Explorative Study on a New Device' Ability to Register Hydration Change in Elderly Subjects During Rehabilitation.

Test the ability of continuous measurements from a new sensor patch to set the hydration state in subjects who are malnourished/dehydrated or overhydrated or otherwise not optimally hydrated. Specifically, clinical examination, blood pressure, blood tests, and weight change at the admission and at the discharge will be used to establish the true hydration status of the subjects.