Thoracic Motion Analysis Using a TrueDepth Camera in Patients with Relapsing Polychondritis: A Pilot Study

Area of Science:

• Pulmonary Medicine
• Medical Technology

Background:

• Relapsing polychondritis (RP) is a rare autoimmune disease causing airway inflammation.
• Airway complications in RP, like stenosis, worsen prognosis.
• Spirometry may be impractical for RP patients with severe airway compromise or tracheostomy.

Purpose of the Study:

• To evaluate a smartphone application, DepthRecorder, for real-time thoracic motion analysis.
• To assess the correlation between DepthRecorder and standard spirometry in RP patients.

Main Methods:

• Twelve relapsing polychondritis patients underwent simultaneous spirometry and DepthRecorder assessment.
• Thoracic motion data from DepthRecorder were height-corrected.
• Spearman's rank correlation analyzed the relationship between DepthRecorder and spirometry (FVC, FEV1, FEV1/FVC).

Main Results:

• Uncorrected DepthRecorder showed moderate correlation with FEV1 and FEV1/FVC.
• Height-corrected data revealed stronger correlations: FVC (ρ=0.76), FEV1 (ρ=0.72), and FEV1/FVC (ρ=0.60).
• All correlations after correction were statistically significant (p < 0.001).

Conclusions:

• The height-corrected DepthRecorder application correlates strongly with spirometry.
• This technology offers a potential non-invasive respiratory assessment tool for RP patients.
• Further validation and establishment of clinical standards are necessary.