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- Carrozza, M, et al.
(författare)
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Design of a cybernetic hand for perception and action.
- 2006
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Ingår i: Biol Cybern. - : Springer Science and Business Media LLC. - 0340-1200. ; 95:6, s. 629-644
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Tidskriftsartikel (refereegranskat)abstract
- Strong motivation for developing new prosthetic hand devices is provided by the fact that low functionality and controllability-in addition to poor cosmetic appearance-are the most important reasons why amputees do not regularly use their prosthetic hands. This paper presents the design of the CyberHand, a cybernetic anthropomorphic hand intended to provide amputees with functional hand replacement. Its design was bio-inspired in terms of its modular architecture, its physical appearance, kinematics, sensorization, and actuation, and its multilevel control system. Its underactuated mechanisms allow separate control of each digit as well as thumb-finger opposition and, accordingly, can generate a multitude of grasps. Its sensory system was designed to provide proprioceptive information as well as to emulate fundamental functional properties of human tactile mechanoreceptors of specific importance for grasp-and-hold tasks. The CyberHand control system presumes just a few efferent and afferent channels and was divided in two main layers: a high-level control that interprets the user's intention (grasp selection and required force level) and can provide pertinent sensory feedback and a low-level control responsible for actuating specific grasps and applying the desired total force by taking advantage of the intelligent mechanics. The grasps made available by the high-level controller include those fundamental for activities of daily living: cylindrical, spherical, tridigital (tripod), and lateral grasps. The modular and flexible design of the CyberHand makes it suitable for incremental development of sensorization, interfacing, and control strategies and, as such, it will be a useful tool not only for clinical research but also for addressing neuroscientific hypotheses regarding sensorimotor control.
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- Edin, Benoni, et al.
(författare)
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A Bio-inspired approach for the design and characterization of a tactile sensory system for a cybernetic prosthetic hand
- 2006
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Ingår i: Robotics and Automation: Proceedings of the 2006 IEEE International Conference on Robotics and Automation. - 1050-4729. ; , s. 1354-1358
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Tidskriftsartikel (refereegranskat)abstract
- REcent research in prosthetic hands aims at developing innovative cybernetic systems able to allow users to feel an artificial hand as part of their bodies by providing the tactile sensation of a natural hand. Such prostheses must be endowed with artificial proprioceptive and exteroceptive sensory systems as well as appropriate neural interfaces able to exchange sensorymotor signals between the body and the nervous system of an amputee. Based on consideration of available neurophysiological and behavioral data in humans and on the specific sensory needs to control a prototypical grasp-and-lift task, two kinds of sensors were developed: on-off contact sensor arrays and triaxial force sensors. Both sensor types were characterized and compared with their biological counterparts. Their ability to convey critical information durin a lift task was evaluated with the sensors integrated in a biomechatronic cybernetic hand.
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- Edin, Benoni B, et al.
(författare)
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Bio-inspired sensorization of a biomechatronic robot hand for the grasp-and-lift task.
- 2008
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Ingår i: Brain Research Bulletin. - : Elsevier BV. - 0361-9230 .- 1873-2747. ; 75:6, s. 785-95
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Tidskriftsartikel (refereegranskat)abstract
- It has been concluded from numerous neurophysiological studies that humans rely on detecting discrete mechanical events that occur when grasping, lifting and replacing an object, i.e., during a prototypical manipulation task. Such events represent transitions between phases of the evolving manipulation task such as object contact, lift-off, etc., and appear to provide critical information required for the sequential control of the task as well as for corrections and parameterization of the task. We have sensorized a biomechatronic anthropomorphic hand with the goal to detect such mechanical transients. The developed sensors were designed to specifically provide the information about task-relevant discrete events rather than to mimic their biological counterparts. To accomplish this we have developed (1) a contact sensor that can be applied to the surface of the robotic fingers and that show a sensitivity to indentation and a spatial resolution comparable to that of the human glabrous skin, and (2) a sensitive low-noise three-axial force sensor that was embedded in the robotic fingertips and showed a frequency response covering the range observed in biological tactile sensors. We describe the design and fabrication of these sensors, their sensory properties and show representative recordings from the sensors during grasp-and-lift tasks. We show how the combined use of the two sensors is able to provide information about crucial mechanical events during such tasks. We discuss the importance of the sensorized hand as a test bed for low-level grasp controllers and for the development of functional sensory feedback from prosthetic devices.
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- Panarese, Alessandro, et al.
(författare)
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Humans can integrate force feedback to toes in their sensorimotor control of a robotic hand
- 2009
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Ingår i: IEEE transactions on neural systems and rehabilitation engineering. - 1534-4320 .- 1558-0210. ; 17:6, s. 560-567
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Tidskriftsartikel (refereegranskat)abstract
- Tactile sensory feedback is essential for dexterous object manipulation. Users of hand myoelectric prostheses without tactile feedback must depend essentially on vision to control their device. Indeed, improved tactile feedback is one of their main priorities. Previous research has provided evidence that conveying tactile feedback can improve prostheses control, although additional effort is required to solve problems related to pattern recognition learning, unpleasant sensations, sensory adaptation, and low spatiotemporal resolution. Still, these studies have mainly focused on providing stimulation to hairy skin regions close to the amputation site, i.e., usually to the upper arm. Here, we explored the possibility to provide tactile feedback to the glabrous skin of toes, which have mechanical and neurophysiological properties similar to the fingertips. We explored this paradigm in a grasp-and-lift task, in which healthy participants controlled two opposing digits of a robotic hand by changing the spacing of their index finger and thumb. The normal forces applied by the robotic fingertips to a test object were fed back to the right big and second toe. We show that within a few lifting trials, all the participants incorporated the force feedback received by the foot in their sensorimotor control of the robotic hand.
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- Thesleff, P, et al.
(författare)
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A mixed endocrine adrenal tumour causing steatorrhoea
- 1987
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Ingår i: Gut. - : BMJ. - 0017-5749. ; 28:10, s. 301-1298
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Tidskriftsartikel (refereegranskat)abstract
- A 60 year old man developed steatorrhoea, weight loss, mild diabetes mellitus, labile hypertension and limb cramps. Raised plasma concentrations of catecholamines, particularly noradrenaline and a computed tomography-scan showing an adrenal tumour strongly suggested a pheochromocytoma. Adrenoreceptor blockade reversed the symptoms, decreased faecal fat, and increased duodenal trypsin to normal concentrations. After adrenalectomy the patient was asymptomatic and there was no steatorrhoea. The blood glucose concentrations became normal. Immunocytochemistry revealed the tumour cells to store large amounts of enkephalin and somatostatin reactive material and moderate amounts of immunoreactive beta-endorphin and dynorphin.
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