Tag Archives: prosthesis

Retired truck driver can walk on two legs again thanks to Terminator-like bionic leg

Kerry Finn training with the “Utah Bionic Leg” — a self-powered prosthetic limb that allows amputees to walk with vigor and balance. Credit: Mark Helzen Draper/University of Utah College of Engineering.

A vascular disease due to type 2 diabetes claimed the left leg of 60-year-old Kerry Finn, a retired truck driver from Salt Lake County, Utah. For a long time, Finn had been using a standard prosthetic until last year when he became one of 10 human subjects that would go on to trial the world’s first truly bionic leg.

“If you’ve ever seen ‘The Terminator,’ that’s what it was like,” Finn says about the experience of testing the bionic leg over the standard prosthetic he normally uses. “It made me feel like I could do things I could not do before. Every time I made a step, it was an awesome feeling.”

The bionic leg developed by researchers at the University of Utah is completely self-powered and has an integrated computer processor that controls motorized joints in the ankle and knee.

Unlike a standard prosthesis, the Utah Bionic Leg employs an array of sensors, computers, motors, and artificial intelligence — all of which are working in conjunction to mimic the biomechanics of a real leg as closely as possible. As such, the bionic leg offers users more power and causes less stress on the body than a standard prosthesis.

“If you walk faster, it will walk faster for you and give you more energy. Or it adapts automatically to the height of the step. Or it can help you cross over obstacles,” says Tommaso Lenzi, assistant professor of mechanical engineering at the University of Utah and the project lead of “Utah Bionic Leg.” The project recently received two grants to further advance the technology, a $2.2 million award from the National Institute of Health and the other a $600,000 grant from the National Science Foundation.

Kerry Finn (left) and Tommaso Lenzi. Credit: Mark Helzen Draper/University of Utah College of engineering.

The bionic leg weighs only 2.7 kg (6 pounds), or about half as much as standard prosthesis. This can be a huge advantage for elderly people like Finn who have lost one of their limbs. The light frame was achieved through a combination of light materials (aluminum and titanium) and clever design that keeps redundancy to a minimum.

“Every time you take a step, it’s powered, and it gives a certain kick. It also gives me the ability to take two steps at a time going up stairs,” Finn says. “With this leg, it’s less strain on my stump. You don’t have to work as hard. And it takes a lot of the stress off the body.”

In the future, the researchers plan on using government grants to further improve their bionic leg design. They would like to improve the prosthetic’s ability to anticipate a user’s movements by tracking muscle activity in the residual limb.

“The ability to walk is essential to your life and being able to pursue whatever you want to do. When just standing up is a pain and when walking means being afraid of falling, you just don’t go on with your life and you are stuck at home,” Lenzi says. “This is about making bionics accessible for all people and not just those who are young and high performing.”

The artificial hand made at Cornell University was able to tell apart tomatoes by their softness and find the ripest one. Credit: Cornell University.

Optics-based tech lends a human touch to soft robot arm

The artificial hand made at Cornell University was able to tell apart tomatoes by their softness and find the ripest one. Credit: Cornell University.

The artificial hand made at Cornell University was able to tell apart tomatoes by their softness and find the ripest one. Credit: Cornell University.

A new kind of robotic arm based on stretchable optical waveguides boasts unprecedented pressure and texture sensing. Modeled on the human arm, the prosthesis has sensors embedded inside it allowing it to ‘feel’ whether a fruit is ripe or more pressure can be exerted, for instance.

“Most robots today have sensors on the outside of the body that detect things from the surface,” said Cornell doctoral student Huichan Zhao. “Our sensors are integrated within the body, so they can actually detect forces being transmitted through the thickness of the robot, a lot like we and all organisms do when we feel pain, for example.”

Elastomeric optical waveguides are tubes packed inside with LEDs and photosensors. Using a combination of soft lithography and 3-D printing, Zhao and colleagues made the core through which light propagates and the cladding which houses the LED and the photodiode.

The fabrication method had been previously used by Cornell researchers to make all sorts of soft and malleable artificial body parts that resembled tentacles and even a squishy robo-octopus. The four fingers and the thumb are pneumatically actuated and mounted on a 3D-printed rigid palm.

Human-like interactions were tested against various objects. Credit: Cornell University.

Human-like interactions were tested against various objects. Credit: Cornell University.

As the elastomeric tubes get bent, the light’s intensity shone by the LEDs and measured by the photodiode can increase or decrease. It’s this variable loss of light intensity that allows the prosthesis to sense its environment.

Most robotic prostheses are very rigid, held together with nuts and bolts, and sense their surroundings with sensors that conduct electrical signals. Now, a whole new range of possibilities is opened to science because we can use light just as well and soft robotics closely mimics human hands. Such machines can stretch, twist, scrunch and squish, change shape or size, wrap around objects and perform tasks impossible by rigid robotics standards. In fact, it seems there’s a soft robotics revolution just waiting to happen.

“If no light was lost when we bend the prosthesis, we wouldn’t get any information about the state of the sensor,” said lead author Robert Shepherd, assistant professor of mechanical and aerospace engineering. “The amount of loss is dependent on how it’s bent.”

The prosthesis was put to the test with various tasks. In one experiment, the soft arm was able to scan three tomatoes and determine, by softness, which was the ripest.

Shepherd says the artificial soft arm could be made for as little as $50 (batteries and compressor tank not included).

The next step is to have the prosthesis interface with the brain so that a human can control it solely with thoughts. Elsewhere, in manufacturing plants or automated environments, this robot hand could handle special assembly lines or assist humans with its soft touch.

The findings were reported in the journal Science Robotics


The first mind-controlled leg prosthesis is amazing!

A freak accident from his childhood in Iceland caused Gudmundur Olafsson’s right ankle to collapse. After 28 years of living in pain and more than 50 surgical operations he decided to amputate his lower leg entirely. For years, he wore the  Proprio Foot – a prosthetic motorized ankle developed by an Icelandic company called Ossur which can automatically adjust the angle of the foot using its built-in sensors. Now, Olafsson prosthesis got a major upgrade: his new Proprio is controlled subconsciously by electrical signals sent from his brain to special sensors directly embedded in his muscles, all via the nerves in the muscle itself. Then a decoded signal is sent to a control unit which directs all the fine moving parts that make up his new, robotic leg. All his intentions are translated seamlessly by the sensors and Olafsson, now 48, can walk almost entirely like a normal person. “The first time, to be honest, I started to cry,” said Olafsson.


The brain-controlled bionic Proprio Foot. Credit: Ossur


“Gummi” Olafsson is among two patients who received this experimental prosthesis. It’s been 14 months now since he’s wore it, and each day it’s getting better. What’s amazing is that there’s strain put on the muscles again, so they’ve started moving away from atrophy – always a big concern.

Image: Ossur

Image: Ossur

“You have to learn how to use those muscles again,” says Olafsson. “How to tighten them up, in front and back. And that’s the main thing. Those muscles start getting bigger, so you get better at walking. I have more stamina. My gait is better. I don’t limp as much,” he said to PopSci.

At the very core of this technology are the myoelectric sensors (IMES). Ossur claims these are “lifetime sensors” since they don’t require any batteries. The tiny sensors (3 millimeters-by-80 millimeters) are instead powered by magnetic coils embedded in the socket – a hollow component that fits over the residual limb and connects to the prosthesis. Compared to what Olafsson had to deal with in his youth, the implant surgery was a piece of cake. It only took 15 minutes and the sensors fit in a single-centimeter-long incision.

Image: Ossur

Credit: Ossur

I couldn’t find anything about cost, though. These sort of details will likely surface once the prosthesis is out of clinical trial. Right now, Ossur is still busy collecting data and improving their prosthesis. For what it’s worth, it all looks very promising already!

Londsdale face

After cancer ate out his face, this 74-year-old now uses a 3-D printed mask. Photos speak for themselves

Since 1990, Keith Londsdale went through no less than 45 different surgical procedures to remove basal cell carcinoma tumors, one of the most common skin cancers. The man survived the ordeal, but was left deformed as doctors had to remove his nose, upper jawbone and cheekbones. Basically, the 74-year-old-man now has a huge hole in his face.

Londsdale face

Credit: Nottingham’s Queen’s Medical Center

Londsdale tried various prosthesis, but it was quite clear traditional masks couldn’t help him live a normal life, like eating or speaking properly. So the old man’s son asked Jason Watson, a reconstructive scientist at Nottingham’s Queen’s Medical Center to try building a 3-D prosthesis for his father; one that would be custom tailored. Because his face was so deformed, the researchers built a mask based on his son’s face instead.  Watson and colleagues first scanned Scott Londsdale’s face (the son), then used an algorithm to design a prosthesis that would fit and mold with the gap left in the face of his father. The mask was 3-D printed out of silicon, with a wax-based molding.

“The ­process of rebuilding Keith’s face was unique in many ways but this was certainly the first time we’ve created a prosthesis based on a family resemblance,” said Watson.

It was only yesterday that ZME Science reported how three babies were saved from an incurable disease after doctors used 3-D printed implant. The transformative effects of 3-D printing are now upon us.

Keith and Scott Landsdale, side by side. Credit: t Nottingham’s Queen’s Medical Center

Keith and Scott Landsdale, side by side. Credit: t Nottingham’s Queen’s Medical Center