Monday, March 19, 2018

A step in moving towards the low frequency range

In clinical medicine, spirometry continues to dominate as the pulmonary function test of choice. This is despite the issues which limit its utility, largely patient compliance and the limited inferences which can be made regarding the mechanical properties of the respiratory system. Alternatively, the forced oscillation technique (FOT), utilized by the flexiVent preclinically, is well-known for its rich description of the mechanical properties of the respiratory system. However, despite becoming the gold-standard in preclinical research, the approach has yet to make significant in-roads into the clinical domain, especially in the low frequency range (0-2 Hz) that gives access to the peripheral lung, the area most sensitive to pathological changes.

In ventilated patients FOT solutions do exist, however free-breathing patients present obstacles as accurate measurements of the respiratory system rely on precise measurements of pressure and flow. Potential solutions to this problem have been trialed, for instance training patients to perform voluntary apnea1 or by triggering an apneic event in infants using the Hering-Breuer reflex2.

A recent doctoral thesis by Dr. Hannes Maes, under the supervision of Prof. Gerd Vandersteen at Vrije Universiteit Brussel (Free University of Brussels), titled, Low Frequency Forced Oscillation Technique in Clinical Practice, proposes an innovative solution to overcome confounding breathing frequencies, as well as a comprehensive review of the field3.

Dr. Maes presents a novel fan-based setup specifically designed for FOT measurements between 0-5 Hz in free-breathing subjects1 Pressure signals (multi-sine wave) are superimposed on the patients normal tidal breathing by controlling two fans (one pushing and one pulling air). Compensatory signals are also applied to the fans to ensure a predefined power spectrum and to suppress the nonlinear influences of the equipment or the subject’s breathing, along with post-measurement modeling techniques.

Schematic of fan-based FOT measurement device for free-breathing subjects

Results from a clinical trial on 60 subjects, that included healthy individuals as well as asthmatic and COPD patients, are also presented and, in the end, Dr. Maes offers a new framework for the time-varying behavior of the respiratory system during spontaneous breathing.

We congratulate Dr. Maes on this achievement and very interesting approach. This elegant work contributes towards the advances required to ultimately enable routine provision of the low-frequency FOT in patient populations and for clinicians to benefit from its diagnostic capacity.

For more information on the work of Dr. Maes and access to the full manuscript, please click here.

1. Hantos, Z., Daróczy, B., Suki, B., Galgóczy, G. & Csendes, T. Forced oscillatory impedance of the respiratory system at low frequencies. J. Appl. Physiol. 60, 123–32 (1986).
2. Hall, G. L., Hantos, Z., Wildhaber, J. H. & Sly, P. D. Contribution of nasal pathways to low frequency respiratory impedance in infants. Thorax 57, 396–9 (2002).
3. Maes, H. Low Frequency Forced Oscillation Technique in Clinical Practice. (Vrije Universiteit Brussel, Belgium, 2017).

Monday, March 5, 2018


Many novel inhaled compounds and drugs require dry powder delivery and preclinical testing to assess efficacy and safety. The inExpose is an inhalation exposure system that provides a small-scale, configurable exposure for mice and rats studies.

Our recent addition of dry powder delivery expands the range of exposure environments beyond cigarette smoke, electronic cigarette vape, aerosols and gases.

The dry powder integration with the inExpose features:
          »   Up to 4 towers or chamber to be exposed simultaneously
          »   Identical or varying levels of exposure per tower or chamber
          »   Existing automation and control
          »   Small- scale exposure, minimizing compound use

Will you be attending the Society of Toxicology meeting in San Antonio next week? If so, I would like to invite you to come by booth #1545 to see our solutions for your preclinical respiratory research. We will be presenting a range of precise preclinical physiology solutions for safety pharmacology and toxicology studies, including:

          »   Automated, small-scale inhalation exposure studies featuring
               cigarettes, e-cigarettes, dry powders and aerosols
          »   Non-invasive tracking of ventilatory patterns and controlled gas exposure 
               with whole body plethysmography
          »   Continuous monitoring of physiological parameters with implantable and
               jacketed telemetry

Exhibit hours - Booth 1545
          Monday March 12 9:15am to 4:30pm
          Tuesday March 13 9:15am to 4:30pm
          Wednesday March 14         9:15am to 4:30pm

Click here to set-up a meeting to learn more about our solutions for your safety pharmacology and toxicology studies. 

If you are not planning to attend the conference but would like to receive additional information about our respiratory equipment, please contact our team of application specialists.

Looking forward to seeing you in San Antonio!

Monday, February 26, 2018

flexiVent User Group Meeting - April 26, 218 in San Diego

Join us for a day of scientific presentations and discussions to learn more about the flexiVent’s capabilities & applications and share your feedback with other users. 

WHEN?        Thursday April 26, 2018
                       Following the Experimental Biology Conference 2018

WHERE?      San Diego, California (Hilton San Diego Bayfront)

AGENDA:      » Presentation & Demo by our flexiVent Experts
                       » Case Studies & Interactive Session
                       » User Presentation: Learn how others use the flexiVent
                       » Recent Developments and a chance to ask your questions

Final Agenda and Details coming soon!  Space is limited, please CLICK HERE to register and be part of this event.

If you are interested in presenting your pulmonary research work during this user group, do not hesitate to contact us as soon as possible, to include your presentation in the agenda.

Please note that this user group meeting will be free of charge.

If you have any questions, do not hesitate to contact us at or toll-free at 1-877-572-4737.

We look forward to seeing you in San Diego!

Best regards,
Your SCIREQ Team

Wednesday, February 21, 2018

SCIREQ at AAAAI & WAO Joint Congress in Orlando

Will we see you at the American Academy of Allergy Asthma & Immunology (AAAAI) conference in Orlando, next week? This congress is a wonderful opportunity to convene with other world-class researchers to discuss the latest discoveries in asthma and inflammatory diseases.

Mouse models have been and continue to be of invaluable importance in asthma research, for the elucidation of key disease pathways as well as in the assessment of potential therapies as highlighted in recent articles.

SCIREQ enables scientists to measure detailed lung function outcomes utilizing the flexiVent, which has become the gold-standard for in vivo respiratory research.

Join us at booth 229 to learn more.                                   

Exhibit Hours
Saturday, March 3:   9:45am – 3:15pm
Sunday, March 4:     9:45am – 3:15pm
Monday, March 5:  9:45am – 2pm

»      Click here to set-up a meeting with our specialists during or after the symposium.
»      Click here to view the AAAAI & WAO Joint Congress details.

If you are not planning to attend the conference but would like to receive additional information about our respiratory equipment, please contact our team of application specialists.

Monday, February 19, 2018

Upgrade to flexiWare 8.0

We are happy to announce the release of flexiWare 8.0!  This latest version is unified software for both the flexiVent and inExpose systems and flexiWare 8.0 includes features such as:


  • Official release of the Lung Volumes maneuver along with its associated tasks and outcomes!
  • Diagnostic & power-on Self-Test available, allowing for greater confidence in the system and easier troubleshooting.
  • Significantly reduced time to load and view data in review mode (retroactively available for previously collected data as well).
  • Pop-up now appears on screen to notify users of excluded datasets as they occur to allow for immediate action.
  • Ability to copy subjects when creating new subjects or studies.


  • System leak test available with easy to follow software wizard to ensure the system is leak free prior to beginning an experimentation session.
  • Ability to reinitialize and modify CSR setting anytime during an experimentation session.
  • Significantly improved and integrated profile editor, including the ability to view pump and nebulizer trigger signals in real-time.
  • Scripting capabilities added for complex protocols as well as for improved standardization.
  • Ability to create export scenarios for easier data export.

Ready to upgrade?

Contact us to find out if you are eligible for a free upgrade and how to have flexiWare 8.0 running in your lab!

Phone: 1.514.286.1429
Toll Free: 1.877.572.4737

Monday, January 22, 2018

Refined Study Design with Spirometry

Spirometry is a widely known clinical pulmonary test measuring volumes and flows expired by patients that is used to confirm a diagnostic of respiratory disease or follow treatment. SCIREQ’s flexiVent’s offers an analogous test for preclinical research with its Negative Pressure Forced Expiration (NPFE) extension. By exposing the subject’s airway opening to a negative pressure to rapidly draw out air from the lungs, the system can generate flow-volume loops or volume-time plots, from which the flexiWare software can then extract clinically relevant volume and flow parameters (e.g. FEVx, FEFx, FVC, PEF).

A recent publication by Devos et al.1 characterized forced expiration measurements in some well-established mouse models of lung diseases, which specific phenotypes were confirmed by a concomitant respiratory mechanics assessment. The researchers observed that disease-induced changes in forced expiration-related charts and parameters were generally similar to what was observed in the clinic. For example, when compared to a control group of healthy mice.

  • Mice with fibrosis exhibited a typical restrictive profile, with a reduced PEF & FVC and a normal FEV0.1/FVC ratio. 
  • Mice with emphysema displayed a decrease in PEF characteristic of an obstructive phenotype.
  • Mice presenting an acute lung injury had significantly reduced PEF.
  • Mice with features of asthma showed a decrease in FEV0.1 following methacholine challenges.

SCIREQ’s flexiVent is the first platform that allows forced expiratory manoeuvres to be performed side-by-side with respiratory mechanics, pressure-volume loops, or lung volume measurements in mice and rats. This unique feature enables a refined study design with outcomes susceptible to translate between preclinical research and clinical settings. 

Read more
1Devos, FC et al. 2017. Forced expiration measurements in mouse models of obstructive and restrictive lung diseases. Respiratory Research 18: 123.

Leaving Nothing Out

The functional residual capacity (FRC) plays an important role in maintaining optimal ventilation.  FRC is a subdivision of the total lung capacity (TLC) and represents the volume of air left in the lungs at the end of an expiration.  It is involved in keeping the small airways open for an efficient gas transfer between the air and the blood.  Variations in that volume can be seen under several physiological or pathophysiological conditions and can be associated with clinical symptoms like dyspnea. 

FRC is a clinically important parameter which is determined, along with other lung volumes/capacities, when performing a full lung function assessment.  It is inversely related to airway resistance, such that a reduction in FRC will increase the level of opposition to airflow.  At the preclinical level, while measurements of airway resistance are routinely performed in many research laboratories, the determination of FRC is rarely reported as it can prove to be technically challenging, especially in subjects as small as mice.  

It is possible to obtain FRC from a full-range pressure-volume (PV) curve.  This was done until now in mice by determining the volume at a conventionally or arbitrarily defined equilibrium pressure (e.g. 0 cmH20), since FRC represents the volume at rest.  In a recent report1, FRC was estimated by a novel approach in rodents, following the automation of the full-range PV curve technique with SCIREQ’s flexiVent system.  It was estimated by volume subtraction and took advantage of the access to varied, precisely controlled, automated maneuvers within a single device.  In comparison to the previously established methodology, this novel approach demonstrated a more accurate estimation of FRC, particularly in diseased subjects.

The estimation of FRC by volume subtraction can be performed in rats and mice along with the determination of other lung volumes/capacities, measurements of respiratory mechanics, or partial PV curves.  The authors showed that the FRC estimate more than tripled in a mouse model of emphysema, representing the most important change in a panel of lung volumes/capacities.  Including measurements of FRC and other lung volumes/capacities in the characterization of respiratory models or novel therapeutic strategies can contribute to generate comprehensive and robust functional assessments. 

No model fully recapitulates human respiratory diseases.  Let’s reconsider the endpoints typically reported so that nothing that matters gets ignored.

Read more
1Robichaud, A et al. 2017. Automated full-range pressure-volume curves in mice and rats. Journal of Applied Physiology 123: 746-756.

Monday, January 8, 2018

Empower yourself

Attending a training such as the Phenotyping Mice Models of Human Lung Disease organized by the Jackson Laboratory is a great way to advance skillsets or simply get started in the field of respiratory research. It represents a wonderful opportunity for researchers of all stages to learn and network in a structured yet informal environment. The uniqueness of the event lies in the roundness of the approach, which combines theoretical sessions and practical experience in all topics.

SCIREQ has been a partner in this event for years now and has contributed with providing hands-on experience to participants with lung function measurements using the flexiVent alongside authorities in the field. Practical exercises are designed to demonstrate a response to a particular intervention, highlight unique measurements (including partitioning the lungs between airway and tissue effects), and analyze outcomes with respect to their physiological implications.

JAX Experiments
As an example, participants were guided during the last workshop to utilize pressure-volume loops to confirm the effects of an intervention with implications on lung surfactant and atelectasis.  
Figure 1: Pressure-volume loops from a subject before (left) and after (right) a lung lavage. The red line represents the Salazar-Knowles equation fit to the deflation limb of the pressure-volume curve.
They were also invited to examine the effect of increasing the positive end expiratory pressure (PEEP) during ventilation and lung function measurements while exploring the impact on detailed respiratory mechanics parameters before and after the intervention.

Airway responsiveness to a specific bronchoconstrictor agent before and after a therapeutic treatment or an assessment of various lung volumes are also typically part of the repertoire of techniques taught.  

Figure 2: Single (left) and broadband (right) forced oscillation outcomes prior to and following increasing doses of nebulised methacholine in presence or absence of a bronchodilator treatment.

Looking forward
The event runs every second year in Bar Harbor, Maine, and accepts a limited number of participants. Plan ahead to take part in the workshop, which we highly recommend to both senior researchers and students alike.