Population Research of Sublingual Microcirculation Data of Healthy Volunteers

Inclusion Criteria: * Healthy volunteers aged from 20 to 79 years old * BMI ranged from 18.5 to 27 kg/m2 Exclusion Criteria: * Systolic blood pressure \> 140 mm Hg, diastolic blood pressure \> 95 mm Hg, or systolic blood pressure \< 90 mm Hg at enrollment * Body temperature \> 37.5 ℃ or \< 35.5 ℃ at enrollment * had been diagnose with any one of the following diseases * hypertension * diabetes mellitus * peripheral arterial occlusive disease * coronary arterial disease * liver cirrhosis * chronic kidney disease * stroke * anemia * asthma * chronic bronchitis * any metabolic diseases * any hematologic disease * uncured cancer * chronic uncontrolled infection * other disease may limit daily activities * non-native speakers