1. Suction Machines
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),

2. Clinical Use Blood from the surgical field
Removing ingested toxins (stomach pump)
Unwanted fats (liposuction)
Mucosal secretions from the esophagus

3. Clinical Use
In the developed world one normally uses the wall vacuum system instead of suction pumps

4. History
The existence of a vacuum force was first discovered by Otto von Guericke in 1650 in an experiment where air molecules were removed from a sealed container. Once removed, the container's space became a vacuum. Not long after this discovery, the vacuum pump was invented to help chemists better understand the properties of gases. An empty container allowed chemists to refill it with different gases and study them in their pure forms, without the interference of air gases. Since then, vacuum technology has developed to the point where the full effects of this force can be utilized within a variety of applications.
Today, there are three main types of vacuum pumps--compressed air pumps, electromechanical pumps and entrapment pumps.
Compressed air pumps work to increase the pressure of a gas by decreasing the space that it occupies. They do this by forcing gas molecules through a small space, like a nozzle. When compressed gas is introduced into a high pressure environment, it creates a vacuum effect.
Electromechanical pumps trap air inside moving mechanical parts--like rotors--then force it through a pump device. This process creates a vacuum effect. These are motorized devices that require electricity to run.
Entrapment pumps are designed to catch gases and confine them in a sealed space, or chamber. All three methods have been adapted for use in various applications.
The piston pump of Ctesibius (an engineer from Alexandria, Egypt, 3rd century BC) was described by Philo of Byzantium (2nd century BC) because Ctesibius’ book was lost. It was a force pump and was submerged in water; (Fig. 1)[1].

5. Principles of Operation
Pressure units:
millimeters of mercury (mm Hg)
pascals (Pa or kPa)
inches or centimeters of water (inH2O or cmH2O)
pounds per square inch (psi)
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
1 mmHg = kPa = 1.36 cmH2O = inH2O = psi

6. Principles of Operation
Elements
Source of suction (Mechanic or thermal pump)
Tubing
Collection bottle
Canister or bottle
Manometer
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA

7. Principles of Operation
Mechanical Suction Source (hollow input tube)
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),

8. Principles of Operation
Mechanic Source of suction (diaphragm type)
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),

9. Principles of Operation
Electric pump induction motor
Stator with windings
Squirrel Cage rotor
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
Mirsad Todorovac (2006), 3 phase synchronous electric motor [graphic]. Retrieved from

10. Principles of Operation
Electric pump induction motor
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
S.J. de Waard (2011) Opengewerkte elektromotor [photograph]. Retrieved from

11. Types of Pumps
Rotary
Vane
Piston

12. Principles of Operation
Mechanical Sources of Suction
- Electric motor driven
- Hand/Foot Pumps
- Venturi with compressed air
- Vane type 
- Diaphragm type
- Screw type
- Piston type
- Typically 20-30inHg maximum
- Typically 20-30Lpm air flow
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA

13. Thermal/Thermotic Pumps
Pedal pump
Thermal Source of suction
coil in the unit heats up for approximately seconds
cooling creates a suction airflow and pulls fluid from the wound site
Typically mmHg suction maximum. 
Typically 1-2Lpm air flow

14. Principles of Operation
Collection bottle (hollow input tube)
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),

15. Principles of Operation
Collection bottle
Float valve should be in the last canister before the connection
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA

16. Principles of Operation
Fluid trap
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),

17. Operation Position the unit close to patient
Plug into AC power (do not use extension cords)
Attach first suction tubing from pump suction control to collection bottle outlet
Attach second suction tubing to collection bottle inlet
Ensure a rising float will block fluid flow to the pump
Check all components and connections for tight fit
Turn suction pump on (on/off electrical switch)
Crimp tubing coming from the collection bottle inlet
Adjust suction to desired level while observing vacuum gauge
Initiate suction procedure

18. Circuit
Malkin, Robert. Medical Instrumentation in the Developing World. Engineering World Health, 2006

19. Physical Methods of Microbial Control

20. Vertical Autoclave
Snelling, Guy. “Autoclave Validation-What is Really Required?.” Retrieved from:
autoclaves/background/Autoclave_validation_-_what_is_really_required.pdf

21. Commercial Examples
Massimiliano Mariani, (2009), A portable suction unit from an ambulance [photograph}. Retrieved from
R-E-A-L (2003), Suction device for use in dentistry [photoraph]. Retrieved from

22. Commercial Examples
Beukbeuk (2008), Medela breast pump [photograph]. Retrieved from

23. Safety One should have at least 3 pressure intensity levels:
Low (wound suction)
Medium (chest tubes)
High (airway and gastric suctioning)
The staff member using the suction unit should always wear protective gloves. The reason this is important is because it's the user's thumb that occludes a hole on the catheter and the secretions must pass directly under that hole. The chances of coming in contact with those
microorganisms are very high if gloves are not worn. They should also wash their hands immediately after suctioning and removal of the protective gloves. If the person using the suction machine is at risk of being splashed by secretions then eye and/or face protection
should be worn.

24. Common Problems Clogs Leaks Collection Bottles Electrical Motor
Pump valve contamination/corrosion or wear

25. Common Problems Clogs Tubes
Filters 3 micron size or barb-hose barb PTFE 
Lilly_M (2011) 0,22 ul PTFE filter [photograph]. Retrieved from

26. Common Problems Leaks Apply Water and soap
Public Domain Pictures, George Hodan (2012), Spray Bottle Spraying [photograph]. Retrieved from

27. Common Problems Tube leak Jar/lid leak (bad o-ring, possibly)
Tube blockage or kink
Bad motor
Bad power supply
No collection bottle
Float valve closes air pathway w/ full collection jar
No filter
Insufficient suction due to pump wear or corrosion.

28. Common Problems Electrical Pump
Vibration between the suction machine and the floor
Clogged bacterial filter
Insufficient pressure/suction
Ventilation grill obstructed
Suction control knob is set to a low setting
Vanes need replacing (in rotary vane style pump).
-Vanes are numbered and need to be replaced in order
Diaphragm needs cleaning or replacing
Brushes need cleaning
Motor needs lubrication

29. Preventive Maintenance
PM (daily)
Clean filters
Clean air vents
Ensure electrical plug and cord are in good condition
Sterilize jars, tubing, other components that come into contact w/ patient fluids between each use in solution of water, detergent, and disinfectant
Change bacteria filter if wet or discolored
Check collection bottle/jar for cracks, chips, and other damage
Make sure there is a sufficient supply of bacterial filters
Check that float valve moves freely
Ensure anti-static tubing is used
PM (1-3 months)
Clean or replace air intake filter
Clean brushes on motors as necessary
Inspect power cord and plug
Ensure vacuum works over full range of suction pressures if there is a control/knob
Verify that overflow valve (float valve) works properly when container is filled with water
Grounding resistance between chassis and ground pin should not exceed 0.5 ohms

30. Preventive Maintenance
Bearings cleaning
Hot light oil at ° F may be flushed through the housing while the shaft is slowly rotated
Light transformer oils, spindle oils or automotive flushing oils are suitable
Oils heavier than light motor oils, such as SAE 10, are not as effective
Automotive engine oils are not to be used. The detergents will leave deposits and restrict motor rotation

31. Preventive Maintenance
Calibration: Not possible in most models

32. Preventive Maintenance
One can check the pressure gauges value
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),
Pressure (mmHg) = Height of Water (in inches) ∗ 25.4 (mm/in) 13.6 (mmH20/mmHg

33. Suction Machine Troubleshooting
Robert Malkin, Engineering World Health, “Suction Machine: Use and Operation” (2006),

34. Summary Quiz Clinical Use History Specifications
Principles of Operation
Block Diagram
Commercial Examples
Preventive Maintenance
Common Problems
Test Procedures

35. Quiz – Suction Machine
What are the techniques to create vacuum?

36. Questions ❓