Ultrasound on Smartphones and Tablets

More sensor developments we need to watch.   Directly how practical and accurate remains to be seen.  " ... Qualcomm, in the fourth quarter of 2012, acquired the assets of EPOS, a developer of digital ultrasound technology. Qualcomm plans to incorporate the technology into chips that would go into not only mobile devices but also wearable electronics. Ultrasound could facilitate the use of a stylus as an input device and gesture recognition for smartphones and tablet computers, according to this article ... "