[alphaoverlord]

It is not true that ultrasound is used to power pacemakers. Citation definitely needed.

[sergers]

Found a press release from 2013 that research is being performed with ultrasound charging of cardiac/in body devices

http://www.newswise.com/articles/tune-in-turn-on-power-up

The Arizona research company is piezo energy technologies. http://gopiezo14.com

2011 patent: https://www.google.com/patents/US8082041

2014 patent: https://www.google.com/patents/US8974366

But I haven't seen anything commercially available in the medical industry

[alphaoverlord]

All three links are about the same small startup that is being funded by SBIR through the NIH, which is all about trying to give seed funding for experimental technology. The patents are listed on their website and links don't show anything more advanced than ubeam.

[learc83]

No, it's not more advanced, but it was filed several years before ubeam's first patent.

[Animats]

That's direct-contact transmission at very short range: "an acoustic energy emitting device is disposed on coupling medium which in turn is disposed against skin surface. The coupling medium may comprise carageenan, xanthum gum, alginic acid, silicon gel, or other acoustic impedance matching material that is suitable for long-term skin contact." With a viscous gel, as used for ultrasonic medical scanning, efficiency is much better than through air.