Will 802.11n be used in a portable battery operated medical device?

Power consumption for 802.11n devices will be significantly higher that for 802.a/g devices which are much higher than 802.11b devices. The key reasons why power consumption of 802.11a/g devices was much higher than 802.11b were (a) a more complex signal processing block consuming a lot more power, and (b), a much higher peak-to-average ratio of transmit signal resulting in a more inefficient power amplifier (PA), and therefore a lot more power consumption in the PA to maintain the same output signal. A 802.11g PA can take as much as half an amp at full power, to drive 50-100mW out. For 802.11n devices these issues are multiplied:  There is an order of magnitude more digitial processing in both the TX and RX chains, so a lot more power is consumed here; there is more signal integrity required in the PA chain so it will correspondingly be less efficient; and there are 2 or 3 radios that need to talk to the 2 or 3 antennas and so the power gets multiplied by that factor. Don't look for 802.11n to be coming to the low power requirements of telemetry transmitters or any other small form factor low power required patient monitor, pulse oximeter or infusion device.