The project aims at the development of minimally invasive procedures for clinical analysis, which can be prepared by the patients themselves at home and sent by ordinary mail, with the subsequent improvements in the quality of life of patients with chronic or reduced mobility, helping to reduce their number of visits to the health center. In particular, the project will focus on two populations. On the one hand, people with metallic prostheses that require periodic controls to ensure their correct functioning. Bearing in mind that many of these patients show an advanced age, and the great extent and low population density of the Communities involved, this objective is very important from the social point of view. The other group selected is Wilson's disease patients, a rare disease, easy to treat but difficult to diagnose, that can be lethal without proper treatment. To achieve these goals, we aim at implementing the use of dried blood spots (DBS), a kind of sample obtained after puncturing the finger and applying a few drops of blood on clinical filter papers, as well as developing novel methods for their elemental and isotopic analysis. For these purposes, the teams of scientists selected at both sides of the Pyrenees have both fully complementary instrumentation and experience.