Dun dun dun...

Hello Readers!

It's time we cover that daunting, merciless, and most unnerving topic. If you haven't guessed it yet, we're talking about engineering. But don't fret! I'll keep this simple (as far as simplicity goes) and to the point. Please refer to the picture of the BiOM below, the diagram which describe its components and the human ankle-foot system.

BiOM

BiOM Components

Human Foot + Muscles

In the second picture on the diagram, we have the following: the motor spins the wheel closest to the right, which is hooked to a belt. This spinning, forces a motion in the belt, which, in turn, spins the left wheel. This left wheel is attached to a screw (the ball screw), this spinning then pushes downward on the heel, which pushes the series spring. But to counteract this motion, there is pull upwards on the parallel spring. This push and pull motion is to prevent the device from slamming down--it allows for more control. For example, when we walk, each push downward is managed and controlled, instead of slammed down. This is done by our body's force on the heel and the muscles at the front of our leg pulling up at the same time. The BiOM solves for this with a push on the series spring and a pull on the parallel spring. 

I hope I made this as logical as one can make the inner mechanism of a motorized prosthetic device for you all! 

Until next time, 

Pooja

Iron Man's Delivery

Readers!

It's official, I am in love with Iron Man. After years of watching the movies where a sassy Robert Downey Jr. helps/saves/and makes a mess out of the world, he's done it for real, well, he's done some of it for real. Almost 12 days ago, Tony Stark, as in the Tony Stark of Stark Industries presented 7-year old Alex with a 3D-printed Bionic arm.

Holy crap!

Working with Albert Manero and Limbitless Solutions, RDJ presented this 7-year old, who was born with a right arm deformity, a working, prosthetic arm. Not only did the team bring a wild smile to Alex's face when he met Iron Man but they did so for only $350. Normally, these "robotic technologies" cost around $40,000. The team, though, in fact, donated the arm to Alex after pooling together their "coffee money" and saying "we were all bound to the belief that no one should profit from a child in need of an arm." This wonder was put together by The Collective Project, a team trying to empower great ideas. To learn more about the entire presentation, go here.

Alex's Arm 

Though not a device for transtibial lower limb amputees, this and the ankle-foot device I work with are both targeted to achieve one very simple goal: helping people around the world. 

"You know, it's time like these when I realize what a superhero I am"

                            -Tony Stark 

Prostheses: A History

Hello World!

I'm back and without any real project updates. Because subjects keep rescheduling with the NAU team, I'm still unable to start gathering data. So today I will give you a history of prosthetic devices. It may not seem so fun, but just wait.

Prosthetics go way back, farther than I had even imagined. In fact, in the time of the Punic Wars it's said that a Roman general lost his arm and had an iron one fashioned for himself to continue fighting. If you don't know the exact time period of the Punic Wars (which I don't expect you to), it's 264 BC-146 BC.

Advance a few (thousand) years and researchers have located what they believe to be the first preserved artificial body part--a mummified prosthetic toe made from wood and leather. The toe belonged to an Egyptian noblewoman who's been preserved for nearly 3,000 years! Sure, wood and leather don't compare to a motor and cast, but they lay a groundwork for years of prosthetics ahead.

The toe!

Post mummified Egyptians, we see major advances in prosthetics in 16th century France. In fact, the advancements made during this time are still widely used in the prosthetics today. Military doctor, Ambroise Paré, developed hinging hands and legs that could lock at the knee alongside harness attachments. After his work, a Dutch surgeon, Pieter Verduyn, developed a lower leg prosthesis with specialized hinges.

By 1812, a prosthetic arm was developed which could be controlled by the opposite shoulder through multiple different straps. Later in the 1800s, the creation of gaseous anesthesia allowed for more precise and careful surgeries. Additionally, due to better and more hygienic conditions, surgeries had a much higher success rate, which in turn, increased demand for prostheses. This demand continued to increase into the 20th century for various reasons (like WWII) until the National Academy of Sciences developed the Artificial Limb Program in 1945.

The shoulder-arm attachment

Give it 70 years and we're at modern day prosthetics. Which have become wildly more advanced. In an article from Gear Patrol, Amos Kwon and Ben Bowers explain these advancements through one man's story, and no, it's not the already mass publicized story of Oscar Pistorious, "In the case of Sergeant 1st Class Leroy Petry, recipient of the Congressional Medal of Honor, a biomechanical hand allowed him to rejoin the Army Rangers. Sensors in the prosthetic forearm and hand pick up electro-muscular signals which would normally cue his own hand to move, giving him an intermediate level of dexterity that mimics basic hand movements."

Leroy Petry and his bionic hand!

I hope you found this history as interesting as I did.
Until next time,
Pooja

Week Four

Welcome back!

In the past week, I haven't had much experience with walking or the BiOM, sadly. My week was instead riddled with House Of Cards and popcorn. Though, I do have some good news-- I was officially granted IRB (Institutional Review Board) approval to work with human subjects! Testing hasn't begun quite yet due to rescheduling conflicts but by May 18th I will have a full set of crunched numbers ready to present. Prior to testing, I will continue reading, reading and... reading.

Some of the reading I've already done, includes this article, which expands bionic technology beyond the scope of the prosthetic devices. It considers everything from text messaging to sensory feeling in synthetic limbs. Not only did reading this allow me to better understand the background of prostheses but it gave me better perspective on these developing technologies and how they influence everything around us. Development in these fields doesn't only indicate hope for enhanced walking (amputee or not) but it shows hope for enhanced communication or even military infrastructure. In fact, the Department of Defense has funded a project which develops a device to be worn in unison with fully functional limbs to give soldiers a faster running speed--the four minute mile.

Anyway, I hope you enjoy the article and are also able to consider the widely received benefits from this developing industry. Hopefully, by my next post I will be able to tell you how my first day of testing has gone.

"I cannot abide falling back to square one"
                      --Frank Underwood

Week Three

Hello Readers!

I post this with exciting news--I have found four of my own "subjects" to walk backwards for me so I can develop a better understanding of backwards walking! Today, I will show you how these human steps work in a more specific sense than "step back, step forward". My four walkers, S1, S2, S3, and S4 are all incredibly athletic and have had zero past issues with any lower limbs. They also didn't know for what reason they were being asked to walk backwards, so as to eliminate any strange movements they may have had otherwise. Here, I will show you the pictures of one walker with descriptions of each movement.

1. This is the first initial step back. Here, the subject's left foot is stationary while the right one lifts up before moving back, this is called controlled dorsiflexion.

2. Following the previous step, the subject has moved her right foot back and touched her toes down to the ground before setting her entire foot flat. This step is called controlled plantar-flexion. Controlled, in this context, means that the walker is able to control their foot's movement, so instead of the foot slamming onto the ground, it is controlled and moved carefully down. Often, people with walking disabilities don't have this control, which is why you see their steps as heavy and slammed.

3. Next, as the right foot touches down, her left foot begins to move upward with her heel as the "pivot point", which develops a torque. This is where we see physical properties being able to relate to a biologically inspired prosthesis. Again, this movement is called dorsiflexion.

4. Finally, the step is finished when the subject brings her left foot back and touches her toe to the ground. This movement is called controlled plantar-flexion.

In each of these moments, we see that most of the muscles tensed are in her calf muscles and quadriceps rather than the muscles of the ankle, which are only tensed when the subject is raising or lowering her foot, dorsiflexion and plantar-flexion, respectively. Whereas, in forwards walking, the calves and quads are much less often tensed. This difference in movement between backward walking and forward walking is one reason it's important to test for backward walking.

My apologies if this post makes you pay a little too much attention to how you walk. After starting this project, I find myself quite often noticing the gait of those around me.

Until next time,
Pooja

Week Two

Hi Readers!

I am pleased to announce that I got to interact and use the BiOM last Monday. Prior to going to the lab, I didn't know what to expect. I didn't know whether I'd receive an in-depth lecture on a biologically backed BiOM or a lesson on power efficiency. But, unsurprisingly, I ended up getting the best of both worlds and a BiOM tutorial. Having two advisors from different fields (Biology and Engineering) was incredibly beneficial in learning about the device.

Here's some of what I've learned so far:

1. Currently, there's a muscle model referred to as the Hill Model. This model was primarily used as a design for understanding muscle tension, force and velocity. When testing the BiOM, the team at NAU uses a different model, their algorithm, to better relate the device to its biological backing. 
2. This device relies on a biologically inspired algorithm that is meant to meet necessary physical conditions like power efficiency.
3. Not only is the BiOM powering any movement but it does so accordingly to its users specific weight and height. 
4. The BiOM has been tested by many researchers, all which conclude that it conserves more energy than a passive prosthesis and uses nearly the same amount of energy that's used by a non-amputee. 
5. The testing at NAU has already shown significant data in stair ascent and forward walking. Specifically, the data indicate the powered device is more efficient than passive devices. Additionally, subjects have been generally more pleased by using the BiOM. Problems with backward walking come from the device being less efficient than the human ankle.  

Next week, I'm having a few random friends walk backwards for me so I can see exactly how the leg moves in comparison to how the BiOM moves. 

Thanks for reading, 

Pooja 

Week One

Hi Readers,

Well, my first week of learning has passed. And here's the one thing I know: my reading, researching and learning is nowhere near over. While I do know a little more about muscle functions, there's still plenty to review and learn before I'm able to apply my new knowledge to the prosthesis. Because the device mocks muscle movement, and I'm researching on the biological side of my project for now, I need to first understand how the muscles of our lower limbs work. So, while I delve deep into an anatomy textbook, I hope this article describing the prosthesis' ingenuity helps develop your understanding.

Next week, I will have my first exposure to the engineering side of my project! Meaning... I finally get one step closer to touching, testing and looking wonderstruck in the face of the newly reconditioned BiOM!

With much anticipation,
Pooja