## 3 Results
### Phase 3. Implementation: System Development  
Through role-playing interactions using the WOZ prototype, the functions and configuration of the prototype application were adjusted and enhanced. Some of the initial functions were changed (e.g., the menus were rearranged to account for the clinical trial process and for the integration of duplicate menus). Data collected for concomitant medications and adverse responses met different data specifications; therefore, the two menus were designed to be separated. On the other hand, vital sign data from external devices, such as smartwatches and wearable devices, were combined with the symptom records. Since the clinical trial patient participants were not clinical professionals and were not familiar with the terms used in general clinical trials, the titles of the health report and reminder menus were changed to include more easily understandable words. The final menu lists and functions are shown in Table 2. The network comprises an external network where users' input data, an internal network used by medical staff, and a demilitarized zone (DMZ) server for the security of the internal network, as shown in Figure 3. The application server is responsible for data processing in the DMZ, and the batch server only performs the function of detecting arrhythmia in the DMZ. The application programming interface (API) server allows communication between the internal network and DMZ; the webserver manages data processing inside the internal network, and the database stores all the data that are generated. The cloud server outside the network is responsible for relaying the user's electrocardiogram (ECG) data captured from the wearable devices in real-time. The data are transferred in the following order: Data generated by the user \(\rightarrow\) application server \(\rightarrow\) API server \(\rightarrow\) database storage \(\rightarrow\) web server \(\rightarrow\) medical check. \begin{table}
\begin{tabular}{p{42.7 pt} p{284.5 pt} p{284.5 pt}} \hline \hline
**No.** & **Menu** & **Function Description** \\ \hline
1 & Self-report & Patient-generated health data (PGHD), including the user’s weight, fasting blood sugar level, blood pressure, heart rate, body temperature, and oxygen saturation, were entered and checked. \\ \hline
2 & Medication + nutrition & Medication: A medication log, which included the name and time of each medication or treatment, was maintained. The relevant data were added to the adverse reaction menu when the participants showed adverse reactions. \\ \hline
3 & Concomitant drug & In participants consuming over-the-counter drugs or health supplements other than the test drug, information about the time and amount of the drugs was entered. \\ \hline
4 & Adverse reactions & When an adverse reaction occurred, the type, location, period, action method, picture of the symptoms, etc., were recorded, and the management of persistent adverse reactions was documented. \\ \hline
5 & Symptom record & Symptom record: Cough, stuffy nose, sore throat, fatigue, headache, fever, loss of smell, loss of taste, etc. (corresponding to symptoms of COVID-19) were reported. \\ \hline
5 & Symptom record & Health Record: Blood pressure and ECG data are input through an external device (wearable device). Blood pressure: Data from all devices linked to Samsung Health can be entered. ECG: Real-time input through VP-100 (device certified by the Korea Food and Drug Administration). \\ \hline
6 & Daily to-do & The user’s medication, nutritional, and health measurement record items that must be entered each day are presented. The status changes from to-do to done when the user completes that task. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Confirmed main menu structure and functions. ECG data are transmitted through three paths. Raw ECG data are transmitted in the order mentioned above, whereas the arrhythmia detection algorithm runs in the batch server and transmits the result to the API server.