The Experts below are selected from a list of 78603 Experts worldwide ranked by ideXlab platform
Amir Lerman - One of the best experts on this subject based on the ideXlab platform.
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pulse transmission coefficient a nonhyperemic index for physiologic assessment of procedural success following percutaneous coronary interventions
Catheterization and Cardiovascular Interventions, 2004Co-Authors: David Brosh, Ryan J Lennon, Morton J Kern, Stuart T Higano, David R Holmes, Amir LermanAbstract:Intracoronary Pressure measurements and the determination of fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) predict adverse events. Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a high-frequency filter. The pulse transmission coefficient (PTC) is a nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. It was shown recently that PTC is highly correlated with FFR. This study was designed to examine the change of PTC as compared to FFR following PCI. Pressure Signals were obtained by Pressure guidewire in 27 lesions pre- and post-PCI and were analyzed with an algorithm that identifies the high-frequency component in the Pressure Signal. The PTC was calculated at baseline as the ratio between distal and proximal high-frequency components of the Pressure waveform across the lesion. FFR measurements were assessed with intracoronary adenosine. There was a significant increase in PTC following PCI (0.15 ± 0.17 at baseline vs. 0.84 ± 0.11 post-PCI; P < 0.001). Comparable changes were observed for FFR (0.58 ± 0.12 at baseline vs. 0.91 ± 0.05 post-PCI; P < 0.001). PTC is a nonhyperemic parameter for physiologic assessment of coronary artery stenoses. Similar to FFR, PTC is significantly increased following PCI. Thus, it may serve as an adjunct index for the functional assessment of procedural success following PCI. Catheter Cardiovasc Interv 2004;61:95–102. © 2004 Wiley-Liss, Inc.
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pulse transmission coefficient a novel nonhyperemic parameter for assessing the physiological significance of coronary artery stenoses
Journal of the American College of Cardiology, 2002Co-Authors: David Brosh, Hylton Miller, Ryan J Lennon, Morton J Kern, Marvin J. Slepian, Stuart T Higano, David R Holmes, Amir LermanAbstract:Objectives We sought to test the hypothesis that the pulse transmission coefficient (PTC) can serve as a nonhyperemic physiologic marker for the severity of coronary artery stenosis in humans. Background Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a low-pass filter. The PTC is a novel nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. Thus, it may reflect the severity of the coronary artery stenosis. This study was designed to examine the correlation between PTC and fractional flow reserve (FFR) in patients with coronary artery disease. Methods Pressure Signals were obtained by Pressure guidewire in 56 lesions (49 patients) in the nonhyperemic state and were analyzed with a new algorithm that identifies the high-frequency components in the Pressure Signal. The PTC was calculated as the ratio between the distal and proximal high-frequency components of the Pressure waveform across the lesion. The FFR measurements were assessed with intracoronary adenosine. Results There was a significant correlation between PTC and FFR (r = 0.81, p < 0.001). By using a receiver operating characteristic analysis, we identified a PTC < 0.60 (sensitivity 100%, specificity 98%) to be the optimal cutoff value for predicting an FFR < 0.75. Conclusions Pulse transmission coefficient is a novel nonhyperemic parameter for the physiologic assessment of coronary artery stenoses. It correlates significantly with FFR and may predict an FFR < 0.75 with high accuracy. Pulse transmission coefficient may be useful as an adjunct measurement to FFR, especially in patients with microcirculatory disease and impaired maximal hyperemia.
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pulse transmission coefficient a novel nonhyperemic parameter for assessing the physiological significance of coronary artery stenoses
Journal of the American College of Cardiology, 2002Co-Authors: David Brosh, Hylton Miller, Ryan J Lennon, Morton J Kern, Marvin J. Slepian, Stuart T Higano, David R Holmes, Amir LermanAbstract:Abstract Objectives We sought to test the hypothesis that the pulse transmission coefficient (PTC) can serve as a nonhyperemic physiologic marker for the severity of coronary artery stenosis in humans. Background Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a low-pass filter. The PTC is a novel nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. Thus, it may reflect the severity of the coronary artery stenosis. This study was designed to examine the correlation between PTC and fractional flow reserve (FFR) in patients with coronary artery disease. Methods Pressure Signals were obtained by Pressure guidewire in 56 lesions (49 patients) in the nonhyperemic state and were analyzed with a new algorithm that identifies the high-frequency components in the Pressure Signal. The PTC was calculated as the ratio between the distal and proximal high-frequency components of the Pressure waveform across the lesion. The FFR measurements were assessed with intracoronary adenosine. Results There was a significant correlation between PTC and FFR (r = 0.81, p Conclusions Pulse transmission coefficient is a novel nonhyperemic parameter for the physiologic assessment of coronary artery stenoses. It correlates significantly with FFR and may predict an FFR
David Brosh - One of the best experts on this subject based on the ideXlab platform.
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pulse transmission coefficient a nonhyperemic index for physiologic assessment of procedural success following percutaneous coronary interventions
Catheterization and Cardiovascular Interventions, 2004Co-Authors: David Brosh, Ryan J Lennon, Morton J Kern, Stuart T Higano, David R Holmes, Amir LermanAbstract:Intracoronary Pressure measurements and the determination of fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) predict adverse events. Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a high-frequency filter. The pulse transmission coefficient (PTC) is a nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. It was shown recently that PTC is highly correlated with FFR. This study was designed to examine the change of PTC as compared to FFR following PCI. Pressure Signals were obtained by Pressure guidewire in 27 lesions pre- and post-PCI and were analyzed with an algorithm that identifies the high-frequency component in the Pressure Signal. The PTC was calculated at baseline as the ratio between distal and proximal high-frequency components of the Pressure waveform across the lesion. FFR measurements were assessed with intracoronary adenosine. There was a significant increase in PTC following PCI (0.15 ± 0.17 at baseline vs. 0.84 ± 0.11 post-PCI; P < 0.001). Comparable changes were observed for FFR (0.58 ± 0.12 at baseline vs. 0.91 ± 0.05 post-PCI; P < 0.001). PTC is a nonhyperemic parameter for physiologic assessment of coronary artery stenoses. Similar to FFR, PTC is significantly increased following PCI. Thus, it may serve as an adjunct index for the functional assessment of procedural success following PCI. Catheter Cardiovasc Interv 2004;61:95–102. © 2004 Wiley-Liss, Inc.
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pulse transmission coefficient a novel nonhyperemic parameter for assessing the physiological significance of coronary artery stenoses
Journal of the American College of Cardiology, 2002Co-Authors: David Brosh, Hylton Miller, Ryan J Lennon, Morton J Kern, Marvin J. Slepian, Stuart T Higano, David R Holmes, Amir LermanAbstract:Objectives We sought to test the hypothesis that the pulse transmission coefficient (PTC) can serve as a nonhyperemic physiologic marker for the severity of coronary artery stenosis in humans. Background Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a low-pass filter. The PTC is a novel nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. Thus, it may reflect the severity of the coronary artery stenosis. This study was designed to examine the correlation between PTC and fractional flow reserve (FFR) in patients with coronary artery disease. Methods Pressure Signals were obtained by Pressure guidewire in 56 lesions (49 patients) in the nonhyperemic state and were analyzed with a new algorithm that identifies the high-frequency components in the Pressure Signal. The PTC was calculated as the ratio between the distal and proximal high-frequency components of the Pressure waveform across the lesion. The FFR measurements were assessed with intracoronary adenosine. Results There was a significant correlation between PTC and FFR (r = 0.81, p < 0.001). By using a receiver operating characteristic analysis, we identified a PTC < 0.60 (sensitivity 100%, specificity 98%) to be the optimal cutoff value for predicting an FFR < 0.75. Conclusions Pulse transmission coefficient is a novel nonhyperemic parameter for the physiologic assessment of coronary artery stenoses. It correlates significantly with FFR and may predict an FFR < 0.75 with high accuracy. Pulse transmission coefficient may be useful as an adjunct measurement to FFR, especially in patients with microcirculatory disease and impaired maximal hyperemia.
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pulse transmission coefficient a novel nonhyperemic parameter for assessing the physiological significance of coronary artery stenoses
Journal of the American College of Cardiology, 2002Co-Authors: David Brosh, Hylton Miller, Ryan J Lennon, Morton J Kern, Marvin J. Slepian, Stuart T Higano, David R Holmes, Amir LermanAbstract:Abstract Objectives We sought to test the hypothesis that the pulse transmission coefficient (PTC) can serve as a nonhyperemic physiologic marker for the severity of coronary artery stenosis in humans. Background Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a low-pass filter. The PTC is a novel nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. Thus, it may reflect the severity of the coronary artery stenosis. This study was designed to examine the correlation between PTC and fractional flow reserve (FFR) in patients with coronary artery disease. Methods Pressure Signals were obtained by Pressure guidewire in 56 lesions (49 patients) in the nonhyperemic state and were analyzed with a new algorithm that identifies the high-frequency components in the Pressure Signal. The PTC was calculated as the ratio between the distal and proximal high-frequency components of the Pressure waveform across the lesion. The FFR measurements were assessed with intracoronary adenosine. Results There was a significant correlation between PTC and FFR (r = 0.81, p Conclusions Pulse transmission coefficient is a novel nonhyperemic parameter for the physiologic assessment of coronary artery stenoses. It correlates significantly with FFR and may predict an FFR
Chengkai Huang - One of the best experts on this subject based on the ideXlab platform.
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an engine fault diagnosis system using intake manifold Pressure Signal and wigner ville distribution technique
Expert Systems With Applications, 2011Co-Authors: Jianda Wu, Chengkai HuangAbstract:This paper proposed an engine fault diagnosis system based on intake manifold Pressure Signal and artificial neural network with the Wigner-Ville distribution technique. Traditionally, the engine diagnostic method depends on the experience of the technician, but some faults might be inaccurately judged by the technician's experience when the engine is operating. In the present study, an engine platform diagnosis system using intake manifold Pressure was developed. The algorithm of the proposed system consisted of Wigner-Ville distribution (WVD) for feature extraction and the neural network technique for fault classification. In previous work, the Wigner-Ville distribution was often used to analyze the non-stationary Signal, because it provides a simple and clear energy spectrum diagram both in the time and frequency domains. This instantaneous energy diagram presented the magnitude of each engine fault under various operating conditions. The Wigner-Ville distribution extracts these features as database input to a neural network and the neural network is used to develop the training and testing modules. To prove the efficiency of the neural network, both the radial basis function neural network and generalized regression neural network are used and compared. The experimental results demonstrated the proposed system is effective and the performance is satisfactory.
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fault diagnosis for internal combustion engines using intake manifold Pressure and artificial neural network
Expert Systems With Applications, 2010Co-Authors: Chengkai Huang, Yowei Chang, Yaojung ShiaoAbstract:This paper describes an internal combustion engine fault diagnosis system using the manifold Pressure of the intake system. The manifold Pressure of the engine intake system always demonstrates the engine condition and affects the volumetric efficiency, fuel consumption and performance of internal combustion engines. Manifold Pressure is well known to be detrimental to engine system stability and performance and it must be considered during regular maintenance. Conventional engine diagnostic technology using manifold Pressure in intake system already exists through analyzing the differences between Signals and depends on the experience of the technician. Obviously, the conventional detection is not a precise approach for manifold Pressure detection when the engine in operation condition. In the present study, a system consisted of manifold Pressure Signal feature extraction using discrete wavelet transform (DWT) and fault recognition using the neural network technique is proposed. To verify the effect of the proposed system for identification, both the radial basis function network (RBFN) and generalized regression neural network (GRNN) are used and compared in this study. The experimental results indicated the proposed system using manifold Pressure Signal as data input is effective for engine fault diagnosis in the experimental engine platform.
Franz Konstantin Fuss - One of the best experts on this subject based on the ideXlab platform.
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muscle performance investigated with a novel smart compression garment based on Pressure sensor force myography and its validation against emg
Frontiers in Physiology, 2018Co-Authors: Aaron Belbasis, Franz Konstantin FussAbstract:Muscle activity and fatigue performance parameters were obtained and compared between both a smart compression garment and the gold-standard, a surface electromyography (EMG) system during high-speed cycling in seven participants. The smart compression garment, based on force myography (FMG), comprised of integrated Pressure sensors that were sandwiched between skin and garment, located on five thigh muscles. The muscle activity was assessed by means of crank cycle diagrams (polar plots) that displayed the muscle activity relative to the crank cycle. The fatigue was assessed by means of the median frequency of the power spectrum of the EMG Signal; the fractal dimension (FD) of the EMG Signal; and the FD of the Pressure Signal. The smart compression garment returned performance parameters (muscle activity and fatigue) comparable to the surface EMG. The major differences were that the EMG measured the electrical activity, whereas the Pressure sensor measured the mechanical activity. As such, there was a phase shift between electrical and mechanical Signals, with the electrical Signals preceding the mechanical counterparts in most cases. This is specifically pronounced in high-speed cycling. The fatigue trend over the duration of the cycling exercise was clearly reflected in the fatigue parameters (FDs and median frequency) obtained from Pressure and EMG Signals. The fatigue parameter of the Pressure Signal (FD) showed a higher time dependency (R2 = 0.84) compared to the EMG Signal. This reflects that the Pressure Signal puts more emphasis on the fatigue as a function of time rather than on the origin of fatigue (e.g., peripheral or central fatigue). In light of the high-speed activity results, caution should be exerted when using data obtained from EMG for biomechanical models. In contrast to EMG data, activity data obtained from FMG are considered more appropriate and accurate as an input for biomechanical modeling as they truly reflect the mechanical muscle activity. In summary, the smart compression garment based on FMG is a valid alternative to EMG-garments and provides more accurate results at high-speed activity (avoiding the electro-mechanical delay), as well as clearly measures the progress of muscle fatigue over time.
Morton J Kern - One of the best experts on this subject based on the ideXlab platform.
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pulse transmission coefficient a nonhyperemic index for physiologic assessment of procedural success following percutaneous coronary interventions
Catheterization and Cardiovascular Interventions, 2004Co-Authors: David Brosh, Ryan J Lennon, Morton J Kern, Stuart T Higano, David R Holmes, Amir LermanAbstract:Intracoronary Pressure measurements and the determination of fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) predict adverse events. Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a high-frequency filter. The pulse transmission coefficient (PTC) is a nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. It was shown recently that PTC is highly correlated with FFR. This study was designed to examine the change of PTC as compared to FFR following PCI. Pressure Signals were obtained by Pressure guidewire in 27 lesions pre- and post-PCI and were analyzed with an algorithm that identifies the high-frequency component in the Pressure Signal. The PTC was calculated at baseline as the ratio between distal and proximal high-frequency components of the Pressure waveform across the lesion. FFR measurements were assessed with intracoronary adenosine. There was a significant increase in PTC following PCI (0.15 ± 0.17 at baseline vs. 0.84 ± 0.11 post-PCI; P < 0.001). Comparable changes were observed for FFR (0.58 ± 0.12 at baseline vs. 0.91 ± 0.05 post-PCI; P < 0.001). PTC is a nonhyperemic parameter for physiologic assessment of coronary artery stenoses. Similar to FFR, PTC is significantly increased following PCI. Thus, it may serve as an adjunct index for the functional assessment of procedural success following PCI. Catheter Cardiovasc Interv 2004;61:95–102. © 2004 Wiley-Liss, Inc.
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pulse transmission coefficient a novel nonhyperemic parameter for assessing the physiological significance of coronary artery stenoses
Journal of the American College of Cardiology, 2002Co-Authors: David Brosh, Hylton Miller, Ryan J Lennon, Morton J Kern, Marvin J. Slepian, Stuart T Higano, David R Holmes, Amir LermanAbstract:Objectives We sought to test the hypothesis that the pulse transmission coefficient (PTC) can serve as a nonhyperemic physiologic marker for the severity of coronary artery stenosis in humans. Background Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a low-pass filter. The PTC is a novel nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. Thus, it may reflect the severity of the coronary artery stenosis. This study was designed to examine the correlation between PTC and fractional flow reserve (FFR) in patients with coronary artery disease. Methods Pressure Signals were obtained by Pressure guidewire in 56 lesions (49 patients) in the nonhyperemic state and were analyzed with a new algorithm that identifies the high-frequency components in the Pressure Signal. The PTC was calculated as the ratio between the distal and proximal high-frequency components of the Pressure waveform across the lesion. The FFR measurements were assessed with intracoronary adenosine. Results There was a significant correlation between PTC and FFR (r = 0.81, p < 0.001). By using a receiver operating characteristic analysis, we identified a PTC < 0.60 (sensitivity 100%, specificity 98%) to be the optimal cutoff value for predicting an FFR < 0.75. Conclusions Pulse transmission coefficient is a novel nonhyperemic parameter for the physiologic assessment of coronary artery stenoses. It correlates significantly with FFR and may predict an FFR < 0.75 with high accuracy. Pulse transmission coefficient may be useful as an adjunct measurement to FFR, especially in patients with microcirculatory disease and impaired maximal hyperemia.
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pulse transmission coefficient a novel nonhyperemic parameter for assessing the physiological significance of coronary artery stenoses
Journal of the American College of Cardiology, 2002Co-Authors: David Brosh, Hylton Miller, Ryan J Lennon, Morton J Kern, Marvin J. Slepian, Stuart T Higano, David R Holmes, Amir LermanAbstract:Abstract Objectives We sought to test the hypothesis that the pulse transmission coefficient (PTC) can serve as a nonhyperemic physiologic marker for the severity of coronary artery stenosis in humans. Background Coronary lesions may impair the transmission of Pressure waves across a stenosis, potentially acting as a low-pass filter. The PTC is a novel nonhyperemic parameter that calculates the transmission of high-frequency components of the Pressure Signal through a stenosis. Thus, it may reflect the severity of the coronary artery stenosis. This study was designed to examine the correlation between PTC and fractional flow reserve (FFR) in patients with coronary artery disease. Methods Pressure Signals were obtained by Pressure guidewire in 56 lesions (49 patients) in the nonhyperemic state and were analyzed with a new algorithm that identifies the high-frequency components in the Pressure Signal. The PTC was calculated as the ratio between the distal and proximal high-frequency components of the Pressure waveform across the lesion. The FFR measurements were assessed with intracoronary adenosine. Results There was a significant correlation between PTC and FFR (r = 0.81, p Conclusions Pulse transmission coefficient is a novel nonhyperemic parameter for the physiologic assessment of coronary artery stenoses. It correlates significantly with FFR and may predict an FFR
