Vascular Ultrasound Imaging with Flexible Wearable Array

Abstract Continuous vascular imaging is critical for early diagnosis and monitoring of disease progression. Vasculature ultrasound imaging is usually performed by an array with high center frequency due to the advantages in imaging quality. However, conventional ultrasonic arrays are rigid and operator-dependent. The existing flexible and wearable ultrasonic array are often manufactured with relatively low center frequency since the element pitch is still limited by difficulty in processing technic. Moreover, lacking of acoustic lens, matching layer and backing layer also affects its performance. Here, we report a 128-channel flexible wearable ultrasonic array with 10 MHz center frequency, 150μm pitch, shielding layer, backing layer, piezoelectric layer and matching designed. The array has been testified in several ultrafast vascular ultrasound imaging situations, with multi-angle coherent plane-wave transmission adopted. In-vitro phantom experiments have illustrated its effectiveness in power Doppler and color Doppler imaging of blood flow. The cross section and longitudinal section imaging of in-vivo human carotid artery can be achieved, and Doppler imaging as well as pulsatility measurement has been performed to obtain the hemodynamics. Furthermore, long-term continuous ultrasound monitoring of 9 hours is also performed to human carotid artery by the wearable array. In addition, preliminary in-vivo ultrasound localization microscopy (ULM) result of rabbit brain carried out by the array have indicated its potentials in microvascular imaging. This flexible wearable ultrasonic array will offer more opportunities for ultrasound vascular imaging detection and diagnosis.