| 1. |
- Aghanavesi, Somayeh, 1981-, et al.
(författare)
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A multiple motion sensors index for motor state quantification in Parkinson's disease
- 2020
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Ingår i: Computer Methods and Programs in Biomedicine. - : Elsevier BV. - 0169-2607 .- 1872-7565. ; 189
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To construct a Treatment Response Index from Multiple Sensors (TRIMS) for quantification of motor state in patients with Parkinson's disease (PD) during a single levodopa dose. Another aim was to compare TRIMS to sensor indexes derived from individual motor tasks. Method: Nineteen PD patients performed three motor tests including leg agility, pronation-supination movement of hands, and walking in a clinic while wearing inertial measurement unit sensors on their wrists and ankles. They performed the tests repeatedly before and after taking 150% of their individual oral levodopa-carbidopa equivalent morning dose.Three neurologists blinded to treatment status, viewed patients’ videos and rated their motor symptoms, dyskinesia, overall motor state based on selected items of Unified PD Rating Scale (UPDRS) part III, Dyskinesia scale, and Treatment Response Scale (TRS). To build TRIMS, out of initially 178 extracted features from upper- and lower-limbs data, 39 features were selected by stepwise regression method and were used as input to support vector machines to be mapped to mean reference TRS scores using 10-fold cross-validation method. Test-retest reliability, responsiveness to medication, and correlation to TRS as well as other UPDRS items were evaluated for TRIMS. Results: The correlation of TRIMS with TRS was 0.93. TRIMS had good test-retest reliability (ICC = 0.83). Responsiveness of the TRIMS to medication was good compared to TRS indicating its power in capturing the treatment effects. TRIMS was highly correlated to dyskinesia (R = 0.85), bradykinesia (R = 0.84) and gait (R = 0.79) UPDRS items. Correlation of sensor index from the upper-limb to TRS was 0.89. Conclusion: Using the fusion of upper- and lower-limbs sensor data to construct TRIMS provided accurate PD motor states estimation and responsive to treatment. In addition, quantification of upper-limb sensor data during walking test provided strong results. © 2019
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| 2. |
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| 3. |
- Appelgren, Patrik, et al.
(författare)
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Modeling of a small helical magnetic flux compression generator
- 2008
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Ingår i: IEEE Transactions on Plasma Science. - 0093-3813 .- 1939-9375. ; 36:5, s. 2662-2672
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Tidskriftsartikel (refereegranskat)abstract
- In order to gain experience in explosive pulsed power and to provide experimental data as the basis for computer modeling, a small high-explosive-driven helical magnetic flux-compression generator (FCG) was designed at the Swedish Defence Research Agency. The generator, of which three have been built, has an overall length of 300 mm and a diameter of 70 mm. It could serve as the energy source in a pulse-forming network to generate high-power pulses for various loads. This paper presents a simulation model of this helical FCG. The model, which was implemented in Matlab-Simulink, uses analytical expressions for the generator inductance. The model of resistive losses takes into account the heating of the conductors and the diffusion of the magnetic field into the conductors. The simulation results are compared with experimental data from two experiments with identical generators but with different seed currents, influencing the resistive losses. The model is used to analyze the performance of the generator.
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| 4. |
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| 5. |
- Appelgren, Patrik, et al.
(författare)
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Small Helical Magnetic Flux-Compression Generators : Experiments and Analysis
- 2008
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Ingår i: IEEE Transactions on Plasma Science. - 0093-3813 .- 1939-9375. ; 36:5, s. 2673-2683
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Tidskriftsartikel (refereegranskat)abstract
- In order to gain experience in explosive pulsed power and to provide experimental data for modeling, a small high-explosive-driven helical magnetic flux-compression generator (FCG) was designed at the Swedish Defence Research Agency (FOI). The generator, of which three have been built, has an overall length of 300 mm and a diameter of 70 mm. It could serve as the energy source in a pulse-forming network to generate high power pulses for various loads. This paper presents the design of, and tests with, this helical FCG. The generator had an initial inductance of 23 mu H and was operated into a load of 0.2 mu H. The generator is charged with 0.27 kg of high explosives (PBXN-5). Various types of diagnostics were used to monitor the operation of the generator, including current probes, optical fibers, and piezo gauges. With seed currents of 5.7 and 11.2 kA, final currents of 269 and 436 kA were obtained, corresponding to current amplification factors of 47 and 39. The peak of the current was reached about 30 mu s after the time of crowbar. The two generators showed only small losses in terms of 2 pi-clocking. Using signals from optical fibers, the deflection angle of the armature could be determined to be 10 degrees in good agreement with hydrodynamic simulations of the detonation process and the detonation velocity to be 8.7 km/s in agreement with tabulated value.
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| 6. |
- Aquilonius, Sten-Magnus, et al.
(författare)
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Development of new levodopa treatment strategies in Parkinson’s disease – from bedside to bench to bedside
- 2017
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Ingår i: Upsala Journal of Medical Sciences. - 0300-9734 .- 2000-1967. ; 122:2, s. 71-77
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Forskningsöversikt (refereegranskat)abstract
- This review will illustrate the process of moving from an idea through preclinical research and Galenic developments into clinical investigations and finally to approval by regulatory agencies within the European Union. The two new treatment strategies described, levodopa/carbidopa intestinal gel and levodopa/carbidopa microtablets, for advanced Parkinson's disease, have been developed in collaborative research within departments at Uppsala University. With this historical approach, reference priority is given to reports considered to be of special importance for this more than two decades long process from bedside to bench to bedside'.
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| 7. |
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| 8. |
- Bredenberg, Susanne, et al.
(författare)
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An automatic dose dispenser for microtablets : A new concept for individual dosage of drugs in tablet form
- 2003
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Ingår i: International Journal of Pharmaceutics. - 0378-5173. ; 261:1-2, s. 137-146
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Tidskriftsartikel (refereegranskat)abstract
- A new concept for individualising the dosage of drugs in solid form is presented. The principle is based on the use of standardised units (microtablets), each containing a subtherapeutic amount of the active ingredient. The required dose is fine-tuned by counting out a specific number of these units. The microtablets are counted electronically from the attached cassette by the automatic dispensing device. The individual dose is set and the dispenser counts and delivers the correct number of microtablets. The usefulness of the automatic dispenser concept and acceptability of the apparatus were evaluated in patients with Parkinson’s disease (PD). After initial instruction on use of the dispenser, 20 patients operated it themselves. All patients were generally satisfied with their management of the automatic dispenser and most would be happy to use the device again. Further technical development is required before use in clinical practice, but the current prototype may be acceptable for some patients. It is concluded that the final version of the automatic dose dispenser concept will offer potential for improvement of drug administration for patients with PD or other diseases requiring individual dosage.
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| 9. |
- Elfsberg, Mattias, et al.
(författare)
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Experimental Studies of Anode and Cathode Materials in a Repetitive Driven Axial Vircator
- 2008
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Ingår i: IEEE Transactions on Plasma Science. - 0093-3813 .- 1939-9375. ; 36, s. 688-693
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Tidskriftsartikel (refereegranskat)abstract
- Repetitive use of a high-power microwave (HPM) radiation source implies strong erosion on cathode and anode materials. Electrode material endurance has been studied in a series of experiments with an axial vircator powered by a compact Marx generator. The Marx generator operated in a 10 Hz repetitive mode with a burst of ten pulses. Velvet and graphite was used as electron-emitting materials, and they showed markedly different pulse characteristics. Three different anode materials were used; stainless steel mesh, stainless steel wires and molybdenum wires, which all had different influence on the pulse characteristics.
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| 10. |
- Elfsberg, Mattias, et al.
(författare)
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Experimental studies on a coaxial vircator, designed for operation in TE11 mode
- 2011
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Ingår i: Proc. of Pulse Power Conference (PPC 2011). ; , s. 811-814
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Konferensbidrag (refereegranskat)abstract
- Experiments on a coaxial vircator have been performed. A vircator is a narrow band high power microwave source without any external generated magnetic field [1]. A coaxial vircator is an advantageous design of a microwave radiation source for a compact HPM-system. With a limited size and outer diameter it is possible to use a larger emitting area compared to an axial design. A conventional coaxial vircator will generate the radiation in TM01 mode, due to its geometrical properties. For a compact HPM-system, radiation in TE11 mode is preferred when the radiated energy needs to be focused on a specific target. For operation in TE11 mode a sectioned emitter can be used rather than a circumcircular. The efficiency of the vircator can be greatly improved by optimizing the geometry of the vircator housing. The impedance of the pulsed power supply driving the vircator and the impedance of the vircator, depending on the A-K gap and amount of emitting material, is also important for maximizing the vircator efficiency. For the experiments reported on, the vircator was driven by a 500 kV/500 J compact Marx generator that can be operated repetitively at 10 Hz. For these experiments, the Marx generator was operating in single shot mode. During the experiments presented here, a couple of geometrical features were varied as well as the applied voltage. Their influence on the radiated field strength, dominating frequency and bandwidth are reported on and discussed.
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