Colorful textile antennas integrated into embroidered logos

We present a new methodology to create colorful textile antennas that can be embroidered within logos or other aesthetic shapes. Conductive threads (e-Threads) have already been used in former embroidery unicolor approaches as attributed to the corresponding conductive material, viz. silver or copper. But so far, they have not been adapted to \u27print\u27 colorful textile antennas. For the first time, we propose an approach to create colorful electronic textile shapes. In brief, the embroidery process uses an e-Thread in the bobbin case of the sewing machine to embroider the antenna on the back side of the garment. Concurrently, a colorful assistant yarn is threaded through the embroidery needle of the embroidery machine and used to secure or \u27couch\u27 the e-Threads onto the fabric. In doing so, a colorful shape is generated on the front side of the garment. The proposed antennas can be unobtrusively integrated into clothing or other accessories for a wide range of applications (e.g., wireless communications, Radio Frequency IDentification, sensing)

Miniature implantable antennas for biomedical telemetry: from simulation to realization

WOS:000310154700019 (Nº de Acesso Web of Science)“Prémio Científico ISCTE-IUL 2013”We address numerical versus experimental design and testing of miniature implantable antennas for biomedical telemetry in the medical implant communications service band (402-405 MHz). A model of a novel miniature antenna is initially proposed for skin implantation, which includes varying parameters to deal with fabrication-specific details. An iterative design-and-testing methodology is further suggested to determine the parameter values that minimize deviations between numerical and experimental results. To assist in vitro testing, a low-cost technique is proposed for reliably measuring the electric properties of liquids without requiring commercial equipment. Validation is performed within a specific prototype fabrication/testing approach for miniature antennas. To speed up design while providing an antenna for generic skin implantation, investigations are performed inside a canonical skin-tissue model. Resonance, radiation, and safety performance of the proposed antenna is finally evaluated inside an anatomical head model. This study provides valuable insight into the design of implantable antennas, assessing the significance of fabrication-specific details in numerical simulations and uncertainties in experimental testing for miniature structures. The proposed methodology can be applied to optimize antennas for several fabrication/testing approaches and biotelemetry applications

Dual-band implantable antennas for medical telemetry: a fast design methodology and validation for intra-cranial pressure monitoring

WOS:000323538100010 (Nº de Acesso Web of Science)In this study, we suggest and experimentally validate a methodology for fast and optimized design of dual-band implantable antennas for medical telemetry (MICS, 402-405 MHz, and ISM, 2400-2480 MHz). The methodology aims to adjust the design of a parametric dual-band antenna model towards optimally satisfying the requirements imposed by the antenna-fabrication procedure and medical application in hand. Design is performed in a systematic, fast, and accurate way. To demonstrate its effectiveness, the proposed methodology is applied to optimize the parametric antenna model for intra-cranial pressure (ICP) monitoring given a specific antenna-fabrication procedure. For validation purposes, a prototype of the optimized antenna is fabricated and experimentally tested. The proposed antenna is further evaluated within a 13-tissue anatomical head model in terms of resonance, radiation, and safety performance for ICP monitoring. Extensive parametric studies of the optimized antenna are, finally, performed. Feasibility of the proposed parametric antenna model to be optimally re-adjusted for various scenarios is demonstrated, and generic guidelines are provided for implantable antenna design. Dual-band operation is targeted to ensure energy autonomy for the implant. Finite Element (FE) and Finite Difference Time Domain (FDTD) simulations are carried out in homogeneous rectangular and anatomical head tissue models, respectively

IEEE Access Special Section: Antenna and Propagation for 5G and Beyond

5G is not just the next evolution of 4G technology; it is a paradigm shift. “5G and beyond” will enable bandwidth in excess of 100s of Mb/s with a latency of less than 1 ms, in addition to providing connectivity to billions of devices. The verticals of 5G and beyond are not limited to smart transportation, industrial IoT, eHealth, smart cities, and entertainment services, transforming the way humanity lives, works, and engages with its environment

Design of implantable antennas for wireless medical telemetry applications

Implantable medical devices (IMDs) are nowadays attracting significant scientific interest for a number of prevention, diagnosis, and therapy applications. One of their basic characteristics is their ability to communicate with exterior monitoring/control devices, also known as medical telemetry. The aim of the present PhD Thesis is to address the major challenges related to the numerical and experimental investigation of implantable antennas, or, equivalently, antennas which are integrated into IMDs for wireless medical telemetry purposes.Initially, the potential of several miniaturization techniques is studied for implantable antennas, and, based on a novel parametric model of a patch implantable antenna, five new antennas are designed and compared in terms of performance for telemetry in the Medical Implant Communications Service (MICS) band (402–405 MHz). Emphasis is given on quantifying the degradation of the radiation and safety performance of implantable antennas as a function of their occupied physical volume. Given the results, two novel implantable antennas are designed, which occupy relatively enhanced volume in favor of improved performance: a wide–bandwidth antenna, and a dual–band antenna.Four novel methodologies are further developed and evaluated for implantable antenna design inside specific implantation scenarios (implantation sites inside the human body). The goal is to accelerate implantable antenna design while optimizing the achieved resonance performance. Evaluation and comparison of the proposed methodologies is numerically carried out within the framework of designing novel microstrip antennas for implantation inside the skin tissue of the human head, and medical telemetry in the MICS band.A parametric study is then carried out regarding the resonance, radiation, and safety performance of implantable antennas, with respect to: (a) the medical application under consideration (implantation site of the antenna), (b) inter–subject variability (anatomical structure and electric properties of biological tissues), and (c) the frequency at which medical telemetry takes place. The aim is to study the interoperability of implantable antennas, and evaluate their performance as a function of operation frequency.Furthermore, issues related to fabrication and experimental testing of implantable antennas are investigated. Novel recipes are proposed for liquid and semi–solid phantoms which emulate the skin and muscle tissues in the MICS band, and a novel design–and–testing methodology for implantable antennas is developed, which aims to minimize deviations between numerical and experimental results. The methodology is evaluated within the framework of fabricating two novel MICS implantable antennas and experimentally testing them inside phantoms. The potential of the fabricated antennas is, further, studied through implantation and in–vivo measurements in rats, following the development of a suitable experimental protocol. The Thesis concludes with numerical and experimental investigations of the wireless telemetry link between implantable and exterior antennas. The far–field link is modeled, and its performance is evaluated for several operation frequencies and propagation scenarios. Two exterior antennas are further designed, fabricated, and measured for use in wireless MICS telemetry links: a monopole antenna, and a novel wearable dual–band patch antenna. Finally, numerical and experimental studies are carried out regarding the transmission coefficient and maximum communication range between implantable and exterior antennas operating stand–alone or integrated into programmable commercial transceivers.Οι εμφυτεύσιμες ιατρικές διατάξεις (Implantable Medical Devices, IMD) προσελκύουν σήμερα υψηλό επιστημονικό ενδιαφέρον για ποικίλες ιατρικές εφαρμογές πρόληψης, διάγνωσης και θεραπείας. Βασικό στοιχείο της λειτουργίας τους είναι η δυνατότητα επικοινωνίας με εξωτερικές διατάξεις επίβλεψης/ελέγχου, γνωστή ως ιατρική τηλεμετρία. Στόχος της παρούσας Διδακτορικής Διατριβής είναι η αντιμετώπιση των σημαντικότερων προκλήσεων υπολογιστικής και πειραματικής μελέτης εμφυτεύσιμων κεραιών, ή, ισοδύναμα, κεραιών που ενσωματώνονται επί εμφυτεύσιμων ιατρικών διατάξεων για την επίτευξη ασύρματης ιατρικής τηλεμετρίας. Αρχικά, μελετάται η δυναμική διαφόρων τεχνικών σμίκρυνσης για εμφυτεύσιμες κεραίες, και, βάσει ενός πρωτότυπου παραμετρικού μοντέλου εμφυτεύσιμης κεραίας μικροταινίας, σχεδιάζονται και συγκρίνονται οι επιδόσεις πέντε νέων κεραιών για τηλεμετρία στη ζώνη Υπηρεσιών Επικοινωνίας Ιατρικών Εμφυτευμάτων (Medical Implant Communications Service, MICS) (402–405 MHz). Έμφαση δίνεται στην ποσοτικοποίηση της υποβάθμισης των επιδόσεων ακτινοβολίας και ασφάλειας των εμφυτεύσιμων κεραιών ως συνάρτηση του καταλαμβανόμενου φυσικού τους όγκου. Δοθέντων των αποτελεσμάτων, προτείνεται μία πρωτότυπη εμφυτεύσιμη κεραία μεγάλου εύρους ζώνης, και μία πρωτότυπη εμφυτεύσιμη κεραία διπλής ζώνης συχνοτήτων, οι οποίες καταλαμβάνουν σχετικά αυξημένο φυσικό όγκο προς όφελος των λοιπών επιδόσεων. Στη συνέχεια, αναπτύσσονται και επαληθεύονται αριθμητικά τέσσερις πρωτότυπες μεθοδολογίες σχεδίασης εμφυτεύσιμων κεραιών για λειτουργία εντός συγκεκριμένων σεναρίων εμφύτευσης (θέσεων εμφύτευσης εντός του σώματος του ασθενούς). Στόχο αποτελεί η επιτάχυνση της διαδικασίας σχεδίασης και η βελτιστοποίηση των επιτευχθεισών επιδόσεων συντονισμού. Η επαλήθευση και σύγκριση των προτεινόμενων μεθοδολογιών πραγματοποιείται αριθμητικά στο πλαίσιο σχεδίασης πρωτότυπων κεραιών μικροταινίας για εμφύτευση εντός του ιστού δέρματος του ανθρώπινου κεφαλιού, και ιατρική τηλεμετρία στη ζώνη MICS.Ακολουθεί παραμετρική μελέτη των επιδόσεων συντονισμού, ακτινοβολίας, και ασφάλειας εμφυτεύσιμων κεραιών, ως συνάρτηση: (α) της υπό μελέτη ιατρικής εφαρμογής (θέση εμφύτευσης της κεραίας εντός του σώματος του ασθενούς), (β) των ιδιαιτεροτήτων του εκάστοτε υποκειμένου (ανατομική δομή και ηλεκτρικές ιδιότητες βιολογικών ιστών), και (γ) της συχνότητας στην οποία λαμβάνει χώρα η ιατρική τηλεμετρία. Στόχο αποτελεί η μελέτη της διαλειτουργικότητας των εμφυτεύσιμων κεραιών, και η αξιολόγηση των επιδόσεών τους ως συνάρτηση της συχνότητας λειτουργίας.Έπειτα, μελετώνται θέματα πειραματικής κατασκευής και μέτρησης εμφυτεύσιμων κεραιών. Προτείνονται πρωτότυπες «συνταγές» υγρών και ημι–στερεών εξομοίωσης των ιστών δέρματος και μυός στη ζώνη MICS, και αναπτύσσεται μία πρωτότυπη μεθοδολογία σχεδίασης–και–μέτρησης εμφυτεύσιμων κεραιών, η οποία αποσκοπεί στην ελαχιστοποίηση των σφαλμάτων μεταξύ των αριθμητικών αποτελεσμάτων και πειραματικών μετρήσεων. Η μεθοδολογία επαληθεύεται στο πλαίσιο κατασκευής δύο πρωτότυπων εμφυτεύσιμων κεραιών ζώνης MICS και πειραματικής μέτρησης αυτών εντός προσομοιωμάτων. Η δυναμική των κατασκευασθεισών κεραιών επιδεικνύεται, επιπλέον, μέσω εμφύτευσης και μέτρησης αυτών εντός πειραματόζωων (αρουραίων), κατόπιν ανάπτυξης κατάλληλου πειραματικού πρωτοκόλλου. Η Διατριβή ολοκληρώνεται με υπολογιστικές και πειραματικές μελέτες της ασύρματης ζεύξης τηλεμετρίας που σχηματίζεται μεταξύ εμφυτεύσιμων και εξωτερικών κεραιών. Πραγματοποιείται μοντελοποίηση της ζεύξης μακρινού πεδίου, και αξιολογούνται, υπολογιστικά, οι επιδόσεις αυτής για διάφορες συχνότητες λειτουργίας κεραιών και σενάρια διάδοσης. Στη συνέχεια, σχεδιάζονται, κατασκευάζονται, και μετρώνται πειραματικά δύο εξωτερικές κεραίες για χρήση σε ζεύξεις ασύρματης τηλεμετρίας ζώνης MICS: μία μονοπολική κεραία, και μία πρωτότυπη φορετή κεραία μικροταινίας διπλής ζώνης. Ακολουθεί υπολογιστική και πειραματική μελέτη του συντελεστή μετάδοσης και του μέγιστου δυνατού εύρους επικοινωνίας μεταξύ εμφυτεύσιμων και εξωτερικών κεραιών κατά την απομονωμένη λειτουργία τους αλλά και κατά τη λειτουργία τους επί προγραμματιζόμενων εμπορικών πομποδεκτών

Real-Time Magnetocardiography with Passive Miniaturized Coil Array in Earth Ambient Field

We demonstrate a magnetocardiography (MCG) sensor that operates in non-shielded environments, in real-time, and without the need for an accompanying device to identify the cardiac cycles for averaging. We further validate the sensor’s performance on human subjects. Our approach integrates seven (7) coils, previously optimized for maximum sensitivity, into a coil array. Based on Faraday’s law, magnetic flux from the heart is translated into voltage across the coils. By leveraging digital signal processing (DSP), namely, bandpass filtering and averaging across coils, MCG can be retrieved in real-time. Our coil array can monitor real-time human MCG with clear QRS complexes in non-shielded environments. Intra- and inter-subject variability tests confirm repeatability and accuracy comparable to gold-standard electrocardiography (ECG), viz., a cardiac cycle detection accuracy of >99.13% and averaged R-R interval accuracy of <5.8 ms. Our results confirm the feasibility of real-time R-peak detection using the MCG sensor, as well as the ability to retrieve the full MCG spectrum as based upon the averaging of cycles identified via the MCG sensor itself. This work provides new insights into the development of accessible, miniaturized, safe, and low-cost MCG tools

Colorful Textile Antennas Integrated into Embroidered Logos

We present a new methodology to create colorful textile antennas that can be embroidered within logos or other aesthetic shapes. Conductive threads (e-threads) have already been used in former embroidery unicolor approaches as attributed to the corresponding conductive material, viz. silver or copper. But so far, they have not been adapted to ‘print’ colorful textile antennas. For the first time, we propose an approach to create colorful electronic textile shapes. In brief, the embroidery process uses an e-thread in the bobbin case of the sewing machine to embroider the antenna on the back side of the garment. Concurrently, a colorful assistant yarn is threaded through the embroidery needle of the embroidery machine and used to secure or ‘couch’ the e-threads onto the fabric. In doing so, a colorful shape is generated on the front side of the garment. The proposed antennas can be unobtrusively integrated into clothing or other accessories for a wide range of applications (e.g., wireless communications, Radio Frequency IDentification, sensing)