Secure fixation of endotracheal tubes (ETT), nasogastric tubes (NGT), and oral bite blocks is essential in both adult and pediatric intensive care units (ICUs). Conventional adhesive-based methods often cause skin injury, unstable positioning, repeated re-fixation, and increased workload. Existing commercial devices rarely integrate NGT or bite block support, which contributes to fragmented workflows and a higher risk of dislodgement.To evaluate the usability and clinical applicability of an innovative three-in-one fixation and adjustment device that simultaneously secures ETT, NGT, and the bite block.Guided by design thinking principles, the device was co-developed by nursing faculty and students to address key clinical pain points. A usability study was conducted with 20 participants in a laboratory simulation. Participants completed a four-item usability assessment, and qualitative feedback was analyzed thematically.Participants included clinical nurses (70%), nursing faculty (15%), and nursing students (15%). They reported improved tube stability, reduced unplanned displacement, and decreased reliance on adhesive tape, particularly beneficial for pediatric patients with smaller facial contours and sensitive skin. The adjustable structure enhanced fixation symmetry and reduced lateral shifting, while integrated bite block positioning offered greater precision than traditional methods. Workflow advantages included faster setup, easier repositioning, and reduced material use. Suggested refinements included improved cushioning, longer straps for larger facial profiles, and increased adaptability. The device has been submitted for patent protection (Taiwan Patent Application No. 114116XXX) and has received multiple national and international innovation awards.User feedback aligned closely with the five core design principles. The three-tube modular integration addressed workflow fragmentation and reduced the need for repeated taping. The four-point adjustable frame improved fit and stability, as noted in comments about decreased lateral shifting. The extended cushioned bite block enhanced comfort and oral protection, especially in pediatric care. The modular base-and-attachment system increased flexibility and reduced waste. Philtrum-centered anchoring with four-point pressure distribution reflected users' appreciation for improved comfort and reduced pressure risk.This three-in-one fixation device demonstrates strong usability, clinical relevance, and scalability across ICU settings. Further real-world testing and refinement will support the broader adoption of this approach. Keywords: Extubation, Medical Device, Patient Safety, User-Centered Design, Workflow