“…In this context, the feasibility of an apparatus for the measurement of the magnetic signal of the fetal heart was considered. Towards the development of such a fetal heart monitor, the suitability of cryocoolers for cooling a high-T c SQUID gradiometer was evaluated [1,2]. The Cryotiger Ò cooler was selected for this purpose because of the low interference level that was expected based on literature and introductory experiments [2][3][4][5][6].…”