안면부 필러 시술 시 니어미스 예방을 위한 웨어러블 초음파 기기의 사용적합성 형성평가

Abstract

Filler injection procedures are widely performed for facial contouring and rejuvenation but may cause severe complications such as skin necrosis or blindness if filler material is inadvertently injected into blood vessels. To improve procedural safety, a finger-mounted wearable ultrasound was developed to enable realtime vascular visualization and needle guidance. This study aimed to evaluate the usability of the device through a formative evaluation based on the IEC 62366-1/2 standards. Materials and Methods: Six physicians (four dermatologists and two general practitioners) participated in a single-session formative usability evaluation approved by the Institutional Review Board (IRB No. DUIH 2025-01-006). Five task scenarios reflecting clinical workflow were designed, including two vascular scanning and three needle guidance tasks. Quantitative metrics (task completion rate, time, attempts, and observer-recorded errors) and qualitative data (Likert-scale questionnaires and interviews) were collected under standardized conditions. Results: All participants completed every task successfully (100% completion). The mean task time ranged from 26.2 ± 8.3 s for vascular scanning to 76.0 ± 33.1 s for needle-target confirmation. Twelve usability issues were identified, mainly during needle guidance tasks. Experienced users showed longer task durations due to detailed confirmation behaviors, whereas inexperienced users completed tasks faster but less precisely. Questionnaire responses indicated high perceived usefulness (4.8/5) and ease of use (4.4/5), but lower scores for wearability (2.5/5) and UI satisfaction (3.9/5). Conclusion: The wearable ultrasound demonstrated feasibility for real-time vascular monitoring and needle guidance during filler procedures. Further improvements in UI design, calibration automation, and ergonomics are required to enhance clinical applicability.