title: Simple empirical model for identifying rheological properties of soft biological tissues.
abstract: Understanding the rheological properties of soft biological tissue is a key issue for mechanical systems used in the health care field. We propose a simple empirical model using fractional dynamics and exponential nonlinearity (FDEN) to identify the rheological properties of soft biological tissue. The model is derived from detailed material measurements using samples isolated from porcine liver. We conducted dynamic viscoelastic and creep tests on liver samples using a plate-plate rheometer. The experimental results indicated that biological tissue has specific properties: (i) power law increase in the storage elastic modulus and the loss elastic modulus of the same slope; (ii) power law compliance (gain) decrease and constant phase delay in the frequency domain; (iii) power law dependence between time and strain relationships in the time domain; and (iv) linear dependence in the low strain range and exponential law dependence in the high strain range between stress-strain relationships. Our simple FDEN model uses only three dependent parameters and represents the specific properties of soft biological tissue.
authors.affiliation: Future Robotics Organization, Waseda University, Tokyo 169-8555, Japan; JST-PRESTO, Saitama 332-0012, Japan; and Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan.
authors.forename: Yo
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Faculty of Science and Engineering/Research Institute of Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Tsukune
authors.affiliation: Faculty of Science and Engineering/Research Institute of Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miyashita
authors.affiliation: Faculty of Science and Engineering/Research Institute of Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
authors.forename: Masakatsu G
authors.initials: MG
authors.lastname: Fujie
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D055119:Elastic Modulus; D017709:Fractals; D008099:Liver / Q000502:physiology; D008954:Models, Biological; D017711:Nonlinear Dynamics; D012212:Rheology; D013552:Swine; D055682:Viscoelastic Substances
chemical_list: D055682:Viscoelastic Substances