# Development of a highly sensitive optically pumped atomic magnetometer for biomagnetic field measurements: A phantom study

Shuji Taue, Yasuyuki Sugihara, Tetsuo Kobayashi, Sunao Ichihara, Kiyoshi Ishikawa, Natsuhiko Mizutani

Research output: Contribution to journalArticle

24 Citations (Scopus)

### Abstract

We developed a highly sensitive optically pumped atomic magnetometer for measuring biomagnetic fields from the human body noninvasively. The sensor head was a cubic Pyrex glass cell containing potassium metal and buffer gases. A pump laser beam for spin-polarizing potassium atoms and a probe laser beam for detecting magneto-optical rotation crossed at right angles in the cell, which was heated in an oven to vaporize potassium atoms. The sensitivity of the magnetometer reached to 10100 $\hbox{fT/Hz}^{1/2}$ at frequencies below several hundred hertz. To test system performance, we made a phantom which models the human brain, taking into account the contribution of distributed electric currents. First, we tested the phantom by a 306-channel whole-head MEG system and confirmed good agreement of the measured field distributions with theoretical calculations. Subsequently, we measured magnetic field distribution with the phantom scanning two-dimensionally above the oven. The signal source location was estimated by least squares fitting to the measured distribution. The goodness of fit value between the measured and the theoretical distributions was 97.9%.

Original language English 5458052 3635-3638 4 IEEE Transactions on Magnetics 46 9 https://doi.org/10.1109/TMAG.2010.2048576 Published - Sep 2010 Yes

### Fingerprint

Magnetometers
Potassium
Ovens
Laser beams
Optical rotation
Atoms
Electric currents
Brain
Buffers
Gases
Metals
Pumps
Magnetic fields
Scanning
Glass
Sensors

### Keywords

• Atomic magnetometer
• Biomagnetic field
• Optical pumping
• Phantom measurement

### ASJC Scopus subject areas

• Electrical and Electronic Engineering
• Electronic, Optical and Magnetic Materials

### Cite this

Development of a highly sensitive optically pumped atomic magnetometer for biomagnetic field measurements : A phantom study. / Taue, Shuji; Sugihara, Yasuyuki; Kobayashi, Tetsuo; Ichihara, Sunao; Ishikawa, Kiyoshi; Mizutani, Natsuhiko.

In: IEEE Transactions on Magnetics, Vol. 46, No. 9, 5458052, 09.2010, p. 3635-3638.

Research output: Contribution to journalArticle

Taue, Shuji ; Sugihara, Yasuyuki ; Kobayashi, Tetsuo ; Ichihara, Sunao ; Ishikawa, Kiyoshi ; Mizutani, Natsuhiko. / Development of a highly sensitive optically pumped atomic magnetometer for biomagnetic field measurements : A phantom study. In: IEEE Transactions on Magnetics. 2010 ; Vol. 46, No. 9. pp. 3635-3638.
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AU - Ishikawa, Kiyoshi

AU - Mizutani, Natsuhiko

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