12
SECTION 3.0
A.T.S. 2000 TOURNIQUET SYSTEM
MAINTENANCE
3.1 GENERAL MAINTENANCE INFORMATION
While the
A.T.S.
2000 Tourniquet has been designed and
manufactured to high industry standards, it is recommend-
ed that periodic inspection and calibration be performed to
ensure continual safe and effective operation. This section
contains information to assist in that effort as well as serve
as a guide to expediting unscheduled maintenance.
This unit is organized into easily accessible modular as-
semblies for ease of service. The major subassemblies of
the unit are shown in Fig. 3 through 10.
3.2 GENERAL THEORY OF OPERATION
Refer to Block Diagram (Fig. 3).
The
A.T.S.
2000 Tourniquet is a microprocessor controlled
automatic tourniquet. The microprocessor takes inputs from
various switches, the A/D converter, and memory, then
uses this information to generate commands to the outputs
(valves, pump, displays, alarm circuitry) to regulate cuff
pressure. The pump and the eight valves control the infla-
tion, deflation, and regulation of the tourniquet cuff(s).
The main and second cuffs are connected to the pump via
a reservoir and manifold. There are eight valves mounted to
the manifold to control the inflation, regulation, and defla-
tion, four valves for each cuff. The cuff valves are further
divided as slow and fast inflate, as well as slow and fast
deflate valves. When a cuff is inflating, the fast inflate valve
opens to pressurize the cuff quickly. When the cuff is deflat-
ing, the fast deflate valve opens to remove pressure quickly.
The slow inflate and slow deflate valves are used to regu-
late the pressure during cuff regulation. Please note that
block diagram Fig. 3 shows all valves in their off (no power)
condition. In the event of a power failure or if the unit enters
a failure mode, power to the valves will be removed and all
of the valves will close which will prevent internal leaks.
The three pressure transducers, main cuff, second cuff, and
reservoir, are connected to the A/D converter via high preci-
sion amplification circuitry. The digitized pressure signals
are used by the microprocessor to regulate the pressure in
the cuff(s) as well as in the reservoir. The condition of the
pump, transducers reference, +15 volts, and safety monitor
voltages are periodically checked for proper voltage levels.
The battery condition is checked during power up for proper
connection, i.e., broken wire or blown battery fuse. The unit
can alarm when the battery voltage becomes low during a
loss of AC (~) power or during patient transport.
The Windowing Watch Dog Circuit (Safety Processor) is a
hardware circuit that monitors the timing signal generated
by the microprocessor as well as valve states and system
modes. Should any abnormality exist, indicating a problem
with either the microprocessor, software, or valves, the
safety processor will remove power to all eight valves. This
means the valves will all close, flag the microprocessor of
the error and turn the alarm light and speaker on. If the mi-
croprocessor is able, a message will be displayed indicating
the failure.
3.3 ACCESS TO PARTS
CAUTION:
BE SURE THAT THE UNIT IS SET TO STAND-
BY AND THE POWER PLUG IS UNPLUGGED BEFORE
DISASSEMBLY.
CAUTION:
MANY OF THE PARTS ON THE CPU AND
POWER SUPPLY PRINTED BOARDS ARE STATIC SEN-
SITIVE. TAKE APPROPRIATE PRECAUTIONS WHEN
SERVICING THESE BOARDS.
To gain access to all internal parts, first remove the four
rubber feet from the bottom of the unit. Remove the I.V. pole
clamp knob, and the 2 screws from the top back of the unit,
and then slide the back cover away from the front.
See Fig.
4–7.
To access the power supply and CPU boards, remove the
3 screws from the bottom of the chassis, just behind the
battery compartment‚ along with the 2 screws from the front
top chassis. By removing these 5 screws, the chassis will
be divided into two halves for clear and easy access. See
Fig. 8–10.
3.4 PERIODIC MAINTENANCE
Test and inspect as per this section at least every 6 months.
3.4.1 CLEANING
The exterior of the unit may be cleaned with a cloth that
has been dampened (not dripping) with a mild detergent.
The interior of the unit may be vacuumed or blown out as
required. The exterior of the cuff hoses may be cleaned
using a mild detergent solution or with alcohol. The interior
of the cuff hoses should not be cleaned. Tourniquet cuffs
should be cleaned in accordance with their cuff package
insert instructions.
3.4.2 INSPECTION
The unit should be inspected at regular intervals. It is
recommended that a visual inspection be performed by
a qualified technician at least every 6 months. Inspection
points are:
•
Obvious internal or external damage;
•
Condition of the power cord;
•
Condition of hoses (both internal and external cuff con-
nection hoses);
•
Accumulation of dust or dirt within the unit;
•
Mating integrity of internal connectors;
•
Integrity of battery fuse mounted on the CPU printed
circuit board;
•
Security of the EPROM (U15) and safety processor
(U10). See Fig. 11 for location;
•
Integrity of the pump filters;
•
Tightness of the pump mount.
3.4.3 FUNCTIONAL AND CALIBRATION CHECKS
It is recommended that the functional and calibration
checks described in Section 2.2 be performed at least once
a quarter.
Summary of Contents for A.T.S. 2000
Page 1: ...Operator Service Manual A T S 2000 TOURNIQUET SYSTEM REF 60 2000 101 00...
Page 25: ...23 3 Block Diagram...
Page 28: ...26 11 CPU Board...
Page 29: ...27 12 Power Supply Board...
