I need suggestions for a device/alarm to let me know when my loved one gets up in the middle of the night.

I just got my mother
a motion detector activated voice recording from Amazon. It records in two volume levels and for up to two minutes. My mom was sleeping on the toilet. Sierra Tech motion activated voice recorder. It was around $25. I ended up buying two more. Now if some one can help me keep mom from sleeping in the toilet ...

So, you want to be alerted as soon as your LO gets out of bed? If you're not a deep sleeper maybe a baby monitor would be a good temporary help until you find a better permanent solution. Others with experience will post their suggestions.