Soft tissue elastometer

Abstract

We have developed a device entitled the 'Tissue Elastometer' (TE) for evaluating the Young's modulus of soft tissues. Soft tissue specimens are compressed between the object plate of an electronic balance and a linearly actuated indenter with a small rounded tip. The hardware of the device was designed such that a deformation model for semi-infinite media is applicable for calculating the Young's modulus of test specimens from their collected force-displacement data.Force-elongation measurements were performed on long strips of cured silicone mixtures to produce calibrated, tissue-mimicking test samples for the TE in a Young's modulus range of 10-400 kPa. When tested with the TE, the Young's moduli of the silicone samples demonstrated accuracy to within 1-10% of their calibrated values. Testing on excised tissue samples (fresh store-bought poultry breast; bovine liver, kidneys, hind shanks; porcine) was also performed, and a repeatability of elasticity measurements was demonstrated in the range of 8-14%. Results indicate that the TE can be effectively used in laboratory and clinical environments to evaluate the elasticity modulus of tissues.

Dynamic deformation using adaptable, linked asynchronous FEM regions

“…The studies [Egorov et al 2008;Li et al 2006;Yu et al 2006;Sinkus et al 2000] on the elastic properties of soft tissue reveal that soft tissue shows complex visco-elastic and non-linear characteristics. The elasticity values measured in the different studies are: between 5 and 35 kPa in [Egorov et al 2008], 6 and 11 kPa in ], 0 and 3.5 kPa in [Sinkus et al 2000] and 9.3 kPa in [Yu et al 2006]. The difference in the mentioned studies is related to tissue type, the magnitude of deformation, the non-linear behaviour of the elasticity and the level of precompression as discussed in [Samani et al 2003].…”

Towards multi-modal image-guided tumour identification in robot-assisted partial nephrectomy

“…The stiffness matrix K is built using the material parameters, Young's modulus and Poisson ratio, adopted from the literature [11]. The elements' topology is obtained from kidney and tumour 3D segmentations meshed using Gmsh 1 .…”

Inverse analysis and robustness evaluation for biological structure behaviour in FE simulation: application to the liver

“…Another solution consists to use inverse analysis (Miller 2000, Tillier et al 2003, Durand-Reville et al 2004, Egorov et al 2008) at the structure level. A numerical model of the liver governed by a finite number of parameters must then be built.…”