AET Electronic Tourniquet Service Manual (SM001)

Contents 1.

Cautions ... 3

2.

General Maintenance ... 4

3.

Annual Test... 4

4.

Adjustments ... 10

5.

Setting Time and Date ... 10

6.

Clearing Records ... 11

7.

Screen Calibration ... 11

8.

Fault Finding ... 12

9.

Other Means of Fault Finding ... 14

10. Pneumatic Calibration ... 15 11. Mechanical Assembly ... 17 12. Setting slow Deflate/Inflate ... 18 13. Electrical Supply ... 21 14. Pneumatics ... 26 15. Updating Software ... 30 16. Electrical Safety Test ... 35 17. Spares & Test Equipment... 39

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1. Cautions This Medical Device may only be serviced with approved spares by trained Technicians using approved Tools and Equipment. All measuring equipment used to calibrate the device must be calibrated and traceable to National Standards

Anti Static precautions must be taken when handling the main PCB

This Device includes mains voltage and higher voltages on the PCB. Suitable precautions must be taken to avoid electrical shock. The device must be disconnected from the mains electrical supply except when the test can only be conducted with a mains connection, when adequate additional safety precautions must be taken.

This manual is to be used in conjunction with the Instructions For Use manual.

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2. General Maintenance -

Electrical Safety Test is to be carried out annually (every year) on the unit or more frequently as directed by the clinical establishment or as required due to the environment or damage, and after service or maintenance requiring case to be opened. The tests are to be conducted using equipment such as Seward Rigel 266. Tests are to be conducted based on the requirements of class Ib equipment.

-

Annually (Every Year) unit requires calibration to be checked and if necessary will need to be re-calibrated. (Refer to section 10 of this service manual for details on how to re- calibrate the unit).

-

Bi Annually (Every Two Years) the battery should be replaced as a preventative action

3. Annual Test The following tests will check to see if the unit meets the original factory settings and will indicate current & potential problems allowing service and preventative maintenance -

Turn on unit

-

Select twin channel

-

Select spanner icon

-

Check that the software issue is to the current mandatory issue

-

Press back icon to return to the twin channel screen

With a full battery or with the unit connected to the mains electrical supply -

With twin channel screen showing

-

Check that the screen responds appropriately to being touched if not calibrate as per section 7 of this manual

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-

Connect unit to mains supply ensure that mains icons shows

-

Ensure that you have a stop watch

-

Without connecting a cuff press one of the inflate symbols, air will vent from the reservoirs, allow this to vent until the alarm sounds to evacuate the reservoirs. Then press the deflate symbol twice and the air will stop venting. From the time that the deflate is operated to the time the pump stops running should be less than 2 minutes.

-

Inflation times greater than 2 minutes may indicate potential wear in the pumps seals or leaking non-return valve

Cuff Pressure test This test is to confirm whether the cuffs are achieving the required pressure set on the unit With a full battery or with the unit connected to the mains electrical supply -

Ensure unit is switched on

-

Select a channel (Blue or Black)

-

Take Test Hose 1 ANA 0066

-

Plug the appropriate end of the test hose into the selected channel on the unit

-

Plug the other end of the test hose into a cuff which has been wrapped around a ‘dummy arm’

-

Into the tee part of the test hose 1 plug the pressure tester

-

Turn on the pressure tester and select cmHg

-

Select a pressure on the unit of 300mmHg

-

Press the inflate button

-

Compare the pressure reading on the unit to the one on the Pressure tester

-

If the pressure matches to within 28.8 – 31.2 cmHg on the pressure tester then that channel is working correctly

-

Increase inflation to 600 and check if the pressure matches to within 57.6 – 62.4 cmHg on the pressure tester

-

Repeat the test on the other channel

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Slow Deflate This test will check whether or not the slow deflate is still set correctly -

Ensure the unit is switched on

-

Select a channel (Blue or Black)

-

Plug test cuff ANA 0069 into the selected channel

-

Inflate the cuff to 300 mmHg

-

When pressing the slow deflate

-

when the pressure reads to 100mmHg stop timing

-

The result should be within 45 –60 seconds

-

Repeat the same test for the other channel

start timing the deflation

NOTE: Time to deflate varies depending on how tight the cuff is wound Low Pressure & Pump Alarm This test will check whether the low pressure & pump alarm is working correctly. The alarm will sound if the unit cannot pressurise the cuff within a specified time:

-

Ensure the unit is switched on

-

Select a channel but do not connect to cuff

-

Wait until the reservoir has pressurised and the pump has switched off

-

Select pressure to 300mmHg

-

Press inflate

-

The air will vent through the cuff connection

-

This will cause the alarm to sound at 10 seconds

-

Press fast deflate

-

Repeat the above procedure for the other channel but do not press deflate until the spanner flashes this alarm indicates excessive pump operation and must occur between 5 minute & 5½ minutes

-

Once the icon is flashing deflate the cuff

-

Press the maintenance icon

-

Once the maintenance screen has appeared you will see the valve warning icon

-

To clear this press the

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which is adjacent to the warning icon.

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Cuff removed auto deflate. This test is to check the unit will turn off if a cuff is removed without deflating, to save batteries. -

Switch unit on and fit a cuff to a channel

-

Inflate the channel to 300mmHg

-

Without deflating the cuff remove it from the unit. Air will vent out from

the front. - After 10 seconds the pressure alarm will sound. - After a further 20 seconds the unit should turn itself off and the alarm will stop. - Plug the cuff back in, inflate and check normal operation.

Valve Activation Warning This test is to check whether the warning about the solenoid valves activating to often is working correctly

-

Ensure unit is switched on

-

Select channel

-

Connect Test hose 1 to selected channel, replacing pressure gauge with the needle valve & ensure it is closed

-

Select pressure to 300mmHg

-

Inflate cuff

-

While the unit is pressurised, open the needle valve slowly until a small leak has been created, this will cause the valve to activate and de-activate in quick succession and cause the maintenance icon to flash

-

Once the icon is flashing deflate the cuff

-

Press the maintenance icon

-

Once the maintenance screen has appeared you will see the valve warning icon

-

To clear this press the

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which is adjacent to the warning icon.

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Timer This test will check to see if the timer function is working correctly -

Ensure unit is switched on

-

Select channel

-

Connect cuff to selected channel

-

Inflate cuff to a set pressure

-

Check that the timer is running

-

Deflate the cuff

-

Allow screen to time out

-

When cuff is deflated the inflation time will be retained

-

Make sure the screen changes to indicate it has finished

-

Re inflate the cuff ensuring timer resets to zero

-

Deflate the cuff

-

Press the timer icon

this will reset the timer

Mains Indicator This is to confirm that the mains disconnection icon is working correctly

-

With mains connected ensure mains icon is displayed

-

Turn off mains and check that the mains disconnection icon

ap-

pears within one minute

Lock Function This is to ensure that the screen lock function is working correctly

-

Press the lock icon on the screen,

check on the screen that this

changes to this -

Press inflate & pressure adjustments, an alarm tone will be heard but the unit will not respond

-

Press the lock icon

again on the screen and the icon will

change to -

Check screen now responds

-

Repeat the locking test with the icon on the green bar along the bottom of the screen. This button will lock the screen but will not unlock. This has to be done with the

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icon.

Document No. SM001

Tourniquet service check list 

Open case and check state of hoses and wiring



Check battery and replace if needed.



Check charge voltage to battery is correct.



Check all internal screws are tight.



Check and update software.



Change volume, brightness and contrast to an acceptable level to make sure they will adjust.



Check slow deflate time.



Check low pressure and pump alarms.



Check pump on duration.



Check leak alarm.



Check valve activation warning.



Check pressure switches off after 30 seconds if cuff is removed from outlet.



Check timer.



Check mains indicator.



Check lock function.



Calibrate pressure.



Check cuff pressure is correct.



Calibrate screen.



Check time and date are correct.



Perform electrical safety test.

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4. Adjustments To adjust brightness contrast or volumes press the spanner symbol which will display.

-

,

Ensure that Brightness and Contrast are set to a value suitable to the lighting level in the area of use. Ensure volume level is set to an acceptable level

5. Setting Time and Date Time and date will need to be reset if power to the main PCB board is disconnected. 1.

Go into maintenance screen by pressing the spanner icon

2.

Press the date/time icon 31 /

3.

Enter the password 3478

4.

The time and date will then appear at the top left of the screen and

,

the number box will appear at the right of the screen

5.

To alter the time press the time symbol

, then alter the time by

pressing the number box, (note for single digits i.e. 3, add a zero at the front)

6.

To alter the date press the

31 , then alter the date by pressing the

number box (note for single digits i.e. 3 add the zero at the front)

7.

Once complete press the

icon situated at the bottom right of the

screen.

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6. Clearing Records To clear the records: 1.

Press the spanner icon

2.

Then press the clear icon

3.

Enter the password 3478,

4.

Press the clear icon

5.

Once complete press the back icon run screen

again, this will then clear the records, which will then return to the

7. Screen Calibration The screen is calibrated during manufacture to ensure that the processor knows where the operator’s finger touches the screen. If the sensitive area and the associated icon do not align then calibrate as below -

Press the maintenance symbol

-

Press the screen calibration symbol

-

Enter password 3478 & press

-

Viewing the screen from directly in front touch the small square with the tip of your finger

-

Touch the second square

-

During a count down of 5 to 1 you may test the settings by touch-

LCD

ing the screen. The unit will respond by placing a square at the same spot. The unit will then display the enter symbol

and a

countdown of 5 –1. To accept the new setting the enter symbol must be pressed. Failure to press

will revert to the previous

settings

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8. Fault Finding If the

maintenance symbol is flashing select the maintenance page by

pressing the maintenance symbol. The reason for a maintenance warning will be displayed adjacent to the

symbol

The table below shows the faults, which may occur on the Unit. The table includes the icon, which may appear, the description of the icon and how to resolve the problems.

Icon

mmHg

Fault

Cause

- Calibration required

- Excessive valve action

- Excessive pumping

- Leak in system

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Resolving Fault

- Faulty Pressure sensor

- Unit to be re-calibrated - Electronics to be exchanged

- Crushed tube to PCB

- replace tube

- Leak in system after solenoid valves,

- Replace pneumatic tray

- Leak in external hose/cuff

- Replace cuff/hose

- Leak in system prior to solenoid valves or after if above symbol is also displayed

- Replace pneumatic tray

- Faulty pump

- Replace pump

- Leak after valves or in external hose or cuff

- Replace external hose/cuff - Replace pneumatic tray

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The maintenance warning can be cancelled by pressing the

symbol

which is on the maintenance page. If the error is calibration and unit has not been re-calibrated, then the warning will reappear after the unit is turned off and on.

Before starting maintenance note warnings and then clear them. Then Check unit with a test cuff, which is known to be leak free. A leak in the external hose or cuff will trigger a maintenance/alarm.

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9. Other Means of Fault Finding The table shows icons, which are present on the general screen. These may indicate the following faults Symptom

Fault

Potential Cause

Resolving Fault

- Blown fuse

-

- Check fuses in mains inlet socket and cable if mains connected

- Blown Fuse

- Battery faulty

- Check power supply PCB Fuse - Replace battery

Pump keeps starting but no obvious leak

- Leak through pump

- Faulty Non-return valve

- Replace non return valve

Pump tries but will not start

- Blown Fuse on power supply PCB

Over inflated Cuff

- Faulty transducer

+ While mains connected

+ When unit only works on mains

Unit will not reach 600mmHg

- Check fuse on board

- Crushed internal tube to transducer

- Hose has been crushed when front panel was screwed on

- Remove and refit front panel/electronics - Replace crushed hose

- Regulator setting

- Regulator is set Incorrectly

- Reset regulator (see section 7) - Replace crushed hose

- Crushed pipe from pump

- Regulator contaminated

- Replace regulator

NOTE: Mains indicator when unplugging the unit from the mains will take approx 1 minute to respond, but when plugging unit into the mains the indicator responds straight away. NOTE: It is usual that the unit may become warm on the back when charging the battery. If after a few hours unit is still very warm suspect battery needs replacing 92451/5/200111

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10.

Pneumatic Calibration

The unit will need to be re-calibrated if there is an interruption of the power to the main board, for example:    

Replacing the battery Replacing the front panel Replacing the power supply board or fuse Disconnecting any internal power wires to the main board

When calibrating a unit it must be carried out at room temperature and the battery must be fully charged To Calibrate the unit :1.

Ensure that no hoses or cuffs are connected

2.

Go into the maintenance screen by pressing the ‘spanner’ icon,

3.

Press ‘mmHg’ icon

4.

The unit will then ask you to enter the code (Code is set at 3478)

5.

Then press ‘mmHg’ again

6.

You will then see the calibration screen appear.

(NOTE: when first entering this screen the unit must be allowed to exhaust the reservoirs. This will normally be when all the figures in the first line show zero or will not reduce further).

7.

Turn on the Digital pressure gauge and select mmHg scale and calibrate the zero point

8.

When reservoir is exhausted, connect the digitron pressure gauge to the tourniquet unit using the calibration test Hose 2, ensuring vent tap is open (close the tap to check the pressure still in the cylinders, then re open)

9.

Press the first zero on each of the number groups on the second line, when doing this the unit will bleep each time screen is pressed. The top line will now show zero. Close vent tap

10.

Then press the ‘

’ icon positioned at the bottom left of the screen,

this activates and deactivates the pump, 11.

Pump the system to 600 mmHg + 2mmHg (60cm Hg + 0.2cm Hg) using gauge as indication of pressure, not the screen.

12.

Take care not to inflate above 650mmHg (65cmHg)

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13.

If unit is over inflated reduce the pressure using the vent tap on the test hose

14.

Then press the 3rd line of figures reading 600mmHg.

15.

Once complete press the arrow icon

positioned at the bottom

right corner of the screen. 16.

The code screen will then appear. Press the arrow icon

17.

Once the arrow icon is pressed the unit will automatically turn off.

18.

Turn the unit on and select twin channel, allow the pump to stop running,

19.

Connect the pressure to the right cuff

20.

Inflate the cuff to 300, 600, the pressures must read 288-312 & 576624 respectively

21.

Select left cuff and allow pump to stop

22.

Test with cuff and pressure gauge at 300 & 600 mm Hg as per paragraph 20

23.

Ensure that pressure does not overshoot during inflation. If it does adjust slow deflate/inflate valve

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11.

Mechanical Assembly

Below explains the correct way to disassemble and re-assemble the tourniquet unit -

Disconnect mains electrical socket form rear of case

-

Remove the unit from the stand

-

Lay unit onto its back

-

For access to pump, battery & power supply unscrew the two M5 Screws located underneath the unit

-

Keep the unit laying on its back

-

Unscrew the two M5 screws on the front of the unit

-

Unscrew the two M3 screws on each side of the unit

-

As you turn the unit back onto its feet hold the plastic moulding. This is to avoid the front panel from pushing out and breaking the touch screen

-

Gently pull the front panel from the case, ensuring the cuff connectors catches are pushed down, Note: observe electric shock warning sticker located on the main PCB.

-

The front panel can now be pulled forward at the top and laid on the bench in front of the case

-

To gain access to pump, battery & power supply grip one of the reservoirs, gently tip the reservoir back and with the front panel gently pull the bottom of the reservoir which will bring the tray etc. with it,

-

Lay front panel and tray at right angle to the front of the case, ensure none of the tubes have been pulled off See fig 1 below,

Fig 1 -

To close the case reverse the above procedure ensuring all tubes are not trapped or linked

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12.

Setting slow Deflate/Inflate

The valve controls the slow deflate and the fine adjustment on the inflate.

Check by: 1.

Wrap a 110mm x 1080 cuff around a solid cylindrical object with the strap attached tightly

2.

Plug cuff into the black channel

3.

Inflate the cuff to 300mmHg

4.

Obtain stop watch to time how long the slow deflate takes to get from 300mmHg to 100mmHg,

5.

Select slow deflate and start the stop watch

6.

The unit should reach 100mmHg between 45-60 seconds

7.

If it reaches 100mmHg within this time then the fine control valve is set correctly

8.

If it does not reach 100mmHg in this time then the valve needs to be reset, (see List below)

9.

Repeat above procedure for the other channel.

Set By 1.

Disassemble unit as per section 11

2.

Plug cuff into channel to which you are setting

3.

Locate the valve to which needs to be set (example if the black channel, valve located same side of the tray as the cuff socket, in the corner of the tray. The valve is grey with a control knob on top)

4.

Before you can change the setting you must un-lock the silver lock nut located underneath the knob

5.

Lift the front panel up whilst also holding the knob of the valve (Note keep your hand away from the high voltage area on the main board PCB)

6.

Inflate the cuff to 300mmHg

7.

Select slow deflate and start stop watch

8.

Screw the knob into the valve to decrease the flow and unscrew the knob to increase the flow,

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9.

Keep inflating the cuff and slow deflating the cuff until you get the correct time taken to reach 100mmHg.

10.

Lock down the lock nuts again on the valve(s)

11.

Deflate system and disconnect cuff

Setting Regulator The regulator controls the flow of air travelling from the reservoirs to the system itself. If the adjustment is incorrectly set then the cuff will either under inflate or possibly damage the system.

1.

Disassemble the unit as per Section 11

2.

Locate the pressure regulator (located between the cylinders near the front of the tray),

3.

Pull the ‘T’ connector located at the back of the tray off of the piece of tube linking the ‘T’ connector to the pressure regulator

4.

Take the calibration test hose 2 and unplug the ‘T’ part which is pushed into the bottom of the ‘Y’ connector, then connect the ‘Y’ connector to the outlet of the pressure regulator

5.

The Digitron pressure gauge should now be linked up to the outlet of the pressure regulator,

6.

Turn on digitron

7.

Select mbar on the digitron

8.

Turn on unit

9.

let the pump fill the system and turn off

10.

The pressure showing on the digitron should be between 1200 and 1400. If it is then the pressure regulator is set correctly

11.

if the does not show between 1200 and 1400 then the pressure regulator needs to be re-set

12.

Unlock the lock nut on the regulator to enable you to then to alter the setting

13.

Turn the knob of the regulator clockwise to increase the flow and anticlockwise to decrease the flow. The pressure should always be read when the pump has stopped pumping.

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14.

Once the reading on the regulator shows between 1200 and 1400mbar lock the lock nut back down again. Place nail varnish onto the lock nut to ensure that its locked.

15.

Disconnect the digitron

16.

Re-connect the ‘T’ connector to the pressure regulator outlet

17.

Ensure all tubes are connected securely

To replace the regulator

Disconnect the output tube from the regulator. Turn the tray upside down and unscrew the t-piece from the base of the regulator Unscrew the nut and remove the regulator assay Unscrew the brass fitting from the regulator Screw the brass fitting to the new regulator to 2.3Nm max. Any more and you will break the thread from the bottom of the regulator. Fix the regulator assay to the tray with the nut and replace the t-piece, making sure the 7mm nut is not over tightened. Adjust the regulator output pressure and seal as in the previous section.

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