freequently asked questions and downloads about solutions for pulmonary studies using plethysmography models

frequently asked questions

• what is a plethysmograph?
• what are the advantages of studying sedated animals?
• what is a pneumotachograph?
• what is penH
• what is transpulmonary pressure?
• what is the nebulization controller used for?
• is it possible to control more than 8 nebulization heads from iox2?

what is a plethysmograph?

A plethysmograph is a closed chamber in which pressure changes due to the animal's breathing are measured. Plethysmography is a widely used technique for studying pulmonary function.

The three principal plethysmography models are used for studying:

• conscious freely moving animals
• conscious restrained animals
• sedated animals

In all models, one measures flow and/or pressure changes associated with each breathing or ventilation cycle.

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what are the advantages of studying sedated animals?

The study of sedated animals allows one to calculate lung resistance and dynamic compliance using flow and pressure measured directly.

One can combine different models. For example, bronchoconstriction data obtained in conscious animals (the indirect measure penH) can be confirmed in studies using anesthetized animals.

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what is a pneumotachograph?

A pneumotachograph consists of one or more fine metallic meshes through which air passes. The mesh is designed so that there is a linear relationship between air flow and pressure difference on each side. This makes it possible, after calibration, to calculate the flow rate from the measured difference in air pressure.

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what is penH ?

penH (enhanced pause) is a parameters used in whole-body plethysomgraphy as a measure of bronchoconstriction.

Bronchoconstriction causes pulmonary resistance to increase so that the pressure changes associated with breaths no longer reflect the animal’s respiratory flow. Flow-based parameters become usable; however, the pressure waveform shows characteristic changes (compared to a normal breathing pattern waveform), which are quantified by Penh. Penh values above 1 are usually indicative of bronchoconstriction.

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what is transpulmonary pressure?

Transpulmonary pressure is the pressure across the lung (without the thorax cage).

It is calculated as follows (in anesthetized plethysmography):

P_{transpulmonary} = P_tracheal - P_pleural

Esophageal pressure may be used as an approximation of pleural pressure.

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what is the nebulization controller used for?

The different plethysmography setups from emka TECHNOLOGIES - for studying conscious freely moving, conscious restrained or sedated animals - can be fitted with an aerosol delivery system. nebulizationCONTROLLERS control the nebulization heads, which generate the aerosol.

The use of nebulizationCONTROLLERS brings additional functionalities to the plethysmography setup:

• remote control of nebulization from iox2 software
• incorporation of nebulization tasks into iox2 protocols
• adjustment of nebulization rate

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is it possible to control more than 8 nebulization heads from iox2?

The standard acquisition card has 8 bits, each of which can be assigned one head.

If your computer has the necessary slot, it is possible to fit another card to provide additional bits.

Please contact emka TECHNOLOGIES for information about this possibility.

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