In the domain of soft tissue biomechanics, the development of numerical simulations has raised the experimental challenge of identifying local internal mechanical constitutive data of heterogeneous organs (e.g. brain tissue). In this context, this paper presents an ex-vivo alternative characterization method to full-field imaging techniques. It is based on automated, multiple indentations of an organ section using a custom-built rig, effectively allowing to map the viscoelastic and hyperelastic constitutive parameters of the tissue at the millimetre scale, under dynamic conditions. In this paper, this technique is described and used to map the constitutive data of three sections from porcine liver, kidney and brain tissues. The results of this mapping present strong evidence of correlation between the organ constituents (e.g. white/grey matter distribution) and the identified constitutive parameters. It was also found that brain and kidney tissues are highly heterogeneous in terms of identified properties, suggesting that such a technique is essential for fully characterizing their mechanical behaviour. This method opens the way to 3D mapping of constitutive parameters to feed finite element models of the organs with region-specific properties.

在软组织生物力学领域，数值模拟的发展提出了识别异质器官（例如脑组织）的局部内部机械本构数据的实验挑战。在这种情况下，本文提出了一种全场成像技术的离体替代性表征方法。它基于使用定制钻机的器官切片的自动多个压痕，有效地允许在动态条件下以毫米为单位绘制组织的粘弹性和超弹性本构参数。在本文中，描述了该技术并将其用于绘制猪肝，肾和脑组织三个部分的本构数据。这种作图的结果提供了器官成分之间相关性的有力证据（例如 白色/灰色物质分布）和确定的本构参数。还发现，脑和肾组织在确定的特性方面高度异质，这表明这种技术对于充分表征其机械行为至关重要。该方法为本构参数的3D映射开辟了道路，以提供具有特定区域特性的器官的有限元模型。