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Erschienen in:
14.01.2017 | Original Article
Automatic CT-based finite element model generation for temperature-based death time estimation: feasibility study and sensitivity analysis
Erschienen in: International Journal of Legal Medicine | Ausgabe 3/2017
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Temperature-based death time estimation is based either on simple phenomenological models of corpse cooling or on detailed physical heat transfer models. The latter are much more complex but allow a higher accuracy of death time estimation, as in principle, all relevant cooling mechanisms can be taken into account.
Here, a complete workflow for finite element-based cooling simulation is presented. The following steps are demonstrated on a CT phantom:
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Computer tomography (CT) scan
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Segmentation of the CT images for thermodynamically relevant features of individual geometries and compilation in a geometric computer-aided design (CAD) model
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Conversion of the segmentation result into a finite element (FE) simulation model
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Computation of the model cooling curve (MOD)
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Calculation of the cooling time (CTE)
For the first time in FE-based cooling time estimation, the steps from the CT image over segmentation to FE model generation are performed semi-automatically. The cooling time calculation results are compared to cooling measurements performed on the phantoms under controlled conditions. In this context, the method is validated using a CT phantom. Some of the phantoms’ thermodynamic material parameters had to be determined via independent experiments.
Moreover, the impact of geometry and material parameter uncertainties on the estimated cooling time is investigated by a sensitivity analysis.