Low-cost foil based wearable sensory system for respiratory sound analysis to monitor wheezing

We present a sensory system made from aluminum foil that can be attached to the human chest like a stethoscope for real-time asthma symptom monitoring. The sensor is designed such that it resonates around the dominant frequency of wheezing (a common symptom of asthma). This helps the sensor produce large output signals so that it can be directly integrated with a microprocessor without the need for signal amplification circuits. The data is stored in the chip and analyzed to determine if wheezing has occurred. Matched filtering algorithm is used to extract and detect features of wheezing from the acquired chest sounds. The sensor successfully detects wheezing from the human chest, even when subjected to background noise and other lung sounds. Matched filtering algorithm is even able to detect between different types of wheezing sounds. Such a real-time wheezing detection system can help prevent asthma at early stages or allow early intervention when a patient undergoes an asthma attack.