we had someone from hill-rom come out when we got it. there is also an instructional video. the wrap around vest doesn't give you too many options for placement. the doctors instructions were for 14/4/20min which is similar to what he had when in the hospital. it didn't sounds like they were too set on things and left a little bit up to experimentation. i saw a link to a frequency study a while back, does anyone have that, or some pointers? thanks