IPL-1 Core Isolated Perfused Lung System for Mouse

The IPL-1 is an isolated organ perfusion system specifically engineered for the fragile mouse lung. The basic system can easily be upgraded to add capability modules for virtually any ex vivo pulmonary experiment.

The IPL-1 is specially designed for mouse lungs. Due to the fragile nature of the mouse lung, its suspension from the tracheal and vascular cannulae is difficult to accomplish without the rapid occurance of edema. In collaboration with experts in pulmonary physiology, an alternative design was implemented which allows for ventilation and perfusion with the lungs remaining in situ at a slight incline. This novel approach simplifies cannulation of the pulmonary artery and left atrium of the heart and dramatically reduces edema formation.

Advanced Engineering
Features & Benefits
Applications
Measured Signals & Calculated Parameters
Included items
Additional Requirements for a Functional Unit
Additional Components
Options and Upgrades

Advanced Engineering

Due to the fragile nature of the mouse lung, its suspension from the tracheal and vascular cannulae is difficult to accomplish without the rapid occurrence of edema. In collaboration with experts in pulmonary physiology, a design was developed which allows for ventilation and perfusion with the lungs remaining in situ at a slight incline in the open thorax.. This novel approach simplifies cannulation of the pulmonary artery and left atrium of the heart and dramatically reduces edema formation.

Most of the studies with isolated perfused lungs have been performed with lungs obtained from rats, guinea pigs, rabbits or dogs. The interaction of the immune system with the lung is currently an area of great interest. The mouse is the best characterized rodent species with respect to its immune system. Immunologic probes such as antibodies and cytokines are more widely available for mice versus other species. To facilitate studies on the interaction of the lung and the immune system, an apparatus for perfusing and ventilating mouse lungs has been developed. This apparatus is also suitable for studying the respiratory system of knock-out mice.

Ventilation 

The isolated mouse lung can be ventilated under positive pressure and under subatmospheric pressure to mimic the in vivo situation as closely as possible. There are bigger differences in vascular flows seen between positive and negative ventilation. Depending on the study, a ventilated lung or a physiologic breathing lung can be simulated. The lung is placed in the artificial thoracic chamber and ventilated at positive or negative pressure. It is connected through the tracheal cannula to the pneumotachometer for measurement of respiratory flow. The respiration rate, the inspiratory and the end-expiratory pressure can be adjusted by separate controls. (Positive ventilation using a regular Minivent ventilator is also possible). The surgery is always performed under positive ventilation to avoid that the lung collapses. Switching over to negative ventilation only requires you to close the chambers lid and switch over a stopcock. Switching back to positive ventilation is always possible. So the lung will never collapse./p>

Perfusion 

The pulmonary artery is cannulated to provide perfusion. The perfusate is passed by means of a roller pump at constant flow through the heat exchanger, through a bubble trap to the pulmonary artery and finally into the lung vascular bed. The perfusate outflow is usually provided by cannulating the left atrium of the heart. The heart remains on the lung and allows easier cannulation but is out of function.

The IPL-1 core system contains virually everything you need to accomplish the basic perfusion and ventilation experiments, requiring only the addition of core options for ventillation. Application-specific upgrades and options are also available.

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Features & Benefits

• Exclusive artificial thorax chamber for isolated lung with integrated changeover system—quick switch between simple positive-pressure ventilation and physiological negative (subatmospheric pressure) ventilation
• Integrated surgery table—reduces damage during preparation
• Pressure-balancing vessel—eliminates transmural pressure difference during sub-atmospheric ventilation—allows for simulation of hypertensive cardiac afterload
• Built-in, warmed pneumotachometer—minimal dead space volume
• Low flow resistance and dead space volume—minimize perfusion artifacts
• Milled infusion and pressure measurement paths—allow access to closed chamber
• Built-in humidifier frit—prevents lung drying
• Moist lung chamber has access ports for additional measurements or other sensors
• Simple add-on aerosol nebulizer
• Multi-gas for hyperoxic, hypercapnic, anesthetic or other alternative gas studies
• Drug injection pathway built directly into pulmonary perfusate stream
• Cannulae are matched to size of mouse vessel and feature tip occlusion protectors and mini ball system which allow cannulae to be fixed—further reduces incidence of vascular occlusion

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Applications

• Investigation of ventilation and perfusion in the isolated mouse lung 
• Continuous measurement of respiratory mechanics (tidal volume, airway resistance, dynamic compliance) and perfusate characteristics (pressure, lung vascular resistance, pO₂, pH)

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Measured Signals and Calculated Parameters

• Pulmonary Artery (Perfusion) Pressure
• Perfusion Flow
• Intrapleural (artificial thorax) Pressure or Tracheal Pressure
• Respiratory Flow

The following parameters are calculated from the raw data:

• Tidal Volume, Minute Volume
• Respiratory Volume
• Peak Inspiratory & Expiratory Airflow
• Vascular Resistance
• Respiration Rate
• Inspiratory Time & Expiratory Time
• End Inspiratory & Expiratory Pressure
• Dynamic Airway Resistance & Compliance

* Calculations are automatic when PULMODYN data acquisition software is used.

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Included Items

The basic unit includes: temperature-controlled negative pressure lung chamber (artificial thorax) with cover including venturi jet, positive pressure ventilation head, air humidifier, pneumotachometer, connectors to interface with the perfusion system, pressure equilibration vessel for venous flow and all necessary accessories (tracheal cannulae, pulmonary artery cannulae, left atrium cannulae)

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Additional Requirements for a Functional Unit

Negative Pressure Ventilation

For a functional unit, the core system requires the addition of one of these options (see table below) when performing both standard position- and negative-pressure ventilation studies: VCMP or VCMR-1

• VCM modules control the ventilation of the isolated lung preparation. They allow for the physiological negative pressure ventilation of the lung and positive ventilation during preparation.
  • 30 to 100 breaths per minute
  • I:E ratio can be set between 10 and 90% in 10% steps
  • End-inspiratory, end-expiratory, sigh and negative pressures can be individually set
• The TCM Timer Counter Module allows periodic sigh (hyperinflation) breaths to minimize edema formation

• The Pressure-Free Gas Supply Adapter (73-2789) is included with VCMR-1 (73-4293) but can be added to VCMP (73-4279) when delivering alternative gases during negative pressure ventilation. The adapter is used to supply the trachea with a gas mixture different from room air during negative ventilation including a needle valve to adjust gas flow.

* Negative pressure ventilation with a pressure regulator (73-4293) requires a pressurized gas supply from a tank or house air in the range of 2 to 8 bar (29 to 116 PSI)

Positive Pressure Ventilation

Choose the PPV-1 option when only positive pressure ventilation is desired.

• Ventilation rate from 60 to 400 breaths per minute
• Stroke volume 30 to 350 µl, simple adjustment while running
• Compact size allows positioning close to system for minimal system volume
• Valveless piston will not clog, easy to clean

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Additional Components

Cannula

Mouse cannulae for trachea, pulmonary artery and left atrium for use with the IPL-1 System

PULMODYN Data Acquisition Software

Online evaluation of a wide range of signals and classical respiration parameters.

Aerosol Nebulizer Kit 

• Low particle sizes (100% of the particles are below 10 µm)
• No Solution Warming Required
• Recommended for Nebulizing Drugs Sensitive to Ultrasonics
• Aerosol is Automatically Transported by Compressed Air at a Pressure of 1.5 bar (22 PSI)

Includes:

• Aerosol nebulizer with multi-gas adapter kit (73-3433)
• Pressure-free gas supply adapter for alternative gas supply for IPL-1 (73-2789)

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Options & Upgrades

Continuous Measurement of  pO₂, pH and pCO₂

The Universal Perfusion Solution Monitor permits precise continuous or discontinuous measurement in liquid media or perfusate of these three key parameters: pO₂, pH and pCO₂.

Drug Addition

These options for drug addition can be added to any isolated organ system where flow is measured or calculated and a drug must be added in a certain ratio.

Temperature Measurement

Measure perfusate temperature in any isolated perfused organ system

Deoxygenation

For deoxygenation of blood or buffers containing proteins (e.g. albumin) or erythrocytes

pH Control

Delivers CO₂ to maintain pH when system is not deoxygenated with N₂/CO₂ gas mixture

Venous Pressure Measurement

Venous pressure transducer and amplifier for venous pressure measurement in an isolated perfused lung system

Aerosol Nebulizer

Delivers an alternative gas supply to IPL-1 with option VCMP. Puchase with alternative gas supply PRGS-1