An investigation of how specimen dimensions affect biaxial mechanical characterizations with CellScale BioTester and constitutive modeling of porcine tricuspid valve leaflets

Devin W Laurence; Shuodao Wang; Rui Xiao; Jin Qian; Arshid Mir; Harold M Burkhart; Gerhard A Holzapfel; Chung-Hao Lee

doi:10.1016/j.jbiomech.2023.111829

An investigation of how specimen dimensions affect biaxial mechanical characterizations with CellScale BioTester and constitutive modeling of porcine tricuspid valve leaflets

J Biomech. 2023 Oct 5:160:111829. doi: 10.1016/j.jbiomech.2023.111829. Online ahead of print.

Authors

Devin W Laurence¹, Shuodao Wang², Rui Xiao³, Jin Qian³, Arshid Mir⁴, Harold M Burkhart⁵, Gerhard A Holzapfel⁶, Chung-Hao Lee⁷

Affiliations

¹ Biomechanics and Biomaterials Design Laboratory, The University of Oklahoma, USA.
² School of Mechanical and Aerospace Engineering, Oklahoma State University, USA.
³ Department of Engineering Mechanics, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
⁴ Department of Pediatrics, University of Oklahoma Health Sciences Center, USA.
⁵ Department of Surgery, University of Oklahoma Health Sciences Center, USA.
⁶ Institute of Biomechanics, Graz University of Technology, Austria; Department of Structural Engineering, Norwegian University of Science and Technology, Norway.
⁷ Biomechanics and Biomaterials Design Laboratory, The University of Oklahoma, USA; Institute for Biomedical Engineering, Science and Technology, The University of Oklahoma, USA; Department of Bioengineering, The University of California, Riverside, USA. Electronic address: clee@ucr.edu.

PMID: 37826955
PMCID: PMC10995110 (available on 2025-04-05)
DOI: 10.1016/j.jbiomech.2023.111829

Abstract

Biaxial mechanical characterizations are the accepted approach to determine the mechanical response of many biological soft tissues. Although several computational and experimental studies have examined how experimental factors (e.g., clamped vs. suture mounting) affect the acquired tissue mechanical behavior, little is known about the role of specimen dimensions in data acquisition and the subsequent modeling. In this study, we combined our established mechanical characterization framework with an iterative size-reduction protocol to test the hypothesis that specimen dimensions affect the observed mechanical behavior of biaxial characterizations. Our findings indicated that there were non-significant differences in the peak equibiaxial stretches of tricuspid valve leaflets across four specimen dimensions ranging from 4.5×4.5mm to 9 × 9mm. Further analyses revealed that there were significant differences in the low-tensile modulus of the circumferential tissue direction. These differences resulted in significantly different constitutive model parameters for the Tong-Fung model between different specimen dimensions of the posterior and septal leaflets. Overall, our findings demonstrate that specimen dimensions play an important role in experimental characterizations, but not necessarily in constitutive modeling of soft tissue mechanical behavior during biaxial testing with the commercial CellScale BioTester.

Keywords: Biaxial tensile testing; Constitutive modeling; Heart valve leaflet; Specimen dimension.

Grants and funding

R01 HL159475/HL/NHLBI NIH HHS/United States