We here in Aarhus, Denmark, are in need of a solution for the monitoring, and synchronous acquisition of respiration during MEG recordings (Elekta Triux system). Currently we are considering two solutions, both involving a low-cost pressure transducer coupled to an MR-compatible chest-strapped cushion. The challenge that remains is to sample the output of the transducer, either 

1) using the bipolar EMG/EOG inputs inside the MSR (with appropriate circuit design to allow differential amplification), or 

2) using the AUXiliary channels, which however are located outside the shield, meaning we need an optical isolation circuit and, consequently, pre-amplification of the transducer signal when still inside the MSR

Any pointers to commercial or DIY solutions that allow the inclusion of the respiratory signal into the MEG data stream would be most welcome. 

Best regards,

Chris