Inclusion Criteria:  Men and women in the age range from 18 years to 85 years old. For subproject 1 and 3 the participants must be diagnosed with either rheumatoid arthritis or systemic lupus erythematosus. Must sign and date informed consent.  Exclusion Criteria:  Lacking ability to make or understand informed consent. Medical history with psychiatric or psychological conditions which the person in charge of the research estimates will affect the participants ability to participate in the study. Furthermore participants with severe mental illness will be excluded due to the fact that severe mental illness cause decreased heart rate variability. Pregnancy. Addict or prior addict defined as abuse of hash, opioids or other euphoriant drugs. Known atrial fibrillation or atrial flutter. Known chronic lung disease.