High-Voltage Phased Array Electronics for Ultrasound Neuromodulation

An ultrasound (US) phased array with electronic steering and focusing capability can enable high-resolution, large-scale US neuromodulation in basic research and clinical experiments. For such applications in different subjects (animals and humans), phased array electronics should provide flexibility in generating waveforms with different patterns (stimulation parameters), fine delay resolution between channels, and high voltage across US transducers (generating high US pressure output) over an extended duration. This paper presents 16-channel high-voltage phased array electronics for neuromodulation, capable of driving US transducers with up to 150 V pulses and 5 ns delay resolution while providing a wide range of sonication waveforms. The electronics has been integrated with a custom-made 2 MHz, 16-element US transducer array <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(4.3\times 11.7\times 0.7 \text{mm}^{3})$</tex>. In measurements, the phased array system achieved up to 6 MPa peak-to-peak US pressure output at a focal depth of 10 mm with a lateral/axial resolution of 0.6/4.67 mm. The beam focusing/steering capability of the system in measurements and the theoretical analysis of the power consumption of the high-voltage driver (along with measured results) have also been provided.