Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz

Chirwa, L.C.; Hammond, P.A.; Roy, S.; Cumming, David R. S.

doi:10.1109/tbme.2003.809474

Cited by 176 publications

(65 citation statements)

References 19 publications

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“…The most suitable unlicensed frequency bands for ingestible applications are MedRadio (Medical Device Radiocommunications Service) (401 to 406, 413 to 419, 426 to 432, 438 to 444, 451 to 457) MHz, and mid-ISM (the Industrial, Scientific and Medical) (433 to 434.8) MHz [12]. As for implantable applications, the closer the antenna is to the skin, the less the signal attenuates within the tissue.…”

Section: A Operating Frequency Choicementioning

confidence: 99%

Long-Range Antenna Systems for In-Body Biotelemetry: Design Methodology and Characterization Approach

2017

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Abstract-Long-range in-body biomedical telemetry enables monitoring of physiological parameters while maintaining mobility and freedom of movement. This emerging technology creates new applications in medicine, clinical research, wellness, and defense. Current in-body biotelemetry devices operate within about a meter around a user that limits their applicability. Here we examine the variety of approaches that, combined, can significantly extend the operating range. The radiation efficiency is constrained by attenuation and reflection losses in tissues. First, choosing an optimal operating frequency can minimize the losses. A specific antenna design is then required to decouple the antenna from a body. Two successful antenna design approaches are reviewed: (1) using loop antennas and (2) dielectrically loaded microstrip antennas. On-body matching layers and repeaters can be used to further improve power transmission. Finally, we present the radiation characterization method for in-body antennas in spherical phantoms with a direct illumination technique using an analog fiber optic link.

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Section: A Operating Frequency Choicementioning

confidence: 99%

Long-Range Antenna Systems for In-Body Biotelemetry: Design Methodology and Characterization Approach

2017

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“…Figure 5 shows several investigated anatomical regions for various in vivo WBAN applications. For example, the heart area has been studied for implantable cardioverter defibrillator and pacemakers, while the gastrointestinal tract (GI) including esophagus, stomach and intestine has been Brain: [29], [38] Right Neck & Shoulder: [28] Clavicle: [16] Esophagus: [6] Left pectoral muscle: [28] Heart: [27], Stomach: [6], [27] , [28], [30] Arm: [16], [28] Intestine: [6], [39] Bladder: [27], Hand: [16] Leg: [28] investigated for WCE applications. The bladder region is studied for wirelessly controlled valves in the urinary tract and the brain is investigated for neural implants [29], [38].…”

Section: In Vivo Em Wave Propagation Modelsmentioning

confidence: 99%

“…As a result, the path loss is greater in the intestine than in the stomach even at equal in vivo antenna depths [6]. Also, more radiation occurs in the anterior region than in the posterior region due to the human body structure [27], [39].…”

Section: In Vivo Em Wave Propagation Modelsmentioning

confidence: 99%

In Vivo Communications: Steps Toward the Next Generation of Implantable Devices

Demir

Ankarali

Abbasi

et al. 2016

IEEE Veh. Technol. Mag.

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Abstract-In vivo wireless medical devices have the potential to play a vital role in future healthcare technologies by improving the quality of human life. In order to fully exploit the capabilities of such devices, it is necessary to characterize and model the in vivo wireless communication channel. This model will have a significant role in improving the communications performance of embedded medical devices in terms of power and spectral efficiency. In this paper, the state of the art in this field is presented to provide a comprehensive understanding of current models, considering various communication methods, operational frequencies, and antenna design. Finally, open research areas are discussed for the future studies.Index Terms-In vivo channel characterization, in/on-body communication, wireless body area networks (WBAN), wireless implantable medical devices.

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“…A few of the publication addressed communication with the instrument inside the body, but very few research studies focused specifically on WCE. The radiation from the ingested capsule in the human intestine was tested in the frequency range of 150 MHz to 1200 MHz, and it was observed that the maximum radiation was between 450 MHz and 900 MHz and that more radiation occurred in the anterior region than in the posterior region [22]. The propagation of the electromagnetic field from the intestine was investigated for the range of frequencies from 100 MHz to 700 MHz using the homogenous model of the body and the heterogeneous model, and two unusual behaviours were observed, i.e., relatively lower attenuation above 400 MHz and dip radiation at frequencies less than 400 MHz [23].…”

Section: Introductionmentioning

confidence: 99%

The Use of a Human Body Model to Determine the Variation of Path Losses in the Human Body Channel in Wireless Capsule Endoscopy

Basar¹,

Malek²,

Juni³

et al. 2013

PIER

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Abstract-Presently, wireless capsule endoscopy (WCE) is the sole technology for inspecting the human gastrointestinal (GI) tract for diseases painlessly and in a non-invasive way. For the further development of WCE, the main concern is the development of a highspeed telemetry system that is capable of transmitting high-resolution images at a higher frame rate, which is also a concern in the use of conventional endoscopy. A vital task for such a high-speed telemetry system is to be able to determine the path loss and how it varies in a radio channel in order to calculate the proper link budget. The hostile nature of the human body's channel and the complex anatomical structure of the GI tract cause remarkable variations in path loss at different frequencies of the system as well as at capsule locations that have high impacts on the calculation of the link budget. This paper presents the path loss and its variation in terms of system frequency and location of the capsule. Along with the guideline about the optimum system frequency for WCE, we present the difference between the maximum and minimum path loss at different anatomical regions, which is the most important information in the link-margin setup for highly efficient telemetry systems in next-generation capsules. In order to investigate the path loss in the body's channel, a heterogeneous human body model was used, which is more comparable to the human body than a homogenous model. The finite integration technique (FIT) in Computer Simulation Technology's (CST's) Microwave Studio was used in the simulation. The path loss was analyzed in the frequency range of 100 MHz to 2450 MHz. The path loss was found to be saliently lower at frequencies below 900 MHz. The smallest loss was found around the frequency of 450 MHz, where the variation of path loss throughout the GI tract was 29 dB, with a minimum of −9 dB and a maximum of −38 dB. However, at 900 MHz, this variation was observed to be 38 dB, with a minimum of −10 dB and a maximum of −48 dB. For most positions of the capsule, the path loss increased rapidly after 900 MHz, reaching its peak at frequencies in the range of 1800 MHz to 2100 MHz. During examination of the lower esophageal region, the maximum peak observed was −84 dB at a frequency of 1760 MHz. The path loss was comparatively higher during examination of anatomically-complex regions, such as the upper intestine and the lower esophagus as compared to the less complex stomach and upper esophagus areas.

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Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz

Cited by 176 publications

References 19 publications

Long-Range Antenna Systems for In-Body Biotelemetry: Design Methodology and Characterization Approach

Long-Range Antenna Systems for In-Body Biotelemetry: Design Methodology and Characterization Approach

In Vivo Communications: Steps Toward the Next Generation of Implantable Devices

The Use of a Human Body Model to Determine the Variation of Path Losses in the Human Body Channel in Wireless Capsule Endoscopy

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