Upper limb arterial disease is a rare condition compared to lower limb arterial disease. In the lower limb, chronic limb ischemia (CLI) is characterized by an intractable pain or an ulceration present for at least 2 weeks. Guidelines recommend to use Transcutaneous Oxygen pressure (TcPO2) measurement when a CLI is suspected to establish diagnostic with a threshold of 30 mmHg when ankle and toe systolic pressure are not available. In the upper limb, there is no guideline to define CLI. When there is a wound preventing finger pressure measurement, TcPO2 is theoretically indicated. However, there is neither standardized site to measure nor threshold value of TcPO2. The investigators hypothesized that normal TcPO2 may be different in the upper limb and that threshold value for CLI may also be different compared to lower limb. The investigators planned a study with two parts: 1. Prospective study of normal TcPO2 value in healthy volunteers 2. Retrospective analysis of patients with upper limb arterial disease to approach the TcPO2 threshold of CLI allowing healing in upper limb