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Rydell, Joakim
Publications (10 of 29) Show all publications
Eklund, A., Ohlsson, H., Andersson, M., Rydell, J., Ynnerman, A. & Knutsson, H. (2009). Balancing an Inverted Pendulum by Thinking A Real-Time fMRI Approach. Paper presented at SSBA Symposium on Image Analysis, 18-20 March, Halmstad, Sweden, 2009.
Open this publication in new window or tab >>Balancing an Inverted Pendulum by Thinking A Real-Time fMRI Approach
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2009 (English)Conference paper, Published paper (Other academic)
Abstract [en]

We present a method for controlling a dynamical system using real-time fMRI. The objective for the subject in the MR scanner is to balance an inverse pendulum by activating the left or right hand or resting. The brain activity is classified each second by a neural network and the classification is sent to a pendulum simulator to change the force applied to the pendulum. The state of the inverse pendulum is shown to the subject in a pair of VR goggles. The subject was able to balance the inverse pendulum both with real activity and imagined activity. The developments here have a potential to aid people with communication disabilities e.g., locked in people. It might also be a tool for stroke patients to be ableto train the damaged brain area and get real-time feedback of when they do it right.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-65737 (URN)
Conference
SSBA Symposium on Image Analysis, 18-20 March, Halmstad, Sweden, 2009
Available from: 2011-02-18 Created: 2011-02-18 Last updated: 2015-09-22Bibliographically approved
Dahlqvist Leinhard, O., Johansson, A., Rydell, J., Kihlberg, J., Smedby, Ö., Nyström, F. H., . . . Borga, M. (2009). Quantification of abdominal fat accumulation during hyperalimentation using MRI. In: Proceedings of the ISMRM Annual Meeting (ISMRM'09), 2009: . Paper presented at ISMRM Annual Meeting (ISMRM'09), Honolulu, Hawaii, USA 18-24 April, 2009 (pp. 206). Berkeley, CA, USA: International Society for Magnetic Resonance in Medicine
Open this publication in new window or tab >>Quantification of abdominal fat accumulation during hyperalimentation using MRI
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2009 (English)In: Proceedings of the ISMRM Annual Meeting (ISMRM'09), 2009, Berkeley, CA, USA: International Society for Magnetic Resonance in Medicine , 2009, p. 206-Conference paper, Published paper (Other academic)
Abstract [en]

There is an increasing demand for imaging methods that can be used for automatic, accurate and quantitative determination of the amounts of abdominal fat. Such methods are important as they will allow the evaluation of some of the risk factors underlying the ’metabolic syndrome’. The metabolic syndrome is becoming common in large parts of the world, and it appears that a dominant risk factor for developing this syndrome is abdominal obesity. Subjects that are afflicted with the metabolic syndrome are exposed to a high risk for developing a large range of diseases such as type 2 diabetes, cardiac failure, and stroke. The aim of this work

Place, publisher, year, edition, pages
Berkeley, CA, USA: International Society for Magnetic Resonance in Medicine, 2009
National Category
Biomedical Laboratory Science/Technology
Identifiers
urn:nbn:se:liu:diva-58084 (URN)
Conference
ISMRM Annual Meeting (ISMRM'09), Honolulu, Hawaii, USA 18-24 April, 2009
Available from: 2010-08-23 Created: 2010-07-28 Last updated: 2019-06-14Bibliographically approved
Eklund, A., Ohlsson, H., Andersson, M., Rydell, J., Ynnerman, A. & Knutsson, H. (2009). Using Real-Time fMRI to Control a Dynamical System. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Using Real-Time fMRI to Control a Dynamical System
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2009 (English)Report (Other academic)
Abstract [en]

We present e method for controlling a dynamical system using real-time fMRI. The objective for the subject in the MR scanner is to balance an inverse pendulum by activating the left or right hand or resting. The brain activity is clasified each second by a neural network and the classification is sent to a pendulum simulator to change the state of the pendulum. The state of the inverse pendulum is shown to the subject in a pair of VR goggles. The subject was able to balance the inverse pendulum during a 7 minute test run.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2009. p. 2
Series
LiTH-ISY-R, ISSN 1400-3902 ; 2879
Keywords
fMRI
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-56193 (URN)Using Real-Time fMRI to Control a Dynamical System (ISRN)
Available from: 2010-04-30 Created: 2010-04-30 Last updated: 2015-09-22Bibliographically approved
Eklund, A., Ohlsson, H., Andersson, M., Rydell, J., Ynnerman, A. & Knutsson, H. (2009). Using Real-Time fMRI to Control a Dynamical System. In: ISMRM 17th Scientific Meeting & Exhibition: . Paper presented at ISMRM 17th Scientific Meeting & Exhibition, Honolulu, Hawaii, USA, 18-24 April 2009.
Open this publication in new window or tab >>Using Real-Time fMRI to Control a Dynamical System
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2009 (English)In: ISMRM 17th Scientific Meeting & Exhibition, 2009Conference paper, Published paper (Refereed)
Abstract [en]

We present e method for controlling a dynamical system using real-time fMRI. The objective for the subject in the MR scanner is to balance an inverse pendulum by activating the left or right hand or resting. The brain activity is clasified each second by a neural network and the classification is sent to a pendulum simulator to change the state of the pendulum. The state of the inverse pendulum is shown to the subject in a pair of VR goggles. The subject was able to balance the inverse pendulum during a 7 minute test run.

Keywords
fMRI
National Category
Control Engineering Medical Imaging
Identifiers
urn:nbn:se:liu:diva-58082 (URN)
Conference
ISMRM 17th Scientific Meeting & Exhibition, Honolulu, Hawaii, USA, 18-24 April 2009
Projects
CMIV, CADICS, MOVIII
Available from: 2010-08-23 Created: 2010-07-28 Last updated: 2025-02-09Bibliographically approved
Eklund, A., Ohlsson, H., Andersson, M., Rydell, J., Ynnerman, A. & Knutsson, H. (2009). Using Real-Time fMRI to Control a Dynamical System by Brain Activity Classification (1ed.). In: Guang-Zhong Yang, David Hawkes, Daniel Rueckert, Alison Noble and Chris Taylor (Ed.), Gerhard Goos, Juris Hartmanis and Jan van Leeuwen (Ed.), Medical Image Computing and Computer-Assisted Intervention – MICCAI 2009: 12th International Conference, London, UK, September 20-24, 2009, Proceedings, Part I. Paper presented at MICCAI 2009, 12th International Conference, London, UK, September 20-24, 2009 (pp. 1000-1008). Springer Berlin/Heidelberg
Open this publication in new window or tab >>Using Real-Time fMRI to Control a Dynamical System by Brain Activity Classification
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2009 (English)In: Medical Image Computing and Computer-Assisted Intervention – MICCAI 2009: 12th International Conference, London, UK, September 20-24, 2009, Proceedings, Part I / [ed] Gerhard Goos, Juris Hartmanis and Jan van Leeuwen, Springer Berlin/Heidelberg, 2009, 1, p. 1000-1008Conference paper, Published paper (Refereed)
Abstract [en]

We present a method for controlling a dynamical system using real-time fMRI. The objective for the subject in the MR scanner is to balance an inverted pendulum by activating the left or right hand or resting. The brain activity is classified each second by a neural network and the classification is sent to a pendulum simulator to change the force applied to the pendulum. The state of the inverted pendulum is shown to the subject in a pair of VR goggles. The subject was able to balance the inverted pendulum during several minutes, both with real activity and imagined activity. In each classification 9000 brain voxels were used and the response time for the system to detect a change of activity was on average 2-4 seconds. The developments here have a potential to aid people with communication disabilities, such as locked in people. Another future potential application can be to serve as a tool for stroke and Parkinson patients to be able to train the damaged brain area and get real-time feedback for more efficient training.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2009 Edition: 1
Series
Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349 ; 5761
Keywords
fMRI
National Category
Medical Imaging
Identifiers
urn:nbn:se:liu:diva-54034 (URN)10.1007/978-3-642-04268-3_123 (DOI)000273617300123 ()978-3-642-04267-6 (ISBN)978-3-642-04268-3 (ISBN)
Conference
MICCAI 2009, 12th International Conference, London, UK, September 20-24, 2009
Projects
CADICS
Note

The original publication is available at www.springerlink.com: Anders Eklund, Henrik Ohlsson, Mats Andersson, Joakim Rydell, Anders Ynnerman and Hans Knutsson, Using Real-Time fMRI to Control a Dynamical System by Brain Activity Classification, 2009, Medical Image Computing and Computer-Assisted Intervention – MICCAI 2009, Lecture Notes in Computer Science, (5761/2009), 1000-1008. http://dx.doi.org/10.1007/978-3-642-04268-3_123 Copyright: Springer Science Business Media http://www.springerlink.com/

Available from: 2010-02-19 Created: 2010-02-19 Last updated: 2025-02-09Bibliographically approved
Rydell, J., Knutsson, H. & Borga, M. (2008). Bilateral Filtering of fMRI Data. IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING, 2(6), 891-896
Open this publication in new window or tab >>Bilateral Filtering of fMRI Data
2008 (English)In: IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING, ISSN 1932-4553, Vol. 2, no 6, p. 891-896Article in journal (Refereed) Published
Abstract [en]

We present a class of adaptive filtering techniques of functional magnetic resonance imaging (fMRI) data related to bilateral filtering. This class of methods average activities in consistent regions rather than regions that maximize correlation with a BOLD model. Similarity measures based on signal similarity and anatomical similarity are discussed and compared experimentally to standard linear low pass filtering. It is demonstrated that adaptive filtering provides improved detection of activated regions.

Keywords
Biomedical image processing, magnetic resonance imaging, nonlinear filters
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-18152 (URN)10.1109/JSTSP.2008.2007826 (DOI)000265495700008 ()
Available from: 2009-05-09 Created: 2009-05-08 Last updated: 2015-10-09
Ohlsson, H., Rydell, J., Brun, A., Roll, J., Andersson, M., Ynnerman, A. & Knutsson, H. (2008). Enabling Bio-Feedback using Real-Time fMRI. In: 47th IEEE Conference on Decision and Control, 2008, CDC 2008: . Paper presented at 47th IEEE Conference on Decision and Control, Cancun, Mexico, December, 2008 (pp. 3336-3341). IEEE
Open this publication in new window or tab >>Enabling Bio-Feedback using Real-Time fMRI
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2008 (English)In: 47th IEEE Conference on Decision and Control, 2008, CDC 2008, IEEE , 2008, p. 3336-3341Conference paper, Published paper (Refereed)
Abstract [en]

Despite the enormous complexity of the human mind, fMRI techniques are able to partially observe the state of a brain in action. In this paper we describe an experimental setup for real-time fMRI in a bio-feedback loop. One of the main challenges in the project is to reach a detection speed, accuracy and spatial resolution necessary to attain sufficient bandwidth of communication to close the bio-feedback loop. To this end we have banked on our previous work on real-time filtering for fMRI and system identification, which has been tailored for use in the experiment setup. In the experiments presented the system is trained to estimate where a person in the MRI scanner is looking from signals derived from the visual cortex only. We have been able to demonstrate that the user can induce an action and perform simple tasks with her mind sensed using real-time fMRI. The technique may have several clinical applications, for instance to allow paralyzed and "locked in" people to communicate with the outside world. In the meanwhile, the need for improved fMRI performance and brain state detection poses a challenge to the signal processing community. We also expect that the setup will serve as an invaluable tool for neuro science research in general.

Place, publisher, year, edition, pages
IEEE, 2008
Series
IEEE Conference on Decision and Control. Proceedings, ISSN 0191-2216
Keywords
fMRI, System identification, Bio-feedback
National Category
Engineering and Technology Control Engineering
Identifiers
urn:nbn:se:liu:diva-44641 (URN)10.1109/CDC.2008.4738759 (DOI)000307311603077 ()77222 (Local ID)978-1-4244-3123-6 (ISBN)e-978-1-4244-3124-3 (ISBN)77222 (Archive number)77222 (OAI)
Conference
47th IEEE Conference on Decision and Control, Cancun, Mexico, December, 2008
Note

©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Henrik Ohlsson, Joakim Rydell, Anders Brun, Jacob Roll, Mats Andersson, Anders Ynnerman and Hans Knutsson, Enabling Bio-Feedback Using Real-Time fMRI, 2008, Proceedings of the 47th IEEE Conference on Decision and Control, 2008, 3336.

Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2015-10-08Bibliographically approved
Rydell, J., Knutsson, H., Johansson, A., Dahlqvist Leinhard, O. & Borga, M. (2008). MRI Phase Unwrapping with Application to Water/Fat Separation. In: Proceedings of the SSBA Symposium on Image Analysis,2008: (pp. 27-30).
Open this publication in new window or tab >>MRI Phase Unwrapping with Application to Water/Fat Separation
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2008 (English)In: Proceedings of the SSBA Symposium on Image Analysis,2008, 2008, p. 27-30Conference paper, Published paper (Other academic)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-43052 (URN)71167 (Local ID)71167 (Archive number)71167 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2019-06-14
Leinhard, O. D., Johansson, A., Rydell, J., Smedby, Ö., Nystöm, F., Lundberg, P. & Borga, M. (2008). Quantitative Abdominal Fat Estimation Using MRI. In: Proceedings - International Conference on Pattern Recognition: . Paper presented at 19th International Conference on Pattern Recognition, Tampa FL USA, 8-11 Dec. 2008 (pp. 1-4). IEEE Computer Society
Open this publication in new window or tab >>Quantitative Abdominal Fat Estimation Using MRI
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2008 (English)In: Proceedings - International Conference on Pattern Recognition, IEEE Computer Society, 2008, p. 1-4Conference paper, Published paper (Refereed)
Abstract [en]

This paper introduces a new method for automaticquantification of subcutaneous, visceral and nonvisceralinternal fat from MR-images acquired usingthe two point Dixon technique in the abdominal region.The method includes (1) a three dimensionalphase unwrapping to provide water and fat images, (2)an image intensity inhomogeneity correction, and (3) amorphon based registration and segmentation of thetissue. This is followed by an integration of the correctedfat images within the different fat compartmentsthat avoids the partial volume effects associated withtraditional fat segmentation methods. The method wastested on 18 subjects before and after a period of fastfoodhyper-alimentation showing high stability andperformance in all analysis steps.

Place, publisher, year, edition, pages
IEEE Computer Society, 2008
Series
International Conference on Pattern Recognition, ISSN 1051-4651
National Category
Medical Laboratory Technologies
Identifiers
urn:nbn:se:liu:diva-21108 (URN)10.1109/ICPR.2008.4761764 (DOI)000264729001041 ()978-1-4244-2174-9 (ISBN)978-1-4244-2175-6 (ISBN)
Conference
19th International Conference on Pattern Recognition, Tampa FL USA, 8-11 Dec. 2008
Available from: 2009-09-29 Created: 2009-09-29 Last updated: 2025-02-09Bibliographically approved
Rydell, J., Borga, M. & Knutsson, H. (2008). Robust Correlation Analysis with an Application to Functional MRI. In: Acoustics, Speech and Signal Processing, 2008. ICASSP 2008. IEEE: . Paper presented at IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2008, 31 March-4 April 2008, Las Vegas, NV, USA (pp. 453-456). IEEE conference proceedings
Open this publication in new window or tab >>Robust Correlation Analysis with an Application to Functional MRI
2008 (English)In: Acoustics, Speech and Signal Processing, 2008. ICASSP 2008. IEEE, IEEE conference proceedings, 2008, p. 453-456Conference paper, Published paper (Refereed)
Abstract [en]

Correlation is often used to measure the similarity between signals and is an important tool in signal and image processing. In some applications it is common that signals are corrupted by local bursts of noise. This adversely affects the performance of signal recognition algorithms. This paper presents a novel correlation estimator, which is robust to locally corrupted signals. The estimator is generalized to multivariate correlation analysis (general linear model, GLM, and canonical correlation analysis, CCA). Synthetic functional MRI data is used to demonstrate the estimator, and its robustness is shown to increase the performance of signal detection.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2008
Series
IEEE International Conference on Acoustics, Speech and Signal Processing. Proceedings, ISSN 1520-6149
Keywords
biomedical MRI, correlation methods, medical signal processing, signal detection, canonical correlation analysis, correlation estimator, general linear model, locally corrupted signals, multivariate correlation analysis, robust correlation analysis, synthetic functional MRI data
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-12660 (URN)10.1109/ICASSP.2008.4517644 (DOI)000257456700114 ()978-1-4244-1483-3 (ISBN)e-978-1-4244-1484-0 (ISBN)
Conference
IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2008, 31 March-4 April 2008, Las Vegas, NV, USA
Note

©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Joakim Rydell, Magnus Borga and Hans Knutsson, Robust Correlation Analysis with an Application to Functional MRI, 2008, IEEE International Conference on Acoustics, Speech and Signal Processing, 2008, Las Vegas, USA, 453-456. http://dx.doi.org/10.1109/ICASSP.2008.4517644

Available from: 2007-11-07 Created: 2007-11-07 Last updated: 2015-10-09
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