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

Abstract

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.

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

“…For the sake of brevity a brief summary of the implemented phantom-based measurements setup ( Figure 1) is given here. A more detailed description of the experimental testbed can be found in [18]. The primary components of the measurement setup are: an anechoic chamber, a Vector Network Analyzer (VNA), a three-dimensional automatic positioner, a two-layer plastic phantom container and a magnetic tracker.…”

Initial Delay Domain UWB Channel Characterization for In-Body Area Networks

“…On the other hand, this manuscript extracts the delay characteristics from the laboratory measurements and then these experimental measurements are compared with software simulations. Moreover, a previous characterization in frequency domain was performed in [6], [7], obtaining a formula for the system loss of the radio budget link for the low UWB frequency band (3.1 to 5.1 GHz). In previous, works the comparison between software simulations, phantom measurements and in vivo measurements showed a high level of agreement in frequency domain achieving very similar system loss model.…”

Location and Tracking for Ultra-WideBand In-Body Communications in Medical Applications

“…Within a collaboration between the UPV and the Dresden University of Technology (TUD) experimental measurements were carried out at UPV facilities with the aim of comparing dierent on-body receiving antennas [69]. The setup was developed at UPV specically for IB2OB measurements [70] and it is shown in Figure 3.9. The main novel components, besides the VNA and the 3D cartesian positioner described in Section 3.2.2.2.1, are an anechoic chamber and a magnetic tracker.…”

“…Experimental measurements, using a multilayer phantom-based setup were conducted at the UPV facilities. A novel two-layer phantom container (element 5 in Figure 3.13) has been designed to more precisely emulate the complex human body environment involved in WCE applications [70]. The container is made of Polyethylene terephthalate (PET) of 1.5 mm width and has an overall internal volume of 25x25x25 cm 3 with two layers.…”

“…GHz were below the noise level[70]. Path loss values related to antennas distances below or equal to 8 cm were tted through Equa-tion 3.2, resulting P L 0,d ref = 21.84 dB and n = 5.44, considering a reference distance of d ref = 1 cm.…”