A seven-channel high- SQUID-based heart scanner

Abstract

We have fabricated a seven-channel magnetometer, equipped with packaged high- SQUIDs. These inductively shunted SQUIDs have a noise level of typically 120 fT down to 1 Hz. A packaging method has been developed and proved to be reliable over a one-year period with at least 25 thermal cycles. The performance of the system was demonstrated by the wide-band recording of seven-channel magnetocardiograms inside a magnetically shielded room.

Fetal magnetocardiography: clinical relevance and feasibility

“…The alumina holder contains three primary measurement SQUIDs and two reference SQUIDs. These are single-layer inductively shunted DC-SQUIDs based on bicrystal grain boundary junctions [16]. The three primary SQUIDs can be combined electronically into a second-order gradiometer with 6 cm baseline.…”

Construction and tests of a heart scanner based on superconducting sensors cooled by small stirling cryocoolers

“…However, to detect anomalies, frequencies up to 100 Hz should be considered. High-T c SQUIDs can be applied to measure magnetocardiograms as we demonstrated in the past with a liquid-nitrogen cooled 7-channel system [5].…”

“…Two SQUID sensors are available, which were previously used in the development of the 7-channel liquidnitrogen cooled system [5]. The intrinsic noise of these SQUIDs is about 0.16 pT/ p Hz.…”

A high-temperature rf SQUID system for magnetocardiography

“…For most diagnostic purposes, multi-channel SQUID systems are required. Several groups reported on HTS SQUID multi-channel systems and have shown examples of MCG signal traces [6][7][8][9].…”