 The trial shall assess the accuracy of the Oxitone 1000 in measuring oxygen saturation, by comparing its measurement to reference devices: non-invasive SpO2 and pulse-rate values determined by a pulse oximeter. A total of approximately 40 subjects: 20 healthy and 20 COPD chronic obstructive pulmonary disease patients will be enrolled. These subjects will be enrolled at the medical center pulmonary department and will be recruited from the clinic patient base. The subjects will be represented by male and female adults who optimally cover a range of ethnic backgrounds skin pigmentation. All testing will be performed in singleton and in a blinded fashion. This study will be conducted with the approval of the medical center ethics committee. 