Acorn 3D Software (AC-SEG-4009); Acorn 3DP Model (AC-101-XX)

Acorn 3D Software is a modular image processing system that imports, visualizes, and segments CT/CTA medical images to create 3D digital models. The new Alignment & Measurement module allows users to align anatomical structures between datasets, perform spinopelvic measurements on 3D anatomy models, and plan surgical procedures in pediatric and adult patients. The segmentation output can also be used to fabricate 3D-printed physical replicas (Acorn 3DP Models) for diagnostic and surgical planning purposes in musculoskeletal and craniomaxillofacial applications.

Acorn 3D Software includes DICOM image import, image processing with noise-reduction filters, visualization, automatic/semi-automatic/manual segmentation tools, 3D model generation and editing, measurement capabilities, and image registration. The new Alignment & Measurement module adds registration of anatomical structures between datasets and spinopelvic measurement functionality based on user-defined anatomical reference geometry. A machine learning U-Net algorithm automates segmentation of vertebrae (T1-T12, L1-L5) and sacrum. The system is standalone modular software that exports data in JSON and STL formats.

Not stated in this summary. The document references software verification and validation per FDA guidance on premarket submissions for medical device software, quantitative bench testing for alignment accuracy (Target Registration Error methodology), and machine learning model performance testing using DICE similarity coefficient (DSC) metrics, but does not cite specific consensus standards such as ISO, IEC, or ASTM.

The Acorn 3D Alignment & Measurement module is substantially equivalent to the predicate Acorn 3D Software (K234009) because both share the same intended use for image visualization, segmentation, measurement, and treatment planning; the same technological characteristics including modular architecture, DICOM import, segmentation tools, and 3D model creation; and the same regulatory classification (Class II, 21 CFR 892.2050). Quantitative testing demonstrated registration accuracy (Median TRE 1.70–4.33 mm) equivalent to the predicate, and both are used with expert clinical judgment for musculoskeletal and craniomaxillofacial applications.