Acoustic and Volumetric Measurements in Order to Objectify Bronchial Congestion in Patients With Obstructive Respiratory Pathologies Within the Framework of Their Management in Respiratory Physiotherapy for Decongestion

COPD is a chronic respiratory disease defined by permanent airway obstruction. Epidemiological data are scarce: the prevalence is difficult to estimate because of underdiagnosis and the difficultý to perform respiratory function tests (RFTs) in epidemiological studies. It is estimated at 7.5% in a population over 45 years of age, with the incidence appearing to stabilize in men and increase in women. Furthermore, in 2018, 25.4% of adult patients had daily tobacco use. In 2014, 81,600 individuals were on long-term disability (LTD) for chronic bronchitis without specifics. The 2017 report by the Directorate for Research, Studies, Evaluation and Statistics (DREES) on the health status of the population in France shows that: in 2013, approximately 19,000 deaths were related to COPD, 48% of which were due to the initial cause; the crude mortality rateś related to COPD were 96/100,000 adults aged 45 years or older in men and 41/100,000 in women ; in 2014, the annual number of hospitalizations for COPD exacerbation ranged from 100 000 to 160 000, depending on the indicator; crude hospitalization rates were 31/10 000 in men and 15.4/10 000 in women, with the highest rates (>20%) in the northern and eastern regions of France and in Reunion. Standardized hospitalization rates have increased́ since 2000, by 2% per year in men and 5% per year in women. The average direct costs of COPD increase with the level of severitý of the disease and rise on average from €7,628 per year for the least severe patients to €20,747 per year for patients on oxygen therapy.

In this condition, a large part of the muscular work is taken up by breathing (fight against bronchial, parietal or fibrous resistances of the lung tissue, decrease of the exchange surface), requiring physiotherapeutic management.

The physiotherapeutic treatment "respiratory rehabilitation", includes 4 items: respiratory physiotherapy for decongestion, muscular strengthening, improvement of endurance and therapeutic education. Within this framework, the techniques of de-cluttering are intended to decrease the hydrodynamic resistance of the bronchial tree. A systematic evaluation of the patient's condition is carried out by the practitioners to assess, at the time of the session, the bronchial congestion. In addition to their knowledge of the history of the patient they are following and the result of the oximetry measurement, practitioners rely on several indicators to assess the patient's bronchial congestion and define their therapeutic approach: cough, sputum, oximetry and peak expiratory flow, pulmonary auscultation which provides sound information, and a call maneuver which allows a subjective assessment of the volumes that can be mobilized thanks to haptic information.

Sound expertise remains delicate: even the most educated human auditory system is not physiologically capable of detecting some of the relevant information. Multiple pathological breath sounds are referenced in the literature, for which different classifications exist, based on their frequency characteristics, their sound waveforms and their durations.

As for the haptic evaluation of thoracic compliance, it also requires a strong experience of the practitioner.

The current quantification criteria are therefore not very objective, depend on the practitioner's expertise and do not allow recommendations on the conduct of the session during the follow-up of the patients. Therefore, the objectification of bronchial congestion is clearly part of the improvement of the management of KR (Assess, Anticipate, Prevent, Treat). The design of specific tools dedicated to the quantified monitoring of relevant parameters of the lung condition is of definite interest to achieve these objectives.

In this context, the MUKROBS project seeks to objectivize the bronchial congestion of COPD patients, during their management by respiratory physiotherapy techniques of de-congestion by means of modulation of the expiratory flow.

The Sybille device, designed, developed and validated in the framework of a previous project funded by the ANR VirtualChest, allows continuous, non-invasive and simultaneous measurements of sound and displacement information at specific points of the thoracic cage. The investigators will conduct a measurement campaign in the context of follow-up in private practice. The measurements will be analyzed with numerical methods specifically developed in order to achieve an automatic identification of pathological respiratory sounds. The investigators will also try to localize bronchial obstructions and to correlate them with respiratory volume variations measured before, during and after the management session.