Cover of VN, Aug. 2, 2014
Article in Vrij Nederland (in Dutch), d. Aug. 2, by Marjolein van Trigt about Child Tracking. In there, Wouter Serdijn explains the possibilities, impossibilities and implications of an implantable RFID child tracker. Click here:
http://www.vn.nl/Archief/Samenleving/Artikel-Samenleving/Een-elektronisch-oogje-op-de-kinderen.htm#
Posted in Electronics, General
arXiv logo
We pre-published an important paper on a new neurostimulation paradigm on arXiv. The paper can be found here: http://arxiv.org/pdf/1406.7185v1.pdf.
Abstract: This paper investigates the efficacy of high frequency switched-mode neural stimulation. Instead of using a constant stimulation amplitude, the stimulus is switched on and off repeatedly with a high frequency (up to 100kHz) duty cycled signal. By means of tissue modeling that includes the dynamic properties of both the tissue material as well as the axon membrane, it is first shown that switched-mode stimulation depolarizes the cell membrane in a similar way as classical constant amplitude stimulation. These findings are subsequently verified using in vitro experiments in which the response of a Purkinje cell is measured due to a stimulation signal in the molecular layer of the cerebellum of a mouse. For this purpose a stimulator circuit is developed that is able to produce a monophasic high frequency switched-mode stimulation signal. The results confirm the modeling by showing that switched-mode stimulation is able to induce similar responses in the Purkinje cell as classical stimulation using a constant current source. This conclusion opens up possibilities for novel stimulation designs that can improve the performance of the stimulator circuitry. Care has to be taken to avoid losses in the system due to the higher operating frequency.
Authored by: M.N. van Dongen, F.E. Hoebeek, S.K.E. Koekkoek, C.I. De Zeeuw, W.A. Serdijn
Posted in General
Chipping a puppy
Yesterday I received a phone call from the Dutch NOS, the largest news organization in the Netherlands with the question whether the news about Martijn Aslander, “professional lifehacker”, who had an RFIC chip implanted in his hand, should be considered important from a news perspective. The answer is “No”. The implanted chip is hardly any more intelligent than those that cats, dogs and cattle are wearing already for many years and since the chip has no means of interaction with its owner, it is nothing more than an implanted passport or any other form of identification.
Aslander may perhaps be the first person in the Netherlands (if you do not count dogs, cats and cattle), but his heroism fades in the shadow of the true pioneer of cyborgs, Sir Kevin Warwick. See, e.g., http://www.kevinwarwick.com/. In the Netherlands and Belgium, true heroes are Eddy van der Velden and Dirk de Ridder (www.braininnovations.nl), who voluntarily had stimulation electrodes implanted to test alternative neurostimulation strategies and thereby contribute to finding better treatments for tinnitus and addiction. It is truly an honor and privilege to collaborate with them.
In the next few decades, implantable electronics could shift the focus of medical care from reactive, symptom-based diagnosis to early detection or prevention. Heralding that future is the Linq, a new cardiac monitor from medical device giant Medtronic. The company is already envisioning future versions of the implantable gadget, studded with sensors that will give doctors and patients reams of biometric information. The sensors could someday help athletes fine-tune their bodies for improved performance or let an elderly person live independently while his or her vitals are monitored remotely. Medtronic believes that it will eventually be seen as negligent not to have these sensors installed—whether you’re elderly and infirm, or young, fit, and healthy.
Read more on:
Posted in General
Since its online publication on May 26, 2009, there has been a total of 3894 chapter downloads for the book “Ultra Low-Power Biomedical Signal Processing”, authored by Sandro Haddad and Wouter Serdijn.
More information can be found on the book’s web page: http://www.springer.com/engineering/signals/book/978-1-4020-9072-1.
Posted in General
Published on YouTube, Jan 7, 2014
GSK’s Bioelectronics R&D unit is pursuing a relatively new scientific field that could one day result in a new class of medicines that would not be pills or injections but miniaturised, implantable devices. GSK believes that these devices could be programmed to read and correct the electrical signals that pass along the nerves of the body, including irregular or altered impulses that can occur in association with a broad range of diseases. The hope is that through these devices, disorders as diverse as inflammatory bowel disease, arthritis, asthma, hypertension and diabetes could be treated. See: https://www.youtube.com/watch?v=NhXtSy-Ccvg
Posted in General
[youtube]http://www.youtube.com/watch?v=3TS411KXyWs[/youtube]
Published on Jul 10, 2013
Una pequeña descripción de su investigación, en circuitos de bajo consumo y miniaturización de los mismos. Su descripción aqui http://cass-school.uniandes.edu.co/lecturers.html.
Posted in Education, Electronics, General
Injectable electronics still need to become smaller
Frequent readers of this weblog may still remember a previous post, entitled “And the paralyzed will walk again“. This phrase comes from a Discovery Channel movie/documentary, called “2057: the body”, in which it is predicted that by the year 2057 you will be able to survive a three story fall and even be able to walk again as there will be tiny microstimulators attached to your muscles, which can be injected.
Injectable electronics, how fascinating would that be! No more lengthy surgeries, during which only a single, bulky device is implanted, but rather a procedure that takes less than a couple of minutes, during which multiple micro-stimulators are inserted via a seringe. Once done, these stimulators will form a wireless network and will provide the motory neural pathway with well-timed electric stimuli necessary to evoke the correct contraction of the multiple muscles involved in a delicate movement or even seemingly simple posture control.
But how feasible is this idea of injectable electronics? If you search for the term injectable electronics, you will most likely find a lot of references to the work of John Rogers, professor at the University of Illinois in the US, who built “an electronic LED device so tiny it can be injected into delicate tissue, such as in the brain, without harming it“.
Other links that can be found refer to work done on silk implants or even magnesium implants that are either stretchable or can easily dissolve into the body once the good work has been done.
I personally believe that we only can create injectable electronic devices if they have at least some intelligence in them. For this, the good old silicon would be an excellent candidate. Silicon is a nice and friendly biocompatible material, can be made bendable (by thinning the substrate) or stretchable (by removing the substrate altogether at some points). And what’s more, silicon can accommodate stimulation circuitry, sensors, signal processing, communication electronics, antennas, battery foils, all the good stuff needed to make a good injectable.
Of course, in order not to damage the tissue that the electronic device is injected in, it needs to be small, i.e., thin and narrow. It is however allowed to make it long, e.g., a couple of millimeters up to one or two centimeters. These unconventional dimensions raise very exciting technological challenges, such as:
There obviously is still a lot to do. Exciting stimes ahead, if you ask me.
Wouter