Life-supporting oxygen is supplied to all human tissues by hemoglobin, a carrier protein present in the bloodstream. When illuminated with near infrared light (NIR: 650-1000 nm), hemoglobin absorbs differently depending on whether it is bound to oxygen molecules (i.e., oxyhemoglobin, HbO), as in arterial blood, or is unbound to oxygen (i.e., deoxyhemoglobin ore reduced hemoglobin, HbR), as in venous blood. Since NIR light penetrate relatively deep (up to a few centimeters) into tissues such as skin, fat and muscle, the concentration of oxyhemoglobin and deoxyhemoglobin can me measured in-vivo with an optical techniques called near infrared spectroscopy (NIRS).

In our lab, we develop optical sensors and conduct studies to investigate relationships between tissue oxygenation, blood perfusion and/or blood flow and the specific function carried out by a specific tissue or organ. For instance, we study how exercise intensity affect skeletal muscle oxygenation in athletes, or how reduced blood flow in bedridden patients originate pressure ulcers, also called bed sores. Please contact us to learn more about our current activities and developments.