Microwave Pilot Tone: Coil Array with Integrated RF Mixing for Efficient Motion Sensing

Motivation: To develop a more efficient, sensitive and integrated solution to current motion sensing techniques. Goal(s): Demonstrate a mixer-on-coil approach to motion sensing that allows for freedom in choice of RF frequency without relying on the scanner's hardware. Approach: We incorporate mixers onto receivers coils to efficiently mix down motion modulated high frequency signals into a tone that lies within the receiver's bandwidth and compare its performance to Pilot Tone (PT). Results: In cardiac and respiratory motion sensing, μPT demonstrates a x3-4 increase in percent modulation when compared to PT, aligning closely with PPG and bellow recordings with minimal impact on the noise floor. Impact: μPT would enable efficient, higher sensitivity to motion at arbitrary frequencies, by leveraging on-coil mixing and minimizing cabling.