Method and apparatus for determining a duration of a medical condition

摘要

A system and method for determining a duration that a patient has been experiencing a medical condition compares characteristics of fluorescent emissions from a target tissue to expected characteristics. In a system and method embodying the invention, a target tissue is illuminated with excitation light, and fluorescent emissions generated by the target tissue in response to the excitation light are detected. Different characteristics of the fluorescent emissions, including the fluorescent emission intensity or the fluorescent lifetime may be determined. The determined characteristics of the detected fluorescent emissions are then compared to expected characteristics of the fluorescent emissions. The amount that the detected fluorescent characteristics deviate from the expected fluorescent characteristics is used to determine a duration that a patient has been experiencing a medical condition. In some instances, the backscattered portions of the excitation light may also be used to make the determination.