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Conformable Phased Array Ultrasound Patch for Bladder Volume Monitoring (cUSB-Patch)

Ultrasound can be used to image soft tissues in Vivo for early diagnosis and monitoring of disease progression. However, conventional ultrasound probes are rigid, pressure-required, and operator-dependent. Conformable transducers have been proposed, but they lack the efficiency of element localization and spatial resolution during mechanical deformations for effective diagnostic imaging. Here, we report a conformable ultrasound bladder patch that is based on multiple phased arrays embedded in a stretchable substrate and can provide mechanically robust, conformable, and in vivo volumetric organ monitoring. The phased arrays are fabricated using Sm/La-doped Pb(Mg1/3Nb2/3)O3-PbTiO3(Sm/La-PMN-PT) ceramics as the piezoelectric material, which offers superior properties (d33= 1,000 pC/N, εr= 7,500,k33= 0.77), compared with conventional piezoelectric ceramics. We used the conformable ultrasound patch in a pilot clinical study of bladder monitoring. Bladder volume estimation with the patch is comparable (relative error of 3.2 ± 6.4% and 10.8 ± 8.2%, with and without ultrasound gel, respectively) to that obtained using standard clinical ultrasound equipment, while not requiring manual translation or rotation by an operator.

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Contributors: Lin Zhang, Colin Marcus, David Mejorado, Sara V. Fernandez, David Sadat, Ikra Shuvo, and Canan Dagdeviren