Category Archives: neurostimulation

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.

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.

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

Nieuwe stimulatie-methode effectiever tegen hersen- en zenuwaandoeningen

Persbericht van de TU Delft, uitgegeven vandaag (23 april 2015):
Nieuwe stimulatie-methode effectiever tegen hersen- en zenuwaandoeningen 

HF_stimulatorHersenstimulatie wordt tegenwoordig succesvol toegepast ter bestrijding van ziektes als Parkinson, chronische depressie, pijn en tinnitus. Door neurostimulatoren energiezuiniger en kleiner te maken, kunnen ze doelgerichter en voor een groter scala aan hersen- en zenuwaandoeningen worden ingezet. Marijn van Dongen maakte een prototype van een chip waarmee deze vorm van neurostimulatie kan worden toegepast. Hij promoveert op vrijdag 24 april op dit onderwerp aan de TU Delft. 

Parkinson

Hersenstimulatie wordt tegenwoordig succesvol toegepast ter bestrijding van ziektes zoals Parkinson, chronische depressie, pijn en tinnitus en er zijn aanwijzingen dat hersenstimulatie ook succesvol kan zijn in de behandelingen van nog veel meer hersenaandoeningen, zoals epilepsie, verslavingen, migraine en dementie. Veel bestaande neuro-stimulatoren hebben echter een beperkte energie-efficiëntie, waardoor een grote batterij nodig is. Een grote batterij maakt de hele neurostimulator groot waardoor deze niet op de plaats geïmplanteerd kan worden waar de stimulatie ook daadwerkelijk nodig is. Vaak verbinden onderhuidse draden de neurostimulator in de borst met de elektroden in de hersenen.

HF

Daarom is aan de TU Delft een nieuwe manier van neurostimulatie onderzocht: hoog-frequente (HF) neurostimulatie. De doelmatigheid van deze HF-stimulatie in aangetoond via simulaties en met in-vitro-metingen (in samenwerking met de afdeling Neurowetenschappen van het Erasmus Medisch Centrum). HF-stimulatie heeft hetzelfde effect op weefsel als klassieke stimulatie, alleen kan HF-stimulatie energiezuiniger zijn. De batterij kan daarmee kleiner worden en er zijn minder ruimte-verslindende componenten nodig.

Pulsjes

‘In mijn promotieonderzoek hebben we gefocust op nieuwe stimulatie-patronen die efficiënt opgewekt kunnen worden’, zegt Marijn van Dongen. ‘In plaats van met een constante stroom, stimuleren we de hersenen met een serie hoogfrequente stroom-pulsjes. Dit soort pulsjes kunnen op een energie-efficiënte manier worden opgewekt dankzij het principe van een geschakelde voeding. We hebben een energiezuinige neurostimulator-chip ontworpen die tot wel 200% energiezuiniger kan zijn dan zijn klassieke tegenhangers. Hierdoor kunnen toekomstige neurostimulatoren kleiner worden gemaakt en daarmee voor een groter scala aan hersen- en zenuwaandoeningen worden ingezet. Bovendien kunnen deze pulsjes verschillende doelen tegelijkertijd activeren en daarmee de doelmatigheid van de neurostimulatie verhogen.’

Prototype

Er is een prototype chip ontwikkeld waarmee deze vorm van neurostimulatie kan worden toegepast. In samenwerking met neurowetenschappers van het Erasmus Universitair Medisch Centrum, de University of Texas at Dallas (VS) en de University of Otago (Nieuw-Zeeland) is de methode succesvol geverifieerd.

Colloquium

Voorafgaand aan de promotie van Marijn van Dongen is er een colloquium over neurostimulatie door prof. Dirk De Ridder: the future of brain, spine and nerve stimulation. Prof.dr. Dirk De Ridder bekleedt de Neurological Foundation Chair in Neurosurgery aan de Dunedin School of Medicine, University of Otago, Nieuw-Zeeland (vrijdag 24 april, 10.00-11.15 uur; Snijderszaal: EWI-LB01.010, TU Delft).

Meer informatie
Voor meer informatie neemt u contact op met Marijn van Dongen, afdeling Micro-Elektronica van de faculteit Elektrotechniek, Wiskunde en Informatica, M.N.vanDongen@tudelft.nl, 06 – 435 70479 of met Claire Hallewas, wetenschapsvoorlichter TU Delft, C.R.Hallewas@tudelft.nl, 015 – 27 84259. Het volledige proefschrift vindt u op de TU Delft repository.”

Electroceuticals: the Shocking Future of Brain Zapping

Electroceuticals are the electronic counterparts of pharmaceuticals

“It’s all in your head—those icky feelings, all that fog—and chemicals just aren’t that great at cutting through. That’s why scientists are experimenting with changing the brain game by tweaking its circuitry, rather than the chemical processes.

It might be a bit unnerving to us seasoned pill-poppers, but some believe that electrical currents could be the new wave in everything cerebral, from treating depression and addiction to enhancements that would enable those seeking that mental edge to learn new skills faster or remember more.”

Read more at: http://motherboard.vice.com/read/electroceuticals-the-shocking-future-of-brain-zapping.

We cured several mice from epilepsy!

The cerebellum might be able to stop epileptic seizures

A single short-lasting (30-300 ms) optogenetic stimulation of the cerebellum (the small brains) abruptly stopped generalized spike-wave discharges (GSWDs) as occur, e.g., in absence epileptic seizures, even when applied unilaterally. Using a closed-loop system absence seizures were detected and stopped within 500 ms.

If you want to read more about the neuroscientific aspects, click here. If you want to read more about the epilepsy detector we developed, click here.

We are now working on our next mission: to reliably detect other forms of epileptic seizures and to study cerebellar nuclei further and their potential therapeutic benefit for controlling other types of generalized epilepsies.

Exciting times ahead, if you ask me, and not only for mice.

Cerebellar output controls generalized spike-and-wave discharge occurrence

Cerebellar output controls generalized spike-and-wave discharge occurrence.

Abstract

OBJECTIVE:

Disrupting thalamocortical activity patterns has proven to be a promising approach to stop generalized spike-and-wave discharges (GSWDs) characteristic of absence seizures. Here, we investigated to what extent modulation of neuronal firing in cerebellar nuclei (CN), which are anatomically in an advantageous position to disrupt cortical oscillations through their innervation of a wide variety of thalamic nuclei, is effective in controlling absence seizures.

METHODS:

Two unrelated mouse models of generalized absence seizures were used; the natural mutant tottering, which is characterized by a missense mutation in Cacna1a, and inbred C3H/HeOuJ. While simultaneously recording single CN neuron activity and electrocorticogram (ECoG) in awake animals, we investigated to what extent pharmacologically increased or decreased CN neuron activity could modulate GSWD occurrence and short-lasting on-demand CN stimulation could disrupt epileptic seizures.

RESULTS:

We found that a subset of CN neurons shows phase-locked oscillatory firing during GSWDs and that manipulating this activity modulates GSWD occurrence. Inhibiting CN neuron action potential firing by local application of the GABAA -agonist muscimol increased GSWD occurrence up to 37-fold, whereas increasing the frequency and regularity of CN neuron firing with the use of gabazine decimated its occurrence. A single short-lasting (30-300 ms) optogenetic stimulation of CN neuron activity abruptly stopped GSWDs, even when applied unilaterally. Using a closed-loop system GSWDs were detected and stopped within 500 ms.

INTERPRETATION:

CN neurons are potent modulators of pathological oscillations in thalamocortical network activity during absence seizures and their potential therapeutic benefit for controlling other types of generalized epilepsies should be evaluated.

This article is protected by copyright. All rights reserved.

© 2015 American Neurological Association.

PMID: 25762286
[PubMed – as supplied by publisher]

Building a Bionic Nervous System

Electroceuticals Inside!

“It’s an electrifying time to be in neuroscience. Using implanted devices that send pulses of electricity through the nervous system, physicians are learning how to influence the neural systems that control people’s bodies and minds. These devices give neurologists new ways to treat patients with a wide range of disorders, including epilepsy, chronic pain, depression, and Parkinson’s disease. So far, these stimulators have been oneway devices that deliver a steady sequence of pulses to the nervous system but can’t react to changes in the patient’s body. Now, at last, medical device companies are coming out with dynamic neural stimulators that have a bit of “brain” themselves. These smart systems can detect changes in a physiological signal and then respond by delivering a therapy or adjusting the patient’s treatment in real time.”

Abstract of a paper by Tim Denison, Milton Morris and Felice Sun in IEEE Spectrum, Febr. 2015, DOI: 10.1109/MSPEC.2015.7024509.