I reported previously (Sep 2015) about Israel’s Augury that uses vibration and ultrasound to detect faults in critical machinery. Now another Israeli startup 3DSignals has developed an ultrasonic acoustic sensor which predicts electro-mechanical failure long before it causes production downtime.
http://www.globes.co.il/en/article-ultrasonic-acoustic-sensor-co-3dsignals-raises-3m-1001155323