Read Range Research Articles

Non-invasive carbon dioxide monitoring during moderate sedation at different oxygen flow rates in patients undergoing endoscopic retrograde cholangio-pancreatography

ABSTRACT Background All patients receiving sedation to facilitate endoscopic procedures should have monitoring of cardiorespiratory parameters before, during, and after administration of sedation/analgesia. We evaluated the effects of different O2 flow rates on the non-invasive CO2 monitoring (EtCO2) in adult patients that were breathing spontaneously under moderate sedation during ERCP. Methods This prospective randomized double-blind study was conducted on 120 patients assigned randomly to one of the three equal groups (n = 40) (Group I; 2 L/min oxygen flow rate, Group II; 4 L/min oxygen flow rate, and Group III; 6 L/min oxygen flow rate). Primary outcome was EtCO2 at the end of procedure. Secondary outcomes included peripheral O2 saturation, hemodynamics, time to recovery, total propofol dose, patients’ satisfaction, sedation score, and complications. Results EtCO2 increased significantly between the studied groups at pre-intervention, induction, 5, 10, 20, and 30 min but without any clinical significance (p-value ˂ 0.05). The HR changes were statistically significant at 10 and 20 min after induction of anesthesia. While SpO2, MBP, and RR differences were statistically not significant between groups throughout the whole study periods (p-value >0.05). Arterial blood gas analysis showed PCO2 was significantly different between the study groups but still within the normal range of readings, while pH and HCO3 showed statistically insignificant differences between the three groups. Conclusion The study demonstrated that different O2 flow rates did not affect the non-invasive EtCO2 measurements by the Dual-Guard device during moderate sedation in patients undergoing ERCP. Non-invasive EtCO2 monitoring can provide an early warning sign of hypoventilation during moderate sedation.

High Gain Passive UHF RFID Reader Antenna Using Novel FSS for Longer Read Range

Frequency Selective Surface (FSS) is widely used to enhance the gain of antenna & reduces Electromagnetic Interference (EMI). In this work, a novel Frequency Selective Surface (FSS) is designed, analyzed, and fabricated along with passive Radio Frequency Identification (RFID) reader antenna operating at global Ultra-High Frequency (UHF) for wireless RFID applications. The antenna & FSS sheet is fabricated on less costly FR4 substrate with resonant bandwidth of 860–960 MHz. The Fabry–Perot arrangement of FSS sheet with antenna increases the gain & directivity without modifying the antenna profile or increasing radiation patch size. The maximum measured gain is 9.8 dB & 7.2 dB with the Reflection coefficient (S11) of −35 dB & −15 dB at 910 MHz & 950 MHz respectively. The proposed antenna of dimension 40 mm by 40 mm is fabricated & tested for further experimental validation with measured read range longer than 8 m. The novelty in proposed work is integration of FSS with passive UHF RFID technology which can be effectively used in wireless RFID applications for improved read range, higher gain, lower power consumption & better immunity within the resonating band. The proposed antenna effectively isolates out-of-band frequencies from in-band frequencies over a required bandwidth reducing Electromagnetic Interference (EMI) for UHF RFID applications.

Antenna Characteristics Contributions to the Improvement of UWB Real-Time Locating Systems’ Reading Range and Multipath Mitigation

Antenna Characteristics Contributions to the Improvement of UWB Real-Time Locating Systems’ Reading Range and Multipath Mitigation

Dielectric Waveguide Filled With Particulate Media for Ultrahigh Frequency (UHF) Radio Frequency Identification (RFID) Applications

Radio frequency identification (RFID) is a wireless communication technique that has a wide variety of applications in many fields. In some cases, the read range of the RFID transponder is a limiting factor to the application; thus, it is desired that the read range of a given RFID system be maximized. This paper presents a method to extend the read range of UHF RFID signal (860-960 MHz) by using cost-effective dielectric particulate materials (e.g., dry sand) as filler in dielectric waveguides, which is useful for applications that employ UHF RFID as a sensing or communication tool that need long read ranges, e.g., underground pipeline corrosion monitoring or leak detection. Reading tests conducted in both laboratory (air) and underground showed that the transmission of the UHF RFID signal through dielectric particulate media can considerably extend the read range of passive RFID transponders, which makes it a good material choice for the manufacturing of wireless monitoring systems for underground infrastructures. Classic waveguide theories developed by Marcatili and Emslie et al. were modified to analyze the transmission of the UHF RFID signal in the waveguide filled with dielectric particulate media. Reasonably good agreement was observed between the measured and calculated power values.

Motion-Modulated Chipless RFID

This paper addresses the new type of backscatter communication based on motion-modulated chipless Radio Frequency IDentification (RFID) tags. To clearly explain the concept, the different methods of backscatter communication are classified from a system point of view based on the two fundamental properties of linearity and variation in time. The principle of classical chipless RFID technology, as a non-modulated backscatter method, and the motion-modulated chipless RFID are described with general mathematical demonstrations, while the performance of the two approaches is compared in terms of read range. Motion-modulated chipless RFID is presented as an effective backscatter communication method for identification and sensing of moving objects at large distances. Three different types of motion-induced modulation as phase (Doppler) modulation, polarization modulation, and directional modulation are addressed based on three specially designed moving resonant scatterers. The modulation process in each case is theoretically described, and the performance of the motion-modulated tag is experimentally verified in terms of identification capability and large read range.

Measuring Arterial Oxygen Saturation Using Wearable Devices Under Varying Conditions.

INTRODUCTION: Recently developed wearable monitoring devices can provide arterial oxygen saturation (Spo₂) measurements, offering potential for use in aerospace operations. Pilots and passengers are already using these technologies, but their performance has not yet been established under conditions experienced in the flight environment such as environmental hypoxia and concurrent body motion.METHODS: An initial evaluation was conducted in 10 healthy subjects who were studied in a normobaric chamber during normoxia and at a simulated altitude of 15,000 ft (4572 m; 11.8% oxygen). Spo₂ was measured simultaneously using a standard pulse oximeter and four wearable devices: Apple Watch Series 6; Garmin Fēnix 6 watch; Cosinusso Two in-ear sensor; and Oxitone 1000M wrist-worn pulse oximeter. Measurements were made while stationary at rest, during very slight body motion (induced by very low intensity cycling at 30 W on an ergometer), and during moderate body motion (induced by moderate intensity cycling at 150 W).RESULTS: Missed readings, defined as failure to record an Spo₂ value within 1 min, occurred commonly with all wearables. Even with only very slight body motion, most devices missed most readings (range of 12-82% missed readings) and the rate was higher with greater body motion (range 18-92%). One device tended to under-report Spo₂, while the other devices tended to over-report Spo₂. Performance decreased across the devices when oxygenation was reduced.DISCUSSION: In this preliminary evaluation, the wearable devices studied did not perform to the same standard as a traditional pulse oximeter. These limitations may restrict their utility in flight and require further investigation.Hearn EL, Byford J, Wolfe C, Agyei C, Hodkinson PD, Pollock RD, Smith TG. Measuring arterial oxygen saturation using wearable devices under varying conditions. Aerosp Med Hum Perform. 2023; 94(1):42-47.

Appendix A

INTRODUCTION: Recently developed wearable monitoring devices can provide arterial oxygen saturation (Spo2) measurements, offering potential for use in aerospace operations. Pilots and passengers are already using these technologies, but their performance has not yet been established under conditions experienced in the flight environment such as environmental hypoxia and concurrent body motion. METHODS: An initial evaluation was conducted in 10 healthy subjects who were studied in a normobaric chamber during normoxia and at a simulated altitude of 15,000 ft (4572 m; 11.8% oxygen). SpO2 was measured simultaneously using a standard pulse oximeter and four wearable devices: Apple Watch Series 6; Garmin Fēnix 6 watch; Cosinusso Two in-ear sensor; and Oxitone 1000M wrist-worn pulse oximeter. Measurements were made while stationary at rest, during very slight body motion (induced by very low intensity cycling at 30 W on an ergometer), and during moderate body motion (induced by moderate intensity cycling at 150 W). RESULTS: Missed readings, defined as failure to record an Spo2 value within 1 min, occurred commonly with all wearables. Even with only very slight body motion, most devices missed most readings (range of 12–82% missed readings) and the rate was higher with greater body motion (range 18–92%). One device tended to under-report Spo2, while the other devices tended to over-report Spo2. Performance decreased across the devices when oxygenation was reduced. DISCUSSION: In this preliminary evaluation, the wearable devices studied did not perform to the same standard as a traditional pulse oximeter. These limitations may restrict their utility in flight and require further investigation.

British Reception of L.N. Tolstoy’s Works in the Threshold of “Russian Boom” of the 1910s

Foreign literature usually enters the field of the other culture obeying certain rules, including readers’ willingness, due to various reasons (political, social, psychological, etc.) to receive just these or those components. Such fragmentation, more or less, is overcome by the efforts of translators, commentators, researchers, critics; if the interest in the other culture is strong enough, the reader sees a relatively coherent picture, though not necessarily it is absolutely true. For many years Russian literature, first regarded as semi-barbarous and then considered to be high, was such an area of exotic interest for the English-speaking readers. Having entered the British range of reading, Leo Tolstoy became one of the cult foreign figures in the United Kingdom. Tolstoy’s reception included several layers: he was read as a bright representative of a foreign culture mainly known through stereotypes, as a great heir of the tradition of the European novel, as a progressive social activist whose creative work achieved the special meaning in the course of the political struggle, as the personified rebuff to the French naturalism and as an earnest religious philosopher leading the others by his example. Selective reception, namely, what caught the eye of the English-speaking auditory first of all, helps us reveal the specifics of the reading of Tolstoy’s works in Britain.

Sterne and Yakovlev: On the reception of Lawrence Sterne in Russia

The article focuses on a little-known episode from the history of Russian-English literary relations. L. Sterne’ s works, “Sentimental Journey through France and Italy” in particular, were included in the range of reading of the educated Russian nobility, and “Sentimental Journey” attracted a wide variety of readers. Sterne’s “Journey” marked the beginning of “sentimental” travel literature in Russian, written by the authors “with eyes, full of tears.” Pavel Yakovlev, a writer of the first half of the 19th century, forgotten today, wrote short plays, novellas, a novel, numerous articles, but he became famous for his parodies. His most famous parody is the novella “Sentimental Journey along Nevsky Prospekt”, first published in parts in the “Blagonamerenny” magazine, and then as a separate book. Yakovlev used Sterne’s story as a kind of a plan recognizable by readers. Borrowing the structure of Sterne’s book helps the development of the plot. Yakovlev also uses various artistic means, a certain vocabulary and syntax, which are inherent in the works by Sterne. Yakovlev’s book is a monologue of the protagonist, which includes the conversations he heard in coffee houses, shops, visiting friends. Like Sterne’s text, Yakovlev’s novella belongs to “oral culture,” that of salons. There are three planes in Yakovlev’s novella: the creation of a literary envelope that holds the attention of readers; a parody of the “sentimental journey” as a literary genre; depiction of scenes from the life of literary Petersburg.

Planar Inverted Antenna With Embedded Patch Excitor for On-Metal Tag Design

For the first time, a non-resonating patch is embedded inside a planar inverted antenna structure for the design of a low-profile metal-mountable tag antenna. The tag has a compact and low profile with a footprint of 40 mm × 40 mm × 3.3 mm. Efficient coupling between the excitation patch and the radiating patch, which are separated by a narrow and long slotline can improve the radiation efficiency. The slotline can provide sufficient shunt capacitance so that the antenna reactance can match with the chip reactance. The antenna and chip impedances are in conjugate match for the proposed tag, maximum power transfer between the chip and the antenna is possible for a better radiation performance. Being tested with 3.28 W effective isotopically radiated power (EIRP), the proposed tag can attain a good read range of 16 m. The tag antennas resonant frequency is very stable, and it is not significantly impacted by the metallic backing object underneath.

Inkjet-Printed UHF RFID Sticker for Traceability and Spoilage Sensing of Fruits

This article presents an ink-jet printed ultrahigh-frequency (UHF) radio frequency identification (RFID) label for tagging fruits. The proposed tag antenna is based on a hybrid configuration, which consists of a loop, dipole-like strips (DLSs), and eye-shaped rectangular nested slots. The loop fulfills impedance matching proposes, while the eye-shaped slots assist to maintain high imaginary impedance to mitigate capacitive effects of high permittivity surfaces of fruits. Moreover, the dipole strips help to reduce the loss resistance caused by the high permittivity of the surface of the fruit. Therefore, the overall tag configuration provides a good impedance match with the Alien H3 RFID chip in the whole U.S. UHF RFID band. Furthermore, the fabricated prototype of the proposed tag antenna achieved a read range of 3 m after mounting on apple. Moreover, an automatic weighing and billing experiment is performed by placing the tagged apples inside a refrigerator. Overall, the performance of the proposed tag antenna is tested after mounting on apple fruits of different shapes and sizes, which indicates the robustness of this tag. Moreover, the tag antenna is also tested for sensing spoilage of apple fruits. The read range of the proposed tag antenna reduces up to 42% on spoiled apples. Therefore, this tag can be suitable for automatic sorting, weighting, and billing of fruits in smart cities, vending machines, and departmental stores.

Compact Measurement Apparatus for 3D Spherical Read Range Characterization of Chipless RFID

Compact Measurement Apparatus for 3D Spherical Read Range Characterization of Chipless RFID

Fully Printed Dual-Layer Depolarizing Chipless RFID Tag for Wearable Applications

This work presents a cross-polar dual-layer chipless radio-frequency identification (RFID) tag based on a ladder-shaped resonator design. An integrated ground plane enables direct attachment to human skin without performance deterioration. Simulations show that the ladder-shaped resonator provides several advantages over traditional L-shaped and straight resonators, including a strong cross-polar radar cross section (-23.4 dBsm), third-order harmonics, orientation insensitivity, and compact size (0.062 λ2). The effects of the ground plane shape on the surface current distribution are investigated, and a circular tag of 20 mm radius is designed using ladder resonator groups and frequency shift encoding to provide an active area of 96.45 bits/λ2 and a unit frequency of 6.03 bits/GHz. The tag substrate is three-dimensionally (3D) printed with metallic resonator patterns that are subsequently screen-printed on the substrate. The maximum read range is measured at 40 mm using a cross-shaped, dual-polarized Vivaldi antenna connected to a network analyzer. The measured characteristics in free space are in good agreement with the simulation results, and practical on-body performance tests for the manufactured prototype using simulation and direct measurements indicate that the tag performance remains stable for both free space and on-body cases. The fully printed fabrication process makes the proposed tag design suitable for mass production at a low cost.

Non Linear Modulation of UHF Tag

This paper presents a new modulation and detection scheme for UHF RFID tags. This detection method is not based on the load switching modulation classically used by the tag to communicate with the reader. The principle relies on the generation of a modulated signal by the reader combined with the non-linearity present in any RFID chip (or other non-linear devices). Under specific conditions, we show that the backscattered signal by the tag due to the non-linearity can produce new frequency components located around the carrier frequency used by the reader. These new components can be easily separated from the leakage and the response of the environment in the frequency domain. Moreover this detection can be done at a power which is significantly lower than the sensitivity of the chip. Thus, the associated detection range can be higher than the classical read range of the tag. In measurements, this detection range can be higher than 20 m for a fully passive tag and represents an enhancement of 30% compared to the classical read range.

Design and Prototyping of a Low-Cost High Frequency Antenna for Vicinity Coupling Devices

This paper describes the development of a high frequency (HF) antenna for high output power vicinity coupling devices (VCDs) operating at 13.56 MHz. Key design parameters, such as RF power level, antenna size, and communication protocol, and their link to the antenna features and requirements, have been discussed. For efficient reader interrogation, detection, and recovery of transponder responses, a tuning circuit necessary to adjust the antenna power matching and resonance characteristics was designed and prototyped. The antenna was fed to an industry standard reader and evaluated for read range performance with vicinity cards. The designed antenna on the reader achieved a good read range, which demonstrated fair agreement with the calculated theoretical results.

Introduction: Angela Carter and Japan—A Global Perspective

There was a dreadful confusion of expectations and I never knew what was going to happen next, because of the confusion. It was both an enriching and a devastating experience, and in many ways it was an affair with Japan itself. (Angela Carter, qtd. in Bell 27) Since her premature death in 1992, Angela Carter has become recognized as one of the most important writers in the English language, with numerous edited collections, theater adaptations, documentaries, and The Bloody Chamber now on the A-Level syllabus cementing her legacy as the “white witch of English Literature” (Day 3). However, while her work has attracted both significant academic interest and popular acclaim, there is a danger that her radical feminist politics have been simplified and even sanitized in the rush to canonize her as a fairy godmother figure, locating her only in a Western literary tradition. What this special issue demonstrates is the importance of not underestimating the impact of Carter’s formative experiences in Japan on her feminist and political consciousness as a writer. The BBC documentary Angela Carter: Of Wolves and Women (produced by Jude Ho, 2018) concurs: “while Carter’s early work drew on her creepily claustrophobic childhood and miserable early marriage, it was her experience of living in Japan in the 1970s that liberated both her writing and her sexuality” (BBC). Yet the impact of Carter’s transformative experience in Japan has been critically overlooked. This special issue addresses this imbalance by bringing together a range of new readings and perspectives on the influence of her life in Japan on her writing and its politics.

Miniature Long-Range Ceramic On-Metal RFID Tag

Radio frequency identification (RFID) is a widely used wireless technology for contactless data exchange between a passive information carrier (tag) and an active interrogation device (reader). Being sensitive to a surrounding environment, RFID tags are usually designed per application. Here, we demonstrate an RFID tag with three essential functions available simultaneously, namely, small footprint, long reading range, and capability of on-metal labeling. Our design is based on a compact high-index ceramic resonator and an inductively coupled small metal ring functionalized with an RFID chip. The tag operates at magnetic dipolar resonance, which interacts with the metal object subject to labeling. Specifically, a 16.5 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times16.5$ </tex-math></inline-formula> mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times12$ </tex-math></inline-formula> mm footprint device, placed on a 40 cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times40$ </tex-math></inline-formula> cm metal sheet, was successfully interrogated from 22 m with no violation of international effective isotropic radiated power (EIRP) standards. Currently, it is the smallest on-metal RFID tag with a reading range of over 20 m. Multifunctional miniature long-range ceramic tags are attractive for use in numerous practical applications, including the Internet of Small Things (IoST) and many others.

Empirical Likelihood-Based Inference for Functional Means with Application to Wearable Device Data

AbstractThis paper develops a nonparametric inference framework that is applicable to occupation time curves derived from wearable device data. These curves consider all activity levels within the range of device readings, which is preferable to the practice of classifying activity into discrete categories. Motivated by certain features of these curves, we introduce a powerful likelihood ratio approach to construct confidence bands and compare functional means. Notably, our approach allows discontinuities in the functional covariances while accommodating discretization of the observed trajectories. A simulation study shows that the proposed procedures outperform competing functional data procedures. We illustrate the proposed methods using wearable device data from an NHANES study.

Methods for downhole soil water sensor calibration—Complications of bulk density and water content variations

AbstractDownhole soil volumetric water content (VWC) sensors are used in access tubes to assess the soil water content at multiple depths. If sensor readings are spaced closely enough vertically and are accurate enough, then accurate soil profile water content storage and change in storage can be determined over the depth range of readings, leading to accurate estimates of evapotranspiration (ET) if readings extend to well below the root zone. Even if sensing only covers the active root zone, soil water depletion may be determined well enough to inform irrigation scheduling. While sensor accuracy is dependent on many factors, including the sensor's physical principle of operation, soil‐specific calibration is typically required for good accuracy. In soils with multiple horizons (layers) of different texture, bulk density (BD), or chemical composition, horizon‐specific calibrations may be necessary. We describe methods and equipment used for downhole sensor calibration to typical accuracy of &lt;0.01 m3 m−3 with specific reference to calibration of 10 neutron scattering meters in a soil that required three different horizon‐specific calibrations. Our results contrast with the factory calibration, which would result in a 38‐mm error in water stored in a 1.5‐m deep profile of our soil. We describe variability of measured VWC and BD with depth, distance, and water content and the errors that result from using BD to convert mass basis (g g−1) water content data to VWC data, which can be as much as 35 mm (7.26% underestimation) for soil water storage in a 1.5‐m deep profile of our soil.

Electromagnetic Assessment of UHF-RFID Devices in Healthcare Environment

In this work, the evaluation of electromagnetic effect of Ultra High Frequency Radio Frequency Identification (UHF-RFID) passive tags used in the healthcare environment is presented. In order to evaluate exposure levels caused by EM field (865–868 MHz) of UHF-RFID readers, EM measurements in an anechoic chamber and in a real medical environment (Hospital Universitario de Canarias), as well as simulations by 3D Ray Launching algorithm, and of biophysical exposure effects in human models are presented. The results obtained show that the EM exposure is localized, in close vicinity of RFID reader and inversely proportional to its reading range. The EM exposure levels detected are sufficient to cause EM immunity effects in electronic devices (malfunctions in medical equipment or implants). Moreover, more than negligible direct effects in humans (exceeding relevant SAR values) were found only next to the reader, up to approximately 30% of the reading range. As a consequence, the EM risk could be firstly evaluated based on RFID parameters, but should include an in situ exposure assessment. It requires attention and additional studies, as increased applications of monitoring systems are observed in the healthcare sector—specifically when any system is located close to the workplace that is permanently occupied.