At its core, the flexiVent is a computer-controlled, precision piston pump that can intersperse mechanical ventilation with a variety of volume and pressure controlled manoeuvres to obtain accurate, reproducible measurement of respiratory mechanics.
A basic flexiVent system includes the following:
Base unit: houses the motor, optical position sensor and electronics.
Module(s): interchangeable units, allowing a range of subjects to be studied.
flexiWare software: manages the collection, analysis, graphing and archiving of data.
Forced Expiration Extension (FEV)
EXPANDING THE MEASUREMENT RANGE.
The forced expiration extension (FEV) permits the generation of flow-volume loops and its associated parameters by rapidly exposing the subject’s airway opening to negative pressure, referred to as Negative Pressure Forced Expirations (NPFE). The flexiVent is the first platform that permits NPFEs concurrently with a wide variety of respiratory mechanics measurements in the same cohort of animals.
AVAILABLE FOR MICE AND RATS
The FEV extension readily connects to most existing flexiVent systems for use in mice and rats. It includes a plethysmograph chamber with an integrated sensor to measure chest flow, a negative pressure reservoir with its controller, and two additional valves. Upon completion of the NPFE, the flexiWare software immediately displays flow-volume loops and automatically calculates all pertinent volume and flow parameters (FEVx, FEFx, FVC, PEF).
TOWARDS CLINICAL STUDIES
The addition of FEV offers a means to more directly assess expiratory flow limitation. Although NPFE manoeuvres are obtained under conditions that differ substantially from clinical spirometry, they may provide a useful cross-species correlation for drug development studies.
- Shalaby KH et al. Combined forced oscillation and forced expiration measurements in mice for the assessment of airway hyperresponsiveness. Respir Res. 2010 Jun 21;11:82.
- Tanaka et al. Superiority of PC-SOD to other anti-COPD drugs for elastase-induced 2 emphysema and alteration in lung mechanics and respiratory function in mice. American Journal of Physiology Jun 2012
- Tibboel et al. Intravenous and Intratracheal Mesenchymal Stromal Cell Injection in a Mouse Model of Pulmonary Emphysema. Journal of COPD. Jul 2014
- HF Håkansson et al. Altered lung function relates to inflammation in an acute LPS mouse model. Pulmonary Phrmacology & therapeutics. Oct. 2012
- Kurotsu et al. – Ameliorative Effect of Mepenzolate Bromide against Pulmonary Fibrosis. Journal of Pharmacology. April 2014.
USING THE AERONEB.
The flexiVent can be tightly integrated with the Aeroneb ultrasonic nebulizer to deliver aerosols deep into the lungs. To add an Aeroneb to your flexiVent system, a suitable adapter is required that mounts into the module.
DELIVERING THE DOSE
flexiWare offers complete control over the timing of the challenge, the nebulization rate and the manner in which aerosolization is synchronized with ventilation. Furthermore, dose response curves can be automatically generated. The software estimates the dose delivered to the subject and can plot it against delivered dose or concentration, in addition to characterizing the losses due to rain-out.
OFFERING A HIGH QUALITY LUNG SCAN.
The flexiVent’s control and standardization of experimental conditions (e.g. respiratory rate, tidal volume, PEEP, volume history) is directly beneficial to the imaging application by eliminating motion artifacts. It offers the ability to compare and correlate structural information obtained from lung images with lung function data obtained directly from the flexiVent.
We offer turn-key packages to integrate with a variety of micro-CT scanners on the market. The package includes a custom gating cable, specialized accessories for connecting the subject through the scanner’s instrument channels, as well as other necessary connectors, adapters and flexiWare software templates.
HEART RATE. BLOOD PRESSURE. BODY TEMPERATURE.
Sensors to monitor the subject’s vital signs can easily be integrated with the flexiVent system. The EKG transducer monitors the subject’s heart rate by connecting to the subject’s limbs. The connection is ensured with the use of sub-cutaneous needles. The invasive saline-filled blood pressure transducer allows for observation of changes in blood pressure. Body temperature can be measured with the rectal sensor. Vital signs are displayed in the flexiWare software in real-time and may be recorded continuously or with every mechanics measurement.
ALL IN ONE SOLUTION.
While the flexiVent is typically utilized to assess the mechanical properties of the lower airways, it can also be used for accurate measurements of nasal obstruction. As previously reported, this approach provides a means to reliably and directly assess upper airway resistance in disease models.
Similar to respiratory mechanics measurements of the lower airways, the flexiVent uses the forced oscillation technique to deliver a small amplitude test signal to the upper airways. Nasal resistance is then derived by the operating software from the pressure-flow relationship as described in the single compartment model. At the moment, these measurements are described in allergic rhinitis pre-clinical research, one of the most common allergic diseases worldwide affecting people of all ages.
EVERYTHING YOU NEED IS INCLUDED.
SCIREQ will provide suitable accessories with the original purchase of your basic system or any of the extensions. Some items are considered disposable and will need to be replaced over time or after heavy use.
For the flexiVent, we offer calibration accessories such as pressure manometers, flow meters and test loads. Wetted components including the Aeroneb, cannulae, tubing, O-rings, valves and filters are available. Computers, cables, power supplies and tools may also be acquired as needed.