Author Archives: Wouter Serdijn

Electronics in Neonatology

Bij Rico van Dongen, honorary member of the Bioelectronics Group

An Electronic Fetal Monitor, also known as cardiotocograph (CTG), to record the fetal heartbeat and the uterine contractions during pregnancy

On December first of last year I became the proud father of a baby boy, Wouter. Unfortunately, the pregnancy and birth did not go according to plan and my wife and I were exposed to a long period of hospitalization and a lot of medical devices.

It all started October last year when my wife was hospitalized with pre-eclampsia, a form of pregnancy related high blood pressure. The fact is there is no cure or proper treatment for this besides inducing labor and abort the pregnancy. Being only 25 weeks pregnant at the time the survival changes of the baby are already quite good thanks to modern neonatology, but certainly not without complications.

Obviously the best path for our unborn child was to extend the pregnancy for as long as possible and try to control the high blood pressure with medication. Two months of intensive hospital care and almost weekly increasing dose of medication followed.

The heartbeat of our baby was monitored daily by means of cardiotocography, CTG, to check if he could still handle the high dose of medication. The resulting graphs were, according to the doctors, sub-optimal. This resulted in the fact that my wife was connected to this CTG machine for up to 4 hours a day before the doctors were confident again that our baby was stable.

As a father confident in the strength of our child I soon blamed the machine for this sub-optimal picture. It was not long before we realized that almost all drops in heartbeat correlated with movement of the baby. As an engineer, my hands were itching with the urge to re-write the software of this machine and add an additional graph with signal quality to the output.

Weeks of endless CTG and blood pressure medication passed. By the time of the 30st week of pregnancy oral medication was nog longer sufficient and the real heavy stuff was administered through IV drip. Two weeks passed until there was no other option than to abort the pregnancy.

Although usually inducing labor is not successful at this early terms my wife managed to pull it off and finally our son was born. Although weighing only 1417g it was a strong guy that could already breath on his own. He spent only one night at the intensive care for observation before we could move him to the high-care section.

The good news only lasted half a day. After a routine ultrasound of the brains the doctors discovered a massive hemorrhage. His right ventricle was half filled with blood and the left completely filled. At the left side there was already sign of damage to brain tissue. The damage concentrated to the connections from the motor cortex to the central nerve system. The neonatologist explained to us that bleedings at premature born babies are not that uncommon, the strange thing about our case was that the bleeding already occurred before birth. Luckily the human brain, and especially the undeveloped brain of babies, is capable of finding new connections and avoid damaged regions.

There is a chance that we won’t be able to notice anything abnormal in the way our baby moves but it was clear that our days of worrying and hospital visits were long from over. But first things first, being only 1417g our boy needed to gain strength in an incubator.

The incubator is, again, a collection of medical electronics where the engineer in me would love to make some improvements. Take for example the electrodes used for monitoring the heartbeat and the sensor for measuring blood oxygen saturation. I’m not sure if it was the way of handling our baby but somehow the leads always seemed to be tangled. Small wireless sensors would be very helpful in this situation. Perhaps this is a good use for low power ultra-wide-band technology. On the other hand, it is nice to see the designers already took some effort making the electrodes fit in to the cuddly baby environment by printing cute teddy bear pictures on them.

Another one and a half month passed before out baby boy was strong enough to leave the hospital. As a final check an MRI was made. It clearly showed the damaged regions but also that the brains developed normal and that the remaining blood was gradually cleared away. At this point he is just like any other baby. There is nothing wrong with his ability to cry us awake during the night or to kick off his socks. Nevertheless, his development will be closely monitored with perhaps even more electronics.

I guess my messages to other biomedical engineers is first of all, keep up the good work. Until you need the electronics we design you don’t really realize how valuable our work is. Secondly, I think it would be helpful to try to evaluate the design from the viewpoint of the patients and medical personnel that are using your products.

Rico van Dongen, Febr. 6, 2016

Baby Wouter van Dongen

Baby Wouter van Dongen

Symposium: Bioelectronics meets Electrophysiology, Wednesday, 30 March 2016, 09:30-18:00 hrs, Aula Main Auditorium, Delft University of Technology, Delft

Symposium: Bioelectronics meets Electrophysiology

Wednesday, 30 March 2016

09:30-18:00

Aula Main Auditorium, Delft University of Technology, Delft

Johan Frijns (LUMC), Jeroen Dudink (ErasmusMC), Richard Houben (AB-Sys), Freek Hoebeek (ErasmusMC), Dirk Ridder (Otago Univ.)

On the occasion of Wouter Serdijn’s recent appointment to full professor in bioelectronics and the inaugural ceremony in which he accepts his appointment, a full-day symposium will be organized. This symposium addresses bioelectronics from a technological, a medical, a clinical, an industrial and a societal perspective. Five distinguished speakers from the Erasmus and Leiden Medical Centers, from the Dunedin School of Medicine and from Applied Biomedical Systems will address these challenging topics.

The symposium language will be English and free of charge. Registration is required, though. Please click the following link to register: Registration

Programme:

9:30 hrs: registration and coffee
10:00 hrs: opening of the symposium by the chairman, Dr.ir. Marijn van Dongen
10:10 hrs: Prof.dr.ir. Johan Frijns, Leiden University Medical Center, ENT Cochlear Implants: Clinical problem, technical solution and social impact
10:40 hrs: Dr. Jeroen Dudink, Erasmus Medical Center, Neonatology The future of baby brain monitoring
11:10 hrs: Ing. Richard Houben, Applied Biomedical Systems Electroanatomical Mapping of Persistent Atrial Fibrillation
11:40 hrs: coffee break
12:10 hrs: Dr. Freek Hoebeek, Erasmus Medical Center, Neuroscience Bioelectronics allow the small brain to conquer the big brain
12:40 hrs: Prof.dr. Dirk de Ridder, Dunedin School of Medicine, New Zealand Bioelectronics controls the brain by mimicking nature
13:10 hrs: lunch
15:00 hrs: inaugural ceremony and speech of Dr.ir.Wouter Serdijn, Delft University of Technology Beter worden met elektrceutica: elektronische medicijnen reiken de helpende hand 

(Eng: Getting Better with Electroceuticals: electronic medicine to the rescue)

16:30 hrs reception+

New book: Design of Efficient and Safe Neural Stimulators – A Multidisciplinary Approach

About this book:

This book discusses the design of neural stimulator systems which are used for the treatment of a wide variety of brain disorders such as Parkinson’s, depression and tinnitus. Whereas many existing books treating neural stimulation focus on one particular design aspect, such as the electrical design of the stimulator, this book uses a multidisciplinary approach: by combining the fields of neuroscience, electrophysiology and electrical engineering a thorough understanding of the complete neural stimulation chain is created (from the stimulation IC down to the neural cell). This multidisciplinary approach enables readers to gain new insights into stimulator design, while context is provided by presenting innovative design examples.

About the authors:

Marijn N. van Dongen was born in Pijnacker, The Netherlands, in 1984. He received the M.Sc. and Ph.D. degrees in electrical engineering from the Delft University of Technology, Delft, The Netherlands, in 2010 and 2015, respectively. His research interests include the design of neural stimulator output circuits as well as the modeling of the electrophysiological and electrochemical processes during electrical stimulation. Currently he is working for NXP Semiconductors, Nijmegen, The Netherlands. Dr. van Dongen served as the Financial Chair of the IEEE BioCAS2013 Conference.

Wouter A. Serdijn (M’98, SM’08, F’11) was born in Zoetermeer (‘Sweet Lake City’), the Netherlands, in 1966. He received the M.Sc. (cum laude) and Ph.D. degrees from Delft University of Technology, Delft, The Netherlands, in 1989 and 1994, respectively. Currently, he is full professor of bioelectronics at Delft University of Technology, where he heads the Section Bioelectronics. His research interests include low-voltage, ultra-low-power and ultra wideband integrated circuits and systems for biosignal conditioning and detection, neuroprosthetics, transcutaneous wireless communication, power management and energy harvesting as applied in, e.g., hearing instruments, cardiac pacemakers, cochlear implants, neurostimulators, portable, wearable, implantable and injectable medical devices and electroceuticals.
He is co-editor and co-author of 9 books, 8 book chapters and more than 300 scientific publications and presentations. He teaches Circuit Theory, Analog Signal Processing, Micropower Analog IC Design and Bioelectronics. He received the Electrical Engineering Best Teacher Award in 2001, 2004 and 2015. Wouter A. Serdijn is an IEEE Fellow, an IEEE Distuingished Lecturer and a Mentor of the IEEE.

How do you become Best Lecturer of TU Delft?

Nominated best lecturers 2015 – Wouter Serdijn (EEMCS) and Ianus Keller (IDE) – and students give a sneak peek in their way of teaching. After these tips you could become Best Lecturer 2016.

On 26th November, the Best Lecturer of the year 2015 was chosen. 8 nominees, one from each faculty, competed for the prize. But how do you ‘become’ lecturer of the year of lecturer or your faculty? How does the lecturer of the year differentiates him or herself from the other lecturers? Is the interaction with the students different and what is the ‘Golden tip’?

Read more

Intuitive CMOS transistor modeling

On Oct. 6, 2015, I gave a guest lecture in the lecture series “Structured Electronic Design” (EE4C09) on Intuitive CMOS Transistor Modeling. In there I explain the 5 regions of operation of an MOS transistor (both in weak inversion and in strong inversion, both in triode and saturation, and off), based on the EKV model. For those of you that might still be struggling with understanding how the CMOS transistor works and how it can be employed in first time right, first time best analog and mixed signal circuit design, this lecture is for you.
See the complete lecture, which also treats double loop negative feedback amplifiers, herehttps://collegerama.tudelft.nl/Mediasite/Play/d2fc417f2e644a64b4463e34322f86a31d?catalog=528e5b24-a2fc-4def-870e-65bd84b28a8c

Optogenetics: lighting the way to the future

Article in Maxwell, the quarterly magazine of the Electrotechnische Vereeniging, ETV, Issue 18.4, by Farnaz Nassiri Nia, MSc Student in the Section Bioelectronics on the basic principles of optogenetics and a state-of-the-art bioelectronics application for the treatment of epilepsy.

The brain is the mystery of the human body. Neurons, as primary units of the nervous system, are joined together into a complicated biological interconnected network. A conventional method to manipulate the neural performance within this network is to use drugs that alter the chemical balance of the brain. However, a crucial aspect of the nervous systems is the electrical signalling between the neurons. Bioelectronics has advanced the neural modulation techniques beyond the conventional methods by developing electrical brain stimulation tools. Electrical brain stimulation is truly beneficial to understand the mechanism underlying neural behaviour, and develop novel therapeutic methods. Optogenetics is another breakthrough method in neural stimulation techniques, which has opened up entirely new avenues of research opportunities in the fields of neuroscience and bioelectronics. In this article, the basic principles of optogenetics and a state-of-the-art bioelectronics application for the treatment of epilepsy are described.

Een betere toekomst begint vandaag

maslov_eeVoor verwelkoming van de aankomende 1e-jaars van de opleiding Electrical Engineering aan de TU Delft maakte ik tijdens het “Electro Ontvangst Weekend” (EOW) een presentatie. Deze presentatie vind je hier: http://elca.et.tudelft.nl/~wout/tmp/eow_2015_serdijn.pdf.

Neural stimulation: design of efficient and safe neural stimulators

Article by Marijn van Dongen on efficient and safe neurostimulation

Article by Marijn van Dongen, honorary aluminus of the Bioelectronics Group, in Maxwell 18.3, the quarterly magazine of the Electrotechnische Vereeniging, on the work he did for his PhD studies on power efficient and safe neurostimulation.

Read the entire article here: http://elca.et.tudelft.nl/~wout/tmp/neurostimulation_maxwell_18.3_vandongen.pdf

Lecture on Electroceuticals: getting better with electricity

Lecture on Electroceuticals: getting better with electricity

Lecture on Electroceuticals: getting better with electricity

On May 6, 2015, Collegerama of TU Delft made video recordings of the lecture I gave on Electroceuticals.

Electroceuticals are the electronic counterparts of pharmaceuticals and are miniature electronic devices that interact with the body in an electrical fashion.

In this talk I discuss: neurostimulation and the need to make neurostimulators smaller, more power efficient and more intelligent; optogenetic neuromodulation and the need to make this new neuromodulation modality operate in a closed-loop fashion; neurosensing devices to make neurostimulators intelligent and thereby adjust themselves to the therapeutical needs of the patient; autonomous wireless sensor nodes that can measure temperature or the electrocardiogram without the need for a battery; an outlook into the future of electroceuticals with the promise to treat a larger variety of neurological and brain disorders better.

Click here to start watching the video and slides:

https://collegerama.tudelft.nl/Mediasite/Play/cc7888beb88349c1a60c1414476b577a1d?catalog=528e5b24-a2fc-4def-870e-65bd84b28a8c

The injectable neurostimulator: an emerging therapeutic device

The injectable neurostimulator: an emerging therapeutic device

Xiaolong Li1Wouter A. Serdijn2Wei Zheng1Yubo Tian1Bing Zhang1
1 School of Electronics and Information, Jiangsu University of Science and Technology, Zhenjiang, China
2 Section of Bioelectronics, Delft University of Technology, Delft, the Netherlands

Available online 25 April 2015

Highlights

  • Injectable neurostimulators (InNSs) for clinical use are necessary to avoid the side effects of the dominant bulky implantable neurostimulator.
  • The concept, implementation challenges, and development trends of the InNS are illustrated in detail.
  • The new generation of InNSs can be powered from a microbattery, a radio-frequency energy harvester, or an inductive coupling link.
  • Obstacles include the implementation of injectable batteries, injectable antennas, and radio-frequency energy harvesters; the realization of InNSs also awaits breakthroughs in soft and bendable materials, reliability, and the mode of injection.

Injectable neurostimulators are currently applied in clinical trials to minimize the side effects such as discomfort, risk of infection, and post-surgery trauma, which can be pronounced with conventional, bulky implantable neurostimulators. Owing to its smaller size, wireless-updatable software, and wireless power supply, the injectable neurostimulator is presumably less invasive, ‘smarter’, and has a longer lifetime. We discuss the concept and development of the injectable neurostimulator, persistent implementation challenges, and obstacles to be overcome in its evolution. We survey the use of new materials, technologies, and design methods for injectable electrodes, batteries, antennas, and packaging to enhance reliability and other features. These advances in the field are accompanied by progress in electrophysiology, neuroscience, neurology, clinical trials, and treatments.

Keywords

  • biocompatible materials;
  • electrical nerve stimulation;
  • injectable neurostimulator;
  • injectable electronic devices;
  • therapeutic device