Showing papers by "Philips published in 2013"
TL;DR: This work presents an analysis of the motion problem, from which far superior chrominance-based methods emerge, and shows remote photoplethysmography methods to perform in 92% good agreement with contact PPG, with RMSE and standard deviation both a factor of 2 better than BSS- based methods.
Abstract: Remote photoplethysmography (rPPG) enables contactless monitoring of the blood volume pulse using a regular camera. Recent research focused on improved motion robustness, but the proposed blind source separation techniques (BSS) in RGB color space show limited success. We present an analysis of the motion problem, from which far superior chrominance-based methods emerge. For a population of 117 stationary subjects, we show our methods to perform in 92% good agreement (±1.96σ) with contact PPG, with RMSE and standard deviation both a factor of 2 better than BSS-based methods. In a fitness setting using a simple spectral peak detector, the obtained pulse-rate for modest motion (bike) improves from 79% to 98% correct, and for vigorous motion (stepping) from less than 11% to more than 48% correct. We expect the greatly improved robustness to considerably widen the application scope of the technology.
844 citations
TL;DR: MRI/US-fusion-guided biopsy upgrades and detects PCa of higher Gleason score in 32% of patients compared with traditional 12-core biopsy alone, and preferentially detects higher-grade PCa while missing lower-grade tumors.
460 citations
TL;DR: This study demonstrates that native and post-contrast T1 values provide indexes with high diagnostic accuracy for the discrimination of normal and diffusely diseased myocardium.
Abstract: Objectives: The aim of this study was to examine the value of native and post-contrast T1 relaxation in the differentiation between healthy and diffusely diseased myocardium in 2 model conditions, ...
414 citations
TL;DR: These findings emphasize an imperative to support the enforcement capacity in low-income countries, in which risk of biodiversity loss is exceptionally high, and solutions for greater resilience of sea cucumber stocks must be embedded within those for poverty reduction and alternative livelihood options.
Abstract: Worldwide, most sea cucumber fisheries are ineffectively managed, leading to declining stocks and potentially eroding the resilience of fisheries. We analyse trends in catches, fishery status, fishing participation and regulatory measures among 77 sea cucumber fisheries through data from recent fishery reports and fishery managers. Critical gaps in fisheries biology knowledge of even commonly targeted species undermine the expected success of management strategies. Most tropical fisheries are small-scale, older and typified by numerous (>8) species, whereas temperate fisheries are often emerging, mono-specific and industrialized. Fisher participation data indicated about 3 million sea cucumber fishers worldwide. Fisher participation rates were significantly related to the average annual yield. permanova analysis showed that over-exploited and depleted fisheries employed different sets of measures than fisheries with healthier stocks, and a non-metric multidimensional scaling ordination illustrated that a broad set of regulatory measures typified sustainable fisheries. SIMPER and regression tree analyses identified that the dissimilarity was most related to enforcement capacity, number of species harvested, fleet (vessel) controls, limited entry controls and rotational closures. The national Human Development Index was significantly lower in countries with over-exploited and depleted fisheries. Where possible, managers should limit the number of fishers and vessel size and establish short lists of permissible commercial species in multispecies fisheries. Our findings emphasize an imperative to support the enforcement capacity in low-income countries, in which risk of biodiversity loss is exceptionally high. Solutions for greater resilience of sea cucumber stocks must be embedded within those for poverty reduction and alternative livelihood options.
379 citations
TL;DR: It is shown that smooth neat PVDF films can be made at elevated substrate temperature, and the replacement of P(VDF-TrFE) by the commodity polymer PVDF may boost large-scale industrial applications.
Abstract: Although poly(vinylidene fluoride) is a well-known organic ferroelectric, its utilization in microelectronics has been hampered by the difficulty in obtaining uniform thin films. By exploiting a high-temperature deposition approach, smooth and thin films of the ferroelectric δ-phase polymorph of this material are now obtained, showing their potential for capacitors and non-volatile memories.
347 citations
TL;DR: In this article, the authors give an overview on the recent process of the development of nanotechnology and nanowire-based gas sensors and compare two basic approaches, top-down and bottom-up, for synthesizing nanowires.
Abstract: Gas sensors fabricated with nanowires as the detecting elements are powerful due to their many improved characteristics such as high surface-to-volume ratios, ultrasensitivity, higher selectivity, low power consumption, and fast response. This paper gives an overview on the recent process of the development of nanotechnology and nanowire-based gas sensors. The two basic approaches, top-down and bottom-up, for synthesizing nanowires are compared. The conduction mechanisms, sensing performances, configurations, and sensing principles of different nanowire gas sensors and arrays are summarized and discussed. Meanwhile, an emerging nanowires fabrication method and a self-powered nanowire pH sensor are highlighted. The scientific and technological challenges in the field are discussed at the end of the review. © 2012 Elsevier B.V. All rights reserved.
346 citations
TL;DR: In this article, a large improvement in solid-state lighting emission was achieved by coupling emitters with very high intrinsic quantum efficiency (QE) to collective plasmonic resonances in periodic arrays of aluminum nanoantennas.
Abstract: Light sources based on reliable and energy-efficient light-emitting diodes (LEDs) are instrumental in the development of solid-state lighting (SSL). Most research efforts in SSL have focused on improving both the intrinsic quantum efficiency (QE) and the stability of light emitters. For this reason, it is broadly accepted that with the advent of highly efficient (QE close to 1) and stable emitters, the fundamentalresearchphaseofSSLiscomingtoanend.Inthisstudy,wedemonstrateaverylargeimprovementinSSLemission(above 70-fold directional enhancement for p-polarized emission and 60-fold enhancement for unpolarized emission) using nanophotonic structures. This is attained by coupling emitters with very high QE to collective plasmonic resonances in periodic arrays of aluminum nanoantennas.OurresultsopenanewpathforfundamentalandappliedresearchinSSLinwhichplasmonicnanostructuresareableto mold the spectral and angular distribution of the emission with unprecedented precision. Light: Science & Applications (2013) 2, e66; doi:10.1038/lsa.2013.22; published online 10 May 2013
341 citations
TL;DR: There was a large variability in accelerometer output and their validity to assess daily physical activity and there is little evidence that adding other physiological measures such as heart rate significantly improves the estimation of energy expenditure.
Abstract: The field of application of accelerometry is diverse and ever expanding. Because by definition all physical activities lead to energy expenditure, the doubly labelled water (DLW) method as gold standard to assess total energy expenditure over longer periods of time is the method of choice to validate accelerometers in their ability to assess daily physical activities. The aim of this paper was to provide a systematic overview of all recent (2007-2011) accelerometer validation studies using DLW as the reference. The PubMed Central database was searched using the following keywords: doubly or double labelled or labeled water in combination with accelerometer, accelerometry, motion sensor, or activity monitor. Limits were set to include articles from 2007 to 2011, as earlier publications were covered in a previous review. In total, 38 articles were identified, of which 25 were selected to contain sufficient new data. Eighteen different accelerometers were validated. There was a large variability in accelerometer output and their validity to assess daily physical activity. Activity type recognition has great potential to improve the assessment of physical activity-related health outcomes. So far, there is little evidence that adding other physiological measures such as heart rate significantly improves the estimation of energy expenditure.
295 citations
TL;DR: The state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery is reviewed and the technical challenges and future perspectives towards clinical translation are discussed.
292 citations
TL;DR: By incorporation of aluminum or arsenic in the GaP nanowires, the emitted wavelength is tuned across an important range of the visible light spectrum (555–690 nm), which enables new pathways to tailor materials properties enhancing the functionality.
Abstract: The main challenge for light-emitting diodes is to increase the efficiency in the green part of the spectrum. Gallium phosphide (GaP) with the normal cubic crystal structure has an indirect band gap, which severely limits the green emission efficiency. Band structure calculations have predicted a direct band gap for wurtzite GaP. Here, we report the fabrication of GaP nanowires with pure hexagonal crystal structure and demonstrate the direct nature of the band gap. We observe strong photoluminescence at a wavelength of 594 nm with short lifetime, typical for a direct band gap. Furthermore, by incorporation of aluminum or arsenic in the GaP nanowires, the emitted wavelength is tuned across an important range of the visible light spectrum (555–690 nm). This approach of crystal structure engineering enables new pathways to tailor materials properties enhancing the functionality.
290 citations
Patent•
26 Jul 2013TL;DR: In this article, a working chamber (31) capable of housing ingredients in operation of the device, comprising an extrusion die (120), a rotation shaft (32), and a driving system (64) by which the rotation shaft is driven.
Abstract: A device (1) for preparing extrudable food products, comprising a working chamber (31) capable of housing ingredients in operation of the device(1); an extrusion die (120); a rotation shaft (32) configured for stirring the ingredients and extruding the food products through the extrusion die (120); and a driving system (64) by which the rotation shaft (32) is driven; wherein the driving system (64) is configured to separate the extrusion by at least one time period during which the rotation shaft rotates in a first direction which is opposite to a second direction in which the rotation shaft (32) rotates to extrude the food products. Therefore build- ups inside the working chamber (31) can be possibly removed by the sticky dough hit/lifted by the stirring bars (321) on the rotation shaft (32) when the rotation shaft (32) rotates reversely.
TL;DR: First data on a tumor patient show reduction in both relayed NOE and CEST amid proton signals leading to an increase in magnetization transfer ratio asymmetry, providing insight into previously reported amide proton transfer (APT) effects in tumors.
Patent•
20 Jun 2013TL;DR: In this paper, a wireless power transfer system includes a power receiver (105) and a power transmitter (101) generating a wireless inductive power transfer signal for powering the power receiver during a power transfer phase.
Abstract: A wireless power transfer system includes a power receiver (105) and a power transmitter (101) generating a wireless inductive power transfer signal for powering the power receiver (105) during a power transfer phase. An apparatus, often the power transmitter (101) comprises a first communication unit (305) communicating with a second communication unit of an entity using an electromagnetic communication signal. The entity may typically be the power receiver (105). The apparatus comprises a reference processor (307) for measuring and storing a reference value of a characteristic of the communication signal and a measurement unit (309) which repeatedly during the power transfer phase determines a measured value of the characteristic. A comparator (311) compares the measured values to the reference value and an initiator (313) triggers an entity detection process if the comparison indicates that a measured value and the reference value do not meet a similarity criterion. The entity detection process detect a presence of another entity.
Patent•
14 Mar 2013TL;DR: In this paper, an adaptive power receiver can be switched among two or more modes of operation, including, for example, a high Q mode and a low Q mode, by controlling the switching between modes, the amount of energy received by the adaptive receiver may be controlled.
Abstract: A remote device in accordance with the present invention includes an adaptive power receiver that receives wireless power from the wireless power supply by induction. The adaptive power receiver may be switched among two or more modes of operation, including, for example, a high-Q mode and a low-Q mode. By controlling the switching between modes, the amount of energy received by the adaptive receiver may be controlled. This control is a form of adaptive resonance control or Q control.
Patent•
22 Oct 2013TL;DR: In this article, a lighting unit consisting of a blue light, a green light, and a red light was proposed, which was configured to provide red light with a broad band spectral light distribution.
Abstract: The invention provides a lighting unit comprising a source of blue light, a source of green light, a first source of red light comprising a first red luminescent material, configured to provide red light with a broad band spectral light distribution, and a second source of red light comprising a second red luminescent material, configured to provide red light with a spectral light distribution comprising one or more red emission lines. Especially, the first red luminescent material comprises (Mg,Ca,Sr)AlSiN 3 :Eu and/or (Ba,Sr,Ca) 2 Si 5 - x Al x O x N 8-x :Eu, and the second red luminescent material comprises K 2 SiF 6 :Mn.
TL;DR: This review illustrates current applications and possible future directions of 7 Tesla (7 T) Magnetic Resonance Imaging (MRI) in the field of brain MRI, in clinical studies as well as clinical practice.
TL;DR: The reactivity of the fastest bioorthogonal reaction, the inverse-electron-demand-Diels-Alder cycloaddition between a tetrazine probe and a trans-cyclooctene-tagged antibody, can be increased 10-fold, approaching the speed of biological interactions, while also increasing its stability.
TL;DR: In this paper, a camera based plethysmography was used as a contactless method to determine heart rate in the Neonatal Intensive care unit (NICU).
TL;DR: The benefits of combining conventional and bacterial cellulose with these electroactive composites are described and future applications are considered.
Abstract: Cellulose-based electroconductive composites can be prepared by combining conducting electroactive materials with hydrophilic biocompatible cellulose. Inorganic nanoparticles, such as metal ions and oxides, carbon nanotubes, graphene and graphene oxide, conducting polymers, and ionic liquids (through doping, blending or coating) can be introduced into the cellulose matrix. Such composites can form a biocompatible interface for microelectronic devices, and provide a biocompatible matrix or scaffold for electrically stimulated drug release devices, implantable biosensors, and neuronal prostheses. Here the benefits of combining conventional and bacterial cellulose with these electroactive composites are described and future applications are considered.
TL;DR: Elasticity and viscosity measured between 95 Hz and 380 Hz by using SDUV are correlated and that elasticity measurements fromSDUV and TTP showed substantially similar performance in liver fibrosis staging, although elasticity calculated from SDUV provided a better area under the ROC curve.
Abstract: Our preliminary results suggest that Voigt elasticity and viscosity measured between 95 Hz and 380 Hz by using shear wave dispersion ultrasound vibrometry (SDUV) are correlated and that the use of Voigt elasticity measurements from SDUV may not substantially improve performance in liver fibrosis staging compared with the time-to-peak method.
TL;DR: The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce(3+) are investigated as a function of the Ga/Al ratio to improve understanding of the energy flow and luminescence quenching in these materials.
Abstract: The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce(3+) are investigated as a function of the Ga/Al ratio, aimed at an improved understanding of the energy flow and luminescence quenching in these materials. A decrease of both the crystal field strength and band gap with increasing content of Ga(3+) is observed and explained by the geometrical influence of Ga(3+) on the crystal field splitting of the 5d level in line with theoretical work of Munoz-Garcia et al. ( unoz-Garcia, A. B.; Seijo, L. Phys. Rev. B 2010, 82, 184118 ). Thermal quenching results in shorter decay times as well as reduced emission intensities for all samples in the temperature range from 100 to 500 K. An activation energy for emission quenching is calculated from the data. The band gap of the host is measured upon Ga substitution and the decrease in band gap is related to Ga(3+) substitution into tetrahedral sites after all octahedral sites are occupied in the garnet material. Based on the change in band gap and crystal field splitting, band diagrams can be constructed explaining the low thermal quenching temperatures in the samples with high Ga content. The highest luminescence intensity is found for Gd3(Ga,Al)5O12 with 40% of Al(3+) replaced by Ga(3+).
TL;DR: It is critical to choose an appropriate range of b‐values in studies or include the non‐Gaussian diffusion contribution to obtain unbiased IVIM measurements and eliminate the need for DCE‐MRI, which is especially relevant in patients who cannot receive intravenous gadolinium‐based contrast media.
Abstract: Prostate cancer is the second most common cancer in American men; approximately one in six men will be diagnosed with prostate cancer during his lifetime (1). Currently, the definitive diagnosis of prostate cancer depends on histologic confirmation by prostate biopsy or surgery. Compared to conventional blind and random biopsies, Magnetic Resonance (MR) image-guided biopsies of suspicious lesions were shown with increased accuracy and yield (2). Clearly, the key to the success of this targeted biopsy is that MR images should have higher sensitivity and specificity in identifing suspicious lesions. To this end, an advanced multi-parametric (MP) MR imaging paradigm is normally employed to obtain both anatomical and functional images in order to increase the accuarcy of lesions’ detection (3).
Diffusion weighted (DW) imaging is an integral part of MP-MRI acquisition protocol. Normally, the apparent diffusion coefficient (ADC) of water molecules within living tissues is derived analytically from diffusion images with an assumption that the water molecular diffusion is a random process (4), i.e. the chance of a particular molecule diffusing from one location to another in a given time interval is solely determined by a probability distribution function, and this function has a Gaussian line-shape with its width proportional to the diffusion coefficient. This type of diffusion is also known as Gaussian diffusion characterized by a simple mono-exponential decay model.
However, the measured diffusion signals in biological tissues were not always well characterized with this simple function. Le Bihan et al. (5) demonstrated that blood microcirculation in capillary network (perfusion) was capable of altering diffusion signal intensities at very low b-values, and the intravoxel incoherent motion (IVIM) theory was proposed to account for molecular diffusion driven by thermal energy as well as perfusion-based pseudo-diffusion. On the other extreme, the water molecular diffusion in the brain and prostate would also depart from a mono-exponential function at very high b-values (6–10). It was believed that the presence of different barriers in cellular complex structures (e.g. cell membranes and organelle compartments) led to the departure from Gaussian diffusion. To quantify this non-Gaussian diffusion process, diffusion kurtosis MR imaging was developed in which the diffusion signal (in natural logarithm) was represented by a quadratic function, instead of a simple linear function for Gaussian diffusion (11).
In recent years, there has been a renewed interest in IVIM on body parts other than the brain (12–19), thanks to improved MR hardware. In particular, three studies (14–16) reported that diffusion coefficients (D) were decreased in prostate tumors compared to benign tissues, which was consistent with the literature (20); however, perfusion fractions (f) were unexpectedly lower in tumors, which is contrary to what has been known from DCE studies and angiogenesis in tumors (21–22). In these studies, the highest b-values up to 800 s/mm2 were used; and diffusion was modeled as a Gaussian diffusion. It was well documented that the deviation from Gaussian diffusion manifested in the form of a bi-exponential (i.e. fast and slow) diffusion model when using an extended range of b-values from 200 to 3000 s/mm2 in previous prostate DW studies (6–7). It is clinically relevant to obtain both diffusion and perfusion information simultaneously in an IVIM study; specifically, the perfusion information could be derived without the need for intravenous contrast media, which is especially relevant in patients with compromised renal function or severe allergies who cannot receive intravenous gadolinium-based contrast media (23). However, it is unclear what maximal b-values should be used to obtain unbiased IVIM measurements, in which the contributions from non-Gaussian diffusion are negligible. Thus, we investigated the applicability of IVIM parameters based on different combinations of five b-values (0, 188, 375, 563 and 750 s/mm2) obtained from DW-MR images during MP-MRI prostate studies. The measurements and simulation produced results with significantly increased f and significantly reduced D in tumors compared to benign tissues, provided that the highest b-value (750 s/mm2) was excluded from analysis.
TL;DR: It is demonstrated that T1 mapping may have potential to detect subclinical myocardial involvement in patients with SLE and showed the greatest concordance with the presence of clinical diagnosis of SLE.
Abstract: Background— Increased systemic inflammation has been linked to myocardial dysfunction and heart failure in patients with systemic lupus erythematosus (SLE). Accurate detection of early myocardial changes may be able to guide preventive intervention. We investigated whether multiparametric imaging by cardiovascular magnetic resonance can detect differences between controls and asymptomatic SLE patients.
Methods and Results— A total of 33 SLE predominantly female patients (mean age, 40±9 years) underwent cardiovascular magnetic resonance for routine assessment of myocardial perfusion, function, and late gadolinium enhancement. T1 mapping was performed in single short-axis slice before and after 15 minutes of gadolinium administration. Twenty-one subjects with a low pretest probability and normal cardiovascular magnetic resonance served as a control group. Both groups had similar left ventricular volumes and mass and normal global systolic function. SLE patients had significantly reduced longitudinal strain (controls versus SLE, −20±2% versus −17±3%; P <0.01) and showed intramyocardial and pericardial late gadolinium enhancement. SLE patients had significantly increased native myocardial T1 (1056±27 versus 1152±46 milliseconds; P <0.001) and extracellular volume fraction (26±5% versus 30±6%; P =0.007) and reduced postcontrast myocardial T1 (454±53 versus 411±62 milliseconds; P =0.01). T1-derived indices were associated with longitudinal strain ( r =0.37–0.47) but not with the presence of late gadolinium enhancement. Native myocardial T1 values showed the greatest concordance with the presence of clinical diagnosis of SLE.
Conclusions— In patients with SLE and free of cardiac symptoms, there is evidence of subclinical perimyocardial impairment. We further demonstrate that T1 mapping may have potential to detect subclinical myocardial involvement in patients with SLE.
TL;DR: Assessing multiparametric magnetic resonance imaging as a diagnostic tool for all prostate cancer,Biopsy Gleason score 7 or greater, and biopsy Gle Mason score 8 or greater separately via ROC analyses demonstrated increasing accuracy of multiparametry magnetic resonance Imaging for higher grade disease.
TL;DR: The semiautomated plaque quantification algorithm identified several parameters predictive for ACS and provided incremental prognostic value over clinical risk profile and conventional CT reading and the application of this tool may improve risk stratification in patients undergoing CCTA.
TL;DR: It is shown that cyclin-dependent kinase (CDK)-mediated, mitosis-specific phosphorylation of SGO1 activates its cohesion-protection function and enables its direct binding to cohesin, and that PP2A-orchestrated, site-selective dephosphorylated of cohes in and its regulators underlies centromeric cohesion protection.
Abstract: Accurate chromosome segregation requires that sister-chromatid cohesion is resolved first at chromosome arms in prophase and then at centromeres in metaphase. In prophase, centromeric cohesion is protected by shugoshin and protein phosphase 2A (SGO1–PP2A). Yu and colleagues show that CDK1-mediated phosphorylation of SGO1 promotes SGO1–PP2A binding to cohesin, and dephosphorylation of the cohesion-promoting component sororin to prevent cohesin removal.
TL;DR: A benchmarking framework for the validation of cardiac motion analysis algorithms is presented and good agreement was found between the different modalities and methodologies, except for radial strain that showed a high variability in cases of lower image quality.
TL;DR: In this paper, a review of methods of inference for single and multiple change-points in time series, when data are of retrospective (off-line) type, is presented.
Abstract: The article reviews methods of inference for single and multiple change-points in time series, when data are of retrospective (off-line) type. The inferential methods reviewed for a single change-point in time series include likelihood, Bayes, Bayes-type and some relevant non-parametric methods. Inference for multiple change-points requires methods that can handle large data sets and can be implemented efficiently for estimating the number of change-points as well as their locations. Our review in this important area focuses on some of the recent advances in this direction. Greater emphasis is placed on multivariate data while reviewing inferential methods for a single change-point in time series. Throughout the article, more attention is paid to estimation of unknown change-point(s) in time series, and this is especially true in the case of multiple change-points. Some specific data sets for which change-point modelling has been carried out in the literature are provided as illustrative examples under both single and multiple change-point scenarios.
TL;DR: It is found that the postgrowth piranha etching is critical for obtaining a good solar cell performance and a high diode rectification factor of 10(7) is obtained at ±1 V.
Abstract: We demonstrate an efficiency enhancement of an InP nanowire (NW) axial p–n junction solar cell by cleaning the NW surface. NW arrays were grown with in situ HCl etching on an InP substrate patterned by nanoimprint lithography, and the NWs surfaces were cleaned after growth by piranha etching. We find that the postgrowth piranha etching is critical for obtaining a good solar cell performance. With this procedure, a high diode rectification factor of 107 is obtained at ±1 V. The resulting NW solar cell exhibits an open-circuit voltage (Voc) of 0.73 V, a short-circuit current density (Jsc) of 21 mA/cm2, and a fill factor (FF) of 0.73 at 1 sun. This yields a power conversion efficiency of up to 11.1% at 1 sun and 10.3% at 12 suns.
Patent•
20 Jun 2013TL;DR: In this paper, a fiber optic shape sensing device is inserted into a lumen and an instrument is guided to the locations of branches indicated on a rendering of the lumen to visualize branches.
Abstract: A method for visualizing branches of a lumen includes inserting (402) a fiber optic shape sensing device into a lumen and determining (404)changes in the lumen based upon strain induced in the fiber optic shape sensing device by flow in the lumen. Locations of branches are indicated (410) on a rendering of the lumen. An instrument is guided (414) to the locations of branches indicated on the rendering.