Abstract
Near infrared (NIR) light (700 ~ 900 nm) possesses the capability of penetrating living tissues several centimeters due to the low absorbance of tissue intrinsic chromophores such as oxy- and deoxy-hemoglobin (the main absorber of visible light), melanin, water, and lipid (the principal absorber of infrared light). Featured with the deeper tissue penetration as well as nonionizing and nonradioactive, NIR light attracts extensive attentions on the development of noninvasive techniques for in vivo real time monitoring/tracing of biological signals in living tissues. Hitherto, NIR techniques have permeated to almost all aspects of health care, such as diagnosing disease (Nahum, Skippen, Gagnon, Macnab, & Skarsgard, 2006), designing the targeted molecular or drug carrier (Hsu et al., 2006), monitoring the response to therapeutic treatment (Tachtsidis et al., 2007), evaluating the rehabilitation, and so on. With the rapid development of various NIR techniques and more cooperation with clinic studies, more potential applications in health care will be exploited in the near future.
Key Terms in this Chapter
Fluorescence Probe: A specific agent that emits fluorescence with longer wavelength when excited by the light within its absorption range.
Near Infrared: Electromagnetic wave whose wavelength ranges from 700 nm to 900 nm. These lights have higher penetration depth in living tissue due to low absorption coefficient to hemoglobin in blood.
In Vivo Measurement: Measurements are performed on the body of living subject (human or animal) without taking the sample out of the living subject.
Pharmacokinetics: A study for the dynamic change of drug concentration in blood. This parameter can help researchers and clinicians to understand the properties of the drug.
Drug Distribution: A different amount of drugs will be accumulated in different organs or tissues when administrated in the living subjects.
Protein Drug: A type of drugs made of protein. These drugs usually have large molecular weight with protein characteristics.