Biomagnetic multichannel system with integrated SQUIDs and first order gradiometers operating in a shielded room
✍ Scribed by H.E. Hoenig; G. Daalmans; W. Folberth; H. Reichenberger; S. Schneider; H. Seifert
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- English
- Weight
- 563 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0011-2275
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✦ Synopsis
This paper deals with the description of and the first results obtained with a 30 channel system for biomagnetic diagnosis of the human body. The system consists of a liqui.d helium cooled sensor array, enclosed in a fibreglass cryostat, located in a magnetically shielded room with a moderate shielding factor, suspended by a manipulator allowing the positioning of the sensor array relative to the biomagnetic source. The sensor array consists of d.c. SQUIDs coupled to an array of gradiometers. The gradiometers are of the axial first order type. The SQUID array consists of planar Ketchen type SQUIDs integrated on a silicon wafer. The SQUIDs are operated in the flux locked loop mode. The overall system performance with a fully activated sensor array is typically 20 fT Hz -1/2. There is now'a practical tool for research and functional diagnosis of the brain and the heart, measuring the spatial dependence of biomagnetic fields in parallel on sufficiently large scale. Examples of simultaneous recordings of standard and high resolution magnetocardiograms are presented.