Wireless In-Bore Ballistocardiography with 2.4GHz Beat Pilot Tone (BPT)

We previously proposed the Beat Pilot Tone (BPT), a motion sensing method that uses microwave frequencies and preamplifier intermodulation to obtain increased motion sensitivity compared to Pilot Tone (PT). Here, we show that cardiac signals acquired with BPT correlate strongly with displacement ballistocardiograms (dBCG). We compare the BPT signals to dBCG acquired with an accelerometer. Additionally, we show that BPT has greater signal modulation compared to PT in sensing cardiac motion. BPT could be a novel, non-contact, and wireless method for acquiring dBCG signals, offering robustness in setup for patients and rich physiological information complementary to the MRI exam.