几乎每一个电磁波段都可以用于医学诊断或作为治疗疾病的物理手段。例如常用来做胸部或腹部透视的X光,就是一种波长为几十埃的电磁波(1埃=10~(-10)米)。治疗癌症的主要手段之———放射疗法中常采用波长比X光更短的γ射线。经常作为消毒源使用的紫外线则是波长比X光为长的一种电磁波。红外线也是一种电磁波,它的波长比上述三种电磁波都长。红外线在医学上的应用早年只是利用红外线灯泡进行理疗,随着最近二十年来红外技术的发展,实际上已陆续出现了许多种新的医学应用。红外线的波长范围很广,从0.75微米一直伸展到1000微米(1微米=10~(-6) Almost every electromagnetic band can be used for medical diagnosis or as a physical means of treating diseases. For example, X-rays commonly used for chest or abdominal perspective are electromagnetic waves with a wavelength of several tens of angstroms (1 angstrom=10 to (-10) meters). The main means of treating cancer—radiotherapy often uses gamma rays with shorter wavelengths than X-rays. Ultraviolet light, which is often used as a source of disinfection, is an electromagnetic wave having a longer wavelength than X-rays. Infrared is also an electromagnetic wave whose wavelength is longer than the above three types of electromagnetic waves. The application of infrared in medicine was only using infrared light bulbs for physical therapy in the early years. With the development of infrared technology in the last two decades, many new medical applications have appeared in succession. Infrared wavelength range is very wide, extending from 0.75 microns to 1000 microns (1 micron = 10 ~ (-6)