| 1. |
- Hellström, Thomas, et al.
(författare)
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An intelligent rollator for mobility impaired persons, especially stroke patients
- 2016
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Ingår i: Journal of Medical Engineering & Technology. - : Taylor & Francis. - 0309-1902 .- 1464-522X. ; 40:5, s. 270-279
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Tidskriftsartikel (refereegranskat)abstract
- An intelligent rollator (IRO) was developed that aims at obstacle detection and guidance to avoid collisions and accidental falls. The IRO is a retrofit four-wheeled rollator with an embedded computer, two solenoid brakes, rotation sensors on the wheels and IR-distance sensors. The value reported by each distance sensor was compared in the computer to a nominal distance. Deviations indicated a present obstacle and caused activation of one of the brakes in order to influence the direction of motion to avoid the obstacle. The IRO was tested by seven healthy subjects with simulated restricted and blurred sight and five stroke subjects on a standardised indoor track with obstacles. All tested subjects walked faster with intelligence deactivated. Three out of five stroke patients experienced more detected obstacles with intelligence activated. This suggests enhanced safety during walking with IRO. Further studies are required to explore the full value of the IRO.
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| 2. |
- Hellström, Thomas, et al.
(författare)
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Tree diameter estimation using laser scanner
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Accurate vehicle localization in forest environments is still an unresolved problem. GPS has obvious limitations in dense forest, and has to be mixed with other techniques to provide satisfying solutions. One possible way is to localize the vehicle relative to trees detected around the vehicle. The first step to implement this method is is to find reliable methods to detect trees, and also to match them to maps. The reliability of this matching operation is improved by accurate estimations of tree diameter. In this paper we evaluate a number of existing algorithms for detection of trees and estimation of tree diameter. Three new algorithms are also suggested. All algorithms were evaluated in field experiments at three different locations with varying tree trunk visibility. The results show that one of the existing algorithms is clearly less reliable than the other two. Noticeable is that the existing algorithms often overestimate tree trunk diameter. The new algorithms mostly underestimate, but are most accurate in some situations.
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| 3. |
- Hohnloser, Peter, 1983-
(författare)
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Tree identificationand trunk diameter estimation with a 2D laser scanner
- 2013
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Ingår i: Proceedings of Umeå's 16th student conference in computing science. - Umeå : Umeå universitet. ; , s. 27-38
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents an algorithm for identifying trees in a 2Dlaser scan and six different tree trunk diameter estimation methods. Thetree identification algorithm turned out to be very sensitive and hence notalways as reliable as one could wish. Of the tree trunk estimation methodsthree were developed during this work. All methods were tested andcompared in an experimental way to find out which is most appropriateto use in forestry. The experiment was conducted on three positionswhere the tree trunks visibility differed. The result shows that one ofthe existing methods is not as reliable as the other ones and the othertwo existing ones give a similar result. Noticeable is that the existingmethods overestimates the tree trunk diameter and the newly developedmethods mostly underestimates it, but as the experiment shows givesthe most accurate result in some positions.
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| 4. |
- Kowey, Peter R, et al.
(författare)
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Efficacy and safety of celivarone, with amiodarone as calibrator, in patients with an implantable cardioverter-defibrillator for prevention of implantable cardioverter-defibrillator interventions or death : the ALPHEE study
- 2011
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 124:24, s. 2649-2660
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Celivarone is a new antiarrhythmic agent developed for the treatment of ventricular arrhythmias. This study investigated the efficacy and safety of celivarone in preventing implantable cardioverter-defibrillator (ICD) interventions or death. METHODS AND RESULTS: Celivarone (50, 100, or 300 mg/d) was assessed compared with placebo in this randomized, double-blind, placebo-controlled, parallel-group study. Amiodarone (200 mg/d after loading dose of 600 mg/d for 10 days) was used as a calibrator. A total of 486 patients with a left ventricular ejection fraction ≤40% and at least 1 ICD intervention for ventricular tachycardia or ventricular fibrillation in the previous month or ICD implantation in the previous month for documented ventricular tachycardia/ventricular fibrillation were randomized. Median treatment duration was 9 months. The primary efficacy end point was occurrence of ventricular tachycardia/ventricular fibrillation-triggered ICD interventions (shocks or antitachycardia pacing) or sudden death. The proportion of patients experiencing an appropriate ICD intervention or sudden death was 61.5% in the placebo group; 67.0%, 58.8%, and 54.9% in the celivarone 50-, 100-, and 300-mg groups, respectively; and 45.3% in the amiodarone group. Hazard ratios versus placebo for the primary end point ranged from 0.860 for celivarone 300 mg to 1.199 for celivarone 50 mg. None of the comparisons versus placebo were statistically significant. Celivarone had an acceptable safety profile. CONCLUSIONS: Celivarone was not effective for the prevention of ICD interventions or sudden death. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT00993382.
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| 5. |
- Lindroos, Ola, et al.
(författare)
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Estimating the position of the harvester head : a key step towards the precision forestry of the future?
- 2015
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Ingår i: Croatian Journal of Forest Engineering. - Zagreb : University of Zagreb. - 1845-5719 .- 1848-9672. ; 36:2, s. 147-164
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Tidskriftsartikel (refereegranskat)abstract
- Modern harvesters are technologically sophisticated, with many useful features such as the ability to automatically measure stem diameters and lengths. This information is processed in real time to support value optimization when cutting stems into logs. It can also be transferred from the harvesters to centralized systems and used for wood supply management. Such information management systems have been available since the 1990s in Sweden and Finland, and are constantly being upgraded. However, data on the position of the harvester head relative to the machine are generally not recorded during harvesting. The routine acquisition and analysis of such data could offer several opportunities to improve forestry operations and related processes in the future. Here, we analyze the possible benefits of having this information, as well as the steps required to collect and process it. The benefits and drawbacks of different sensing technologies are discussed in terms of potential applications, accuracy and cost. We also present the results of preliminary testing using two of the proposed methods. Our analysis indicates that an improved scope for mapping and controlling machine movement is the main benefit that is directly related to the conduct of forestry operations. In addition, there are important indirect benefits relating to ecological mapping. Our analysis suggests that both of these benefits can be realized by measuring the angles of crane joints or the locations of crane segments and using the resulting information to compute the head's position. In keeping with our findings, two companies have recently introduced sensor equipped crane solutions.
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| 6. |
- Lopes, Renato D., et al.
(författare)
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Digoxin and Mortality in Patients With Atrial Fibrillation
- 2018
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Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 71:10, s. 1063-1074
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Digoxin is widely used in patients with atrial fibrillation (AF). OBJECTIVES The goal of this paper was to explore whether digoxin use was independently associated with increased mortality in patients with AF and if the association was modified by heart failure and/or serum digoxin concentration.METHODS: The association between digoxin use and mortality was assessed in 17,897 patients by using a propensity score-adjusted analysis and in new digoxin users during the trial versus propensity score-matched control participants. The authors investigated the independent association between serum digoxin concentration and mortality after multivariable adjustment.RESULTS: At baseline, 5,824 (32.5%) patients were receiving digoxin. Baseline digoxin use was not associated with an increased risk of death (adjusted hazard ratio [HR]: 1.09; 95% confidence interval [CI]: 0.96 to 1.23; p = 0.19). However, patients with a serum digoxin concentration $ 1.2 ng/ml had a 56% increased hazard of mortality (adjusted HR: 1.56; 95% CI: 1.20 to 2.04) compared with those not on digoxin. When analyzed as a continuous variable, serum digoxin concentration was associated with a 19% higher adjusted hazard of death for each 0.5-ng/ml increase (p = 0.0010); these results were similar for patients with and without heart failure. Compared with propensity score-matched control participants, the risk of death (adjusted HR: 1.78; 95% CI: 1.37 to 2.31) and sudden death (adjusted HR: 2.14; 95% CI: 1.11 to 4.12) was significantly higher in new digoxin users.CONCLUSIONS: In patients with AF taking digoxin, the risk of death was independently related to serum digoxin concentration and was highest in patients with concentrations $ 1.2 ng/ml. Initiating digoxin was independently associated with higher mortality in patients with AF, regardless of heart failure.
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| 7. |
- Ringdahl, Ola, 1971-, et al.
(författare)
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Enhanced Algorithms for Estimating Tree Trunk Diameter Using 2D Laser Scanner
- 2013
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Ingår i: Remote Sensing. - Basel : MDPI. - 2072-4292. ; 5:10, s. 4839-4856
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Tidskriftsartikel (refereegranskat)abstract
- Accurate vehicle localization in forest environments is still an unresolved problem. Global navigation satellite systems (GNSS) have well known limitations in dense forest, and have to be combined with for instance laser based SLAM algorithms to provide satisfying accuracy. Such algorithms typically require accurate detection of trees, and estimation of tree center locations in laser data. Both these operations depend on accurate estimations of tree trunk diameter. Diameter estimations are important also for several other forestry automation and remote sensing applications. This paper evaluates several existing algorithms for diameter estimation using 2D laser scanner data. Enhanced algorithms, compensating for beam width and using multiple scans, were also developed and evaluated. The best existing algorithms overestimated tree trunk diameter by ca. 40%. Our enhanced algorithms, compensating for laser beam width, reduced this error to less than 12%.
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| 8. |
- Vamos, Mate, et al.
(författare)
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Efficacy and safety of dronedarone in patients with a prior ablation for atrial fibrillation/flutter : Insights from the ATHENA study
- 2020
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289 .- 1932-8737. ; 43:3, s. 291-297
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Tidskriftsartikel (refereegranskat)abstract
- Background: The role of antiarrhythmic drugs for atrial fibrillation/atrial flutter (AF/AFL) after catheter ablation is not well established. Hypothesis: We hypothesized that changing the myocardial substrate by ablation may alter the responsiveness to dronedarone. Methods: We assessed the efficacy and safety of dronedarone in the treatment of paroxysmal/persistent atrial fibrillation/atrial flutter (AF/AFL) post-ablation, based on a post hoc analysis of the ATHENA study. A total of 196 patients (dronedarone 90, placebo 106) had an ablation for AF/AFL before study entry. In these patients, the effect of treatment on the first hospitalization because of cardiovascular (CV) events/all-cause death was assessed, as was AF/AFL recurrence in individuals with sinus rhythm at baseline. The safety of dronedarone vs placebo was also determined. Results: In patients with prior ablation, dronedarone reduced the risk of AF/AFL recurrence (hazard ratio [HR]: 0.65 [95% confidence interval [CI]: 0.42, 1.00]; P <.05) as well as the median time to first AF/AFL recurrence (561 vs 180 days) compared with placebo. The HR for first CV hospitalization/all-cause death with dronedarone vs placebo was 0.98 (95% CI: 0.62, 1.53; P =.91). Rates of treatment-emergent adverse events were 83.1% vs 75.5% and rates of serious TEAEs were 27.0% vs 18.9% in the dronedarone and placebo groups, respectively. One death occurred with dronedarone (not treatment-emergent) and five occurred with placebo. Conclusion: In patients with prior ablation for AF/AFL, dronedarone reduced the risk of AF/AFL recurrence compared with placebo, but not the risk of first CV hospitalization/all-cause death. Safety outcomes were consistent with those of the overall ATHENA study.
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