Healthcare sensors

Two Ideas for outpatient healthcare
1. Bluetooth headset for chewing problem detection, ISWPC 2008, Greece
2. In-bed accelerometer sensors for sleeping patterns identification,
Pervasive Health 2008, Finland (software now also available on i-Phone as
paid download)

I like their ideas of using widely available Bluetooth headset and i-Phone
instead of expensive medical equipment. But I do not have signal processing
background to make judgments.