Optical methods and devices have been used for a variety of biomedical applications for about twenty years for chemical analysis in colorimetry and spectrophotometry. More recently instruments for direct chemical analysis in tissues have been developed, and at the beginning of the twentieth century, instruments based on the use of visible light began to be used. Through a lot of research, it has been found that the near infrared part of the electromagnetic spectrum has the ability to penetrate deeper into biological tissues compared to visible light. Infrared imaging allows achieving safe and noninvasive monitoring of important variables in a variety of clinical applications.