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Livorno, Italy

Jelinek F.,Technical University of Delft | Gerboni G.,BioRobotics Institute | Henselmans P.W.J.,Technical University of Delft | Pessers R.,Pessers Engineering | Breedveld P.,Technical University of Delft
Minimally Invasive Therapy and Allied Technologies | Year: 2015

Introduction: Steerable instruments are a promising trend in minimally invasive surgery (MIS), due to their manoeuvring capabilities enabling reaching over obstacles. Despite the great number of steerable joint designs, currently available steerable tips tend to be vulnerable to external loading, thus featuring low bending stiffness. This work aims to provide empirical evidence that the bending stiffness can be considerably increased by using fully actuated joint constructions, enabling left/right and up/down tip rotations with the minimum of two degrees of freedom (DOF), rather than conventional underactuated constructions enabling these rotations with more than two DOF. Material and methods: A steerable MIS instrument prototype with a fully actuated joint construction was compared to state-of-the-art underactuated steerable instruments in a number of tip deflection experiments. The tip deflections due to loading were measured by means of a universal testing machine in four bending scenarios: straight and bent over 20°, 40° and 60°. Results and conclusions: The experimental results support the claim that a fully actuated joint construction exhibits a significantly larger bending stiffness than an underactuated joint construction. Furthermore, it was shown that the underactuated instrument tips show a considerable difference between their neutral positions before and after loading, which could also be greatly minimised by full actuation. © 2014 Informa Healthcare. Source


Vitiello N.,SantAnna School of Advanced Studies | Lenzi T.,SantAnna School of Advanced Studies | Roccella S.,SantAnna School of Advanced Studies | De Rossi S.M.M.,SantAnna School of Advanced Studies | And 5 more authors.
IEEE Transactions on Robotics | Year: 2013

This paper presents the design and experimental testing of the robotic elbow exoskeleton NEUROBOTICS Elbow Exoskeleton (NEUROExos). The design of NEUROExos focused on three solutions that enable its use for poststroke physical rehabilitation. First, double-shelled links allow an ergonomic physical human-robot interface and, consequently, a comfortable interaction. Second, a four-degree-of-freedom passive mechanism, embedded in the link, allows the user's elbow and robot axes to be constantly aligned during movement. The robot axis can passively rotate on the frontal and horizontal planes 30° and 40°, respectively, and translate on the horizontal plane 30 mm. Finally, a variable impedance antagonistic actuation system allows NEUROExos to be controlled with two alternative strategies: independent control of the joint position and stiffness, for robot-in-charge rehabilitation mode, and near-zero impedance torque control, for patient-in-charge rehabilitation mode. In robot-in-charge mode, the passive joint stiffness can be changed in the range of 24-56 N·m/rad. In patient-in-charge mode, NEUROExos output impedance ranges from 1 N·m/rad, for 0.3 Hz motion, to 10 N·m/rad, for 3.2 Hz motion. © 2004-2012 IEEE. Source


News Article
Site: http://news.yahoo.com/science/

Using a bionic fingertip, an amputee for the first time has been able to feel rough and smooth textures in real-time, as though the fingertip were naturally connected to his hand. After Luke Skywalker got his hand cut off during a duel with Darth Vader in "Star Wars," the young Jedi received an artificial hand that helped him both grip and feel again. Scientists worldwide are seeking to make this vision from science fiction a reality with prosthetic limbs that are wired directly into the nervous systems of their recipients. Researchers experimented with amputee Dennis Aabo Sørensen from Denmark, who damaged his left hand more than a decade ago while playing with fireworks. Doctors immediately amputated the appendage after Sørensen was brought to a hospital. [Bionic Humans: Top 10 Technologies] "I still feel my missing hand — it is always clenched in a fist," Sørensen said in a statement. The researchers had connected Sørensen to a bionic hand that helped him to tell whether an object held in the prosthetic was soft or hard, round or square. Now the scientists wanted to see if they could improve his ability to detect more subtle characteristics, like rough or smooth textures. "The more we are able to reach the complexity of the natural sense of touch, the more usable the device will be," study co-author Silvestro Micera, head of the translational neural engineering lab at the Swiss Federal Institute of Technology in Lausanne, told Live Science. The researchers connected a postage-stamp-size artificial fingertip to electrodes surgically implanted to nerves in Sørensen's upper left arm above his stump. A machine then ran the bionic fingertip over different pieces of plastic that were engraved with smooth or rough patterns. Sensors in the artificial fingertip generated electrical signals that were translated into a series of electrical spikes, imitating the language of the nervous system. These spikes were then delivered to Sørensen's nerves. "One of the most amazing things we saw during the experiments was the fastness of the learning process," said lead study  author Calogero Oddo, a bioengineer at the Sant'Anna School of Advanced Studies' BioRobotics Institute in Pisa, Italy. "Dennis [Sørensen] was able to perceive texture about 15 minutes after the first delivery of electrical spikes." Sørensen could distinguish between smooth and rough surfaces 96 percent of the time, making him the first person in the world to recognize texture using a bionic device, the researchers said. [Body Beautiful: The 5 Strangest Prosthetic Limbs] "The stimulation felt almost like what I would feel with my hand," Sørensen said in the statement. "I felt the texture sensations at the tip of the index finger of my phantom hand." The researchers also experimented with non-amputees who were temporarily attached to the artificial fingertip through electrodes stuck into nerves in their arms. These volunteers were able to distinguish between rough and smooth textures only about 77 percent of the time. Sørensen probably did better than the non-amputee volunteers because the electrodes were surgically implanted into the amputee's nerves, whereas they were not as securely attached to those of the non-amputees, Oddo said. When the researchers scanned the brains of both Sørensen and the non-amputee volunteers, they found that Sørensen's brain activity while using the artificial fingertip was analogous to that of non-amputees using their own fingers. This suggests the sensations from the bionic fingertip accurately resemble the feeling of touch from real fingers, the scientists said. The researchers have already integrated the new fingertip into a prosthetic hand. Micera said they plan for patients to use this advanced bionic device in experiments before the end of 2016. "Hopefully, we will have proof of long-term use in two to three years and transfer to clinical practice in five to 10," Micera said. Currently, the fingertip can discern textures on a millimeter scale, Oddo said. "When it comes to discriminating a piece of wood from a piece of paper, a piece of cotton, a piece of silk, and so on, those materials differ on an even finer level, on a micron level," Oddo told Live Science. He added that they have developed an artificial fingertip that can discriminate such fine textures, and they hope to have patients test it on items such as clothes. The scientists detailed their findings online today (March 8) in the journal eLife. Copyright 2016 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


News Article
Site: http://www.biosciencetechnology.com/rss-feeds/all/rss.xml/all

An amputee was able to feel smoothness and roughness in real-time with an artificial fingertip that was surgically connected to nerves in his upper arm. Moreover, the nerves of non-amputees can also be stimulated to feel roughness, without the need of surgery, meaning that prosthetic touch for amputees can now be developed and safely tested on intact individuals. The technology to deliver this sophisticated tactile information was developed by Silvestro Micera and his team at EPFL (Ecole polytechnique fédérale de Lausanne) and SSSA (Scuola Superiore Sant'Anna) together with Calogero Oddo and his team at SSSA. The results, published in eLife, provide new and accelerated avenues for developing bionic prostheses, enhanced with sensory feedback. "The stimulation felt almost like what I would feel with my hand," said amputee Dennis Aabo Sørensen about the artificial fingertip connected to his stump. He continues, "I still feel my missing hand, it is always clenched in a fist. I felt the texture sensations at the tip of the index finger of my phantom hand." Sørensen is the first person in the world to recognize texture using a bionic fingertip connected to electrodes that were surgically implanted above his stump. Nerves in Sørensen's arm were wired to an artificial fingertip equipped with sensors. A machine controlled the movement of the fingertip over different pieces of plastic engraved with different patterns, smooth or rough. As the fingertip moved across the textured plastic, the sensors generated an electrical signal. This signal was translated into a series of electrical spikes, imitating the language of the nervous system, then delivered to the nerves. Sørensen could distinguish between rough and smooth surfaces 96 percent of the time. In a previous study, Sorensen's implants were connected to a sensory-enhanced prosthetic hand that allowed him to recognize shape and softness. In this new publication about texture in the journal eLife, the bionic fingertip attains a superior level of touch resolution. This same experiment testing coarseness was performed on non-amputees, without the need of surgery. The tactile information was delivered through fine, needles that were temporarily attached to the arm's median nerve through the skin. The non-amputees were able to distinguish roughness in textures 77 percent of the time. But does this information about touch from the bionic fingertip really resemble the feeling of touch from a real finger? The scientists tested this by comparing brain-wave activity of the non-amputees, once with the artificial fingertip and then with their own finger. The brain scans collected by an EEG cap on the subject's head revealed that activated regions in the brain were analogous. The research demonstrates that the needles relay the information about texture in much the same way as the implanted electrodes, giving scientists new protocols to accelerate for improving touch resolution in prosthetics. "This study merges fundamental sciences and applied engineering: it provides additional evidence that research in neuroprosthetics can contribute to the neuroscience debate, specifically about the neuronal mechanisms of the human sense of touch," said Calogero Oddo of the BioRobotics Institute of SSSA. "It will also be translated to other applications such as artificial touch in robotics for surgery, rescue, and manufacturing."


News Article
Site: http://www.rdmag.com/rss-feeds/all/rss.xml/all

An amputee was able to feel smoothness and roughness in real-time with an artificial fingertip that was surgically connected to nerves in his upper arm. Moreover, the nerves of non-amputees can also be stimulated to feel roughness, without the need of surgery, meaning that prosthetic touch for amputees can now be developed and safely tested on intact individuals. The technology to deliver this sophisticated tactile information was developed by Silvestro Micera and his team at EPFL (Ecole polytechnique fédérale de Lausanne) and SSSA (Scuola Superiore Sant'Anna) together with Calogero Oddo and his team at SSSA. The results, published today in eLife, provide new and accelerated avenues for developing bionic prostheses, enhanced with sensory feedback. "The stimulation felt almost like what I would feel with my hand," said amputee Dennis Aabo Sørensen about the artificial fingertip connected to his stump. He continues, "I still feel my missing hand, it is always clenched in a fist. I felt the texture sensations at the tip of the index finger of my phantom hand." Sørensen is the first person in the world to recognize texture using a bionic fingertip connected to electrodes that were surgically implanted above his stump. Nerves in Sørensen's arm were wired to an artificial fingertip equipped with sensors. A machine controlled the movement of the fingertip over different pieces of plastic engraved with different patterns, smooth or rough. As the fingertip moved across the textured plastic, the sensors generated an electrical signal. This signal was translated into a series of electrical spikes, imitating the language of the nervous system, then delivered to the nerves. Sørensen could distinguish between rough and smooth surfaces 96percent of the time. In a previous study, Sorensen's implants were connected to a sensory-enhanced prosthetic hand that allowed him to recognize shape and softness. In this new publication about texture in the journal eLife, the bionic fingertip attains a superior level of touch resolution. This same experiment testing coarseness was performed on non-amputees, without the need of surgery. The tactile information was delivered through fine, needles that were temporarily attached to the arm's median nerve through the skin. The non-amputees were able to distinguish roughness in textures 77percent of the time. But does this information about touch from the bionic fingertip really resemble the feeling of touch from a real finger? The scientists tested this by comparing brain-wave activity of the non-amputees, once with the artificial fingertip and then with their own finger. The brain scans collected by an EEG cap on the subject's head revealed that activated regions in the brain were analogous. The research demonstrates that the needles relay the information about texture in much the same way as the implanted electrodes, giving scientists new protocols to accelerate for improving touch resolution in prosthetics. "This study merges fundamental sciences and applied engineering: it provides additional evidence that research in neuroprosthetics can contribute to the neuroscience debate, specifically about the neuronal mechanisms of the human sense of touch," said Calogero Oddo of the BioRobotics Institute of SSSA. "It will also be translated to other applications such as artificial touch in robotics for surgery, rescue, and manufacturing."

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