Generalized Parity-Time Symmetry Condition for Enhanced Sensor Telemetry

Wireless sensors based on micro-machined tunable resonators are important in a variety of applications, ranging from medical diagnosis to industrial and environmental monitoring.The sensitivity of these devices is, however, often limited by their low quality (Q) factor.Here, we introduce the concept of isospectral party time reciprocal scaling (PTX) symmetry and show that it can be used to build a new family of radiofrequency wireless microsensors exhibiting ultrasensitive responses and ultrahigh resolution, which are well beyond the limitations of conventional passive sensors. We show theoretically, and demonstrate experimentally using microelectromechanical based wireless pressure sensors, that PTXsymmetric electronic systems share the same eigenfrequencies as their parity time (PT)-symmetric counterparts, but crucially have different circuit profiles and eigenmodes. This simplifies the electronic circuit design and enables further enhancements to the extrinsic Q factor of the sensors

Modern Telemetry

Telemetry is based on knowledge of various disciplines like Electronics, Measurement, Control and Communication along with their combination. This fact leads to a need of studying and understanding of these principles before the usage of Telemetry on selected problem solving. Spending time is however many times returned in form of obtained data or knowledge which telemetry system can provide. Usage of telemetry can be found in many areas from military through biomedical to real medical applications. Modern way to create a wireless sensors remotely connected to central system with artificial intelligence provide many new, sometimes unusual ways to get a knowledge about remote objects behaviour. This book is intended to present some new up to date accesses to telemetry problems solving by use of new sensors conceptions, new wireless transfer or communication techniques, data collection or processing techniques as well as several real use case scenarios describing model examples. Most of book chapters deals with many real cases of telemetry issues which can be used as a cookbooks for your own telemetry related problems

Antenna Development in Brain-Implantable Biotelemetric Systems for Next-Generation of Human Healthcare

In the growing efforts of promoting patients’ life quality through health technology solutions, implantable wireless medical devices (IMDs) have been identified as one of the frontrunners. They are bringing compelling wireless solutions for medical diagnosis and treatment through bio-telemetric systems that deliver real-time transmission of in-body physiological data to an external monitoring/control unit. To set up this bidirectional wireless biomedical communication link for the long- term, the IMDs need small and efficient antennas. Designing antenna-enabled biomedical telemetry is a challenging aim, which must fulfill demanding issues and criteria including miniaturization, appropriate radiation performance, bandwidth enhancement, good impedance matching, and biocompatibility. Overcoming the size restriction mainly depends on the resonant frequency of the required applications. Defined frequency bands for biomedical telemetry systems contain the Medical Implant Communication Service (MICS) operating at the frequency band of 402– 405 MHz, Medical Device Radiocommunication Service (MedRadio) resonating at the frequency ranges of 401– 406 MHz, 413 – 419 MHz, 426 – 432 MHz, 438 – 444 MHz, and 451 – 457 MHz, Wireless Medical Telemetry Service (WMTS) operating at frequency specturms of 1395 to 1400 MHz and 1427 to 1432 MHz, and Industrial, Scientific, and Medical (ISM) bands of 433.1–434.8 MHz, 868–868.6 MHz, 902.8–928.0 MHz, and 2.4–2.48 GHz. On the other hand, a single band antenna may not fulfill all requirements of a bio-telemetry system in either MedRadio, WMTS, or ISM bands. As a result, analyzing dual/multi-band implantable antenna supporting wireless power, data transmission, and control signaling can meet the demand for multitasking biotelemetry systems. In addition, among different antenna structures, PIFA has been found a promising type in terms of size-performance balance in lossy human tissues. To overcome the above-mentioned challenges, this thesis, first, starts with a discussion of antenna radiation in a lossy medium, the requirements of implantable antenna development, and numerical modeling of the human head tissues. In the following discussion, we concentrate on approaching a new design for far-field small antennas integrated into brain-implantable biotelemetric systems that provide attractive features for versatile functions in modern medical applications. To this end, we introduce three different implantable antenna structures including a compact dual-band PIFA, a miniature triple-band PIFA and a small quad-band PIFA for brain care applications. The compelling performance of the proposed antennas is analyzed and discussed with simulation results and the triple-band PIFA is evaluated using simulation outcomes compared with the measurement results of the fabricated prototype. Finally, the first concept and platform of in-body and off-body units are proposed for wireless dopamine monitoring as a brain care application. In addition to the main focus of this thesis, in the second stage, we focus on introducing an equivalent circuit model to the electrical connector-line transition. We present a data fitting technique for two transmission lines characterization independent of the dielectric properties of the substrate materials at the ultra-high frequency band (UHF). This approach is a promising solution for the development of wearable and off-body antennas employing textile materials in biomedical telemetry systems. The approach method is assessed with measurement results of several fabricated transmission lines on different substrate materials

Frontiers of robotic endoscopic capsules: a review

Digestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd., is an example of disruptive technology and represents an attractive alternative to traditional diagnostic techniques. WCE overcomes conventional endoscopy enabling inspection of the digestive system without discomfort or the need for sedation. Thus, it has the advantage of encouraging patients to undergo gastrointestinal (GI) tract examinations and of facilitating mass screening programmes. With the integration of further capabilities based on microrobotics, e.g. active locomotion and embedded therapeutic modules, WCE could become the key-technology for GI diagnosis and treatment. This review presents a research update on WCE and describes the state-of-the-art of current endoscopic devices with a focus on research-oriented robotic capsule endoscopes enabled by microsystem technologies. The article also presents a visionary perspective on WCE potential for screening, diagnostic and therapeutic endoscopic procedures

Wireless Technologies for Implantable Devices

Wireless technologies are incorporated in implantable devices since at least the 1950s. With remote data collection and control of implantable devices, these wireless technologies help researchers and clinicians to better understand diseases and to improve medical treatments. Today, wireless technologies are still more commonly used for research, with limited applications in a number of clinical implantable devices. Recent development and standardization of wireless technologies present a good opportunity for their wider use in other types of implantable devices, which will significantly improve the outcomes of many diseases or injuries. This review briefly describes some common wireless technologies and modern advancements, as well as their strengths and suitability for use in implantable medical devices. The applications of these wireless technologies in treatments of orthopedic and cardiovascular injuries and disorders are described. This review then concludes with a discussion on the technical challenges and potential solutions of implementing wireless technologies in implantable devices

Design and fabrication of a MEMS passive pressure sensor

Micro-ElectroMechanical Systems is an inter-disciplinary technology field that has seen considerable growth over the years. It utilizes conventional semiconductor fabrication process flow as well as novel micro-fabrication techniques to create highly integrated ElectroMechanical systems such as sensors, actuators, switches, pumps and other devices with a wide range of industrial applications. By providing the capability of creating System-On-A-Chip, MEMS technology offers the prospect of highly sophisticated and integrated systems that are very low cost. The purpose of this project is to design, fabricate, and test a MEMS based, passive pressure sensor as a proof of concept targeted at possible remote sensing applications. For the targeted applications, purely passive sensor is a better alternative to sensors involving active circuitry, since it removes much of the design complexities from the sensor, and no battery is needed. Information such as technology selection, analysis of the sensor\u27s response to pressure, and detailed fabrication process flow will be presented. Results from laboratory testing will also be presented

Inductively Powered Implantable System with Far-field Data Transmitter for an Intracranial Pressure Monitoring Application: Design and Performance Validation

Monitoring of the intracranial pressure (ICP) is an essential activity for many brain diseases and injuries. For an adult, ICP value is between 7 mmHg to 15 mmHg . However, for a critically ill patient, the ICP should be maintained below 20 mmHg. Therefore, continuous monitoring of ICP is a life-saving activity. Several invasive and non-invasive methods have been proposed for monitoring of the ICP. However, invasive methods cannot be used for continuous monitoring of the ICP due to the risk of infection. Moreover, non-invasive methods lack in accuracy.Therefore, many researchers reported battery-powered or fully passive implantable systems. However, a battery-powered implant has limited life and large size. On the other hand, in a fully passive implant the readout distance is relatively small in comparison with a battery-powered implant due to its zero-power operation.In contrast, this work presents the development of an inductively powered implantable system equipped with a data transmission unit for an ICP monitoring application. The developed system has three main parts: an implant or in-body unit, an on-body unit and an off-body unit. The on-body unit powers the implant through inductive near-field link. After the activation, the implant, consists of a piezoresistive pressure sensor and a data transmission unit, transmits the pressure signal at the industrial, scientific, and medical radio (ISM) band of 2.45 GHz. The off-body unit receives the transmitted signal from the implant and estimates the pressure value.The simulation and the measurement results of both near-filed and far-field links are presented. After the development of the system, the pressue readout measurement results have been presented in the air, water and in a setting mimicking the human head dielectric properties. For biocompatibility, the implant is coated with biocompatible adhesive silicone. The effect of coating on both wireless links has also been studied.Finally, this work also presents the effect of misalignment between the inductively coupled antennas on the pressure readout accuracy of the developed ICP monitoring system and discusses the solution to overcome this impact. The thesis also presents the response of the developed ICP monitoring system with the change in the temperature

Implantable antennas for biomedical applications

Recently, the interest in implantable devices for biomedical telemetry has significantly increased. Amongst the different components of the implantable device, the antenna plays the most significant role in the wireless data transmission. However, the human body around the antenna alters its overall characteristics and absorbs most of its radiation. Therefore, this thesis is mainly focused on improving the antenna characteristics (bandwidth and radiation efficiency) to overcome the human body effect and investigating new structures that reduce the power absorption by the human body tissues. A novel antenna design methodology is developed and used to design new flexible implantable antennas of much lighter weight, larger radiation efficiency, and wider bandwidth than existing embedded antennas. These antennas work for multiple ((401-406 MHz) MedRadio, 433 MHz and 2.45 GHz ISM) bands which satisfy the requirements of low power consumption and wireless power transfer. This has been combined with thorough investigations of the antenna performance in the anatomical human body. New effective evaluation parameters such as the antenna orientation are investigated for the first time. New structures inspired by complementary and multiple split ring resonators (CSRRs and MSRRs) are designed. The structures are found to reduce the electric near field and hence the absorbed power which increases the radiated power accordingly. This new promising function of metamaterial based structures for implantable applications is investigated for the first time. The path loss (between pacemaker and glucose monitoring implantable antennas inside the anatomical body model) and (between an implantable and external antennas for a wireless power channel at 433 MHz) are estimated. Moreover, the optimum antenna type for on-in body communication is investigated. Loop antennas are found to outperform patch antennas in close proximity to the human body

Design of a wireless platform for wearable and home automation applications

Title from PDF of title page, viewed on October 2, 2012Thesis advisor: Walter D. León-SalasVitaIncludes bibliographic references (p. 147-[151])Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2012In the recent past, a great deal of attention has been given to wireless sensors. Wireless sensors enable a multitude of applications such as environmental monitoring, medical care, disaster response, home automation, urban scale monitoring, gaming etc. These small, low-power, multifunctional sensors includes sensing, data processing and communication components representing a significant improvement over the traditional sensors. The two attractive wireless sensor applications investigated in this thesis are wearable sensors for bio-medical applications and a ZigBee wireless network for home automation applications. The targeted bio-medical application is bone strain monitoring. The current setup to collect strain data is composed of a data acquisition unit connected to a bench top load instrument. For accurate measurements the lab animals have to be sedated and immobilized in the current setup which is also bulky. A telemetry unit equipped with strain gages designed for implantable measurement of bone strain was designed to address this problem. The measurements collected by an implantable telemetry unit are of high interest to orthopedic researchers who wish to know the load acting on an orthopedic implant and hence to help guide the rehabilitation outcomes in a patient. This thesis describes two small telemetry units with multiple configurable sensor channels which can be used to sense resistance and voltage. Thus, the designed units can be used in home energy monitoring applications as well. The units have low power consumption and were designed using off-the-shelf components. Their dimensions are 24 mm x 13 mm and 10 mm x 10 mm. The sensor signals are multiplexed, modulated and transmitted to a remote computer by means of a radio transceiver. Besides measuring strain integrated levels the telemetry units can also measure acceleration in 3 axes. Wireless battery charging is another feature that was included in our design which is a key feature for surgically implanted devices. To show that our telemetry units has comparable accuracy and compactness to the current setup, we present the readings from both setups. A ZigBee wireless sensor network to monitor and control home appliances was designed and successfully tested. A central control unit is the coordinator which sets up the network and configures the ZigBee network parameters. The battery powered sensors are configured as end-devices which periodically report sensor data such as light, temperature, accelerometer and energy consumption values to the coordinator. Any home appliance limited to less than 10 Amps in the ZigBee network can be turned on or off from the central control unit. With bidirectional communication achieved between the central control unit and the end-device, we were able to achieve a home automation system.Introduction -- Background -- Telemetry unit architecture -- Data collection and results -- Conclusion and future work -- Appendix A.1. Four layer PCB layout of the eight channel telemetry unit -- Appendix A.2. Four layer PCB layout of the four channel telemetry uni