Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Adult patient with chronic obstructive pulmonary disease (COPD), stage 3-4.
Healthy adult volunteer.
Exclusion criteria
Refusal to participate or withdrawal of consent.
Age < 18 years.
BMI > 35 kg/m².
Pregnancy or breastfeeding.
Inability to understand instructions or cooperate (cognitive impairment, language barrier).
Neurological condition affecting breathing (e.g., recent stroke, ALS, myopathy).
Thoracic condition limiting access to the intercostal muscles (e.g., major chest wall deformity, surgical scar).
Recent thoracic or abdominal surgery (< 3 months).
Known esophageal disease (stricture, achalasia, severe esophagitis, diverticulum, history of perforation).
ENT or tracheal abnormality preventing probe insertion (e.g., tumor, malformation, tracheostomy).
Swallowing disorders or risk of aspiration.
Recent exacerbation (< 6 weeks).
Oxygen therapy > 2 L/min during exertion.
Hemodynamic instability.
Not affiliated with a social security scheme.
Legally protected persons (as defined by law).
