Diffuse transmitted spectroscopy in conjunction with spectral peak averaging as a potential tool for noninvasive creatinine screening

Creatinine(Cr)is a biochemical waste molecule generated from muscle metabolism and primarily cleared from the bloodstream by the kidneys.If kidney function declines,Cr levels in the blood tend to increase.Therefore,Cr serves as an indicator of kidney function.In this work,we present a simple method for the rapid screening for impaired renal function based on the subject's Cr concentration.In our setup,broadband white light is delivered to a finger clamp through a fiber-optic cable to illuminate the patient's finger.The light is transmitted through the finger and collected by a second optical fiber coupled to a visible-near-infrared(VisNIR)spectrometer which covers the spectral range from 400nm to 1100nm.During the calibration process,the transmitted spectra acquired from 60 patients were measured.An average was calculated using the peak level of the transmitted,diffused intensity at three different wavelengths to create a"Cr intensity index".Patients were divided into five groups according to their Cr concentration levels,ranging from 1 mg/dL to 13 mg/dL.Our observations indicated that each group featured a unique spectral fingerprint.Next,we tested the index on 20 patients not included in the cali-bration procedure(unknown samples).We were able to classify patients into groups according to their Cr level with moderate prediction accuracy(R^(2)=0.55)and mean screening error of up to 16%.Future efforts will evaluate the accuracy of this approach with larger patient populations representing a broad range of Cr concentration.Still,this preliminary work is an essential step toward developing this useful noninvasive Cr screening platform using NIR light spectroscopy.

A Joint Rate Control and AMC Algorithm for Adaptive Transmission Systems

The traditional communication system is effectively designed for the worst-case channel state and it can not use the spectral efficiently over the time-varying multipath channel. In order to improve the spectral efficiency and ensure robust and spectrally-efficient transmission over the time-varying multipath channel,a joint rate control and adaptive modulation and coding ( AMC) algorithm for adaptive transmission systems is proposed in this paper. Firstly,the proposed algorithm can formulate a modulation and coding scheme ( MCS) switching table according to the offline simulation results and the target bit error rate ( BER) . Then,the optimal MCS is selected in MCS switching table according to the channel state information ( CSI) and then passes to the transmitter and receiver to implement. So the adaptive system which always uses the optimal MCS to transmit signals uses the spectral efficiently. The simulation results validate the proposed algorithm and show that under the premise of meeting the target BER,the adaptive system performing the proposed algorithm has a higher average spectral efficiency ( ASE) than that of the non-adaptive system.

On Broadband Adaptive Beamforming in the Presence of Correlated Interferences

A novel approach of unitarily interpolated array MVDR （UIA-MVDR） is proposed, aiming at avoiding the signal cancellation caused by broadband signal-correlated interferences. UIA-MVDR belongs to the classic approaches of spectral averaging. However, it is distinguished from the conventional interpolated array MVDR （IA-MVDR） by two points： 1） It imposes a unitary constraint on the transform matrices. 2） It only optimizes the worst-case performance of array manifold approximation. As a result, the restriction on the order of Bessel function expansion is released, so that very accurate approximation can be achieved even in the case of small or middle arrays. Compared with many related approaches, UIA-MVDR destroys the correlation more completely and then achieves better performance. Its excellent performance in both correlated and uncorrelated broadband interferences suppression is confirmed via a n umber of numerical examples.