ASME Journal of Biomechanical Engineering Editors' Choice highlights paper exploring arterial tissue fusion
PhD Student Eric Kramer (MechEngr'16) dissects tissue in the Advanced Medical Technologies Laboratory
Only twelve out of over one-hundredpapers that appeared in the ASME Journal of Biomechanical Engineering, were selected by the editorial board to be published as one of the Journal of Biomechanical Engineering Editors' Choice papers for 2018.
One such paper,“A smalldeformation thermoporomechanics finite element model and its applicationto arterial tissue fusion” was written by Mechanical Engineering professors and graduate students, including PhD student Doug Fankell, PhD student Eric Kramer, Associate Professor Ginger Fergusonand Associate Professor Mark Rentschler, along withCivil, Environmental, and Architectural Engineering Associate Professor Rich Regueiro.
An excerpt from this paper isincluded below.
Introduction
Biological tissue undergoes thermal loading in several mannersranging from surgical devices that heat or cool biological tissue tocauterize or ablate it, to natural causes such as hyperthermiaor frostbite. Scientists and physicians seek to understandtheseprocesses and their impact on tissue mechanics to create novel,safer, and more effective medical devices and procedures. Withtissue–device interaction becoming ever more prevalent in theform of more complex medical devices, wearable electronics, andimplanted electronics, experimental testing is becoming increasinglyexpensive in time and resources. Computer simulations ofthese interactions, when calibrated to experimental data, provideessential insight into the underlying physics occurring in biologicaltissuewhen deformed and heated, allowing for streamlineddesign work and ultimately more effective devices and safer procedures.Additionally, models with the ability to accurately andquickly predict surgical outcomes will help satisfy the growingdesire for patient specific, near real time, simulations for surgicalprocedures.
A good deal of biological tissue is nonhomogenous and typicallycontains several materials, often in different phases. Forexample, the artery wall has an extracellular matrix (ECM) madeup of collagen, elastin, and glycosaminoglycans. While water isattracted to molecules within the tissue through polar interactions,it readily moves through interstitial spaces. Thus, this tissue canbe considered as a porous medium. Studies attempting to modelbiological tissue,including vertebral disks, articular cartilage, lung tissue, arterial tissue, skin, tumor, andmyocardial tissueas a porous medium exist throughout literature;however, these attempts have failed to completely representthe complex physicsoccurring within the tissue. Typically, modelsrepresenting biological tissue as porous media fall into one oftwo categories. The first neglects deformation and only heat and/or mass transfer is represented. The second category ofmodels uses solid mechanics and mass transport to model tissuedeformation and coupled pore fluid flow, but thermal transport isnot considered. To the authors’ knowledge, no modelexists that demonstrates the coupled solid phase (ECM) mechanics,mass transfer, and heattransfer (thermoporomechanics(TPM)) occurring in biological tissue. In this paper, a small deformation,TPM finite element (FE) model with the ability to representthe heating and deformation of biological tissue is presented,and its results are validated by comparisonto measured experimentalresults of thermal arterial tissue fusion.