Is Telehealth good option for my elderly parents

My parents are in their late Eighties and live at home. My sister worries about them a lot as both she and I don't live nearby and their health is becoming increasingly fragile (my mum has the beginnings of Alzheimer’s). I believe you can get some kind of alarm systems set up to alert us if they have a fall or an accident through using telehealth. My sister and I would love to know more, particularly if there are any users out there who could give recommendations about the best equipment to buy and where from, what great new gadgets are available and where else we could get advice.