Has anyone found a reliable floor mat alarm system?

I woke up this morning at 1:20am to find my 90-yr-old Mom standing in my bedroom (which is down the hall from hers) thankfully using her walker. She told me she was ready to go back to bed now but did not know where it was. Mom has lived in her house for 45 years!

I asked her where she had been and she replied, "Just checking things out." I noticed that interior doors that I had closed before going to bed had been opened. Thank goodness she did not activate the burglar alarm by opening an exterior door!

As I walked her back to her bedroom, she commented on pictures hanging on the walls in the hall saying "these would look great in my house!" When I told her she WAS in her house, she replied that she was not.

I am wanting to purchase an alarm mat that, when weight is placed on it, transmits an alarm signal to a pager that will be placed in my room.

None seem to get consistently good reviews and most seem expensive, although I really don't know what I should actually expect to pay to get a reliable one.

Has anyone purchased such a mat with pager that really worked and was reliable? If so, would you please share the brand and model? If I am ever going to sleep again, this mat is a necessity!

Thanks!