Dynamic Mode - Getinge Arjohuntleigh NIMBUS II Service Manual

Introduction

Dynamic Mode

In dynamic mode the support surface beneath the patient is cycled every 10 minutes providing periods
of pressure relief for the whole body.
Figure 1 and Figure 2 show how the system operates in dynamic and static modes. Figure 2 shows the
pneumatic circuit in principle. A dual compressor system is used to provide a source of air supply. This
is fed to a high pressure switch, the Auto-Matt sensor and a rotary valve. The high pressure switch is
used to detect system over-pressures through blockages. The low pressure switch, which is located in
the pressure control assembly, is used to detect if the air pressure in the system falls below minimum.
The rotary valve channels the air supply as shown below:
C to outlet A with B at atmosphere (D)
C to outlet A and B
C to outlet B with A at atmosphere (D)
C to outlet A and B
This then allows cells A and B in the mattress to be inflated and deflated in a cycle period of ten minutes.
In the mattress there is a third section of cells labelled as C. These are fed through partial non-return
valves from cells A and B and are therefore never at zero pressure. These are positioned as shown in
Figure 1 to prevent the torso section from 'bottoming' during dynamic mode and when a patient is sitting
upright. Semi-dynamic pressure is also applied to the head cells (C) and the heel protector (above CPR
unit) for added patient comfort.
On Nimbus 3 and DFS 3, loop sheets, the heel cells have a special powered-down feature to facilitate
fast deflation and thereby improve pressure relief under the heels.
Chap 1
Page 2
Figure 1 - Mattress Cell Inflation Cycle
SER0001
Nimbus/DFS Service Manual
- A & C Cells Inflated
- All Cells Inflated (A, B & C)
- B & C Cells Inflated
- All Cells Inflated (A, B & C)
Issue 2
April 2010