Tag Archives: electroencephalography (EEG)

Prosthetic pain

“Feeling no pain” can be a euphemism for being drunk. However, there are some people for whom it’s not a euphemism and they literally feel no pain for one reason or another. One group of people who feel no pain are amputees and a researcher at Johns Hopkins University (Maryland, US) has found a way so they can feel pain again.

A June 20, 2018 news item on ScienceDaily provides an introduction to the research and to the reason for it,

Amputees often experience the sensation of a “phantom limb” — a feeling that a missing body part is still there.

That sensory illusion is closer to becoming a reality thanks to a team of engineers at the Johns Hopkins University that has created an electronic skin. When layered on top of prosthetic hands, this e-dermis brings back a real sense of touch through the fingertips.

“After many years, I felt my hand, as if a hollow shell got filled with life again,” says the anonymous amputee who served as the team’s principal volunteer tester.

Made of fabric and rubber laced with sensors to mimic nerve endings, e-dermis recreates a sense of touch as well as pain by sensing stimuli and relaying the impulses back to the peripheral nerves.

A June 20, 2018 Johns Hopkins University news release (also on EurekAlert), which originated the news item, explores the research in more depth,

“We’ve made a sensor that goes over the fingertips of a prosthetic hand and acts like your own skin would,” says Luke Osborn, a graduate student in biomedical engineering. “It’s inspired by what is happening in human biology, with receptors for both touch and pain.

“This is interesting and new,” Osborn said, “because now we can have a prosthetic hand that is already on the market and fit it with an e-dermis that can tell the wearer whether he or she is picking up something that is round or whether it has sharp points.”

The work – published June 20 in the journal Science Robotics – shows it is possible to restore a range of natural, touch-based feelings to amputees who use prosthetic limbs. The ability to detect pain could be useful, for instance, not only in prosthetic hands but also in lower limb prostheses, alerting the user to potential damage to the device.

Human skin contains a complex network of receptors that relay a variety of sensations to the brain. This network provided a biological template for the research team, which includes members from the Johns Hopkins departments of Biomedical Engineering, Electrical and Computer Engineering, and Neurology, and from the Singapore Institute of Neurotechnology.

Bringing a more human touch to modern prosthetic designs is critical, especially when it comes to incorporating the ability to feel pain, Osborn says.

“Pain is, of course, unpleasant, but it’s also an essential, protective sense of touch that is lacking in the prostheses that are currently available to amputees,” he says. “Advances in prosthesis designs and control mechanisms can aid an amputee’s ability to regain lost function, but they often lack meaningful, tactile feedback or perception.”

That is where the e-dermis comes in, conveying information to the amputee by stimulating peripheral nerves in the arm, making the so-called phantom limb come to life. The e-dermis device does this by electrically stimulating the amputee’s nerves in a non-invasive way, through the skin, says the paper’s senior author, Nitish Thakor, a professor of biomedical engineering and director of the Biomedical Instrumentation and Neuroengineering Laboratory at Johns Hopkins.

“For the first time, a prosthesis can provide a range of perceptions, from fine touch to noxious to an amputee, making it more like a human hand,” says Thakor, co-founder of Infinite Biomedical Technologies, the Baltimore-based company that provided the prosthetic hardware used in the study.

Inspired by human biology, the e-dermis enables its user to sense a continuous spectrum of tactile perceptions, from light touch to noxious or painful stimulus. The team created a “neuromorphic model” mimicking the touch and pain receptors of the human nervous system, allowing the e-dermis to electronically encode sensations just as the receptors in the skin would. Tracking brain activity via electroencephalography, or EEG, the team determined that the test subject was able to perceive these sensations in his phantom hand.

The researchers then connected the e-dermis output to the volunteer by using a noninvasive method known as transcutaneous electrical nerve stimulation, or TENS. In a pain-detection task, the team determined that the test subject and the prosthesis were able to experience a natural, reflexive reaction to both pain while touching a pointed object and non-pain when touching a round object.

The e-dermis is not sensitive to temperature–for this study, the team focused on detecting object curvature (for touch and shape perception) and sharpness (for pain perception). The e-dermis technology could be used to make robotic systems more human, and it could also be used to expand or extend to astronaut gloves and space suits, Osborn says.

The researchers plan to further develop the technology and better understand how to provide meaningful sensory information to amputees in the hopes of making the system ready for widespread patient use.

Johns Hopkins is a pioneer in the field of upper limb dexterous prostheses. More than a decade ago, the university’s Applied Physics Laboratory led the development of the advanced Modular Prosthetic Limb, which an amputee patient controls with the muscles and nerves that once controlled his or her real arm or hand.

In addition to the funding from Space@Hopkins, which fosters space-related collaboration across the university’s divisions, the team also received grants from the Applied Physics Laboratory Graduate Fellowship Program and the Neuroengineering Training Initiative through the National Institute of Biomedical Imaging and Bioengineering through the National Institutes of Health under grant T32EB003383.

The e-dermis was tested over the course of one year on an amputee who volunteered in the Neuroengineering Laboratory at Johns Hopkins. The subject frequently repeated the testing to demonstrate consistent sensory perceptions via the e-dermis. The team has worked with four other amputee volunteers in other experiments to provide sensory feedback.

Here’s a video about this work,

Sarah Zhang’s June 20, 2018 article for The Atlantic reveals a few more details while covering some of the material in the news release,

Osborn and his team added one more feature to make the prosthetic hand, as he puts it, “more lifelike, more self-aware”: When it grasps something too sharp, it’ll open its fingers and immediately drop it—no human control necessary. The fingers react in just 100 milliseconds, the speed of a human reflex. Existing prosthetic hands have a similar degree of theoretically helpful autonomy: If an object starts slipping, the hand will grasp more tightly. Ideally, users would have a way to override a prosthesis’s reflex, like how you can hold your hand on a stove if you really, really want to. After all, the whole point of having a hand is being able to tell it what to do.

Here’s a link to and a citation for the paper,

Prosthesis with neuromorphic multilayered e-dermis perceives touch and pain by Luke E. Osborn, Andrei Dragomir, Joseph L. Betthauser, Christopher L. Hunt, Harrison H. Nguyen, Rahul R. Kaliki, and Nitish V. Thakor. Science Robotics 20 Jun 2018: Vol. 3, Issue 19, eaat3818 DOI: 10.1126/scirobotics.aat3818

This paper is behind a paywall.

Montreal Neuro goes open science

The Montreal Neurological Institute (MNI) in Québec, Canada, known informally and widely as Montreal Neuro, has ‘opened’ its science research to the world. David Bruggeman tells the story in a Jan. 21, 2016 posting on his Pasco Phronesis blog (Note: Links have been removed),

The Montreal Neurological Institute (MNI) at McGill University announced that it will be the first academic research institute to become what it calls ‘Open Science.’  As Science is reporting, the MNI will make available all research results and research data at the time of publication.  Additionally it will not seek patents on any of the discoveries made on research at the Institute.

Will this catch on?  I have no idea if this particular combination of open access research data and results with no patents will spread to other university research institutes.  But I do believe that those elements will continue to spread.  More universities and federal agencies are pursuing open access options for research they support.  Elon Musk has opted to not pursue patent litigation for any of Tesla Motors’ patents, and has not pursued patents for SpaceX technology (though it has pursued litigation over patents in rocket technology). …

Montreal Neuro and its place in Canadian and world history

Before pursuing this announcement a little more closely, you might be interested in some of the institute’s research history (from the Montreal Neurological Institute Wikipedia entry and Note: Links have been removed),

The MNI was founded in 1934 by the neurosurgeon Dr. Wilder Penfield (1891–1976), with a $1.2 million grant from the Rockefeller Foundation of New York and the support of the government of Quebec, the city of Montreal, and private donors such as Izaak Walton Killam. In the years since the MNI’s first structure, the Rockefeller Pavilion was opened, several major structures were added to expand the scope of the MNI’s research and clinical activities. The MNI is the site of many Canadian “firsts.” Electroencephalography (EEG) was largely introduced and developed in Canada by MNI scientist Herbert Jasper, and all of the major new neuroimaging techniques—computer axial tomography (CAT), positron emission tomography (PET), and magnetic resonance imaging (MRI) were first used in Canada at the MNI. Working under the same roof, the Neuro’s scientists and physicians made discoveries that drew world attention. Penfield’s technique for epilepsy neurosurgery became known as the Montreal procedure. K.A.C. Elliott identified γ-aminobutyric acid (GABA) as the first inhibitory neurotransmitter. Brenda Milner revealed new aspects of brain function and ushered in the field of neuropsychology as a result of her groundbreaking study of the most famous neuroscience patient of the 20th century, H.M., who had anterograde amnesia and was unable to form new memories. In 2007, the Canadian government recognized the innovation and work of the MNI by naming it one of seven national Centres of Excellence in Commercialization and Research.

For those with the time and the interest, here’s a link to an interview (early 2015?) with Brenda Milner (and a bonus, related second link) as part of a science podcast series (from my March 6, 2015 posting),

Dr. Wendy Suzuki, a Professor of Neural Science and Psychology in the Center for Neural Science at New York University, whose research focuses on understanding how our brains form and retain new long-term memories and the effects of aerobic exercise on memory. Her book Healthy Brain, Happy Life will be published by Harper Collins in the Spring of 2015.

  • Totally Cerebral: Untangling the Mystery of Memory: Neuroscientist Wendy Suzuki introduces us to scientists who have uncovered some of the deepest secrets about our brains. She begins by talking with experimental psychologist Brenda Milner [interviewed in her office at McGill University, Montréal, Quebéc], who in the 1950s, completely changed our understanding of the parts of the brain important for forming new long-term memories.
  • Totally Cerebral: The Man Without a Memory: Imagine never being able to form a new long term memory after the age of 27. Welcome to the life of the famous amnesic patient “HM”. Neuroscientist Suzanne Corkin studied HM for almost half a century, and gives us a glimpse of what daily life was like for him, and his tremendous contribution to our understanding of how our memories work.

Brief personal anecdote
For those who just want the science, you may want to skip this section.

About 15 years ago, I had the privilege of talking with Mary Filer, a former surgical nurse and artist in glass. Originally from Saskatchewan, she, a former member of Wilder Penfield’s surgical team, was then in her 80s living in Vancouver and still associated with Montreal Neuro, albeit as an artist rather than a surgical nurse.

Penfield had encouraged her to pursue her interest in the arts (he was an art/science aficionado) and at this point her work could be seen many places throughout the world and, if memory serves, she had just been asked to go MNI for the unveiling of one of her latest pieces.

Her husband, then in his 90s, had founded the School of Architecture at McGill University. This couple had known all the ‘movers and shakers’ in Montreal society for decades and retired to Vancouver where their home was in a former chocolate factory.

It was one of those conversations, you just don’t forget.

More about ‘open science’ at Montreal Neuro

Brian Owens’ Jan. 21, 2016 article for Science Magazine offers some insight into the reason for the move to ‘open science’,

Guy Rouleau, the director of McGill University’s Montreal Neurological Institute (MNI) and Hospital in Canada, is frustrated with how slowly neuroscience research translates into treatments. “We’re doing a really shitty job,” he says. “It’s not because we’re not trying; it has to do with the complexity of the problem.”

So he and his colleagues at the renowned institute decided to try a radical solution. Starting this year, any work done there will conform to the principles of the “open-
science” movement—all results and data will be made freely available at the time of publication, for example, and the institute will not pursue patents on any of its discoveries. …

“It’s an experiment; no one has ever done this before,” he says. The intent is that neuroscience research will become more efficient if duplication is reduced and data are shared more widely and earlier. …”

After a year of consultations among the institute’s staff, pretty much everyone—about 70 principal investigators and 600 other scientific faculty and staff—has agreed to take part, Rouleau says. Over the next 6 months, individual units will hash out the details of how each will ensure that its work lives up to guiding principles for openness that the institute has developed. …

Owens’ article provides more information about implementation and issues about sharing. I encourage you to read it in its entirety.

As for getting more research to the patient, there’s a Jan. 26, 2016 Cafe Scientifique talk in Vancouver (my Jan. 22, 2016 ‘Events’ posting; scroll down about 40% of the way) regarding that issue although there’s no hint that the speakers will be discussing ‘open science’.