Chest Wall Motion Analysis in Disease

Overview

Breathing movements, called chest wall motion, are very complex. The investigators are studying how movement of the abdomen, ribs and diaphragm contribute to breathing and how this differs with different diseases in the chest. Breathing movements may help with diagnosis, assessment of severity or assessing the impact of treatments for chest conditions. The investigators are following people who have a chest disease, measuring their chest wall motion and comparing it to their diagnosis and and how their treatment works. Chest wall motion can be measured in different ways at rest and whilst exercising. Small stickers on the chest can be used to reflect infra red light or visible squares of light can be shone onto the chest without using stickers.

Optoelectronic plethysmography (OEP) is based on the analysis during breathing of the trajectories of a series of markers positioned on the thoracic-abdominal surface of the patient. The positions in space of these markers are recorded and processed with mathematical models and algorithms by a computing unit that can accurately measure not only volume variations of the whole thoracic-abdominal wall, but also the variations of the various compartments. This detects, for example, asymmetries in the action of respiratory muscles. The system can accurately measure current volume, vital capacity, respiratory frequency, duration of the phases of inspiration and exhalation, the average inspiration and exhalation flux and the volume variations at the end of exhalation. Structured Light Plethysmography (SLP) also assesses regional chest wall excursion but does not require markers to be placed on the patient. The system uses visible light shone onto the chest wall in a checkerboard pattern and reflected back by the patient's skin or a tight T shirt. Images from 4 Microsoft Kinnect Motion Cameras can be used to create a 3D representation of the patient's torso. This system has been shown to correlate well with chest wall measurements recorded by OEP. These systems are innovative examination instruments, non-invasive, accurate, easy to use and unlike traditional plethysmographic technologies, are not affected by humidity and temperature variations and can easily be used to perform measurements for extended periods of time. They accurately measure the dynamics of the volume variations that occur during breathing in the various sections of the thoracic-abdominal walls (upper, lower and abdominal thoracic area). This data, which is otherwise undetectable, is a useful contribution to the evaluation of patients. We will apply chest wall motion analysis to understanding the physiology of thoracic disease processes as well as assessing potential diagnostic and prognostic (response to treatment) markers that could be used in future clinical practice.