All posts by erin

Prosthetic Devices: The Mystery of Human Design

BioTechnology

In the course of an average day I go up and down the stairs in my apartment building, I walk to class, and I run errands – all on foot. Not having a car, or even a bike drives home just how much I rely on my legs to get me where I need to go. But what would I do, if simply getting up in the morning and walking to my destination wasn’t possible?

For millions of people in the world, it isn’t. When people say that we should appreciate our health, I think of viruses, cancer, heart disease, or mental illness – I rarely think of the fact that I have all of the parts of my body that I’m supposed to have. For those individuals who don’t have their legs either by a birth defect, traumatic accident or as a result of war, the loss of mobility changes everything about how you would go through your day.



via Wikimedia Commons

The leg, knee, ankle, and foot (the lower extremity) perform two biological functions – stability and mobility. The lower extremity is designed to hold the body’s weight. According to Dr. Mark Geil, Director of the biomechanics laboratory in the department of kinesiology and health at Georgia State University, the lower extremity is amazing in its ability to support the body given our height and the relatively small surface area provided by the foot. In addition to stability, the muscles in the leg are key to making us mobile at various speeds, and over a variety of terrains and conditions.

For people who don’t have or have lost their leg, replicating the stability and mobility of the natural leg is the challenge presented to the researchers who design prosthetic devices. Prosthetics are artificial legs made of metal and plastic that take the place of the lost limb. But what mechanical challenges does replicating the human body entail?

The process of creating an artificial limb that acts like a human leg is called biomimetic design. According to Dr. Geil, just the act of walking can be incredibly complex, so researchers study it to inform their designs. In some cases, the goal is not to get the artificial leg as anatomically similar to a real leg as possible – it is to get the functionality as similar as possible.

Dr. Geil gives the example of a foot, which uses controlled motion through eccentric action of a muscle, called the tibialis anterior, to absorb shock every time we take a step. A prosthetic foot/ankle unit has no muscles, so the function of shock absorption has to be replicated through materials built into the artificial foot that essentially has a solid, immobile ankle.

But are there elements of human design that cannot be replicated by the ingenuity, creativity, and dedication of researchers? The answer is quite simply, yes – muscles.

“Muscles are the only tissue that can actively produce force,” says Geil. “They are not just springs that can store energy and return it, they actively produce energy. There are a few powered prosthetic components available now, and they generate force, but they must do so via a heavy motor and batteries. Nothing comes close to the elegance and efficiency of muscle action.”

via US Army Flickr

According to Dr. Geil, replicating human anatomy and function is the “Holy Grail” for biomimetic design. But finding a way around the problem posed by muscles is only part of the problem. The human leg is designed to accomplish a vast array of activities – and this diversity has proved difficult to make possible with a single prosthetic leg.

“We think nothing of ascending and descending stairs, walking slowly or quickly and sometimes running, stopping, turning, sitting and standing. We walk on varied surfaces and up and down ramps. We climb ladders or kneel,” says Geil. “I believe that something we’re still missing, and something that might be designed into future prosthetics, is the adaptability required for different conditions and tasks.”

While the technology needed to give people who have lost a limb a prosthetic that can do all the things that a natural leg would be able to do isn’t available yet, there is progress being made to understand the way the human body works. The more researchers know about the body – the better they will be at making machines the act like the human body.

For all of human history we have been studying ourselves, trying to figure out how these bodies work – and there is still so much to know. The next time I take the stairs in my apartment building, and walk the few blocks to campus, I know I’ll have a new appreciation for the legs that are getting me there. Not just because I have them, when so many others don’t, but because I appreciate how beautifully, and still mysteriously, they are designed.

Synchrotron: The End of an Era?

Grad School, Guest Lecture, Research Funding, Science History,

I’ve said before that being back on a college campus offers so many unique opportunities. This week was no exception with the visit of Bill Blakemore, ABC News climate change correspondent, AND a trip to UW’s Synchrotron Radiation Center. I got several opportunities to talk to Blakemore, and I highly suggest checking out his show Nature’s Edge – but rather than delve into climate communication (a topic on which I could spew my opinions for hours) I want to focus on the SRC.

Today, my internal dialogue was triggered by the trip I took with my colleagues from the School of Journalism and Mass Communications, through the cows and the nothing, to tour the SRC. Located about 30 minutes from campus, the SRC is a particle accelerator that is used by hundreds of researchers each year. Now, I make no bones about the fact that I am scared of physics – but even I was able to understand and enjoy learning about what the SRC does.Whenever I leave downtown Madison, I go through the same internal dialogue: “There are cows. Where am I? I don’t belong here. There are cows. And nothing. As far as I can see. Cows and nothing. What am I doing in Wisconsin?” I hate to admit it, but I do still suffer from re-locaters remorse. I don’t dislike Madison, but seeing prairie or open fields for miles so close to town still shocks me every time.

The “radiation’ part of the name Synchrotron Radiation Center has nothing to do with nuclear radiation, what we have all been worrying about with the Japanese earthquake. Rather, radiation refers simply to the center’s main purpose – to create light for scientific experiments. If you think back to what you know about the electromagnetic spectrum, you’ll remember that there are different forms of light – visible light, microwaves, radiowaves, uv rays, x-rays, etc.

The SRC conducts a variety of experiments using the different forms of light (infrared to x-ray range) that are generated by accelerating electrons around the Aladdin storage ring. I am not going to do a better job of explaining how the ring works than the SRC does on their website, but I will say that the wave of light created by winging the electrons around needs to be contained/controlled and that is essentially what Aladdin does. It is the mechanism that harnesses the light so it can be used in experiments.

The center was opened in 1981, and has a special role as far as SRC’s go because the UW center gives visiting researchers 2-3 weeks to work on their projects, unlike the 3-4 days they might get to conduct research at another facility. Because the SRC is funded by the National Science Foundation, researchers don’t have to pay to use it – it is free. Free resources, that invest significant time in research projects, are rare these days.

They are about to become even rarer. The SRC at UW has not made it into the NSF’s new budget, which means that funding (the approximately $5 million it takes to run the center) will be cut off in August 2011. I appreciate that the SRC isn’t cutting edge. It isn’t shiny and flashy, but it still has scientific merit. The idea of the resource going dark seems like such an utter waste.

My colleague Eric, who works in outreach at the SRC and organized the JSchool’s visit, has a terrific post on his blog about the closing of the SRC and the closing of Chicago’s Fermilab – which will leave a hole in the scientific research community in the Midwest. I encourage those of you in Madison to take the time to check out the SRC before the last electron goes shooting through the Aladdin ring, and for those of you not in Madison take a look at the federal science foundation budgets – is there a resource near you that will be lost in 2011?

The reason I chose to focus this post on the SRC rather than Blakemore’s visit, is because the SRC is such a uniquely Madison, WI experience. It reminds me of why, in spite of the cows and the nothing, I came to Madison. This is the site of some extraordinary scientific research – discoveries that I find fascinating, that ignite the sense of awe and wonder about the world that I have tried so hard to cling to as I have transitioned into adulthood. Seeing the SRC’s inquiries end, while sad, makes me appreciate that I was in Madison in time to experience it for myself.

Science For Six-Year-Olds: Giant Earthworms

Environment, My Personal Life, Science For Six Year Olds

This is my third post for Mrs. Podolak’s first grade class at Lincoln-Hubbard Elementary School. We have been talking about animal behavior with Alex the Genius Parrot and Animals who use tools, but now to kick off the first grader’s new science unit, we are going to talk about worms.
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When it comes to worms, there is no specimen more impressive than the Giant Gippsland Earthworm. Check out this video to learn more about this massive worm:

Giant Gippsland Earthworms are gross yet fascinating, but these worms are found in Australia. What about the worms in your own backyard? They might not be giants, but the common earthworm are still pretty impressive little animals.

 

The common earthworm (Lumbricus terrestris,) also called a night crawler, is found throughout North America and Europe. Compared to the Giant Gippsland Earthworm which is usually about 20cm long, the common earthworm is usually just 7-8cm long.

The earthworm has a mouth and a butt (anus). It also has a brain, a nerve cord (the way humans have a spinal cord,) a heart, and a digestive system. So we know what worms look like: they can be big or small, and they are made up of several different parts. But what do earthworms do? Earthworms are experts about dirt. They tunnel through soil making pockets of air and water which are important for plants and the microorganisms that live in the soil.

To help learn more about worms check out these Frequently Asked Questions posed by students just like you! As always, feel free to ask me questions, and I’ll get back to you as soon as I can. Good luck on your new science unit, and learning all about earthworms!

Hal Herzog, Animal Ethics & the Alien Problem

Book Review, Good Writing, Grad School, Public Perceptions, Zoology,

Last semester I read many more books (thus I did a lot more book reviews) than this semester which has mostly been devoted to academic research papers. But I do have two books that need reading for my zoology class on human and animal behavior with Patricia McConnell.

Some-We-Love-Some-We-Hate-Some-We-Eat-Herzog-Hal-9780061730863I finally finished the first of the two assigned books, Hal Herzog’s Some We Love, Some We Hate, Some We Eat – Why It’s So Hard to Think Straight About Animals. I’ve been reading Herzog’s book all semester, so my evaluation of it draws on a slightly disjointed memory but I think I can summarize his main point with two statements:

1. Most people choose not to (or don’t know enough to) think about their personal moral philosophy. Not thinking about how we feel about animals is what allows us to love puppies so much while we happily chow down on a Big Mac.
2. Those people who have spent a tremendous amount of time trying to discern their personal moral philosophy about animals either A. remain horribly conflicted or B. Choose a philosophy with regards to the treatment of animals that societal pressures make very difficult to implement (for example, all creatures are equal – if you save an iguana from a burning building instead of a human baby, society is not going to look kindly upon you regardless of your belief that the iguana and the baby are equals)

Herzog’s answer to his main question “why is it so hard to think straight about animals?” largely comes down to because you’re damned if you do and you’re damned if you don’t.

The book tries hard to cover a variety of topics that impact the way we feel about animals, some obvious (factory farming, animals in research, hunting) and some less so (cockfights, dog shows, gender roles.) I don’t intend to go into his arguments for and against certain behaviors, but to give an example of the kind of analysis he provides I will share the anecdote from his chapter “The moral status of mice,” on the use of animals for biological research.

Herzog frames animal research this way: Think of Steven Spielberg’s 1982 classic film ET. Remember how close Elliott and ET became, and how heart wrenching it was to see ET go back to his home planet? Well, what if there was a disease destroying the alien’s on ET’s home planet, and the reason he really came to earth was to scout out organisms of lesser intelligence to test possible remedies on. Elliott’s intelligence was far less than ET’s. So how would you feel if at the end of the movie, ET kidnapped Elliott and took him back to his home planet to live the rest of his life as the subject of research. It would save millions of aliens. But ET still essentially destroys Elliott’s life. Not really a satisfactory ending, I’d say.

So if we don’t want ET to kidnap Elliot just because he is of lesser intelligence, then what do we do when humans are like ET and mice are like Elliot? Should we experiment on mice just because they are of lesser intelligence? Previous logic would lead us to say no, we should not experiment on the mice. But yet, I’m still in favor of animal research. Philosophically, I shouldn’t be. But there is something about experimenting on a member of my own species that I find morally reprehensible. It is the reason we don’t conduct experiments on people in coma’s or with mental retardation. But if you are always putting humans first, how can you still treat animals with respect and moral standing?

I’m not here to answer the questions thinking critically about animals pose. Herzog has 280 pages of highly intelligent, moving, and entertaining explanation, and he still doesn’t answer most of them. But he will get you thinking about your own behavior, why some animals matter to us more than others, and why humans think the way we do.

It is important for everyone: meat eaters, vegetarians, pet lovers, people who avoid animals, etc. to think about why they feel the way they do about animals. I was surprised by the conflicts in my own way of thinking, and sadly I now fall into column A – thinking critically, but still horribly confused. At least I’m thinking right?

Robots on the Front Line

Grad School, Headline Makers, Technology

I’m working on an article about how robots can and more importantly, can not, be designed and programmed to function like humans. In anticipation of this, I’ve noticed that this week robots have been making headlines for their role in the war in Afghanistan. But while useful, robots are no replacement for the ingenuity, decision making, and critical thinking capabilities of real, human soldiers.
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If the war in Afghanistan was fought with light sabers, aliens, and Samuel L. Jackson I think the conflict would be over by now. But alas, the light sabers, aliens and Jedi warriors of Star Wars are figments of a time long long ago in a galaxy far far away. But what about the battle droids seen in the video? A robot war sounds like something you could only see on the silver screen, but new technology being implemented in the Afghan war may be the FIRST STEP (note: ONLY a first step) toward a real conflict that is decided by robotic prowess.
According to U.S. Marine Corps. Lt. Col. Dave Thompson, project manager for the joint project office for robotic systems (hows that for an example of a ridiculous round-about government-given title,) there are more than 2,000 ground robots assisting U.S. troops in the war in Afghanistan. But, while it might be fun to evoke the imagery of the battle droid, engaged in an epic fight, REAL robots serve a very different function.
When we talk about the United States’ “robot ground troops” we are essentially talking about computers that can identify bombs and other dangers. The robots do this in one of two ways A: with a combination of sensors and imaging equipment that relays to the human troops that there is a bomb present , or B: by going into an area ahead of the human troops, so that if there is an explosion, the robot takes the hit instead of the humans. 
Robots are NOT running around in the desert wielding AK-47’s, taking out the Taliban. Let me say that again, robots are NOT actively engaged in battle. They do not fight, at least not in the Star Wars battle droid sense. Instead, America’s robot troops are just another tool in the technological arsenal that the U.S. uses to bolster the abilities of its human troops. 
Much of America’s security and defense technology is classified, so we don’t know EXACTLY what it is used for and how these robots accomplish their tasks. But we do know that they are successful enough for ground troops to be requesting the implementation of more robots. We also have access to some information about the use of robots in war-zones like the iRobot (yes, the makers of the Roomba vacuum) line of products. 
So while the battle droid only exists in a galaxy far far away, that’s not to say that the robots in Afghanistan are not supremely cool and impressive. Take a look at this CNN report on the iRobot technology to see for yourself what our robot troops can do: