A smart wearable contact microphone patch for extended and remote monitoring of lung functions

Project Summary Respiratory diseases (RDs) like asthma and chronic obstructive pulmonary disease (COPD) are among the leading causes of death in the US and impose a major economic burden on the healthcare system. Early detection and monitoring of a patient’s lung function, respiratory abnormalities and their exacerbations plays a crucial role in evidence-based disease management to reduce morbidity, mortality, and cost associated with COPD readmissions. Current monitoring and diagnostic methods rely on costly and time-consuming clinical visits, discouraging preventative screening. Patients without severe symptoms often wait until they become chronic and need more specialized care. In addition, diagnosis often relies on detection of intermittent abnormal lung sounds and respiration patterns, which would benefit from prolonged recordings outside the clinic setting. Auscultation is a well-established non-invasive diagnostic method for RDs through detection of lung sounds. Stethoscopes have been used by physicians for over two centuries, but they are unsuitable for extended and remote monitoring of respiratory activity due to their large form-factor and dependence on continuous listening and interpretation by an experienced physician. In this project, we aim to create a smart easy-to-use low-profile wearable device for accurate detection and quantification of adventitious lung sounds as well as breathing abnormalities via prolonged mechano-acoustic measurements without relying on continuous listening by a skilled physician. To achieve this goal, StethX proposes to develop a battery-powered wireless wearable patch with a small footprint close to a typical band-aid utilizing a novel hermetically-sealed low-noise and low-power chip- scale contact microphone technology that is insensitive to airborne ambient sound. The wearable patch will be easy to apply and can be comfortably worn at multiple locations for prolonged continuous auscultation measurement, accompanied with machine learning algorithms for automatic detection and classification of wheezes, crackles, and breathing patterns. The contact microphone patch is immune to airborne ambient sounds as it only picks up the subtle vibrations of a surface it is mounted on, with high sensitivity. The patch can simultaneously record respiratory sounds in a wide frequency range up to 10 kHz, along with low-frequency respiratory rate, heart rate, breathing pattern, and physical activities and position of the wearer (DC and low-frequency contents). Performance of the miniaturized wearable patch will be optimized and benchmarked against state-of-the-art digital stethoscopes for feasibility assessment. The feasibility study done in Phase I of the project will pave the way for large-patient-pool evaluation and commercialization of the technology in Phase II. Once commercialized, our wearable solution is expected to greatly improve the accessibility, accuracy, and comprehensiveness of asthma and COPD diagnosis with prolonged recording and a pathway to automatic pathological signal detection by digitizing respiratory sound signals and correlating it with heart sounds and chest motions.