http://hardm.ath.cx:88/pdf/RFpenetrationInTissue.pdf
- from the perspective of NMR imaging.
- gives the penetration depths & phase-shifts for RF waves from 1 - 100Mhz. I can obly assume that it is much worse for 400Mhz and 2.4Ghz.
- that said, Zarlink's MICS transceiver works from the GI tract at 400mhz with low power, suggesting that the attenuation can't be too too great.
- includes equations used to derive these figures.
- document describing how various antenna types are effected by biological tissue, e.g. a human head.
even more interesting: wireless brain machine interface |