Conformal Ultrasound Transducer Array for Image-Guided Neural Therapy

The paper discusses the design and validation of a novel wearable conformal ultrasound array with integrated imaging and modulation capabilities. A custom 64-element linear PZT array with 5 MHz resonance frequency was used for imaging. An 8-element linear array using larger PZT elements for efficient power transfer was also integrated on the wearable probe to enable image-guided neural modulation. Full-wave simulations were used to estimate the generated pressure field at various depths. Vagus nerve modulation using low intensity focused ultrasound is an important field that is targeted in this study, so the relevant focal depth (10-20 mm) was considered for both imaging and modulation array designs. A carotid artery localization algorithm was developed to easily locate the vagus nerve for imaging and modulation. A curvature estimation method based on flexible strain sensors integrated on the probe was also developed for real-time optimization of the image processing and beamforming algorithms. Preliminary measurement and characterization results of a rigid prototype show promising results with ~2.5 MHz bandwidth.