A neural interface device allows patients to control a robotic arm with their minds.

Cathy Hutchinson hasn’t moved her limbs of her own volition for 15 years, but by imagining she was using her own hand, she controlled a robotic arm to pick up a thermos of coffee and took a sip. The technology is a neural interface system called BrainGate2, currently in clinical trials, which connects Cathy’s brain to a robot. The device is the result of over 10 years of research at Brown University and an extension of the first BrainGate in 2006, which allowed patients to control a computer cursor on a screen.

Cathy was one of two patients on the study, which was recently reported in Nature, who suffer from tetraplegia, a condition in which communication between the brain and the rest of the body is disconnected either through a stroke or damage to the spinal cord. Prof. John Donoghue, principal investigator on the BrainGate project, described their approach to Nature: “Our idea is to bypass that damaged nervous system and go directly from the brain to the outside world, so the brain signals cannot control muscles but machines and devices, like a computer or a robotic limb.” When Cathy controlled the arm with her mind to bring the coffee over for her to drink, the team was amazed.

Check out the video to see the moment for yourself:

As we previously introduced, BrainGate2 has three components: a sensor, a decoder, and assistive technology. The sensor consists of an array of 96 hair-thin electrodes the size of a children’s aspirin that is surgically implanted into the motor cortex, the part of the brain that controls body movements. Neural activity is relayed through a gold wire to a computer (the decoder), which interprets the signals and produces a command for the robot arm. Two robotic arms have been tested in the study: the DEKA Arm System and the heavier DLR Light-Weight Robot III arm from the German Aerospace Centre.

Cathy has had the BrainGate sensor implanted in her brain for the last five years, as she was involved in previous studies with the system. During testing that took place one year ago, Cathy was able to successfully raise the coffee and drink from it using BrainGate2 four times out of six attempts. In another test of the BrainGate2 system, the two patients had to reach out and grab a ball in a 30-second window, and Cathy experienced better success with the DEKA arm (46 percent success rate) than the DLR arm (21 percent).

Prof. Donoghue explained to Nature that controlling the robotic arm is much more complicated than moving the cursor on a screen in the original BrainGate study: “To move from this type of two-dimensional movement to movements involving reaching out for an object, grasping it and then guiding it in three-dimensional space is a huge step for us. It seems like more than one additional dimension in complexity.” He emphasized that a lot of work needed to be done to improve the rate and accuracy of motion as well as improving the decoding algorithms for more complex motions.

The Brown researchers already have plans to make the sensor wireless and improve the robotic arm to allow for more complicated tasks, such as brushing teeth. In the long term, an alternative approach is being considered in which the signals from the decoder are transmitted to the patient’s muscles, allowing them to reuse their own limbs.

This is a huge stride for the field of brain-computer interfaces, and will undoubtedly inspire more surgical and nonsurgical approaches. Controlling objects with the mind makes for great science fiction, but people who suffer from conditions that prohibit motion due to spinal cord damage are on the cusp of regaining a part of themselves that they thought was lost forever. Furthermore, similar technologies will open up even more possibilities for mind control of objects as the programs that can translate neural signals into instructions become more sophisticated.

“All of us were standing in awe, more or less, because we’re watching her drinking the coffee,” Prof. Donoghue commented in the video. “It was really such a stunning scene.”

[Media: YouTube]

[Sources: Arstechnica, BrainGate, Nature, Nature Video]

Dean Kamen shares moving stories about his development of prosthetic arms for veterans.

Thousands lose their arms every year to accidents, disease, and war. For centuries the best technology they were offered was a hook on a stick. Now Dean Kamen wants to give them much, much more. In his impassioned speech from  TEDMED he shows us the amazing story of people who have lost part of themselves but who now have hope on the horizon. You have to see this video! Kamen’s research firm, Deka, has been working tirelessly to develop a prosthetic arm for DARPA, affectionately dubbed the Luke Arm after the Star Wars character. The progress he and his team have made – clinical trials and five active participants starting just 15 months after inception – is incredible. Yet it is the amputees, the ultimate recipients of his work, that have grabbed Kamen’s admiration and dedication. Listen to him explain why in the video below.

There’s no doubt that Dean Kamen is a rock star of technology. He has 440+ patents, he invented the Segway, and is the founder of FIRST. Still, I was surprised to hear about the confidence DARPA had in his abilities. They wanted a hand that could pick up a grape or raisin (3:23 in the video) that weighed less than 9 lbs, and was completely self contained. And they wanted in less than 2 years (5:40)! Kamen gave them a working prototype in one. You can see the Luke Arm in action starting at 8:15, with the grape test at 9:05. The focus of the talk, however, were the experiences Kamen shared with veterans at Walter Reed (10:00) and other locations, including a quadruple amputee (13:38), and a crowd of 3500 soldiers and family members (15:20).

To be honest, I tend to avoid impassioned speeches. I’m more of a cold hard facts kind of guy. I must admit though, that Kamen’s plea for funding veterans’ prostheses hit home. We should be spending more money and devoting more research to getting upper body artificial arms out of the dark ages. However, I would extend Kamen’s plea to include all amputees everywhere. Prosthetic projects should begin with veterans (that’s where the money and passion is) but they need to extend to everyone who has lost a limb. Lower body prosthetics have already made huge leaps in improvement in the last decade. Artificial arms need to undergo a similar revolution. The Deka Luke Arm is a good contender to make it happen, but there are other artificial arms with different (perhaps even better) approaches. With adequate funding each of these projects could help us find the next generation of arms and hands that help amputees recover the capabilities they have lost. I agree with Kamen’s conclusion that we should continue such research until non-amputees are jealous of the artificial limbs we can provide. Heh…now that I think about it, why stop there?

[screen capture and video credit: TEDMED]
[source: TEDMED, Deka]

Deka's Luke Arm is in clinical trials. Will it find favor with amputees?

The future of prosthetics isn’t certain, and we’ve seen so many different next generation devices, it’s hard to know which will ultimately arise as the standard. For legs, there are spring like mechanical struts that can outperform their biological counterparts, and there are complex electronic knees and feet that contain narrow artificial intelligence. Prosthetic hands, however, haven’t evolved much in the past 60 years. But that’s about to change. We’ve seen many different robotic hands in development, and one of the most popular in the press has been Deka’s Luke Arm. Dean Kamen, inventor of the Segway scooter and head of Deka, helped design the electronic arm to fit the needs and desires of modern amputees. The Luke Arm went into clinical trials this summer and could become the prosthetic limb of choice for US soldiers returning from Iraq and Afghanistan. Yet, despite the Luke Arm’s media presence (check out the 60 Minutes segment video after the break), I’m not certain it’s going to beat the competition.

For those who missed our first story on Deka’s Luke Arm, I should explain that it is controlled by pads under the feet and attached to shoulders muscles. Like a complex video game, users press on these pads to get the limb to perform desired actions. This is a robust system that allows for a precise level of control. It also takes a while to get used to. Competing prostheses, like i-Limb, use myoelectric sensors that can read nerve signals in muscles. Essentially, you think about moving your missing hand, and the prosthetic performs the action. The two approaches, joystick versus mind-control, seem grossly mismatched in the favor of the myoelectric sensors. How is the Deka arm staying competitive?

Well, largely I think the Luke Arm is winning because it is already able to start clinical trials, has Dean Kamen attached to the project, and is a remarkable piece of machinery. No doubt, the Luke Arm performs very well. It’s customizable, modular, and robust. At only 8 lbs (3.6 kg), it contains electric motors that give it 18 degrees of freedom (the human arm has 22) and pressure control. A vibrating device, called a tactor, gives the user feedback sensation that allows him or her to stop the Luke Arm before it crushes an object. In the video you can see how the device is gentle and sensitive enough to pick up a grape.

As mentioned, the Luke Arm is part of DARPA’s Revolutionizing Prosthetics program. Deka received close to $18 million for the development of its device, but $30.4 million went to John Hopkins Applied Physics Lab for an alternate prosthetic that uses myoelectric sensors. That device, and APL researcher Jonathan Kuniholm, is shown towards the end of the 60 Minutes segment.

DARPA is hedging it’s bets, spreading money around to see which projects will bear fruit. Smart idea. The Luke Arm’s current trial utilizes the control pads we discussed earlier, but Kamen isn’t ruling out the use of myoelectric sensors in the future. Between the APL and Deka, DARPA is bound to get at least one fieldable prosthetic very soon.

But if you’re not a veteran, neither DARPA project may really help you much. The Luke Arm is slated to cost $100,000+, and a similar price is likely for the APL limb. That’s well beyond the means of most amputees if they do not have the insurance coverage provided by the Veteran’s Administration. The i-Limb is offered at a cheaper price (near $18,000) and is already being tested by 600 users. As most amputees are not veterans, I think that the Luke Arm has a good chance of being priced out of a large market share.

Which is why I was very interested in Jonathan Kuniholm’s Open Prosthetics project. The same biomedical engineer working at APL (on the DARPA grant) is an advocate of open source solutions and hopes that a cheap and reliable alternative could be provided for those without the means to spend hundreds of thousands of dollars. Kuniholm gave an amazingly frank and thought-provoking interview to NPR’s Fresh Air earlier in the month. He discussed the budget limitations of amputees, the bias non-amputees have on appearance over function, and the media’s preference for hyperbolic stories (around 11:02). Give it a listen:

After hearing Kuniholm criticize the media for telling just two versions of technology stories (“this device is amazing, it’s going to change everything” or “this device is a horrible waste of money”) I am inclined to give a very measured outlook on the future of prosthetics. The Luke Arm is a great piece of machinery, and it’s likely to be ready soon, but it could be too costly to own and too difficult to operate. Myoelectric devices could offer some amazing possibilities, but they aren’t here yet. Surgically augmented devices, like the Smart Hand, could offer realistic feedback via nerve connections and completely outperform any other limb. But those devices are years from completion. The bottom line is that the first commercially available next-generation upper body prosthetic could be the Luke Arm, but it is certainly not going to be the last. Whichever device eventually sets the standard for limb replacement will have to be adaptable, affordable, and above all functional. May the best hand win.

[photo credit: IEEE Spectrum]
[video credit: 60 minutes via CNET]
[audio credit: NPR Fresh Air]