Need help in interpreting these results

I've been meaning to get a sleep study done in order to find out whether I have sleep apnea or not, but I decided to try recording my SpO2 and pulse rate myself using a Finger Pulse Oximeter (commonly used in sleep studies as a diagnostic tool) as a less expensive option. I still fully intend to get a sleep study done as soon as possible, though.

Does anyone know what's going on here? These peaks in bpm and drastic drops in SPO2 are a bit disconcerting to see, considering I felt that I slept through the night relatively easily. I vaguely remember having to put the oximeter back on my finger a couple of times during the night (it's easy for it to fall off when you're moving about in your sleep), hence the grey lines.

[IMG]https://dl.dropbox.com/u/17046710/1.png[/IMG]

[IMG]https://dl.dropbox.com/u/17046710/2.png[/IMG]

Bumping with another graph of last night's results. I've really gotta try and keep the damn thing on during the night:

[IMG]https://dl.dropbox.com/u/17046710/3.png[/IMG]