Inductive Plethysmography—A Facilitated Postural Calibration Technique for Rapid and Accurate Tidal Volume Determination in Low Birth Weight Premature Newborns^1,2

Abstract

Inductive plethysmography is a noninvasive method of measuring lung volumes in infants. This technique, however, has had very limited use in premature newborns because of the difficulty of calibrating the device with regard to the small tidal volumes (VT) in such infants. The present study describes a facilitated calibration of the inductive plethysmograph in low birth weight infants. The technique depends on generating significantly different compartmentalization of VT into rib cage and abdominal components by changing the infant's position from supine to upright. Linear regression analyses were performed to compare VT measurements made in 9 premature infants with the inductive plethysmograph and the pneumotachygraph; an overall Z-transformed correlation of 501 breath-to-breath comparisons yielded an r value of 0.80; the mean VT (pneumotachygraph) was 13.9 +/- 4.7 ml SD; the mean VT (inductive plethysmograph) was 14.3 +/- 5.1 ml SD. It is concluded that inductive plethysmography is an accurate method to measure VT in small premature infants. Moreover, the ease of the two-position technique for calibration of the device gives the inductive plethysmograph greater utility as a clinical and research tool for measuring lung volumes in premature infants.

Respiratory inductance plethysmography calibration for pediatric upper airway obstruction: an animal model

“…However, RIP signals must be calibrated for accurate values of flow. Some RIP calibration techniques require specific respiratory maneuvers to generate isovolume conditions (a period of effort with no air flow), while others can be applied to tidal breathing ( 9 , 10 ).…”

A device for 24 hour ambulatory monitoring of abdominal girth using inductive plethysmography

“…Inductive plethysmography (IP) has been extensively used in non-ambulatory settings for quantitative monitoring of respiration, with varying degrees of success. Researchers have variously found it to be a quantitative (Stefano et al 1986), non-quantitative (Ballard et al 1988) or most often a 'semiquantitative' (Caretti et al 1994) method for monitoring respiration. In almost all cases, calibration is performed in vivo against a standard measuring device, e.g., a spirometer.…”

Lung Volume Recruitment in Lambs during High-Frequency Oscillatory Ventilation Using Respiratory Inductive Plethysmography

“…The method employs thoracic and abdominal elastic bands that register changes in inductance proportional to changes in thoracic and abdominal volume. RIP has been used to measure tidal volume (TV) and minute ventilation and correlates well with pneumotachography in infants and children (31)(32)(33)(34). However, measurement of changes in lung volume by use of RIP has been limited by baseline drift and nonlinearity of the measurement at extremes of lung inflation (35).…”