Wearable Robot Helps Paralytic People Walk

Scientists have designed a wearable lower limb robot exoskeleton with natural knee movement to help stroke and spinal cord injury patients regain the ability to walk and strengthen their muscles. Wearable “robot-assisted training” is quickly emerging as a method to improve gait rehabilitation. Researchers from Beihang University in China and Aalborg University in Denmark said that the robotic exoskeleton was intended to help stroke patients strengthen their physical fitness, aid the rehabilitation training of paralyzed patients, or to assist those who need help performing daily activities. The team focused on the knee joint, one of the most complex mechanical systems within the human body and a critical player during gait. The knee joint’s motion is actuated by several skeletal muscles along its articular surfaces and its centre of rotation moves. Researchers wondered if a parallel mechanism similar to skeletal muscles would be useful for designing a bionic knee joint. This design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton. The exoskeleton taps a hybrid serial parallel kinematic structure consisting of a one degree of freedom (DOF) hip joint module and a 2-DOF knee joint module in the sagittal plane. A planar 2-DOF parallel mechanism helps to fully accommodate the motion of the human knee – enabling rotation and relative sliding. When wearing the exoskeleton, its movement should be synchronized and consistent with a patient’s natural movement.

Explained: Why Pints Spill But Straw Do Not

It is not only the size, but the shape of a tube that determines whether a liquid will spill out of it when tipped over. Glasses of liquid, when turned horizontally, inevitably spill. This is not necessarily the case, however with thin straws, which, when turned on their sides, can retain liquid in them. This simple relationship was thought to be based on the size of the tube opening but researchers from University of Oxford have determined that this rule does not always hold true. The shape of the tube turns out to be important too, and if it is squashed enough – forming an elliptical shape – then no matter how thin the straw is the liquid will always spill out. This new discovery has applications in technologies that deal with liquids on small scales – such as biomedical diagnostics, oil recovery and inkjet printing – where choosing the right tube shape could be as important as its size.

'Martian' Redux? NASA Plants Lettuce On ISS

NASA has planted lettuce on the International Space Station to learn how to grow fresh food in space which may help prepare astronauts for future manned mission to Mars. Astronaut Shane Kimbrough initiated the Veg-03 experiment, one of his first science assignments, and has planted the third on orbit crop of red romaine lettuce. Operations were little slower than expected, but all plant pillows were successfully primed for the first time in Veg series. Plant pillows are small pouches containing a growth medium, fertilizer and seeds. The Veg-03 crop will be the team’s first on-orbit attempt at a new, repetitive harvest technique termed ‘Cut-and-Come-Again’. Once the plants are four weeks old, a selection of leaves can be harvested for a bit of fresh lettuce.