23
Chapter 2
Setting Up
An example of what you should see is shown in Figure 2–3. Th
is fi gure also
shows a typical waveform from the LDF output. You can use a
Low pass
fi lter
setting to remove any unwanted noise. You should not use the
AC coupled
feature as this will result in an incorrect measurement of blood perfusion
units.
BSC Output Calibration
Calibrating the BSC channel is a similar process to that for the LDF output,
but with diff erent values required. As the BSC output represents the relative
strength of the returned signal, it is a voltage that represents the percentage of
backscattered light. A 100% backscattered signal is represented by a voltage
of 5 V. Zero backscattering corresponds to 0 V. Th
is gives an output that
corresponds to 50 mV per % backscattering.
Removing the Probes
To remove a probe from the instrument, gently pull the outside of the probe
connector (the knurled sleeving). Th
is will disengage the locking mechanism
and the connector should just pull out. Do not attempt to force the connector.
Figure 2–3
Amplifi er dialog once LDF
waveform conversion has
been applied
