Reproducibility Procedure (optional) Each subject will be measured by each one of the three operators, three NBM system units, 3 times consecutively (without removal) on his right thumb and right index finger. The order of each measurement sequence will be randomized (thumb/index). There will be an intermission of 3 to 5 minutes between the 3 measurement sets taken on each participant. In case of a longer intermission, the subject will be measured again and the previous results will be excluded.