A Low-noise Multichannel Magnetocardiogram System for the Diagnosis of Heart Electric Activity
1
조회
0
다운로드
1
인용
0
참고문헌
초록
Abstract
A 64-channel magnetocardiogram (MCG) system using low-noise superconducting quantum interference device (SQUID) planar gradiometers was developed for the measurements of cardiac magnetic fields generated by the heart electric activity. Owing to high flux-to-voltage transfers of double relaxation oscillation SQUID (DROS) sensors, the flux-locked loop electronics for SQUID operation could be made simpler than that of conventional DC SQUIDs, and the SQUID control was done automatically through a fiber-optic cable. The pickup coils are first-order planar gradiometers with a baseline of 4 cm. The insert has 64 planar gradiometers as the sensing channels and were arranged to measure MCG field components tangential to the chest surface. When the 64-channel insert was in operation everyday, the average boil-off rate of the dewar was 3.6 L/d. The noise spectrum of the SQUID planar gradiometer system was about 5 fTrms/√Hz at 100 Hz, operated inside a moderately shielded room. The MCG measurements were done at a sampling rate of 500 Hz or 1 kHz, and realtime display of MCG traces and heart rate were displayed. After the acquisition, magnetic field mapping and current mapping could be done. From the magnetic and current information, parameters for the diagnosis of myocardial ischemia were evaluated to be compared with other diagnostic methods.
참고문헌 (12)
- "Magnetism in Medicine", pp.136~189 (1998)
- "Magnetism in Medicine", pp.85~135 (1998)
- "Qualitative and Quantitative Description of Myocardial Ischemia by means of magnetocardiography", 49, pp.267~273 (2004)
- "Clinical application of magnetocardiography", 5, pp.291~313 (2005)
- "Magnetocardiograms in clinical medicine unique information on cardiac ischemia", 44, pp.1~19 (2005)
- "SQUID systems for biomagnetic imaging", 12, pp.79~114 (2001)
- "relaxation oscillation SQUIDs with high flux-to-voltage transfer", 76, pp.3875~3886 (1994)
- "Double relaxation oscillation SQUID with reference junction for biomagnetic multi-channel applications", 5, pp.413~418 (1998)
- "64-channel magnetocardiogram system based on double relaxation oscillation SQUID planar gradiometers", 19, pp.284~288 (2006)
- "Compact readout electronics for 62-channels DROS magnetocardiography system", 15, pp.644~647 (2005)
- "Optimal sensor distribution for measuring the tangential field components in MCG", pp.359~360 (2004)
- "Transformation of multichannel magnetocardiographic signals to standard grid form", 42, pp.72~78 (1995)