55 citations · 139 across the 8 of their papers we have counts for
8 papers
A general method for computing thermal magnetic noise arising from thin conducting objects
Joonas Iivanainen, Antti J. Mäkinen, Rasmus Zetter +3
Thermal motion of charge carriers in a conducting object causes magnetic field noise that interferes with sensitive measurements nearby the conductor. In this paper, we describe a…
Spatial sampling of MEG and EEG revisited: From spatial-frequency spectra to model-informed sampling
Joonas Iivanainen, Antti J. Mäkinen, Rasmus Zetter +3
In this paper, we analyze spatial sampling of electro- (EEG) magnetoencephalography (MEG), where the electric or magnetic field is typically sampled on a curved surface such as the…
Magnetic-field modeling with surface currents: Physical and computational principles of bfieldtools
Antti J. Mäkinen, Rasmus Zetter, Joonas Iivanainen +3
Surface currents provide a general way to model static magnetic fields in source-free volumes. To facilitate the use of surface currents in magneto-quasistatic problems, we have im…
Magnetic-field modeling with surface currents: Implementation and usage of bfieldtools
Rasmus Zetter, Antti J. Mäkinen, Joonas Iivanainen +3
We present a novel open-source Python software package, bfieldtools, for magneto-quasistatic calculations with current densities on surfaces of arbitrary shape. The core functional…
Evaluating the Performance of Ultra-Low-Field MRI for In-vivo 3D Current Density Imaging of the Human Head
Peter Hömmen, Antti J. Mäkinen, Alexander Hunold +5
Magnetic fields associated with currents flowing in tissue can be measured non-invasively by means of zero-field-encoded ultra-low-field magnetic resonance imaging (ULF MRI) enabli…
Sampling theory for spatial field sensing: Application to electro- and magnetoencephalography
Joonas Iivanainen, Antti Mäkinen, Rasmus Zetter +3
We present a theoretical framework for analyzing spatial sampling of fields in three-dimensional space. The framework bridges Shannon's sampling and information theory to Bayesian…
Automatic Spatial Calibration of Ultra-Low-Field MRI for High-Accuracy Hybrid MEG--MRI
Antti J. Mäkinen, Koos C. J. Zevenhoven, Risto J. Ilmoniemi
With a hybrid MEG--MRI device that uses the same sensors for both modalities, the co-registration of MRI and MEG data can be replaced by an automatic calibration step. Based on the…
Superconducting receiver arrays for magnetic resonance imaging
Koos C. J. Zevenhoven, Antti J. Mäkinen, Risto J. Ilmoniemi
Superconducting QUantum-Interference Devices (SQUIDs) make magnetic resonance imaging (MRI) possible in ultra-low microtesla-range magnetic fields. In this work, we investigate the…