Strain determination in bone sections with simultaneous 3D digital holographic interferometry

• Optical system proof of principle for measurements in biological samples.
• Experimental displacement and strain measurements in bovine femoral bone.
• Simultaneous acquisition capability of the system to record a fast sequence of images for time-resolved measurement.
• Fast 3D optical measurement system and processing for surface strain data.
• Use of one single monochrome sensor and no moving parts during the recording process.

A 3D digital holographic interferometer was used to measure the surface strain components in two different bovine׳s bone sections. The applied force on the sample was induced by a precisely controlled lateral micro compression. The simultaneous acquisition capability of the system helps to record a fast sequence of images, each one containing three independent holograms that result in three orthogonal displacement components u, v and w from which the surface strain components ɛx, ɛy and γxy over the bone׳s field of view were calculated. This research study was carried out in two different bone sections: the cortical bone and the medullary cavity/yellow marrow section. The resulting strain concentrators are of great importance to better understand the mechanical response of complex biological structures such as this bovine femoral bone.