The client of the thesis was Heart2Save. The goal of Heart2save is to offer a trustworthy and easy to use solution for monitoring heart arrythmia. The devices created by Heart2Save are clinically validated and have CE-certificate meant for medical devices. The thesis's goal is to provide new information about Awario® -service's development possibilities for more anthropocentric service, which, to the user, offers guidance and care for arrythmias as much as possible. During the study of the thesis, it was noticed how important it is to consider usability of the device during the design phase as this is directly linked to user experience. The user experience affects directly how easily users will take it into use. In addition to these, the study found how important it is to take into consideration different kind of people and their needs during the design phase of the product. The operation of heart and different kind of arrhythmia are also covered by the thesis, when related to the topic of the thesis. It also covers what kind of requirements are demanded from health devices and what kind of device is helpful for the user in usability perspective. In the thesis ECG monitoring capabilities, technological solutions, and usefulness for diagnostic purposes of different kind of wearable devices are compared. In the view of the results the way of monitoring ECG does differ between different kind of devices and most common way to monitor ECG was by using optically LEDs. Reliability of LED based EKG monitoring is not as good as the technology Heart2Save Awario® Gem -device (Necklace-ECG) use. An Awario® Gem -device monitors ECG with help of an electrode creating a single-lead ECG, which is then sent via Bluetooth-connection to analysis service, which, in turn, analyses the grade of arrhythmia. The ECG monitored by Awario® Gem -device is reliable for diagnostic purposes.