2012 4th International Conference on Intelligent and Advanced Systems (ICIAS2012) Promoting a Healthier Life-Style Using Activity-Aware Smart Phones Adil Mehmood Khan ∗ , Muhammad Hameed Siddiqi † ∗ Division of Information and Computer Engineering, Ajou University, Suwon, Rep: of Korea. † Ubiquitous Computing Lab, Dept. of Computer Engineering, Kyung Hee University, Suwon, Rep: of Korea Abstract—Today’s healthcare delivery system faces numerous problems, such as grey-population and life-style diseases. One such life-style disease is obesity, which has seen a rapid increase over the past decade. It can now be regarded as a global epidemic that can further lead to chronic diseases, such as diabetes, stroke, high blood cholesterol, hypertension and cardiac failure. Nowadays, most people have high caloric intake due to easy access to foods and beverages with high caloric content and extremely low levels of physical activity relative to that caloric intake. In this paper, we present the preliminary results of our study where an accelerometer enabled smart phone was used to recognize a person’s daily physical activities using activity acceleration signals. These activity aware phones were then used to suggest minor behavior modifications to a person’s daily routine, such as a short walk after a long period of sitting, and walking back to lab from cafeteria. It is shown that by using this intelligent system to incorporate small modifications in their daily routine, people can boost their overall energy expenditure and thus can achieve a protective effect against lifestyle diseases like obesity. I. I NTRODUCTION Maintaining a healthy state and preventing sickness requires a healthcare infrastructure which includes a healthcare system. The motivation behind such a system is to prevent, treat and manage sickness and preserve physical and mental well- being of a person through the services offered by medical, nursing and allied health professions [1]. However, traditional healthcare delivery system failed in providing consistent, timely and high quality medical care to all people [1]. Such systems are established to help people receive the medical care that is tailored to meet their needs and is based on the best scientific knowledge, yet evidence suggests that this frequently is not the case. In fact, between the healthcare systems we have today and the healthcare systems we could have lies a huge gap [1]. There are many problems with today’s healthcare infrastruc- ture which contribute to this huge gap. The biggest and the most important one of which is the approach it takes. It focuses almost entirely on treating diseases and health problems and very little effort is spent on preventing them [2]. This leads to many problems including the high cost of treatment which is massively larger than the cost of prevention [2]. Numerous programs have shown that spending just an hour on preventive care with patients would cut down the annual medical cost significantly [2]. Moreover, there exist certain factors, more commonly known as lifestyle-diseases, which can further lead to certain chronic diseases such as diabetes, stroke, high blood cholesterol, hy- pertension and cardiac failure [3]. One such lifestyle-disease, which has seen rapid increase over the past decades, is obesity. In fact, obesity is now regarded as a global epidemic that may dramatically impact health, especially in the industrialized world [4]. This rapid increase in its widespread is generally believed to result from a caloric imbalance [5]. Nowadays, most people have high caloric intake due to easy access to foods and beverages with high caloric content and extremely low levels of physical activity to relative to that caloric intake [6]. There are two ways humans can spend the calories. One is to perform vigorous exercises such as weight training and rowing. The other is through all the activities of daily living, also known as Non-Exercise Activity Thermogenesis (NEAT). NEAT has got a lot of attention in the research community over the past decade. The theory behind NEAT is based on the fact that minor behavior modifications to a person’s daily routine, such as sitting fidgeting legs vs. sitting, standing vs. sitting, brisk walking vs. walking, and using stairs vs. elevator, can sum up over the course of day and boost overall energy expenditure and thus provide a protective effect against lifestyle diseases like obesity [7], [8]. In this paper, we present the preliminary results of our study where an accelerometer-enabled smart phone phone was used to recognize non-exercise activities using activity-acceleration signals. This knowledge was then used to suggest people minor changes in their daily routine, through text-based interventions, that might impact their daily energy expenditure positively. II. METHODOLOGY This section presents overview of the design of the proposed accelerometer-based activity recognition and intervention sys- tem. A. Activity Recognition This section describes in detail the research approach fol- lowed to collect the necessary data, feature extraction, and the classifier used for implementing the activity recognition module. It also presents the preliminary recognition results for this module. 1) Sensor Device: In this study, activity data were collected on six activities using an Android operating system based mobile phone called Galaxy S2. The six activities were: sitting, standing, walking, walking-upstairs, walking-downstairs, and riding bus. Galaxy S2 (shown in Fig. 1) is a smart phone from Samsung, equipped with a built-in triaxial accelerometer. It was configured to provide acceleration data with a sampling 978-1-4577-1967-7/12/$26.00 ©2011 IEEE [ 7 ]