Pneumotachometers

Pneumotachometers

Calibrated Pneumotachometers for respiratory flow measurements.

Pneumotachometers may be unheated, or heated to avoid errors due to changing flow resistance with moisture condensation. A measurement system will require the pneumotachometer, heater if required, differential pressure transducer, appropriate carrier amplifier or adaptor, and recording system.

FLEISCH Pneumotachometers

A wide range of pneumotachometers, covering a range of flow rates appropriate for mice to adult athletes. The differential pressure of each model is 6.25 mm water at its nominal flow rate.

• Models with nominal rates from 9 ml/second to 21 l/second
• Natural frequency 20 Hz
• Low dead space
• Appropriate 4V heating power supply available

Harvard-HSE PTM Transducer

Pneumotachometers made of transparent perspex, especially designed for isolated lung preps or acute tracheomtomy in rats, guinea pigs and mice.

• Very low dead space
• Calibration nominal - experimental calibration by volume injection & flow integration
• Heating not required due to low thermal conductivity of the perspex
• Transparency helps maintenance of cleanliness

Differential Pressure Transducers

Designed for pneumotachography but also applicable to any low pressure measurements in respiratory physiology & mechanics.

• Three models - ±5.6 to ±22.5 mm water
• Require AC excitation (5 V rms max, 3-5 kHz) - see amplifier below
• Output nominally 20 mV/V FS (at 5 V excitation)
• Low displacement: 0.057 ml at FS deflection
• Replacement diaphragms available (allowing range changing)

Sine Wave Carrier Demodulator

This unit provides excitation to variable reluctance transducers such as the differential pressure transducers shown above, and demodulates the resulting output to a give a DC signal.

• Transducer excitation 5V rms, 5 kHz
• Provides ±10 VDC output (for transducers with > 15 mV/V sensitivity)
• Includes active filter, with response DC - 1 kHz (±10%)
• Ten-turn locking controls for zero and span

Carrier Frequency Adaptor

This Harvard-HSE adaptor box allows the interconnection of a capacitive or inductive transducer, and in particular the differential pressure transducers shown above, to a standard DC bridge amplifier (such as the BIOPAC DA-100).

The adaptor is powered by the bridge amplifier, and in turn provides 5 kHz sine wave excitation to the transducer. The returning transducer signal is demodulated and passed to the DC bridge amplifier.

PULMODYN Software

This 16-channel data acquisition software is specifically designed for respiration studies, in-vivo or in-vitro.

• Derives and presents the standard parameters for respiratory studies.
• Uses DT301 PCI acquisition board; Windows compatible
• Easy but versatile calibration and scaling
• Data acquisition and replay modes
• Event markers and concentration information
• Data exportable to spreadsheets and other software
• PENNOCK extension available for airway resistance calculations

Harvard Single Chamber Plethysmograph

This single-chamber plethymograph for anaesthetised rodents allows measurement of airway resistance and compliance without surgical intervention.

• Plethysmography chamber allows measurement of respiratory flow
• Oesophageal and tracheal cannulae used for pressure measurements

Harvard Double Chamber Plethysmograph

This plethysmography box is designed to allow measurement of respiratory flow and resistance in the conscious animal.

• Soft diaphragm separates the chambers
• Nasal flow is measured in one chamber; thoracic flow in the other
• Specific airway resistance may be calculated from the flow phase shift (see the PENNOCK option for PULMODYN software on our Pneumotachometer page)

HSE-Harvard Differential Transducer

This differential transducer is ideal for measuring oesophageal pressure using an air-filled catheter.