Measurement Dataset of Experimental In-body Optical Wireless Communication Test-bed for Research Purposes

Abstract

Abstract

Ultra-wideband (UWB) and narrowband (NB) technologies have been widely used for in-body communication systems. In recent years, there has been a growing interest among researchers in optical wireless communication (OWC) as an alternative technology for in-body communication; this trend has emerged as a response to the limitations and challenges found in UWB and NB communication technologies. Conducting an in-body OWC study using an ex-vivo approach should consider several key steps. Initially, a standardized test-bed must be prepared; this involves developing it step-by-step with commercial off-the-shelf components (COTS), followed by a thorough characterization/assesment of its performance. This data-in-brief paper provides a set of measurement data obtained from a developed test-bed for in-body OWC research based on phantom and ex-vivo samples. The methodology used for data collection and the significance of the measurements are explained. The test-bed employed two receiver (Rx) devices representing an in-body device, namely 1) a photodetector module and 2) an optical sensor connected to an optical power meter console, where both devices are created by the same company (i.e., Thorlabs). The data includes the results of three measurement scenarios, namely 1) free-space channel (baseline case), 2) tissue-mimicking optical phantoms, and 3) biological tissue channels based on ex-vivo samples of fresh pork meat of different compositions. The uniqueness of this test-bed lies in its use of a photodetector module to serve as an optical power meter and then comparing the result to the optical power meter readings under three measurement scenarios (i.e., free-space, phantoms, and biological tissue samples). In addition to its primary role of converting information signals in the optical domain into the electrical domain, the photodetector module can be used indirectly to measure optical power by using the equations outlined in the datasheet, extracting the output voltage (Vout) to determine the relative optical power. The dataset presents the impact of varying incident power of near infra-red (NIR) LED, achieved through adjustments in LED current using the LED driver module, on the received optical power measured by an optical power meter and photodetector module in a separate measurement. The influence of the photodetector’s gain setting on the received optical power read by a photodetector module is also investigated. From the top-level perspective, the developed test-bed confirms its feasibility in demonstrating in-body OWC systems. From the specific point-of-view, data obtained in this paper suggests two main findings: first, changing the photodetector’s gain can increase the Vout, but it does not affect the measured optical power based on the calculation. Gain adjustment can serve to increase the scale of Vout reading. Second, the received optical power read by the photodetector module in any gain setting is closely matched with the optical power meter reading set to approximately –4.30 dB. In this sense, multiplication should be considered to align the results of optical power readings between the photodetector module and the optical power meter when using them in the experiment at the free-space and ex-vivo settings, which is around 2.7×. Future use of the provided data is intended for researchers in the biomedical engineering field, particularly those focusing on in-body OWC and dealing with ex-vivo experiments. This dataset paper can facilitate the procedure of developing and testing an in-body OWC system on a laboratory scale using the standardized test-bed, providing inspiration to researchers in this area who wish to use a similar setting with comparable instruments.