The Experts below are selected from a list of 62247 Experts worldwide ranked by ideXlab platform
Jens Haueisen - One of the best experts on this subject based on the ideXlab platform.
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reconstruction of quasi radial dipolar activity using three Component Magnetic Field measurements
Clinical Neurophysiology, 2012Co-Authors: Jens Haueisen, K Fleissig, Daniel Strohmeier, Tarek Elsarnagawy, Ralph Huonker, Mario Liehr, Otto W WitteAbstract:Abstract Objective While standard magnetoencephalographic systems record only one Component of the bioMagnetic Field, novel vector-biomagnetometers enable measurement of all three Components of the Field at each sensing point. Because information content in standard one-Component magnetoencephalography (MEG) is often not adequate to reconstruct quasi-radial dipolar activity, we tested the hypothesis that quasi-radial activity can be estimated using three-Component MEG. Methods We stimulated the right median nerve in 11 healthy volunteers and recorded the somatosensory evoked Fields over the contralateral hemisphere using a novel vector-biomagnetometer system comprised of SQUID-based magnetometer triplets. Source reconstruction for the early cortical Components N20m and P25m was subsequently performed. Results Both tangential and quasi-radial dipolar activity could be reconstructed in 10 of the 11 participants. Dipole locations were found in the vicinity of the central sulcus, and dipole orientations were predominantly tangential for N20m and quasi-radial for P25m. The mean location difference between the tangential and quasi-radial dipoles was 11.9 mm and the mean orientation difference was 97.5°. Conclusions Quasi-radial dipolar activity can be reconstructed from three-Component magnetoencephalographic measurements. Significance Three-Component MEG provides higher information content than does standard MEG.
Otto W Witte - One of the best experts on this subject based on the ideXlab platform.
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reconstruction of quasi radial dipolar activity using three Component Magnetic Field measurements
Clinical Neurophysiology, 2012Co-Authors: Jens Haueisen, K Fleissig, Daniel Strohmeier, Tarek Elsarnagawy, Ralph Huonker, Mario Liehr, Otto W WitteAbstract:Abstract Objective While standard magnetoencephalographic systems record only one Component of the bioMagnetic Field, novel vector-biomagnetometers enable measurement of all three Components of the Field at each sensing point. Because information content in standard one-Component magnetoencephalography (MEG) is often not adequate to reconstruct quasi-radial dipolar activity, we tested the hypothesis that quasi-radial activity can be estimated using three-Component MEG. Methods We stimulated the right median nerve in 11 healthy volunteers and recorded the somatosensory evoked Fields over the contralateral hemisphere using a novel vector-biomagnetometer system comprised of SQUID-based magnetometer triplets. Source reconstruction for the early cortical Components N20m and P25m was subsequently performed. Results Both tangential and quasi-radial dipolar activity could be reconstructed in 10 of the 11 participants. Dipole locations were found in the vicinity of the central sulcus, and dipole orientations were predominantly tangential for N20m and quasi-radial for P25m. The mean location difference between the tangential and quasi-radial dipoles was 11.9 mm and the mean orientation difference was 97.5°. Conclusions Quasi-radial dipolar activity can be reconstructed from three-Component magnetoencephalographic measurements. Significance Three-Component MEG provides higher information content than does standard MEG.
A K Vershovskii - One of the best experts on this subject based on the ideXlab platform.
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concept of a microscale vector Magnetic Field sensor based on nitrogen vacancy centers in diamond
Journal of The Optical Society of America B-optical Physics, 2016Co-Authors: Alexander Dmitriev, A K VershovskiiAbstract:A three-Component Magnetic Field sensor scheme based on optically detected Magnetic resonance (ODMR) in negatively charged nitrogen-vacancy centers is implemented and investigated experimentally. The central part of the scheme is a 0.01 mm3 diamond crystal, optically pumped and interrogated through an optical fiber; combined RF excitation of hyperfine triplets in the ODMR spectrum is used to increase the signal-to-noise ratio. Methods that allow for efficient identification of ODMR spectral lines while minimizing the number of the sensor “dead” zones are proposed and tested. The scheme’s sensitivity to Magnetic Field vector Components, estimated on the basis of the signal-to-noise-to-linewidth ratio, is found to be 1.5 nT·Hz−1/2. The operational frequency range of the scheme is 0–100 Hz.
Tarek Elsarnagawy - One of the best experts on this subject based on the ideXlab platform.
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reconstruction of quasi radial dipolar activity using three Component Magnetic Field measurements
Clinical Neurophysiology, 2012Co-Authors: Jens Haueisen, K Fleissig, Daniel Strohmeier, Tarek Elsarnagawy, Ralph Huonker, Mario Liehr, Otto W WitteAbstract:Abstract Objective While standard magnetoencephalographic systems record only one Component of the bioMagnetic Field, novel vector-biomagnetometers enable measurement of all three Components of the Field at each sensing point. Because information content in standard one-Component magnetoencephalography (MEG) is often not adequate to reconstruct quasi-radial dipolar activity, we tested the hypothesis that quasi-radial activity can be estimated using three-Component MEG. Methods We stimulated the right median nerve in 11 healthy volunteers and recorded the somatosensory evoked Fields over the contralateral hemisphere using a novel vector-biomagnetometer system comprised of SQUID-based magnetometer triplets. Source reconstruction for the early cortical Components N20m and P25m was subsequently performed. Results Both tangential and quasi-radial dipolar activity could be reconstructed in 10 of the 11 participants. Dipole locations were found in the vicinity of the central sulcus, and dipole orientations were predominantly tangential for N20m and quasi-radial for P25m. The mean location difference between the tangential and quasi-radial dipoles was 11.9 mm and the mean orientation difference was 97.5°. Conclusions Quasi-radial dipolar activity can be reconstructed from three-Component magnetoencephalographic measurements. Significance Three-Component MEG provides higher information content than does standard MEG.
Daniel Strohmeier - One of the best experts on this subject based on the ideXlab platform.
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reconstruction of quasi radial dipolar activity using three Component Magnetic Field measurements
Clinical Neurophysiology, 2012Co-Authors: Jens Haueisen, K Fleissig, Daniel Strohmeier, Tarek Elsarnagawy, Ralph Huonker, Mario Liehr, Otto W WitteAbstract:Abstract Objective While standard magnetoencephalographic systems record only one Component of the bioMagnetic Field, novel vector-biomagnetometers enable measurement of all three Components of the Field at each sensing point. Because information content in standard one-Component magnetoencephalography (MEG) is often not adequate to reconstruct quasi-radial dipolar activity, we tested the hypothesis that quasi-radial activity can be estimated using three-Component MEG. Methods We stimulated the right median nerve in 11 healthy volunteers and recorded the somatosensory evoked Fields over the contralateral hemisphere using a novel vector-biomagnetometer system comprised of SQUID-based magnetometer triplets. Source reconstruction for the early cortical Components N20m and P25m was subsequently performed. Results Both tangential and quasi-radial dipolar activity could be reconstructed in 10 of the 11 participants. Dipole locations were found in the vicinity of the central sulcus, and dipole orientations were predominantly tangential for N20m and quasi-radial for P25m. The mean location difference between the tangential and quasi-radial dipoles was 11.9 mm and the mean orientation difference was 97.5°. Conclusions Quasi-radial dipolar activity can be reconstructed from three-Component magnetoencephalographic measurements. Significance Three-Component MEG provides higher information content than does standard MEG.