Aside

At the annual general assembly of the Delft Research Center on ICT (DIRECT), we proudly presented one of TU Delft’s faculty flagship projects “Beethoven”. Beethoven is a technology-driven research project on electroceuticals that aims at the design of a flexible brain implant for the effective treatment of tinnitus.

Tinnitus is the perception of sound without a corresponding external sound. It is often called “ringing in the ears”. Quite a few people suffer from tinnitus, either to a minor extent (10% of the world population) or to such an extent that life becomes difficult (2% to 3%). For the latter category, quality of life is severly hampered as these patients suffer from anxiety, insomnia and often depression.

Currently, unfortunately, there is no proven treatment for tinnitus. However, it is known that quite a few patients that have been diagnosed with severe tinnitus benefit from neural stimulation or neuromodulation. A device that provides neural stimulation or modulation is called a neurostimulator.

A neurostimulator is a kind of electroceutical, viz. a device that treats patients by means of electricity. In Delft we are convinced that electroceuticals, the electrical counterparts of pharmaceuticals, will become the mainstay of medical treatment. They will become the medicine of choice for treatment of a wide range of diseases, repair lost or impaired functions and restore healthy set points in a wide array of physiological balances.

The unique angle that TU Delft takes to the development of electroceuticals is that it focuses on the use of silicon as a base material for these devices. Silicon, the second most abundant element in the Earth’s crust, is already used for many years as the material of choice for electronic transistors and other electronic elements. As such, it can be used in electroceuticals to measure electrophysiological signals from the body, to stimulate tissue and to control the implant. However, it also offers excellent possibilities for the creation of electrodes to interact with human tissue, for the creation of a Li-Ion battery foil to store the energy harvested from a silicon-based antenna, the latter which also doubles as a transmitting and receiving element for wireless communication with the electroceutical. Moreover, silicon is also nicely biocompatible.

The plan of Beethoven is thus to design a flexible cortical implant for the effective treatment of tinnitus, using a polymer as a substrate and silicon as its base material. The research groups involved at TU Delft are the Biomedical Electronics Group, the Electronic Instrumentation Laboratory, the Electronic Components, Technology and Materials Lab, Computer Engineering and the Fundamental Aspects of Materials and Energy group.

Within the Medical Delta, Beethoven collaborates with the Leiden University Medical Center and the Erasmus Medical Center. Internationally, Beethoven collaborates with the Brain Research Center Antwerp for Innovative and Interdisciplinary Neuromodulation.

While Beethoven is a project, the founding fathers of Beethoven are already thinking of establishing a national Research Center on Electroceuticals, its mission being to become a leading entity and partner in research on, the development of and education in technology of advanced electroceuticals. A proper acronym for the center still needs to be found, but already now links have been established with UMC St. Radboud, UMCU, UMCG, U Twente and various SMEs and larger enterprises that wish to become active in the field.

If Beethoven would have been alive still, this probably would have sounded like music to his ears.

New Book: EMI-Resilient Amplifier Circuits

EMI-Resilient Amplifier Circuits

EMI-Resilient Amplifier Circuits

van der Horst, Marcel J., Serdijn, Wouter A., Linnenbank, André C.

2013, XIV, 300 p. 75 illus., 1 illus. in color.

ABOUT THIS BOOK
Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers
Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements
Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detrimental effects on noise and stability
This book enables circuit designers to reduce the errors introduced by the fundamental limitations and electromagnetic interference (EMI) in negative-feedback amplifiers. The authors describe a systematic design approach for application specific negative-feedback amplifiers, with specified signal-to-error ratio (SER). This approach enables designers to calculate noise, bandwidth, EMI, and the required bias parameters of the transistors used in application specific amplifiers in order to meet the SER requirements.

· Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers;

· Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements;

· Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detrimental effects on noise and stability.

Content Level » Research

Keywords » Analog Integrated Circuit Design – EMI – EMI-resilient – Electromagnetic Compatibility – Electromagnetic Compatibility Engineering – Electromagnetic Interference – Electromagnetic Interference-resilient – Negative-feedback Amplifier Circuits – Signal-to-Error Ratio

Related subjects » Applied & Technical Physics – Circuits & Systems – Electronics & Electrical Engineering

TABLE OF CONTENTS
Introduction.- Decreasing the disturbance coupled to amplifiers.- Modelling of active devices.- The Cascode and Differential amplifier stages.- Design of EMI-resilient single-stage amplifiers.- Design of EMI-resilient dual-stage amplifiers.- Realizations.- Conclusions and recommendations.

Quote from Michael Merzenich

While reading, correcting and enjoying the essay of Jose Manuel Rosas Escobar, I stumbled on a quote from Michael Merzenich, which I think you should read and comtemplate on.
So here goes…
“The success with any complicated prosthetic device relates as much to how the brain adjusts to it, accepts it and controls its use as it does to the device itself. If we can figure out how to engage the brain to do its part, it can make a merely adequate neural prosthetic device work marvelously.”

Wouter

New Biomedical Electronics Group photo

Biomedical Electronics Group anno 2013

Biomedical Electronics Group anno 2013

Today we made a new group picture. And thus we proudly present:

The Biomedical Electronics group anno 2013. From left to right:
Wu Chi Wing, Yao Liu, Duan Zhao, Menno Vastenholt, Sophinese Iskander-Rizk, Cees-Jeroen Bes, Alexandra-Maria Tautan, Lucho Gutierrez, Wouter Serdijn, Horacio Jimenez, Marijn van Dongen, Matthijs Weskin, Senad Hiseni, Joeri Willemse, Mark Stoopman, Yongjia Li, Andre Mansano, Wannaya Ngamkham.

Not on the photo: Sumit Bagga, Robin van Eijk, Marcel van der Horst, Marion de Vlieger, Chutham Sawigun, Sander Fondse, Joeri Biesbroek

Picture taken March 6, 2013.

Marijn received best presentation award at BME 2013 Conference

The Biomedical group this year attended  the BME 2013 (the 4th Dutch Bio-Medical Engineering Conference 2013) conference, held at 24th and 25th of January 2013. Our group held 5 oral presentations (Senad, Yao, Wannaya, Wu, Marijn) and 2 poster presentations (Rico and me). Marijn was selected as one of the four nominees for the best oral presentation award. Moreover, he was not only nominated, he also won this award! Congratulations, Marijn! 🙂

Can heart beats really power cardiac pacemakers?

Baron von Munchausen

Today, I received a link (http://tweakers.net/nieuws/85353/hartslag-kan-pacemaker-van-stroom-voorzien.html) from Marijn, honorary member of the Biomedical Electronics Group, in which it is mentioned that researchers have found a way to harvest enough energy from a piezo-electric transducer so that a cardiac pacemaker can be powered from the heart itself. This would render the bulky batteries in the pacemakers unnecessary and the pacemaker thus does not have to be replaced after a couple of years because of a depleted battery.

I have two concerns about this. First, there is a kind of “Baron-von-Munchausen” effect. Baron von Munchausen was an 18th-century German nobleman, who, according to Rudolf Erich Raspe’s story The Surprising Adventures of Baron Munchausen, pulls himself out of a swamp by his hair (specifically, his pigtail). Now, let’s suppose that a pacemaker, equipped with a piezo-electric energy harvester to power the pacemaker, for no particular reason, fails to operate and the heart stops its precious beating, what will then power up the pacemaker again to make the beat again? Scary thought, isn’t it?

Second concern is of another nature. Pacemakers are usually replaced, not because the battery has depleted, but simply because a next generation pacemaker can provide a better therapy to the patient. As a side note, uncomfortable but true, current pacemakers (and thus also the batteries included therein) on average live longer than their owners. Hopefully this latter aspect will change for the better soon.

Wouter

Does enriched acoustic environment in humans abolish chronic tinnitus clinically and electrophysiologically?

Animal research has shown that loss of normal acoustic stimulation can increase spontaneous firing in the central auditory system and induce cortical map plasticity. Enriched acoustic environment after noise trauma prevents map plasticity and abolishes neural signs of tinnitus. In humans, the tinnitus spectrum overlaps with the area of hearing loss. Based on these findings it can be hypothesized that stimulating the auditory system by presenting music compensating specifically for the hearing loss might also suppress chronic tinnitus. To verify this hypothesis, a study was conducted in three groups of tinnitus patients. One group listened just to unmodified music (i.e. active control group), one group listened to music spectrally tailored to compensate for their hearing loss, and a third group received music tailored to overcompensate for their hearing loss, associated with one (in presbycusis) or two notches (in audiometric dip) at the edge of hearing loss. Our data indicate that applying overcompensation to the hearing loss worsens the patients’ tinnitus loudness, the tinnitus annoyance and their depressive feelings.
No significant effects were obtained for the control group or for the compensation group. These clinical findings were associated with an increase in current density within the left dorsal anterior cingulate cortex in the alpha2 frequency band and within the left pregenual anterior cingulate cortex in beta1 and beta2 frequency band. In addition, a region of interest analysis also demonstrated an associated increase in gamma band activity in the auditory cortex after overcompensation in comparison to baseline measurements. This was, however, not the case for the control or the compensation groups. In conclusion, music therapy compensating for hearing loss is not beneficial in suppressing tinnitus, and overcompensating hearing loss actually worsens tinnitus, both clinically and electrophysiologically.

2012 Published by Elsevier B.V, in Hearing Research, Hear Res. 2012 Oct 23. pii: S0378-5955(12)00244-4. doi: 10.1016/j.heares.2012.10.003. Authors: Vanneste Svan Dongen MDe Vree BHiseni Svan der Velden EStrydis CKathleen JNorena ASerdijn WDe Ridder D

Neurostimulation causes nerves cells to grow back and allows paralyzed to walk again

Article from De Volkskrant, dd. Oct. 27, 2012, entitled "Paralyzed walks again"

Article from De Volkskrant, dd. Oct. 27, 2012, entitled “Paralyzed walks again”

Eddy was damn right when after the disk in his spinal cord was removed by the neurosurgeon and he lost almost all the feeling in one of his legs due to the acute hernia. By means of transcutaneous stimulation of his foot and leg he was able to regain feeling and control over his muscles  and walk again. The method was not proven scientifically yet, but obviously worked, as we witnessed from closeby. Now the scientific proof is there.

Exciting times ahead, if you ask me.

Wouter

Article in “De Telegraaf”, September 29, 2012 (in Dutch)

Artikel Telegraaf

Wouter

We have migrated!

Dear readers of and contributors to the Biomedical Electronics weblog: we have now migrated to WordPress. This rather smooth handover has been completed yesterday and has resulted in a new look, but most importantly, a better user interface. Please try it out for yourself! I look forward to seeing your fine contributions coming in. Also if you have suggestions for the look and feel of the weblog, please do not hesitate to contact me.

As a noteworthy fact, this month one of our contributions reached 10,000+ views.

Best regards,

Wouter