Beam Steering with Segmented Annular Arrays

Two-dimensional (2-D) arrays of squared matrix have maximum periodicity in their main directions; consequently, they require half wavelength (λ/2), interelement spacing to avoid grating lobes. This condition gives rise to well-known problems derived from the huge number of array elements and from their small size. In contrast, 2-D arrays with curvilinear configuration produce lower grating lobes and, therefore, allow the element size to be increased beyond λ/2. Using larger elements, these arrays have the advantage of reducing the number of elements and of increasing the signal-to-noise ratio (SNR). In this paper, the beamforming properties of segmented annular phased arrays are theoretically analyzed and compared with the equivalent squared matrix array. In the first part, point-like elements are considered in order to facilitate the field analysis with respect to the array structure. Afterward, the effect of the element size on the steered beam properties also is presented. In the examples, it is shown that the segmented annular array has notably lower grating lobes than the equivalent squared matrix array and that it is possible to design segmented annular arrays with interelement distance higher than λ whose beam characteristics are perfectly valid for volumetric imaging applications.This paper received the support of the Education and Science Ministry of Spain under its DPI2002-01583, DPI2004-06470, and DPI2004-06756 projects.Peer reviewe

Program evaluation dashboard design and development for Missouri telehealth network show-me echo program

Background: The Show-Me ECHO Program is a state funded telehealth project, established in 2014, that connects interdisciplinary teams of experts with rural and isolated primary care providers (PCPs) and other professionals using videoconferencing and interactive case-based learning in an effort to develop advanced skills, best practices and ultimately improve patient care access, quality, and efficiency. Since inception, the Show-Me ECHO program has experienced rapid growth and expansion to over 40 ECHO topics, impacting all 114 Missouri Counties and over 2,300 health/community organizations. The exponential growth experienced by the ECHO model highlights a crucial need for adept program evaluation, reporting tools and resources which will facilitate the process of systematically examining the implementation, quality, impact, and value of the program. Objective: The objective of this project is to design and build data dashboards that support a macro-evaluation and management of Missouri Telehealth Network's Show-Me ECHO program and contributes to program improvement activities. Methods: A stakeholder identification and needs analysis was completed to ensure comprehensive measurement of program performance metrics. Show-Me ECHO program administrative data, clinic information, attendance records for participants and facilitators, case presentation metrics, didactic presentations, and more were extracted from MTN data repositories for the 2014-2021 period and analyzed for dashboard development. Data cleaning and preprocessing was conducted in a combination of Excel, Python and Tableau. The dashboards and other data visualization metrics were created in Tableau. Results: Data extraction generated a total of 70,910 observations across three reports ('Clinic Data', 'Didactic Presentation Data' and 'Patient Presentation Data'). Three preliminary dashboards -- "Show-Me ECHO Project Reach and Attendance" "Show-Me ECHO Project Overview" and "ECHO Clinic Performance Report" were established to provide Missouri Telehealth Network (MTN) teams and stakeholders detailed insight into growth and performance of the Show-Me ECHO project and support development and management of action plans. Conclusions: The constructed MTN Dashboards support organization efforts to establish a single unified approach to monitor program progress, identify and prioritize efforts and resource allocation, identify specific Missouri counties that may benefit from interventions and ECHO clinic expansions, and provide appropriate performance metrics that can be shared with both decision makers and relevant stakeholders. Future considerations for dashboard expansion include incorporating PCP self-efficacy and knowledge surveys and Claims data analysis to enable further tracking of Provider and Patient outcomes. A feasibility assessment of the implementation of dashboards at other superhubs for benchmarking and program outcome comparison studies should also be considered.Includes bibliographical references

Research progress on geosynchronous synthetic aperture radar

Based on its ability to obtain two-dimensional (2D) high-resolution images in all-time and all-weather conditions, spaceborne synthetic aperture radar (SAR) has become an important remote sensing technique and the study of such systems has entered a period of vigorous development. Advanced imaging modes such as radar interferometry, tomography, and multi-static imaging, have been demonstrated. However, current in-orbit spaceborne SARs, which all operate in low Earth orbits, have relatively long revisit times ranging from several days to dozens of days, restricting their temporal sampling rate. Geosynchronous SAR (GEO SAR) is an active research area because it provides significant new capability, especially its much-improved temporal sampling. This paper reviews the research progress of GEO SAR technologies in detail. Two typical orbit schemes are presented, followed by the corresponding key issues, including system design, echo focusing, main disturbance factors, repeat-track interferometry, etc, inherent to these schemes. Both analysis and solution research of the above key issues are described. GEO SAR concepts involving multiple platforms are described, including the GEO SAR constellation, GEO-LEO/airborne/unmanned aerial vehicle bistatic SAR, and formation flying GEO SAR (FF-GEO SAR). Due to the high potential of FF-GEO SAR for three-dimensional (3D) deformation retrieval and coherence-based SAR tomography (TomoSAR), we have recently carried out some research related to FF-GEO SAR. This research, which is also discussed in this paper, includes developing a formation design method and an improved TomoSAR processing algorithm. It is found that GEO SAR will continue to be an active topic in the aspect of data processing and multi-platform concept in the near future

Monumentalizing Rituals of the Palestinian Diaspora

Displaced Palestinians have historically sought to preserve their Palestinian memories and identities in order to remain connected to their lost homeland. Despite the importance of memory for them, and their history of suffering and exile, there have not been any significant monuments designed to preserve their collective memory. This thesis considers the adaptation of a traditional monument by redesigning it to the specificity of the Palestinian diaspora. In doing so it proposes the monumentalizing of four Palestinian rituals to add significance, meaning and permanence to them. The four rituals are making maamoul, applying orange and mashmoom perfume oil to hair, pouring Palestinian olive oil and dispersing sage tea leaves within a family. The key attributes captured, conveyed and explored within these rituals are the role of the matriarch and the sensory olfactory system that elicits memories and narratives of Palestine

The Harvesting of the Energy from the Piezo-Electric Materials Using Sounds

This work deals with research and development of ambient energy harnessing technology from mechanical vibration.To harness mechanical vibration from ambient energy a piezoelectricmaterial is used.To create a vibration, sound is produced from a portable speaker, The sound produced from portable speaker is induced on piezoelectric material ,The frequency of the sound is controlled by laptop by playing a sine wave frequency and it was played at constant volume which was measured by using a microphone, then the series of experiment was conducted on the piezoelectric transducer. To harness the energy from the piezoelectric transducer diode bridge circuit was used, And for measuring the output of the circuit voltmeter was used. The experiment was conducted in five case studies, i.e. by moving the position of a piezoelectric transducer, changing the angle of a piezoelectric transducer, enclosing the setup, changing the area of the enclosure and Connecting two piezoelectric transducers in parallel.This work deals with research and development of ambient energy harnessing technology from mechanical vibration.To harness mechanical vibration from ambient energy a piezoelectricmaterial is used.To create a vibration, sound is produced from a portable speaker, The sound produced from portable speaker is induced on piezoelectric material ,The frequency of the sound is controlled by laptop by playing a sine wave frequency and it was played at constant volume which was measured by using a microphone, then the series of experiment was conducted on the piezoelectric transducer. To harness the energy from the piezoelectric transducer diode bridge circuit was used, And for measuring the output of the circuit voltmeter was used. The experiment was conducted in five case studies, i.e. by moving the position of a piezoelectric transducer, changing the angle of a piezoelectric transducer, enclosing the setup, changing the area of the enclosure and Connecting two piezoelectric transducers in parallel

Understanding Los Angeles street art: Between social mobilization and urbanites awareness

Από την προσάρτηση της Πόλης των Αγγέλων στις ΗΠΑ (1848), οι υπεύθυνοι δημοσίων σχέσεων της πόλης, γνωστοί ως boosters/προωθητές, σχεδίασαν μια φαντασιακή εκδοχή αυτού του νεοαποκτηθέντος  χώρου που επηρεάζει την ίδια του την ταυτότητά του μέχρι σήμερα. Το ονειρεμένο Λος Άντζελες δημιουργήθηκε για να πουλήσει ένα ιδανικό και μαζί με αυτό βεβαίως και κομμάτια γης. Αυτός ο μηχανισμός υποστηρίχθηκε από μια νέο-φιλελεύθερη διακυβέρνηση που επέλεξε να αφήσει στο Εμπορικό Επιμελητήριο της πόλης να αποφασίσει ποιο δρόμο θα ακολουθήσει. Το άρθρο αυτό εξετάζει την επιρροή που είχε ο φαντασιακός  σχεδιασμός του Λος Άντζελες στην κατοίκηση του αστικού χώρου και πώς αυτή η φαντασιακή διάσταση της πόλης έγινε ο ακρογωνιαίος λίθος της ασυναγώνιστης ανάπτυξής της. Διερευνάται παράλληλα το πώς η κοινωνική κινητοποίηση προσαρμόζεται σε αυτόν τον νέο αστικό σχεδιασμό που ταλαντεύεται ανάμεσα σε δύο είδη κανόνων, έναν πρώτο που βασίζεται σε ουτοπίες και ένα δεύτερο που φτιάχνεται από ασυμβίβαστες αλήθειες. Οι Αντζελίνος πειραματίζονται με νέους τρόπους προκειμένου  να ανακτήσουν την ανθρωπινότητα της περιοχής που μοιάζει να αντιλαμβάνεται του κατοίκους της κυρίως ως κοινωνικο-οικονομικά στατιστικά δεδομένα. Η κοινωνική κινητοποίηση στο Λος Άντζελες αναγκάζεται να προσμετρήσει αυτήν την συνήθεια μυθοπλασίας και τη μυθοπλαστική διαδικασία της πόλης προκειμένου να επινοήσει τρόπους διαφυγής από αυτές και να υπάρξει σε μια πραγματικότητα καθημερινότητας έξω, την οποία ωστόσο αυτές ανταγωνίζονται. Μία ειδικά πρακτική που ορατότητα από τις αρχές του 21ου αιώνα έχει επωφεληθεί και αποκτήσει είναι το να κάνεις τέχνη του δρόμου. Αυτή η έντονα οπτική και ορατή πρακτική έγινε για το ΛΑ κοινωνικός θεσμός που τείνει να επανοηματοδοτήσει κοινωνικές αξίες και πρακτικές κοινωνικότητας.Ever since Los Angeles was annexed to the rest of the United States in 1848, the city’s publicists, better known as boosters, have fashioned a fantasized version of this newly acquired space that has impacted its very identity up until today. The dreamed Los Angeles was created in order to sell an ideal and, off course, land parcels. This mechanism was supported by a local neo-liberal government that chose to let the city’s Chamber of Commerce decide which course to take. This article aims at showing the impact that the dreamed Los Angeles had on the effective urban area and its inhabitants, and how this fantasized dimension of the city became the cornerstone that enabled its unparalleled development.It also seeks out to investigate how social mobilization is adjusting to this new urban order that oscillates constantly between two sets of rules, one made of illusions, the other made of uncompromising truths. Angelenos are thus exploring new ways to regain some humanness in a territory that seems to apprehend its inhabitants merely as socio-economic statistics. Social mobilization in Los Angeles is thus forced to take into account this fictionalized habit and fictionalizing process of the city to produce new ways of escaping it in order to exist outside of it, in a reality that concurs with their everyday Los Angeles. One particular practice that has gradually benefited from more and more visibility in the city since the beginning of the xxistcentury, is doing just that: Street Art.  This highly visual and visible practice is becoming, in Los Angeles, a social enactment that tends to reconceptualize social values as well as socializing practices

Transcranial Ultrasound Holograms for the Blood-Brain Barrier Opening

[ES] El tratamiento de enfermedades neurológicas está muy limitado por la ineficiente penetración de los fármacos en el tejido cerebral dañado debido a la barrera hematoencefálica (BHE), lo que imposibilita mejorar la salud del paciente. La BHE es un mecanismo de protección natural para evitar la difusión de agentes potencialmente peligrosas para el sistema nervioso central. No obstante, la BHE se puede inhibir mediante ultrasonidos focalizados e inyección de microburbujas de forma segura, localizada y transitoria, una tecnología empleada mundialmente. La principal ventaja es su carácter no invasivo, siendo así muy atractiva y cómoda para el paciente. Normalmente, la zona cerebral enferma se trata en su parte central empleando un único foco. Sin embargo, enfermedades como el Alzheimer o el Parkinson requieren un tratamiento sobre estructuras de geometría compleja y tamaño elevado, situadas en ambos hemisferios cerebrales. Por tanto, la tecnología actual está muy limitada al no cumplir dichos requisitos. Esta tesis doctoral tiene como objetivo el desarrollo de una técnica novedosa, basada en hologramas acústicos, para resolver las limitaciones presentes en los tratamientos neurológicos empleando ultrasonidos. Se estudian las lentes acústicas holográficas impresas en 3D, que acopladas a un transductor mono-elemento, permiten el control preciso del frente de onda ultrasónico tanto para (1) compensar las distorsiones que sufre el haz hasta alcanzar el cerebro, como (2) focalizarlo simultáneamente en regiones múltiples y de geometría compleja o formando de vórtices acústicos, proporcionando así efectividad en tiempo y coste. Por ello, la investigación desarrollada en esta tesis abre un camino prometedor en el campo de la biomedicina que permitirá mejorar los tratamientos neurológicos, además de aplicaciones en neuroestimulación o ablación térmica del tejido.[CA] El tractament de malalties neurològiques està molt limitat per la ineficient penetració del fàrmac en el teixit cerebral danyat a causa de la barrera hematoencefàlica (BHE), i així no és possible una millora de salut del pacient. La BHE és un mecanisme de protecció natural per a evitar la difusió d'agents potencialment perillosos per al Sistema Nervios Central. No obstant això, aquesta barrera es pot inhibir mitjancant una tecnologia emprada mundialment basada en ultrasons focalitzats i injeccio de microbombolles. El principal avantatge és el seu caràcter no invasiu, sent així molt atractiva i còmoda per al pacient, i permet obrir la BHE de manera segura, localitzada i transitòria. Normalment, la zona cerebral malalta es tracta en la seua part central, emprant un unic focus. No obstant això, malalties com l'Alzheimer o el Parkinson requereixen un tractament al llarg d'estructures de geometria complexa i grandària elevada, situades en tots dos hemisferis cerebrals. Per tant, la tecnologia actual està fortament limitada al no complir amb aquests requeriments. Aquesta tesi doctoral està enfocada a investigar i desenvolupar una tècnica nova, basada en hologrames acústics, per a solucionar les limitacions presents en els tractaments neurològics. Una lent acústica holograca de baix cost impresa en 3D acoblada a un transductor d'element simple permet el control precs del front d'ona ultrasònic punt per a (1) compensar les distorsions que pateix el feix en el seu camí cap al cervell, i (2) focalització simultània del feix en regions multiples i de geometria complexa, proporcionant aix un tractament efectiu en temps i cost. Per això, la investigació desenvolupada en aquesta tesi demostra la possibilitat de realitzar qualsevol tractament neurològic, a més d'aplicacions en la neuroestimulació o l'ablació tèrmica dins del camp biomèdic.[EN] Treatments for neurological diseases are strongly limited by the inefficient penetration of therapeutic drugs into the diseased brain due to the blood-brain barrier (BBB), and therefore no health improvement can be achieved. In fact, the BBB is a protection mechanism of the human body to avoid the diffusion of potentially dangerous agents into the central nervous system. Nevertheless, this barrier can be successfully inhibited by using a worldwide spread technology based on microbubble-enhanced focused ultrasound. Its main advantage is its non-invasive nature, thus defining a patient-friendly clinical procedure that allows to disrupt the BBB in a safe, local and transient manner. Conventionally, the diseased brain structure has been targeted in its center, with a single focus. However, Alzheimer's or Parkinson's Diseases do require that ultrasound is delivered to entire, complex-geometry and large-volume structures located at both hemispheres of the brain. Therefore, current technology presents several limitations as it does not fulfill these requirements. This doctoral thesis aims to develop a novel technique based on using focused ultrasound acoustic holograms to solve the existing limitations to treat neurological diseases. In this dissertation, we study 3D-printed holographic acoustic lenses coupled to a single-element transducer that allow to accurately control the acoustic wavefront to both (1) compensate distortions suffered by the beam in its path to the brain, and (2) simultaneous focusing in multiple and complex-geometry structures or acoustic vortex generation, providing a time- and cost- efficient procedure. Therefore, the research carried out throughout this thesis opens a promising path in the biomedical field to improve the treatment for neurological diseases, neurostimulation or tissue ablation applications.Acknowledgments to the Spanish institution Generalitat Valenciana, which funding grant allowed me to develop this doctoral thesis, and as well funded my research stay at Columbia University. The development of the entire thesis was supported through grant Nª. ACIF/2017/045. Particularly, the research carried out in Chapter 3 and Chapter 4 was possible thanks to and supported through grant BEFPI/2019/075. Action co-financied by the Agència Valenciana de la Innovació through grant INNVAL10/19/016 and by the European Union through the Programa Operativo del Fondo Europeo de Desarrollo Regional (FEDER) of the Comunitat Valenciana 2014-2020 (IDIFEDER/2018/022).Jiménez Gambín, S. (2021). Transcranial Ultrasound Holograms for the Blood-Brain Barrier Opening [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/171373TESI