mephunter: making things easier for signal visualization and analysis
TRANSCRIPT
MEPHunter: Making things
easier for signal visualization
and analysis
Victor Hugo Souza
E-mail: [email protected]
Departamento de Física – Universidade de São Paulo
RIBEIRAO PRETO - BRAZIL
Objective
Introduce the MEPHunter software considering some technical details, applications and its applicability,
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1. Introduction
2. Development of MEPHunter
3. Applications
4. Ongoing studies in Biomag Lab
Topics
Neurophysiological recordings
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Electroencephalography
Electrocardiography
Electromiography
Magnetoencephalography
Intra and extracellular recordings(e. g. single-unit recording, patch clamp)
http://www.psychologie.uzh.ch/
http://en.wikipedia.org/wiki/Electrocardiography
Gibson et al. (IEEE Sig Proc Mag, 2012)
Baillet et al. (IEEE Sig Proc Mag, 2001)
What is “Signal Analysis”?
Definition: It is the translation of measured data into quantities to be used as descriptors of certain object of study.
Wide range of applications: biomedicine, general physics, engineering, etc.;
Case specific;
Intermediated by many commercial and free software.
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Example of signal analysis and visualization
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http://caminhodoscristais.blogspot.com.br/
Wikimedia Commons
Clark, et al. (Manual of Remote Sensing, 2001)
Spectroscopy of Rocks
What we are used to?
Commercial software
Practical and easy to use;
Limited communication with hardware and limited applications.
Most of commercial software are expensive considering research environment.
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www.otbioelettronica.itwww.neurosoft.com
What we are used to?
“Home-made” scripts
Good for limited amount of data and limited number of information to be extracted;
Fast;
Difficult to manipulate data and results;
No graphical user interface.
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DATA
RESULTS
SCRIPT
What if we need to fix errors and change selections for each case?
Impossible to do that with commercial software!
Fixing “home-made” scripts require code editing for each case.
Time-consuming and need of programming knowledge
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Silva et al. (Unpublished data, 2014)
SOLUTION!
Development of a software with the following features:
Free of charge;
Graphical user interface that allows interactions with automatic calculations;
Easy addition of new features;
Full interpretation of data exported from many hardware.
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MEPHunter
Development started in 2011;
Language MATLAB v 7.8 (MathWorks, Natick, USA);
Main purposes:
Create a graphical user interface to signal visualization
Develop algorithms to extract desired information
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Development structure
Object oriented programming
Independent modules:
Easy organization
Simplified structure
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Mód
II
Mód
III
Mód
IV
Mód
V
Mód
...
Mód
I
Development structure
One main interface to group the independent modules:
Easy to create and embody new modules;
Easy to fix errors.
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SIMILAR TO A PLUG-IN!
MEPHunter Main Interface
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MEPHunter Main
Myosystem
www.datahominis.com.br/myosystem/
OT Bioelettronica
www.otbioelettronica.it
Search Coilwww.chronos-vision.de
Biopac
http://www.usc.es/pcc/en/laboratorio.php
Visualization
MEPHunter Main Interface
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Pre-processing
Exporting
Processing
MEPHunter Main
Applications
1. TMS + EMG analysis
2. TMS pulse analyses
3. General EMG studies
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sEMG
MEP
LatencyAmplitudeMotor
Cortex
Innervation Zone
Muscle Fibers
Motor Nerve
Propagation of MEPs
TMS Principles19
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TMS + EMG analysis
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0°
180°
270°
135°
90°
45°
225°
315°
LEFT RIGHT
61 electrodes grid (13 x 5)
8 stimulation angles
TMS pulse analysis
Measurement of magnetic pulse generated by TMS coils for quality control.
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TMS pulse analysis
Measurement of magnetic pulse generated by TMS coils for quality control.
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Other sEMG analysis
Easy manipulation of automated markers selection.
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Silva et al. (Unpublished data, 2014)
InVesalius Navigator
InVesalius Navigator - neuronavigation software
Python language, freeware, open-source
Translated to 8 languages
Interface for medical images manipulation
Connection with 4 models of spatial tracker
3D Instruments tracking
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InVesalius Navigator
Measurement of distances and mapping of structures withbiomodels;
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InVesalius Navigator
Accurate spatial localization of stimulation sites
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New TMS coils for small animals
Development of small coils for more focused stimulation in animals
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TMS coil magnetic field mapping
Development of techniques for a fast magnetic field mapping of TMS coils
MRI images?
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Funding Agencies
Acknowledgments
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Prof. Dr. Oswaldo Baffa Dr. André Peres Leonardo Rakauskas
InVesalius Navigator Contributors
Dr. Jorge Vicente Lopes Renan Hiroshi
Eduardo Rodrigues Thiago Moraes
Paulo Amorim