Nellcor OxiMax N 5500, Руководство по обслуживанию

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System Processing Description
N5500 Service Manual 89
Technical
Information, N5500
B. For data collection and the data analysis, Bland-Altman Plot is used.
C. On the systolic, diastolic, and MAP, the Deltas of all measurements shall be met
under +/- 5mmHg of mean difference (MD), and +/- 8mmHg of standard deviation
(SD).
(Delta = Intra-arterial or Auscultatory – Automated sphygmomanometer)
20
-20
-15
-10
-5
0
5
10
15
200 180 160 140 120 100
SYSTOLIC PRESSURE
Mean difference(MD): 0 mmHg
Standard deviation(SD): 6 mmHg
mean + 2 SD
mean
mean - 2 SD
Average of test and reference methods (mmHg)
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(EXAMPLE) Agreement between test and reference methods for systolic pressure. Hypothetical data
10.5 SpO
2
Processing
Pulse oximetry works by applying a sensor to a pulsating arteriolar vascular bed. The
sensor contains a dual light source and photodetector. Bone, tissue, pigmentation, and
venous vessels normally absorb a constant amount of light over time. The arteriolar bed
normally pulsates and absorbs variable amounts of light during systole and diastole, as
blood volume increases and decreases. The ratio of light absorbed at systole and
diastole is translated into an oxygen saturation measurement (SpO
2)
. Because a
measurement of SpO
2
is dependent upon light from the sensor, excessive ambient light
can interfere with this measurement.
Pulse oximetry is based on two principles: that oxyhemoglobin and deoxyhemoglobin
differ in their absorption of red and infrared light (spectrophotometry), and that the
volume of arterial blood in tissue (and hence, light absorption by that blood) changes
during the pulse (plethysmography). The monitor determines SpO
2
by passing red and