The rise of the internet led to the emergence of the concept of the internet of the things “IoT”, where sensors-equipped physical devices are gathering data and transferring this data via the internet. The data are then analyzed with cloud computing. This new concept of IoT and cloud computing paved the way for wearable devices, which is now gaining popularity. 
The estimated market size of wearable healthcare devices is $150 billion in 2027,  these devices are used by patients, doctors, and nurses to monitor their day to day health life.
Before they reached such a huge market, they were just small gadgets that were used to count how many steps you walked or how many calories you burned. However, now everybody is using wearable technology not only consumers but also physicians, surgeons, and insurance companies, and with 140 million devices being sold each year worldwide, it is changing the dynamics of the whole healthcare industry. 
Now, one can monitor their own daily sleep schedule , heart rate, exercise level, and steps walked, glucose monitoring and even detect UVA and UVB exposure; using household wearables such as Fitbit, Apple Watch, Samsung Galaxy Gear, and Garmin. 
So back to numbers, it is estimated according to Statistica that the market of wearable devices reaches $34 billion in 2019, the recognized market size of $26 billion of worldwide revenue. While for healthcare and medical field applications; the growth is expected to be almost $15 billion in 2019. 
Wearable Technology in Healthcare
Wearable technology is the technology used in electronic devices which people wear on their body. These devices have sensors that collect different types of data for several reasons. 
These devices are user-friendly, patient-friendly and allow for patient-physician interaction as well. 
These devices are designed not to be conspicuous because they are worn as accessories sometimes and other times as implants. 
There are extensive industrial applications for wearable technology. Some companies use wearable devices to:
- Personalized healthcare service 
- Improvement of customer service. 
- Productivity increase.
- Providing safe working conditions for the employees.
- Prediction of employees’ injuries and accidents by analysis of fatigue and other factors.
What is Wearable Technology Used For?
These devices are used for tracking information in real-time when worn on the body; they have motion sensors that take snapshots of the day to day activity and sync them with computers or mobile devices. Areas of application are activity area, prediction and identification of events, anomaly detection and diagnosis support. 
What are wearable medical devices? 
Wearable medical devices or wearable health devices “WHDs” is emerging technology that makes continuous healthcare monitoring of vital human signs during daily life possible. These devices are used for tracking during work, at home, during sports activities, or even in a clinical environment. It has the advantage of minimizing the feeling of discomfort and interference with normal human activities.
WHD’s are used for various purposes such as medical, activities, fitness and wellness as well, yet the main reason for using these devices is the monitoring of human body vital sign.
Regardless of the purpose of WHDs, there are some main design requirements for them; these are security and reliability, low power consumption, comfort and finally ergonomics.
What is the future of wearable technology? 
Several types of accessory devices that are WHD’s are now emerging, an example is Google eye lens which is representing the future of wearable devices, as they are becoming smaller and smaller from macro scale to micro and finally to the nanoscale. Another example is the ear device that senses physiological parameters such as heart rate and oxygen saturation level. Valencell, which is a major sensing technology supplier, refers to signals coming from ear devices as 100 times more clear than those coming from the wrist. This is because the ear is mainly composed of cartilage, thus eliminating the interference coming from muscles. The same company argues that ear devices are now a new trend in wearables.
While vital signs are measured by devices worn on the wrest of inserted inside the ear, continuous monitoring of heart activity is done by three main categories of wearable device such as chest straps, t-shirts with embedded electronics and adhesive patches.
So, if we peeked into the future, one would expect that major industrial manufacturers would collaborate to create gadgets that are stylish yet concealed and offering endless solutions. This is particularity important in the healthcare area where this wearable technology is used to make monitoring devices that are embedded in other devices like hearing aids and pacemakers. 
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