electrodes

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Crystals and copper in Paul’s Lab

Dendritic Gold Crystals:

This amazing crystal of pure gold was grown through vapor deposition and is only 10mm high.

I had to use my microscope to make this detailed photo, using 75 individual photos and putting them together with focus stacking.

It really is this bright and shiny!

Silver Crystals:

These silver crystals were electrochemically grown from a solution of silver nitrate, using silver electrodes. 

The field of view is 18 mm and is composed of 92 individual photos, combined using focus stacking.

Copper Dendrites:

This dendritic structure of pure copper was grown during the copper plating or electro plating of various objects.

The field of view is about 3 cm high.

Magnesium Crystal Cluster Close-up:

This is a close-up of a synthetic magnesium crystal cluster. It was done by distilling magnesium and the group is about 3 cm wide. It is part of my personal collection of elements.

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These are beautiful! I love looking at these structures, the colors are so captivating and the structures and quite marvelous.

The copper structure looks like a volcanic eruption of some sort, and I just thought of what it would be like to see these crystal formations on a larger scale. Nonetheless, they are still magnificent in their uniqueness and originality.

World premiere of muscle and nerve controlled arm prosthesis

For the first time an operation has been conducted, at Sahlgrenska University Hospital, where electrodes have been permanently implanted in nerves and muscles of an amputee to directly control an arm prosthesis. The result allows natural control of an advanced robotic prosthesis, similarly to the motions of a natural limb.

A surgical team led by Dr Rickard Brånemark, Sahlgrenska University Hospital, has carried out the first operation of its kind, where neuromuscular electrodes have been permanently implanted in an amputee. The operation was possible thanks to new advanced technology developed by Max Ortiz Catalan, supervised by Rickard Brånemark at Sahlgrenska University Hospital and Bo Håkansson at Chalmers University of Technology.

“The new technology is a major breakthrough that has many advantages over current technology, which provides very limited functionality to patients with missing limbs,” says Rickard Brånemark.

Big challenges
There have been two major issues on the advancement of robotic prostheses: 1) how to firmly attach an artificial limb to the human body; 2) how to intuitively and efficiently control the prosthesis in order to be truly useful and regain lost functionality.

“This technology solves both these problems by combining a bone anchored prosthesis with implanted electrodes,” said Rickard Brånemark, who along with his team has developed a pioneering implant system called Opra, Osseointegrated Prostheses for the Rehabilitation of Amputees.

A titanium screw, so-called osseointegrated implant, is used to anchor the prosthesis directly to the stump, which provides many advantages over a traditionally used socket prosthesis.

“It allows complete degree of motion for the patient, fewer skin related problems and a more natural feeling that the prosthesis is part of the body. Overall, it brings better quality of life to people who are amputees,” says Rickard Brånemark.

How it works
Presently, robotic prostheses rely on electrodes over the skin to pick up the muscles electrical activity to drive few actions by the prosthesis. The problem with this approach is that normally only two functions are regained out of the tens of different movements an able-body is capable of. By using implanted electrodes, more signals can be retrieved, and therefore control of more movements is possible. Furthermore, it is also possible to provide the patient with natural perception, or “feeling”, through neural stimulation.

“We believe that implanted electrodes, together with a long-term stable human-machine interface provided by the osseointegrated implant, is a breakthrough that will pave the way for a new era in limb replacement,” says Rickard Brånemark.

The patient
The first patient has recently been treated with this technology, and the first tests gave excellent results. The patient, a previous user of a robotic hand, reported major difficulties in operating that device in cold and hot environments and interference from shoulder muscles. These issues have now disappeared, thanks to the new system, and the patient has now reported that almost no effort is required to generate control signals. Moreover, tests have shown that more movements may be performed in a coordinated way, and that several movements can be performed simultaneously.

“The next step will be to test electrical stimulation of nerves to see if the patient can sense environmental stimuli, that is, get an artificial sensation. The ultimate goal is to make a more natural way to replace a lost limb, to improve the quality of life for people with amputations,” says Rickard Brånemark.

Stretchy gold electronics could one day live inside your brain

What looks like a shiny piece of gold foil is actually a new stretchy conductive material that could one day be fashioned into electrode implants for the brain or pacemakers for the heart. Crafted from gold nanoparticles and an elastic polymer, the material retains its conductivity even when stretched to four times its original length.

“It looks like elastic gold,” said Nicholas Kotov, a chemical engineer at the University of Michigan. “But we can stretch it just like a rubber band.” When it stretches, it retains all the properties of a metal, including the ability to transport electrons.

Normally, stretching a circuit disrupts the interatomic connections that keep electrons flowing from one end to the other. Most existing stretchable electronics overcome this difficulty by using accordion- or spring-like folding wires that can expand and contract. But in the new material, no folds or convolutions are needed.

Its secret? Self-organising gold nanoparticles that have been embedded into an elastic polymer, polyurethane.

When the shiny material is stretched, the nanoparticles self-organise into conductive chains, scurrying to fill the gaps in the elongating material. It’s the first material that relies on nanospheres to achieve intrinsic stretchable conductivity, Kotov and his colleagues reported on 17 July in Nature.

Looking at the substance under electron microscopes revealed that the spheres snapped into chains under pressure, producing structures electrons could flow through. “And when you release the stress, they pretty much come back to their original position,” Kotov said.

The process is repeatable. And although conductance at maximal stretch is decreased to less than 10 percent of the original, it’s still enough to provide power to some devices, the team reports.

“The results suggest some very interesting, unexpected effects of nanoparticle-elastomer composites,” said John Rogers, a materials scientist at the University of Illinois. Rogers and his lab have developed an array of super-cool flexible, silicon-based circuits that use serpentine wires and buckled folds for stretching and contraction. “These types of conducting materials could provide new options in engineering design,” he said.

Someday, the gold-and-polyurethane material might live inside your head - in the form of implantable electrodes for treating movement disorders or other conditions. Or maybe, it will find its place on your heart, as part of a device that regulates cardiac activity. Scientists have been searching for ways to make pliant, biocompatible electronics that can bend and stretch and mold to the human body’s many curved surfaces, whether in the form of temporary tattoos or circuits that hug the ridges on the brain’s surface.

Kotov and his team are currently testing whether other nanoparticles can be used to create stretchy conductors. They’re also evaluating how prototype implants made from the nanogold and elastic polymers perform in rat brains. Then, the key will be to move from a stretchy conductor to a functioning, stretchy electronic system.

Violinist plays during brain surgery.

Musician Roger Frisch underwent deep brain stimulation to fix tremors in his hands and played the violin throughout the process. Deep brain stimulation is a technique used to aid people with Parkinson’s disease, dystonia (neurological movement disorder) and essential tremors, as well as people suffering from OCD, major depression or chronic pain.

During the procedure, surgeons place electrodes inside the deepest parts of the brain and use electric pulses to modify neurological responses. Surgeons implanted electrodes into Roger’s thalamus while he was still awake in an attempt to rectify his tremors.

There are no pain receptors in the brain so patients are always conscious during brain surgery so that the doctors can monitor their condition. In Roger’s case, the surgeons were concerned that the tremors were so small that they risked placing the electrodes in the wrong position and failing to fix the shaking. 

(To read more).

So today in Chemistry our lecturer asks “So what exactly is an electrode?”

I reply in front of everyone “It’s a Pokemon, John.”

I now realise why the rest of the class thinks I’m a twat. I also realise that I should start taking this shizzle seriously. I’ll start Thursday.

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Luigi Aloisio Galvani; Benedectine member of the Academy of Sciences’ Bioelectrical Experiments, Bologna, Italy, c. 1771.

[Bioelectromagnetics]

The Judge Rotenberg Center, a residential school in northern Massachusetts, prides itself on teaching students with disabilities who have the most challenging behavioral issues. The school takes kids with severe intellectual disabilities – autism, post-traumatic stress disorder, obsessive compulsive disorder, and a range of psychiatric disabilities – and then its employees attach electrodes to their arms, legs, and stomach, and shock them into submission.

Really.

One former resident, Andre McCollins, was shocked for… not taking off his coat quickly enough.

When he screamed in pain and tried to hide under a table, they shocked him for that. When he cried out for help, they shocked him for that. When he tensed up in anticipation of the next shock, they shocked him for that.

Over the next several hours, he was tied down to a restraint board and shocked 31 times. When his mother came to visit the next day, he was catatonic. He could not speak or even turn his head. He had open sores where the electrodes had been attached to his body. She took him to a hospital, where he remained for the next five weeks.

Rats Show Regret After Wrong Choices, Scientists Say

Researchers studied brain areas involved in decision making, evaluating outcomes.

Could’ve, should’ve, would’ve. Everyone has made the wrong choice at some point in life and suffered regret because of it. Now a new study shows we’re not alone in our reaction to incorrect decisions. Rats too can feel regret.

Regret is thinking about what you should have done, says David Redish, a neuroscientist at the University of Minnesota in Minneapolis. It differs from disappointment, which you feel when you don’t get what you expected. And it affects how you make decisions in the future. 

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Fighting disease deep inside the brain

Some 90,000 patients per year are treated for Parkinson’s disease, a number that is expected to rise by 25 percent annually. Deep Brain Stimulation (DBS), which consists of electrically stimulating the central or peripheral nervous system, is currently standard practice for treating Parkinson’s, but it can involve long, expensive surgeries with dramatic side effects. Miniature, ultra-flexible electrodes developed in Switzerland, however, could be the answer to more successful treatment for this and a host of other health issues.

Today, Professor Philippe Renaud of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland reports on soft arrays of miniature electrodes developed in his Microsystems Laboratory that open new possibilities for more accurate and local DBS. At the 2013 Annual Meeting of the American Association for the Advancement of Science (AAAS) in Boston, in a symposium called “Engineering the Nervous System: Solutions to Restore Sight, Hearing, and Mobility,” he announces the start of clinical trials and early, yet promising results in patients, and describes new developments in ultra-flexible electronics that can conform to the contours of the brainstem—in the brain itself—for treating other disorders.

At AAAS, Renaud outlines the technology behind these novel electronic interfaces with the nervous system, the associated challenges, and their immense potential to enhance DBS and treat disease, even how ultra flexible electronics could lead to the auditory implants of the future and the restoration of hearing. “Although Deep Brain Stimulation has been used for the past two decades, we see little progress in its clinical outcomes,” Renaud says. “Microelectrodes have the potential to open new therapeutic routes, with more efficiency and fewer side effects through a much better and finer control of electrical activation zones.” The preliminary clinical trials related to this research are being done in conjunction with EPFL spin-off company Aleva Neurotherapeutics, the first company in the world to introduce microelectrodes in Deep Brain Stimulation leading to more precise directional stimulation.

First signals from brain nerve cells with ultrathin nanowires

Electrodes operated into the brain are today used in research and to treat diseases such as Parkinson’s. However, their use has been limited by their size. At Lund University in Sweden, researchers have, for the first time, succeeded in implanting an ultrathin nanowire-based electrode and capturing signals from the nerve cells in the brain of a laboratory animal.

The researchers work at Lund University’s Neuronano Research Centre in an interdisciplinary collaboration between experts in subjects including neurophysiology, biomaterials, electrical measurements and nanotechnology. Their electrode is composed of a group of nanowires, each of which measures only 200 nanometres (billionths of a metre) in diameter.

Such thin electrodes have previously only been used in experiments with cell cultures.

“Carrying out experiments on a living animal is much more difficult. We are pleased that we have succeeded in developing a functioning nano-electrode, getting it into place and capturing signals from nerve cells”, says Professor Jens Schouenborg, who is head of the Neuronano Research Centre.

He sees this as a real breakthrough, but also as only a step on the way. The research group has already worked for several years to develop electrodes that are thin and flexible enough not to disturb the brain tissue, and with material that does not irritate the cells nearby. They now have the first evidence that it is possible to obtain useful nerve signals from nanometre-sized electrodes.

The research will now take a number of directions. The researchers want to try and reduce the size of the base to which the nanowires are attached, improve the connection between the electrode and the electronics that receive the signals from the nerve cells, and experiment with the surface structure of the electrodes to see what produces the best signals without damaging the brain cells.

“In the future, we hope to be able to make electrodes with nanostructured surfaces that are adapted to the various parts of the nerve cells – parts that are no bigger than a few billionths of a metre. Then we could tailor-make each electrode based on where it is going to be placed and what signals it is to capture or emit”, says Jens Schouenborg.

When an electrode is inserted into the brain of a patient or a laboratory animal, it is generally anchored to the skull. This means that it doesn’t move smoothly with the brain, which floats inside the skull, but rather rubs against the surrounding tissue, which in the long term causes the signals to deteriorate. The Lund group’s electrodes will instead be anchored by their surface structure.

“With the right pattern on the surface, they will stay in place yet still move with the body – and the brain – thereby opening up for long-term monitoring of neurones”, explains Jens Schouenborg.

He praises the collaboration between medics, physicists and others at the Neuronano Research Centre, and mentions physicist Dmitry B. Suyatin in particular. He is the principal author of the article which the researchers have now published in the international journal PLOS ONE.

The overall goal of the Neuronano Research Centre is to develop electrodes that can be inserted into the brain to study learning, pain and other mechanisms, and, in the long term, to treat conditions such as chronic pain, depression and Parkinson’s disease.

Prosthetic electrodes will return amputees’ sense of touch

For all the functionality and freedom that modern prosthetics provide, they still cannot give their users a sense of what they’re touching. That may soon change thanks to an innovative electrode capable of connecting a prosthetic arm’s robotic sense of touch to the human nervous system that it’s attached to. 
It reportedly allows its users to feel heat, cold and pressure by stimulating the ulnar and median nerves of the upper arm. 

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Novel wireless brain sensor

A team of neuroengineers based at Brown University has developed a fully implantable and rechargeable wireless brain sensor capable of relaying real-time broadband signals from up to 100 neurons in freely moving subjects. Several copies of the novel low-power device, described in the Journal of Neural Engineering, have been performing well in animal models for more than year, a first in the brain-computer interface field. Brain-computer interfaces could help people with severe paralysis control devices with their thoughts.

Arto Nurmikko, professor of engineering at Brown University who oversaw the device’s invention, is presenting it this week at the 2013 International Workshop on Clinical Brain-Machine Interface Systems in Houston.

“This has features that are somewhat akin to a cell phone, except the conversation that is being sent out is the brain talking wirelessly,” Nurmikko said.

Neuroscientists can use such a device to observe, record, and analyze the signals emitted by scores of neurons in particular parts of the animal model’s brain.

Meanwhile, wired systems using similar implantable sensing electrodes are being investigated in brain-computer interface research to assess the feasibility of people with severe paralysis moving assistive devices like robotic arms or computer cursors by thinking about moving their arms and hands.

This wireless system addresses a major need for the next step in providing a practical brain-computer interface,” said neuroscientist John Donoghue, the Wriston Professor of Neuroscience at Brown University and director of the Brown Institute for Brain Science.

Tightly packed technology

In the device, a pill-sized chip of electrodes implanted on the cortex sends signals through uniquely designed electrical connections into the device’s laser-welded, hermetically sealed titanium “can.” The can measures 2.2 inches (56 mm) long, 1.65 inches (42 mm) wide, and 0.35 inches (9 mm) thick. That small volume houses an entire signal processing system: a lithium ion battery, ultralow-power integrated circuits designed at Brown for signal processing and conversion, wireless radio and infrared transmitters, and a copper coil for recharging — a “brain radio.” All the wireless and charging signals pass through an electromagnetically transparent sapphire window.

In all, the device looks like a miniature sardine can with a porthole.

But what the team has packed inside makes it a major advance among brain-machine interfaces, said lead author David Borton, a former Brown graduate student and postdoctoral research associate who is now at Ecole Polytechnique Federale Lausanne in Switzerland.

“What makes the achievement discussed in this paper unique is how it integrated many individual innovations into a complete system with potential for neuroscientific gain greater than the sum of its parts,” Borton said. “Most importantly, we show the first fully implanted microsystem operated wirelessly for more than 12 months in large animal models — a milestone for potential [human] clinical translation.”

The device transmits data at 24 Mbps via 3.2 and 3.8 Ghz microwave frequencies to an external receiver. After a two-hour charge, delivered wirelessly through the scalp via induction, it can operate for more than six hours.

“The device uses less than 100 milliwatts of power, a key figure of merit,” Nurmikko said.

Co-author Ming Yin, a Brown postdoctoral scholar and electrical engineer, said one of the major challenges that the team overcame in building the device was optimizing its performance given the requirements that the implant device be small, low-power and leak-proof, potentially for decades.

“We tried to make the best tradeoff between the critical specifications of the device, such as power consumption, noise performance, wireless bandwidth and operational range,” Yin said. “Another major challenge we encountered was to integrate and assemble all the electronics of the device into a miniaturized package that provides long-term hermeticity (water-proofing) and biocompatibility as well as transparency to the wireless data, power, and on-off switch signals.”

With early contributions by electrical engineer William Patterson at Brown, Yin helped to design the custom chips for converting neural signals into digital data. The conversion has to be done within the device, because brain signals are not produced in the ones and zeros of computer data.

Ample applications

The team worked closely with neurosurgeons to implant the device in three pigs and three rhesus macaque monkeys. The research in these six animals has been helping scientists better observe complex neural signals for as long as 16 months so far. In the new paper, the team shows some of the rich neural signals they have been able to record in the lab. Ultimately this could translate to significant advances that can also inform human neuroscience.

Current wired systems constrain the actions of research subjects, Nurmikko said. The value of wireless transmission is that it frees subjects to move however they intend, allowing them to produce a wider variety of more realistic behaviors. If neuroscientists want to observe the brain signals produced during some running or foraging behaviors, for instance, they can’t use a cabled sensor to study how neural circuits would form those plans for action and execution or strategize in decision making.

In the experiments in the new paper, the device is connected to one array of 100 cortical electrodes, the microscale individual neural listening posts, but the new device design allows for multiple arrays to be connected, Nurmikko said. That would allow scientists to observe ensembles of neurons in multiple related areas of a brain network.

The new wireless device is not approved for use in humans and is not used in clinical trials of brain-computer interfaces. It was designed, however, with that translational motivation.

“This was conceived very much in concert with the larger BrainGate* team, including neurosurgeons and neurologists giving us advice as to what were appropriate strategies for eventual clinical applications,” said Nurmikko, who is also affiliated with the Brown Institute for Brain Science.

Borton is now spearheading the development of a collaboration between EPFL and Brown to use a version of the device to study the role of the motor cortex in an animal model of Parkinson’s disease.

Meanwhile the Brown team is continuing work on advancing the device for even larger amounts of neural data transmission, reducing its size even further, and improving other aspects of the device’s safety and reliability so that it can someday be considered for clinical application in people with movement disabilities.

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Two Dutch men get to experience the pain of contractions via electrodes.

An electroencephalogram (EEG) is a test that records electrical activity in the brain. Brain cells create tiny electrical impulses for communicating with each other. The EEG picks up these impulses through tiny wires (electrodes) placed on your scalp. The impulses are amplified and digitally recorded by a computer. The recordings look like wavy lines (sometimes called brain waves). An EEG may be done when you are awake, asleep, or both.

An EEG is usually done to see if a person is having seizures, and if so, what type of seizures they are. The EEG can also look for changes in brain activity caused by head injury, tumor, infection, or other problems that affect the brain. In addition, an EEG may be used to evaluate brain activity in someone who is unconscious or in a coma.

Prior to having the EEG done, you must avoid having caffeine and taking medicines that affect the nervous system. Once the electrodes are attached and the computer is recording, you may be asked to do things like open or close your eyes, or change your breathing to fast or slow. You might be exposed to bright or flashing lights or noise. The EEG usually takes about an hour. If the EEG is done while you are sleeping, it usually takes about 3 hours.