# A User-Centred Well-Being Home for the Elderly
## 2 A Model of Wellbeing for the Elderly  
One of the foremost questions considered when trying to define a model for which an elders' home IoT solution might be unified is which facets of a person's life it should touch. Consequently, the model is composed of three dimensions: health, activity and emotional, as represented in Figure 1.  
Figure 1: The three dimensions of well-being. Even if sometimes these are observed isolated from each other, in literature as well as in some solutions, the fact is that on some occasions they are intrinsically related. Hence a change in one of the dimensions will affect other(s). Certainly, a chronic health problem, for many persons, will affect their emotional state. Similarly, it may prevent them from performing some type of activities. This dependency which is observed sometimes isn't by any means always negative. More positive relations may also occur. For instance, someone that is emotionally strong and is in a good physical shape (e.g., because of some daily activity) may also be less affected by some health complications and/or more easily surpass them. Although other or more dimensions might have been selected, we selected these because of their noticeable contribution to the well-being of the elderly. Moreover, they were also chosen considering that some signals may be attained from sensors to determine some aspects related to these three dimensions. For example, a sensor measuring the heart rate can tell us something about the health. Sensors in appliances and sports machines can identify the activity that is being carried out and for how long and the type of activity (e.g., sports activity, entertainment--such as watching the favourite TV show). Finally, a camera capturing facial expressions can tell us something about the emotional state. For sure, all the factors that may influence a person's well-being, their relative importance and what can actually be measured and/or influenced with today's technology justifies further investigation. Considering these three dimensions, it is possible to identify all the entities which may be present in a home that in some way can intervene with the resident. We classify these entities into three categories: agents, devices and geography elements. These may be interpreted as an overview for much of the different types of objects that compose a home in the vast literature e.g., [40; 41; 42; 43] that can be found nowadays about smart homes, smart environments or ambient assisted living (just to name a few of the most common terms found). Analogous to Figure 1 these are represented as user-centred graphics as in Figure 2.  
On this classification, the agents represent all the entities that may be present in a home intended to collect or transmit information to the resident. Therefore, the agents may be classified as input agents, output agents or both. Examples of input agents are cameras, panic buttons, heartbeat reader modules, etc. Output modules are projectors, stereos, notification clocks, amongst others. Agents may also be simultaneous input and output agents. An example of an output agent can be a bracelet which reads the user pulse and gives him information about eventual irregularities sensed. Figure 2: Entities of a home. Devices are the appliances of the house, i.e., the pieces of equipment operated electrically for performing domestic chores (e.g., a TV, a fridge, a washing machine, etc.). These can also act as agents, or interact with them, by collecting or transmitting information. For example, a fridge can act as an input agent, collecting information through integrated technology, which allows detecting all the goods inside it. This same fridge can also act as an output agent by emitting alerts when some specific item is missing or almost over. It can also emit alerts when expirations dates are near.