The Morgan Plethysmograph Simulator consists of a sinusoidal rolling-seal pump with interchangeable isothermal chambers of approximately 2 and 4 Liters. It has been designed for verification of lung volumes measured by a plethysmography. The VTG Calibrator is controlled via a Bluetooth interface operated using either a Palm or Windows Mobile PDA. Pump frequency can be varied from 30 to 130 cycles per minute. Each chamber is manufactured to precise standards providing two volumes within physiological ranges for VTG measurement verification.

Detailed test certificates are provided showing how each chamber volume is determined and verified. The device should be utilized with any body plethysmograph for routine quality assurance.

Why routine quality assurance is important

The body plethysmograph is regarded as the most reliable instrument to obtain lung volume data in all test subjects regardless of obstructive lung disease. Whereas traditional gas dilution techniques (closed-circuit helium dilution and nitrogen washout) are compromised by gas distribution and airway communication in the lungs, the plethysmograph makes measurements by pressure change and can access those 'hidden' lung volumes.

For measurements of plethysmography, the subject is enclosed in a sealed cabin (enclosure) equipped to measure pressure, flow or volume changes. The differential pressure measurements are of Box Pressure (the pressure changes measured within the sealed cabin) and Mouth Pressure (the alveolar pressure changes recorded at the mouth when the patient valve is occluded). Flow is measured using the principle of pneumotachography; the flow signal is integrated to obtain Volume. A change in the volume of air in the lung from breathing maneuvers can be estimated from the expansion or the compression of gas in the plethysmograph.

• The most common measurements made using a body plethysmograph are thoracic gas volume (VTG) and airways resistance (Raw).
• The Plethysmograph Simulator provides an independent quality control for VTG measurements.

Bluetooth PDA Control

Control and operation of the simulator is via Bluetooth communication from a hand-held PDA. Three pre-set programs provide pumping frequencies of 40, 60 and 90 cycles which can be run with one simple command. The PDA program also allows the user to edit the pre-set options or customize any frequency and pump duration from 30 to 130 cycles.

Using the Simulator with any make of Body Plethysmograph

Once the simulator has been placed inside the cabin and attached to the patient valve, the technician simply runs the VTG software as if they were testing a patient. When required by the software, the pump on the simulator is started using the hand-held PDA. We recommend that a series of 4 or 5 measurements be taken and averaged for evaluation of accuracy. Given the correct pumping frequency and proper plethysmograph calibration, it is expected that VTG results on either the large or small chamber be better than 5% of the certified volume.

Plethysmograph Simulator Certified Volume

Each isothermal vessel certificate details the calculated volume precisely obtained by dimensional measurement and gravimetrical adjustment for copper volume.

The certified volumes include the following

• All volumes contained inside the simulator base module
• Volume of the individual isothermal vessel
• Volume of the connecting hose

Please Note: Since measurements of VTG are typically triggered in software by a closing of the patient valve at end-expiration, the internal volume is measured from the full down-stroke of the pump piston.

To establish the most accurate volume when using your plethysmograph, you will need to account for any added volume.

Added volumes typically include:

• Connecting piece to the patient valve (filter or adaptor)
• Valve Dead Space

Plethysmograph Simulator Package

Each quality control instrument is supplied with a custom-designed carrying/storage case, PDA, appropriate mains chargers and detailed operation manual.

Online Video Demonstration

Click here to watch a few minute video about the Morgan Plethysmograph Simulator.

Call To Setup An Appointment

Call our staff at 978-521-4440 and they will setup a time for a complete product demonstration.

Plethysmograph Simulator Brochure

Plethysmograph Simulator is the culmination of manufacturing and pulmonary testing expertise that has no equal. DOWNLOAD PDF