## 2 Project Background: Wireless Data Transfer Using NFC Technology
NFC technology is increasingly used in the healthcare sector. Its usage is beneficial and facilitates the following processes: (1) physical access control--uses a contactless NFC card, which allows people to be granted access to hospital premises according to their competencies and access to medicines or medical devices and (2) logical access control--focuses on computer access control, ensuring fast, secure, and convenient access to hospital databases and medical records. Medication-control information about administered prescriptions is stored on the NFC tag assigned to the patient. Thanks to applications designed for this process, the healthcare professional can find out information about a specific patient's medication as well as information about the given prescription that the patient receives. Medical staff access patient information using an NFC reader; the data is stored on tags such as a bracelet or card. Identification is very often used in neonatal wards to identify the baby and mother and in surgical wards for patients preparing for surgery. Wireless data collection using sensors can be passive or active. The data obtained in this way are used on Internet connections and are sent to central servers, where they are processed and evaluated. NFC enables the monitoring of the patient's movement and, at the same time, staff in the area, while the nurses can check in real-time when the nurse was last with the patient and what medicines the doctor prescribed. The data are sent to a database with controlled access. The use of NFC wireless communication in healthcare has several advantages. The first is the highly secure and effortless transfer of patient information and medical records. Data transfer can happen between a patient and a healthcare professional or between two healthcare professionals in the context of information transfer during patient treatment in a hospital. The second advantage is technical security, which is more straightforward considering the types of mobile devices used by patients and medical personnel, because NFC technology is included in almost every mobile phone or tablet. Another advantage is that the technology is known to most users via NFC technology in everyday life, for instance, when paying for a purchase by mobile phone. The simple data-exchange principle does not require special training of patients or healthcare professionals. The possibility of using NFC tags is also an advantage. These tags are used to store important information that the doctor can quickly retrieve in case of emergency and provide first-aid in the form of medicines, thanks to the fact the information is stored on the tag. The patient's reaction to pharmacological treatment and the types of allergies the patient has are examples of information which can be stored. Using NFC tags to track hospital progress prevents errors and simplifies medical record-keeping. Figure 3: Essential characteristics of NFC communication protocol. The databases for the implemented project serve for virtual storage of collected data, which are then available when needed. We have established fundamental criteria for choosing the proper database, which includes real-time data acquisition, security measures, ease of access, offline data display, and affordability. The application uses databases based on real-time data synchronization and a database for recording data available in offline mode. Firebase is a NoSQL database from Google. It allows using user authentication, cloud hosting, and a real-time database. The data is accessed by the Firebase console, which retrieves the data using commands specified in the device code. Unlike SQLite, data is stored in records, not tables. Security of critical data using encryption must be done before sending the information to the service server. The advantage of the Firebase platform is that it can cooperate with the Android studio, in which we programmed the virtual patient card [21; 22; 23].