One of the biggest limitations holding back battery powered medical devices is the battery power. Most telemetry units are powered by batteries you buy at Walgreens - not very high tech. Other products, with rechargeable batteries use lithium-ion batteries, an improvement but not a big improvement.

Welch Allyn's Propaq LT and Draeger's TeleSmart (more here, scroll down) take a step in the right direction with bedrails that trickle charge the monitors, so they're always at full charge when they go mobile. But many wireless medical devices (and device use cases) are not suited to the recharging cradle. What we need is new dramatically improved battery technology.

MIT spin-off A123 Systems has taken the lithium-ion battery and applied materials science and nanotechnology to the particles that coat the battery's electrodes and store and discharge energy. Results include a doubling of power density, a fivefold jump in peak energy (the cells pack more
punch than a standard 110-volt wall outlet), and recharging time
plummets - the M1 battery takes 5 minutes to achieve a 90% charge. Sweet. Going nano also improves safety. Regular
high-capacity Li-ion batteries can explode under severe stress,
like if they're dropped from several feet, or crushed. Rocket scientists can check out the spec sheet here (pdf).

A123 Systems has yet to announce any deals with medical device vendors, but let's hope that changes soon. Pictured right is the M1 battery.

[Hat tip: Wired]