Fluke Biomedical 2MF Index - Manual (Page 78)

Index 2MF
Users Guide
11-2
Fluke Biomedical has equipped the Simulator to allow you the widest array of simulation,
with the capability for direct control of the following the Simulator functionality:
•
Bulk red light attenuation
•
Bulk infrared light attenuation
•
Peak-to-peak red pleth wave amplitude control
•
Peak-to-peak infrared pleth wave amplitude control
•
Shape of the pleth wave
•
Simultaneous attenuation of both red and infrared by selected percent
•
Generation of simulated ambient light
Note
See “Appendix E: Computer Control” for more information on the the
Simulator computer control command. Refer to “Appendix A: Printing &
Data Transfer”, for information on the RS232 port and how to set
communications parameters (baud rate and parity settings).
Mathematical Background
The Simulator assumes that any oximeter under test uses the “ratio of ratios” formula,
where a quantity “R” correlates with SpO2, the dc terms are fixed attenuations, and the
ac terms are peak-to-peak measures of additional attenuation due to the pleth wave (see
the next section for help interpreting the formulas). The “ratio of ratios” formula is:
R=redac/reddc
iredac/ireddc
math_bg_formula.eps
Oximeters perceive the Simulator to be using a variant of the above formula, which
causes the dc terms to “drop out”.
Note
In the following formula, “REDUUT” means RED-light, Unit Under Test
and “IREDUUT” is for InfraRed light, Unit Under Test.