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Publication 5420-009 REV1.0
Introduction
Theory of Operation
The VentElite was designed for animal research applications and is intended for use on
subjects ranging in size from mice to guinea pigs. The design goal of this ventilator was
to maintain versatility and ease of use while fostering safe and physiologically accurate
mechanical ventilation conditions.
The VentElite utilizes advanced technologies to precisely control respiration profiles.
The VentElite has two operating modes, Volume Control and Pressure Control, and
allows users to easily toggle between these two modes via the Settings button on the
large touch screen. The Volume Control mode delivers the desired tidal volume to
the subject by precisely controlling the stroke of the piston. Since the actual stroke
length, and therefore tidal volume, may be modified for a given stroke, sigh breaths are
supported. Similarly, since stroke speed is precisely controllable during inspiration and
expiration, variable inspiration-to-expiration (I:E) ratios are also supported. A pressure
sensor continuously monitors the airway pressure to alert the user of over- and under-
pressure conditions.
The Pressure Control mode of the VentElite allows the user to set the peak inspiratory
pressure (PIP) value. Flow rates are automatically adjusted by changing the tidal volume
while keeping the respiration rate constant. The stroke is adjusted in a manner in which
the PIP is reached near the end of the piston stroke. This ensures that the subject, which
has a higher airway resistance than the airway path within the ventilator, receives the
majority of the expected tidal volume and that the unit does not prematurely terminate
the piston stroke. Manual adjustment of the inspiratory flow rate is not required.
The VentElite offers built-in Positive End Expiratory Pressure (PEEP) capability, allowing
a PEEP setting via the touch screen user interface of up to 10 cmH
2
O. Another feature of
the VentElite is the ability to perform Inspiratory or Expiratory Hold. The user can enter
the desired hold time and initiate inspiratory or expiratory hold by simply pressing the
Insp. Hold/Exp. Hold button on the user interface.
