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This matching may be assessed in the lung as a whole, or in individual or in sub-groups of gas-exchanging units in the lung. On the other side Ventilation-perfusion mismatch is the term used when the ventilation and the perfusion of a gas exchanging unit are not matched. The actual values in the lung vary depending on the position within the lung.
In a condition such as pulmonary embolism, the pulmonary blood flow is affected, thus the ventilation of the lung is adequate, however there is a perfusion defect.Gas exchange thus becomes highly inefficient leading to hypoxemia, as measured by arterial oxygenation.
Furthermore, adequate achievement of ventilation and perfusion matching is essential as it ensures the continuous supply of oxygen and withdrawal of waste products from the body. Thus, strict regulation of ventilation and perfusion is needed for efficient gas exchange .
A ventilation/perfusion lung scan, also called a V/Q lung scan, or ventilation/perfusion scintigraphy, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs, [1] [2] in order to determine the ventilation/perfusion ratio.
Vector quantization (VQ) is a classical quantization technique from signal processing that allows the modeling of probability density functions by the distribution of prototype vectors. Developed in the early 1980s by Robert M. Gray , it was originally used for data compression .
Different matching methods, such as velocity matching and position matching, are designed to improve the speed and accuracy of the alignment. Different factors will affect the accuracy of the transfer alignment, such as reference information delay, mounting error, sensor measurement error, lever-arm effect [2] and flexure of the carrier body.
Matching is a statistical technique that evaluates the effect of a treatment by comparing the treated and the non-treated units in an observational study or quasi- ...
The lattice of stable matchings is based on the following weaker structure, a partially ordered set whose elements are the stable matchings. Define a comparison operation on the stable matchings, where if and only if all doctors prefer matching to matching : either they have the same assigned hospital in both matchings, or they are assigned a better hospital in than they are in .