New Flexible Medical Compact Antenna: Design and Analysis

Abstract

Some results on embedded antennas for medical wireless communication systems are presented. Medical telemetry can advantageously assist medical diagnostics. For example, you can better locate a diseased area by monitoring temperature inside the human body. In order to establish efficient wireless links in such an environment, a special attention should be paid to the antenna design. It is required to be of a low profile, very small regardless of the working frequency—434 MHz in the ISM band, safe, and cost effective. Design of the as-considered antenna is proposed based on a simple model. The approach has been demonstrated for a compact flexible antenna with a factor of 10 with respect to the half-wave antenna, rolling up inside an ingestible pill. Measured and calculated impedance behaviour and radiation characteristics of the modified patch are determined. Excellent agreement was found between experiment and theory.

An Ultrawideband Conformal Antenna at 433 MHz for Wireless Capsule Endoscope of Pediatric Patients

“…In this paper, we propose an ultrawideband conformal loop antenna attached on the outer-wall of a capsule module with the size of 19.5 mm × 10 mm operating at 433 MHz industrial, scientific and medical (ISM) band. The simulation results show that proposed antenna has a BW −10dB of 1912 MHz (288-2200 MHz), which is a much wider than reported existing designs, and allows a much smaller capsule size except for that in [6], [10]. It was also demonstrated that the proposed antenna is robust against changes of surrounding environments such as other components in the capsule, different tissues in the digestive tract, different locations, and varying orientations inside the body.…”

“…In addition to the requirement of miniaturization, the bandwidth of the antenna needs to be as wide as possible to overcome the detuning effects due to varying tissue properties through the digestive tract, as well as to realize higher data rates. According to the author's best knowledge, the smallest capsule antenna is reported for a capsule with a size of only 17 mm × 7 mm in [6] and [10], but the BW −10dB is only 17 MHz and 53 MHz, respectively. Keeping in mind the operation environment of a WCE system, these matching bandwidths are relatively narrow.…”

Antenna System Design for Improved Wireless Capsule Endoscope Links at 433 MHz

“…The in-body antenna needs to be fitted into a small capsule, and the bandwidth requires to be wide enough to overcome the detuning effects due to varying tissue properties throughout the GI tract. Recent research has shown embedded [24]- [33] and conformal structures [7], [9], [17], [34]- [41], [43]- [45] as promising capsule antenna types. Embedded antennas are placed inside the capsule cavity.…”

Modeling and Characterization of in-Body Antennas

“…Cheng et al proposed a complementary split-ring resonator (CSRR) loaded 2.45-GHz patch antenna. Mahe et al employed λ\4 stepped impedance resonator along with meandering to miniaturize the microstrip antenna [42]. Recently, we reported a methodology [43] and a miniature 434-MHz antenna design [39] capable of efficient operation from all tissues with high water contents.…”

“…The λ/2 stepped-impedance resonator can be accurately modeled using the transmission-line-impedance equation (the derivation is given in [42]):…”