Alarm device for PEG tube.

My father is 82 years old and has dementia.He recently had a PEG tube inserted.The problem is that he keeps pulling on it, and even though we put a bandage around the area, he eventually gets to it and we're afraid that he will pull it out.As it takes him some time to get through the coverings I think that if I were to put a type of motion sensor that will beep when he starts playing around with the bandages the aid can be alerted and distract him and stop him.Can anyone recommend something?Thank you for the help.