144 research outputs found

    Cerebellum-based Adaptation for Fine Haptic Control over the Space of Uncertain Surfaces

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    This work aims to augment the capacities for haptic perception in the iCub robot to generate a controller for surface exploration. The main task involves moving the hand over an irregular surface with uncertain slope, by concurrently regulating the pressure of the contact. Providing this ability will enable the autonomous extraction of important haptic features, such as texture and shape. We propose a hand controller whose operational space is defined over the surface of contact. The surface is estimated using a robust probabilistic estimator, which is then used for path planning. The motor commands are generated using a feedback controller, taking advantage of the kinematic information available by proprioception. Finally, the effectiveness of this controller is extended using a cerebellar-like adapter that generates reliable pressure tracking over the finger and results in a trajectory with less vulnerability to perturbations. The results of this work are consistent with insights about the role of the cerebellum on haptic perception in humans

    Embodied hyperacuity from Bayesian perception: Shape and position discrimination with an iCub fingertip sensor

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    Recent advances in modeling animal perception has motivated an approach of Bayesian perception applied to biomimetic robots. This study presents an initial application of Bayesian perception on an iCub fingertip sensor mounted on a dedicated positioning robot. We systematically probed the test system with five cylindrical stimuli offset by a range of positions relative to the fingertip. Testing the real-time speed and accuracy of shape and position discrimination, we achieved sub-millimeter accuracy with just a few taps. This result is apparently the first explicit demonstration of perceptual hyperacuity in robot touch, in that object positions are perceived more accurately than the taxel spacing. We also found substantial performance gains when the fingertip can reposition itself to avoid poor perceptual locations, which indicates that improved robot perception could mimic active perception in animals

    "In a situation of rescuing life"

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    Background: Diabetes mellitus is an emerging public health problem in Tanzania. For the community and the health system to respond adequately to this problem, it is important that we understand the meanings given to its symptoms, and the care-seeking practices of individuals. Methods: To explore collective views on the meanings given to diabetes symptoms, we conducted nine focus group discussions with adult diabetes patients and members of the general community. To gain a better understanding of how the meanings in the community inform the care-seeking practices of individuals, 19 in-depth interviews were conducted with diabetes patients. The data were analyzed using principles of grounded theory and applying cultural schema theory as a deductive framework. Results: In the communities and among the patients, knowledge and awareness of diabetes are limited. Both people with diabetes and community members referred to their prevailing cultural meaning systems and schemas for infectious diseases to interpret and assign meaning to the emerging symptoms. Diabetes patients reported that they had initially used anti-malarial medicines because they believed their symptoms—like headache, fever, and tiredness—were suggestive of malaria. Schemas for body image informed the meaning given to diabetes symptoms similar to those of HIV, like severe weight loss. Confusion among members of the community about the diabetes symptoms instigated tension, causing patients to be mistrusted and stigmatized. The process of meaning-giving and the diagnosis of the diabetes symptoms was challenging for both patients and health care professionals. Diabetes patients reported being initially misdiagnosed and treated for other conditions by medical professionals. The inability to assign meaning to the symptoms and determine their etiologies informed the decision made by some patients to consult traditional healers, and to associate their symptoms with witchcraft causes. Conclusion: The meanings given to diabetes symptoms and the care-seeking practices described in the study are shaped by the prevailing cultural schemas for infectious diseases and their treatments. Efforts to educate people about the symptoms of diabetes and to encourage them to seek out appropriate care should build on the prevailing cultural meaning system and schemas for diseases, health and illness

    A New Silicone Structure for uSkin—A Soft, Distributed, Digital 3-Axis Skin Sensor and Its Integration on the Humanoid Robot iCub

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    Tactile sensing is one important element that can enable robots to interact with an unstructured world. By having tactile perception, a robot can explore its environment by touching objects. Like human skin, a tactile sensor that can provide rich information such as distributed normal and shear forces with high density can help the robot to recognize objects. In previous work, we introduced uSkin, a soft skin with distributed 3-axis force-sensitive elements and a center-to-center distance between the 3-axis load cells of 4.7 mm for the flat version. This letter presents a new structure for the distributed soft force transducer that reduces the crosstalk between the components of the 3-axis force measurements. Three dimensionally (3-D) printing the silicone structure eased the prototype production. However, the 3-D printed material has a higher hysteresis than the previously used Ecoflex. Microcontroller boards originally developed for the skin of iCub were implemented for uSkin, increasing the readout frequency and reducing the space requirements and number of wires. The sensor was installed on iCub and successfully used for shape exploration

    A Pilot Study with a Novel Setup for Collaborative Play of the Humanoid Robot KASPAR with children with autism

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    This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.This article describes a pilot study in which a novel experimental setup, involving an autonomous humanoid robot, KASPAR, participating in a collaborative, dyadic video game, was implemented and tested with children with autism, all of whom had impairments in playing socially and communicating with others. The children alternated between playing the collaborative video game with a neurotypical adult and playing the same game with the humanoid robot, being exposed to each condition twice. The equipment and experimental setup were designed to observe whether the children would engage in more collaborative behaviours while playing the video game and interacting with the adult than performing the same activities with the humanoid robot. The article describes the development of the experimental setup and its first evaluation in a small-scale exploratory pilot study. The purpose of the study was to gain experience with the operational limits of the robot as well as the dyadic video game, to determine what changes should be made to the systems, and to gain experience with analyzing the data from this study in order to conduct a more extensive evaluation in the future. Based on our observations of the childrens’ experiences in playing the cooperative game, we determined that while the children enjoyed both playing the game and interacting with the robot, the game should be made simpler to play as well as more explicitly collaborative in its mechanics. Also, the robot should be more explicit in its speech as well as more structured in its interactions. Results show that the children found the activity to be more entertaining, appeared more engaged in playing, and displayed better collaborative behaviours with their partners (For the purposes of this article, ‘partner’ refers to the human/robotic agent which interacts with the children with autism. We are not using the term’s other meanings that refer to specific relationships or emotional involvement between two individuals.) in the second sessions of playing with human adults than during their first sessions. One way of explaining these findings is that the children’s intermediary play session with the humanoid robot impacted their subsequent play session with the human adult. However, another longer and more thorough study would have to be conducted in order to better re-interpret these findings. Furthermore, although the children with autism were more interested in and entertained by the robotic partner, the children showed more examples of collaborative play and cooperation while playing with the human adult.Peer reviewe

    Embodied language learning and cognitive bootstrapping: methods and design principles

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    Co-development of action, conceptualization and social interaction mutually scaffold and support each other within a virtuous feedback cycle in the development of human language in children. Within this framework, the purpose of this article is to bring together diverse but complementary accounts of research methods that jointly contribute to our understanding of cognitive development and in particular, language acquisition in robots. Thus, we include research pertaining to developmental robotics, cognitive science, psychology, linguistics and neuroscience, as well as practical computer science and engineering. The different studies are not at this stage all connected into a cohesive whole; rather, they are presented to illuminate the need for multiple different approaches that complement each other in the pursuit of understanding cognitive development in robots. Extensive experiments involving the humanoid robot iCub are reported, while human learning relevant to developmental robotics has also contributed useful results. Disparate approaches are brought together via common underlying design principles. Without claiming to model human language acquisition directly, we are nonetheless inspired by analogous development in humans and consequently, our investigations include the parallel co-development of action, conceptualization and social interaction. Though these different approaches need to ultimately be integrated into a coherent, unified body of knowledge, progress is currently also being made by pursuing individual methods

    Antiviral treatment for acute retinal necrosis:A systematic review and meta-analysis

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    Acute retinal necrosis is a progressive intraocular inflammatory syndrome characterized by diffuse necrotizing retinitis that can lead to a poor visual outcome, mainly from retinal detachment. The antiviral treatment approach for acute retinal necrosis varies as there are no established guidelines. We summarize the outcomes of acute retinal necrosis with available antiviral treatments. Electronic searches were conducted in PubMed/MEDLINE, EMBASE, Scopus, and Google Scholar for interventional and observational studies. Meta-analysis was performed to evaluate the pooled proportion of the predefined selected outcomes. This study was registered in PROSPERO (CRD42022320987). Thirty-four studies with a total of 963 participants and 1,090 eyes were included in the final analysis. The estimated varicella-zoster virus and herpes simplex virus polymerase chain reaction-positive cases were 63% (95% CI: 55–71%) and 35% (95% CI: 28–42%), respectively. The 3 main antiviral treatment approaches identified were oral antivirals alone, intravenous antivirals alone, and a combination of systemic (oral or intravenous) and intravitreal antivirals. The overall pooled estimated proportions of visual acuity improvement, recurrence, and retinal detachment were 37% (95% CI: 27–47%), 14% (95% CI: 8–21%), and 43% (95% CI: 38–50%), respectively. Patients treated with systemic and intravitreal antivirals showed a trend towards better visual outcomes than those treated with systemic antivirals (oral or intravenous) alone, even though this analysis was not statistically significant (test for subgroup differences P = 0.83).</p
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