Sensors are increasingly being employed to determine different activities of a person living at home. Numerous sensors can be used to obtain a variety of information. While many sensors may be used to make a system, it is important to look into the availability, cost, installation, mechanism, and performance of sensors. This chapter investigates different sensors and their usefulness in a smart home monitoring system. A smart home monitoring system provides a safe, sound, and secure living environment for elderly people. Statistics show that the population of elderly people is increasing around the world and this trend is not going to change in the near future. The authors have developed a smart home that consists of an optimum number of wireless sensors that includes current flow, water flow, and bed usage sensors. The sensors provide information that can be used for monitoring elderly people by detecting abnormal patterns in their daily activities. The system generates and sends an early warning message to the caregiver when an unforeseen abnormal condition occurs.
Top1. Introduction
Recent statistics indicate that the population that is 60 years or older is steadily on the rise throughout the world as is shown in Figure 1. It is estimated that by 2050 this particular group will have globally increased by over 50% (DESA, 2007). There are many people in our community who because of age or some infirmity, or perhaps because their memory and judgment can no longer be totally relied upon, are having pressure put on them to leave their home and give up their precious independence.
Figure 1. Estimates and projections for the population aged 60 and over (Bryant, 2008)
Over the past century, the average life expectancy of humans has increased and has almost doubled. The maximum life span—the longest number of years a human being has lived—has also increased spectacularly as shown in Figure 2.
Figure 2. Life expectancy around the world (UCSC, 2010)
Increased life expectancy can cause an immense stress on the scarce resources available to care for the elderly. Therefore the importance of enabling the elderly to live in their own home as long as possible is crucial. However, if they prefer to live alone they do require constant monitoring so that medical help can be provided immediately in times of dire needs. The smart home concept is a promising way to improve the living standards of elderly by improving the home care facilities. The smart home monitoring system can circumvent the institutionalization of the older people and can help them live at home in safety and with independence. The smart homes target to improve comfort, quality of life and safety by monitoring mobility and physiological parameters. Modern sensors not only assist and monitor people with reduced physical functions but help to resolve the social isolation they face. They are capable of providing assistance without limiting or disturbing the resident’s daily routine, giving him or her greater comfort, pleasure, and a sense of well-being. A number of smart homes have now been developed around the world by many institutes and researchers (Yamaguchi, Ogawa, Tamura, & Togawa, 1998; Eriksson & Timpka, 2002; Dengler, Awad, & Dressler, 2007). The smart home is based on smart and intelligent sensors, which are developed, fabricated and configured around a wireless network. It is expected that these smart homes will reduce escalating medical costs.
Housing Learning & Improvement network published a smart home definition offered by Interetec, which states that a smart home is “a dwelling incorporating a communications network that connects the key electrical appliances and services, and allows them to be remotely controlled, monitored or accessed (Jiang, Liu, & Yang, 2004).
1.1. A Need for Detection of Changes Using Wireless Sensor Technology
Any abnormal events which can occur to an old person in a home often leads to more serious illnesses or even death. Such abnormal activities need to be monitored so that early corrective actions can be initiated. Similarly, the changes in sleep pattern, changes in physiological parameters, and even changes in the cognitive abilities, are essential to managing the changing health status of the elderly person. So a system and method has been developed for monitoring an individual, especially an elder person living independently, by distinguishing his/her abnormal activity from normal activities. This technological assistance and monitoring of a person in the home is achieved using a few but effective wireless sensors, which are centralized in structure and distributed around the house. These sensors capture the activity of the person and the collected data is communicated to a remote monitoring center using wireless data transfer techniques.
The system captures the activities of the resident, and stores as data points in a database. One of the aspects of this system is to distinguish between normal and unusual activity in a home. This is achieved by evaluating the new data points against the collated historical activity data present in the database.