A wearable non-invasive sonogenetic pacemaker

Key Points:

• A novel sonogenetics-based cardiac pacemaker system uses focused ultrasound to activate mechanosensitive ion channels (MscL-G22S) in cardiomyocytes, enabling non-invasive myocardial pacing through Ca2+ influx and contraction.
• Compared to traditional light-based stimulation, ultrasound exhibits significantly lower attenuation (-15 dB vs. over -55 dB at 30 mm depth), allowing more effective energy delivery from the chest skin to heart tissue.
• The NUP system integrates a 64-channel transmitter, 32-channel receiver, FPGA digital beamforming, Wi-Fi, and USB connectivity, supporting combined imaging and stimulation modes with controlled power consumption.
• Experimental results in rodents demonstrate ultrasound-induced modulation of cardiac activity, showing significant changes in ECG components and heart rate at acoustic pressures between 2.03 and 3.837 MPa, confirming effective pacing stimulation.
• Tissue-specific expression analysis of MscL-G22S reveals predominant localization in cardiac ventricles and atria, with minimal expression in non-cardiac tissues, supporting targeted ultrasonic pacing with reduced off-target effects.