Day: July 11, 2021

Categories : Implants and Prostheses Medical Research & TechnologyTags :

Carbon Fibre Electrodes Allow Unprecedented Neural Recording

On By ModernMedia
Image by Robina Weemeijer on Unsplash

A tiny, implantable carbon fibre electrode has the potential to provide a long-term brain-computer interface which can record electrical signals over lengthy periods of time.

The carbon fibre electrodes were developed at the University of Michigan and demonstrated in rats. The new research shows the promise of carbon fibre electrodes in recording electrical signals from the brain without damaging brain tissue. Directly implanting carbon fiber electrodes into the brain allows the capturing of bigger and more specific signals than current technologies.

This technology could lead to advances that could give amputees and those with spinal injuries control of advanced prosthetics, stimulate the sacral nerve to restore bladder control, stimulate the cervical vagus nerve to treat epilepsy and provide deep brain stimulation as a possible treatment for Parkinson’s.  

“There are interfaces out there that can be implanted directly into the brain but, for a variety of reasons, they only last from months to a few years,” said Elissa Welle, a recent PhD graduate from the U-M Department of Biomedical Engineering. “Any time you’re opening up the skull for a procedure involving the brain, it’s a big deal.”

Brain implants are typically made from silicon due to its ability to conduct electricity and its historic use in cleanroom technology. But silicon is not very biocompatible and leads to the formulation of scar tissue over long periods. Such electodes will eventually degrade and no longer capture brain signals, requiring removal.

Carbon fibres may be the answer to getting high-quality signals with an interface that lasts years, not months. And by laser cutting and sharpening carbon fibers into tiny, subcellular electrodes in the lab with the help of a small blowtorch, U-M engineers have harnessed the potential for excellent signal capture in a form the body is more likely to accept.

“After implantation, it sits inside the brain in a way that does not interfere with the surrounding blood vessels, because it’s smaller than those blood vessels,” Welle said. “They’ll move around and adjust to an object that small, rather than get torn as they would when encountering larger implants.”

Part of the electrode’s compatibility in brain tissue is down to smaller size, but its needle-like shape may also minimise compacting of any surrounding tissue. Larger carbon-based electrodes have been shown to actually encourage neural tissue to grow instead of degrading. The team is hopeful that similar potential for their carbon fibre electrodes will be revealed by further testing.

Carbon fibre electrodes in a previous study dramatically outperformed conventional silicon electrodes with 34% of electrodes recording a neuron signal compared to 3%. Laser cutting then improved this number to 71% at 9 weeks after implantation. Flame sharpening has now enabled these high performance probes to be implanted directly into the cerebral cortex, negating the need for a temporary insertion aid, or shuttle, as well as into the rat’s cervical vagus nerve.

It is relatively easy to insert electrodes into the brain. But the researchers have also taken on the more difficult task of inserting the sharpened carbon fibre electrodes into nerves, with micrometre diameters.

Those findings show that potential for these electrodes goes beyond prosthetic manipulation, according to Cindy Chestek, a U-M associate professor of biomedical engineering, and principal investigator of the The Cortical Neural Prosthetics Lab.

“Someone who is paralysed may have no control over things like their bladder, for example,” Prof Chestek said. “We may be able to utilise these smaller electrodes to stimulate and record signals from areas that can’t be reached by larger ones, maybe the neck or spinal cord, to help give patients some level of control.”

Source: University of Michigan

Categories : COVID General InterestTags :

Kids Cunningly Spoof COVID Tests to Skip School

On By ModernMedia
Photo by Greenvalley Pictures on Unsplash

School children in the UK have found an ingenious way to get out of school — by deliberately compromising COVID tests using soft drinks or fruit juice to produce false positives.

Children returned to in-person learning in March in the UK, with regular COVID testing to monitor for infection and infected students being sent home. 

However, after three months of regular testing, a school in Merseyside had reports of students who had found that either drinking fruit-flavored juice or misusing them as an analyte had the potential to provide a false-positive result.  

The trick involves “spoofing” a lateral flow device (LFD) which is designed to detect COVID antibodies.

LFDs come in the form of cartridges containing a nitrocellulose membrane strip and absorbent paper with dried test reagents affixed, which include antibodies labelled with gold particles for visibility. When these reagents are mixed with the analyte from a test sample, they migrate through the nitrocellulose strip and over the test (T) line where the SARS-CoV-2 monoclonal antibody is located.

A key part of the trick is not mixing the sample fluid with the buffer, BBC’s Mark Lorch found.

The liquid buffer solution maintains an ideal pH for the antibodies, and is key to the correct function of the test. The critical role of the buffer is highlighted by if cola is mixed with the buffer, then the LFDs behave correctly, returning a negative result for COVID.

Without the buffer, the antibodies in the test are fully exposed to the acidic pH of the beverages. And this has a dramatic effect on their structure and function. Proteins such as antibodies fold up into very specific structures, and even a small change to the chains can dramatically impact a protein’s function. Changing the pH could cause the antibodies used in the test to no longer function correctly and incorrectly binding. By diluting the drink

In a study made available on the medRxiv preprint server, researchers tested the ability of various types of soft drinks to produce false positive results. They found that the presence of sugar and acidity was necessary to produce the false positives. The researchers also recommended 

Source: BBC News

Categories : Cardiovascular DiseaseTags :

Listening to Vocal Music Aids in Stroke Patient Rehabilitation

On By ModernMedia
Photo by Adrian Korte on Unsplash

Research has shown that listening to music with singing daily aids language recovery in stroke patients. However, the neural mechanisms behind the phenomenon have remained unknown thus far.

Researchers at the University of Helsinki and the Turku University Hospital Neurocentre compared the effect of listening to vocal music, instrumental music and audiobooks on the structural and functional recovery of the language network of patients who had suffered an acute stroke. The study also investigated the links between such changes and language recovery during a three-month follow-up period.

The results showed that listening to vocal music improved the recovery of the structural connectivity of the language network in the left frontal lobe compared to listening to audiobooks. These structural changes correlated with the recovery of language skills.

“For the first time, we were able to demonstrate that the positive effects of vocal music are related to the structural and functional plasticity of the language network. This expands our understanding of the mechanisms of action of music-based neurological rehabilitation methods,” said Postdoctoral Researcher Aleksi Sihvonen.

Aphasia, a language impairment resulting from a stroke, is a source of considerable suffering for patients and their families. Current therapies aid the rehabilitation of language impairments, but the results are variable and the necessary rehabilitation is often not sufficiently available and early enough.

“Listening to vocal music can be considered a measure that enhances conventional forms of rehabilitation in healthcare. Such activity can be easily, safely and efficiently arranged even in the early stages of rehabilitation,” Sihvonen said.

According to Sihvonen, listening to music could inexpensively boost normal rehabilitation, or be an option for rehabilitating patients with mild speech disorders when other rehabilitation options are scarce.

After a disturbance of the cerebral circulation, the brain needs stimulation to make as good a recovery as possible. Conventional rehabilitation methods aim to provide this as well.

“Unfortunately, a lot of the time spent in hospital is not stimulating. At these times, listening to music could serve as an additional and sensible rehabilitation measure that can have a positive effect on recovery, improving the prognosis,” Sihvonen added.

Source: University of Helsinki

Journal information: Sihvonen, A.J., et al. (2021) Vocal Music Listening Enhances Poststroke Language Network Reorganization. eNeuro. doi.org/10.1523/ENEURO.0158-21.2021.

Categories : Mental HealthTags :

Social Media Breaks Don’t Relieve Boredom or Stress

On By ModernMedia
Photo by Tracy le Blanc from Pexels

A team of researchers has found that workers using their smartphone to take short breaks do not find reductions in boredom or fatigue. 

Smartphones have had an inescapable impact on society, and allow users to engage with a variety of apps. Anecdotal evidence also suggests that people use their phones in other ways as well, such as to alleviate boredom or to reduce stress. The researchers noted that many people use their smartphones to take short breaks from their work—and they wondered if doing so actually helped with boredom or reduced stress.

To find out, researchers at Radboud University’s Behavioural Science Institute in The Netherlands recruited 83 PhD candidates, each of whom were asked to report their level of boredom and fatigue every hour while they were working. They also received a smartphone app that logged its usage.

In comparing phone usage with self-reported levels of boredom and fatigue, the researchers were able to track the volunteers’ use of their phones to deal with boredom or fatigue. They found that not only did using their phones in such a manner not alleviate boredom or fatigue, in many cases it in fact made things worse. Volunteers who described themselves as more bored or more fatigued than others in the study did not take longer smartphone breaks than those feeling less bored or fatigued.

The researchers acknowledged that their study was small but their results suggest that workers might consider fatigue or boredom reducing alternatives. They noted also that some prior research has shown that boredom can sometimes be alleviated by engaging in activities that bring some degree of joy. They suggest that rather than mindlessly scrolling, they find ways to use their phones to bring them joy, such as by looking at pictures of loved ones.

Source: Medical Xpress

Journal information: Jonas Dora et al, Fatigue, boredom and objectively measured smartphone use at work, Royal Society Open Science (2021). DOI: 10.1098/rsos.201915