A chest wall restrictor to study effects on pulmonary function and exercise. 1. Development and validation

Area of Science:

• Physiology
• Respiratory Mechanics
• Medical Device Design

Background:

• Chest wall restriction impedes lung expansion, impacting pulmonary function and exercise capacity.
• Conditions like scoliosis and occupational hazards (e.g., bulletproof vests) can cause chest wall restriction.
• Quantifiable and reproducible methods are needed to study chest wall restriction's effects.

Purpose of the Study:

• To describe a novel constant-pressure chest wall-restrictive device.
• To assess the device's ability to provide quantifiable and reproducible inspiratory loads.
• To evaluate the impact of the device on pulmonary function tests.

Main Methods:

• A constant-pressure chest wall-restrictive device was designed and utilized.
• Ten subjects performed pulmonary function tests (FVC, FEV1.0) under four increasing restrictive loads.
• Repeated-measures multivariate analysis of variance was used to analyze the data.

Main Results:

• Significant decreases in forced expiratory vital capacity (FVC) and forced expiratory volume in 1 second (FEV1.0) were observed with increasing loads.
• The ratio of FEV1.0 to FVC (FEV1.0%) remained consistent across loads.
• No significant differences were found based on time or body position (seated vs. standing).

Conclusions:

• The developed device effectively applies a quantifiable and reproducible inspiratory load.
• The device successfully mimics the pulmonary function decrements seen in restrictive lung diseases and occupational scenarios.
• This tool offers a valuable method for researching chest wall restriction's physiological impact.