3100b theory of operation and controls. viasys healthcare, inc. 3100b theory of operation and...
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3100B Theory of Operation and
Controls
VIASYS Healthcare, Inc.
3100B Theory of Operation and Controls
•Approved for sale outside the US in 1998 for patients weighing > 35 kg failing CMV
•Approved September 24, 2001 by the FDA for sale in the US
VIASYS Healthcare, Inc.
SensorMedics 3100B
• Electrically powered, electronically controlled piston-diaphragm oscillator
• Paw of 5 - 55 cmH2O
• Pressure Amplitude from 8 - 130 cmH2O
• Frequency of 3 - 15 Hz• Inspiratory Time 30% -
50%• Flow rates from 0 - 60 LPM
VIASYS Healthcare, Inc.
Paw is created by a continuous bias flow of gas past the resistance (inflation) of the balloon on the mean airway pressure control valve.
VIASYS Healthcare, Inc.
Principle of the SM 3100A HFOV
“Super-CPAP” system to maintain lung volume
VIASYS Healthcare, Inc.
To pressurize the patient circuit, the Reset / Power Fail button must be pressed and held until the mean airway pressure is at least 5 cmH2O
VIASYS Healthcare, Inc.
Oxygenation
• The Paw is used to inflate the lung and optimize the alveolar surface area for gas exchange.
• Paw = Lung Volume
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Optimizing Hemodynamics
• PVR is increased with:– Atelectasis
• Loss of support for extra-alveolar vessels
– Over expansion• Compression of
alveolar capillary bed
• The lung must be recruited, but guard against over expanding.
VIASYS Healthcare, Inc.
Primary control of CO2 is by the stroke volume produced by the Power Setting.
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Alveolar ventilation during CMV is defined as:
F x Vt Alveolar Ventilation during HFV is defined as:
F x Vt 2
Therefore, changes in volume delivery have a more significant affect on CO2 elimination than frequency
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Pressure transmission
Gerstmann D.
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Pressure transmission HFOV
P
T
proximal
trachea
alveoli
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• The % Inspiratory Time also controls the time for movement of the piston, and therefore can assist with CO2 elimination.
• Increasing % Inspiratory Time will also affect lung recruitment by increasing delivered Paw.
VIASYS Healthcare, Inc.
Inspiratory / Expiratory Ratio
• I/E Ratio adjustable with Inspiratory time control
• Inspiratory time = Forward movement piston• Expiratory time = Backward movement
piston• Backward movement piston = active
exhalation ! • Recommended Insp. time = 33%++
----
30%
70%
Inspiratory time adjustable: 30% - 50%
VIASYS Healthcare, Inc.
Secondary control of PaCO2 is the set Frequency.
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Regulation of stroke volume
Stroke volume
• The stroke volume will increase if– The amplitude increases (higher delta P) – The frequency decreases (longer cycle time)
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Piston Centering is automatically regulated by the instrument and requires no operator intervention.
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The Start / Stop button is used to start and stop the oscillator. The oscillator may be stopped without a complete loss of mean airway pressure.
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Alarms
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Preset High and Low mean airway pressure alarms.
Upon activation the oscillator will stop and the circuit pressure will vent to ambient.
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Activation of the high mean pressure alarm will trigger the Auto Limit System.
The Auto Limit System will open the “blue” limit valve on the circuit and vent pressure.
The valve will then repressurize to it’s normal operational state.
VIASYS Healthcare, Inc.
After resolution of the fault condition the visual alarm can be cleared by
pressing the Reset / Power Fail Button
VIASYS Healthcare, Inc.
Activation of the low mean airway pressure alarm will only
provide audible and visual alarms.
The visual alarm will automatically reset after the fault
condition has resolved
VIASYS Healthcare, Inc.
The source gas low alarm will provide only a visual indicator if either of the high pressure gas supplies falls below 30 psi.
VIASYS Healthcare, Inc.
The battery low alarm will provide only a visual indicator when the nine volt alarm battery needs replacement.
VIASYS Healthcare, Inc.
The oscillatory overheated alarm will provide only a visual indicator if the linear motor temperature
exceeds 150 degrees Centigrade.
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The oscillator stopped alarm will provide audible and visual indicators if the oscillatory amplitude is at or below 7 cmH2O and the oscillatory subsystem is energized, (as indicated by the illumination of the green LED on the start stop button)