The fluidic logic employed in the design of devices capable of High Frequency Percussive Oscillatory Ventilation (HFPOV™), allows a major reduction in transition penalties when compared to HFOV devices. The primary device for HFPOV™ is called an Oscillatron®, which has cyclic transition penalties at 900 cycles per minute of about 14 milliseconds compared to piston and magnetically servoed HFOV ventilators with transition penalties approaching 42 milliseconds. By subtracting 14 from 42 one can see that the time for effective reciprocating tidal exchange gradients is increased by 28 milliseconds in the Oscillatron® fluidic HFPOV™ design.

It follows that a reduction in the high frequency delivery frequencies will result in more time for tidal exchange by any dynamic (push-pull) oscillator design. However, without the intrapulmonary gas-mixing enhancement provided by percussive endobronchial gas mixing, the potential for CO2 recruitment will be minimal.

By modulating the tidal delivery waves of certain CMV ventilators, the clinical efficacy can be increased with a potential reduction in PIP and FIO

It follows that increasing the blood/gas interface by mechanically increasing the D/FRC with an elevated CPAP alone could serve to increase PaO2. However, without a concomitant tidal exchange sufficient to "wash out" CO2, the patient could die (nice and pink) from a CO2 narcosis.

THE U S FDA CLEARED THE PERCUSSIONAIRE® OSCILLATRON® FOR MARKETING ON OCTOBER 16, 1989.

OVER THE MANY YEARS, THE VOLUMETRIC DIFFUSIVE RESPIRATION CONCEPT (VDR®) HAS TAKEN PRECEDENCE OVER THE OSCILLATRON® AS A UNIVERSAL VENTILATOR.

This allowed other piston and magnetically servoed high frequency oscillators to increase their cyclic frequency, based upon Dr. Bird’s prior state of the art available on May 28, 1976.

Essentially, the "Oscillatron 1" defines the extension of the (positive phase) Phasitron® enabling a potential sub ambient expiratory phase.

The clinical concept of Volumetric Diffusive Respiration (VDR®) has confirmed the clinical efficacy of combining "Diffusive Percussive Ventilation" with the traditional Convective CMV ventilation of the lung. Therefore, it became a natural timely transition to enable standard conventional CMV ventilators to increase their level of clinical efficacy by combining "Diffusive Intrapulmonary Percussive Ventilation" with the CMV programmed convective tidal exchange. The Oscillatron® alone (among all other HFOV ventilators) enables the modulation of a conventional tidal exchange (with PIP’s approaching 100 cm H2O), providing for the enhanced diffusion of the intrapulmonary gases in lungs with very low compliance.

The Oscillatron® is essentially a unique Canister which is servoed by the Phasitron to generate a potential sub ambient phase during High Frequency Percussive Oscillatory Ventilation (HFPOV™).

The fluidic design employed in the percussive Oscillaton® logic is advanced by a "Differential Flow Interrupter Cartridge" with near instantaneous opening and closing thus providing repetitive flow interruption to an encapsulated sliding venturi injector exhalation valve called a Phasitron®".

In turn, the Phasitron® near instantaneously pressurizes an encapsulated diaphragm centered in the chamber by opposing counter springs. The percussive forward movement of the diaphragm injects a high velocity tidal volume of gas into the breathing circuit to modulate a selected positive pressure at the patient’s proximal airway. The inspiratory percussive flow gradient is near instantly reversed, creating an immediate follow on expiratory flow gradient, which generates a potential distal–proximal sub ambient pressure gradient at the proximal airway.

1.  A virtually unlimited source of regulated high pressure gas exerts continuous pressures of about 40 psig against the flow interrupter valve gate. When the flow interrupter cartridge valve gate near instantaneously opens, a sustained percussive burst of regulated high pressure gas is released against the jet of the Phasitron® venturi for a timed interval.

When the design inertia of a Magnetic HFOV is compared with the Oscillatron’s percussive pneumatically servoed diaphragm, the transition penalty is about 14 ms. for HFPOV compared to about 42 ms. for a magnetically servoed HFOV oscillator diaphragm. The magnetic HFOV design, mandates an elevated TRANSITION PENALTY when compared to the Oscillatron’s HFPOV design. Functionally, the Oscillatron (HFPOV) with transition penalties of 14 milliseconds as opposed to 42 milliseconds for the magnetic HFOV, possesses a more effective intrapulmonary "gas exchange time" for a sub tidal gas exchange.

Most important, the percussive Oscillatron® HFPOV design clinically requires less than half of the required scheduled CPAP of the magnetically HFOV design. High Frequency Percussive Oscillatory Ventilation (HFPOV) compared to High Frequency Oscillatory Ventilation (HFOV) has a greater sub ambient expiratory flow gradient time. Thus, with a more effective expiratory distal to proximal flow gradient a neutral i/e ratio of 1:1 is allowed without mechanically creating an inadvertent PEEP.

8.  Uniquely, the fluidic Oscillatron® design enables successive near constant sub tidal (stroke) volume deliveries for the modulation of convective tidal intrapulmonary CMV Pressures from 5 to 100 cm H2O.

9.  The fluidic design allows the end expiratory position of the diaphragm to compensatorily over-travel into the servoing chamber in proportion to the end inspiratory proximal airway pressure increase.

10.  This diaphragmatic re-set allows the Oscillatron® to modulate the tidal waves of CMV ventilators with near constant sub tidal volumes, with peak delivery pressures approaching 100 cm H2O.

11.  In order to have a clinically effective percussive injection of a tidal volume into the breathing circuit, the available injection time at each frequency must maintain a near constant flow gradient, with sufficient time to deliver a scheduled tidal exchange. Without a near immediate effective expiratory potentially sub ambient flow gradient, an inadvertent PEEP would increase with frequency, mandating an increased D/FRC.

It follows that:

The less clinically effective the intrapulmonary mechanical mixing to enhance endobronchial diffusion, the greater the mandate to increase the blood/gas interface with:

An Increase in the Final Inspiratory Oxygen Concentration (FIO2).

Therefore, the greater the high frequency pulsed tidal exchange volume, the less the required CPAP and FIO2 to maintain acceptable PaO2 and PaCO2.

Technologically, it is the high transition penalty mandated by the design of piston and magnetic HFOV oscillators that serves to inhibit their clinical efficacy. The fluidic dynamic (push-pull) percussive Oscillatron® design reduces the Oscillation transition penalty from about 42 milliseconds for HFOV to about 14 milliseconds for HFPOV™.

This major reduction in the HFPOV™ transition penalties allows a more effective intrapulmonary gas mixing, greatly reducing the required CPAP and FIO2 requirements of HFPOV™, and effectively reducing the mean intrathoracic pressure and the imposition upon right heart function". HFOV requires CPAP values approaching 20 cm H2O.

HFPOV requires less than half of these CPAP values. Therefore, HFOV requires a positive i/e ratio while HFPOV with CPAP values under 10 cm H2O, requires only a neutral 1:1 i/e ratio with the greater Proximal/Distal pulmonary airway flow gradients.