Fetal magnetocardiography: clinical relevance and feasibility

We investigated the feasibility of a high-Tc SQUID system for fetal magnetocardiography (fetal MCG) aiming at a system without a magnetically shielded room and cooled by a cryocooler. The targeted SQUID resolution was 50 fT/vHz (1–100 Hz). The research was performed along three lines: environmental noise suppression, cooling and low-Tc experiments. Environmental noise can be suppressed by forming second-order gradiometers from individual magnetometers. Concerning cooling, we investigated the applicability of commercially available coolers. In the low-Tc experiments, the medical relevance of fetal MCG was clearly shown. However, they also indicated that, in order to fully exploit the medical potential, the targeted resolution has to be 10 fT/vHz. This increased resolution, in combination with the required high reliability of the sensors, will be hard to realize in high-Tc technology. This paper describes the results of the project and discusses the feasibility of a clinical system.