Inclusion Criteria:  Informed consent obtained, and letter of authority signed before any study related activities Are at least 18 years of age and have full legal capacity Healthy skin behind the ear  Exclusion Criteria:  Pregnant or breastfeeding Known allergic responses to the adhesives Treatment with corticosteroids, either as a cream in the area behind the ear or systemically (tablet or injection) within the last month Subject is unable or does not have the necessary assistance to properly operate the device system