Chest Wall Kinematics Using Triangular Cosserat Point Elements in Healthy and Neuromuscular Subjects

Area of Science:

• Biomechanics
• Medical Imaging
• Respiratory Physiology

Background:

• Optoelectronic plethysmography (OEP) noninvasively measures chest wall (CW) motion for lung volume assessment.
• Current OEP analysis primarily focuses on global volume changes, potentially missing localized kinematic information.

Purpose of the Study:

• To introduce and validate a novel method for analyzing local CW kinematics using triangular Cosserat point elements (TCPEs) from OEP data.
• To assess the added value of TCPE analysis compared to traditional volume-based methods in healthy and patient populations.

Main Methods:

• A mesh of 78 triangles was created on the anterior CW using 52 markers, with each triangle represented by a TCPE.
• TCPE kinematics were described by four time-variant parameters, and CW volume contributions of six compartments were estimated.
• The method was validated in healthy subjects and patients with Pompe disease and Duchenne muscular dystrophy (DMD) during spontaneous breathing (SB) and vital capacity (VC) maneuvers.

Main Results:

• TCPE outward translation parameters correlated well with compartmental volumes in healthy subjects.
• In neuromuscular patients, TCPE analysis identified local asynchronous and paradoxical CW movements not discernible by volume changes alone.
• Phase angles (SB) and correlation coefficients (VC) demonstrated the enhanced sensitivity of the TCPE method.

Conclusions:

• The TCPE approach provides a more detailed analysis of local CW kinematics than traditional OEP volume measurements.
• This method offers additional, valuable information for the clinical evaluation of respiratory mechanics, particularly in patients with neuromuscular disorders.
• TCPE analysis has the potential to enhance the diagnostic capabilities of OEP in clinical settings.