Hallowell Ventilator

The Hallowell EMC Model 2002 and 2000 are electronically controlled, time-cycled, pressure limited ventilators.

Time cycled -- Insures consistent, repetitious, dependable breathing.  The respiratory rate is adjustable from  6 - 40 breaths per minute (BPM).

Volume constant -- Insures that each delivered breath will have essentially the same volume, independent of changes in patient compliance and airway resistance.  The deliverable tidal volume (TV) range is from approximately 20 cc to 3,000 cc.

Pressure Limited -- Provides for patient safety by limiting the maximum working pressure (MWPL) to an adjustable pressure range of 10 - 60 cm H2O.

The Model 2002 Veterinary Anesthesia Ventilator is functionally equivalent to the Model 2000 with the following exceptions:

The Model 2002 ventilator is equipped with dual airway pressure alarms that monitor and sound when the peak inspiratory pressure (PIP) of any breath either exceeds the preset maximum working pressure limit (MWPL)  , or fails to reach 6 cm H2O as in the case of a disconnect  ..  The Low Supply Gas Alarm  , available as an option, would sound when the supply gas pressure falls below 35 psi, 2.4bar.

Available on all models of the 2002 and 2000 is the option of having an adjustable I:E Ratio control.  Normally, without this option,  the I:E Ratio is fixed at 1:2, that is, 1/3 of the period of each breath is inspiration and 2/3 of each breath is exhalation.  Regardless of the respiratory rate, the patient will always have 2/3 of the cycle to exhale.  This fixed I:E ratio can be fixed at a value other than 1:2 at no extra charge.

The adjustable range is from 1:1.5 to 1:4.  The pros and cons are that this option affords the operator more flexibility in dealing with animals that have compromised lung function.  But during anesthesia most patients are lung healthy and the addition of this control can add to the complexity of setting the ventilator.  For example consider that you have a hypocapnic patient.  To bring that patients CO2 level to a more normal range you must decrease the overall gas exchange, the Minute Volume (MV).  Without this option, only one knob controls the MV, that is the Volume control.  With this option; however, increasing the I:E ratio would also cause a reduction in MV.