RBDmodel-io

Repository containing the Rigid Body Dynamic MATLAB model of the spine, referenced in Dukkipati & Driscoll 2025

S. T. Dukkipati and M. Driscoll, "Evaluation of a Fast-Solving Rigid Body Spine Model Inclusive of Intra-Abdominal Pressure," in IEEE Transactions on Biomedical Engineering, doi: 10.1109/TBME.2025.3561692.

Project Overview

This repository provides a MATLAB/Simulink implementation of a rigid body dynamic (RBD) model of the human spine, including intra-abdominal pressure (IAP) effects. The model is designed for fast simulation and benchmarking, and is referenced in the above publication.

Main Files

• RBDmodel_io.slx / main_model.slxp: Simulink models of the spine.
• benchmarking.m: MATLAB script to benchmark model compile and run times.
• README.md: Project documentation.
• CITATION.cff: Citation information.
• LICENSE: MIT License.

Simulink Model Structure

The Simulink model (RBDmodel_io.slx or main_model.slxp) consists of: - Model Workspace: Contains all tunable parameters. Parameters ending with _FIXED are not user-editable. - Inputs: Muscle forces, moments, and intra-abdominal pressure (see table below). - Model_Outputs Subsystem: All outputs are available here. Use Simulink scopes or "To Workspace" blocks to view/export results.

Model Inputs

| Parameter | Description | |--------------------|----------------------------------------------------------| | IAPPa | Intra-abdominal pressure in Pascals, used in IAP Model 1 | | LeftRA/RightRA | Left and right rectus abdominus muscle force in Newtons | | LeftMF/RightMF | Left and right rectus multifidus force in Newtons | | LeftIO/RightIO | Left and right internal oblique muscle force in Newtons | | LeftEO/RightEO | Left and right external oblique force in Newtons | | MomentFE | Flexion-Extension Moment at L1 in Nm | | MomentLB | Lateral bending Moment at L1 in Nm | | MomentAR | Axial rotation Moment at L1 in Nm |

Model Outputs

• All outputs are available in the Model_Outputs subsystem.
• To view outputs, open the corresponding Simulink scope or use "To Workspace" blocks to export data.

Running the Model

1. Open MATLAB and navigate to the RBDmodel-io directory.
2. Open the Simulink model (RBDmodel_io.slx or main_model.slxp).
3. Adjust input parameters in the Model Workspace as needed.
4. Run the simulation.
5. View outputs in the Model_Outputs subsystem.

Benchmarking Script

The benchmarking.m script benchmarks the model's compile and run times: - Edit numRuns to set the number of repetitions. - Run the script in MATLAB. It will print average and standard deviation for compile and run times.

Windows/MATLAB Notes

• This project is tested on Windows with MATLAB and Simulink.
• Some files (.mexw64, .slxc, .slxp) are platform-specific or binary.
• For editable model files, contact the authors.

Citation

If you use this software, please cite: S. T. Dukkipati and M. Driscoll, "Evaluation of a Fast-Solving Rigid Body Spine Model Inclusive of Intra-Abdominal Pressure," IEEE Transactions on Biomedical Engineering, 2025. DOI

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Contact

For questions or editable model files, contact the authors: - Siril Dukkipati: siril.dukkipati@mail.mcgill.ca - Mark Driscoll: mark.driscoll@mcgill.ca