Instrumentation of Human Surrogates for Side Impact 962412
The purpose of this study was to investigate the use of the chestband in side impact conditions by conducting validation experiments, and evaluating its feasibility by conducting a series of human cadaver tests under side impact crash scenarios. The chestband validation tests were conducted by wrapping the device around the thorax section of the Side Impact Dummy at its uppermost portion. The anthropomorphic test device was seated on a Teflon pad on a platform to accept impact from the side via a pendulum system. Tests were conducted at 4.5, 5.7, and 6.7 m/sec velocities using round and flat impactors. Retroreflective targets were placed at each strain gauge channel on the edge of the chestband. The test was documented using a high-speed digital video camera operating at 4500 frames/sec. Deformation contours and histories were obtained using the chestband electronic signals in combination with the RBAND-PC software. These data were compared with the digital video information processed using a computer tracking system. The overall mean change in the difference in the normalized chest deformations obtained from the chestband sensors differed by 1.38% (±SD: 0.65) when compared with the data from the video motion analysis system. When the deformations were subdivided into the medial-lateral and antero-posterior directions, and into the flat and the round impactor groups, the results indicated the mean differences to be within 2%. These findings illustrated the feasibility of the device to be used under side impact conditions.
Five unembalmed human cadavers were tested with varying velocities, under rigid wall and padded interactions, and with and without initial pelvic offsets, to demonstrate the feasibility of this device to be used to obtain biomechanical data. The surrogates were instrumented at three levels: the upper band was just under the axilla at the level of rib 4, the middle band was at the level of the xiphoid process anteriorly, and the lower band was at the T10 level. Detailed autopsy was conducted following the test. Padded tests demonstrated lower AIS scores with fewer rib fractures than the rigid wall tests. The pelvic offset test produced the greatest number of injuries with a significant fracture of the acetabulum on the struck side. Chest deformation contours typically demonstrated inward compression on the struck side and outward expansion along the anterior direction. The chestbands demonstrated consistency in the output from the upper, to the middle, to the lower levels, and from test-to-test indicating their robustness.