OSE Seminar by Dr. Peter Schwindt on A multi-channel magnetoencephalography system using optically pumped magnetometers
Posted: November 16, 2020
Date: Thursday, November 19, 2020
Time: 12:15 PM to 1:15 PM
Location: via Zoom
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We have developed a complete MEG system including a person-sized magnetic shield and a 24-channel array of OPMs. The array consists of six 4-channel sensor modules where the channels within each sensor are spaced by 18 mm and each sensor covers a 40 mm by 40 mm area of the head. The sensitivity of the magnetometer channels inferred from gradiometric measurements is < 5 fT/Hz1/2 over a frequency range of 5 to 100 Hz. The array is placed over the left side of the head. We have used the array to measure signals from auditory and somatosensory stimulation, and we have demonstrated the localization of magnetic sources in the auditory and somatosensory cortices using a dipole fitting routine. Current research is focused on improving the performance of the system, in particular evaluating the stability of the gain and of the angle of the field component measured by each magnetometer channel. We are also working to precisely calibrate the location of each sensor. I will present results on the performance of our OPM array in the person-sized shield and preliminary studies with human subjects.
Dr. Peter Schwindt is a Distinguished Member of the Technical Staff at Sandia National Laboratories and has been engaged in optical and atomic physics research since 1997 with an emphasis in applying the principles of atomic physics to sensing and timing problems. One of his primary focus areas is optically pumped (atomic) magnetometers (OPMs), developing techniques to both miniaturize them and improve their sensitivity and bandwidth. Since 2007, he led a project to develop OPMs for application to magnetoencephalography. Dr. Schwindt has also worked on multiple atomic clock projects, developing trapped Yb ion microwave and optical clocks, focusing on techniques for miniaturization and low-power-consumption maintaining excellent long-term frequency stability. Dr. Schwindt has also led a project to miniaturize and extend the dynamic range of an atom interferometer accelerometer while developing a photonic-integrated-circuit-based laser system. Prior to coming to Sandia National Laboratories in 2006, Dr. Schwindt worked as a National Research Council post-doctoral fellow at the National Institute of Standards and Technology. His research there focused on the development of chip-scale atomic clocks and magnetometers. He received his Ph.D. in 2003 from the University of Colorado at Boulder.