  Bladder volume measurement is critical for early detection and management of
lower urinary tract dysfunctions. The current gold standard is invasive, and
alternative technologies either require trained personnel or do not offer
medical grade information. Here, we report an integrated wearable ultrasonic
bladder volume monitoring (UBVM) device for accurate and autonomous continuous
monitoring of the bladder volume. The device incorporates flexible and
air-backed ultrasonic transducers and miniaturized control electronics with
wireless data transmission capability. We demonstrated the real-life
application of the device on healthy volunteers with various bladder shapes and
sizes with high accuracy. Apart from the lower urinary tract dysfunctions, the
proposed technology could also be adapted for various wearable ultrasonic
applications.
