T-test is a 4-in-1 tongue coating detection and cleaning device designed for seniors. It utilizes optical technology to monitor tongue coating thickness, color, and saliva pH levels. T-test helps maintain oral health by recording and analyzing data via a mobile app, tracking daily changes, identifying potential issues, and guiding oral care adjustments. With its cleaning module, it enables tailored tongue cleaning based on recommendations. The daily data also aids doctors in making precise diagnoses and treatment decisions, ensuring optimal oral care for seniors.