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Human NIBP Nano
Owner’s Guide
venous compartments is facilitated by the enlarged capillary diameters
at the arterial pressures their walls sustain. It is also facilitated by relaxed
arterioles (including the arterio-venous anastomoses). Relaxed arteries
are present in the absence of sympathetic nervous tone, vasopressors, or
cold. Relaxed arterioles and a normal colored finger tip are seen frequently
during normal sleep.
Gravenstein [1985] reported a substantial capillary oxygen pressure
remaining in the finger tip distal of a finger cuff from 49 to 58 mmHg
(compared to 80 mmHg normally) and pulse oximeter saturations of about
93%, albeit with much variability.
With all vessels in the distal finger tip at arterial pressure, one would
expect an increasing diameter of that part of the finger, since at high
capillary pressure increased leakage of liquid through capillary pores is
expected to fill the interstitial space, however this has not been observed.
A slight decrease of finger diameter under the cuff is usually observed
aft er a prolonged period of blood pressure measurement. This decrease
in finger diameter can be attributed to interstitial liquid being pressed
out into the capillaries and the lymphatic system, to return to the veins.
Also, red blood cells trapped in the micro-circulation by the applied cuff
pressure have been observed to wash out in a period of several minutes.
Although this evidence does not prove that damage to the finger
monitored with Human NIBP Nano cannot occur, no problems have been
apparent since the introduction of finger blood pressure measurement in
the early 1980s. In order to avoid long lasting congestion or discomfort,
the Human NIBP Nano is equipped with a two-finger switching mode
that can automatically switch between two fingers in alternation. This is
recommended for recordings greater than 1 hour in duration.
Cardiac output and stroke volume
The Human NIBP Nano is compatible with the Non-Invasive Cardiac
Output (NICO) Extension for LabChart. This free add-on, available from
within LabChart’s feature manager, allows for estimates of Cardiac Output,
Stroke Volume and Total Peripheral Resistance to be calculated in a
LabChart channel. Details on how to use this extension and the algorithm
it is based on can be found in the the LabChart Help menu aft er installing
the extension.
Measurement accuracy
Human NIBP Nano enables the measurement of continuous arterial
blood pressure in the finger. It is important to realize that the finger
arterial blood pressure may diff er from the blood pressure measured
Содержание Human NIBP Nano
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