System Start Up Sequence; Alternating Head Cells Modification - Getinge Arjohuntleigh NIMBUS II Service Manual

Introduction
It is pneumatically connected in parallel to the mattress cells and when it is not occluded it channels the
air supply away from the cells. Occlusion of the Auto-Matt sensor is by patient weight and position. In
this manner it allows internal mattress air pressures to be compensated to that required to support the
patient.
With no patient on the mattress the Auto-Matt sensor is not occluded and pressure in the mattress is
governed by the pressure control shown in Figure 2 . This is in turn set to a pressure range which can
be slightly adjusted to change mattress pressures for patient comfort.
With a patient on the mattress, pressure is exerted onto the cells and this can partially or totally occlude
the Auto-Matt sensor. This results in more air being supplied to the cells increasing their internal
pressure until full patient support is achieved. Should the patient change to a position which necessitates
a lower pressure, air is released via the Auto-Matt sensor through the pressure control valve until the
correct lower pressure is achieved in the cells.

System Start Up Sequence

After the pump is switched on the start up sequence is as follows:
• All display indicators illuminate for a few seconds.
• Low Pressure and Wait indicators remain illuminated while the mattress inflates (approx 20 Min). All
the other indicators go out.
• The pump runs one compressor until the rotor turns to the cross over position (within 5 Min).
• The rotor then depresses the microswitch which stops the rotor and activates the second
compressor.
• Both compressors run for 20 minutes or when the mattress reaches the minimum pressure setting.
• When the minimum pressure setting is reached the Low Pressure and Wait indicators go out.
• The pump cuts down to one compressor and the rotor starts to rotate.
• In Dynamic Mode the compressors will alternate every 4 hours.
• In Static Mode the Coils (4 off) will alternate every 4 hours (one at a time). The compressors
alternate depending on which coil is working (there are two coils in each compressor).

Alternating Head Cells Modification

The Nimbus and DFS beds are normally supplied with the top three (head) cells configured so that they
are inflated to a specific pressure. Although the pressure in the head cells normally remains constant,
the pressure in the rest of the cells slowly alternates.
The Alternating Head Cells Modification converts the static head cells into alternating cells. The
modification can be applied in two configurations that follow:
Configuration 1 converts all three head cells from static pressure to alternating pressure.
Configuration 2 converts the second and third cells from static pressure to alternating pressure. The
top head cell remains as a static pressure cell.
Chap 1
Page 4 SER0001
Nimbus/DFS Service Manual
Issue 2
April 2010