MRI-Integrated Devices

Adaptive and wireless recordings of electrophysiological signals during concurrent MRI

(Mandal, Babaria, Cao, Liu. IEEE Trans. Biomed. Engr., 2018)

GIF of Typical MRI image formation
Strong electromagnetic fields during functional magnetic resonance imaging (fMRI) presents a challenging environment for any concurrent electrophysiological recording. Here, we present a miniaturized, wireless platform – “MR-Link” (Multimodal Recording Link) that provides a hardware solution for simultaneous electrophysiological and fMRI signal acquisition. The device detects changes in the electromagnetic field during fMRI and synchronizes amplification and sampling of electrophysiological signals to minimize effects of gradient and RF artifacts. It wirelessly transmits the recorded data at a frequency detectable by the MR-receiver coil. The transmitted data is readily separable from MRI in the frequency domain. To demonstrate its efficacy, we used this device to record electrocardiograms and somatosensory evoked potential without artifacts from concurrent fMRI scans, or compromising imaging quality. The compact recording device (20 mm dia., 2gms) placed within the MR-bore minimized movement artifacts and achieved microsecond-level synchronization with fMRI data. MR-Link offers an inexpensive system to eliminate the need for amplifiers with high dynamic range or sampling rate, high-power sampling, additional storage or synchronization hardware to connect with the MR-scanner. This device is expected to enable easier and a broader range of applications of simultaneous fMRI and electrophysiology in animals and humans.

MRI-Compatible EEG recordings with miniaturized wireless devices

(Mandal, Babaria, Cao, Liu. 2017. ISMRM, Magna Cum Laude Award)

Picture of MRI-Compatible EEG recordings with miniaturized wireless devices

The MR-integrated system provides a simple solution for high fidelity neural recording in simultaneous fMRI studies by utilizing MR-surplus hardware. Gradient triggered sampling and analog switching circuit combined with wireless reception of EEG signal by MR coil address technical challenges regarding the signal integrity and electromagnetic artifacts, while reducing the overall complexity by removing the dependence on bulky synchronization and shielding systems. Additionally, further refinement and implementation of the system will be focused on future human applications. Therefore, the success of the current research is expected to open new avenues for widely accessible, integrative neuroimaging tools.