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Compressed sensing

Jeevan K Pant, Sridhar Krishnan
OBJECTIVE: To present a new compressive sensing (CS)-based method for the acquisition of ECG signals and for robust estimation of heart-rate variability (HRV) parameters from compressively sensed measurements with high compression ratio. APPROACH: CS is used in the biosensor to compress the ECG signal. Estimation of the locations of QRS segments is carried out by applying two algorithms on the compressed measurements. The first algorithm reconstructs the ECG signal by enforcing a block-sparse structure on the first-order difference of the signal, so the transient QRS segments are significantly emphasized on the first-order difference of the signal...
March 15, 2018: Physiological Measurement
Pei Huang, Yuanqing Li, Xiao-Guang Yu, Wei-Bin Zhu, Shu-Yan Nie, Hao Zhang, Jin-Rui Liu, Ning Hu, Shao-Yun Fu
The mimicry of human skin to detect both oncoming and physical-contacting object is of great importance in the fields of manufacturing, artificial robots and vehicles, etc. Herein, a novel bio-inspired flexible and highly responsive dual-mode strain/magnetism composite sensor which works via both contact and contactless modes, is first fabricated by incorporating Fe3O4/silicone system into a carbon fiber aerogel. The distance-dependence of magnetic field endorses the CFA/Fe3O4/silicone composite possible for spatial sensing due to the introduction of Fe3O4 magnetic nanoparticles...
March 15, 2018: ACS Applied Materials & Interfaces
Lining Ju, James D McFadyen, Saheb Al-Daher, Imala Alwis, Yunfeng Chen, Lotte L Tønnesen, Sophie Maiocchi, Brianna Coulter, Anna C Calkin, Eric I Felner, Neale Cohen, Yuping Yuan, Simone M Schoenwaelder, Mark E Cooper, Cheng Zhu, Shaun P Jackson
Diabetes is associated with an exaggerated platelet thrombotic response at sites of vascular injury. Biomechanical forces regulate platelet activation, although the impact of diabetes on this process remains ill-defined. Using a biomembrane force probe (BFP), we demonstrate that compressive force activates integrin αIIb β3 on discoid diabetic platelets, increasing its association rate with immobilized fibrinogen. This compressive force-induced integrin activation is calcium and PI 3-kinase dependent, resulting in enhanced integrin affinity maturation and exaggerated shear-dependent platelet adhesion...
March 14, 2018: Nature Communications
Metin Aktas, Murat Kuscu, Ergin Dinc, Ozgur B Akan
Spatial correlation between densely deployed sensor nodes in a wireless sensor network (WSN) can be exploited to reduce the power consumption through a proper source coding mechanism such as distributed source coding (DSC). In this paper, we propose the Decoding Delay-based Distributed Source Coding (D-DSC) to improve the energy efficiency of the classical DSC by employing the decoding delay concept which enables the use of the maximum correlated portion of sensor samples during the event estimation. In D-DSC, network is partitioned into clusters, where the clusterheads communicate their uncompressed samples carrying the side information, and the cluster members send their compressed samples...
2018: PloS One
Yingxuan Chen, Fang-Fang Yin, Yawei Zhang, You Zhang, Lei Ren
Compressed sensing reconstruction using total variation (TV) tends to over-smooth the edge information by uniformly penalizing the image gradient. The goal of this study is to develop a novel prior contour based TV (PCTV) method to enhance the edge information in compressed sensing reconstruction for CBCT. 
 Methods: The edge information is extracted from prior planning-CT via edge detection. Prior CT is first registered with on-board CBCT reconstructed with TV method through rigid or deformable registration...
March 14, 2018: Physics in Medicine and Biology
Davood Mardani, H Esat Kondakci, Lane Martin, Ayman F Abouraddy, George K Atia
Compressive sensing (CS) combines data acquisition with compression coding to reduce the number of measurements required to reconstruct a sparse signal. In optics, this usually takes the form of projecting the field onto sequences of random spatial patterns that are selected from an appropriate random ensemble. We show here that CS can be exploited in 'native' optics hardware without introducing added components. Specifically, we show that random sub-Nyquist sampling of an interferogram suffices to reconstruct the field modal structure despite the structural constraints of the measurement system set by its limited degrees of freedom...
March 5, 2018: Optics Express
Alexandre Rodrigues Farias, Daniel de Castro Medeiros, Hermes Aguiar Magalhães, Márcio Flávio Dutra Moraes, Eduardo M A M Mendes
PURPOSE: To combine the technique of respiratory gating and compressed sensing (CS) with the objective of accelerating mouse abdominal magnetic resonance imaging (MRI). MATERIALS AND METHODS: To obtain the maximum acceleration, phase-encoding data from a phantom and mouse were obtained on a 4.7 Tesla scanner using the respiratory gating technique. The fully sampled data (FSD) were used to construct reference images and to provide samples to simulate retrospective undersampled data (UD) acquisition using respiratory gating...
March 8, 2018: Magnetic Resonance Imaging
Trixi von Schlippenbach, Peter J Oefner, Wolfram Gronwald
Non-uniform sampling (NUS) allows the accelerated acquisition of multidimensional NMR spectra. The aim of this contribution was the systematic evaluation of the impact of various quantitative NUS parameters on the accuracy and precision of 2D NMR measurements of urinary metabolites. Urine aliquots spiked with varying concentrations (15.6-500.0 µM) of tryptophan, tyrosine, glutamine, glutamic acid, lactic acid, and threonine, which can only be resolved fully by 2D NMR, were used to assess the influence of the sampling scheme, reconstruction algorithm, amount of omitted data points, and seed value on the quantitative performance of NUS in1 H,1 H-TOCSY and1 H,1 H-COSY45 NMR spectroscopy...
March 9, 2018: Scientific Reports
Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini
The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation...
March 9, 2018: Sensors
Julien Fade, Estéban Perrotin, Jérôme Bobin
We propose an original concept of compressive sensing (CS) polarimetric imaging based on a digital micromirror (DMD) array and two single-pixel detectors, without using any polarizer. The polarimetric sensitivity of the proposed setup is due to the tiny difference in Fresnel's coefficients of reflecting mirrors, which is exploited here to form an original reconstruction problem including a CS problem and a source-separation task. We show that a two-step approach, tackling each problem successively, is outperformed by a dedicated combined reconstruction method, which is demonstrated in this paper and preferably implemented through a reweighted fast iterative shrinkage-thresholding algorithm...
March 1, 2018: Applied Optics
Ajin Joy, Joseph Suresh Paul
PURPOSE: Avoid formation of staircase artifacts in nonlinear diffusion-based MR image reconstruction without compromising computational speed. METHODS: Whereas second-order diffusion encourages the evolution of pixel neighborhood with uniform intensities, fourth-order diffusion considers smooth region to be not necessarily a uniform intensity region but also a planar region. Therefore, a controlled application of fourth-order diffusivity function is used to encourage second-order diffusion to reconstruct the smooth regions of the image as a plane rather than a group of blocks, while not being strong enough to introduce the undesirable speckle effect...
March 7, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Conor S Boland, Umar Khan, Mathew Binions, Sebastian Barwich, John B Boland, Denis Weaire, Jonathan N Coleman
The use of graphene-based nanocomposites as electromechanical sensors has been broadly explored in recent times with a number of papers describing porous, foam-like composites. However, there are no reported foam-based materials that are capable of large dynamic compressive load measurements and very few studies on composite impact sensing. In this work, we describe a simple method of infusing commercially-available foams with pristine graphene to form conductive composites, which we refer to as G-foam. Displaying a strain-dependent electrical response, G-foam was found to be a reasonably effective pressure sensing material...
March 6, 2018: Nanoscale
Xue Feng, Silvia S Blemker, Josh Inouye, Catherine M Pelland, Li Zhao, Craig H Meyer
PURPOSE: To develop a real-time dynamic MRI method for comprehensive evaluation of velum movement during speech. METHODS: Dynamic MRI has been used to study velopharyngeal insufficiency (VPI) by imaging the movement of the velum during speech, because it can provide good anatomic details with no exposed radiation. To be able to comprehensively evaluate dynamic velum movement, a real-time spiral non-balanced SSFP sequence was developed with simultaneous dual-planar coverage and improved spatial and temporal resolution using a combination of parallel imaging and spatial and temporal compressed sensing to achieve 6 × acceleration...
March 5, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Valentina Mazzoli, Lukas M Gottwald, Eva S Peper, Martijn Froeling, Bram F Coolen, Nico Verdonschot, Andre M Sprengers, Pim van Ooij, Gustav J Strijkers, Aart J Nederveen
PURPOSE: 3D time-resolved (4D) phase contrast MRI can be used to study muscle contraction. However, 3D coverage with sufficient spatiotemporal resolution can only be achieved by interleaved acquisitions during many repetitions of the motion task, resulting in long scan times. The aim of this study was to develop a compressed sensing accelerated 4D phase contrast MRI technique for quantification of velocities and strain rate of the muscles in the lower leg during active plantarflexion/dorsiflexion...
March 5, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Adrien Besson, Dimitris Perdios, Florian Martinez, Zhouye Chen, Rafael E Carrillo, Marcel Arditi, Yves Wiaux, Jean-Philippe Thiran
Conventional ultrasound (US) image reconstruction methods rely on delay-and-sum (DAS) beamforming, which is a relatively poor solution to the image reconstruction problem. An alternative to DAS consists in using iterative techniques, which require both an accurate measurement model and a strong prior on the image under scrutiny. Toward this goal, much effort has been deployed in formulating models for US imaging, which usually require a large amount of memory to store the matrix coefficients. We present two different techniques, which take advantage of fast and matrix-free formulations derived for the measurement model and its adjoint, and rely on sparsity of US images in well-chosen models...
March 2018: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Colas Schretter, Shaun Bundervoet, David Blinder, Ann Dooms, Jan D'hooge, Peter Schelkens
Upcoming phased-array 2-D sensors will soon enable fast high-definition 3-D ultrasound imaging. Currently, the communication of raw radio-frequency (RF) channel data from the probe to the computer for digital beamforming is a bottleneck. For reducing the amount of transferred data samples, this paper investigates the design of an adapted sparse sampling technique for image reconstruction inspired by the compressed sensing framework. Echo responses from isolated points are generated using a physically based simulation of ultrasound wave propagation through tissues...
March 2018: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Chen Song, Aosen Wang, Feng Lin, Mohammadnabi Asmani, Ruogang Zhao, Zhanpeng Jin, Jian Xiao, Wenyao Xu
As a micro-engineered biomimetic system to replicate key functions of living organs, organ-on-a-chip (OC) technology provides a high-throughput model for investigating complex cell interactions with both high temporal and spatial resolutions in biological studies. Typically, microscopy and high-speed video cameras are used for data acquisition, which are expensive and bulky. Recently, compressed sensing (CS) has increasingly attracted attentions due to its extremely low-complexity structure and low sampling rate...
March 2018: IEEE Journal of Biomedical and Health Informatics
Myung Cho, Kumar Vijay Mishra, Weiyu Xu
The null space condition for ℓ 1 minimization in compressed sensing is a necessary and sufficient condition on the sensing matrices under which a sparse signal can be uniquely recovered from the observation data via ℓ 1 minimization. However, verifying the null space condition is known to be computationally challenging. Most of the existing methods can provide only upper and lower bounds on the proportion parameter that characterizes the null space condition. In this paper, we propose new polynomial-time algorithms to establish upper bounds of the proportion parameter...
2018: EURASIP Journal on Advances in Signal Processing
Sunghoon Choi, Haenghwa Lee, Donghoon Lee, Seungyeon Choi, Chang-Lae Lee, Woocheol Kwon, Jungwook Shin, Chang-Woo Seo, Hee-Joung Kim
PURPOSE: This work describes the hardware and software developments of a prototype chest digital tomosynthesis (CDT) R/F system. The purpose of this study is to validate the developed system for its possible clinical application on low-dose chest tomosynthesis imaging. METHODS: The prototype CDT R/F system was operated by carefully controlling the electromechanical subsystems through a synchronized interface. Once a command signal was delivered by the user, a tomosynthesis sweep started to acquire 81 projection views (PVs) in a limited angular range of ±20°...
March 3, 2018: Medical Physics
Minxuan Xu, Junjie Qi, Feng Li, Yue Zhang
Strain sensors with high sensitivity, broad sensing ranges and excellent durable stability are highly desirable due to their promising potential in electronic skins and human-friendly wearable interactive systems. Herein, we report a high-performance strain sensor based on rGO (reduced graphene oxide)/DI (deionized water) sensing elements. The strain sensors were fabricated by using Ecoflex rubber filled with rGO/DI conductive liquids via template methods, making the process simple, low-cost and scalable. The as-assembled strain sensors can be used to reflect both stretching and compressing with high sensitivity (a maximum gauge factor of 31...
March 2, 2018: Nanoscale
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