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Pulmonary Function Test • Publication 014181-001 Rev 02 • www.datasci.com ©2023 Data Sciences International
Compressed Air Source
Every PFT chamber model other than the mouse chamber requires a compressed air source to articulate the
pneumatic control valves on the manifold. These valves drive FRC cylinders and the Fast Expiration
cylinders. This includes the Rat/GP, Rabbit, Ferret, and Primate chambers.
The compressed air source must deliver 40 to 50 PSI. If the pressure is higher than 60 PSI, the pneumatic
valves will be damaged. The air sources include low noise air compressors with a pressure regulator, or a
laboratory air source with a pressure regulator.
DSI offers a low noise air compressor for sale. The models have varied over the years, so model specific
details are not included in this manual. If you purchased your compressor from DSI, please see the
manufacturers product manual that was included with you unit. A compressor purchased from DSI will also
include a kit that includes the tubing and fittings you will need to connect the compressor to the chamber.
Please contact your DSI sales representative or DSI technical support for more information.
Chamber Manifold Design
The manifold connects the trachea of the anesthetized animal to the valves that control each test. Although the
manifolds for the mouse, rat or monkey do not look similar, they are identical in theory and operation.
Not all the PFT tests are “forced.” For example, the FRC test operates from the driving pressure of the animal. All
the PFT tests require tracheal connections. Gas flow paths must be switched to accommodate all the tests in rapid
sequence. Most of the connection switching is performed automatically, under computer control.
The features of the manifold are described below:
(V
FRC)
This valve is a low resistance normally open valve that the animal can breathe
through when the test is not running. This valve is closed during each test.
(V
FExp
)
This valve is closed all the time except for expiration during the Fast FV test. This is
a low resistance valve which (when open) exposes the trachea directly to the
(V
Exp
)
This valve is closed all the time except for expiration during the Quasistatic PV test.
This valve draws air from the trachea at a rate set by the adjustable valve on the
(V
Insp
)
This valve is open to either clear CO
2
build up in the dead-space of the manifold, or
to force an inspiration.
2
This port is used to calibrate the pressure sensor.
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