Search results
Results From The WOW.Com Content Network
Photoplethysmography of the thumb by off-axis digital holography. pulsatile waves on the back of a frog measured by off-axis holographic photoplethysmography Remote photoplethysmography can also be performed by digital holography , which is sensitive to the phase of light waves, and hence can reveal sub-micron out-of-plane motion.
The PPGV was found to be useful in detecting blood loss by observing the spectral features of the PPGV. [3] [4] [5] LF power, together with other features derived from the PPG waveform, was used to classify patients into different ranges of systemic vascular resistance, which may be used as an indicator of critical illness. [6]
The fourth Purkinje image (P4) is the reflection from the inner (posterior) surface of the lens. Unlike the others, P4 is an inverted image. Purkinje–Sanson images are named after Czech anatomist Jan Evangelista Purkyně (1787–1869) and after French physician Louis Joseph Sanson (1790–1841).
Vaginal photoplethysmography (VPG, VPP) is a technique using light to measure the amount of blood in the walls of the vagina. The device that is used is called a vaginal photometer . Use
Brewster's angle (also known as the polarization angle) is an angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection. When unpolarized light is incident at this angle, the light that is reflected from the surface is therefore perfectly polarized.
The books were a model of popular science exposition: although Newton's English is somewhat dated—he shows a fondness for lengthy sentences with much embedded qualifications—the book can still be easily understood by a modern reader. In contrast, few readers of Newton's time found the Principia accessible or even comprehensible. His formal ...
A single reflection off the backs of an array of raindrops produces a rainbow with an angular size that ranges from 40° to 42° with red on the outside and blue/violet on the inside. This is known as the primary bow. A fainter secondary bow is often visible some 10° outside the primary bow. It is due to two internal reflections within a drop.
Diffuse reflection is the reflection of light or other waves or particles from a surface such that a ray incident on the surface is scattered at many angles rather than at just one angle as in the case of specular reflection.