Overview
ISO/TR 19222:2021 - "Road vehicles - Injury risk curves for the THOR dummy" provides a technical report of injury risk curves (IRCs) to assess occupant protection in frontal impacts using the 50th percentile THOR metric dummy (THOR‑M 50). The report compiles and evaluates injury risk functions for head, neck, thorax, abdomen and knee‑thigh‑hip (KTH) regions. Where THOR‑specific IRCs exist they are preferred; when not available, post‑mortem human subject (PMHS) curves are evaluated for applicability to THOR biofidelity. The report also addresses repeatability, reproducibility and field evaluation where possible.
Key technical topics and requirements
- Scope and methodology: Systematic collection of existing IRCs, verification of reference data, application of ISO/TS 18506 quality rules, and calculation of IRC quality indices and quotations.
- Injury criteria covered:
- Head: HIC (e.g., HIC15), rotational criteria and brain‑related metrics.
- Neck: N‑Eppinger and N‑Mertz criteria and related transfer functions.
- Thorax: maximum resultant deflection, PC‑Score (principal component score), and TIC (thoracic injury criterion).
- Abdomen: penetration criteria.
- KTH: femur z‑force, acetabulum force, and combined metrics.
- Data sources and statistics: Use of PMHS datasets, statistical methods (modified median rank, maximum likelihood), and confidence interval (CI) evaluation at 5%, 25% and 50% risk levels.
- THOR applicability & R&R: Assessment of dummy biofidelity, transfer functions (e.g., HIII‑THOR), and repeatability/reproducibility metrics for certification and sled tests (Annexes H and I).
Practical applications and intended users
- Vehicle safety engineers and test laboratories: Use IRCs to quantify occupant injury risk in frontal crash tests with THOR‑M 50 and to compare restraint systems and vehicle designs.
- Regulatory agencies and NCAP programs (e.g., Euro NCAP, US‑NCAP): Inform test procedures and scoring using THOR‑based injury metrics and evaluate IRC quality and applicability.
- Biomechanics researchers and dummy manufacturers: Validate biofidelity, develop transfer functions between PMHS and THOR, and refine injury criteria.
- Design and compliance teams: Apply IRCs for product development, safety benchmarking, and field correlation studies.
Related standards and references
- ISO/TS 18506 - rules for developing and evaluating injury risk curves (applied in ISO/TR 19222).
- ISO/TR 7861 - referenced for specific HIC‑based skull fracture data.
- Annexes in ISO/TR 19222 provide detailed datasets, transfer functions (e.g., HIII‑THOR), and repeatability/reproducibility results.
ISO/TR 19222:2021 is a practical resource for anyone implementing THOR‑M 50 testing or translating PMHS evidence to dummy measures, enabling robust injury risk assessment in frontal crash safety engineering.