The monitoring would be done by a base station located within the persons house which would track each sensor, an example would be PIR sensors located around the building tracking simple movements. The system would initially be learning what the person does, for example my grandmother always gets up around 6am, come 7am I would like an alert to suggest she's not following her usual routine and I should check on her.

The local base station would report back into a central station which can perform the alerting, or alternatively the local base stations would have internet access via GPRS etc to perform the alerting.

This could be extended to wearable tech which again reports back into a local basestation, this would reduce the power usage needed of wearables and size as they can use simply wireless technology rather than IoT type tech which needs direct connectivity.