Although early identification and treatment of sepsis have had top priority among the working tasks of the international 'Surviving Sepsis Campaign' society (collaboration of the Society of Critical Care Medicine and the European Society of Intensive Care Medicine) for several years, which have led to improved survival over the last two decades, there is no objective validated diagnostic test to identify or to support the clinical diagnosis at an early stage. Analogous, there is no validated monitoring system available to guide and evaluate the effects of stabilizing measurements in sepsis, or other critical disease, at the microcirculatory level. And thus, there is an enormous knowledge gap regarding dynamic changes at the microcirculatory level during sepsis and other critical disease.