INTRODUCTION At present, the number of senior citizens in the world tends to increase every year. As reported by the World Bank the number of senior citizens in the world is around 0.5 billion people or 8.2% and around 74.3% of them have hypertension [1]. In the same way, the number of Thai senior citizens tends to increase. According to the National Statistical Office, the number of senior citizens in Thailand is around 10 million people or 14.9% [2]. The number of senior citizens shows that Thailand’s society will become a senior’s society soon. From the information of Thai Health Promotion Foundation, senior citizens in Thailand is around 4.1 million people or 41.0% who have high blood pressure or hypertension [3]. High blood pressure is the most common risk factor to other diseases such as stroke, kidney disease, paralysis, and so on. Therefore, high blood pressure is a very important disease that needs to be treated. Nowadays, there are many medical devices that can use to monitor people health in ever day life such as heart rate monitor, glucose monitor, blood pressure monitor, pedometer and weighing scale. Blood pressure monitors are also now available to use anywhere. Accordingly, senior citizens can use these devices to measure blood pressure at home. The hypertension patient should measure the blood pressure and take care oneself at home that is the best way to measure blood pressure [4] [5]. Moreover, most of people do not know the factors that impact the value of blood pressure such as body mass index (BMI), eating too much sodium, eating too less potassium, alcohol addiction, smoking, lack of physical activities, stress and taking the medicine according to the doctor. Thus, they should know more the basic knowledge of hypertension. In 2016, smartphone owner in Thailand is about 24 million people and about 2.5% of them are senior citizens [6]. Recently, Thai people are increasingly interested in selfcare but most user interface of self-care applications are not friendly for senior citizens e.g. small text, small button [7]. The main objective of this research work is to design and develop a self-care android application for senior citizens with hypertension to guide, track and treat hypertension and to reduce the risk of having other incurrent diseases. Hence, this oHealth application will be a useful tool for senior citizens with hypertension to take care of themselves.
BACKGROUND AND RELATED WORK A. Senior Citizens The definition of senior citizens from the United Nations is people who are more than 60 years of age. The senior citizen can separate into 4 types which are the young – old (60 to 69 years old), the middle-aged old (70 to 79 years old), the old-old (80 to 90 years of age), and the very old-old (90 to 99 years old). At present, the number of senior citizens in Thailand tends to increase every year. When seniors get older, health problems occur with them in many ways [1]. B. High blood pressure (Hypertension) Normally, blood pressure when the heart pump blood (systolic) is below 120 mmHg and blood pressure when the heart relaxed (diastolic) is below 80 mmHg. Blood pressure can be changed over time, especially when people sleep, wake up, exercise, stress, or exited. But it will be back to normal blood pressure when people finish their activities. If people finish their activities, but the blood pressure still higher than 120/80 mmHg. This means people can have high blood pressure (Hypertension) [8].
High blood pressure can divide into three levels, which are prehypertension (120-139/80-89 mmHg), high blood pressure stage 1 (140-159/90-99 mmHg), and stage 2 (more than 160/100 mmHg) [4]. There are two types of high blood pressure, which consist of primary and secondary high blood pressure. More than 90% of hypertension patients have primary high blood pressure. It is the most common type that occurs in people. And another 10% have secondary high blood pressure. There are many causes, factors and treatments of primary and secondary high blood pressure as summarized in Table 1 [8] [9] [10].
High blood pressure can divide into three levels, which are prehypertension (120-139/80-89 mmHg), high blood pressure stage 1 (140-159/90-99 mmHg), and stage 2 (more than 160/100 mmHg) [4]. There are two types of high blood pressure, which consist of primary and secondary high blood pressure. More than 90% of hypertension patients have primary high blood pressure. It is the most common type that occurs in people. And another 10% have secondary high blood pressure. There are many causes, factors and treatments of primary and secondary high blood pressure as summarized in Table 1 [8] [9] [10].
From the observation, most existing applications do not provide medicine reminder, BP reminder, knowledge, treatment, and daily emotion features in their applications. Accordingly, oHealth was proposed in order to provide all of alternative features from every application that are suit for users. Furthermore, oHealth has design that supports senior citizens directly, such as use minimalist design, provide large icons, avoid the use of irrelevant information, and maximize contrast and avoid use of excessively bright colors [17]. D. Blood pressure devices In the present, there are many blood pressure devices that can connect with smartphones, such as Welch Allyn 767, Omron M7, Withings, iHealth BP7, QardioArm, etc. According to the comparison of four smartphone compatible blood pressure monitors research [18], BP5 device can measure with higher accuracy than the other devices. Blood pressure 5 (BP5) produced by iHealth Labs, Inc., can work with both Apple and Android devices by connecting via Bluetooth V3.0. This device can measure blood pressure and pulse. The pressure accuracy of BP5 is minus 3 and plus 3 mmHg. The pulse accuracy of BP5 is minus 5 and plus 5 percentages. The range that BP5 can measure blood pressure is around 0 to 300 mmHg. E. High blood pressure data set A data set from the Statistical Society of Canada is used learning and classifying hypertension levels. Thirteen variables relevant to hypertension causes and factors are selected for analysis which are systolic blood pressure, gender, marital status, smoking status, age, weight, height, body mass index (BMI), exercise level, alcohol use, stress level, hypertension level and salt (NaCl) intake level from food [19].
The oHealth system architecture as shown in Fig. 1 has five main actors. The first actor is senior citizens with hypertension who can use oHealth by connecting with Wi-Fi or a mobile Internet data in Android device. The second actor is the administrator who maintains the database on Azure SQL Database cloud server. The third actor is doctor, assistant, and family members who receive history data and blood pressure analysis report of senior citizens. The fourth actor is BP5 device which can measure blood pressure. The last actor is azure machine learning which gets all the collected data and analyze hypertension levels for the user. The oHealth application requires the user to register as a member by providing their personal information and log-in. The application offers six main features. The first feature is user profile, which keeps senior’s information. The second feature is measure blood pressure, which measures blood pressure by connecting blood pressure device. The third feature is knowledge, which gives knowledge about hypertension, food, exercise, and medicine. The fourth feature is treatment, which records food dairy, medicine intake, and exercise for using in hypertension analysis and treatment. The fifth feature is reminder, which uses to set reminder to measure blood pressure and take medicines in each day. The last feature is analysis, which analyzes hypertension levels with azure machine learning system by using Multiclass Logistic Regression algorithm [20] to create a predictive model and shows the result to the user. The analysis results and history data can be shared to doctors, assistant, or family members.