Author Archives: Wouter Serdijn

BioCAS 2013 in Delft or Amsterdam?

Looking back on a successful BioCAS 2010 in Cyprus, the BioCAS Steering Committee is gradually looking forward to bids to host BioCAS 2013. Looking at the activities in the Netherlands by companies, such as Medtronic, Philips Healthcare, Twente Medical Systems, a.o., and academia in the Medical Delta, viz. Erasmus University Rotterdam, Leiden University and Delft University of Technology, the recent Dutch Innovative Medical Devices Initiatives and of course our own activities in the field of Biomedical Electronics, I think hosting BioCAS 2013 in Delft or Amsterdam would be great! I am currently ramping up the first discussions on this with prospective members of my organizing team.

One thing that we, unfortunately, cannot beat is the very fine weather we encountered at Cyprus. See the picture below of Cees-Jeroen, Mark, Marijn and Wannaya enjoying lunch at BioCAS 2010 in the bright sun. On the other hand, the Netherlands have lots of other good stuff to offer and usually the weather isn’t too bad in November. So stay tuned, to hear more about whether and how these plans come to fruition.

BioCAS 2010

Wouter

Neuropod: the podcast of Nature on Neuroscience

neuropodIf you, just as many members of the Biomedical Electronics Group, have a fascination for the intricacies of the human brain, you may be interested in this podcast from Nature: Neuropod.

Particularly interesting is the feature of January 2011, on why music is so pleasurable, or to find out how to treat tinnitus

Wouter

Radio silence on weblog

Dear all,

As you have noticed, not much has been posted to this weblog recently. This is most likely because most of the active bloggers of the Biomedical Group are also musicians in the ELCA band and this is the "silence before the storm", so to speak. As already announced in June’s post, the ELCA festival is upon us in (now) less than a week!

Another reason of the radio silence is due to the earthquake and successive tsunami in Japan, followed by another earthquake. Everybody held his breath when Mother Earth rumbled.

Wouter

Are Americans extraterrestial life forms?

we're not aloneTwo news items caught my attention today. The first one was the news that NASA researchers (albeit in the Journal of Cosmology) have discovered the remains of extraterrestial life forms in meteorites. The second one was that only one (1) out of almost 2000 (!) Americans fulfills all seven criteria of having a healthy human heart. Am I the only one that sees the connection?

The pressure to publish creates many victims a day

Today’s headlines of Science report that a former researcher at the renowned Massachusetts Institute of Technology has been convicted of fraud for fabricating and falsifying data. Recently a well-respected German politician copied about 50% of his PhD thesis without giving proper credits to the author(s) of the original work. He had to return his degree and resigned from the government.

plagiarism

As Editor-in-Chief of IEEE’s Transactions on Circuits and Systems-I, I receive every month a socalled "Prohibited Authors List", indicating authors that have been found guilty of plagiarism or other improper scholarly behavior and that are no longer allowed to publish in one or more IEEE journals. Unfortunately, this list is growing every month.

So, what is driving these scientists to commit fraud or plagiarism? In many cases I believe it is career pressure, as received from employers, peers, colleagues, funding agencies, or even from the researchers themselves. Of course, every scientist is responsible for his own deeds. However, the fact that the pressure may also be coming from outside means that others or other bodies can become partner in crime, too.

First of all, there is the supervisor of young PhD students, who, busy as they may be, force their young pupils to submit manuscripts to journals and conferences and inform them that the degree can only be awarded if they have at least two publications in an internationally recognized journal. There are quite a few universities that even require MSc students to have an IEEE publication before they can graduate for their MSc studies.

Second, there are the employers of (academic) staff members, who, busy as they may be, no longer seem to have the time or no longer spend enough time to properly evaluate the quality of the work conducted and thus offload their responsibility of evakuating to a number of anonymous reviewers who may or may not recommend the work be published. Often it is the number of publications that count more than their real impact.

Third, there are the funding agencies. I have evaluated a lot of project proposals over the past couple of years and one aspect to grade the applicants on is their past performance and reputation. If I have been working in the field myself, then this is a piece of cake, as I know the impact of the work conducted by my peers, at least to a certain extent. However, if you are a member of a jury that decides on, e.g., 20 project proposals of which maybe only one or two are in your field of expertise, then what do you do? I bet most people then resort to counting the number projects and publications with incomprehensible names and titles.

At Delft University of Technology, for a long time a large portion of the amount of funding professors, section heads, department heads and deans would receive from the university’s "1st money stream" depended on, indeed, the number of publications, the number of pages published and the (sometimes perceived) impact factor of the journal. I figured that if everybody at our university would only publish 50% of what he published the previous year, nothing would affect the amount of money received per faculty, department and section and this extra time could be well spent on writing better papers, performing better research and offering better education. Or on just going home on time at the end of the day for once.

Before I sign off, I would like to address young MSc and PhD students. I very well remember a case that I got involved in as editor-in-chief, in which a young, bright, PhD student abroad committed plagiarism. The plagiarism was discovered after the publication was made and, in line with procedures prescribed by the IEEE, I installed a committee to investigate the case and to decide on which sanctions should be applied. When I confronted the young author and his co-authors, of whom two were his supervisors, with the allegation made, the supervisors closed ranks immediately and blamed the PhD student for everything that had gone wrong. Despite my correspondence with the authors and expressing my viewpoint that I held also the supervisors resonsible for what had happened, in the end, the PhD degree was never awarded and the PhD student lost his appointment. I am pretty sure the professors are still there!

So my advice to everybody that is in the process of writing his first major journal paper or conference contribution is the following: please familiarize yourself with the ethical code of conduct of your organization and the publisher. For the IEEE, this code of ethical conduct can be found in IEEE’s Code of Ethics and the IEEE PSPB Operations Manual. In case of doubt, always touch base with your supervisors and/or the editor-in-chief of the journal or technical program chair of the conference you would like to submit your manuscript to. They are there to help. I know one author that contacted me well before he submitted his manuscript. By informing him of the possible consequences of his "reuse of phrases crafted by somebody else", I could prevent him from making a serious mistake by mistake and, fortunately, he still has a bright career ahead of him.

Wouter

Today, three Masters of Science in Electrical Engineering graduating from the Biomedical Electronics Group

Today is graduation day, at least for three members of the Biomedical Electronics Group, who will be awarded the degree of "Elektrotechnisch Ingenieur", or the Master of Science degree in Electrical Engineering as it is called in English. They are Gaurav Mishra, Hossein Tajeddin and Mark Stoopman. If you read this blog on time and if you are around, please join in the official ceremony at 13:00 hrs in lecture theater Ampere of the EWI building, or join us about 90 minutes later in the Pub to congratulate the newborn ingenieurs with their well-deserved title.

Wouter

Fry in your brain, or fryin’ your brain

Yesterday, I watched a very impressive two-part television documentary made by Stephen Fry, entitled "The Secret Life of the Manic Depressive" and filmed in 2006. The documentary is about his struggle with manic depression, which he prefers to call "bipolar disorder" as this is its official name and definitively does not involve a state of continuous depression. Bipolar disorder is often treated with mood stabilizing medications and, sometimes, other psychiatric drugs. However, these are not always effective and often cause a lot of side-effects.

The second part of the documentary is about Stephen wondering whether he should consider taking drugs or other kinds of psychiatric treatment, as it looks like his symptoms are getting worse over time. So in this part he visits a few people he knows and that have also been diagnosed with bipolar and are using some form of therapy. Among them is Andy Behrman, also known as "Electroboy". According to his website www.electroboy.com, "after two unsuccessful years of experimenting with all different combinations of medication to stabilize his wild mood swings, he opted for intensive bouts of electroshock therapy," [Ed.] also known as "electroconvulsive therapy", or ECT in short, "as a last resort. He was temporarily cured."

Electroshock therapyThis, of course, brings back memories of one of the famous scenes of the movie "One flew over the cuckoo’s nest", in which Jack Nicolson rallies the patients of a mental institution together to take on the oppressive Nurse Ratched, a woman more a dictator than a nurse. He finally receives ECT to calme him down. As you can see from the picture at left, the applied ECT therapy used to be quite agressive, leading to brain convulsions and seizures or even memory loss, and has therefore been classified as "high risk" by the American Food and Drug Administration, or FDA for short.

Coincidentally, the American Psychiatric Association recently stated that the FDA should move the procedure to a medium risk state as they believe the current devices are not as brute force as their older siblings. Opponents, however, state that ECT may lead to memory loss and all sorts of other complications. If you want to decide for yourself, please check out the following YouTube movie: http://www.youtube.com/watch?v=zYl13Relzbs.

My personal opinion is that, though the doctors try to do a professional job, the applied therapy is not very patient specific and the majority of parameters are determined purely on a trial-and-error basis. Adding this to the fact that ECT is not the primary therapy, but merely serves to evoke a seizure (like you have during an epileptic insult), which is the actual therapy, makes me wonder whether there aren’t any prospects of developing a better therapy, which is better tailored to the disorder at hand and, of course, better to the patient.

Anyway, this was my sermon for the late Monday morning. If you are interested in watching "The Secret Life of the Manic Depressive", just let me know and I’ll see what I can do.

Wouter 

Rats go wireless in an analog fashion

Rat carrying wireless systemThis little image on the left shows a rat carrying a wireless system, partly mounted on his head, partly realized as a kind of a backpack. It has been developed by researchers at Harvard University in close collaboration with colleagues at California Institute of Technology and is being used for neurological research on rats in the wild. According to Nature (Febr. 25, online) the entire systems comprises "a tetrode microdrive, for chronic positioning of electrodes in the brain; an integrated circuit for high channel-count neural recordings; and a radio-frequency wireless transmitter. The device takes up to 64 analog voltage signals from neurons in the brain and muliplexes them into one signal that appears in a temporally interleaved fashion, one after the other. Then that signal is transmitted by analog FM radio to a receiver."

The article further reports that good old FM (frequency modulation) transmission has been used as it outperforms digital wireless communication on weight, power drain, throughput and distance.

So why does analog FM outperform its digital counterparts, such as FSK, QPSK, QAM and OFDM? Before answering this question it is important to realize that from a channel-capacity perspective (as defined by Shannon) there is no preference for analog modulation over digital modulation. The answer thus has to follow from practical considerations. Digital modulation implies that the information is transmitted over the wireless radio channel in a digital fashion. As all information in nature, also neural signals are analog in nature and thus, in order to prepare the neural signals for their wireless journey, they have to be converted to the digital domain by analog-to-digital conversion (ADC). This thus requires at least one ADC. Often, depending on the digital modulation type used, channel coding is performed prior to the digital modulation. As a consequence, with these additional blocks, the entire transmitter becomes more complex, which, in turn, entails a larger power consumption and, when battery-operated, a larger battery and thus a larger weight on the head or back of the rat.

Another reason why analog FM may outperform its digital counterparts lies in the frequency spectrum of the transmitted radio signal. FM produces an almost flat frequency spectrum. As a consequence, it is relatively immune to frequency-selective fading, which is good for radio communication over relative long distances. Also, FM transmission does not require a highly linear power amplifier. This is good for its power efficiency and thus for the overall energy efficiency of the transmitter.

One final remark. From the picture it looks like the rat is loaded with a transmitter that has been implemented using discrete components, rather than with a single chip (or integrated circuit, IC). Many of the blocks needed for digital transmission could be implemented with a much smaller form factor and consuming less power when realized on-chip, rendering the antenna the largest component and the largest power consumer. In such a case the choice for either analog or digital could have just as well turned upside down.

Wouter

Cell phones affect the glucose concentration in the brain close to the antenna

The Journal of the American Medical Association will soon publish an article on the effects of the use of a cell phone on the glucose concentration in the region of the brain close to the antenna. According to the Preliminary Communication published today, the brain cells exposed to 50 minutes of radiation from the cell phone had a significant increase in their glucose metabolism of about 7 percent. Its clinical significance, however, is yet unknown.

Though I understand the clinical study conducted and the scientific method applied, there are some comments that I would like to vent.

The first one is about the state of the mobile phones used. The article mentions that they were on for 50 minutes. But what does "on" mean exactly? Were they just on standby, waiting for a call? Was a call being made? If so, for how long? Was there any data passed between the cell phone and its base station? But the total "talk time", or better, transmission time, is not revealed in the article.

Moreover, its is known that the amount of power transmitted by the cell phone depends on the distance to the base station. Fortunately, the cell phone decreases its output power when channel conditions are good enough, thereby extending its talk time and reducing co-channel interference. This thus implies that the amount of radiated power is another unknown in this study.

Finally, and this becomes evident from a literature study and experiments conducted by our own Mark Stoopman, the amount of energy being absorbed by brain tissue strongly depends on the frequency being used. This, in turn, depends on the type of service (GSM, UMTS, etc.) and the provider being used. GSM 1800, for instance, in use by, e.g., T-Mobile, leads to more tissue absorption than GSM 900.

All-in-all, a lot of unknows, if you ask me.

Wouter

Would you allow your brain to drive your car?

German scientists have managed to develop a car that can be controlled by signals recorded from the brain. These signals are captured by a brain interface based on electro-encephalography (EEG) sensors, which was originally designed for gaming.

  

Click here for a video that highlights the thought-powered driving system on a trip to the airport. More information on the BrainDriver can be found here.

Currently, the system still experiences serious latency, as the brain waves first have to be analyzed, clustered and classified — I’d recommend a multi-wavelet transform for doing so — before appropriate action can be taken. It still will take a while before we really can take our hands off the wheel, sit back and imagine we’re at our destination already.