Clarkesworld Magazine Issue 92 Page 10

  The next step in control mechanisms involves myoelectrics. A myoelectric system gives the wearer direct control over some of the prosthesis’ movements, the degree of which largely depends on the tissue and muscle left in the residual limb. Those muscles still receive signals from the brain when a command to move the limb is issued, even though the limb is no longer there. Normally, those nerve signals dead-end, but myoelectric sensors pick up those signals and interpret them into controlled movements of a prosthetic limb. In some cases, nerves are surgically rerouted to send signals to different existing muscles.

  To use a myoelectric limb, the wearer has to undergo some training, and the device must be adjusted until they “learn” how to work together. By tensing specific muscles, the wearer can induce specific movements in the prosthetic. Different intensities of the same muscle can create different movements. These commands can be built up into very complex movements, including sequential finger movements or large shoulder motions. Even in cases where nerve damage or a lack of sufficient remaining muscle in the residual limb would prevent myoelectric operation, muscles in the chest and back can be used instead.

  Myoelectric arms and hands are already on the market. The bebionic3 hand and a number of elbow, wrist and hand mechanisms from Ottobock are just a few examples. Myoelectric legs provide even greater freedom of movement compared to a dynamic leg like the Rheo Knee, because the wearer can activate motors to lift the leg up stairs or even adjust it while sitting without manually moving the leg by hand.

  The concept of myoelectrics ultimately leads to brain-computer interfaces. If the control system for our muscles is really just a network of signals and relays, why not cut out the relays and go directly to the command center? This may be necessary because a spinal injury prevents any nerve signals from moving through the body, making myoelectric control impossible.

  Whenever something happens in your brain, whether you’re reflecting on a memory or deciding to make a fist, electric signals are generated as the ions in each neuron create a difference in electrical potential. These signals can be read either by electrodes inserted surgically into the brain or by electrodes attached to the scalp. There are problems with both methods. The signals are quite tiny, and your skull is a pretty good insulator, so scalp electrodes can pick up crosstalk or just have a hard time getting a reading.

  Implanted electrodes get better signals, but of course they require invasive surgery. They need to be placed in the correct place within the brain to read the signals necessary to control a device. Unfortunately your brain is not an unchanging thing—over time it grows and shifts so that the implanted electrodes slowly migrate away from where they need to be.

  While controlling prosthesis with the mind is an enticing idea, and one with enormous potential, there are a lot of difficulties with brain-computer interfaces. We’re probably a few decades away from the kind of smoothly responsive, accurate and effective control you might see in a science-fiction story.

  Sensory Feedback

  Controlling a prosthetic limb has been a one-way street for many years. The wearer issues a command, the limb receives the signal and performs the task. Only recently has progress been made to send signals the other way, giving the prosthesis a sense of touch. This would allow the wearer to experience someone holding his or her hand, or more easily accomplish tasks like reaching into a bag to grab an apple instead of a pencil. It’s also very important for fine tasks like holding a delicate object. Research in this area is not as well developed as controlling a limb, but DARPA’s FINE (flat interface nerve electrode) already shows a great deal of promise.

  Open Source

  There are three primary reasons for the rapid advance of prosthetic technology in recent years. Increased availability and expertise in working with carbon fiber, along with improvements in carbon fiber manufacturing that make it easier and less expensive to work with, have had a huge impact. Another major factor is DARPA (Defense Advanced Research Projects Agency) initiated their Revolutionizing Prosthetics program in 2006, spurred in large part by the large number of soldiers returning from Middle Eastern conflicts with amputation injuries. Research backed by DARPA support and funding produced several commercially viable prosthetic systems, and major advances in brain control.

  The third factor might be the most exciting—open source prosthetics. Prosthetic wearers have always tinkered with and improved on their limbs, of course, but there was never a method of easily sharing what they’d learned or made, and no framework for working on projects together. The open source concept, in which designs are shared freely with the public so they can be used, adapted, and improved upon, has pushed prosthetic design in new directions and helped push down prices.

  A quick look around the various community projects ongoing at The Open Prosthetics Project shows an astonishing array of development. One group found that plastic zip ties make excellent artificial tendons. Another is using Lego building blocks to prototype hand designs. A project to improve attachment methods (called “suspensions”) hit upon the idea of the Chinese finger puzzle: a sleeve open at each end that grabs onto a finger (or, for instance, an arm stump) with greater strength the harder it’s pulled due to the alignment of fibers within the sleeve. Their early experiments have been promising. Yet another group found a few versions of a classic “split hook” artificial hand that is no longer produced. They hope to reverse engineer it and make new, cheaper versions with modern materials.

  If the progress of prosthetics follows a predictable arc, we’ll see artificial limbs get lighter and stronger in the coming years, as control methods become more reliable and sensory feedback more lifelike. But the most important advance might be making quality prosthetics less expensive. An advanced prosthetic leg or arm can cost tens of thousands of dollars, and few insurance policies will cover the price.

  Open source holds a lot of promise. However, advanced prosthetics will remain out of financial reach for most of the people with amputation injuries or congenital limb problems. There are several charity and outreach organizations, including the Limbs for Life Foundation and the Amputee Coalition. The Open Prosthetics Project even has a wiki page with information on getting financial assistance to buy a prosthetic limb.

  In Kansas City, a young boy with congenital deformity of his right hand couldn’t afford a commercially produced prosthetic. A local teen used shared files by the open source community to create a hand using the local library’s 3D printer, then assembled the hand for the young boy to use. The hand’s designers even adapted the design to fit the boy. It’s certainly a heartwarming story, but it’s also a great example of the benefits of open source prosthetics.

  About the Author

  Ed Grabianowski writes for sites like HowStuffWorks and io9 about science, technology, games, and anything else that looks interesting. His fiction has been published in Black Static and the Geek Love anthology.

  The Immense Costs and a Shred of Optimism:

  A Conversation with L. E. Modesitt, Jr.

  Jeremy L. C. Jones

  Cyador’s Heirs, a novel of five hundred and twelve pages, begins with a boy and a girl sitting in awkward silence. Two guards watch them and two more guards watch those guards. The detail is fine and the prose discreet:

  The boy and the girl sit on a carved wooden bench in the shade beside the small courtyard fountain. He has pale white skin, unruly red hair and a strong straight nose just short of being considered excessive. Her hair is black, as are her eyes, and her skin is smooth, if the light tan of aged parchment. Her name is Kyedra. His is Lerial.

  Kyedra breaks the silence with a question. There is a slight language barrier, and more questions. They discuss differences in their customs and the tensions between their cultures.

  So gently, it begins . . .

  Cyador’s Heirs by L. E. Modesitt, Jr. is the seventeenth novel in The Saga of the Recluce Series but it offers an entry point for newcomers, set as it is, after the fall of Cyador, at a time of re-bu
ilding, at a time when the younger generation must reap the past.

  L. E. Modesitt, Jr. started out with poetry and non-fiction and has been writing fiction since the early 70s. Modesitt has a rich professional history as, among other things, a Navy pilot, a staff director for a U.S. Congressman, and Director of Legislation and Congressional Relations for the U.S. Environmental Protection Agency. His careers in the military and politics serve as distant background sources for his complex novels.

  All in all, Modesitt is the author of more than five dozen fantasy and science fiction novels. His series include The Imager Portfolio, The Corean Chronicles Series, The Ecolitan Matter Series, The Forever Hero Series, The Ghost Books Series, The Saga of Recluce Series, The Spellsong Cycle Series, Timegods’ World Series. His standalone novels include Haze, Empress of Eternity, and last year’s The One-Eyed Man. His novels are long and multi-layered with extensive casts of complex character, yet they remain, line for line, intimate and brightly lit.

  Below, Modesitt and I talk about Cyador’s Heirs, writing, and his work in progress.

  What are some of your favorite moments in Cyador’s Heirs?

  I can’t say that I have favorite parts, per se. What aspect of the book that I like is how much Lerial changes from the beginning to the end without really understanding how much better a person he has become, even as he recognizes the sometimes ruthless imperatives and cruel choices required in good governing.

  Does writing a novel answer or present more questions for you?

  I think it’s more that I’m trying to answer existing questions about life, technology/magic, human nature, society, government in a way that tells a good story and makes sense in life while providing both a sense of the immense costs and a shred of optimism. My characters do generally achieve their goals/dreams, but the costs are far higher than they ever thought possible at the beginning of their journey, and they also learn more than they anticipated, learning that is not always welcome or pleasant.

  Do you ever lose that “shred of optimism?” Are the costs ever too high for you? For your characters?

  I try not to lose that shred of optimism, but I’d have to say that there isn’t much optimism in the ending of In Endless Twilight, the last book of The Forever Hero. And I think that I would personally have great difficulty paying the costs incurred and paid by some of my protagonists.

  Do you approach series novels differently from standalones? Is one easier than the other?

  Every book is a challenge, if in different ways. For my fantasy series books, particularly in starting the first book, I need to do a broad scope of work, dealing with history and background, culture, economics, geography [and yes, maps], the magic system, and societal beliefs. This is critical because readers will question the slightest possibility of inconsistency. In writing a stand-alone, the scope is just as broad, but the depth is less, because I have to convey being part of a larger universe in a less expansive canvas.

  What were some of the challenges specific to writing Cyador’s Heirs? Do you set out to challenge yourself? Do the challenges arise?

  The most specific challenge to writing Cyador’s Heirs lay in the fact that it is a part of the Saga of Recluce, and that the books in the saga span almost two-thousand years. Because I did not write the books in chronological order, by now every reader of the saga knows at least parts of the general history of the world. So each additional volume that fills in blank or fuzzy areas of that history has to be written to be consistent with that history and fit in with all the cultures that have risen and fallen while still presenting an exciting story while revealing and adding yet another intriguing facet in the twisting balance between lands, and between order and chaos.

  I always attempt to do something different with every book I write. That’s one challenge, and in doing that, there are others that inevitably arise.

  In what ways, if any, has your creative process changed in the last forty years?

  When I first started writing prose, I wrote short stories, literally off the top of my head, pretty much start to finish. Needless to say, my sales percentage was less than sterling. When I started to write novels, that didn’t work, and I began to write mosaic fashion, which interestingly enough helped for two reasons. First, it caused me to think out ahead, and, second, it allowed me to avoid getting hung up at any one point. As I’ve become more experienced, I write more than before in a straight line of narrative, but I haven’t abandoned writing sections that will come later in a book. For the last twenty-one years, I’ve been a full-time writer, and that has meant that I devote most of each day to some aspect of writing. The change in the marketplace has meant that I also spend more time on an internet presence and in creating content for my website [lemodesittjr.com] and in doing more marketing in various ways.

  What have been some of your personal landmarks throughout your career?

  In a way, the first landmark was even writing my first SF story. I’d been struggling for over ten years as a poet, getting published only in very small magazines, when someone suggested I write a science fiction story. The second landmark came six years later when Ben Bova, then editor of Analog, rejected a story and told me he wouldn’t buy another until I went and wrote a novel, which was very good advice, given that, so far, I’ve sold every novel I’ve written. The third was writing The Magic of Recluce, which I did as a reaction to existing fantasy books which displayed no understanding of basic human society, economics, technology, or government, and which laid the foundation for my success as a fantasy writer. Others include writing The Soprano Sorceress, my first book from the female point of view, Archform:Beauty, my first book from multiple viewpoints with distinctly different linguistic patterns for each viewpoint; getting a book rejected for a movie by James Cameron because it was “too complex”; making the New York Times bestseller list with books in two different fantasy series.

  Are you having as much fun as it seems like you’re having? And what’re the fun part of writing? The not-so-fun parts?

  For me, writing isn’t “fun.” It is immensely satisfying, especially those moments when I feel that I got something “just right.” But then, I’ve never been a toy-boy or a “fun” type, perhaps because what matters most to me is accomplishment and understanding, and the appreciation and creation of beauty, not only in what I do, but in what others do as well. There’s certainly more of a sense of satisfaction and accomplishment when I’ve finished the final draft and it’s ready to go to the editor than when the book is actually published. The very necessary but not-so-fun parts are going over copyedits and especially first pass galleys.

  Would you be willing to discuss specific novels, stories, or elements in the works of others that you find beautiful?

  I’d rather not, because I can think of quite a number of elements in the works of others that I find beautiful, and limiting myself to what is likely to be printed would single out, unfairly, I believe, those I could mention within the reasonable space and time limitations, and by comparison suggest that those I did not mention were of lesser beauty.

  How do you go about creating characters?

  I have an image of a character early on. That image begins to form when I’m in the process of thinking about the culture, society, climate, and all the other background aspects of the book I’m writing. Part of that comes from my own background. Because it took more than twenty years from the time I sold my first story, and more than thirty from the time my first poem was published, before I was successful enough as a writer to write full-time, I spent almost thirty years in full-time employment doing jobs other than writing fiction, from time in the Navy as an amphibious boat officer to a search and rescue helicopter pilot, a professional economist, and a political staffer in Washington, D.C., not to mention a number of other jobs in which I was far less successful. That kind of experience gives me a lot to draw on, as well as the understanding of the personality traits that make people successful or less so in various fields.

  Ar
e there certain moments in Cyador’s Heirs that are particularly meaningful to you?

  In one part of the book, Lerial makes a miscalculation, understandably enough, given that he’s sixteen and not very experienced in battle, and that miscalculation leads to a death that could have been avoided. The person who died was a relative of a high official . . . and Lerial has to explain in person exactly what happened. That part had a particular meaning to me, which is very personal, given my own experiences as a Navy pilot.

  What are you working on now and how is it challenging you?

  I’m currently working on a comparatively “near-future” [for me, anyway, set a little over a century from now] hard SF novel that’s about as science-intense as anything I’ve ever done. One of the plot points hinges on an extrapolation of a very recent astronomical discovery that hasn’t gotten much press, but what it is . . . well, that will have to wait for when the book comes out, assuming, as always, that Tor decides to publish it.