Which device is primarily used to measure chest wall displacement during respiration?

The strain belt is specifically designed to measure chest wall displacement during respiration. It works by detecting changes in the circumference of the thoracic area as the chest expands and contracts during the inhalation and exhalation phases of breathing. When placed around the chest, the belt provides valuable data on the dynamic movements associated with respiration, making it particularly useful in studies and assessments focused on respiratory mechanics.

In contrast, a pneumotachograph is primarily used to measure airflow and is not directly concerned with chest wall movement. An electronic transducer can measure various respiratory parameters but is more general and not specifically tied to displacement measurements of the chest wall. Intramuscular EMG assesses muscle activity and is unrelated to measuring chest wall displacement per se. Therefore, the strain belt stands out as the most suitable device for tracking and quantifying chest wall displacement during respiration.