Amputee can 'feel' with artificial hand
(photo credit: Lund University)
Amputee can feel with
Arobotic hand whose electric signals meld with neurons from the stump has been developed by scientists in Europe and a leading Tel Aviv University professor whose expertise is in creating an interface between electronics and biology. The prototype has been tested on a Swedish amputee, who was able to "sense" his fingers and perform complicated functions after a short training period. The SmartHand project is led by Dr. Fredrik Sebelius and Prof. Thomas laurel from Lund University and Prof. Goran Lundborg from the Hand Surgery Center in Malmo, Sweden. The project includes scientists from Sweden, Italy, Ireland, Denmark and Iceland as well as Israel and is supported by the EU Sixth Framework Agreement. The first patient, Robin Ekenstam, was given artificial sensory feedback controlled by his neurons, giving him some apparent sensation in the fingers. Sensors in the prosthesis record feeling, and then the signals are relayed back to an actuator placed on the skin of the limb. A push on a finger can create a sensation as amputees typically have a phantom map of the amputated hand on the residual limb. The team integrated four electrical motors and 40 sensors in the hand. TAU Prof. Yosi Shacham, who manages a lab investigating micro-and nano-bio interfacing, has been working for years on flexible electrodes that could last 20 years and serve as the interface between nerves and electronics. He is collaborating with a team at the Tyndal Institute in Ireland that developed the electrodes. The development of the neural interface has many obstacles to overcome before it can be used routinely, but with the SmartHand, the goal is one step closer. In a recent interview with the Swedish TV, Ekenstam said: "I am using muscles I not used for years. When I hold solid objects I feel them at the end of my fingers. This is weird, since I do not have fingers. This is an amazing system." SNIFFING OUT MEMORIES Certain aromas - like that of the madeleine pastries recalled by French author Marcel Proust - are bound up in memories. Now researchers at the Weizmann Institute of Science in Rehovot have managed to figure out how the mechanism works and published their findings in the journal Current Biology. Graduate student Yaara Yeshurun, together with Profs. Noam Sobel and Yadin Dudai of the institute's neurobiology department, thought the key might not necessarily lie in childhood, but rather in the first time a smell is encountered in the context of a particular event. That is, the initial association will somhow leave a unique and lasting impression. To test this idea, the scientists devised an experiment: First, in a special smell laboratory, subjects viewed images of 60 objects, each presented simultaneously with either a pleasant or an unpleasant odor generated in an olfactometer. Next, the subjects were put in a functionalMRI (fMRI) scanner to measure their brain activity as they reviewed the images they'd seen and attempted to remember which odor was associated with each. Then, the whole test was repeated - images, odors and fMRI - with the same images, but different odors accompanying each. Finally, the subjects came back one week later, to be scanned again while viewing the objects one more time and being asked to recall the odors associated with them. The scientists found that after one week, even if the subject recalled both odors equally, the first association revealed a distinctive pattern of brain activity. The effect was apparent whether the smell was pleasant or unpleasant. This unique representation showed up in the hippocampus, a brain structure involved in memory, and in the amygdala, involved in emotion. The pattern was so profound that it enabled the scientists to predict which associations would be remembered just by looking at the brain activity following the initial exposure. The scientists could look at the data on the first day of the experiment and predict which associations would come up seven days later. To see if other sensory experiences might share this tendency, the scientists repeated the entire experiment using sounds rather than smells; they found that sounds did not arouse a similar distinctive first-time pattern. Childhood olfactory memories may be special not because childhood is special, but simply because those years may be the first time we associate something with an odor. " EILAT RESEARCH SHIP SETS SAIL An sophisticated $1.3 million research ship has been launched at the Interuniversity Institute for Marine Sciences in Eilat. Purchase and outfitting of the ship was financed by the Planning and Budgeting Committee of the Council for Higher Education, the Science and Technology Ministry, the Hebrew University of Jerusalem, the Weizmann Institute of Science in Rehovot and private donors. HU Prof. Aaron Kaplan, who heads the Interuniversity Institute, said that "over the years the institute rented various vessels for teaching and research, but never was able to find one totally suitable. Now we have been able to realize a dream of many years. The fact that we now have a suitable ship will greatly advance marine research in Israel." Kaplan noted that marine research has acquired increased attention in recent years due to new scientific approaches and the increased use of marine biological models for medical research. This, in turn, has brought more money into the field. "The new ship will make it possible to advance research on the unique organisms found in the Gulf of Eilat and in the ocean itself," said Kaplan. "The technology on the ship will make it possible to further the monitoring of the gulf, and the development of means to cope with possible crises such as an oil spill," he said.