Buxco^® Non-Invasive Airway Mechanics

NAM Derived Parameters

• View List or NAM Derived Parameters

  Parameter	Description	Units
  f	Frequency - The instantaneous, breath-by-breath rate of breathing	BPM
  TV	Tidal Volume - The inspired volume of air per breath. The integral of the negative section of the flow curve	mL
  MV	Minute Volume - The product of the tidal volume and the respiratory rate, calculated on a breath-by-breath basis	mL/min
  sRaw	Specific Airway Resistance - The airway resistance times the thoracic gas volume. sRaw = (Pbaro-PP H2O@Body Temp)*dT Where Pbaro = Barometric Pressure PPH2O at Body Temp = Partial Pressure of H2O at Body Temp	cmH2O*sec
  sGaw	Specific Airway Conductance - The inverse of the airway resistance times the thoracic gas volume. SGaw – 1/(Sraw)	1/(cmH2O*sec)
  FRC	Functional Residual Capacity - The thoracic gas volume at the end of expiration derived using a model based on Boyle’s Law	mL
  R2	Goodness of fit statistic. A value from 0 to 1 which describes how well the flow data fits the Boyle’s Law model	N/A
  PIF	Peak Inspiratory Flow - The maximum inspiratory flow that occurs in one breath	mL/sec
  PEF	Peak Expiratory Flow - The maximum expiratory flow that occurs in one breath	mL/sec
  Ti	Inspiratory Time - The time spent inhaling during each breath, from the start of inspiration to the end of inspiration (determined by interpolation of start of expiration). The time flow is Negative.	Sec
  Te	Expiratory Time - The time spent exhaling during each breath, from start of expiration to end of expiration (determined by interpolation back to zero). The time flow is positive.	Sec
  dT	Delta Time - The time delay from the thoracic to the nasal flow signals taken at zero crossing points	ms
  Rpef	A ratio. Rate of achieving peak expiratory flow [Rpef = (time from Start of Expiration to PEF)/Te]. This has been used as an indicator of bronchoconstriction	N/A
  EF50	The flow at the point 50% of TV is expired. An indicator of bronchoconstriction	mL/sec
  Rinx	Rejection Index - Calculates the percentage of breaths rejected	%