**1. Introduction**

Wearable devices mean whatever a person can wear since they do not restrict daily activities or mobility [1]. Recently, progress has been made in the use of wearable sensors for breathing monitoring devices, so that it is considered a promising area [2]. Many applications, including sleep monitoring [3], breathing pattern detection, and respiratory rate detection [4, 5], require comfortable and wearable devices that patients can wear in their homes, if possible, for continuous monitoring and storage of relevant data. Other requirements for wearable devices involve (i) the ability to share patient data with healthcare professionals, researchers, and family, (ii) very low energy consumption and long battery autonomy, and (iii) wireless communication with other devices [1, 6].

The main topics for the development of wearable devices for breathing monitoring and pattern detection are discussed in this chapter.
