Connected, smart devices are integral to the Internet of Things (IoT), of which health and wellness applications are a part of and are referred to as digital health. Devices are smart when they incorporate sensors. They are connected when they can communicate with a backend computational platform—usually implemented as a wireless link via Internet to a cloud computing platform. Connected, smart devices have many applications in monitoring us and what we do, as well as the world around us.
Let’s consider a hypothetical application to understand the typical anatomy of IoT/digital health solutions. Jugglers are a staple of entertainment! They juggle a variety of things; let’s pick balls as an example. Say jugglers are interested in quantifying their skills and performances, as well as adding a bit of bling to their show. Examples of the latter are balls that light up with a specific color at a specific altitude and canalso flash in a coordinated fashion.
The first requirement is to add sensors to the ballsto track their motion, measure their altitude and identify them individually. These tasks can be accomplished by embedding acceleration and pressure sensors in the balls to track motion and altitude, respectively. Similarly, each ball can be identified by giving it a unique radio-frequency identification tag.
The next requirement is to transmit the data from the balls. Given the nature of the application, data communication must be through a wireless link. As a result, each ball needs a wireless transceiver. Many applications use Blue Tooth Low Energy to link smart devices to user mobile phones. In effect, the phone acts as a wireless gateway to send the data to the backend. Other wireless link options are WiFi and cellular, for example. They progressively require more power at the sensor node—the ball—and are more expensive. The cellular link to the smart ball requires a data plan subscription as well, which adds operating cost.
Clearly, the smart balls need a power source which needs to be replenished periodically. Engineers use low-power electronics designs to minimize power consumption. However, power consumption is also affected by data transmission volume and rate. As a result, applications require a thoughtful planning of data processingat the sensor node—edge node—to arrive at a data volume and transmission rate that is power optimal for the intended application.
Once the data is available at the backend, data analytics techniques are used to mine information and insight from the data. The information and insight are then visualized to the juggler through a mobile application (App) running on his/her smart phone. The App is also the interface by which she/he enters and queries information. There may be a website interface as well, but increasingly less so because of preference for mobile devices. In sum, the anatomy of IoT/digital health solution comprises smart devices, connectivity, computation and mobile application software.