Lecture 2 Machine Checkout

When should a machine checkout be completed?

- daily

- after a machine is moved

- after vaporizers are changed

How are the steps of the machine checkout divided? (7)

1. emergency ventilation equipment

2. high pressure system

3. low pressure system

4. scavenging system

5. breathing system

6. manual and automatic ventilation systems

7. monitors

8. final position

What is the first step?

verify backup ventilation equipment is available and functioning (ambu bag, auxilary o2) (also suction?)

What is included in the backup ventilation equipment? (2)

1. auxiliary oxygen cylinder

2. manual ventilation device (AMBU bag)

How do you check the availability and function of the emergency oxygen supply?

verify that oxygen is delivered when you open the auxiliary oxygen supply valve (the auxiliary oxygen supply will only deliver oxygen if there is adequate oxygen pressure in the tank)

What do you do if the auxiliary oxygen pipeline doesn't work?

make sure that you have an O2 cylinder (other than the cylinder on the back of the machine)

What does AMBU stand for?

artificial manual breathing unit

What is the second step?

check oxygen cylinder supply

How do you check the check the oxygen cylinder supply?

1. turn the machine master switch on

2. disconnect the O2 hose from the pipeline

3. close the O2 tank valve

4. push the O2 flush valve to bleed O2 from the system

5. you should hear and see the low O2 pressure alarm

6. open the O2 cylinder and verify that the O2 cylinder pressure is at least 1000 psi

7. test the fail-safe valve by dialing N2O and O2 gas flows to approximately 5 L/min

8. close the O2 tank

9. as O2 pressure falls, you should observe that N2O flow turns off before losing all O2 flow

10. when O2 pressure falls to 0, you should hear and see the no oxygen pressure alarm

11. set all gas flows to minimum and reconnect the central O2 pipeline supply

What is the third step?

check central pipeline supplies

What should the pipeline pressure gauge read?

50 psi

What is the fourth step?

check initial status of low pressure system

How do you check the initial status of the low pressure system?

1. close flow control valves and turn vaporizers off

2. check the fill level and tighten vaporizers' filler caps

What is the fifth step?

perform leak check of machine low pressure system

How do you perform a leak check of the low pressure system?

1. turn the system switch to standby

2. open all gas flow valves 1 and a half turns (since the machine is in standby mode, you will not get any gas flow)

3. disconnect the breathing circuit from the machine to have easier access to the common gas outlet

4. locate the suction bulb in one of the machine drawers

5. test the suction bulb by occluding the connector end with your finger and by verifying that the bulb remains deflated after you squeeze it

6. open the auxiliary common gas outlet switch by swinging the lever down

7. attach the suction bulb to the common gas outlet and squeeze the bulb several times until it stays deflated

8. verify the bulb remains deflated for at least 10 seconds

9. check each vaporizer for a leak by opening a vaporizer, squeezing the bulb several times until it stays deflated, and verifying that the bulb remains deflated for 10 seconds

10. during those 10 seconds, check if the vaporizer interlock system works by trying to open the other vaporizers

11. repeat the process for each vaporizer

12. close the auxiliary common gas outlet by lifting it up to its original position and removing the suction bulb from the common gas outlet

after this (NOT A PART OF LEAK CHECK), turn the machine back on, check flowmeters work/don’t deliver hypoxic mixture

What is the sixth step?

turn on machine master switch and all necessary electrical equipment

- verify machine display turns on

What is the seventh step?

test flowmeters

How do you calibrate the flow sensors?

1. open the hatch under the flow sensor module

2. remove it by pushing up on the tab under the module and pulling it straight out

3. push excess water out of the machine by pushing the drain button below the flow sensor module while simultaneously pushing in the oxygen flush valve for 10 seconds

4. to calibrate the oxygen sensor to room air, locate the oxygen sensor below the flow sensor module and remove it by turning it counterclockwise

5. let the oxygen sensor hang freely

6. press the menu button in the system display unit

7. scroll down and choose the setup/calibrate

8. choose the oxygen sensor calibration option and press start

9. choose the 21% option followed by start cal

10. once calibration is complete, replace the oxygen sensor and close the hatch

How do you check the flow meters?

1. adjust the flows to their full range

2. if you first increase the N2O flow to maximum, you will see that O2 flow will increase

3. increase the O2 maximum and confirm the inability to create a hypoxic mixture

How do you confirm the inability to create a hypoxic mixture?

1. turn the O2 flow off and observe a simultaneous reduction in the N2O flow off

2. turn the O2 valve off

Based on the video, how do you check the low pressure system?

First leak check, then

1. set the system switch to on

2. calibrate flow sensors

3. calibrate the oxygen monitor to room air (21%)

4. test the flowmeters