The latest release of flexiWare (8.2) brings with it the capacity to assess both work of breathing (WOB) and airway compliance, expanding the comprehensive array of pulmonary assessments possible with the flexiVent system.
WOB is the amount of energy required overcome the elastic and resistive qualities of the respiratory system; thereby producing tidal ventilation. It can be calculated as the product of pressure and volume (a unit of work).
The WOB parameter now incorporated into flexiWare originated from a publication from Dr. Jonathan Phillips (Amgen), where WOB was calculated as the integral of the inspiratory limb of the pressure volume loop (lower branch), plotted against volume (see the below reference for more information).
SCIREQ worked to incorporate this WOB parameter into flexiWare, where we calculate:
The additional parameter of airway compliance (Caw) is also now available with flexiWare 8.2. This parameter is calculated from the initial inflation limb of the full-range PV curve (Lung Volume maneuver only), which occurs after lung degassing. Following lung collapse the lungs are inflated, in the portion of the curve before the lungs re-open the slope of the pressure volume relationship represents the airway tree distension (airway compliance Caw) (see fig. 1).
Figure 1: A full range pressure volume loop output from flexiWare showing compliance (C), opening pressure (Pop) and airway compliance (Caw).
For more information on Caw, please refer to the recent publication (below) which assessed airway compliance in mouse models of obstructive and restrictive respiratory diseases along with the work of breathing, a parameter susceptible to move with changes in Caw.
For more information on the above parameters or how to access flexiWare 8.2 please contact [email protected].
Welcome to SCIREQ’s knowledge center. You can find everything from software registration to document downloads to complete list of SCIREQ publications in this section. Everything you need to get the most out of your SCIREQ system.