Prototype of an opto-capacitive probe for non-invasive sensing cerebrospinal fluid circulation

In brain studies, the function of the cerebrospinal fluid (CSF) awakes growing interest, particularly related to studies of the glymphatic system in the brain, which is connected with the complex system of lymphatic vessels responsible for cleaning the tissues. The CSF is a clear, colourless liquid including water (H2O) approximately with a concentration of 99 %. In addition, it contains electrolytes, amino acids, glucose, and other small molecules found in plasma. The CSF acts as a cushion behind the skull, providing basic mechanical as well as immunological protection to the brain. Disturbances of the CSF circulation have been linked to several brain related medical disorders, such as dementia. Our goal is to develop an in vivo method for the non-invasive measurement of cerebral blood flow and CSF circulation by exploiting optical and capacitive sensing techniques simultaneously. We introduce a prototype of a wearable probe that is aimed to be used for long-term brain monitoring purposes, especially focusing on studies of the glymphatic system. In this method, changes in cerebral blood flow, particularly oxy- and deoxyhaemoglobin, are measured simultaneously and analysed with the response gathered by the capacitive sensor in order to distinct the dynamics of the CSF circulation behind the skull. Presented prototype probe is tested by measuring liquid flows inside phantoms mimicking the CSF circulation

On the TDD subframe structure for beyond 4G radio access network

The purpose of a Beyond 4G (B4G) radio access technology, is to cope with the expected exponential increase of mobile data traffic in local area (LA). The requirements related to physical layer control signaling latencies and to hybrid ARQ (HARQ) round trip time (RTT) are in the order of ~1ms. In this paper, we propose a flexible orthogonal frequency division multiplexing (OFDM) based time division duplex (TDD) physical subframe structure optimized for B4G LA environment. We show that the proposed optimizations allow very frequent link direction switching, thus reaching the tight B4G HARQ RTT requirement and significant control signaling latency reductions compared to existing LTE-Advanced and WiMAX technologies

A cooperative moving relay node system deployment in a high speed train

Abstract-In this paper we present system level simulation results for a cooperative moving relay node (MRN) system deployed on a high speed train (HST). Recently interest has grown in using MRNs to provide enhanced cellular coverage to users in public transport, particularly HSTs, of which the modern construction materials and techniques cause high vehicle penetration loss (VPL) when signals propagate into the train. MRNs utilising antenna arrays on the exterior and interior of the train are a promising solution to overcoming this VPL in order to provide onboard users with improved service. We show that a cooperative system of 8 MRNs onboard a HST is able to provide significant improvements to achievable throughput of onboard users when compared to direct transmission, as well as indirectly improving the throughput of other users located in cells the HST is passing through

Efficient Fast-Convolution Implementation of Filtered CP-OFDM Waveform Processing for 5G

© 2015 IEEE.This paper investigates the use of effective and flexible fast-convolution (FC) filtering scheme for multiplexing OFDM resource blocks (RBs) in a spectrally well-localized manner. The scheme is able to effectively suppress interference leakage between adjacent RBs, thus supporting asynchronous operation and independent waveform parametrization of RBs. This is considered as an important feature in 5G waveform development for effectively supporting diversified service characteristics. Our approach is applicable for cyclic prefix or zero prefix based OFDM and the corresponding OFDM based singlecarrier (SC-FDMA) waveforms. It is also possible to generate and process traditional Nyquist pulse shaping based single-carrier waveforms and filter bank multicarrier waveforms using the same FC processing engine, accommodating different waveforms simultaneously in different RBs. Our case study is based on proposed numerology for 5G cm-wave communications utilizing flexible time-division duplexing principle. While using RBs of 160 OFDM subcarriers, it is enough to deactivate 3 to 5 subcarriers out of each RB as guardbands to effectively suppress interference leakage between RBs.acceptedVersionPeer reviewe