Localization for capsule endoscopy at UWB frequencies using an experimental multilayer phantom

IEEE Trans. Antennas Propagat.

Nevárez

et al. 2019

Self Cite

In recent years, localization for capsule endoscopy applications using Ultra-Wideband (UWB) technology has become an attractive field of investigation due to its potential benefits for patients. Literature concerning performance analysis of RF-based localization techniques for in-body applications at UWB frequencies is very limited. Available studies mainly rely on Finite Difference Time Domain (FDTD) simulations, using digital human models and on experimental measurements by means of homogeneous phantoms. Nevertheless, no realistic analysis based on multilayer phantom measurements or through in vivo experiment has been reported yet. This paper investigates the performance of RSS-based approach for two-dimensional (2D) and three-dimensional localization (3D) in the UWB frequency band. For 2D localization, experimental laboratory measurements using a two-layer phantom based setup have been conducted. For 3D localization, data from a recently conducted in vivo experiment have been used. Localization accuracy using path loss (PL) models, under ideal and not ideal channel estimation assumptions, are compared. Results show that under not ideal channel assumption the relative localization error slightly increases for the 2D case but not for the in vivo 3D case. Impact of receivers selection on the localization accuracy has also been investigated for both, 2D and 3D, cases. Index Terms-Wireless capsule endoscopy (WCE), Ultra-Wideband (UWB), in-body localization, heterogeneous phantom, in vivo measurements.

Section: B 2d Localization Resultssupporting

confidence: 67%

“…3). In order to estimate the in-body antenna coordinates the adaptive linearized method described in [31] is adapted [32] and implemented for the two dimensional case. Three receivers are needed to find the unique solution of the linearized system of two equations in two unknowns.…”

Section: A 2d Phantom-based Post-processingmentioning

confidence: 99%

UWB RSS-Based Localization for Capsule Endoscopy Using a Multilayer Phantom and In Vivo Measurements

IEEE Trans. Antennas Propagat.

Nevárez

et al. 2019

Self Cite

“…Ranging distance estimation is performed as in [23] by using the log-distance path loss model evaluated from the measured 21 S , for each in-body to on-body antenna position. Then, the coordinates of the in-body antenna are estimated using the Non Linear Least Square method described in [24].…”

Section: Rss-based Localization Algorithmmentioning

confidence: 99%

Impact of Receivers Location on the Accuracy of Capsule Endoscope Localization

2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

Cardona

et al. 2018

Self Cite

In recent years, localization for capsule endoscopy applications using Ultra-Wideband (UWB) technology has become an attractive field of study due to its potential benefits for patients. Performance analysis of RF-based localization techniques are very limited in literature. Most of the available studies rely on software simulations using digital human models. Nonetheless, no realistic studies based on in-vivo measurements has been reported yet. This paper investigates the performance of RSS-based technique for three-dimensional (3D) localization in the UWB frequency band. Impact of receivers selection as well as of the evaluated path loss model on the localization accuracy is investigated. Results obtained through CST-based simulations and from recently conducted in-vivo measurements are presented and compared.

“…Measured reflection coefficients of the transmitting and the receiving antennas inside muscle phantom Measurement Grid Setup[18].…”

mentioning

confidence: 99%

Initial UWB in-body channel characterization using a novel multilayer phantom measurement setup

Perez-Simbor

2018 IEEE Wireless Communications and Networking Conference Workshops (WCNCW)

et al. 2018

Self Cite

Wireless Body Area Networks (WBANs) are a promising technology for medical purposes. Currently the WBAN are classified into: implanted (in-), surface (on-) or outside (off-) body communications regarding the location of the devices with reference to the human body. The Ultra Wide-Band (UWB) frequency band is growing as a band of interest for implanted communications because of its high data rate and low power consumption among other benefits. Software simulations, in-vivo measurements and experimental phantom measurements are common methods to properly characterize the propagation channel. Nevertheless, up to now, experimental phantoms measurements presented in the literature show some inconveniences, i.e., the accuracy of the phantoms compared with the real human tissues or the testbed used for the measurements. This paper aims at overcoming these issues using accurate phantoms designed for the purpose of implanted communications in the UWB frequency band. In addition, a multilayer phantom container was developed. This container has capacity for two different phantoms, emulating a heterogeneous propagation medium for in-body measurements. Moreover, a novel setup was built for in-body phantom measurements. As a result, an experimental path loss model is presented from the measurements obtained with phantoms. Besides, software simulations mimicking the experimental setup are performed in order to validate the previous results obtained.