Novel use of a lung ultrasound sensor for detection of lung interstitial syndrome

The number and distribution of lung ultrasound (LUS) imaging artifacts—B-lines—is correlated with the presence of lung interstitial syndrome such as viral infection, acute respiratory distress syndrome, and pulmonary edema. The detection and quantification of B-lines requires specific training and is machine and operator dependent. In select clinical scenarios continuous hands-free monitoring of lung function is preferred, e.g., COVID-19 infection. The goals of this work were to: (1) identify RF signal features associated with B-lines and (2) develop a single-element, wearable, automated non-imaging lung ultrasound sensor (LUSS) for continuous monitoring. Verasonics Ultrasound Engine with a phased array probe (4.5 MHz) was used to perform standard 10-zone LUS in ten patients with confirmed pulmonary edema, and in five healthy volunteers. The RF data corresponding to each B-mode image and a series of 35 plane wave acquisitions were collected for off-line Doppler, decorrelation, and spectral analyses. B-line thickness and number were associated with peaks of Doppler power at the pleural line. Ten 10 × 5 mm2 5 MHz LUSS, powered by custom-built multiplexed transmit-receive circuit, were fabricated and tested with the same Doppler sequence and signal processing in a lung-mimicking sponge phantom containing variable volumes of water. [Work supported by NIH R01EB023910.]