To appear in IEEE ICEIC 2015 Diagnosing COPD Using Mobile Phones Haya Hasan, Basel Safieh, Fadi Aloul, Assim Sagahyroon American University of Sharjah, UAE Abstract—Chronic Obstructive Pulmonary Disease (COPD) is common progressive lung disease that causes difficulty in breathing. The paper presents the design and implementation of a user-friendly mobile phone application developed on an Android platform that examines the lung functionality using the phone’s built-in sensors. It allows the user to get a sense of whether they have COPD or not from home before visiting a specialized clinic and performing advanced medical tests. The proposed system will make use of the phone’s microphone to record exhalations. By means of advanced signal processing techniques, the application will be able to mimic the medical spirometer and determine certain lung measurements that are used to assess the lungs’ well-being and diagnose COPD. Furthermore, the application will allow the users to share test results with doctors who can directly assess the disease progression and give advice accordingly. The application was successfully tested among a number of users. Experimental data show promising results which can enhance the quality of life for COPD patients. I. INTRODUCTION Chronic Obstructive Pulmonary Disease (COPD) is one of the most common lung diseases. It causes poor airflow in the lungs which leads to shortness of breath, coughing, wheezing, chest tightness, and sputum production. Although the disease can be manageable if diagnosed early, it is often left undiagnosed which could lead to the destruction of the lungs over time and hence increases the rates of motility and morbidity. A typical case would be reported only after losing 50% to 60% of normal lung functionality. Furthermore, unlike Asthma, the lung functionality in a COPD patient doesn’t improve significantly with medication. According to the World Health Organization [1], COPD was the 3 rd leading cause of death worldwide affecting 329 million people or 5% of the world’s population. More than 3 million people were killed in 2012 because of COPD, which suggests that one person was killed every 10 seconds by the disease. Tobacco smoking is considered one of the main causes of COPD. Other causes include air pollution, inhalation of chemicals and dust as well as second hand smoke and genetics. Patients with COPD suffer on a daily basis when performing routine activities. They cannot withstand simple physical activities such as going up the stairs or having a walk. A COPD patient would feel exactly as a person doing aerobics when doing simple life activities. COPD is typically diagnosed by measuring the amount of air flow in the lungs using a traditional spirometer that is available in medical clinics. Affordable portable home spirometers are available today, but are limited in terms of measurement options, processing power and memory. Furthermore, they don’t provide feedback from specialized doctors. Recently, the utilization of hand held devices such as mobile phones in health-related applications have been on the rise. The rich features that today’s mobile phones are equipped with provide industry and researchers with a valuable opportunity to continue improving human life by developing applications that address a wide spectrum of issues. This paper presents the design and implementation of a mobile phone application that utilizes its built-in microphone to record the user’s exhalation. The recording is then analysed on the phone using advanced algorithms to assess the lung’s functionality and the possibility that a user might be suffering from COPD. The application is free as it doesn’t require anything but the mobile phone and its built-in sensors. The application allows for the data to be shared with specialized doctors for feedback and advice. The rest of the paper is organized as follows. Section II provides a background of COPD and discusses related work. Section III describes the proposed system hardware and software architecture. The testing and implementation results are reported in Section IV. Finally, the conclusion is presented in Section V. II. BACKGROUND & RELATED WORK Lung diseases are divided into two main parts: obstructive and restrictive pulmonary diseases. Both types of diseases make the patient suffer from shortness of breath specifically referred as Dyspnoea in medical terms. Dyspnoea is a medical condition which is considered as a common symptom between obstructive and restrictive lung diseases which varies in intensity based on the severity of the disease. Diseases that are considered under the obstructive category include COPD, Asthma, Cystic Fibrosis and Bronchiectasis. Obstructive diseases make exhalation of air difficult and slow. The air is exhaled slowly which may result in a large amount of air lingering in the lungs even after a full exhalation. However, restrictive diseases are related to causes that make the lungs stiff or hard. Therefore, the lungs cannot expand fully. This might be caused by obesity or Muscular Dystrophy. Most people with COPD have a combination of chronic bronchitis and/or emphysema. Chronic bronchitis is a condition which causes the obstruction and inflammation of the air pipes and passages. This makes them narrower and unable to carry the regular amount of air to and from the lungs. Furthermore, it also leads to an increase in mucus production and coughing. On the other hand, emphysema is another condition which leads to the walls between the air sacks in the lungs known medically as alveoli to break down and get damaged. As a result, there is less space for air exchange and the oxygen intake becomes less which leaves the user in state of dyspnoea. A user suffering from COPD needs to continuously monitor the progression of the disease to avoid the worsening of the symptoms and permanently damaging the lungs. COPD symptoms typically consists of the following: (1) Chronic Cough with a wheezing sound, (2) dyspnoea which progresses and becomes persistent, and (3) heavy mucus production and cough with sputum. COPD is typically diagnosed using spirometry which consists of measuring the volume of air exhaled after a maximum inhalation. The procedure is also used for diagnosing other pulmonary diseases such as Asthma. A patient performing spirometry is supposed to inhale the most amount of air they can and then forcefully exhale into a pipe or tube. The spirometry test is usually performed using a mouth piece that a person uses when exhaling and a nose clip. The nose clip is used to make sure that all the air is exhaled through the mouth. Furthermore, patients are usually given verbal instructions to exhale hard and as much as possible during the test. The test records two values: (1) FVC – Forced Vital Capacity which represents the total volume of air exhaled in one breath and (2) FEV1 – Forced Expiratory Volume in One Second which represents the volume of air exhaled in one second. A healthy user typically exhales 75-80% of the FVC in the first breath and has a FEV1/FVC ratio higher than 70% [2, 3]. According to the National Institute of Clinical Excellence, a COPD user would have an FEV1 value less than 80%