Air Bubble Technical Training Guide

Principle of the ultrasonic air detector

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mV Emitting ceramic

receipting ceramic

water threshold

T Water transmits the ultrasonic signal very well L. Meunier 10/06/2008

Principle of the ultrasonic air detector

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mV Emitting ceramic

receipting ceramic threshold

air T Air reflects the ultrasonic signal L. Meunier 10/06/2008

How is the size of the bubble calculated ?

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mV Emitting ceramic

receipting ceramic threshold

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L. Meunier 10/06/2008

How is the size of the bubble calculated ?

Tube

mV Emitting ceramic

receipting ceramic threshold

T

L. Meunier 10/06/2008

How is the size of the bubble calculated ?

Tube

mV Emitting ceramic

receipting ceramic threshold

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L. Meunier 10/06/2008

How is the size of the bubble calculated ?

Tube

mV Emitting ceramic

receipting ceramic threshold

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L. Meunier 10/06/2008

How is the size of the bubble calculated ?

Tube

mV Emitting ceramic

receipting ceramic threshold

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L. Meunier 10/06/2008

How is the size of the bubble calculated ?

mV

threshold

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T The time during which the signal of air is received is used to calculate the volume of the air bubble, according to the formula : V = T x Flow Rate

L. Meunier 10/06/2008

How is the size of the bubble calculated ?

mV

threshold

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18 s example : at 100ml/h, air is detected during 18 seconds V = T x Flow Rate = 18 x100 / 3600 = 0.5 ml

L. Meunier 10/06/2008

• Nepean Neonatal • TV/15min 10µ • BF: 0µ • Nepean Paeds • TV/15min 100µ • BF: 20µ • Nepean Adult • TV/15min 500µ • BF: 50µ © Copyright Fresenius Kabi Australia Pty Limited

L. Meunier 10/06/2008

• Greater Southern AHS Epidural • TV/15min 150µ • BF: 50µ • NSCC AHS Paeds • TV/15min 100µ • BF: 70µ • Greater Western AHS Neonatal • TV/15min 150µ • BF: 20µ © Copyright Fresenius Kabi Australia Pty Limited

L. Meunier 10/06/2008

• RHW Adult • TV/15min 150µ • BF: 50µ • SESIAHS Neonatal • TV/15min 100µ • BF: 20µ • SESIAHS Adult • TV/15min 150µ • BF: 50µ © Copyright Fresenius Kabi Australia Pty Limited

L. Meunier 10/06/2008

Algorithm of FK infusion pumps

Configuration of air bubble alarm our pumps :

 = 250 µl /15 min  50 µl

Accumulation adjustable from 10 up to 2000µl (Volumat)

“filter” adjustable from 0 up to 250µl (volumat)

L. Meunier 10/06/2008

Algorithm of FK infusion pumps

mV

At start-up, it is not possible to know the size of the bubble, so the pump activates the air alarm if the signal is below the threshold. The infusion can not be started. threshold

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L. Meunier 10/06/2008

Algorithm of FK infusion pumps

mV

For a single bubble, the air alarm is activated when the bubble is above 250 µl. The infusion is stopped. threshold

T 15 s example : at 60ml/h, air is detected during 15 seconds V = T x Flow Rate = 15 x60 / 3600 = 0.250 ml = 250 µl

L. Meunier 10/06/2008

Algorithm of FK infusion pumps

mV

In case many bubbles are detected, the air alarm is activated when the total volume of air is above 250 µl during the last 15 minutes* of infusion, not taking into account the small bubble below 50µl

threshold

T e.g. at 60ml/h

9s

2.4 s

6s

Vol. air bubble

150 µl

40 µl

100 µl

Vol taken in account 150 µl

0 µl

100 µl

Cumulated volume

150 µl

250 µl

150 µl

* sliding period of 15 minutes

These 2 small bubbles do not activate the air alarm

the air alarm is activated by the 3rd bubble

L. Meunier 10/06/2008

How to limit air bubbles? +4°C

+25°C

Many fluids (especially TPN solutions) contain significant amount of dissolved gas. During the warming up, small bubbles are released. These small bubbles do not move at the same speed as the liquid, which may activated the air bubble alarm Recommendation: all fluids or drugs to be infused should be at room temperature (+18 to +30°C) before being infused

L. Meunier 10/06/2008