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Research

Funding & Partners

Our research is supported by competitive federal grants and strong cross-institutional collaborations.

National Institutes of Health
National Science Foundation
Kennesaw State University
Emory University
01

AI-driven simulation accelerators and predictive models that replace expensive finite element solvers with learned surrogate representations.

Data Analysis & Machine Learning

We design data pipelines and machine learning models to process experimental and clinical data, classify motility patterns, and accelerate prediction and decision support.

Our machine learning research also explores spatiotemporal modeling of cardiac dynamics. Sanjian Zhang studies how to integrate cardiac structures reconstructed from CT/MRI with physiological signals, such as blood pressure, and clinical variables to model and predict cardiac motion throughout the cardiac cycle.

HeartSimSage: Attention-Enhanced Graph Neural Networks

Our flagship ML framework converts cardiac finite element meshes into graph structures, learning the relationship between geometry, material properties, loading conditions, and tissue deformation, at 13,000× GPU acceleration and 190× CPU acceleration compared to traditional FEA, with median error under 0.13%.

HeartSimSage Framework Architecture

GraphSAGE Topology

Flexible node connectivity on unstructured cardiac meshes.

Laplace-Dirichlet Encoding

Mesh-aware spatial embedding via Laplace equation solutions.

Attention Mechanism

Adaptive message passing with dynamic neighbor weighting.

Subset Training

Efficient subgraph sampling to reduce memory footprint.

Project Visualization

Video: HeartSimSage predicting cardiac tissue deformation compared with finite element results.
13,000×
GPU Acceleration
190×
CPU Acceleration
0.13%
Median Error
0.28mm
Max Displacement Error

Related Publications

  • Shi L*, Chen Y, Vedula V. Journal of Computational Physics, 2026. HeartSimSage framework for AI-accelerated cardiac biomechanical simulations.

Interested in This Research?

Tell us your major, year, and what caught your eye. We'll reply within a week.

Contact Dr. Shi
02

Multiscale & Multiphysics Simulation

Research Lead Nanlong Sun

Cross-scale computational modeling and coupled multiphysics simulations, from molecular ion channels to whole-organ electromechanics.

Imaging, Reconstruction & Digital Twins

We integrate CT scans, endoscopy images, and manometry data from clinical collaborators to build accurate 3D models of the stomach, esophagus, and heart. These models are the geometric foundation for every digital twin we construct.

On top of that geometry, we develop patient-specific digital twins that couple tissue mechanics with electrical activity to simulate how each organ contracts, moves, and responds to disease or surgical intervention.

3D-0D Electromechanical Coupling

Implicit coupling framework that integrates 0D ion-based electrophysiology models with 3D finite-element solid mechanics, enabling patient-specific simulation of cardiac and gastric motility.

Cardiac Digital Twin Multiscale Modeling

Figure 1: Multiscale modeling of a patient-specific cardiac digital twin.

3D Solid Mechanics

Nonlinear finite-element mechanics with large deformation kinematics.

0D Electrophysiology

Ion-channel models of electrical activity (e.g., Hodgkin-Huxley type).

Mechano-Electric Feedback

Bidirectional coupling between tissue deformation and electrical activity.

Implicit Coupling

0D and 3D models solved together within one implicit coupling framework.

4D Patient-Specific Imaging

Integration of time-phase CT and MRI imaging to construct personalized 3D organ geometries that evolve physiologically throughout the cardiac or respiratory cycle.

Segment Multi-atlas + deep-learning organ segmentation
Morph Non-rigid registration for motion estimation
Mesh Hex-dominant discretization with quality control

Project Visualization

Applications

01

Personalized Diagnosis

Patient-specific mechanical predictions for improved clinical accuracy.

02

Surgical Planning

Pre-operative biomechanical simulation of bariatric and GI procedures.

03

Gastric Pacemaker Design

Optimizing electrode placement for electrical stimulation devices.

04

Population-Scale Studies

Efficient computation enabling large-cohort biomechanical research.

Related Publications

  • Shi L*, Chen IY, Vedula V. Computer Methods in Applied Mechanics and Engineering, 2026. Personalized multiscale modeling of left atrial mechanics and blood flow.
  • Vedula V, Shi L, Gan BB. APS Division of Fluid Dynamics, 2024. Multiscale electromechanics modeling framework.

Interested in This Research?

Tell us your major, year, and what caught your eye. We'll reply within a week.

Contact Dr. Shi
03

Constitutive Modeling

Research Lead Yue Li

Physics-based material models that capture the complex, nonlinear behavior of biological soft tissues under large deformation.

Why Material Models Matter

Every simulation we run depends on how accurately it describes the tissue itself. Stomach, cardiac, and other soft tissues show both elastic recoil and time-dependent relaxation, so our models are calibrated against the mechanical tests performed in our lab.

Hyper-Viscoelastic Constitutive Framework

We develop microstructure-informed material models that combine hyperelastic equilibrium response with viscoelastic rate-dependent behavior, which is essential for accurate simulation of soft tissues that exhibit both elastic recoil and time-dependent relaxation.

Computational Biomechanics

Figure 1: Computational biomechanics modeling of soft tissue.

Microstructure-Informed

Material parameters tied to collagen fiber architecture and ground substance properties.

Large Deformation

Validated across physiological strain ranges (up to 40–60%) with anisotropic fiber reinforcement.

Viscoelastic Coupling

Prony-series based time-dependent response with separable hyperelastic equilibrium.

Cross-Validation

Identified via inverse calibration against biaxial, uniaxial, and shear experimental data.

Project Visualization

Related Publications

  • Shi L*, Myers K. Journal of the Mechanics and Physics of Solids, 2026. Microstructure-informed hyper-viscoelastic model for gastric tissue.

Interested in This Research?

Tell us your major, year, and what caught your eye. We'll reply within a week.

Contact Dr. Shi
04

Explore our laboratory equipment and contact us to discuss experimental testing and research collaborations.

Overview of the Instron 68SC-1 testing machine, BioPuls biobath, and surrounding DIC cameras

Universal Testing Machine & BioPuls Biobath

Manufacturer Instron
Model 68SC-1
Overview of the Sakura Tissue-Tek Cryo3 Flex cryostat

Cryostat

Manufacturer Sakura
Model Tissue-Tek Cryo3 Flex

Interested in Collaborating?

Share your research goals, sample type, testing needs, and expected timeline with our team.

Contact Dr. Shi