Progress in Superconductivity

The Korean Superconductivity Society (한국초전도학회)
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The characteristics of DROS magnetometer and MCG measurement

DROS 자력계의 동작특성 및 심자도 측정

  • Kang, C.S. (Department of Physics, Korea University) ;
  • Lee, Y.H. (Bio-signal Research Center, Korea Research Institute of Standards and Science) ;
  • Kwon, H. (Bio-signal Research Center, Korea Research Institute of Standards and Science) ;
  • Kim, J.M. (Bio-signal Research Center, Korea Research Institute of Standards and Science) ;
  • Yu, K.K. (Bio-signal Research Center, Korea Research Institute of Standards and Science) ;
  • Park, Y.K. (Bio-signal Research Center, Korea Research Institute of Standards and Science) ;
  • Lee, S.G. (Department of Physics, Korea University)
  • Published : 2007.04.30
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Abstract

We developed a SQUID magnetometer based on Double Relaxation Oscillation SQUID(DROS) for measuring magnetocardiography(MCG). Since DROS provides a 10 times larger flux-to-voltage transfer coefficient than the conventional DC-SQUID, simple flux-locked loop electronics could be used for SQUID operation. Especially, we adopted an external feedback to eliminate the magnetic coupling with adjacent channels. When the DROS magnetometer was operated inside a magnetically shielded room, average magnetic field noise was about 5 $fT/^{\surd}Hz$ at 100 Hz. Using the DROS magnetometer, we constructed a multichannel MCG system. The system consisted of 61 magnetometers are arranged in a hexagonal structure and measures a vertical magnetic-field component to the chest surface. The distance between adjacent channels is 26 mm and the magnetometers cover a circular area with a diameter of 208 mm. We recorded the MCG signals with this system and confirmed the magnetic field distribution and the myocardinal current distribution.

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