I've used the at-home system for a at-home sleep study. If you have obstructive sleep apnea, these at-home systems will likely spot it. If your sleep is being disturbed by a brain activity issue, they won't.

The system I used had a band around your chest to measure chest rise, and a pulse oximeter to measure heartbeat and oxygen saturation in the blood. It recorded both chest rise and pulse/O2 saturation for the entire night, then I took the whole unit into the MD's office, where they offloaded the data and made a diagnosis.