51 research outputs found

    Average reference recording from the vagal nerve reveals an evoked indirect response

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    The vagal nerve conveys information from and to many organs, including the heart. The components of the compound action potentials (CAPs) recorded from the vagal nerve give information about the different fiber types present. In this paper, we show that with the average reference recording method an additional component can be measured. This component is missed when using a tripolar recording method. Recordings were made in anesthetized pigs. Results show that there is an indirect component in the CAP of the cervical vagal nerve. This component comes from the periphery most likely from the heart

    Evaluation of spoken document retrieval for historic speech collections

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    The re-use of spoken word audio collections maintained by audiovisual archives is severely hindered by their generally limited access. The CHoral project, which is part of the CATCH program funded by the Dutch Research Council, aims to provide users of speech archives with online, instead of on-location, access to relevant fragments, instead of full documents. To meet this goal, a spoken document retrieval framework is being developed. In this paper the evaluation efforts undertaken so far to assess and improve various aspects of the framework are presented. These efforts include (i) evaluation of the automatically generated textual representations of the spoken word documents that enable word-based search, (ii) the development of measures to estimate the quality of the textual representations for use in information retrieval, and (iii) studies to establish the potential user groups of the to-be-developed technology, and the first versions of the user interface supporting online access to spoken word collections

    12-segment cuff is superior to ring cuff for sensing and stimulation of cardiac fibers in the vagal trunk

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    Introduction: The vagal nerve is involved in reflexive control of the heart. We would like to sense vagal activity originating from cardiac sensory neurons, and influence cardiac parameters by electrical stimulation of the vagal nerve. The ability of the 12-segment cuff to influence and sense cardiac fibers in the vagal trunk will be compared with the ring cuff. Methods: Experiments were performed in twelve pigs. At the cervical level three cuff electrode configurations were placed on the left vagal nerve for recording and stimulation. The cuffs were 15 mm long and had three circular Pt/Ir electrode contacts with (Fig. 1b). In seven pigs, the third cuff was replaced with a cuff with 12 segments instead of three rings (Fig. 1a). ECG and left ventricular pressure were also recorded. Sensing In twelve pigs sensing was done with a ring cuff and in seven also with a 12-segment cuff. ENG was band-pass filtered at 100-2000Hz, rectified and low-pass filtered at 10Hz, resulting in the envelope of the ENG. Mean activity was removed to obtain only the variations within a cardiac cycle. An ensemble average was determined from 260 cycles of ENG signal, centered on R-tops of the ECG. A signal was identified as cardiac-modulated if the 95%-CI of the ensemble average had a deviation from zero. Stimulation In five pigs the maximal amplitude (300µs, 50Hz) was determined at which, during stimulation with the ring electrode, no coughing occurred. Next in these five pigs, stimulation with this setting was repeated with the ring cuff and the 12-segment cuff. Results: A significantly cardiac-modulated vagal signal was measured in 6/7 pigs with the 12-segment cuff and in 6/12 pigs with the ring cuff. The effect of electrical stimulation on left ventricular pressure was significantly greater when stimulating with the 12-segment cuff than with the ring cuff (p = 0.03). A significant difference was not reached for R-R (p = 0.2) and left ventricular contractility (p = 0.07). Conclusion: The 12-segment cuff seems superior to the ring cuff, considering selective sensing and stimulation of the cardiac fibers in the cervical vagal trunk

    An evoked indirect response in the cervical vagal nerve

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    The response of fibers in the vagal nerve, evoked by electrical stimulation, has been studied in both animals and humans. These compound action potentials (CAPs) consist of components coming from thick, myelinated fibers to thin, unmyelinated fibers. In our study, the possibility is addressed of an indirect component in the CAP which is involved in reflexive control. By using multiple, consecutive electrode sites along the cervical vagal nerve, both the direction and the velocity along the nerve of the CAPs can be analyzed. This information can be used to distinguish direct from indirect components. In this way an indirect component was revealed

    Does your robot know? Enhancing children's information retrieval through spoken conversation with responsible robots

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    In this paper, we identify challenges in children's current information retrieval process, and propose conversational robots as an opportunity to ease this process in a responsible way. Tools children currently use in this process, such as search engines on a computer or voice agents, do not always meet their specific needs. The conversational robot we propose maintains context, asks clarifying questions, and gives suggestions in order to better meet children's needs. Since children are often too trusting of robots, we propose to have the robot measure, monitor and adapt to the trust the child has in the robot. This way, we hope to induce a critical attitude with the children during their information retrieval process.Comment: IR4Children'21 workshop at SIGIR 2021 - http://www.fab4.science/IR4C

    AXES at TRECVid 2011

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    Abstract The AXES project participated in the interactive known-item search task (KIS) and the interactive instance search task (INS) for TRECVid 2011. We used the same system architecture and a nearly identical user interface for both the KIS and INS tasks. Both systems made use of text search on ASR, visual concept detectors, and visual similarity search. The user experiments were carried out with media professionals and media students at the Netherlands Institute for Sound and Vision, with media professionals performing the KIS task and media students participating in the INS task. This paper describes the results and findings of our experiments
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