Breathing training characterization by thermal imaging: a case study

Specific respiratory muscle training improves athletes' performance particularly at high intensities. This work aims to study the usability of infrared thermography to evaluate two types of breathing, thoracic and diaphragmatic, on the cartographies of the cutaneous temperature of the trunk. IR thermography is a non-invasive technique that visually represents the whole process during and after training. A well trained subject in both respirations performed the exercise with SpiroTiger® for 5 minutes, followed by 5 minutes of recovery. Ten Regions of Interest on the subject skin were selected following anatomical and functional correspondence with the muscles involved in breathing. In order to check functional behaviour of respiratory muscles, we calculated the correlation among thermal data of all the ROI. Global temperature of body trunk showed a general decrease of few degrees during both kinds of the training but thermal imaging documented also thermal spots of increasing temperature in pectoral areas due to the superficial vasocirculation in thoracic breathing. The results indicate that thermal imaging can be used for quantitative evaluation of the cutaneous temperature in various trunk zones characterized by thoracic and diaphragmatic breathing. This work can be considered a preliminary study to the development of future statistical study.