Best Online Resources to Understand Cell Division, Meiosis, & Mitosis


Although I am an illustrator, I am still always looking for beautifully prepared animations and illustrations. This one is an evocative display of cell division. If you didn’t already have a sense of the dramatic life of a cell, you will after watching this:

Cell Division and the Cell Cycle

This was a particularly complicated topic for me, as a student, and here are a few of the solutions I came up with long ago, for making the topic more clear to myself and my audience:

An original sketch, spermatogenesis, created large on several sheets, taped together:

Spermatogenesis Sketch © 1999 Laura Maaske
Spermatogenesis Sketch © 1999 Laura Maaske

Unfortunately, this is such an old illustration, I no longer have the layout software I used to prepare the text, Aldus Pagemaker. But I think the text, however misaligned, is still helpful to understand the process of cell replication and division:

© 1995 Laura Maaske. permatogenesis poster
© 1995 Laura Maaske. permatogenesis poster
Meiosis compared with Mitosis © 1999 Laura Maaske - Medimagery LLC
Meiosis compared with Mitosis © 1999 Laura Maaske – Medimagery LLC

Please offer your favorite online resource for learning about cell division, Meiosis and Mitosis.

Laura Maaske, B.Sc., M.Sc.BMC, Medical & Science Illustrator | e-Textbook Designer

November 20, 2013

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Ideas I’d like to Illustrate: any Takers?…


Recently I read that our digestive tract have more neurons than a domestic cat has in its whole brain. So when I read that microbes in our guts may be controlling the moods we experience in our brains, it came as not such a surprise. The particular strain of microbes in your gut may be responsible for emotional health as well as your physical health. They may determine your sense of fear or anxiety or relaxation and calm. Stephen Collins, McMaster University, Canada, was the first to make this connection, in his studies on rats. Research is being done on humans now, by UCLA’s Center for Neurobiology of Stress, Emeran Mayer, M.D.

I also remember learning in anatomy class that there are not many known or important functions for the vagus nerve. Since then, the vagus nerve comes up frequently in my reading, as a source of receiving emotional signals fron the gut. Dacher Keltner is another great resource for this understanding.

Ciick HERE to see the full article from Rob Stein of NPR.

And if you want to watch a fun and cute video on what microbes are doing in your guts, this is great for review or an introduction:

Lateral(800)Copyright
External Lateral Brain External Lateral Brain. Illustrated by Laura Maaske. @2000 Columbia EHC

Laura Maaske, B.Sc., M.Sc.BMC, Medical & Science Illustrator | e-Textbook Designer

November 18, 2013

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The Pull to the Countryside


Drawing Physicians to Rural America with the AHA

This October 1st opened enrollment of the Affordable Health Care Act (ACA), which is the most sweeping social change for Americans since the Social Security Act Roosevelt signed in in 1935. The AMA has praised this event as historic. And with the government taking a stronger control in healthcare, there will be a guiding hand.

One only need look at the news headlines and the Health Provider Shortage Areas (HPSAs) to understand that rural Americans face greater health risks than urban Americans. Only 10% of American physicians practice in rural areas, whereas rural regions compose 25% of the American population.

The ACA offers coverage to millions of otherwise uninsured Americans. Particularly, the change affects 60 million who live in rural areas of the United States. Presently, one out of every five uninsured Americans lives in a rural area, compared to one in six for the population at large. And because of lower income among rural residents compared to urban residents, there will be an even greater need for doctors to an area that has historically suffered a doctor shortage.

With 32 million Americans harnessing new access to healthcare, between 4,307 and 6,940 additional primary care physicians would be needed to accommodate this increase by 2019.

But despite the need for physicians in rural areas, the incentives have remained low. Physicians in rural areas perform tasks that would be performed by specialists in more urban areas. Call schedules remain a burden in rural areas, with a one in two or one in three call ratio. Educational resources are not available in rural areas to the degree they are in urban areas. Typically, even local physicians who want to practice in rural areas where they grew up must go out-of state to urban centers for residency, which has resulted in less interest among physicians to practice in rural hometowns.

How will the ACA bring physicians to rural areas?

Initiatives of the ACA to increase physician distribution to rural areas:

Increases competition among insurance providers, allowing the Health Insurance Marketplace to lower costs.

Authorizes funding for additional medical residency training programs through the Health Resources and Services Administration (HRSA) and the ACA’s own Prevention and Public Health Fund. Training would preferentially encourage primary care and general surgery. In general, the ACA will offer incentives to physicians for more necessary specializations. Presently, the ratio of primary care physicians is one-third, to two-thirds specialists. In a report completed this by the Congressional Research Service (CRS), this ratio is not in proportion to the health needs of patients.

Allocates money to increase the primary care workforce by training more doctors.

Requires that Medicare-funded residency training slots be redistributed from hospitals that are not using them or that have closed, to hospitals seeking to train additional residents.

Allocates a greater amount of money for scholarships and loans for all health professionals. It relieves the basic need for physicians by training an increased number of physician assistants and nurses.

Expands the number of general staff who work in rural health centers.

Increases the number of nurse-managed clinics at nursing schools where nurses in training treat rural patients.

Offers a 10 percent bonus, through 2015 for primary care doctors who offer services to Medicare patients.

Subsidizes loan repayment or offers education grants to professionals trained in undersupplied specialties such as pediatrics, mental health, geriatrics, behavior health, and general surgery, in exchange for serving in under-serviced areas.

Plans to increase physician productivity.

Encourages increased efficiency and coordination among all personnel in medical homes, clinics, and hospitals, as well as other care organizations.

Reduces isolation among physicians by offering access between rural centers and colleagues, and by increasing further continuing educational opportunities to rural physicians.

Establishes a National Health Care Workforce Commission to develop economic incentives and grants and contracts for physicians, encouraging greater support of primary care training and greater distribution to rural areas. This includes distributing Residency slots to rural areas. It also encourages physician training in community-based settings to offset the greater orientation toward specialty care in hospital-based residency training. This may be the most important aspect of the new law, as it creates a regulatory commission which will continue to promulgate rules and regulations to improve delivery of healthcare services.

For more information, read the Federal Office of Rural Health Policy report, “Office of Rural Health Policy Rural Guide to Health Professions Funding“. And for an in-depth definition of “rural”, visit the USDA Website page defining this term.

As the medical illustrator and editorial artist for Med Monthly, our publisher asked me to illustrate Med Monthly’s November 2013 cover. The Affordable Healthcare Act, with its shift in perspective towards rural America, brought me to wonder what are we looking to? What do we want from this initiative? Health insurance itself is not much more than 100 years old, in the U.S. But if we can accomplish this great aim to offer healthcare more equally to all Americans, urban or rural, we’ll be a fairer place to live, and a little bit closer to our ideals.

For the full article, visit MedMonthly Magazine HERE.

Laura Maaske

Can the AHA Draw Doctors the the Countryside? Illustrated by Laura Maaske; © 2013 Laura Maaske - Medimagery LLC
Can the AHA Draw Doctors the the Countryside? Illustrated by Laura Maaske; © 2013 Laura Maaske – Medimagery LLC

Laura Maaske, B.Sc., M.Sc.BMC, Writer & Illustrator

November 5, 2013

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Untying the Knot: Your Heart is actually a Spiral


The heart is, “an arrangement so unusual and perplexing,
that it has long been considered as forming a kind of Gordian knot in Anatomy.
Of the complexity of the arrangement I need not speak further than to say that
Vesalius, Albinus, Haller and De Blainville,
all confessed their inability to unravel it”.
James Bell Pettigrew, 1834-1908
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If anyone suggests to you that science, particularly biological science and medicine, is not beautiful and not much more than “a dissection”, as someone once said to me, I could offer you a place to begin… a place of great beauty to point to.

It is one of the fascinating details of evolutionary embryology that I loved learning as a student: the vertebrate heart evolved from a single simple tube into the complex structure we know as our heart. Here is the heart of a human embryo before two weeks:

Tubular heart. Lithograph from the 20th U.S. edition of Gray's Anatomy of the Human Body, originally published in 1918. License is in the public domain because its copyright has expired.
Tubular heart of human embryo before 14 days.
Lithograph from the 20th U.S. edition of Gray's Anatomy of the Human Body, originally published in 1918. License is in the public domain because its copyright has expired.
Human embryonic heart. 14 day old.

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Here is great old animation depicting the human heart formation:

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Circulation functions with a “two-chambered” heart in fish, as you can see in this illustration:

This is a file from the Wikimedia Commons and is licensed freely.
“Two-chambered” heart of fish.

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It is a three-chambered in amphibians and reptiles. And it is four-chambered in mammals and birds.

Four Chambered Adult Human Heart. Illustrated by Laura Maaske.
Four Chambered Adult Human Heart. Illustrated by Laura Maaske.

For further comparison, visit these pages which offer comparative imagery: Fish, amphibian, and mammalian hearts, and Fish, amphibian, reptile, and mammal & bird hearts.

During my undergraduate coursework in zoology, this evolution had stuck me as beautiful, that organisms tend towards complexity in their evolution. Later, as a student in biomedical communications at the University of Toronto, I found heart dissections reveal beautifully complicated anatomy compared to what I’d seen in the fish just a few years before.

In fact, while embryologists understood this folding pattern by observing cardiac development, it wasn’t until 2006 that the anatomist Torrent Guasp, using a special technique, dissected the human heart for the first time in history. In this skillful dissection he uncovered the original embryonic tube structure. Here is a video explaining Torrent Guasp’s dissection:

“When I looked at the heart for the first time I saw a circumferential basal loop. And then I saw a descending limb and an ascending limb. And they curl around each other at a helix and a vortex, except for the ventricle. And the angles at which they go is about 60 degrees. 60 degrees down and 60 degrees going up, and they cross each other in that way. For years people had wondered why this happened. I realized this is really a spiral. And I began to think about spirals. And I began to understand that spirals are almost the master plan of nature in terms of structure and in terms of rhythm.… if you pick the middle of the spiral up you form a helix. And of course the heart is a helix.”
-Dr. Gerald Buckberg, M.D.
 

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So, for one of my own favorite illustration projects, I began my work by researching this folding pattern, and drawing its reach into the heart. As you can see, the folding works a little bit like a knot, and it is also a two-ended spiral.

cardiovascular_bands
The folding structure of the heart

Mar102013_0703

I made a sample out of clay and practiced the folding pattern.

Mar102013_iph_0728 Mar102013_0701

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And here are my illustrations to reveal the tubular unfolding pattern of the human heart:

Revealing embryology
Unfolding the Heart 1
Revealing embryology
Unfolding the Heart 2
Revealing embryology
Unfolding the Heart 3
Revealing embryology
Unfolding the Heart 4
Revealing embryology
Unfolding the Heart 5

As you can see in these illustrations, the adult human heart in its evolved form is a flattened tube, and behaves like a rope as the muscles wrap and squeeze blood. But it is a very complex knot, the dissection of which was not even achieved until the past few years, with Torrent Guasp. How remarkable that a structure so complex can be reduced, backwards, so that its simpler origin is apparent.

Gor·di·an knot
ˈgôrdēən/
noun
noun: Gordian knot; plural noun: Gordian knots
1. an extremely difficult or involved problem.
Origin
mid 16th cent.:
from the legend that Gordius,
king of Gordium,
tied an intricate knot and prophesied that
whoever untied it would become the ruler of Asia.
It was cut through with a sword by Alexander the Great.

Laura Maaske, B.Sc., M.Sc.BMC, Medical Illustrator & Designer

October 29, 2013

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Flipping the Medical School Classroom


The high-tech future of medical education

Was your medical training all you had hoped it to be? Did you learn as much as you expected or knew you could? Was learning effective, efficient, and fun? Technology is changing the practice of medicine. But it is also changing the way medical students learn, expectations of their potential, and the way they want to be learning.

A Changing World

AMA outlines a need for change in medical education

Medical education cannot remain the same, given the changing world. According to James L. Madara AMA EVP and CEO, there is gap between what students are learning, and the everyday reality of practicing as a physician[1]. In fact, the AMA is taking suggestions as models for this change, and has funded a number of schools to begin to reform standards in medical education.

To instigate practical change, he American Medical Association is granting $11 million in the course of five years to a list of winning medical schools that will explore teaching innovations. These schools must come up with better offerings for individual learning styles, methods to assess core competencies, improving patient outcomes and safety, and better efficiencies health care financing.

Grant recipients for this initiative, named Accelerating Change in Medical Education, include,

  • Indiana University School of Medicine
  • Mayo Medical School
  • NYU School of Medicine
  • Oregon Health & Science University School of Medicine
  • Penn State University College of Medicine
  • The Brody School of Medicine at East Carolina University
  • The Warren Alpert Medical School of Brown University
  • University of California – Davis School of Medicine
  • University of California – San Francisco School of Medicine
  • University of Michigan Medical School
  • Vanderbilt University School of Medicine

To read a summary of the proposal offered by each school, visit the AMA Grant Projects Webpage[2].

What Endures in Education?

Plato was right

We all know better than to say because a learning strategy is new, it is better. So how do we judge? Educators create exhaustive studies to answer this question. And their insights offer us a few points of focus as we look through the filter of new technology to see how education might be improved. Reading and collecting ideas about education, through my own effort to create good ebooks for students, I have gathered a list of keys to good education:

  1. Individualized learning. This seems like a new idea. But formal education is new in human history. Before the Egyptians introduced formal education, 3000-5000 BCE[3], people learned person-to-person. So all education was individualized. Formal education offered efficiency. But more recently, educators are making the effort to allow students options to learning, so that their individual needs and preferences might be addressed. In studies of medical students preferred learning styles, it was found that students prefer that instruction to be offered in all avaiable formats (visual, audio, reading/writing, and kinisthetic) rather than one or another[4].
  2. Socratic method. Perhaps the greatest innovation in education came from Socrates. The Socratic method is way of teaching so that the student systematically explores a question. Through active thinking, the student finds answers.
  3. The lecture. Plato did not believe the written word was the best form of transmitting knowledge, and he suggested the oral tradition as the best way to learn[5][6]. Certainly his students would have had to take notes in order to have any record of all as to what was taught. Socrates, as well, felt that the implementation of written texts would weaken the mental faculties of students, who would no longer be inclined to commit ideas to memory[7]. The word itself, “lecture” is a 14th Century Latin word, which means, “to read” from a text. But this is not what students need today, and the traditional 45 minute lecture has been shown to be too long for a student’s attention span. 20 minutes works best for adults[8]. It must be modified to be effective. And it is typical for most people, that their minds wander during a lecture[9].
  4. The textbook. Although the Greeks used texts for learning. And while Gutenberg printed a few Latin books on his presses. The use of textbooks in formal education did not begin until the 19th Century[10].
  5. Repetition. Repetition as a key to learning dates back to the earliest forms of edcuation. However, it takes on a new possibility in the classroom. More recently, as students are using the computer and “flip the classroom” lectures as a way to review lecture materials, students find it extremely easy to review the materials that they find challenging. It has even reduced the need for students to ask professors questions outside class.This has been shown to be one of the most exciting innovations with technology, and it has freed time for professors to use in class to engage in less lecture-based and more Socratic forms of interaction with students.
  6. Practical Immersion. Apprenticeship is the traditional and enduring environment for hands-on learning. Many professions require internship. While many of these skills cannot be replicated in the digital environment, still many can be with simulated three-dimensional “worlds”.
  7. Interactive design. This really follows fromt the Socratic Method, as an ideal which enourages students to think and solve problems as a way of gaining deeper knowledge and understanding. Interactive, active rather than passive engagemnt with information, is best form of learning that can be offered to students.
  8. Fun, engagement, and interest. Traditionally, these goals were considered a luxury or frivolity in education. But more recently, educators are offering these aims as objectives in learning. As we all know, when we enjoy our work, when we become absorbed and engaged, and whatever helps us to focus our efforts, will make learning possible. Global learning, offered int he digital age, offers not just interactivity, but the possibility for great and interesting educators who are fantastic at teaching to reach extremely wide audiences and experience world recognition in a way teachers and professors rarely have before.
  9. Tests or markers of knowledge. Controversial as tests may be as a tool to measure knowledge, they are nonetheless an eduring method for self- and outside-assessment. With technology, increasingly it is becoming possible to test student remorely. This brings education closer to a one-world classroom.
hand_anatomy_app
We’re working on apps, here at Medimagery. This is a layered hand app to reveal layers of anatomy with the touch of a finger.

Keeping education goals in mind

What do we want our new doctors to be capable of?

Among the suggestions for using technology to make education better, medical schools offer these goals to keep in mind:

  1. Possess strong foundation of science with ability to use scientific method to seek new knowledge, and to critically evaluate medical literature
  2. Know the human body: cell and organ structure and function, system function and integration
  3. Understand molecular, genetic, biochemical, and cellular processes as they relate to human body
  4. Know determinants of human health and disease: personal, social, or environmental impacts; apply principles of pharmacology and therapeutics
  5. Safely perform routine diagnostic and therapeutic procedures
  6. Interpret routine laboratory results, clinical tests, and image scans related to common conditions and illnesses
  7. Skillfully perform physical and psychiatric examinations
  8. Formulate appropriate management strategies for patients, suitable to that patient’s needs and values
  9. Curiosity and passion to address future needs of society from a health perspective
  10.  Learn in a self-directed way with lifelong commitment to learning
  11.  Capacity to collaborate well and communicate clearly
  12.  Capacity for reflective practice, to recognize one’s own limitations, to improve one’s own performance
  13.  Exercise sound clinical reasoning and decision-making skills; to perform critical evaluations of healthcare situation and systems
  14.  Professionalism and leadership skills
  15.  Capacity to interpret and apply evidence, to interpret clinical information
  16.  Creativity: to produce new discoveries, to assimilate new information, and to apply this information to patient care
  17.  High ethical standards; Recognize, anticipate and navigate ethical dilemmas in medical care.
  18.  Empathy towards others and understanding of others’ needs; advocate for the interests of their patients.
  19.  Ability to gather the necessary information from patient history, to understand socioeconomic and cultural impacts, to accurately write a patient history, and then to correctly interpret this information
  20. Understand and utilize the healthcare in context as a larger system

So what changes are taking place now?

New possibilities emerge as a result of technology

“Born-digital” textbooks and learning materials are those which have been originally created in a digital format. They offer a full range of necessary features to make learning all the objectives of the course possible. These include interactive features to test principles and formulas being described, video clips to augment learning, and an audio track of the book text.

Schools are still in an embryonic stage, to be taking full advantage of technology that is offered today. In a survey of 940 bookstores, run by the Follett Higher Education Group, roighly 2% of tge textbooks sold at college bookstores are in a born-digital format[11].

Among schools making the transition, Stanford School of Medicine is taking a lead. Its goals are to reinvigorate the classroom by offering online lectures in short segments. These lectures are offered my many instructors and specialists in the field, as needed. This allows textbooks to pull from primart sources for knowledge. Short lectures are followed up with quizzes.

The classroom time then is freed up. It becomes a place for discussions rather than lectures. Students take more initiative in asking questions so learning can be individuized. Time traditionally spent in lecture is now spent in real-world application, problem-solving, case studies, and team-based endevors.

The new paradigm offers a growing possibility for academic superstars. Stanford Medical School relies on input from Salman Khan[12], famous for his engaging style in teaching subjects from math to art history, to help faculty make their presentations more interesting and engaging. Khan says, “I have a self-paced lecture to be seen at home… and what used to be homework, I now have students doing in the classroom.”

But medical schools cannot accomplish this alone. Textbook publishers play an enormous part in offering content. Innovative digital textbook company Kno has introduced, “Kno Me.” It’s a personalized dashboard which allows students to mark their performance, time commitment, and engagement with materials, in mastering content.

Textbook publishing giant, McGraw Hill, recently announced a plan that offers a place for textbooks in the changing medical classroom. This Spring it has begun to offer a textbook suite with “adaptive learning technology”, which means it collects data on individual student comprehension (knowledge, skill, and confidence). It uses this data to create algorithms for customized study. The program also offers “before-the-course” materials to help students warm-up before difficult classes. It includes photo-realistic virtual labs to make preparation for labs more effective. The book “talks” to students, offering instructions and suggestions on the most effective way to read, based on the student’s needs and performance. This textbook is not groundbreaking, but it is a good step forward.

The new changes put students in the powerful position to make critical suggestions, and of demanding that their educational content be effective. New materials should be available easily to all devices, probably Web-based. Content should be updated frequently and as soon as facts change. The books should be as interactive in teaching concepts and in testing them, encouraging critical thinking skills in the time-proven Socratic style.

Instructors should have greater impact as well, trusting that the material is peer-reviewed and authoritative. Instructors will have the freedom to choose which chapters and segments of material to be included in a course. Both students and faculty will be able to make use of the analytical capabilities of Smartbooks as a method of assessing their effectiveness in student learning.


[1] AMA pledges millions to jump-start innovation in medical education, By Kevin B. O’Reilly. Jan. 28, 2013http://www.amednews.com/article/20130128/profession/130129956/6/

[2] Proposals offered by each school can be viewed at http://www.ama-assn.org/sub/accelerating-change/grant-projects.shtml

[3] Formal education introduced by Egyptians. http://en.wikipedia.org/wiki/Education#History

[4] Heidi L. Lujan and Stephen E. DiCarlo. First-year medical students prefer multiple learning styles. 10 October 2005. http://advan.physiology.org/content/30/1/13.full

[5] Plato advising the oral tradition as the best: http://people.ucalgary.ca/~dabrent/webliteracies/platowr

[6] Plato’s Seventh Letter advising the oral tradition over written for passing significant knowledge, 360 BCE. http://classics.mit.edu/Plato/seventh_letter.html

[7] Socrates discourages written text as detrimental to learning. http://en.wikipedia.org/wiki/Textbook#History

[8] Joan Middendorf and Alan Kalish. The Change-up in Lectures. 1995. http://www.iub.edu/~tchsotl/part3/Middendorf%20&%20Kalish.pdf

[9] Rick Nauert. Short Lectures, Frequent Quizzes Maximize Online Learning. April 8, 2013. http://psychcentral.com/news/2013/04/08/short-lectures-frequent-quizzes-maximize-online-learning/53562.html

[10] Textbooks become standardized in formal education. http://en.wikipedia.org/wiki/Textbook#History

[11] Jeffrey R. Young. The Object Formerly Known as the Textbook. January 27, 2013.https://chronicle.com/article/Dont-Call-Them-Textbooks/136835/

[12] http://www.youtube.com/user/khanacademy

 
 

– See my full original article in Med Monthly Magazine at: http://medmonthly.com/research-technology/flipping-the-medical-classroom/#!

Laura Maaske, July 2013 • Medimagery Medical Illustration & Design
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Science Fiction No Longer


Reality: Mind-controlled Limbs

Written by  on September 30, 2013 in FeaturesSlide – No comments

They’re Here!

An early September morning, apples ripe out my window. I was speaking with Dr. Albert Chi, a pioneering surgeon for advanced prosthetics procedures at the Trauma Motor Control Research Division of Trauma and Critical Care, Johns Hopkins. Dr. Chi has been perfecting a surgical technique, called TMR, Targeted Muscle Reinnervation, for patients who have lost most of their upper limbs. Patients include those who have lost their arms to amputation above the level of the elbow, and also patients who have experienced shoulder disarticulation. Historically, for those people with injuries above the elbow, recovering function has been a greater challenge than for those with injuries below the elbow. This is because the nerve signals traveling to the missing limb after amputation cannot even be detected by conventional myoelectrical devices.

RoboticArmWEB

The new surgical procedure Hopkins offers, and its accompanying prosthetic technology, has become a reality more rapidly than it was imagined even a year or two ago. It was projected for perhaps 2016. Back in 2006, The Defense Advanced Research Projects Agency, DARPA, launched the Revolutionizing Prosthetics program with two objectives to improve upper limb prosthetics. Until this point lower limb prosthetics were advancing well. But upper limb prosthetics required a more technologically sophisticated approach, less mechanical and more capable of accessing cortical signals. DARPA suggested two challenged to be solved. One strategy for patients with high level nerve damage offering direct brain control. And another option for those with above the elbow amputees for surface control by targeting motor signals. The engineers and surgeons at the Johns Hopkins Applied Physics Laboratories took up this challenge and made both strategies real.

Targeted Motor Signals

My call to Dr. Chi was to understand this second strategy: accessing motor signals. With this strategy it is now possible for patients to control an artificial limb with their own thoughts: thoughts originating in the cerebral cortex. And while the areas supplying motor impulses from the cerebral cortex are often highly degraded in the months following injury, the Johns Hopkins experts are finding that these cortical areas are remarkably plastic and offer great potential for rebuilding those neural signals. Cortical signals passed through peripheral motor nerves, they are adjusted with surgery, and they are targeted so their impulses are picked up by EMG electrodes outside the body, in the socket of the prosthesis.

Speaking with Dr. Chi, and later, Dr. Francesco V. Tenore, Project Manager at Biological Sciences and Engineering Group, Johns Hopkins Applied Physics Laboratory, I was curious to learn how the signals from the brain actually translate to a movement in this futuristic-looking robotic limb I’d seen in photo images.

IllustrMaaskeWEB

Step 1: Channeling the Whole Signal

Targeted muscle reinnervation surgery is where the revolutionary solution begins.  Dr. Todd Kuiken first proposed the idea of the surgery, working at the Rehabilitation Institute of ChicagoCenter for Bionic Medicine. Now Dr. Chi is one of a few surgeons in the country performing this technique. Targeted muscle reinnervation is a procedure which reassigns nerves to residual muscles that are still intact. Dr. Chi finds and tests for viability of the available nerve endings that remain in amputated muscle tissue. Then he does a coaptation of the neural wiring which will allow the nerve signals to rerouted. If necessary, larger nerve trunks are cut and reassigned to underutilized muscles which will be better able to transmit this neural signal at skin sites around the amputation. The larger the signaling from the originating tissue, the more viable and rich the output signal will be available. After the surgery and with the fitting of the prosthetic, these signals will then be detected at the input region of the modular prosthesis and translated to output EMG electrodes.

There are no electrodes placed in the tissues of the body or under the skin. There are no foreign materials placed in the body at all during Dr. Chi’s procedure. All the electrical and processing components have been fitted to the modular prosthetic itself. What he’s creating offers a noninvasive method for advanced control of myoelectric devices: the robotic arm.

Step 2: Amplifying the Nerve Impulse

The sensory nerves in the skin of a patient who has experienced amputation will retain their “knowledge” or “awareness” of the region they originally offered sensory information through. Let’s say you touch a particular and consistent place on the amputated trunk of a person who has lost their limb. When you touch there, the patient will perceive that touch as occurring in the region that the nerve originally targeted, such as the tip of the pinky finger, or, the palm-side of the lower thumb. Peripheral nerve awareness by these higher-level nerves create a map of the missing limb. This mapping is felt by the patient and often referred to as a phantom limb. As Dr. Chi says, “Our patient can perceive up to 90% of the sensory awareness being returned to his skin via the prosthetic.” That’s an remarkable retention of the distal awareness a nerve can carry. It means that sensors in the prosthetic can send signals to vibratory tactors in the socket of the prosthesis, so that patients will actually perceive their fingers, their artificial fingers, as feeling touch. This capability is still in its early stages. Stimulation is being offered from the thumb and the pinkly of the prosthetic. And two kinds of touch can be picked up: hard and soft objects. In total, then there are four sensory inputs available to patients presently, in this early stage of the technology. As the surgery advances, there is every reason to believe that more inputs will become possible.

HandOnTableWEB

Researchers like Dr. Francesco V. Tenore, current Project Manager at the Biological Sciences and Engineering Group, use this sensory awareness to enhance the digital algorithms. Signals are detected by EMG electrodes from the muscles on the surface of the skin around those muscles. The nerve signals are collected by electrodes in the socket of the modular prosthetic. Algorithms, designed and refined by engineers, are integrated with the processor. The processor, nested in the palm of the prosthetic hand, integrates these algorithms, decodes the nerve signals emerging from the muscle to the skin, and produces a control signal to actuate the appropriate region of the prosthetic hand. The signal being produced here is adjusted, continually as necessary, based on each patient’s functional needs. That output signal is refined based on how that patient’s cortex and muscles are learning to respond and feed signals to and from the prosthetic.

As Dr. Chi stated, “Just 15 years ago algorithms for this amplification would need to run the code for 24 hours.” That’s how long it would take the signal to process input and send it to the computing device. So much has changed since then.

Capability this sophisticated is made possible by many contributors over time. Dr. Chi offered credit to many researchers who came before him. One is Colonel Geoffrey Ling, Defense Advanced Research Projects Agency (DARPA), who led the project for Revolutionizing Prosthesis (RP) at Johns Hopkins. He was the first to bridge the gap between the viable tissue in a patient’s arm and the modular prosthetic limb. He conceived and developed a device that can be replaced to every level, with sensors feedback pressure and temperature.

Step 3: Processing of the signal to the Myoelectrical Device

Signals sent to the socket of a modular prosthetic are collected by at least 8 electromyography (EMG) electrodes and then relayed to a processor in the palm of the hand of the modular prosthetic device. Processing is handled by algorithms available in a commercially available and customizable processor. The patterns and algorithms are established and modified by computer input, and adjusted with time for each individual patient’s changing needs. Signals generated are not only different between people, but may be different in different sessions with the same patient.

What’s even more amazing is that with greater practice and customized modulation of the signal impulses, patients and the modular prosthetic “learn” to work well together. Input loops and feedback loops work together. The algorithms are studied by scientists at Hopkins, so that delicate signals from the viable muscle in patients can be transferred to an accurate reading of the user’s thoughts. When this nerve ending stimulates the innervated muscle and the muscle signal is collected by the EMG electrode, then the algorithm decodes the patient’s intent by executing the desired action through the modular prosthesis. And, as Dr. Chi says, “Because of increasingly sophisticated computer-generated algorithms, we’ve had constant modification and upgrading of these algorithms.”

As physical therapy accelerates the recovery of a patient’s mobility, feedback from therapists provides guidance for the continued adjustment of the algorithms that allow a patient to more effectively utilize their prosthetic.

What Next?

Tremendous collaboration among experts in the medical, scientific, and engineering community led to these cutting-edge technologies now available for brain and muscle control of the modular prosthetic. Dr. Chi expects that in the future he will be conducting smaller and smaller nerve branch divisions, to be divided from large bundles. He expects a greater capability to route and reroute surrogate sensory areas. This will offer more sophisticated targeting of those nerve ends. Naturally, he expects the algorithms to become more sophisticated with feedforward and feedback loops. He expects more isolated and sensory feedback to be harnessed. Dr. Chi hopes for improvements that will prevent neuromas and to regenerate the nerves themselves. “We still don’t have great methods for regenerating nerves that are already damaged,” Dr. Chi reminds.

A Note to Every Physician

Dr. Chi emphasizes that no patient should now be overlooked. No matter how high the level of amputation above the elbow, and no matter what the cause of the limited limb function, no patient should be excluded from the possibility of a functioning modular prosthetic. Physicians who are aware of potential candidate patients can contact the Johns Hopkins research center.

Albert Chi, MD
Assistant Professor of Surgery
443-287-0618
achi3@jhmi.edu

By Laura Maaske, October 1, 2013
Medimagery Medical Illustration & Design
info@medimagery.com
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– See more at: http://medmonthly.com/features/reality-mind-controlled-limbs/#sthash.9xsKtnj7.dpuf

ModularProsthetic

My most popular medical illustration


atherosclerosis(1000)

Recently I have been reworking this image. Over time, this is my most asked-about illustration.

Atherosclerosis is a vascular destructive condition of the blood vessel so that the wall of an artery holds an accumulation of a cholesterol-based materials. “Arthero” refers to the artery. “-sclerosis” means hardening or loss of elasticity of a blood vessel.
This is a digital illustration created as part of a traditional flipbook. It has been purchased and copyrighted by Merck Pharmaceutical, 2000. Medical illustration prepared by Laura Maaske – Medimagery LLC

Laura Maaske, B.Sc., M.Sc.BMC

 
Laura Maaske, October 4,, 2013
Medimagery Medical Illustration & Design
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