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This article’s objective is to discuss the anatomical and technical challenges associated with designing subcutaneously implanted antennas for continuous wireless medical telemetry. One challenge in this design process is the connection between simulation setup and the anatomical layering of tissues in biological systems. This article presents an overview of the layers of tissues associated with subcutaneous implant (epidermis, dermis, and hypodermis) as well as the measured dielectric properties of these tissues. In addition, this study presents the design and measurement of an implantable dual-band antenna operating on the wireless medical telemetry service (WMTS) (1.395–1.432 GHz) and industrial, scientific, and medical (ISM) (2.4–2.5 GHz) communication bands. This antenna was validated ex vivo and in vivo using porcine animal models. The antenna has a simulated bandwidth of 2.3% for WMTS and 5.7% for ISM bands. In addition, the antenna saw a 300 MHz shift, ex vivo , to the right for WMTS while not having a shift for the ISM band. For in vivo validation, two antennas were made and tested in a porcine animal model and both show an adequate transmission range of 10 m.

This article discusses challenges in designing optically transparent antennas and filters for smart city applications. The smart city concept seeks to alleviate urban challenges that include infrastructure and network capacity. The proposed frequencies for the next generation of wireless networks (5G) would result in shorter broadcast distances and network dead zones. Additional access points and signal repeaters embedded into the existing infrastructure, by inserting transparent antennas into windows via either meshed conductors or transparent conductive oxides (TCOs), would help to mitigate these issues. Glass-embedded frequency-selective surfaces (FSSs) can be used anywhere that requires microwave filtering and optical transparency. The cyberphysical system security in this forthcoming network also poses challenges to entities that require strict network security. This article focuses mainly on TCOs, particularly doped zinc oxide (ZnO), as promising material for transparent antennas and filters. To demonstrate the potential of ZnOs as highly transparent conductive materials for antenna and filter applications, we designed, fabricated, and tested a gallium-doped ZnO- (GZO) based optically transparent 2.4-GHz Wi-Fi antenna and two FSSs (bandpass and bandstop filters) operating in the 23-29-GHz frequency range. These results confirm the potential for ZnO-based TCOs as suitable alternatives to indium tin oxide (ITO) for microwave applications.

This paper presents the design, fabrication, and test of antennas intended to be used for implantable biosensors. With the rising number of Americans managing chronic diseases, implantable biosensors offer better access to vital information for the management of these diseases. Diabetes, particularly, is managed by many through the means of a finger prick monitor, offering only a snap shot of blood glucose at a particular time without showing trends of a rise or fall in the glucose levels. Implantable sensors not only offer these trends via a continuous monitor, a fully implantable sensor offers these trends without the inconvenience of a monitoring system extending outside of the human body. Such appendages hinder the normal activity of patients monitoring their chronic diseases. Due to their full implantation, the sensor monitor needs to broadcast the analyte date from the human body outward to an external data collector. This broadcast requires an antenna made of a biocompatible antenna that operates on frequency bands allocated for medical telemetry as well as frequency bands allocated for unlicensed communication (e.g. WiFi and Bluetooth). This paper presents antennas designed using a biocompatible material Titanium Nitrite (TiN) for subcutaneous implant. The antennas presented operate on the Wireless Medical Telemetry System (WMTS) frequency band and the 2.4 GHz Industrial, Scientific, and Medical (ISM) frequency band.

This contribution presents the design and simulation of finite size narrow band transmission filters for applications in realtime and remote short wave infrared (SWIR) spectroscopy and imaging. The results can ultimately be extended to hyperspectral imaging that has gained interest in many fields ranging from agriculture to surveillance. As chemical compounds possess unique set of sharp spectral signatures, they can be differentiated using wideband spectral scanning. However, such standard approaches require bulky instruments and long acquisition times together with post-processing of acquired data. These technological bottlenecks result in a diminished usefulness of such systems in scenarios demanding short response times, such as law enforcement, homeland security, and military applications. To overcome these limitations, narrow-band and pixel-size filters can be incorporated to focal plane arrays for real-time spectral imaging systems. In this study, we explored several designs of narrow-band, finite-sized (

In this letter, we present a small implantable antenna for MedRadio (401-406 MHz) and ISM (433-434.8 MHz) bands. The antenna is designed to be implanted under the skin and therefore tested by using skin-mimicking gels. We found very good agreement between the simulated and measured return loss. The antenna provided reliable data telemetry up to 20 m when tested indoors.

Summary form only given. The conventional monitoring technologies at the bedside in the hospital consist of a body-worn device and central monitoring station with wired connections. At the hospital settings, the patients' vital parameters such as blood pressure, ECG, temperature, oxygen saturation can easily be monitored through a nurse stationed at the central monitoring station. Although this technology offers unique features and timely patient monitoring and treatment for patients in the clinic, there is no technology to continually monitor the health conditions of the patients after they are released from the hospital. Development of wireless telehealth technologies is critical in providing a solution to this clinical need. Such devices that can provide the wireless telemetry consist of three parts; the sensor, associated electronics and the telemetry unit. In this study, we develop an alternate communication approach using wireless communication and new display technologies to assist healthcare providers in monitoring patients outside the clinic. Our main concentration will be the telemetry link and associated electronics therefore we chose a temperature sensor to show the validity and functionality of the device. More specifically, we investigate the efficiency and practicability for a wireless network in a two channel temperature monitoring system. Two wireless protocols were investigated: a Bluetooth (IEEE 802.15.1) ad-hoc network and a Wi-Fi (IEEE 802.11) ad-hoc network. To do so, two subsystems were designed: a sensor system and a display system. The sensor system consists of two thermometers and a wireless transmitter/receiver. The data will be communicated to the display system wirelessly. The display consists of a wireless transmitter/receiver and a iOS mobile device. The results concerning the efficacy and practicability of the designed system and the integration with a radiometer will be presented.

Recently, Microwave (MW) ablation emerged as a new technology with potential to eliminate the problems associated with RF ablation. In contrast to RF ablation, MW ablation uses higher frequencies (915 MHz and 2.4 GHz) and work on an electromagnetic energy propagation principle. When the microwave power is turned on, an antenna on the MW probe radiates electromagnetic energy into the tissue creating the ablation zone. As a result, MW ablation can be used for many organs such as lung and bones with higher impedance values where RF ablation would fail. Although microwave ablation therapy offers unique advantages over conventional radio frequency ablation therapy such as reduced ablation time, larger ablation zones, elimination of ground pads etc., there are still major problems associated with the existing microwave ablation devices on the market. Current devices use either dipole or slot antennas to deposit electromagnetic energy into the tissue. Such antennas are known to be very narrow band. During the design process, these antennas are matched to the tissue impedance at the frequency of operation (existing devices work at 915 MHz or 2.4 GHz). However, as soon as the microwave power is turned on, the electrical properties of the tissue (dielectric constant - er and conductivity - σ) change due to increased temperature in the tissue. As a result, the power transmission characteristics of the entire system deteriorate. In order to better understand the power transmission characteristics of ablation antennas, we studied the microwave electrical properties of porcine liver, lung, and heart using the Agilent 805070 E slim form probe, a fiber optic temperature probe, and a smooth surface heat source. We manipulated the temperature from 25 °C to 80 °C and measured the dielectric properties between 500 MHz and 20 GHz.

Although microwave ablation offers unique advantages over RF ablation, there are still issues with current microwave ablation devices. This is because the current microwave ablation devices use either dipole or slot antennas to deposit electromagnetic energy into the tissue. Such antennas are known to be very narrow band. During the design process, these antennas are matched to the tissue impedance at the frequency of operation (existing devices work at 915 MHz or 2.4 GHz). However, as soon as the microwave power is turned on, the electrical properties of the tissue (dielectric constant - er and conductivity - σ) change due to increased temperature in the tissue. As a result, the power transmission characteristics of the entire system deteriorate. This temperature increase can be as high as 60 °C raising the local tissue temperature up to ~100 °C. In order to understand the overall ablation device treatment efficiency, there is a need to explore the effect of the temperature on power delivery into the tissue. Therefore, in this study, we investigate the power transmission characteristics of a printed dipole antenna within liver, lung and heart tissues. Two microstrip dipole antennas designed for both 915 MHz and 2.4 GHz. The liver, lung and heart tissues along with antennas and temperature probe, is placed on a heating element to increase the temperature of the tissue. The return loss was measured at 5 °C (indicated by the temperature probe) intervals from 25 °C to 80 °C. We will present results regarding the effect of temperature on power transmission efficiency.