HackerPapers

arXiv:2001.03534physics.med-ph

Portable magnetometry for detection of biomagnetism in ambient environments

M. E. Limes, E. L. Foley, T. W. Kornack, S. Caliga, S. McBride, A. Braun, W. Lee, V. G. Lucivero, M. V. Romalis

Early discovery. Linked by one identifiable commenter. This paper is outside the main ranking; a mention is not an endorsement.

Abstract

We present a method of optical magnetometry with parts-per-billion resolution that is able to detect biomagnetic signals generated from the human brain and heart in Earth's ambient environment. Our magnetically silent sensors measure the total magnetic field by detecting the free-precession frequency of highly spin-polarized alkali metal vapor. A first-order gradiometer is formed from two magnetometers that are separated by a 3 cm baseline. Our gradiometer operates from a laptop consuming 5 W over a USB port, enabled by state-of-the-art micro-fabricated alkali vapor cells, advanced thermal insulation, custom electronics, and laser packages within the sensor head. The gradiometer obtains a sensitivity of 16 fT/cm/Hz$^{1/2}$ outdoors, which we use to detect neuronal electrical currents and magnetic cardiography signals. Recording of neuronal magnetic fields is one of a few available methods for non-invasive functional brain imaging that usually requires extensive magnetic shielding and other infractructure. This work demonstrates the possibility of a dense array of portable biomagnetic sensors that are deployable in a variety of natural environments.

arXiv comments
Journal reference
Phys. Rev. Applied 14, 011002 (2020)
DOI
doi:10.1103/PhysRevApplied.14.011002
Subjects
physics.med-phMedical Physics physics.atom-phAtomic Physics physics.ins-detInstrumentation and Detectors

On Hacker News

Linked by 1 identifiable commenter in 3 comments across 3 threads, from Jul 2020 to Oct 2023.

Comments linking this paper, per year.

Discussed in comments3 threads

  1. Apple patents suggest future AirPods could monitor biosignals and brain activity 1 comment

    • Magnetic measurements are both physically possible and don't have muscle interference. For example https://arxiv.org/abs/2001.03534 is a magnetic field sensor that measures brain activity and runs off a USB port. It's probably a couple decades away, but at least it's feasible.

      twargeView on HNParent context

  2. DARPA grant to work on sensing and stimulating the brain noninvasively [video] 1 comment

    • Here's a USB-powered unshielded MEG sensor that you can just carry out into the woods https://arxiv.org/abs/2001.03534 So that's new.

      twargeView on HNParent context

  3. USB-C Brain Reader (Magnetoencephalography by the Pond) 1 comment

    • Preprint: https://arxiv.org/abs/2001.03534 The papers describe a new magnetic field sensor that can measure Brain signals. What's new is that you can do it without a million dollar shielded room. It's just powered by USB-C on a MacBook.

      twargeView on HNParent context

Submitted to Hacker News

Connected through shared HN threads, not inferred similarity or a recommendation.