First Thought-Controlled Bionic Leg Revealed

A team of researchers at the Rehabilitation Institute of Chicago has revealed clinical applications for the world’s first thought-controlled bionic vleg—a significant milestone for lower limb amputees in the rapidly growing field of bionics. Neural signals were used to safely improve limb control of the leg, which features intelligent engineering, meaning that it can learn and perform activities including seamless transitions between sitting, walking, ascending, and descending stairs and ramps and repositioning the leg while seated.

The bionic leg allows users thought-controlled movement of their prosthetic.

The study focuses on a lower-limb amputee who underwent targeted muscle reinnervation surgery to redirect nerves from damaged muscle in his amputated limb to healthy hamstring muscle above his knee. When the redirected nerves instruct the muscles to contract, sensors on the patient’s leg detect tiny electrical signals from the muscles. A specially-designed computer program analyzes the signals and data from sensors in the leg, instantly decodes the type of movement being attempted, and sends commands to the robotic leg. Using muscle signals, instead of robotic sensors, makes the system safer and more intuitive, the scientists say.

For more information, visit http://www.medicaldesignbriefs.com/component/content/article/17567. To see a video of this device in action, visit http://www.techbriefs.com/tv/bionic-leg.

Bendable Ceramics with Shape Memory

Ceramics are brittle and tend to crack under stress. But, researchers from Massachusetts Institute of Technology, Cambridge, along with colleagues in Singapore, say that they have found a way around that problem, at least for tiny objects.

They have made minuscule ceramic objects that are not only flexible, but also have “shape memory.” When bent and then heated, they return to their original shapes. Shape-memory materials, usually polymers or metals, but not ceramics, can bend and return to original configurations in response to temperature change. The key, they found, to shape-memory ceramics, was thinking small.

When subjected to a load, the molecular structure of the ceramic material deforms instead of cracking. When heated, it returns to original shape. (Credit: Alan Lai)

First, they created tiny ceramic objects made of zirconia, which were invisible to the naked eye. Then, they made the individual crystal grains span the entire small-scale structure, removing the crystal-grain boundaries where cracks are most likely to occur, which resulted in tiny samples of ceramic material with deformability equivalent to about 7 percent of their size. These materials could be used to develop micro- and nanodevices for biomedical applications, such as actuators on a chip, and self-deploying medical devices.

For more information, visit http://www.medicaldesignbriefs.com/component/content/article/17568.

Using Light to Restart Hearts

The “optrode” (left) delivers blue light to the heart via fiber optics, while (right) a red heart cell contains an implanted light-sensitive blue opsin protein that works with (yellow) heart proteins. (Credit: Patrick M. Boyle)

When heartbeats slip into an irregular rhythm, a pacemaker or defibrillator can jolt the heart back into rhythm. But because electricity can cause tissue damage, a team scientists at Johns Hopkins University, Balti more, MD, say there is a gentler option—light.

The engineers are working with optogenetics, inserting light-responsive proteins called opsins into cells. When exposed to light, these proteins become tiny portals, allowing an electric charge in the form of a stream of ions to pass through.

They tested this technique on a heart computer model, incorporating data on techniques to make heart tissue lightsensitive by inserting opsins into cells. Then, they will test how the cells respond when illuminated.

The team plans to conduct virtual experiments to determine how to position and control the light-sensitive cells to help maintain a healthy heart rhythm. They say that the technology could be incorporated into future light-based pacemakers and defibrillators.

For more information, visit http://www.medicaldesignbriefs.com/component/content/article/17166.

Jetprinting Nanostructures with Self-Assembling Material

In this directed self-assembly of a printed line of block copolymer, the density of patterns in the template (bounded by thin lines) is 2x that of self-assembled structures (ribbons).

A team of engineers from the University of Illinois at Urbana- Champaign, the University of Chicago, and Hanyang University in Korea has developed a new approach to fabricating nanostructures for the semiconductor and magnetic storage industries. Their approach combines advanced inkjet printing technology with selfassembling block copolymers, which can spontaneously form ultrafine structures. They increased the resolution of their intricate structure fabrication from approximately 200 nanometers to approximately 15 nanometers.

Recently developed ultra-high-resolution ink-jet printing techniques have demonstrated resolution down to 100 to 200 nanometers, but there have been significant challenges in achieving true nano-scale dimension. They first created either a chemical pattern using traditional processes and then placed a block copolymer atop this pattern using electrohydrodynamic printing, or e-jet printing. The block copolymer self-organizes, directed by the underlying template to form patterns that are at much higher resolution than the template itself.

For more information, visit http://www.medicaldesignbriefs.com/component/content/article/17373.

Teleconcussion Robot to Be Tested at Football Games

The Mayo Clinic, Phoenix, AZ, will be working with Northern Arizona University, Flagstaff, to test a telemedicine robot to assess athletes with suspected concussions during football. With sophisticated robotic technology, use of a specialized remote controlled camera system allows patients to be “seen” by the neurology specialist miles away, in real time. The robot, equipped with a specialized camera system, is remotely operated by a Mayo Clinic neurologist.

This study would be the first to explore whether a remote neurological assessment is as accurate as a face-to-face evaluation in identifying concussion symptoms and making return to play decisions.

For more information, visit http://www.medicaldesignbriefs.com/component/content/article/17212.

Transparent Skull Implant Allows Laser Treatments

(Credit: Mayo Kodera)

A team of researchers from the University of California, Riverside, developed a novel transparent skull implant that could eventually lead to new treatment options for patients with neurological disorders like brain cancer and traumatic brain injury. Their new implant is made of the same ceramic material that is used in hip implants, yttria-stabilized zirconia (YSZ). However, the material is processed to make it transparent.

Since YSZ is well-tolerated by the body, this advancement could allow a permanently implanted window through which doctors can aim laser-based treatments for the brain, without having to perform repeated removals of a portion of the skull to access the brain.

Laser-based treatments show significant promise for many brain disorders but have required performing a craniectomy to access the brain since most medical lasers are unable to penetrate the skull. The transparent YSZ implants developed by the UC Riverside team address this issue by providing a permanent view port through the skull. The inherent toughness of YSZ makes it far more resistant to shock and impact than glassbased implants, enhancing safety, and could minimize the need for protective headgear.

For more information, visit http://www.medicaldesignbriefs.com/vcomponent/content/article/17324.


Medical Design Briefs Magazine

This article first appeared in the November, 2013 issue of Medical Design Briefs Magazine.

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