin as first-line T2D medication with regard to development of complications in a registry-based randomised controlled trial. Methods: The SGLT2 inhibitor or metformin as standard treatment of early stage type 2 diabetes (SMARTEST) trial will enrol 4300 subjects at 30-40 study sites in Sweden who will be randomised 1:1 to either metformin or dapagliflozin. Participants must have T2D duration <4 years, no prior cardiovascular disease, and be either drug-naive or on monotherapy for T2D. Results: The primary endpoint is a composite of all-cause death, major adverse cardiovascular events and occurrence or progression of microvascular complications (retinopathy, nephropathy, diabetic foot lesions). Secondary endpoints include individual components of the primary endpoint, start of insulin therapy, risk factor biomarkers, patient-reported outcome measures, and cost-effectiveness analysis. Outcomes will primarily be assessed using nationwide healthcare registries. Conclusions: The SMARTEST trial will investigate whether dapagliflozin is superior to metformin in preventing complications in early stage T2D. (Clinicaltrials.gov identifier NCT03982381, EudraCT 2019-001046-17).
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| 7. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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Weight gain and blood pressure
- 2020
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Ingår i: Journal of Hypertension. - : Lippincott Williams & Wilkins. - 0263-6352 .- 1473-5598. ; 38:3, s. 387-394
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Although the causality of the obesity—hypertension association is established, the potential for prevention is not. We hypothesized that weight gain between early adulthood and mid-life is associated with higher mid-life blood pressure.METHODS: We investigated the hypothesis using a large contemporaneous population-based mid-life cohort of men and women aged 50-64 years. Recalled body weight at age 20 years was self-reported, and mid-life body weight and office blood pressures were measured in accordance with a detailed protocol.RESULTS: On average, men had gained 14.9 (95% CI 14.6-15.2) kg of weight, and women 14.6 (95% CI 14.4-14.9) kg, between age 20 years and the mid-life examination, corresponding to 0.40 (95% CI 0.39-0.41) kg/year for men and women. Both weight at age 20 years and weight at the mid-life examination were associated with mid-life blood pressures. On average, a 10 kg weight increase between age 20 years and mid-life was associated with 2.2 (95% CI 0.9-3.5) mmHg higher systolic and 1.7 (95% CI 0.9-2.5) mmHg higher diastolic mid-life blood pressure in men, and 3.2 (2.5-4.0) mmHg higher systolic and 2.4 (1.9-2.9) mmHg higher diastolic mid-life blood pressure in women. Mid-life weight was more closely associated than weight at age 20 years with mid-life blood pressure. For a given mid-life weight, blood pressure was higher in persons with higher weight gain from age 20 years.CONCLUSION: In sum, weight gain between early adulthood and mid-life was associated with higher mid-life blood pressure. The magnitude of the association indicates a potentially great public health impact of strategies to prevent weight gain throughout adulthood.
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| 8. |
- Ahlström, Christer, et al.
(författare)
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Effects of partially automated driving on the development of driver sleepiness
- 2021
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575 .- 1879-2057. ; 153
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to compare the development of sleepiness during manual driving versus level 2 partially automated driving, when driving on a motorway in Sweden. The hypothesis was that partially auto-mated driving will lead to higher levels of fatigue due to underload. Eighty-nine drivers were included in the study using a 2 ? 2 design with the conditions manual versus partially automated driving and daytime (full sleep) versus night-time (sleep deprived). The results showed that night-time driving led to markedly increased levels of sleepiness in terms of subjective sleepiness ratings, blink durations, PERCLOS, pupil diameter and heart rate. Partially automated driving led to slightly higher subjective sleepiness ratings, longer blink durations, decreased pupil diameter, slower heart rate, and higher EEG alpha and theta activity. However, elevated levels of sleepiness mainly arose from the night-time drives when the sleep pressure was high. During daytime, when the drivers were alert, partially automated driving had little or no detrimental effects on driver fatigue. Whether the negative effects of increased sleepiness during partially automated driving can be compensated by the positive effects of lateral and longitudinal driving support needs to be investigated in further studies.
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| 9. |
- Andersson, Peter, 1981-, et al.
(författare)
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Simulation of the response of a segmented High-Purity Germanium detector for gamma emission tomography of nuclear fuel
- 2020
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Ingår i: SN Applied Sciences. - : Springer. - 2523-3963 .- 2523-3971. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Irradiation testing of nuclear fuel is routinely performed in nuclear test reactors. For qualification and licensing of Accident Tolerant Fuels or Generation IV reactor fuels, an extensive increase in irradiation testing is foreseen in order to fill the gaps of existing validation data, both in normal operational conditions and in order to identify operational limits.Gamma Emission Tomography (GET) has been demonstrated as a viable technique for studies of the behavior of irradiated nuclear fuel, e.g. measurement of fission gas release and inspection of fuel behavior under Loss-Of-Coolant Accident conditions. In this work, the aim is to improve the technique of GET for irradiated nuclear fuel by developing a detector concept for an improved tomography system that allows for a higher spatial resolution and/or faster interrogation.We present the working principles of a novel concept for gamma emission tomography using a segmented High Purity Germanium (HPGe) detector. The performance of this concept was investigated using the Monte Carlo particle transport code MCNP. In particular, the data analysis of the proposed detector was evaluated, and the performance, in terms of full energy efficiency and localization failure rate, has been evaluated.We concluded that the segmented HPGe detector has an advantageous performance as compared to the traditional single-channel detector systems. Due to the scattering nature of gamma rays, a trade-off is presented between efficiency and cross-talk; however, the performance is nevertheless a substantial improvement over the currently used single-channel HPGe detector systems.
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| 10. |
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Att skriva med ljus. 13 essäer om litteratur och fotografi
- 2020
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Fotografins födelse på 1800-talet är en avgörande händelse i de visuella konsternas historia. Det var en medieteknologisk omvälvning som förändrade förutsättningarna också för litterärt skapande. Litteraturens och fotografins fortsatta samverkan kom att sätta djupa spår i fältet för konstnärlig produktion under 1900- och 2000-talen. Några av dess uttryck och effekter diskuteras i denna antologi som rör sig från fotografen Félix Nadars memoarer till filmskaparen Wim Wenders fototexter. Texter av: Mikael van Reis, Johan Gardfors, Kristoffer Noheden, Nils Olsson, Niclas Östlind, Louise Wolthers, Björn Billing, Thomas Hvid Kromann, Unni Langås, Sonia Lagerwall, Mats Jansson, Hans Kristian S. Rustad, Jørgen Bruhn,
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