Vascular ultrasound imaging with flexible wearable array

Abstract Continuous vascular imaging is critical for the early diagnosis and monitoring of disease progression. Vascular ultrasound imaging is usually performed by an array with a high central frequency due to its better imaging quality. However, conventional ultrasonic arrays are rigid and operator-dependent. Existing flexible and wearable ultrasonic arrays are often manufactured with a relatively low central frequency since the element pitch is still limited by processing difficulties. Moreover, the lack of an acoustic lens, matching layer and backing layer also affects performance. Here, we report a 128-channel flexible wearable ultrasonic array designed with a 10 MHz central frequency, 150 μm pitch, shielding layer, backing layer, piezoelectric layer and matching layer. The array has been tested in several ultrafast vascular ultrasound imaging situations, with multi-angle coherent plane-wave transmission adopted. In vitro phantom experiments illustrate its effectiveness in power Doppler and color Doppler imaging of blood flow. Cross-sectional and longitudinal section imaging of the human carotid artery in vivo can be achieved, and Doppler imaging as well as pulsatility measurements have been performed to obtain hemodynamics. Furthermore, long-term continuous ultrasound monitoring of the human carotid artery has been performed over 9 h using the wearable array. Preliminary in vivo ultrasound localization microscopy results for rabbit brain carried out with the array indicate its potential in microvascular imaging. This wearable ultrasonic array will offer more flexibility for ultrasound vascular imaging detection and diagnosis.