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Wireless Magnetoelectric Communication for Bioelectronics
No full textEMBARGO NOTE: This item is embargoed until 2025-05-01Implantable bioelectronics hold great potential to improve the diagnosis and treatment of myriad chronic health conditions. Wireless bioelectronic implants that continuously monitor the patient’s physiological state and transmit these data in real-time without tethers would improve diagnosis and facilitate adaptive therapeutic interventions. However, existing wireless communication modalities, such as Bluetooth, radio frequency, and ultrasound, have performance trade-offs regarding implant size, misalignment tolerance, power consumption, and operational distance.
In this dissertation, I present the first wireless backscatter magnetoelectric communication system that features a miniaturized size, ultra-low power consumption, and deep operational distance with high misalignment tolerance. The system leverages two fundamental characteristics of the magnetoelectric transducers. Firstly, magnetoelectric materials generate a backscattered magnetic field when excited by an external field; we exploit these fields as a carrier signal. The magnetoelectric implant consumes negligible power for carrier generation since the external field that induces this signal is generated outside the body. Secondly, the characteristics of the backscattered field can be modulated by an external electric load; thus, we can use load modulation for digital data encoding.
This design enables continuous, real-time data transmission from a mm-sized magnetoelectric.
bioimplant to a custom-designed external transceiver. Our benchtop testing shows that the system can support an operational range within 55 mm while maintaining a bit error rate (BER) of less than 1E-6. Furthermore, the system is robust to translational misalignment; the system performance is maintained with a misalignment of more than 10 mm.
To validate the system reliability in real-life applications and facilitate the clinical
translation of this technology, we tested the system operation in a porcine model. We have shown two demonstrations of in-vivo studies: wireless monitoring of stimulation electrode impedance for cortical brain implants and real-time remote monitoring of electrical intracardiac signals for cardiac implants. The proposed technology could
enable the design of next-generation bioelectronics that feature real-time physiology monitoring for more precise diagnosis, as well as closed-loop systems for personalized therapies
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Wireless Magnetoelectric Communication for Bioelectronics
No full textImplantable bioelectronics hold great potential to improve the diagnosis and treatment of myriad chronic health conditions. Wireless bioelectronic implants that continuously monitor the patient’s physiological state and transmit these data in real-time without tethers would improve diagnosis and facilitate adaptive therapeutic interventions. However, existing wireless communication modalities, such as Bluetooth, radio frequency, and ultrasound, have performance trade-offs regarding implant size, misalignment tolerance, power consumption, and operational distance.
In this dissertation, I present the first wireless backscatter magnetoelectric communication system that features a miniaturized size, ultra-low power consumption, and deep operational distance with high misalignment tolerance. The system leverages two fundamental characteristics of the magnetoelectric transducers. Firstly, magnetoelectric materials generate a backscattered magnetic field when excited by an external field; we exploit these fields as a carrier signal. The magnetoelectric implant consumes negligible power for carrier generation since the external field that induces this signal is generated outside the body. Secondly, the characteristics of the backscattered field can be modulated by an external electric load; thus, we can use load modulation for digital data encoding.
This design enables continuous, real-time data transmission from a mm-sized magnetoelectric.
bioimplant to a custom-designed external transceiver. Our benchtop testing shows that the system can support an operational range within 55 mm while maintaining a bit error rate (BER) of less than 1E-6. Furthermore, the system is robust to translational misalignment; the system performance is maintained with a misalignment of more than 10 mm.
To validate the system reliability in real-life applications and facilitate the clinical
translation of this technology, we tested the system operation in a porcine model. We have shown two demonstrations of in-vivo studies: wireless monitoring of stimulation electrode impedance for cortical brain implants and real-time remote monitoring of electrical intracardiac signals for cardiac implants. The proposed technology could
enable the design of next-generation bioelectronics that feature real-time physiology monitoring for more precise diagnosis, as well as closed-loop systems for personalized therapies
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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