Good luck on the sleep study!! That sucks you've had to wait so long.

There are a few diff types of sleep machines. The one I have is called an APAP machine (Automatic Positive Airway Pressure). It's about the size of a small laptop, very lightweight. It has a 4' plastic tube that connects from the machine to my sleep mask (there are many types of these; I had to try 2 before I found one that worked for me). After I was diagnosed, my Sleep Dr had the pharmacy (who sells the machines) set the range of air pressure from 4-18 (4 being if I wear the mask while watching tv, wide awake, no need for oxygen pressure increase). 18 is the maximum level of oxygen that can be sent to my mask and pushed into my airways. Different ppl need different numbered settings.

So for example, as soon as I put on my mask, a sensor in the machine notes it, and immediately causes the mask to suction to my face (doesn't hurt, just takes awhile to get used to). Once I fall asleep, the machine continues delivering air pressure through my mask. If my throat/airways are fully open, the pressure stays at 4. If my airways start to collapse (all of this in my sleep, while I'm unconscious), the machine automatically bumps up the pressure of the oxygen so my lungs/brain are getting adequate airflow (hence the term "Auto" in APAP). Essentially the machine does for me in my sleep what my body can't adequately do. The nice thing about the long hose is you can twist and turn anyway you wish, and there's no worries about it not reaching.

Also the machine is very quiet; it makes a barely audible, "Whirr"/whistle sound; my bf doesn't hear it and he sleeps next to me. The machines online are very expensive, like $1000, but through one's pharmacy the price can be cut in half.

I hope I answered you question. If not, or if you have more, don't hesitate to ask!