Doc suggested cameras to protect my Mom when we leave her alone for short periods. She mentioned Ring. Has anyone installed them or others?

I have Blink camera's. I love them.

We have a Camera at my mom's its a great idea. Ring is good we have Reolink but I don't recommed it Ring is better

When I was working and leaving my mother with MCI alone a couple of days a week, I used the security system and door camera to monitor my mother. At that point, her MCI mainly impacted her memory and she was coping well with some memory aids in checklists and labels. I had the security system monitoring her bedroom door, the bathroom door, and the external doors. I had webcams in the common room (kitchen, living and dining rooms), hallway, and the external doors. My nephew lived next door and his wife was usually home during the day and we have good neighbors.

When the doors were opened and closed, I got a text. If Mom pushed her panic/help button, I would have been notified in addition to the EMTs called. Ditto for the fire alarems. My plan was to call my niece-in-law to check on my mother if she didn't start moving around in the morning (I left before she got up) or if she went on her walk and didn't return on time. Never had any problems, but the monitors and cameras made me feel better and I would have been able to call for help if it had been needed.

We lived on a one-lane road in the country with limited vehicle traffic and everyone knew my mother and knew she walked the road at mid-day. Mom's MCI never impacted her decision-making the way vascular dementia impacted my father. Mom was always able to make good decisions assuming she could remember all the facts. At this point, she was always orientated to time and place too. I needed to call her to remind her to get her lunch out of the fridge but didn't need to concern myself she might try to wash the dishes with the drain cleaner.

When Mom became wheelchair/bed bound, I placed a camera with two-way voice in her bedroom so I could check on her without disturbing her or keep an eye on her when I was in the yard or making a very short run to pick up something. It worked for us.

Yes, you say Mom has a Dementia. Dementia is unpredictable. There is no rhyme or reason to it. I really can't see a Dr. Suggesting a Ring if Mom is passed the first stage.

Would your doctor suggest a camera to be put in place if you left a 3, 4, 6 year old home for a short period of time?
I have to wonder what good a camera would do if you saw mom in trouble? How long would it take you to get to her if she fell and could not get up.
If you saw her leave the house dressed in light weight pants and a blouse and slippers and the temp is 10 degrees F? How far could se get before you got home?
What if she put a pan of soup on and ...
You get the idea. It is not safe to leave anyone with dementia alone even for a short period of time.

I am sure EVERYONE has done this at least 1 time. While it is understandable it is not a good idea.
I think that putting cameras in will give you a false sense of security and "permission" to leave her.

I have the Blink cameras that I originally purchased when my husband was completely bedridden in our living room and I wanted to be able to check on him when I had to be out and about for any reason. Mine are the older models that you can only hear the person when you're checking on them, but they now come with 2 way talk which is even better. They're easy to set up, not very expensive, and you access them through your phone. They're a great peace of mind.

I've installed both. I had a SimpliSafe security system and a ring camera on the entrance door. Both were easily installed (at least for me, I am a techie).

Both are connected to your home internet and provide a web interface to manage them, both allow you to view your cameras remotely. Both require you to change the default passwords if you want a "secure" system. I purchased the security system first, and I like I could set up text alerts to my phone when certain doors were opened or closed. Ring would notify my phone whenever someone came to the door too. The last time I looked, Ring had a good security system but didn't allow you to set up as many monitors on the different devices. Ring _allows_ you to become a member of a community group that shares the output from their cameras.