Dräger Medical JM-103, Руководство по эксплуатации

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DRAFT 20 June 2005
Page 2 - 2 Jaundice Meter (Model JM-103) User Manual (usr070)
Explanation of the Test
Measuring Principle
The Jaundice Meter determines the yellowness of an infant’s
subcutaneous tissue by measuring the difference in the optical densities
for light in the blue (450 nm) and green (550 nm) wavelength regions.
The measuring probe has two optical paths. This method allows for a
more precise measurement of yellowness in an infant’s subcutaneous
tissue by minimizing the influences of the melanin pigment and the skin
maturity.
When the measuring probe is pressed against the forehead or sternum of
the infant, the built-in xenon lamp flashes. The light from the xenon
lamp passes through the glass fiber and illuminates the skin. The light
scatters and is absorbed in the skin and subcutaneous tissue repeatedly,
and then finally returns to the sensor side of the glass fiber. Of the light
that returns, the part scattered from the shallow areas of the
subcutaneous tissue passes through the inner core, or short-optical path,
of the fiber. The part scattered from the deep areas of the subcutaneous
tissue passes through the outer core, or long-optical path, and then
reaches its corresponding photodiode.