The 3D custom-fit iUni knee replacement by ConforMIS complements the patient's anatomy.

Like the treads on car tires, the all important cartilage within our knees is slowly wearing down. By the age of 65, in fact, nearly 50 percent of us are likely to suffer from a painful degeneration of this cartilage called osteoarthritis. It’s estimated that one in eight of us will suffer so badly that we will require a partial or full knee replacement via surgery within our lifetimes. As barbaric as it may sound to replace part of your knee with artificial components, a privately-held company named ConforMIS has pioneered a technology to produce custom fit, 3D implants using patient CT scans to resurface bone and minimize the amount of tissue cut out. ConforMIS is trailblazing a revolutionary trend in medicine in which medical devices are tailored precisely to the individual patient, reducing surgery times, speeding up recovery, and improving patient satisfaction. Suddenly becoming cybernetic doesn’t sound so bad.

About half a million knee replacement surgeries are currently conducted in the US every year and that number is expected to rise above three million in the next 15 years. Current implants require a number of cuts to the femur and/or tibia to fit the device. Additionally, many of the products that are currently on the market are off-the-shelf devices that come in a few sizes, so surgeons have to slice off even more bone in order to get them to fit. This can lead to long surgeries and increase the discomfort of recovery as well as the time it takes to get back to normal, usually six to eight weeks. While some knee replacements can last 20 years without noticeable wear, patients that need another replacement may have difficulty because they’ve already had a significant amount of bone removed. This is expected to be a growing problem as the average age that patients are seeking knee replacements is decreasing and people are staying active later in life.

As crowded as this multibillion dollar market is, ConforMIS started up in 2004 to take a fresh approach to knee replacement surgery by custom tailoring surgical tools and implants using patient MRI and CT scans. The result is phenomenal: scans of the patient’s leg are sent to ConforMIS for analysis, and just six weeks later a 3D custom-fit implant is created that precisely fits the patient’s anatomy. A future in which we can trick out our bodies is here. The company’s attitude toward knee surgery is even reflected in their name, where “MIS” is short for “Minimally Invasive Surgery.” Over the past seven years, they’ve garnered $80 million in funding and launched two products for partial knee replacements, the iUni and iDuo, and last month, they received FDA clearance to release their total knee replacement, dubbed the iTotal.

The key to developing patient-specific implants is using personalized imaging data, and toward this end, ConforMIS developed their iFit technology, where the “i” stands for “individualized. This software takes the CT data of the patient’s knee, hip and ankle to create models that account for the unique anatomy of the patient’s entire leg. These models are used to create both the implants and the tools to install them. These tools, called jigs, are the exact same shape as the implants, so they align perfectly to the patient’s knee, but they also have placement and cutting guides that allow the surgeon to make precise cuts to remove minimal amount of bone. With these tools, inserting the implant is a bit like snapping a Lego piece into position exactly where it belongs, resulting in much less manual effort and hence less errors from the surgeon.

Should an orthopedic surgeon determine that a ConforMIS product is a good solution to a patient’s knee problems, they’ll send the patient in to have X-ray tomography of the affected knee. These CT scans are then sent to ConforMIS who manufacture the personalized implants and instrumentation and ship them back to the surgeon when ready. Once the surgeon has installed the implants, the patient goes through all the normal recovery procedures for knee surgery, although surgeons report that with the ConforMIS products, some patients are walking around the next day and are released quickly. Cost-wise, custom-made implants are twice as expensive to manufacture, but ConforMIS does not have to maintain the same massive inventory as competitors, so they can offer the implants at comparable prices to other knee replacement devices.

It’s no surprise that the potential to use this technology in other joints is being developed, as ConforMIS has acquired patents for the hip and ankle as well as the spine. The company values the feedback from surgeons and patients acquired through clinical trials, which has led to the launch of second generation devices last year. Still, they are in an ideal position to provide an increasing number of options for people seeking replacement solutions that are customized to their individual bodies. And who knows what other ways 3D image-to-implant technology is going to transform medicine? We’ve recently reported another success story about a similar custom-fit mesh device designed by an engineer to fit around his own aorta. These stories bode well for the emerging era of personalized medicine, promising a future in which the one-size-fits-all approach to healthcare can be put to rest.

[Sources: Annals of Internal Medicine, CDC, ConforMIS, NEJM, OrthoTec]

As we’ve mentioned earlier, ProDigits is a pretty exciting prosthetic – it shows off some of the leading artificial limb technology around, plus it’s already on the market. The hand can be custom tailored to each particular patient’s disability, as you’ll see in Michael’s case (his thumb fits into the device).

Myoelectric sensors along the forearm measure nerve impulses below the skin, which translates muscle flexing into finger movement. Each digit moves independently, they have pressure sensors to prevent crushing gripped objects, and the device is battery-powered.  How much does all that cost?  Roughly $70,000.

Check out the Today Show feature:

As you can see from the video, ProDigits does involve a learning curve. The prosthetic requires calibration to the individual user’s body, and it takes some practice to master. ProDigits can either be controlled via forearm muscle sensors (as seen in the video) or via remote pressure sensitive pads. Touch Bionics also markets the expensive but impressive i-Limb, one of a number of leading prosthetics that are integrated with the nervous system remotely.

Which is prosthetic?

Michael’s plight with social stigma is a common one, and one of the reasons that ProDigits can be outfitted with skin-like cosmetic sheaths (called LivingSkin). These “aesthetic restorations” are amazingly life-like, and frankly difficult to distinguish from a natural hand. You can even add artificial hair customized to your own, or add silicone tanning cream for the summer months. Outfitting your ProDigits with a cosmetic cover can help mitigate the unwanted attention that many amputees know too well.

At the Hub for a while we’ve been reporting on the prosthetics revolution, which has really taken off over the last few years. The competing RSPStreeper Bebionic Hand, which uses similar myoelectric sensors along the forearm, hit the market last month with a pricetag of $11,000. Some other prosthetics with more cutting-edge features are still in R&D. The Smart Hand, developed in Europe, is unique in that it sends electrical impulses back to the brain to restore the sensation of touch – but it isn’t yet available to the public.

DARPA is also involved in some cutting-edge prosthetic tech, including the Deka Luke Arm, which uses pads under the feet and shoulder sensors to control the artificial limb. Deka’s arm is not yet on the market, and will likely carry a hefty price tag (plus it’s in competition with the i-Limb, which is already available). Finally, we recently wrote up the most recent Johns Hopkins/DARPA project to actually hardwire a prosthetic directly into the brain, which is just beginning its first human trails and is probably years from marketability (and far beyond most folks’ budgets).

It’s cool to see ProDigits in action, and to get a better sense of how it impacts the lives of its users. While many of these cutting-edge prosthetics remain outside of the financial reach of many amputees (and outside of their insurance plans), they are exciting nonetheless. Time will hopefully bring pricetags down, and give these devices the opportunity to change more lives.

Bebionic is available this month for $11000.

RSLSteeper, creator of the Bebionic artificial hand, has just announced that the hand will be offered at a price of $11,000 (€9000) around the world. Amputees control the prosthetic limb using my-oelectric sensors that read signals on the surface of the skin from residual muscle. To the outside observer it looks like you are moving the hand with your thoughts. This advanced system typically allows you to start using the new limb immediately and get comfortable with it in a few days. While Bebionic is not the only myo-electric hand on the market, it does seem to be the least expensive. That may lead to many amputees choosing to adopt it when it goes on sale later this month. Check out the video below of the launch of Bebionic during the ISPO World Congress in May. Watch amputees completely new to the device try it out around 2:40!

RSLSteeper faces fierce competition from TouchBionics, the maker of the i-Limb Hand, which has been on the market for a few years, and comes with removable digits. As I mentioned when I first reviewed the Bebionic hand in February, the i-Limb is a very similar device, and both have the same four major grips that users can switch between (key, precision, pointer, power). Touch Bionics may have stepped out ahead last month with the release of the i-Limb Pulse, a new hand that allows for pulsing grips and a few other upgrades. However, the Bebionic’s price tag is a powerful advantage, and is about 35% less than i-Limb (~$17k USD at time of writing). Maybe RSLSteeper read the end of my latest article on their device?

We have to remember that most hand amputees still use traditional hook systems that haven’t really changed much since the 40s and that retail for $500 or so. A big reason is that (except for veterans) most amputees can’t get enough money from their insurance agencies to cover expensive prosthetics. $11,000 still isn’t cheap, but it’s a big step in the right direction. Though it would be nice if the fancy synthetic skin covering (available in 19 shades of humanity) was included in that price instead of an additional $600. In any case, major kudos to RSLSteeper for getting a top of the line myo-electric hand closer to fitting in the budget of the average family.

My accolades, however, are notoriously fickle. I would gladly praise Touch Bionics or any other company that can get a myo-electric hand to the market for less than $10k. So keep up the competition, please! Eventually we may see prosthetic hands directly wired into the nervous system, but until we do myo-electrics are still the most advanced systems out there. Not as good as a natural hand, but they come pretty close. Check out the Bebionic in action in the promo video below (apologies for using it for a third time).

*UPDATE: The Bebionic hand will be offered through SPS in the United States, though a USA branch of RSLSteeper will be opening in San Antonion, Texas later this month.

[screen capture and video credit: Bebionic/Mark Hunter]
[source: RSL Steeper press release]

That little blue box is one of the world's smartest knees.

They won’t give you superhuman strength, and they definitely don’t cost six million dollars, but the artificial limbs from Ossur can think to help you walk better. The Rheo Knee, Power Knee, and Proprio Foot prosthetics all carry onboard artificial intelligences that help amputees use their bionic limbs with security and accuracy. Not only do the limbs move in a natural way and provide the strength to climb stairs foot over foot, they learn the user’s gait. Overtime, the bionic limbs will know how you walk better than you do. Check out a French demonstration video of the Power Knee after the break.

Based in Reykjavik, Iceland Ossur is a global leader in prosthetics, braces, and orthopedic education. The founder developed some of the first artificial limbs by testing them on his daughter. The new wave of bionic limbs may be drastically better than older models, but this isn’t enough for current CEO Jon Sigurdsson. His goal is to create limbs that are as good or better than the real thing. Certainly the knees and feet with artificial intelligence go a long way to helping amputees walk and run as well as their peers

Both the Rheo knee and Proprio foot (shown in image above) contain onboard computers that perform minute changes to the prosthetic to help it respond to variations in movement. The Proprio flexes to match terrain, and adjusts the ankle to fit different slopes. The Rheo adjusts actuators to control leg swing. Together, this provides the user with increased security. The embedded AIs can learn an amputees gait in just 15 steps, but continues to adjust as the user grows accustomed to the devices.

It’s the Power Knee, however, that really makes me worry about amputee world domination. This thing is so cool. It provides enough strength for users to climb stairs easily (as seen in the video) and will actually prepare itself for the next step. The AI is also smart enough to match the powered movement with the user’s natural gait. On level ground the knee uses its strength to help propel you forward, letting you walk further without getting tired.

If you’re not terribly excited by watching some guy climb steps, you’re missing the promise of cybernetic enhancement shown in the video. Not only is Ossur pioneering bionic limbs, they are actively developing prosthetics that provide additional strength. All while making them smart and safe enough for use by amputees. Once the technology really gets going, we could see limbs with power and agility far greater than ordinary human function.

I’m not sure if Ossur is seeking to create cyborgs, but they’ve definitely set up the process that could get us there. Under Sigurdsson guidance, the company is seeking to develop, or partner with groups developing, powered motion, neuro-sensing, and osseointegration (bone grafting the prosthetic). They’ve also started Ossur Academy, a seminar system that helps to educate professionals, amputees, and their families in the finer points of artificial limbs and advanced orthopedic supports. Combining technology and teaching is a key ingredient in developing a field quickly.

Whether or not they are ultimately successful, Ossur’s devices show that artificial limbs have as much promise to augment humanity as the exoskeletons we’ve seen from Cyberdyne and Sarcos. The artificial intelligence alone may make bionic limbs the easiest to use. Hopefully, Ossur’s approach will allow them to create a next generation of powered limbs that are better than before. Better, stronger, faster…smarter?

Kepner's surgery underway. Photo courtesy of University of Pittsburgh Medical Center

Kepner, a 57-year-old pastry chef living in Georgia, got his new hands after a nine-hour surgery at the University of Pittsburgh Medical Center. He is still recovering, but has strong circulation in both hands and has showed no signs of organ rejection. The success of his surgery is in part due to a unique new procedure to improve an organ’s chance of being accepted by the body.

Whenever an organ transplant takes place, doctors have to suppress the recipient’s immune system so that it does not reject the new organ outright. This suppression requires toxic drugs that can increase the chances of infection, cancer, diabetes, or other complications. But in the past decade, an innovative procedure has been used to reduce the need for such drugs while still minimizing the likelihood of rejection. Used during Kepner’s transplant, the procedure transplants stems cells from bone marrow into the donated organs, helping the immune system more quickly recognize the hands as part of the body.

Kepner has a long road ahead of him. He’ll need extensive physical therapy before he can use his new hands effectively. This is because when limbs are lost, the areas of the brain responsible for their control get shifted on to other functions. But there’s good news: doctors have recently shown that by reconnecting the nerves to the hands, the motor cortex recognizes their presence and can regain control. It’s not exactly plug-and-play, but the plasticity of the brain will improve Kepner’s ability to use his new hands over time.

The donated hands came from 23-year-old Jeff Keen, who died in an unspecified accident. As an organ donor, Keen’s liver, kidneys, heart, and one lung have already found new homes in five different recipients. Not only that, but his hand donation has made medical history. This was the first double hand donation in the US, and the ninth worldwide. Even single hand transplants are a pretty rare and recent procedure, with the first successful case in the US taking place in 1999 (there have only been six since). It’s an amazing thing how far organ transplants have come, and hard to imagine the future benefits they might still have in store.

Kepner signing up for his upcoming transplant

As we’ve reported in the past, prosthetic technologies are constantly getting better and better. Soon, a prosthetic limb could respond directly to the motor-sensory cortex, providing the same feeling and control as a natural limb. The day will soon come that prosthetics will be so well designed and integrated into the body that many folks will prefer them to natural limbs. But for many people, even a fully functional prosthetic could never replace the real thing, psychologically speaking. Procedures like these transplants show the amazing strides we’re taking to improve the quality of life for amputees.

Our ability to grow new organs in a laboratory setting has increased by leaps and bounds in recent years. Soon, you’ll even be able to custom-order an organ from the company Tengion.  At some point in the near future, growing a new hand might be a real possibility, cutting out the need for transplants between individuals and all the risks of rejection that come with.

But until these practices become safe and widespread, organ donation will continue to prove itself a public good, especially as our ability to perform successful transplants continues to increase. Unless you’re an Egyptian pagan, you probably won’t need your organs after the lights go out. So right now, look down at your hands, and imagine them making pastries with their new owner long after you’re dead. Isn’t that kinda cool?

So what’s it say on your driver’s license?

Braingate reads signals in the motor cortex and translates those signals into movements of a cursor on a screen.

The procedure for implanting Braingate may seem pure science fiction, but it works. Hair-thin gold wires are connected to individual neurons in the brain’s motor cortex. These wires are gathered at a small silicon array and connected to a “pedestal” embedded in the skull. This metallic interface is easy to spot (it’s a big metal nub on the top of the head). From the pedestal, signals can be sent to a computer for translation. By interpreting the motor cortex signals, scientists can determine what your brain would be trying to move (arm, hand, finger, etc) if you weren’t paralyzed.

So you have a metal nub in your head, and some wires poking into your brain, what’s the pay off?  How about the most intuitive mouse ever: by thinking about raising or lowering their hands, patients can move a cursor on the screen of a PC. Squeeze their imaginary hand, and the cursor clicks. The brain signals aren’t completely mapped out yet, and keeping track of one’s thoughts isn’t an easy task, so the cursor tends to jiggle a little and can be hard to move quickly. That being said, it allows individuals who have a hard time even blinking to be able to communicate with others and manipulate devices from their computer. Check out Kathy Hutchinson, one of the first patients, in this story from 60 minutes, the cable connected to her skull seems to be straight out of the Matrix:

Moving Right Along

This amazing technology is the work of many different collaborators, chief among them are Dr. John Donoghue from Brown University, who is also the head of Cyberkinetics, and Dr. Leigh Hochberg from Massachusetts General Hospital. While most of the videos you can find of these two are more than a year old, their work is still developing quickly. Dr. Hochberg began the long process of pilot clinical trials back in February of this year. With the clinical trials will come a better understanding of how to interpret motor cortex signals and increase the tasks able to be performed by patients. Cyberkinetics is already testing a motorized wheelchair, and has plans to develop methods for regaining breathing, bladder, and bowel control.

Expectedly, Braingate is well received publicly and Dr. Hochberg is seeking Investigational Device Exemption from the FDA. Like the Humanitarian Device Exemption given to other implants, this allows the research to continue with human trials quickly. And the technology is developing at a rapid pace. It was only 2005 when we first heard about the beginning experiments to map signals from the brains of rhesus monkeys. The next four to five years will likely see another flurry of development.

I think that this technology is on the brink of runaway growth and success. As Braingate moves forward and is refined, it is poised to mesh with dozens of other related technologies. Singularity Hub has shown you the prosthetic devices, robotic exoskeletons, brain controlled robots, and fMRI mind-reading systems already on the horizon. Soon, I think we’ll see a convergence of these various tools that, while developed separately, have a similar goal: allowing human thoughts to directly affect real-world objects. Once these technologies function better than normal human equivalents we will seem them transition from therapies to everyday utilities.

For now, Braingate returns a precious commodity: control. For many locked-in their own bodies, the best hope they had would be to communicate by blinking. Using a direct neural interface, these same patients have the prospect of writing letters for themselves and maybe even guiding their own wheelchairs. In the future, those prospects may expand to include walking with the help of an exoskeleton or commanding a helper robot. Without a doubt, brain signal technology is taking small steady steps forward every day. Like the Count de Monte Cristo, scientists are slowly digging an escape from the prison that these patients are held in. Together with their patients, they prove that even greater than the terror of being buried alive is the determination to one day be free again.

Even while Dean Kamen and others we have previously reported on work on advanced robotic prostheses, the i-LIMB shows how keeping it simple can still provide amazing improvements to quality of life for amputees.   The i-LIMB uses electrodes placed on the skin of the remaining portion of the patient’s limb, usually on the top and bottom of the forearm.  When the patient moves the muscles that would normally have extended into their hand, the electrodes pick up on electrical signals generated by the muscle movement.   These signals become the basis for individual finger movement within the i-LIMB.

Introduced in 2007 by Scottish company Touch Bionics, the i-LIMB is capable of a variety of unique grip positions that allow the user to balance power and precision as needed.  By extending the index finger alone, patients can type on a keyboard or push buttons.  The user can also grip a key or dinner plate by rotating the thumb to meet the side of the index finger.  The prosthetic is capable of stopping when a sufficient grip is achieved, allowing the patient to grip sensitive objects (e.g. a styrofoam cup) without crushing them.  These more fine-tuned features give the i-LIMB a functionality that enhances the patient’s everyday life.

Patients can choose between a number of cosmetic gloves, including amazingly lifelike skins that blend in naturally with the rest of the body.  The i-LIMB also has a modular construction that allows each finger to be detached by removing one screw.  This way, a digit needing service can be quickly swapped out for a new one, rather than leaving the patient without their prosthetic while it’s being serviced.   The i-LIMB currently costs about $18,000, and is being used by over 600 patients.  More information can be found at the Touch Bionics website.

Check out the i-LIMB in action, as reported by Voice of America:

So what’s next for Touch Bionics?  “We are shortly to release our lower profile i-LIMB Hand which is more appropriate for female and smaller male users,” says Phil Newman, Director of Marketing.  The company is also developing a product for patients missing individual fingers.  “Our next big focus is ProDigits – replacement fingers.  This is a technology for a much larger patient population which has never had a powered finger option before.  We are very excited about this and have a significant number of trial fittings in play.”

Of course, the ideal prosthetic would be hardwired into the nervous system, capable of carrying motor information directly from the brain to the prosthetic and sensory information back up to the brain.  This is exactly the goal of research into Targeted Muscle Reinnervation (TMR) and Targeted Sensory Reinnervation (TSR).  But until these techniques are ready for widespread use, the i-LIMB shows that traditional muscle sensors can improve the quality of life for individuals today.

In the ongoing ethical debates surrounding body augmentation, prosthetics are usually spared accusations of being “unnatural.”  Like antibiotics or hip replacements (to name just a few), prosthetic limbs are widely accepted as beneficial technologies and medical miracles.  Amid the controversies over nanobots or genetic engineering, these less contentious advances should enter into the debate of what a “natural” human being really is.  Natural or not, replacements like the i-LIMB are improving the lives of amputees around the world, and only hint at the possibilities that the future will hold.

Now who can argue with that?

One of the major problems with current prosthetic limbs is that they signal in only one direction, yet true human limbs signal on a bidirectional basis. Not only does the brain send signals to the limb to tell it what to do, but the limb sends signals back to the brain about what it is sensing in the form of pressure, temperature, and so on. The brain uses this sensory information to send adaptive instructions to the limb, allowing for the subtle or rapid changes that define true human agility. From the article:

“Sensory feedback for prosthetics is in the embryonic stages. The best mechanism on the market today consists of a vibrating motor that buzzes against the skin more or less intensely to reflect, for instance, such force factors as grip strength. The DARPA project is gunning for much more than that: researchers want an arm that transmits sensation to the user—pressure, texture, even temperature…with 100 sensors that connect the body’s natural neural signals to the mechanical prosthetic arm to create a sensory feedback loop…”

“As it turns out, the degree of control is directly proportional to the invasiveness of the method.”

The researchers are working with different levels of invasive interaction with the user, but there are two major categories of interaction.

The first category is to connect the muscles or nerve fibers that transmit signals from the brain to the limb. Even when a limb is lost, nerve fibers from the brain still exist up to the point where the limb was cutoff and amazingly they still function years after the loss of the limb. By connecting these nerve fibers to the prosthetic arm the signals from the brain to curl a finger or to clench a fist can still be accessed by interpreting the signals being transmitted across these nerve fibers. From the article:

“In a an individual with both limbs, those nerves travel from the spinal cord down the shoulder over the clavicle and then into the armpit, where they connect to about 80,000 nerve fibers that allow the brain to communicate with the arm.”

The second category is to entirely skip the nerve fibers and link directly into the neurons in the brain. From the article:

“Finally, the most extreme solution is meant for people whose bodies no longer offer any means for interfacing to the artificial limb, for whom even nerve-rerouting surgery may not be an option”

“When electrodes penetrate directly into the motor cortex, embedded electronic circuits intercept the motor neurons firing their instructions and, with the help of complex algorithms, translate the related signals into a language that can control the mechanics of the arms.”

The special report covers a lot of ground, but mostly focuses on DARPA’s Revolutionizing Prosthetics program:

“The program was created in 2005 to fund the development of two arms. The first initiative, the four-year, US $30.4 million Revolutionizing Prosthetics contract, to be completed in 2009, led by Johns Hopkins Applied Physics Laboratory in Laurel, Md., seeks a fully functioning, neurally controlled prosthetic arm using technology that is still experimental. The latter, awarded to Deka Research and Development Corp., Kamen’s New Hampshire–based medical products company (perhaps best known for the Segway), is a two-year $18.1 million 2007 effort to give amputees an advanced prosthesis that could be available immediately “for people who want to literally strap it on and go.” Kamen’s team designed the Deka arm to be controlled with noninvasive measures, using an interface a bit like a joystick.”

Because there are only about 6,000 prosthetic arms needed per year, the market has not been big enough to justify the large investment required to make next generation prosthetic arms. As a result it is amazing to note that commercially available prosthetic arm technology has not changed much in 100 years and is stuck in the “stone age”! Meanwhile prosthetic legs have seen significant investment and are extremely advanced and capable today.

The DARPA funding has literally changed the game by providing the investment necessary to propel prosthetic arms into the current era and beyond. In subsequent posts I will highlight some of the more notable aspects of this report.