CMS and DRL

CMS and DRL for EEG electrodes

Last week, I am trying to find out what CMS and DRL in my Emotiv EPOC are. For my experiment(s), those electrodes are used reference (REF) and ground (GND) on EEG cap. From the documents, which are found or given, CMS is used as REF and DRL is used as GND. It is unknown whether that configuration is compulsory or optional.

From Biosemi website, I got good explanation about CMS and DRL.

• CMS is Common Mode Sense, active electrode
• DRL is Driven Right Leg, passive electrode

They form a feedback loop for references for Analog-to-Digital Converter (ADC) of other electrodes. The schematic of CMS and DRL from Biosemi is shown below.

Explanation of CMS and DRL from Biosemi website

In my electrical engineering view, as passive electrode, DRL is suitable for ground. CMS, as active electrode, can be treated as reference on the head. Both will perform looping to get references in ADC for other electrodes. The idea is understandable for me.

CMS & DRL. http://t.co/ngeXtbCi5C http://t.co/pan9SFjjes
— iscab.saptocondro (@saptocondro) February 4, 2014

My curiosity about CMS and DRL can be read on  my other blogs:

• PhD note on February 11th, 2014
• PhD note on February 9th, 2014
• PhD note on February 3rd, 2014 

Well, I am still hoping that my research is going in the right direction.


Bremen, 11 Februari 2014

iscab.saptocondro
Darah Juang!

How seriously is Indonesia doing research on Brain-Computer Interface?

My previous blog post is about Brain-Computer Interface (BCI) research in Bandung, Indonesia (1,2,3). The research is conducted in School of Electrical Engineering and Informatics (STEI) at Institut Teknologi Bandung (ITB). I know some people who has taken part in this Bandung BCI research. However, I wonder what and how are the research outcomes.

Below is the figure of literature study of EEG-based BCI between 2007 and 2011 from Hwang, et al in 2013. The paper is "EEG-Based Brain-Computer Interfaces: A Thorough Literature Survey" in International Journal of Human-Computer Interaction, 29: 814-826 (doi), from Taylor & Francis. The authors are Han-Jeong Hwang, Soobeom Choi and Chang-Hwam Im from Hanyang University in Seoul, Korea, and Soyoung Kim from University of Rochester, New York, USA.

The figure above shows the nationalities of the authors of EEG-based BCI articles between 2007 and 2011. The articles have to be indexed by Web of Science, a database provided by Institute for Scientific Information (ISI, Thompson Scientific, Philadelphia, USA). Conference abstracts and editorials are not included. So the articles are research paper, review paper, feature, brief communication, case report, technical note and chronology.

As we can see from the figure, there are no Indonesian. So Bandung BCI group have never published their research in journals, indexed by ISI. As far as I know, the Bandung BCI group also had a collaboration with the Faculty of Medicine of Universitas Indonesia in Salemba, Jakarta, Indonesia. From some conference papers I have read, Institut Teknologi Telkom (IT Telkom) in Bandung are also doing research on EEG signals processing. But universities and also research institutes in Indonesia have not published scientific articles about EEG-based BCI in reputable journals between 2007 and 2011.

I get a feeling that Indonesian researchers and scientists publish their works more in conferences than journals. #fb
— iscab.saptocondro (@saptocondro) December 5, 2013

Well, I am Indonesian, currently doing research on EEG-based BCI. I just began my PhD program this September 2013 at Carl von Ossietzky Universität Oldenburg in Germany. So I have not yet published any journal papers. I hope, as an Indonesian, I play important role in international research on Brain-Computer Interface (BCI). In the next literature review, I hope there will be at least one Indonesian and that shall be me.

OK, now I should stop blogging and doing real research. :-)


Bremen, 6 Desember 2013

iscab.saptocondro
Darah Juang!

SSVEP electrode position, on my head

Since Posterous is killed by Twitter, pictures from my blog posts about standard 10-20 system are gone. The figures are not kept  by Posterous nor sent to Blogger. So I post the pictures again, which were saved by Wordpress:

• Standard 10-20 system and me, iscab
• Standard 10-20 system and me, saptocondro

I am wearing EEG cap

The pictures are about EEG electrode placement for SSVEP-BCI, according to 10-20 system (wiki: en,de). EEG is electroencephalography, which is recording of electrical signals from scalp (wiki: en,de,id). SSVEP is steady-state visually evoked potential, which is EEG signal as a response of flickering stimuli with certain frequency (wiki: en). BCI is Brain-Computer Interface (wiki: en,de).

10-20 system for EEG electrode position

The electrode position for SSVEP BCI  is Pz, PO3, PO4, O1, Oz, O2, O9 and O10. The ground is AFz and the reference is one ear lobe, either left or right. This position is used on my master thesis (book,slide).

Bremen, 6 Desember 2013

iscab.saptocondro

P.S. Now, I am thinking about EEG electrode position, for BCI, based on motor imagery.

Ethical Questions on Brain Computer Interface, by Paul Root Wolpe

Paul Root Wolpe had a talk "It's time to questions bio-engineering" on TED.

In the talk, there are applications of Brain Computer Interface (BCI):

• Monkey controls robotic arm with brain computer interface. The monkey sits in a room watching monitor and are put on EEG electrodes. In other room, there are robotic arm and camera. The monkey can see from the monitor what happens to robotic arm in the other room through camera. First, the monkey moves his own arm and robotic arm will make the same movement. After some repetitions, the monkey stops moving his arm and the robotic arm moves with the monkey's will.
• Flies and other insects are put on a chip to their "brain". Then engineers can control the insects to fly with a remote control. Infact, engineers and scientist have made breakthrough with mammals: rats. Here animals are losing the autonomy of their bodies. There are ethical questions on consciousness and autonomy.
• Eels' brain is put in gel which is put on electrodes. This bio-electronic system is put in a mobile robot as the main controller. The robot has a sensor and wheels. The robot can move toward the light although there are no programming codes to do so. A robot which is directly controlled by brain. (My notes: other researchers in different countries have successfully use rat brain tissues, see here)

Enjoy the video:

http://www.ted.com/talks/paul_root_wolpe_it_s_time_to_question_bio_engineering.html

 

Nürnberg, 26 Februari 2012

iscab.saptocondro

 

 

Bandung Brain Computer Interface

This is a short video of Brain Computer Interface research in Bandung, Indonesia.

The research is conducted in the School of Electrical Engineering and Informatics (STEI) in Institut Teknologi Bandung (ITB).

 

iscab.saptocondro

Standard 10-20 system EEG & me

My head

standard 10-20 system of electrode placement for EEG

Some scientific papers mentioning me and Brain-Computer Interface

I had involved in Brain-Computer Interface (BCI) research for 2 years. The research was done while studying in the University of Bremen. Now I have got M.Sc. degree in Information and Automation Engineering. After the end of my master study, there have been one master thesis, one master project report and 2 scientific papers related to BCI and me.

***

The master project report

Title: Final Preparation of the CeBit Data

author: Ignatius Sapto Condro Atmawan (That's me!)

supervisors: Prof. Dr.-Ing Axel Gräser & Dr.-Ing Ivan Volosyak

year: 2009

place: Institute für Automatissierungstechnik (IAT), Universität Bremen, Bremen, Germany

about:

The master project is mainly about EEG data format in the IAT. The BrainRobot group from the IAT conducted experiments about steady-state visual evoked potentials (SSVEP) in CeBit 2008, Hannover and RehaCare 2008, Düsseldorf, Germany. Both experiments used different data formats. The project report mentions other alternatives of data format which have already been international standards or at least european ones: GDF, EDF, BDF and BKR.

Other data format which are not mentioned in the report can be found here:

• BioSig
• scientific data formats

The Master Thesis

Title: Improvement of Response Time in SSVEP-based Brain-Computer Interface

author: Ignatius Sapto Condro Atmawan Bisawarna (That's me!)

supervisors: Prof. Dr.-Ing Axel Gräser, Dr.-Ing Ivan Volosyak & Thorsten Lüth, Dipl.-Ing.

year: 2010

place: Institute für Automatissierungstechnik (IAT), Universität Bremen, Bremen, Germany

about:

This master thesis is about how to make SSVEP-based BCI in the IAT faster (but with less error). A few time series prediction algorithms are then used. There were simulation with MATLAB, programming with C++, using BCI2000 platform and doing EEG experiments with human subjects. In the end, the proposed algorithms to help IAT system detect SSVEP faster are Regression method and Kalman Filter.

***

You can send email to saptocondro@ieee.org for more information and also the pdf files of my master project report and my master thesis.

***

The scientific paper mentioning me as an author

Title: BCI Demographics: How many (and what kinds of) people can use an SSVEP BCI?

author: B. Allison, I. Volosyak, T. Lüth, D. Valbuena, I. Sugiarto, M.A. Spiegel, A. Teymourian, I.S. Condro (That's me!), A. Brindusescu, K. Stenzel, H. Cecotti & A. Gräser.

Proc. 4th International Brain-Computer Interface Workshop and Training Course.

date: September 18-21, 2008

where: Graz, Austria

pages: 333-338

The scientific paper mentioning me in the acknowledgement

Title: BCI Demographics: How many (and what kinds of) people can use an SSVEP BCI?

author: B. Allison, T. Lüth, D. Valbuena, A. Teymourian, I. Volosyak & A. Gräser

journal: IEEE Transaction on Neural Systems and Rehabilitation Engineering

date: April 2010

volume: 18

number: 2

pages: 107-116

ISSN:1534-4320

The link to this paper can be found here.

***

I hope someday I can be an author in IEEE Transactions, especially the first author.