Characterization of Frequency-Dependent Material Properties of Human Liver and its Pathologies Using an Impact Hammer

TL;DR

This study introduces a simple impact hammer method to characterize the frequency-dependent elastic properties of human liver tissue, effectively distinguishing between healthy and diseased states based on their dynamic modulus variations.

Contribution

The paper presents a novel, efficient approach using an impact hammer to measure frequency-dependent properties of human liver, enabling differentiation of fibrosis levels.

Findings

Healthy livers have lower storage modulus than cirrhotic livers.

The method can differentiate fibrosis stages based on modulus variation.

Dynamic elastic modulus varies significantly with frequency in diseased versus healthy tissue.

Abstract

The current methods for characterization of frequency-dependent material properties of human liver are very limited. In fact, there is almost no data available in the literature showing the variation in dynamic elastic modulus of healthy or diseased human liver as a function of excitation frequency. We show that frequency-dependent dynamic material properties of a whole human liver can be easily and efficiently characterized by an impact hammer. The procedure only involves a light impact force applied to the tested liver by a hand-held hammer. The results of our experiments conducted with 15 human livers harvested from the patients having some form of liver disease show that the proposed approach can successfully differentiate the level of fibrosis in human liver. We found that the storage moduli of the livers having no fibrosis (F0) and that of the cirrhotic livers (F4) varied from 10 to 20 kPa and 20 to 50 kPa for the frequency range of 0 to 80 Hz, respectively.