Boundary Element Fast Multipole Method (BEM-FMM) for Bioelectromagnetic Modeling of the Brain

Investigators
Sergey N Makarov/Aapo Nummenmaa/William A Wartman
Contact info (email)
makarov@wpi.edu/nummenma@nmr.mgh.harvard.edu/wawartman@wpi.edu
1. Define context(s)
aid in FDA decision making
aid in clinical decision making
aid in clinical trial design
identify/explore new therapies
reveal new biological insights
Current Conformance Level / Target Conformance Level
3.0/5
Primary goal of the model/tool/database

Develop, validate, disseminate, and apply a new high-resolution numerical simulation tool for bioelectromagnetic modeling of human brain (including both neurophysiological recordings - EEG/MEG/iEEG and neurostimulation - TMS/TES/DBS) based on the new formulation of the boundary element fast multipole method - BEM-FMM.

This formulation significantly outperforms the finite element method (FEM) in both accuracy and speed (by the factor up to 100) for piecewise-homogeneous models such the standard multi-compartment head models obtained from T1/T2 MRI data.

Additionally, the tool is capable of computing electric and magnetic fields in ensembles of morphologically reconstructed realistic cortical neurons, which is impossible with the finite element method.

The tool cannot yet handle arbitrary spatial medium anisotropy but major efforts are made to solve this problem.

Biological domain of the model
Human organisms
Structure(s) of interest in the model
Central nervous system
Spatial scales included in the model
Centimeter, millimeter, micrometer
Time scales included in the model
~1 Microsecond or greater: the models are quasi-static
Other uses for the model (optional)

1. Linearized Computational Fluid Dynamics (CFD) of Cerebrospinal Fluid (CSF)

2. Linearized Computational Fluid Dynamics (CFD) of brain vascular supply

3. Linearized Computational Fluid Dynamics (CFD) of upper respiratory in application to modeling viral infections

 

Additional comments about the model’s context (optional)

The model context of use includes:

1. Applications to transcranial magnetic stimulation (TMS) - high resolution individualized TMS targeting

https://tmscorelab.github.io/TMS-Modeling-Website/

2. Applications to transcranial electrical stimulation (TES) - high resolution individualized TES targeting

https://tmscorelab.github.io/TES-Modeling-Website/

3. Application to deep brain stimulation (DBS) - computing initial polarization of axonal fiber on the microlevel

GitHub under construction

4. Application to electroencephalography (EEG) - solving the direct/inverse EEG problems for a cortical equivalent dipole layer or for more realistic ensembles of cortical neurons with the unlimited number of sources

https://tmscorelab.github.io/EEG_MEG-Modeling-Website/

5. Application to magnetoencephalography (MEG) - solving the direct/inverse MEG problems for a cortical equivalent dipole layer or for more realistic ensembles of cortical neurons with the unlimited number of sources

https://tmscorelab.github.io/EEG_MEG-Modeling-Website/

 

 

 

 

2. Data for building and validating the model
Data for building the model Published? Private? How is credibility checked? Current Conformance Level / Target Conformance Level
in vitro (primary cells cell, lines, etc.) YES NO NIH supported research 3.5/5
ex vivo (excised tissues)
in vivo pre-clinical (lower-level organism or small animal)
in vivo pre-clinical (large animal)
Human subjects/clinical YES NO NIH supported research 3.5/5
Other: ________________________
Data for validating the model Published? Private? How is credibility checked? Current Conformance Level / Target Conformance Level
in vitro (primary cells cell, lines, etc.)
ex vivo (excised tissues)
in vivo pre-clinical (lower-level organism or small animal)
in vivo pre-clinical (large animal)
Human subjects/clinical YES NO NIH supported research 3.5/5
Other: ________________________
3. Validate within context(s)
Who does it? When does it happen? How is it done? Current Conformance Level / Target Conformance Level
Verification team of developers, independent researchers 2019-2024 comparison against experiement and other software packages 4/5
Validation independent third party researchers 2019-2024 application to unique needs of different research teams 3/5
Uncertainty quantification team of developers, independent researchers 2019-2024 evaluation of low-order moments of the outputs, i.e. mean and variance 2.5/5
Sensitivity analysis team of developers, independent researchers 2019-2024 One-at-a-time (OAT), linear regression 2.5/5
Other:__________
Additional Comments
4. Limitations
Disclaimer statement (explain key limitations) Who needs to know about this disclaimer? How is this disclaimer shared with that audience? Current Conformance Level / Target Conformance Level
https://tmscorelab.github.io/TMS-Modeling-Website/Terms%20and%20Conditions.html any TMS user publications/GitHub 4/5
https://tmscorelab.github.io/TES-Modeling-Website/Terms%20and%20Conditions.html any TES user publications/GitHub 4/5
https://tmscorelab.github.io/EEG_MEG-Modeling-Website/Terms%20and%20Conditions.html any EEG/MEG user publications/GitHub 4/5
5. Version control
Current Conformance Level / Target Conformance Level
2/5
Naming Conventions? Repository? Code Review?
individual modeler v.X.Y GitHub every 6 months
within the lab v.X.Y GitHub
collaborators v.X.Y GitHub
6. Documentation
Current Conformance Level / Target Conformance Level
Code commented? YES
Scope and intended use described? YES
User’s guide? YES, all in GitHub - see three links above
Developer’s guide? NO
7. Dissemination
Current Conformance Level / Target Conformance Level
2.5/5
Target Audience(s): “Inner circle” Scientific community Public
Simulations X X
Models X X X
Software X X
Results X X
Implications of results X X X
8. Independent reviews
Current Conformance Level / Target Conformance Level
2.5/5
Reviewer(s) name & affiliation: Dr. Shelley Fried/Massachusetts General Hospital Boston
When was review performed? 2019-2020
How was review performed and outcomes of the review? Using software - software adopted
9. Test competing implementations
Current Conformance Level / Target Conformance Level
2.5/5 - Open-source FEM: SimNIBS, Roast
Yes or No (briefly summarize)
Were competing implementations tested? YES, extensively
Did this lead to model refinement or improvement? YES
10. Conform to standards
Current Conformance Level / Target Conformance Level
2/5
Yes or No (briefly summarize)
Are there operating procedures, guidelines, or standards for this type of multiscale modeling? YES
How do your modeling efforts conform? Contacting hardware providers/implementing correct device parameters/dimensions
11. (optional) Additional information to support items 1-10

GitHub links:

https://tmscorelab.github.io/TMS-Modeling-Website/

https://tmscorelab.github.io/TES-Modeling-Website/

https://tmscorelab.github.io/EEG_MEG-Modeling-Website/

Relevant publications:

  1. Makarov SN, Hämäläinen M, Okada Y, Noetscher GM, Ahveninen J, Nummenmaa A. Boundary Element Fast Multipole Method for Enhanced Modeling of Neurophysiological Recordings. IEEE Trans. Biomed. Eng. 2020 June 1. doi: 10.1109/TBME.2020.2999271, PubMed PMID: 32746015.
  2. Makarov SN, Wartman WA, Daneshzand M, Fujimoto K, Raij T, Nummenmaa A. A software toolkit for TMS electric-field modeling with boundary element fast multipole method: An efficient MATLAB implementation. J Neural Eng. 2020 Aug 4;17(4):046023. doi: 10.1088/1741-2552/ab85b3, PubMed PMID: 32235065.
  3. Htet AT, Saturnino GB, Burnham EH, Noetscher G, Nummenmaa A, Makarov SN. Comparative performance of the finite element method and the boundary element fast multipole method for problems mimicking transcranial magnetic stimulation (TMS). J Neural Eng. 2019 Apr;16(2):024001. doi: 10.1088/1741-2552/aafbb9, PubMed PMID: 30605893, PubMed Central PMCID: PMC6546501.
  4. Makarov SN, Noetscher GM, Raij T, Nummenmaa A. A Quasi-Static Boundary Element Approach with Fast Multipole Acceleration for High-Resolution Bioelectromagnetic Models. IEEE Trans Biomed Eng. 2018 Mar 7. doi: 10.1109/TBME.2018.2813261, PubMed PMID: 29993385; PubMed Central PMCID: PMC7388683.