Author Archives: Wouter Serdijn

In case you’ve just missed it…

Posted on 30/06/2011 | Leave a comment

Fixing the Brain-Computer Interface

Researchers are addressing the sizable population for whom
BCI doesn’t work

By Erica
Westly  /  June 2011

New website (in Dutch): http://www.braininnovations.nl/

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It takes some cooking to prepare a good meal

Posted on 24/06/2011 | Leave a comment

Frequent readers of this weblog may have started to wonder whether the activities of the Biomedical Electronics Group have gradually fainted and dissolved in eternity, its members have all become hobos and it all ended in a big dream. Bzinga. The truth is, of course, that everybody is very busy and under the yoke of some deadline or another.

Senad and June been working very hard on a first proof-of-principle of a Tinnitus detector circuit. Such a circuit should allow for detection of the spatial properties of tinnitus and give objective information on its severity. This could, in turn, lead to more refined or adjusted stimulation therapies. Don’t sell your mother for it, yet, but expectations are high. The findings will be worked out in a manuscript, to be submitted to the annual BioCAS Conference today.

On the detection side of things, Yongjia has been working very hard on the new type of level-crossing analog-to-digital converter, described in an earlier weblog. Also this work will be submitted to the BioCAS Conference.

Duan Zhao received the good news that our paper (together with the Holst Centre) on a reconfigurable subsampling receiver has been accepted for presentation and publication at the PIMRC Conference in Toronto. Congratulations. He just returned from a visit to his home country and we’re happy to have him back again.

Of course there is more that can be reported, such as the coming ELCA day trip, the preparations for organizing BioCAS 2013 in Delft, the IMDI NeuroControl, more power-efficient neurostimulation circuits, higher-efficiency RF energy harvesting circuits, June’s paper that got accepted in Transactions on Circuits and Systems-I: Regular Papers (congrats, too), Sandro’s and Senad’s paper that enjoyed the same fate (congrats, too), STW Perspectief and how the Dutch Ministries of Economical Affairs, Agriculture and Innovation and of Health, Wellbeing and Sport have no clue on how to increase valorization in the Netherlands (as witnessed yesterday at the MedTech West Event), but this would make good stuff for another blog. So stay tuned!

Wouter

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Dutch documentary on the Mystery of the Brain (6 episodes)

Posted on 28/05/2011 | Leave a comment

BreingeheimLast Tuesday I saw an excerpt of an interesting episode on Dutch television about what happens with the human brain when it ages and in particular what happens with it in the unfortunate situation of Alzheimer’s disease. This episode, presented by the well-known and charming Dutch news presenter Charles Groenhuijsen, in fact is part of a larger series that tries to shed some light on what happens in this 1.5kg human organ that is at the base of all our thoughts, actions, emotions, etc., of which its intricacies and inner workings are still a mystery to us. 

The complete series (in Dutch) can be viewed from Uitzending Gemist and also from the following link of Omroep Max: http://www.maxbreingeheim.nl.

Highly recommended!

Wouter

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Posted in General, Understanding the Brain

“And the paralyzed will walk again”

Posted on 22/05/2011 | 2 comments

With this promising statement of Michio Kaku ends a video cut that I made from a TV documentary entitled "2057 The Body" and which I use inside a presentation on wearable and implantable medical devices. The documentary predicts that in the year 2057 we will be able to inject tiny wireless sensors and actuators inside the body thereby restoring the connectivity of the peripheral nervous system and be able to use our senses and control our muscles again.

Last week, still 46 years away from the year 2057, it was reported in the Lancet that [from the UCLA Newsroom] "a team of scientists at the University of Louisville, UCLA and the
California Institute of Technology has achieved a significant breakthrough in
its initial work with a paralyzed male volunteer at Louisville’s Frazier Rehab
Institute — the result of 30 years of research to find potential clinical
therapies for paralysis.

The man, Rob Summers, 25, was completely paralyzed below the chest after
being struck by a vehicle in a hit-and-run accident in July 2006. Today, he is
able to reach a standing position, supplying the muscular push himself. He can
remain standing, and bearing weight, for up to four minutes at a time (up to an
hour with periodic assistance when he weakens). Aided by a harness support and
some therapist assistance, he can make repeated stepping motions on a treadmill.
He can also voluntarily move his toes, ankles, knees and hips on command.
 
These unprecedented results were achieved through continual direct
"epidural electrical stimulation" of the subject’s lower spinal cord, mimicking
signals the brain normally transmits to initiate movement. Once that signal is
given, the research shows, the spinal cord’s own neural network, combined with
the sensory input derived from the legs to the spinal cord, is able to direct
the muscle and joint movements required to stand and step with assistance on a
treadmill.
 
The other crucial component of the research was an extensive regime of
locomotor training while the spinal cord was being stimulated and the man
suspended over the treadmill. Assisted by rehabilitation specialists, the man’s
spinal cord neural networks were retrained to produce the muscle movements
necessary to stand and to take assisted steps.

[…]

Relief from secondary complications of complete spinal cord injury —
including impairment or loss of bladder control, sphincter control and sexual
response — could prove to be even more significant.
 
"The spinal cord is smart," said Edgerton, distinguished professor of
integrative biology and physiology and of neurobiology at UCLA. "The neural
networks in the lumbosacral spinal cord are capable of initiating full
weight-bearing and relatively coordinated stepping without any input from the
brain. This is possible, in part, due to information that is sent back from the
legs directly to the spinal cord."
 
This sensory feedback from the feet and legs to the spinal cord facilitates
the individual’s potential to balance and step over a range of speeds,
directions and levels of weight-bearing. The spinal cord can independently
interpret these data and send movement instructions back to the legs — all
without cortical involvement.

[…]

More than 5 million Americans live with some form of paralysis, defined as
a central nervous system disorder resulting in difficulty or inability to move
the upper or lower extremities. Roughly 1.3 million are spinal cord injured, and
of those, many are completely paralyzed in the lower extremities.
 
Epidural stimulation, in the context of paralysis of the lower extremities,
is the application of continuous electrical current, at varying frequencies and
intensities, to specific locations on the lumbosacral spinal cord corresponding
to the dense neural bundles that largely control movement of the hips, knees,
ankles and toes. The electrodes required for this stimulation were implanted at
University of Louisville Hospital by Dr. Jonathan Hodes, chairman of the
department of neurosurgery at the University of Louisville.

[…]
 
For a more in-depth discussion of the research behind the breakthrough,
watch this interview with
Edgerton." 

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Posted in General, Neurostimulation and Neuromodulation

STW project ReaSONS approved!

Posted on 20/05/2011 | 2 comments

Today I received some good news by means of a phone call of Wouter Segeth, program officer with STW, the Dutch Technology Foundation. Our ReaSONS project (Realtime Sensing of Neural Signals), a collaboration between Delft University of Technology and Leiden University Medical Center has been approved.

The project aims at the realtime recording of the evoked compound action potential (ECAP) generated by the haircells in the cochlea while fitting a cochlear implant. Also it is considered to be one step towards the creation of realtime online closed-loop neurostimulators.

This is of course good news for Cees-Jeroen, upcoming PhD student in the BME group, who supposedly will start his duties in September this year. 

Wouter

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User permissions changed

Posted on 20/05/2011 | Leave a comment

The regular contributors to this blog have received a free upgrade. By becoming a Publisher rather than a Contributor, I hope we will be able to serve the readership in a more timely manner. Check it …

(W)out

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Unexpected Meet and Greet with Hero in Circuit Theory

Posted on 08/05/2011 | Leave a comment

Georg Simon OhmLast week, I was in Köln, Koeln, Keulen or Cologne (depending on from which country you are) with my family and while on our way to the Dom, Cologne’s well-known cathedral, I bumped into one of the greatest heroes of electric circuit theory: Georg Simon Ohm. The sign says that "George Simon Ohm discovered, in this house, being a teacher at the Old Gymnasium in Cologne, in 1826, the foundation of electric current."

Though one of the most important discoveries indeed, I think it is not so much the discovery of the foundation of electric current, but rather the relation between voltage and current that holds for linear resistances (and impedances, in the harmonic regime), later known as "Ohm’s Law" that caused his name to be remembered forever.

For those that have both an interest in technology and law, I cordially recommend Ohm’s Law and Kirchhoff’s Laws as basic study material.

Wouter

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Posted in Education, Electronics, General

Making music keeps the brain fitter

Posted on 22/04/2011 | Leave a comment

On http://esthenews.org/tag/brenda-hanna-pladdy/ we can read the following:

"The Tiger Mothers were right all along: Music lessons as a kid may make you a sharper grown-up.

A new study finds that older adults with musical experience perform better on some cognitive tests than those who had never studied music. With only 70 participants, the study was small, but the results match those from other studies of challenging tasks, including findings that learning a second language protects against dementia.

no music no life"Musical activity throughout life may serve as a challenging cognitive exercise, making your brain fitter and more capable of accommodating the challenges of aging," study researcher Brenda Hanna-Pladdy, a neurologist at the Emory University School of Medicine, said in a statement. "Since studying an instrument requires years of practice and learning, it may create alternate connections in the brain that could compensate for cognitive declines as we get older."

[…]

"Whether the participant continued to play music into old age didn’t matter, the researchers found. Instead, long-term study in youth seemed to confer benefits far down the road."

The entire scientific article can be found at: http://www.apa.org/pubs/journals/releases/neu-25-3-378.pdf.

This is, of course, good news for those involved in the ELCA Music Festival, all of them who speak a second language (often English) and took up making music in their childhood, or, like Senad, inspired by the ELCA Festival, are currently taking up music lessons. Gradually I start looking out for the next edition…

Wouter

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Posted in General, Understanding the Brain

Programmable Implants

Posted on 21/04/2011 | 2 comments

This article originally appeared in Delta, April 13, 2011. By Thomas van Dijk

For his PhD research, Dr Christos Strydis rethought the architecture for processors in biomedical implants.

In future implants might be recharged by the brain. (Photo: Ana Laura Santos)

Saying that they are committed to their research into neurostimulation is an understatement. In their quest to develop a treatment for patients with tinnitus, a syndrome where people hear phantom noises, Professor Dirk De Ridder, a neurosurgeon and neuroscientist at  University Hospital Antwerp, and assistant professor Eddy van der Velden, a medical researcher at Antwerp’s Monica hospital, are about to be operated on themselves. During an experiment to be held at the end of this month, the professors will have wires sticking out of the back of their heads, through which electrical pulses will travel to their brains. 

“They are really crazy,” says computer engineer, Dr Christos Strydis, laughing. In his office, Dr Strydis shows an application on his smart phone. With this app he will command the device – which is the size of a packet of cigarettes – that is attached to the guinea pig professors and generates the pulses. Depending on the frequency of the pulses, the test subjects might feel energetic, euphoric or sleepy, to name but a few of the possible states. 

Strydis is part of a large team of researchers from the faculties of Electrical Engineering, Mathematics and Computer Science, and Applied Sciences, who over the years have been working with the Belgian medics on biomedical implants. The team’s goal is to develop tiny, low-energy consuming implants that can be controlled by software, rather than being based solely on hardwired circuits. 

Strydis has been focusing on the type of processor needed for such devices. Last month he defended his PhD thesis, titled ‘Universal processor architecture for biomedical implants.’

Strydis believes that it’s time for a paradigm shift in the field of biomedical implants: “One big problem is that the electrical signals created by implants no longer aid patients with neurological diseases after a certain period of time, because the body simply gets used to the signals and ignores them. So the device should be smarter and more flexible. You should be able to programme it. What’s more, every patient is different, so standard implants with standard signals do not work optimally for everyone.”

It will take at least another five years before the device built by the Delft researchers will be miniaturised enough to be placed directly under the skull of patients, Strydis surmises. Neuroscientist Prof. van der Velden hopes that the battery inside the implant, which ultimately must work at a voltage of no more than half a millivolt, will be recharged by the brain. 

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Posted in General, Neurostimulation and Neuromodulation, Understanding the Brain

About impact factor, freedom trails and electrology

Posted on 11/04/2011 | 1 comment

Dear reader,

Though I have tried to be virtually present as much as possible, I am currently neither in Delft nor in my hometown Leiden. This also explains the late hour of this post. Where I am, it is currently a little over 6 pm. I am in Medford, a small forensic town near Boston, MA, USA. The main reason for being here is twofold. First, as Editor-in-Chief (EiC) of the IEEE Transactions on Circuits and Systems-I, I participated in the annual IEEE Panel of Editors (PoE) meeting. Second, I am here to give an invited talk at Tufts University in a seminar hosted by Prof. Sameer Sonkusale.

During the PoE meeting, we discussed a lot about good and not-so-good EiC practices, about upcoming changes to IEEE Xplore, about plagiarism (which, unfortunately, becomes more of a problem), about journal performance metrics, etc. The latter is also very important to you. That is, if you (plan to) make scientific, design and engineering contributions and you (plan to) present them in a journal or at a conference. And if they contribute to your reputation as a researcher, scientist, designer or scholar. For this, our busy chairs, heads and leaders, more and more resort to the only thing they understand about your work, being "the number"; more specifically, the Impact Factor (IF). I will not bother you with the exact definition of IF; many people do not even know and don’t care, your boss probably included, but it is generally considered to be a measure to express your importance, or the importance of your publications, or the importance of the journal that you publish your work in. Whereas it purely counts incoming citations without considering the significance of those citations.

ethicsSince the algorithm for computing the impact factor is simple, it is also simple to manipulate. And this is exactly what is being done constantly, by authors, who for this reason include a lot of self-citations in their manuscripts, and by journals that impose a lot of self-citations (to the journal) on their authors. Since this is seriously blurring the reputation of people and journals, but also the minds of our evaluators, more objective figures-of-merit have been discussed, the most elegant one probably being the Article Influence. If you are interested you may wish to (and if you are a boss of a scholar or a scholar yourself, you probably should) check out http://www.eigenfactor.org/.

After the PoE meeting, I took off for a walk in and around the city center of Boston, called The Freedom Trail. See http://www.thefreedomtrail.org/. The Freedom Trail was recommended to me by Menno (as of now honorary member of the BME group) and, according to the web site, is "a 2.5 mile red-brick walking trail that leads you to 16 nationally significant historic sites, every one an authentic American treasure." And indeed it did. And I believe it also guides you through some of the most beautiful places in Boston. If you ever happen to be around, check it (and the Guinness from one of the Irish pubs) out!

Today I changed hotels and I am currently in Medford, where I will be staying for the coming two days, as tomorrow and the day thereafter I will meet various students, professors, heads and deans of Tufts University and give two presentations on Electronics for Wearable and Implantable Medical Devices, discuss possible opportunities for collaboration and discuss some latest research results that both Sameer Sonkusale’s group and the one of yours truly are working on.

So what about electrology, then? Well, today I went for a walk in the town of Medford and I came across a sign that advertises the services offered on 82 Forest St. Among them those of an Electrologist. So what does he or she do? Well, the sign reads on with the name of the therapist (which I will not disclose here) and the name of his shop: "Hair it go’s!" The service? Permanent Hair Removal. So if you ever wonder whether I may be getting bold, don’t you dare. Signing off with a famous phrase of Senad: "The things we do for science…."

Wouter

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