312 research outputs found

    Analysis of simultaneous 3D positioning and attitude estimation of a planar coil using inductive coupling

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    In this paper, simultaneous estimation of 3D position and attitude of a single coil using a set of anchors, with known position and magnetic dipole, is analyzed. Effect of noise and geometric properties of the anchors' constellation is considered. Several parameters are analyzed and discussed, including placement of anchors in a single or in multiple orthogonal planes. It is shown that adding space and orientation diversity anchors may lead to a more robust performance when the mobile node attitude changes in time.Comment: Preprint version. Conference accepted pape

    Accurate Estimation of a Coil Magnetic Dipole Moment

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    In this paper, a technique for accurate estimation of the moment of magnetic dipole is proposed. The achievable accuracy is investigated, as a function of measurement noise affecting estimation of magnetic field cartesian components. The proposed technique is validated both via simulations and experimentally.Comment: Preprin

    Network Methods for Analysis and Design of Resonant Wireless Power Transfer Systems

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    In this chapter we illustrate networks methods for the analysis an design of Wireless Power Transfer (WPT) systems. We begin with an introduction which compares the alternatives available for transfering electromagnetic power. In particular, we illustrate the advantages and disadvantages of the various possibilities: transmission lines, antennas, and mid-range reactive field couplings. Then, in the introduction, we also illustrate practical applications for WPT and discuss relevant papers published so far. In the second section, after introducing a basic structure for realizing WPT (see Fig.1), we discuss the relevant theory for WPT by considering a very simple network which, nevertheless, contains all the relevant phenomenology. We derive formulas for maximizing the efficiency of power transfer and we show the necessity of introducing matching networks. Several possible realizations of matching networks are then illustrated. In the next section we introduce appropriate methods, based on the ABCD matrix, for the narrow-band analysis of WPT systems including matching networks. An example of such a network is reported in Fig. 2. A section will be devoted to the input and output coupling design where we will provide new formulas for the design of the matching networks. In particular we show that, for a given type of resonators with a given quality factor Q and a given value of the coupling between the two resonators, we can find the optimal coupling coefficients which maximize the efficiency. An example of the results achievable when optimizing the input/output coupling is reported in Fig. 3. Having derived a procedure for attaining maximum efficiency, it is also possible to establish the theoretical limits that can be achieved for a given value of coupling and for specified values of the resonators Q. A section will be also devoted to the case of multiple transmitting and multiple receiving resonators. For this arrangement, which has practical relevance and is illustrated in Fig 5, we also introduce a rigorous general network model for its analysis. Several different types of resonators will be investigated and compared. Closed form formulas relevant to the resonators' design will be introduced and also fullwave analysis of resonators well be exploited. Theoretical results will be compared with measured ones and measurement methods will be discussed. One of the problems of WPT, i.e. the frequency shift occurring when resonators are placed at different distances, will be discussed and the solution will be outlined. This is very important in practice because allows to realize systems without the need of complex sources or difficult tracking mechanisms. Finally, we will also illustrate how to analyze, both in frequency and time domain, the network representations used for WPT

    Design and Experimental Characterization of a Combined WPT - PLC System

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    In this contribution, the authors perform the design and show the experimental results relative to a prototype of a combined wireless power transfer (WPT)–power line communications (PLC) system, in which the WPT channel is interfaced to a PLC environment to allow data transfer when the cabled connection is no longer available. The main rationale behind this idea stays in the fact that PLC communication is now a popular choice to enable communications, for instance, in smart grids and in home automation, while WPT devices start to be available in the market (i.e. for mobile phones) and soon they will be a reality also for higher power (i.e. vehicle battery charging). In particular, theoretical insights about the requirements of the system are given; a two coils system has been implemented and a measurement campaign, together with simulations, show that the system is of great potentiality and could be used in applications where both wireless power and data transfer are needed (such as vehicles battery charging), achieving maximum power transfer and good data rate in order to transmit high-speed signals

    An Interactive System for Exhibitions in a Science and Technology Center

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    This paper presents the development of a system for realizing interactive exhibitions in the context of a science and technology center. The core functionality of the system is provided by a positioning subsystem comprised of a fixed infrastructure of transmitters and a sensor worn by a user. The operating principle of the positioning system is based on inductive coupling of resonators. Information about the position of the user is transferred to an information system for processing and displaying. Possible use cases include interactive games, information retrieval interfaces and educational scenarios.Comment: Preprin

    Preliminary Sizing of High-Altitude Airships Featuring Atmospheric Ionic Thrusters: An Initial Feasibility Assessment

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    When it comes to computing the values of variables defining the preliminary sizing of an airship, a few standardized approaches are available in the existing literature. However, when including a disruptive technology in the design is required, sizing procedures need to be amended, so as to be able to deal with the features of any additional novel item. This is the case of atmospheric ionic thrusters, a promising propulsive technology based on electric power, where thrusters feature no moving parts and are relatively cheap to manufacture. The present contribution proposes modifications to an existing airship design technique, originally conceived accounting for standard electro-mechanical thrusters, so as to cope with the specific features of new atmospheric ionic thrusters. After introducing this design procedure in detail, its potential is tested by showing results from feasibility studies on an example airship intended for a high-altitude mission. Concurrently, the so-obtained results allow the demonstration of the sizing features corresponding to the adoption of atmospheric ionic thrusters at the current level of technology, comparing them to what is obtained for the same mission when employing a standard electro-mechanical propulsion system

    A systematic review of the Da Vinci® Single-Port system (DVSP) in the context of colorectal surgery

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    Purpose: The purpose of this study is to review the application of the da Vinci® Single-Port system (DVSP) in colorectal surgery, with a view to assessing its safety and feasibility, and investigating its clinical and oncological outcomes. Methods: A comprehensive search of the scientific literature was conducted across three major databases (PubMed, Web of Science, and Cochrane) up to November 2024. The study was registered in PROSPERO (CRD42024612762) and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included studies pertained to the utilisation of DVSP in the domain of colorectal surgery. Results: Eleven articles were included in the final analysis. No randomized controlled trials were identified. A total of 396 patients (199 men, 197 women) underwent robotic colorectal surgery using the DVSP. Surgical resections were indicated for benign pathology in 56 patients, colon carcinoma in 194 cases, and rectal carcinoma in 146 cases. The median incision length for Uniport placement was 4 cm. The median docking time was 5.96 min (IQR, 9.33 min), and the median console time was 105 min (IQR, 62.51 min). The mean operative time was 186.3 min (IQR, 77.65 min). Intraoperative complications were rare, with only two cases reported (0.47%). Postoperative complications occurred in 12.47% of patients, with ileus being the most common. No patients were readmitted for complications within 30 days. Short-term oncological outcomes seemed promising, with a median of 24.59 lymph nodes retrieved. There were no reported deaths within 30 days. The median follow up time was 11.4 months (IQR, 11.76 months). Conclusion: This study shows that the use of DVSP in colorectal surgery is both feasible and safe. Short-term clinical and oncological outcomes seem promising. However, longer follow-up data and larger patient cohorts are needed to fully assess the long-term efficacy of this novel technique. Prospero registry: Registration number CRD42024612762

    Analysis and outcomes of wrong site thyroid surgery

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    Background: In thyroid surgery, wrong-site surgery (WSS) is considered a rare event and seldom reported in the literature. Case presentation: This report presents 5 WSS cases following thyroid surgery in a 20-year period. We stratified the subtypes of WSS in wrong target, wrong side, wrong procedure and wrong patient. Only planned and elective thyroid surgeries present WSS cases. The interventions were performed in low-volume hospitals, and subsequently, the patients were referred to our centres. Four cases of wrong-target procedures (thymectomies [n = 3] and lymph node excision [n = 1] performed instead of thyroidectomies) and one case of wrong-side procedure were observed in this study. Two wrong target cases resulting additionally in wrong procedure were noted. Wrong patient cases were not detected in the review. Patients experienced benign, malignant, or suspicious pathology and underwent traditional surgery (no endoscopic or robotic surgery). 40% of WSS led to legal action against the surgeon or a monetary settlement. Conclusion: WSS is also observed in thyroid surgery. Considering that reports regarding the serious complications of WSS are not yet available, these complications should be discussed with the surgical community. Etiologic causes, outcomes, preventive strategies of WSS and expert opinion are presented

    On the entanglement entropy of quantum fields in causal sets

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    In order to understand the detailed mechanism by which a fundamental discreteness can provide a finite entanglement entropy, we consider the entanglement entropy of two classes of free massless scalar fields on causal sets that are well approximated by causal diamonds in Minkowski spacetime of dimensions 2,3 and 4. The first class is defined from discretised versions of the continuum retarded Green functions, while the second uses the causal set's retarded nonlocal d'Alembertians parametrised by a length scale lk. In both cases we provide numerical evidence that the area law is recovered when the double-cutoff prescription proposed in arXiv:hep-th/1611.10281 is imposed. We discuss in detail the need for this double cutoff by studying the effect of two cutoffs on the quantum field and, in particular, on the entanglement entropy, in isolation. In so doing, we get a novel interpretation for why these two cutoff are necessary, and the different roles they play in making the entanglement entropy on causal sets finite

    Analisi costo-efficacia del neuromonitoraggio nella chirurgia della tiroide

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    Vi sono prove sempre piø rilevanti circa l’importanza di una piø dettagliata valutazione dei costi delle nuove tecnologie usate in chirurgia. L’impatto innovativo della tecnologia ha il potenziale per ottenere miglioramenti clinici rivoluzionari. Tuttavia, esistono informazioni limitate sul tema costo-efficacia delle nuove strategie chirurgiche usate in chirurgia tiroidea. In questo studio descriviamo le recenti evidenze relative ai metodi di valutazione costo-efficacia delle strutture e delle funzioni per il neuromonitoraggio intraoperatorio (IONM) in chirurgia tiroidea. I nostri risultati suggeriscono che il modello di econo- mia sanitaria, nell’elaborazione della struttura degli studi costo-efficacia relativi al neuromonitoraggio intraoperatorio, si Ł dimostrata realizzabile come metodo per migliorare l’efficacia della ricerca
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