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Human NIBP Nano
Owner’s Guide
Systolic
While the Human NIBP Nano is measuring finger arterial blood pressure,
a slight pulsation in the cuff ed finger is felt which is synchronous with the
heart beat. At regular intervals an AutoCal is performed during which cuff
pressure is held at constant pressure levels and no pulsation can be felt for
two or more beats.
AutoCal frequency
In the first one or two minutes aft er the start of a finger blood pressure
measurement the Human NIBP Nano device has to deal with the emptying
of small microvessels from blood under the cuff . The absorption of the
light between light source and light detector usually decreases due to
this eff ect. This change in absorption has nothing to do with the unloaded
diameter of the finger artery and is compensated for by the system. Since
this eff ect is more pronounced immediately aft er starting a blood pressure
measurement, an AutoCal procedure is scheduled initially aft er every 10th
heart beat. Once the setpoint has become suff iciently stable this interval
is gradually increased to 70 beats, normally within 4 minutes.
Figure 2–16
Start-up procedure
applied at the start of a
measurement and after
fi nger cuff switching.
