Rapid Low-Cost Production of a Patient-Specific Thumb Orthosis Using Smartphone Light Detection and Ranging (LiDAR)...

Three-dimensional (3D) printing technologies are increasingly used to produce patient-specific orthoses. Traditional manufacturing methods, such as plaster casting, are fast to apply but produce heavy, non-removable, and poorly ventilated immobilization devices. Many digital workflows for producing custom orthoses require expensive scanners and commercial software, limiting their widespread clinical use. This technical report presents a rapid, low-cost workflow for producing a patient-specific orthosis using a smartphone's light detection and ranging (LiDAR) scanner, free software, and fused deposition modeling (FDM) 3D printing. The workflow included 3D scanning of the injured limb using an iPhone 15 Pro LiDAR scanner (Apple Inc., Cupertino, CA, USA), mesh processing and region selection in Meshmixer (Autodesk, Inc., San Rafael, CA, USA), orthosis shell generation in Shapr3D (Shapr3D Zrt., Budapest, Hungary) with a shell thickness of 2-2.4 mm, integration of fixation elements for Velcro straps, print preparation, and additive manufacturing using an FDM 3D printer (Bambu Lab X1C; Bambu Lab, Shenzhen, China) with polylactic acid (PLA) filament. The orthosis was designed for thumb immobilization and fixed using three Velcro straps positioned around the wrist, thumb, and metacarpal region. The total production time from scanning to orthosis placement was approximately three hours. The scanning and digital modeling process took less than one hour, while the 3D printing process was the main time-consuming step. The final orthosis weighed 43 g, was ventilated, removable, and appeared to provide adequate immobilization of the thumb and wrist. The presented workflow enables rapid, low-cost, and accessible production of patient-specific orthoses using consumer-grade hardware and free software. The method enables same-day orthosis production and may be particularly useful in emergency departments, outpatient clinics, and educational settings where rapid, personalized immobilization is required.