SoftFLOW 50 is suitable for settings of ICU/in-patient departments and home, etc, and dedicated to the treatment of acute respiratory diseases and rehabilitation of living standard. SoftFLOW 50 outputs stable and warm moist air flow with automatically mixing in a certain amount of oxygen according to the demand, then directly sending the flow into patient's nasal cavity through a special, light and comfortable tube terminal instead of the respirator to entitle patients with a significant sense of ventilation, and their breathing can be deeper and more comfortable, which especially contributes to high quality sleep at night. This product is developed under strict implements of usability process from analysis and evaluation to design and verification. AXSED studies different foreseeable environments and users’ usage, especially for those at home, making the human-machine interaction process safer, more intuitive and comfortable, getting excellent user feedback. The layout of the information on the interface is clear and logical, in line with the patient's perception. After the information is reorganized, the buttons are minimized to present main tasks, such as airflow values and key settings of the device. By comparing the color and shape of the interface, emphasizing the simple and understandable logic. After the Usability Evaluation & UT, the design results that meet the cognitive intuition are achieved. The liquid level of the embedded liquid container inside the device can be displayed by the liquid column in the front of the machine. The whole machine’s friendly warm White and shallow Grey combination and the dark gray human-computer interaction button form a logical contrast with the human cognitive feeling, and the smooth surface of the machine is easy to be cleaned and disinfected daily.