| 1. |
- Bratt, Mattias, et al.
(författare)
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Design of a Control Strategy for Teleoperation of a Platform with Significant Dynamics
- 2006
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Ingår i: 2006 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vols 1-12. - NEW YORK, NY : IEEE. - 9781424402588 ; , s. 1700-1705
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Konferensbidrag (refereegranskat)abstract
- A teleoperation system for controlling a robot with fast dynamics over the Internet has been constructed. It employs a predictive control structure with an accurate dynamic model of the robot to overcome problems caused by varying delays. The operator interface uses a stereo virtual reality display of the robot cell, and a haptic device for force feed-back including virtual obstacle avoidance forces.
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| 2. |
- Bratt, Mattias, et al.
(författare)
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Minimum jerk based prediction of user actions for a ball catching task
- 2007
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Ingår i: IEEE International Conference on Intelligent Robots and Systems. - : IEEE conference proceedings. - 9781424409112 ; , s. 2716-2722
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Konferensbidrag (refereegranskat)abstract
- The present paper examines minimum jerk models for human kinematics as a tool to predict user input in teleoperation with significant dynamics. Predictions of user input can be a powerful tool to bridge time-delays and to trigger autonomous sub-sequences. In this paper an example implementation is presented, along with the results of a pilot experiment in which a virtual reality simulation of a teleoperated ball-catching scenario is used to test the predictive power of the model. The results show that delays up to 100 ms can potentially be bridged with this approach.
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| 3. |
- Bratt, Mattias, 1973-
(författare)
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Teleoperation with significant dynamics
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject of this thesis is teleoperation, and especially teleoperation with demanding time constraints due to significant dynamics inherent in the task. A comprehensive background is given, describing many aspects of teleoperation, from history and applications to operator interface hardware and relevant control theory concepts. Then follows a presentation of the research done by the author. Two prototypical highly dynamic teleoperation tasks have been attempted: high speed driving, and ball catching. Systems have been developed for both, employing operator interfaces tailored to facilitate perception of the remote scene and including assistive features to promote successful task completion within the required time frame. Prediction of the state at the remote site as well as of operator action has been applied to address the problem of delays arising when using the Internet as the communication channel.
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| 4. |
- Casper, C, et al.
(författare)
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Coreceptor usage of primary HIV type 1 isolates obtained from different lymph node subsets
- 2005
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Ingår i: AIDS Research and Human Retroviruses. - : Mary Ann Liebert Inc. - 1931-8405 .- 0889-2229. ; 21:12, s. 1003-1010
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Tidskriftsartikel (refereegranskat)abstract
- Biological characteristics of virus quantitatively rescued from different cell types present in lymph nodes of HIV-1-infected individuals in various stages of their disease were determined, not including patients with AIDS defining illness. Viruses were obtained by cocultivation with donor monocyte-derived macrophages and T-lymphocytes and their biological phenotype compared to viruses obtained from the peripheral blood mononuclear cells of the same patient. The biological phenotype was determined on established cell lines (U937-2, CEM, and MT-2) and on the U87.CD4 coreceptor indicator cell lines and variable region 3 (V3) of the envelope was subjected to direct sequencing. All isolates obtained from lymph node subsets used CCR5 as coreceptor. Furthermore, these viruses were also sensitive to inhibition by beta-chemokines as analyzed for viruses of one patient. All 12 V3 regions showed a unique sequence indicating compartmentalization within each patient. The biological phenotype of CCR5-dependent (R5) HIV-1 isolates obtained from PBMC resembles the phenotype of viruses isolated from different lymph node cell subsets.
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| 5. |
- Hedskog, Charlotte, et al.
(författare)
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Dynamics of HIV-1 Quasispecies during Antiviral Treatment Dissected Using Ultra-Deep Pyrosequencing
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:7, s. e11345-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ultra-deep pyrosequencing (UDPS) allows identification of rare HIV-1 variants and minority drug resistance mutations, which are not detectable by standard sequencing. Principal Findings: Here, UDPS was used to analyze the dynamics of HIV-1 genetic variation in reverse transcriptase (RT) (amino acids 180-220) in six individuals consecutively sampled before, during and after failing 3TC and AZT containing antiretroviral treatment. Optimized UDPS protocols and bioinformatic software were developed to generate, clean and analyze the data. The data cleaning strategy reduced the error rate of UDPS to an average of 0.05%, which is lower than previously reported. Consequently, the cut-off for detection of resistance mutations was very low. A median of 16,016 (range 2,406-35,401) sequence reads were obtained per sample, which allowed detection and quantification of minority resistance mutations at amino acid position 181, 184, 188, 190, 210, 215 and 219 in RT. In four of five pre-treatment samples low levels (0.07-0.09%) of the M184I mutation were observed. Other resistance mutations, except T215A and T215I were below the detection limit. During treatment failure, M184V replaced M184I and dominated the population in combination with T215Y, while wild-type variants were rarely detected. Resistant virus disappeared rapidly after treatment interruption and was undetectable as early as after 3 months. In most patients, drug resistant variants were replaced by wild-type variants identical to those present before treatment, suggesting rebound from latent reservoirs. Conclusions: With this highly sensitive UDPS protocol preexisting drug resistance was infrequently observed; only M184I, T215A and T215I were detected at very low levels. Similarly, drug resistant variants in plasma quickly decreased to undetectable levels after treatment interruption. The study gives important insights into the dynamics of the HIV-1 quasispecies and is of relevance for future research and clinical use of the UDPS technology.
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| 6. |
- Holmström, Benny, et al.
(författare)
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PSA-testet håller inte för screening: bra – men inte tillräckligt bra : [The PSA test does not hold for screening: good – but not good enough]
- 2009
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Ingår i: Läkartidningen. - : Sveriges läkarförbund. - 0023-7205 .- 1652-7518. ; 107:7, s. 436, 438-439
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Tidskriftsartikel (refereegranskat)abstract
- Prostatacancer är den vanligaste cancersjukdomen och den vanligaste cancerrelaterade dödsorsaken bland män i Sverige. Screening för prostataspecifikt antigen (PSA) minskade dödligheten i prostatacancer med 20 procent i en stor randomiserad studie. En utvärdering av PSA-test med sannolikhetskvot (likelihood ratio) visade att det inte uppfyller kriterierna för ett screeningtest. Män ska ha information om PSA-testets för- och nackdelar innan testet utförs. En broschyr med sådan information finns tillgänglig på .
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| 7. |
- Karlsson, Annika, et al.
(författare)
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Low Prevalence of Transmitted Drug Resistance in Patients Newly Diagnosed with HIV-1 Infection in Sweden 2003-2010.
- 2012
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Transmitted drug resistance (TDR) is a clinical and epidemiological problem because it may contribute to failure of antiretroviral treatment. The prevalence of TDR varies geographically, and its prevalence in Sweden during the last decade has not been reported. Plasma samples from 1,463 patients newly diagnosed with HIV-1 infection between 2003 and 2010, representing 44% of all patients diagnosed in Sweden during this period, were analyzed using the WHO 2009 list of mutations for surveillance of TDR. Maximum likelihood phylogenetic analyses were used to determine genetic subtype and to investigate the relatedness of the sequences. Eighty-two patients showed evidence of TDR, representing a prevalence of 5.6% (95% CI: 4.5%-6.9%) without any significant time trends or differences between patients infected in Sweden or abroad. Multivariable logistic regression showed that TDR was positively associated with men who have sex with men (MSM) and subtype B infection and negatively associated with CD4 cell counts. Among patients with TDR, 54 (68%) had single resistance mutations, whereas five patients had multi-drug resistant HIV-1. Phylogenetic analyses identified nine significantly supported clusters involving 29 of the patients with TDR, including 23 of 42 (55%) of the patients with TDR acquired in Sweden. One cluster contained 18 viruses with a M41L resistance mutation, which had spread among MSM in Stockholm over a period of at least 16 years (1994-2010). Another cluster, which contained the five multidrug resistant viruses, also involved MSM from Stockholm. The prevalence of TDR in Sweden 2003-2010 was lower than in many other European countries. TDR was concentrated among MSM, where clustering of TDR strains was observed, which highlights the need for continued and improved measures for targeted interventions.
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| 8. |
- Smith, Christian, et al.
(författare)
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Teleoperation for a ball-catching task with significant dynamics
- 2008
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Ingår i: Neural Networks. - : Elsevier. - 0893-6080 .- 1879-2782. ; 21:4, s. 604-620
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present ongoing work on how to incorporate human motion models into the design of a high performance teleoperation platform. A short description of human motion models used for ball-catching is followed by a more detailed study of a teleoperation platform on which to conduct experiments. Also, a pilot study using minimum jerk theory to explain user input behavior in teleoperated catching is presented.
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