Category Archives: General

The injectable neurostimulator: an emerging therapeutic device

Posted on 28/04/2015 by | Leave a comment

The injectable neurostimulator: an emerging therapeutic device

Xiaolong Li1, , Wouter A. Serdijn2, Wei Zheng1, Yubo Tian1, Bing 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

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Posted in Electronics, Energy Harvesting, General, Neurostimulation and Neuromodulation

REMINDER: ISCAS 2015 Advance Registration Deadline (April 30th) Approaching Quickly

Posted on 26/04/2015 by | Leave a comment

REMINDER: ISCAS 2015 Advance Registration Deadline Notice & Call for Participation

2015 IEEE International Symposium on Circuits and Systems (ISCAS) Lisbon, Portugal
24-27 May 2015

http://www.iscas2015.org/

ISCAS 2015 HIGHLIGHTS:
– Keynote by Behzad Razavi: “The Future of Radios”
– Keynote by Ronald Dekker: “From Chips for the Living to Living Chips”
– Keynote by Luís Gomes: “Changing the Economics of Space: Small Spacecraft and COTS Electronics”
– John Choma Commemorative Session on Reconfigurable and Adaptive Analog, Mixed-Signal, and Radio-Frequency Integrated Circuits, with contributions from Yannis Tsividis, Franco Maloberti, Edgar Sanchez-Sinencio, Hossein Hashemi and Randy Geiger.
– John Choma Commemorative Session on Ultra-Low-Power Integrated Circuits and Systems for Biomedical Implants, with contribution from Mohamad Sawan, Ralph Etienne-Cummings, Wouter Serdijn, Herming Chiueh and Roman Genov.
– Conference Leadership Workshop

HOTEL RESERVATIONS:
Rooms at different hotels in Lisbon have been booked for the convenience of the participants and are to be assigned on a first-come first-served basis. Please visit the conference web site for additional information.

http://www.iscas2015.org/travel/hotels/

Advance Registration Deadline: April 30th

GENERAL CHAIRS’ MESSAGE

Queridos amigos,

On behalf of the Organizing Committee, we are pleased and honored to invite and welcome you to Lisbon and to the 2015 IEEE International Symposium on Circuits and Systems (ISCAS 2015). The conference theme, “Enabling Technologies for Societal Challenges”, in line with the 2020 European Research and Innovation Roadmap and the Grand Engineering Challenges, suits extremely well our community’s inter-disciplinary and cross-disciplinary research activities.

ISCAS is the main event of the IEEE Circuits and Systems Society and the world’s premier networking forum for leading researchers in the highly active fields of theory, design and implementation of circuits and systems. The Technical Program Co-Chairs for this year edition, João Goes and Philipp Häfliger, have assembled an outstanding program with three full days of lectures and poster sessions covering 16 tracks. The most outstanding contributions to these tracks will be considered for the Best Student Paper Award contest and the Best Live Demo Award contest. The winners of both awards will be selected and announced during the conference.

ISCAS 2015 also offers high-quality and leading–edge tutorials and special sessions from worldwide experts, either in specific and in multidisciplinary areas, suited for those looking for a birds-eye view on a new research area or to improve their areas of expertise.

A set of world-class keynote speeches will be presented.

Apart from the scientific contributions, ISCAS 2015 will offer a forum that promotes the interaction between industry, start-ups, PhD students, academia and research funding agencies. This interaction will have place through industry presence, debates and talks.

ISCAS 2015 maintains the Women in CAS (WiCAS) activity as well as the Young Professionals Program (YPP) activity and will also host a “Conference Leadership Workshop”, a Special “John Choma Commemorative” Session with 10 distinguished invited speakers and other events, further enriching the technical program.

As for the social program we will try to match the quality of the technical program and of the tutorial offerings. On Tuesday, the Award Ceremony will be held in an opera house auditorium followed by the Gala Dinner in the Convento do Beato, a magnificent former monastery that dates back to the 15th century.

ISCAS 2015 will assist in sharing and disseminating your specific and inter- and cross-disciplinary technical achievements and will bring together diverse participants, histories and cultures. We look forward to your active participation in this magnificent event!

Um abraço,
Jorge Fernandes and Wouter Serdijn

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Posted in Education, General

Nieuwe stimulatie-methode effectiever tegen hersen- en zenuwaandoeningen

Posted on 23/04/2015 by | Leave a comment

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.”

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Posted in Electronics, General, Neurostimulation and Neuromodulation, Understanding the Brain

Electroceuticals: the Shocking Future of Brain Zapping

Posted on 19/04/2015 by | Leave a comment

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.

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Posted in Brain-Machine Interfaces, Electronics, General, Neurostimulation and Neuromodulation, Understanding the Brain

Future hardware improvements in implantable hearing devices

Posted on 30/03/2015 by | Leave a comment
Damaged situation of the middle and inner ear; hair cells are damaged or non-existent, nerve cells are not fully developed or do not reach the cochlea [3].

Damaged situation of the middle and inner ear; hair cells are damaged or non-existent, nerve cells are not fully developed or do not reach the cochlea [3].

In this essay, by Ide Swager, MSc student in bioelectronics, an overview of current and future developments in implantable hearing devices is presented. It has been written as part of the course Introduction to Microelectronics for the M.Sc. track Microelectronics of the faculty Electrical Engineering, Mathematics and Computer Science of Delft University of Technology. A brief version of the auditory anatomy is included to clarify the causes of deafness. After elaborating on the current devices available and the basic working principle, future trends are explored. These include Neural Response Telemetry (NRT), combined Acoustic and Electric Stimulation (EAS) and binaural devices.

Read the full essay here: http://elca.et.tudelft.nl/~wout/tmp/iswager_essay.pdf

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Posted in Education, Electronics, General, Understanding the Brain

Cochlear implant development going at a rapid pace (in Dutch)

Posted on 27/03/2015 by | Leave a comment

Uit “De Audiciens”, februari 2015: “CI’s (cochleaire implantaten, Red.) volop in ontwikkeling.

Het is een traditie, de refereeravond van KNO/Centrum voor Audiologie en Hoorimplantaten (CAHIL) in het LUMC op de tweede donderdag van het jaar.

Ook op 8 januari 2015 zit de collegezaal weer vol. Het is dan ook een bijeenkomst waar een aantal disciplines uit de hoorbranche samenkomen. KNO-artsen, audiologen, akoepedisten, audiciens, fabrikanten en anderen luisteren naar voordrachten die inzicht geven in nieuwe ontwikkelingen op audiologisch gebied.

De avond wordt geopend door prof. dr. ir. J.H.M. Frijns, hoofd CAHIL. (…) In het kader van de Medical Delta (een samenwerkingsverband tussen het Erasmus MC in Rotterdam, de TU Delft en het LUMC in Leiden voor de ontwikkeling van medische technologie) is er een presentatie van Johan de Vos die als arts-onderzoeker KNO onderzoek verricht naar nieuwe technologie voor cochleaire implantaten. Onder begeleiding van Wouter Serdijn en Paddy French hebben drie promovendi van de TU een meetversterker (Cees Jeroen Bes), een elektrode ontwerp (Nishant Lawant) en een stimulatorchip (Wannaya Ngamkham) ontwikkeld. Deze technologie wordt onder leiding van Johan Frijns en Jeroen Briaire in het LUMC geimplanteerd en getest door Johan de Vos. Tevens ontwikkelt het LUMC nieuwe meetmethodes voor het terugmeten van de respons van de gehoorzenuw (Dick Biesheuvel).”

Lees meer hier.

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Posted in General

We cured several mice from epilepsy!

Posted on 18/03/2015 by | Leave a comment

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.

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Posted in Brain-Machine Interfaces, Electronics, General, Neurostimulation and Neuromodulation, Understanding the Brain

Cerebellar output controls generalized spike-and-wave discharge occurrence

Posted on 15/03/2015 by | Leave a comment

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

Kros L, Eelkman Rooda OH, Spanke JK, Alva P, van Dongen MN, Karapatis A, Tolner EA, Strydis C, Davey N, Winkelman BH, Negrello M, Serdijn WA, Steuber V, van den Maagdenberg AM, De Zeeuw CI, Hoebeek FE.

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]

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Posted in General, Neurostimulation and Neuromodulation, Understanding the Brain

How to optimize the antenna-electronics interface

Posted on 13/03/2015 by | Leave a comment
Autonomous Wireless ECG Sensor Node by Andre Mansano and Yongjia Li

Autonomous Wireless ECG Sensor Node by Andre Mansano and Yongjia Li

During the design process of a wireless system, the antenna and electronic circuit designers sometimes are operating independently from each other and considered to belong to separate disciplines. Both designers agree upon a common characteristic impedance (Z0) of the antenna electronics interface and subsequently optimize their part of the system. The electronic circuit often requires an impedance transformation network while the antenna usually is directly matched to the characteristic impedance of a transmission line to avoid propagation effects in the interface. Traditionally, this characteristic impedance is commonly assumed to be 50 Ω, without any further discussion. Although this standardization may be convenient from a measurement point of view, it is a rather uncomfortable assumption to make as it clearly cannot be the optimum impedance for all design challenges when for example considering noise performance, efficiency or antenna size.

By co-designing the antenna-electronics interface, both disciplines share a common optimization target and can agree on an alternative interface impedance to optimize the overall system performance for a specific application. The choice of interface impedance plays a crucial role in the optimization of antenna systems in the receiving mode, which is the topic addressed in this brief.

Read more in this paper by Mark Stoopman and Yao Liu here.

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Posted in General

Rewiring the brain – creating artificial vision

Posted on 11/03/2015 by | Leave a comment
creating artificial vision

creating artificial vision

For our course “Introduction in Microelectronics” MSc student Lucas van Dijk wrote an inspiring essay about how you can either restore vision for the blind or create enhanced vision for people that see normally.

The essay can be found here.

The abstract reads: “The current state of visual prostheses progresses rapidly. In this essay three approaches to a visual prosthesis are discussed: an epiretinal implant, a visual prosthesis which stimulates the optic nerve, and a visual prosthesis which stimulates the lateral geniculate nucleus. While the epiretinal implants are currently the most advanced visual prostheses available, I think
a visual prosthesis stimulating the lateral geniculate nucleus has the greatest potential, especially when you also keep applications for people with healthy vision.”

Enjoy!

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Posted in General