# Measuring lung mechanics in patients with COPD using the handheld portable rapid expiratory occlusion monitor (REOM): A cross‐sectional study

## TL;DR

A new handheld device called REOM was tested for measuring lung resistance in COPD patients and showed strong agreement with traditional methods.

## Contribution

The REOM device is introduced as a novel, portable alternative for measuring lung mechanics in COPD.

## Key findings

- REOM resistance measurements showed very strong correlation and agreement with conventional oscillometry in COPD patients.
- REOM successfully discriminated between mild and very severe COPD with high accuracy.
- User experience scores for REOM were excellent, indicating good usability and patient satisfaction.

## Abstract

While conventional spirometry is associated with strenuous “forced” maximal respiratory maneuvers and infection control implications, oscillometry is not associated with these issues. However, portability, convenience of use, and interpretation remain common limitations to both techniques. This study tested the concordance and agreement between resistance measurements obtained from the handheld portable REOM device (Reo‐f, Reo‐s) with those from conventional oscillometry (R19, R5) in PFT‐confirmed “mild” (GOLD 1) and “very severe” (GOLD 4) COPD. Unadjusted and adjusted concordance (Spearman correlation) and agreement (Bland–Altman tests) served as co‐primary outcomes. Discrimination between GOLD 1 and 4 COPD (Wilcoxon rank sum test, Support Vector Machine (SVM) classifier) and patient user experience (System Utility Scale (SUS), Participant Satisfaction Survey (PSS)) served as secondary outcomes. In 17 participants (GOLD 1 n = 9, GOLD 4 n = 8), adjusted R5‐Reo‐s (0.95 [0.81, 0.98]) and R19‐Reo‐f (0.93 [0.79, 0.99]) correlations were very strong, as was agreement (mean differences: −0.07, 0.08, respectively). Statistically significant between‐group differences were observed for all four resistance parameters. Reo‐s in particular exhibited perfect discrimination between GOLD 1 and 4 disease, with some minor misclassification by Reo‐f, R5 (n = 1 each) and R19 (n = 4). User experience scores were excellent. These results support the capacity for REOM as a novel, complementary diagnostic device in COPD.