mephunter: making things easier for signal visualization and analysis

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,

27-Nov-14VICTOR HUGO SOUZA

2

1. Introduction

2. Development of MEPHunter

3. Applications

4. Ongoing studies in Biomag Lab

Topics

1. Introduction


3

Neurophysiological recordings


4

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.


5

Example of signal analysis and visualization


6

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.


7

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.


8

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


9

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 (Unpublished data, 2014)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.


10

2. Development of MEPHunter


11

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


12

Development structure

Object oriented programming

Independent modules:

Easy organization

Simplified structure


13

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.


14

SIMILAR TO A PLUG-IN!

MEPHunter Main Interface


15

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


16

Pre-processing

Exporting

Processing

MEPHunter Main

3. Applications


17

Applications

1. TMS + EMG analysis

2. TMS pulse analyses

3. General EMG studies


18

sEMG

MEP

LatencyAmplitudeMotor

Cortex

Innervation Zone

Muscle Fibers

Motor Nerve

Propagation of MEPs

TMS Principles19


TMS + EMG analysis


20

0°

180°

270°

135°

90°

45°

225°

315°

LEFT RIGHT

61 electrodes grid (13 x 5)

8 stimulation angles

TMS + EMG analysis


21

TMS + EMG analysis


22

TMS + EMG analysis


23

TMS + EMG analysis


24

TMS pulse analysis

Measurement of magnetic pulse generated by TMS coils for quality control.


25

TMS pulse analysis

Measurement of magnetic pulse generated by TMS coils for quality control.


26

Other sEMG analysis

Manual identification of triggers.


27

Other sEMG analysis

Manual identification of triggers.


28

Other sEMG analysis

Easy manipulation of automated markers selection.


29

Silva et al. (Unpublished data, 2014)

4. Ongoing studies in Biomag


30

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


31

InVesalius Navigator32

Mapping of stimulation sites;



Measurement of distances and mapping of structures withbiomodels;

33


InVesalius Navigator34

Registration and tracking of instruments;



Accurate spatial localization of stimulation sites


35

New TMS coils for small animals

Development of small coils for more focused stimulation in animals

36


TMS coil magnetic field mapping

Development of techniques for a fast magnetic field mapping of TMS coils

MRI images?

37


Funding Agencies

Acknowledgments


38

Prof. Dr. Oswaldo Baffa Dr. André Peres Leonardo Rakauskas

InVesalius Navigator Contributors

Dr. Jorge Vicente Lopes Renan Hiroshi

Eduardo Rodrigues Thiago Moraes

Paulo Amorim

http://www.fapesp.br/index.php

http://www.fapesp.br/index.php

mephunter: making things easier for signal visualization and analysis

Education

mephunter software

development of mephunter

mephunter development

md v md

mephunter main interface

limited applications

free software

commercial software