There are home alone aged people,especially grandmother. They will be alone in house and rest of them have gone for the work, this is the situation for one to analyse here. Say Suppose if she is not feeling well, cannot shout and walk for a long distance.
There is a product available in called Medical Alarm which is a kind of alarm, they can press, if they are in neeed of any help. just by pressing this. they can give a notification to the concerned members. The concerned members will be linked so as to get help. By visiting the above link one can get a clear view about the product.