Design of a Biofidelic, Instrumented 2. 5 Kg Infant Dummy N Design of a Biofidelic, Instrumented 2.5 Kg Infant Dummy N. Rangarajan, Ph.D., J. Mc Donald, BSME, T. Shams, Ph.D., R. Delbridge, MSME GESAC, Inc T. Fukuda, Y-M. Liu, MD, K. Kawasaki, H. Morishima, Y. Tokushige Aprica, Inc 11/21/2018 GESAC, Inc

Aprica 2.5 infant dummy 11/21/2018 GESAC, Inc

Presentation Sequence Need for an infant dummy Anthropometry of dummy Instrumentation Design of body segments Response of dummy under static loading Reproducibility and repeatability Future work Acknowledgement and References 11/21/2018 GESAC, Inc

Need for an infant dummy Children and infants spend more and more time in cars. Infants have difficulty supporting their heads. Therefore, when an infant is seated in a traditional child seat, there is concern that the oxygen saturation level in the blood stream may be compromised due to positional apnea. Test tools for conducting dynamic tests of infants on car seats and car beds not currently available. 11/21/2018 GESAC, Inc

Data needed to design infant dummy Anthropometric data. Static and dynamic response data for various body segments Injury reference values for various body segments. These are needed to decide on instrumentation for body segments. 11/21/2018 GESAC, Inc

Anthropometry of infant dummy - 1 Anthropometry of dummy corresponds to 10th percentile Japanese infant [JMoT data]. Segment and other data obtained by measuring 4 infants at a hospital in Osaka, Japan. Where needed, infant anthropometry data from CMVSS 213.5 was used. Range of Motion [RoM] data were estimated from adult RoM. 11/21/2018 GESAC, Inc

Anthropometry of infant dummy - 2 Item 1st infant Avg. 3 infants Design goal Mass 2,572g 2,603g 2,600g Height 0.45m 0.44m Arm length 0.18m 0.183m Leg length [crotch to heel] 01.5m 0.152m 0.15m Top of head to shoulder 0.11m 0.108m 11/21/2018 GESAC, Inc

Anthropometry of infant dummy - 3 Item 1st infant Avg. 3 infants Design goal Head circum. 0.31m 0.34m 0.35m Head length 0.118m Head width 0.88m 0.95m Head Depth 0.14m 0.112m Neck Circumf. 0.18m 0.187m 0.172m Neck length 0.05m 0.054m 11/21/2018 GESAC, Inc

Anthropometry of infant dummy - 4 Item 1st infant Avg. 3 infants Design goal Shldr circum. 0.3m 0.322m 0.297m Chest circum. 0.29m 0.315m 0.298m Waist circumf. 0.31m 0.323m 0.318m Hip circumf. 0.28m 0.285m 0.286m Upr arm circumf 0.08m 0.093m Thigh circumf. 0.13m 11/21/2018 GESAC, Inc

Anthropometry of infant dummy - 5 Item 1st infant Avg. 3 infants Design goal Head mass 0.8 kg Upr arm mass 0.029 kg Lwr arm mass 0.022 kg Upr leg mass 0.082 kg Lwr leg mass 0.048 kg 11/21/2018 GESAC, Inc

Anthropometry of infant dummy - 6 Estimated Joint Loads Joint Max. Load (N)/Torque (Nm) Neck 1, 000 / 60 Shoulder 100 / 10 Pelvis / lumbar 2,000 / 200 Hip 300 / 30 Knee 100 / 5 11/21/2018 GESAC, Inc

Response and Injury Assessment Reference Values [IARV] Static and dynamic response data for body segments estimated from available adult response data. Available response corridors shown with dummy’s response in static tests. Injury reference values to be developed 11/21/2018 GESAC, Inc

Aprica 2.5 infant dummy 11/21/2018 GESAC, Inc

Design of Body Segments Head - 1 Two-stiffness casting or Urethane. Scalp stiffer than flesh. Flesh stiffness about durometer 30A 11/21/2018 GESAC, Inc

Design of Body Segments Head - 2 Assembled view of head with sensors 11/21/2018 GESAC, Inc

Design of Body Segments Head - 3 11/21/2018 Design of Body Segments Head - 3 This figure shows the inner harder scalp and the outer, softer flesh. Bottom view of head casting 11/21/2018 GESAC, Inc

Design of Body Segments Head - 4 11/21/2018 Design of Body Segments Head - 4 3 accels mounted on a cube around the head cg can be used to calculate HIC. Head instrumentation holder with 3 accelerometers 11/21/2018 GESAC, Inc

Design of Body Segments Neck - 1 11/21/2018 Design of Body Segments Neck - 1 Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Neck showing housing for accelero- meters at top and bottom. 11/21/2018 GESAC, Inc

Design of Body Segments Neck - 2 11/21/2018 Design of Body Segments Neck - 2 Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Neck mounted on T-spine with accels 11/21/2018 GESAC, Inc

Design of Body Segments Neck - 3 11/21/2018 Design of Body Segments Neck - 3 Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Neck with neck shroud 11/21/2018 GESAC, Inc

Design of Body Segments Thorax - 1 11/21/2018 Design of Body Segments Thorax - 1 Thorax consists of : 1. Shoulder 2. Thoracic and lumbar spines 3. Thoracic flesh and response element Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. 11/21/2018 GESAC, Inc

Design of Body Segments Thorax – 2 [Skeleton] 11/21/2018 Design of Body Segments Thorax – 2 [Skeleton] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Skeletal layout showing shoulder, T-spine and tri-axial accels 11/21/2018 GESAC, Inc

Design of Body Segments Thorax – 3 [Shoulder] 11/21/2018 Design of Body Segments Thorax – 3 [Shoulder] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Delrin shoulder block showing ball joint for the arm. 11/21/2018 GESAC, Inc

Design of Body Segments Thorax – 4 [T-spine] 11/21/2018 Design of Body Segments Thorax – 4 [T-spine] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Urthane and Aluminium T-spine with tri-axial accels 11/21/2018 GESAC, Inc

Design of Body Segments Thorax – 5 [Response Unit] 11/21/2018 Design of Body Segments Thorax – 5 [Response Unit] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Foam response unit and tri-axial accelerometers 11/21/2018 GESAC, Inc

Design of Body Segments Thorax – 6 [Thoracic flesh] 11/21/2018 Design of Body Segments Thorax – 6 [Thoracic flesh] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Infant dummy showing thoracic flesh 11/21/2018 GESAC, Inc

Design of Body Segments Pelvis – 1 [Pelvic Bone] 11/21/2018 Design of Body Segments Pelvis – 1 [Pelvic Bone] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Infant dummy pelvic bone 11/21/2018 GESAC, Inc

Design of Body Segments Pelvis – 2 [Pelvis Accels] 11/21/2018 Design of Body Segments Pelvis – 2 [Pelvis Accels] Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Pelvis tri-axial accelerometers 11/21/2018 GESAC, Inc

Sample static response data - Neck 11/21/2018 Sample static response data - Neck Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Neck response data against scaled Mertz corridor 11/21/2018 GESAC, Inc

Sample static response data - Thorax 11/21/2018 Sample static response data - Thorax Hope to calculate NIC which is a function of the acceleration of the lower and upper accelerometers. Thorax force-displacement data showing repeat- ability in static tests 11/21/2018 GESAC, Inc

Future work - 1 Dummy needs to be dynamically tested to confirm biofidelity. Test methodology to be developed. Scaled response corridors developed. Following tests are under consideration: Kroell test for thorax Head-neck pendulum test for neck to compare data with Mertz corridor Head drop tests. 11/21/2018 GESAC, Inc

Future work - 2 Injury causation mechanism to be evaluated. Measurable variables relating to injury to be developed. Dynamic sled testing needs to be conducted to evaluate sled performance of dummy. Robustness of the dummy needs to be evaluated through repeated testing. Repeatability needs to evaluated. Reproducibility to be evaluated. 11/21/2018 GESAC, Inc

Future work - 3 Data from dynamic and sled tests to be used to develop appropriate lumped mass and FE models. 11/21/2018 GESAC, Inc

Acknowledgement Development of dummy was supported by funding from Aprica Child Care Institute, Japan. 11/21/2018 GESAC, Inc

References - 1 McPherson, G, T. Kriewall. 1980. The elastic modulus of fetal cranial bone: A first step towards an understanding of the biomechanics of fetal head modling. Journal of Biomechanics, Vol. 13, #1, pp 9-16. Melvin, J. 1995. Injury assessment reference values for the CRABI 6-month infant dummy in rear-facing infant restraint with airbag deployment. SAE Paper No. 950872 11/21/2018 GESAC, Inc

References - 2 Mertz, H. 1984. A procedure of normalizing impact response data. SAE Paper No. 840884 Mertz, et al. 1989. Size, weight and biomechanical impact response requirements for adult size small female and large male dummies. SAE Paper No. 890756 11/21/2018 GESAC, Inc

References - 3 Ratingen, M, et al. 1997. Biomechanically based design and performance targets for a 3-year old child crash dummy for frontal and side impact. SAE Paper No. 973316 Robbins,D. 1983. Anthropometric specifications for mid-sized male dummy. Final report. Contract DTNH22-80-C-07502. 11/21/2018 GESAC, Inc

References - 4 Schneider, L, D. Robbins, M. Pflug, and R. Snyder. 1983. Development of anthropometrically based design specifications for an advanced adult anthropometric dummy family. UMTRI Report Np. UMTRI-83-53-1. 11/21/2018 GESAC, Inc

Aprica 2.5 infant dummy 11/21/2018 GESAC, Inc

Thank you 11/21/2018 GESAC, Inc