Overview
ISO/TR 13219:1995 is an ISO Technical Report (type 3) that provides a statistical risk curve linking Hybrid III sternal deflection to the probability of serious thoracic injury (AIS ≥ 3) due to shoulder belt loading. The report documents the choice of a probit-based risk curve (with 95% confidence limits) derived from sled-test data and real-world accident correlations. The curve is intended for use with the Hybrid III anthropomorphic test device (ATD) and applies only to sternal deflection measurements recorded from that dummy.
Key topics
- Hybrid III sternal deflection: Use of chest/sternum compression measured on the Hybrid III dummy as the injury metric.
- Thoracic injury risk (AIS ≥ 3): A statistical relationship between measured sternal deflection (mm) and the probability of an AIS 3 or greater thoracic injury under shoulder-belt loading.
- Probit analysis and confidence limits: The probit-based risk curve was selected (with 95% confidence intervals). An alternative bounded analysis is discussed and shown to be consistent.
- Data sources and validation: Curve development used sled tests reproducing force-limiter tearing levels and correlated these Hybrid III responses with occupant injury frequencies from accident data (see referenced studies by Mertz et al., Foret-Bruno, Horsch, etc.).
- Scope limitation: The risk curve is valid only for Hybrid III sternal deflection measurements and for shoulder-belt loading conditions; it should not be applied to other ATDs or non-shoulder-belt loading modes without appropriate validation.
Applications and users
Practical uses include:
- Evaluating belt-induced thoracic injury risk in frontal crash simulations and sled tests.
- Comparing and optimizing shoulder belt designs, force limiters, and restraint systems to minimize chest compression and injury probability.
- Informing vehicle safety engineers, restraint-system designers, crash-test laboratories, regulatory analysts, and safety researchers when interpreting Hybrid III chest deflection data.
- Supporting design trade-offs in occupant protection and restraint tuning by providing a quantifiable risk metric.
Who will use it:
- Automotive safety engineers and crashworthiness teams
- Test laboratories conducting Hybrid III frontal crash or sled tests
- Regulators and policy analysts assessing belt-related thoracic injury risk
- Biomechanics researchers comparing ATD responses to field injury data
Related standards
- Hybrid III ATD specification (e.g., 49 CFR Part 572, Subpart E) - referenced in the report bibliography.
- ISO/TC 22 / SC 12 publications on restraint systems and crash test procedures (see report bibliography for related SAE and ISO references).
This Technical Report is primarily an informative tool to translate Hybrid III sternal deflection into an evidence-based estimate of serious thoracic injury risk for shoulder-belt loading scenarios.