Approximately 5% of the elderly people, over age 65, suffer from one kind of dementia such as Alzheimer’s disease, frontotemporal dementia and AIDS dementia. It is estimated population of senior citizens all over the world will almost double in the next 25 years. Accordingly, prevalence of dementia in aging generation increases essential need in resources dedicated to caretaking of senior citizens, such as facilities, financial and human resources. It opens doors to emergence of new semantic technologies, which aim to assist senior citizens in daily life tasks. The systems should be safe, effective and patient-centered, and they must provide timely, efficient and equitable care to patients. Focuses on health, physical condition monitoring and assistive navigation technologies are the main categories to improve life quality of senior citizens. This study is dedicated to introducing a Head Mounted Display system to assist senior citizens in daily navigational tasks. In addition, usability test infrastructure is explained to evaluate system usability and improve the system in iterative test plans. The main research question clarifies main objective of the study as an investigation on usability of HMD system through several sub-questions evaluating various factors in the system and customers’ preferences. HMD system consists of the Indicator-based Smart Glasses and Bluetooth headset. Set of LED indicators is implanted around the lenses in the frame of the Smart Glasses. LED cues are supposed to convey navigational commands to users. Design science method with applied qualitative and quantitative approaches defines research method while Goal Question Metrics forms the framework of the study to improve the usability of the system. Satisfaction level and various metrics in the system are evaluated via unstructured interviews, Bayesian analysis and measuring quantitative variables. Furthermore, severity of dementia is assessed through questionnaires in MMSE from. Evaluating different factors and metrics in the system through iterative usability tests lead to improvement in design and defining optimized blinking patterns in LED indicators configurations to convey navigational commands. Blinking patterns in the Smart Glasses include localizing indicators, blinking duration time, frequency and brightness. Usability tests with senior citizens as subject demonstrates that severity level of dementia could strongly affect users’ performance. Senior citizens who are suffering from severe and moderate dementia fail to accomplish the tasks in using the assistive tool. Accordingly, senior citizens, who are suffering from mild dementia and are in the initial stage of dementia, should be considered as the subject of future usability tests
