An embedded sensor network $($sensor node$)$ is a network of embedded computers$/$devices placed in the physical world that interacts with the environment and physical parameters. These embedded computers, or sensor nodes, are often physically small, relatively inexpensive computers, each with some set of sensors or actuators. One application of embedded sensor network is the smart watch.

$($i$)$ Briefly describe at least TWO types of sensors used and its application which is beneficial to the users' health.

$(2$ marks$)$

$($ii$)$ In your opinion, describe the disadvantage of monitoring the current health status for a person.

$(2$ marks$)$