The Inspired Sinewave Technique: A Comparison Study With Body Plethysmography in Healthy Volunteers

Phan, Phi Anh; Zhang, Cathy; Geer, Daniel E.; Formenti, Federico; Hahn, C.E.W.; Farmery, Andrew D.

doi:10.1109/jtehm.2017.2732946

Cited by 5 publications

(4 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The IST does not require special, forced manoeuvres, which patients often find challenging and uncomfortable. In an assessment of comfort (n = 18), 78% of participants selected the IST as their preferred test comparing to spirometry and body plethysmography 26 . The ability of IST to measure ventilatory heterogeneity could improve the impact of the IST when used as a diagnostic tool.…”

Section: Discussionmentioning

confidence: 99%

Simulation-based optimisation to quantify heterogeneity of specific ventilation and perfusion in the lung by the Inspired Sinewave Test

Trân

Nguyen

Bruce

et al. 2021

Sci Rep

View full text Add to dashboard Cite

The degree of specific ventilatory heterogeneity (spatial unevenness of ventilation) of the lung is a useful marker of early structural lung changes which has the potential to detect early-onset disease. The Inspired Sinewave Test (IST) is an established noninvasive ‘gas-distribution’ type of respiratory test capable of measuring the cardiopulmonary parameters. We developed a simulation-based optimisation for the IST, with a simulation of a realistic heterogeneous lung, namely a lognormal distribution of spatial ventilation and perfusion. We tested this method in datasets from 13 anaesthetised pigs (pre and post-lung injury) and 104 human subjects (32 healthy and 72 COPD subjects). The 72 COPD subjects were classified into four COPD phenotypes based on ‘GOLD’ classification. This method allowed IST to identify and quantify heterogeneity of both ventilation and perfusion, permitting diagnostic distinction between health and disease states. In healthy volunteers, we show a linear relationship between the ventilatory heterogeneity versus age ($${R}^{2}=0.42$$ R 2 = 0.42 ). In a mechanically ventilated pig, IST ventilatory heterogeneity in noninjured and injured lungs was significantly different (p < 0.0001). Additionally, measured indices could accurately identify patients with COPD (area under the receiver operating characteristic curve is 0.76, p < 0.0001). The IST also could distinguish different phenotypes of COPD with 73% agreement with spirometry.

show abstract

Section: Discussionmentioning

confidence: 99%

Simulation-based optimisation to quantify heterogeneity of specific ventilation and perfusion in the lung by the Inspired Sinewave Test

Trân

Nguyen

Bruce

et al. 2021

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Measurements of the first three parameters have been validated elsewhere [6], [10]- [12]. IST uses available components commonly used in anaesthetic/intensive care practice and has proven efficacy in spontaneously ventilating healthy volunteers [13]. Lung heterogeneity measured by the IST was first introduced and conceptualised by Tran et al [14].…”

Section: Introductionmentioning

confidence: 99%

Validating the Inspired Sinewave Technique to Measure Lung Heterogeneity Compared to Atelectasis & Over-Distended Volume in Computed Tomography Images

Trân

Phan

Crockett

et al. 2021

ICASSP 2021 - 2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

Self Cite

View full text Add to dashboard Cite

The inspired sinewave technique (IST) is a non-invasive nonionising method which can measure accurately lung parameters. Six anaesthetised pigs were studied after surfactant depletion by saline-lavage. Paired measurements of lung heterogeneity were taken with the IST and computed tomography (CT). Lung heterogeneity measured by the IST was calculated by the ratio of tracer gas outputs measured at 180s and 60s. In CT images, lungs were manually segmented and divided into different regions according to voxel density. The IST and CT show strong agreement on lung heterogeneity measurements. In the IST ventilation heterogeneity value, the linear correlation in total of six pigs are weaker than individual animal (R 2 =0.33 vs R 2 =0.67 on average). The IST perfusion heterogeneity agreements are lower than IST ventilation values due to the IST technical setup. IST has the potential to measure the lung heterogeneity in ARDS animals.

show abstract

“…The IST applies a forced oscillation of a low dose of N 2 O tracer gas with a sinusoidal period which can be determined by the user. The results of the IST provide lung function parameters including deadspace volume (VD), effective lung volume (ELV) and pulmonary blood flow (Q p ) (Phan et al 2017b, Bruce et al 2018, Clifton et al 2013. The IST results, including VD and ELV, provide suggestions for optimizing the ventilator setting.…”

Section: Introductionmentioning

confidence: 99%

Lung heterogeneity and deadspace volume in animals with acute respiratory distress syndrome using the inspired sinewave test

et al. 2020

Self Cite

View full text Add to dashboard Cite

Acute respiratory distress syndrome (ARDS) is associated with a high rate of morbidity and mortality, as patients undergoing mechanical ventilation are at risk of ventilator-induced lung injuries. Objective: To measure the lung heterogeneity and deadspace volume to find safer ventilator strategies. The ventilator settings could then offer homogeneous ventilation and theoretically equalize and reduce tidal strain/stress in the lung parenchyma. Approach: The inspired sinewave test (IST) is a non-invasive lung measurement tool which does not require cooperation from the patient. The IST can measure the effective lung volume, pulmonary blood flow and deadspace volume. We developed a computational simulation of the cardiopulmonary system to allow lung heterogeneity to be quantified using data solely derived from the IST. Then, the method to quantify lung heterogeneity using two IST tracer gas frequencies (180 and 60 s) was introduced and used in lung simulations and animal models. Thirteen anaesthetized pigs were studied with the IST both before and after experimental lung injury (saline-lavage ARDS model). The deadspace volume was compared between the IST and the SF6 washout method. Main results: The IST could measure lung heterogeneity using two tracer gas frequencies. Furthermore, the value of IST ventilation heterogeneity in ARDS lungs was higher than in control lungs at a positive end-expiratory pressure of 10 cmH2O (area under the curve = 0.85, p < 0.001 ). Values for the deadspace volume measured by the IST have a strong relationship with the measured values of SF6 (9 ml bias and limits of agreement from −79 to 57 ml in control animals). Significance: The IST technique has the potential for use in the identification of ventilation and perfusion heterogeneity during ventilator support.

show abstract

The Inspired Sinewave Technique: A Comparison Study With Body Plethysmography in Healthy Volunteers

Cited by 5 publications

References 27 publications

Simulation-based optimisation to quantify heterogeneity of specific ventilation and perfusion in the lung by the Inspired Sinewave Test

Simulation-based optimisation to quantify heterogeneity of specific ventilation and perfusion in the lung by the Inspired Sinewave Test

Validating the Inspired Sinewave Technique to Measure Lung Heterogeneity Compared to Atelectasis & Over-Distended Volume in Computed Tomography Images

Lung heterogeneity and deadspace volume in animals with acute respiratory distress syndrome using the inspired sinewave test

Contact Info

Product

Resources

About