Displacement measurements, human body

An attractive feature of fiber sensors is the possibility of performing in vivo tests and monitoring. Numerous fiber-optic sensors have already been described that measure physical parameters of the human body [41]. Pressure, temperature, physiological flow, strain, motion, displacement, or flow velocity can be monitored by optical methods such as variable reflection, laser Doppler velocimetry, optical holography, or diffraction. In this section the application of optosensing methods to the determination of molecular species encountered in clinical and biomedical analysis is described. 

Vibration can cause problems to the human body, machines and structures, as well as producing high noise levels. It is commonly measured using an accelerometer which can indicate a value in terms of acceleration, velocity or displacement. There are many types of accelerometer and associated instrumentation available which can give an analogue or digital readout or can be fed into a computerised analysis system. As with sotmd, the vibration component would be measured at particular frequencies or over a band of frequencies. 

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