## 2 Literature Review
Neuroppsychiatric diseases are the primary cause of disability globally, but current mental health monitoring methods rely on subjective DSM-5 specifications; however, developments in EEG and video monitoring technology have not been extensively embraced because of inconvenience. [PERSON] and [PERSON] [22] presented a novel platform-the Passive, Real-time Information for Sensing Mental Health (PRISM)--through the integration of heart rate, light, and motion data from a smartwatch application and text input from a web application. The SUS questionnaire was used to evaluate its usability, and a total of 13 healthy participants were asked to wear the Samsung Gear S smartwatch for usability evaluation. The SUS questionnaire demonstrated that participants had a positive attitude toward PRISM. The participants said that the system was simple to use, requiring little expertise or training; however, they lacked the motivation to use it regularly. In the study of [PERSON] et al. [23], the authors evaluated user satisfaction, usability, and compliance with the help of a real-time, online assessment and mobility monitoring (ROAMM) mobile app designed for smartwatches. In the study, 28 participants were asked to wear smartwatches and fill out a standardized questionnaire. The ROAMM wristwatch app received high marks from older people with knee osteoarthritis, indicating their satisfaction with the app. The condition of atrial fibrillation (AF) is difficult to diagnose since it often presents with mild symptoms. Smartwatches can be used for long-term, non-invasive monitoring, which could improve AF care. The main objective of the study of [PERSON] et al. [24] was to evaluate the efficacy of arrhythmia discrimination using a wristwatch. A total of 40 participants were observed, and a questionnaire was completed evaluating several aspects of the device's usability. A real-time algorithm was used to analyze the pulse recordings. The results showed that the majority of participants thought the smartwatch was very usable. The general level of comfort and the level of data privacy when wearing a wristwatch for rhythm monitoring were both positively correlated with younger age and past cardioversion, respectively. The participants deemed the smartwatch to be extremely acceptable despite their age, lack of knowledge of smartwatches, and a significant load of comorbidities. Although smartwatches may be potential tools for atrial fibrillation identification, elderly stroke patients have not been given enough attention. [PERSON] et al. [25] introduced the pulse watch, a smartwatch-based AF detection system, and evaluated its precision, usability, and adherence in stroke patients. The participants filled out questionnaires to evaluate numerous psychosocial factors and health-related behaviors. The results demonstrated that older stroke patients found the scheme useful and would stick to the monitoring schedule. Smartwatches have also been demonstrated to accurately assess blood pressure in glaucoma patients; however, their usability evaluation has been neglected in previous research. For this purpose, [PERSON] et al. [26] conducted an experiment where adult participants received a wristwatch blood pressure monitor for indoor monitoring using the Omron BP monitor and an associated mobile app. Usability testing methodologies included the post-study system usability questionnaire (PSSUQ), which was used for assessing aspects of user satisfaction such as the overall system usefulness, information quality, and interface quality, and the system usability scale (SUS), which was used to assess the overall usability of smartwatches. Furthermore, usability on the basis of age, gender, and race was also evaluated. The usability evaluationsdemonstrated that the smartwatches had satisfactory usability ratings, although older age was linked to lower levels of perceived usability and user experience. Table 1 shows the current state-of-the-art methods to evaluate the usability of smartwatches.