Skip to main content

THOR 3D Deflection

Description​

THOR 3D Deflection reconstructs thoracic motion from three-axis IR-TRACC displacement measurements and presents an interactive chest visualization. It also reports regional and overall resultant compression and, when applicable, THOR injury probabilities [1] [2].

When this feature is available​

THOR 3D Deflection becomes available when either the current curve selection or any loaded test contains a chest measurement set that meets the requirements. Only channels with a usable data status count.

The required measurement set includes:

  • The group must contain all three displacement channels at the same attachment:
    • Axis: X - LOCAL, Units: millimeters
    • Axis: Y - LOCAL, Units: millimeters
    • Axis: Z - LOCAL, Units: millimeters
  • At least one complete three-axis set must be at the upper-left, upper-right, lower-left, or lower-right chest position.
  • Abdominal positions can be included in the result when a qualifying chest set is also available, but abdominal curves do not make the button available by themselves.

WebSAT enables THOR 3D Deflection when any supported location contains the complete three-axis set. A complete four-point chest visualization requires valid data at all four chest IR-TRACC locations, so missing locations can limit the reconstruction even when the metric is available.

Settings​

This feature has no settings.

How WebSAT processes the data​

  1. Load the THOR geometry and the available chest and abdomen IR-TRACC channels.
  2. Convert the displacement inputs to consistent units and synchronize their time histories.
  3. Reconstruct each available sensor's joint-center position.
  4. Calculate X, Y, Z, and resultant displacement for each supported region.
  5. Find the maximum compression for every available chest region.
  6. Determine the overall Rmax value and its time.
  7. Evaluate abdominal X compression when both abdominal locations are available.
  8. Build the time states used by the interactive three-dimensional animation.
  9. Report the regional results, Rmax, available injury risks, and supporting visualization.

Reference values and injury risk​

This function does not compare Rmax or abdominal compression with a fixed IARV. Instead, injury is expressed directly as an AIS 3+ probability using the THOR risk relationships [2]:

P(TIC AIS 3+)=1−e−(Rmax/58.183)2.977P(\mathrm{TIC\ AIS\ 3+})=1-e^{-(R_{max}/58.183)^{2.977}}

P(abdominal compression AIS 3+)=1−e−(Cabd/106.222)4.3127P(\mathrm{abdominal\ compression\ AIS\ 3+})=1-e^{-(C_{abd}/106.222)^{4.3127}}

where RmaxR_{max} and CabdC_{abd} are in millimeters. The TIC relationship is applied to the maximum resultant chest deflection. The abdominal relationship is applied when the required abdominal X-displacement data are available. If the inputs do not support one of these assessments, its probability field is left blank rather than substituting a fixed limit.

Results​

WebSAT interactive THOR chest displacement visualization
Interactive THOR chest reconstruction showing the chest mesh, reference geometry, and displacement state.

The summary includes Rmax, its time and region, regional X extrema and compression, abdominal compression when available, and supported AIS 3+ probabilities.

References​

[1] Humanetics Innovative Solutions. 3D IR-TRACC THOR-50M User Manual.

[2] Craig, M. et al. Injury Criteria for the THOR 50th Male ATD. National Highway Traffic Safety Administration, 2020.