Daiquan Chen

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The objective of the present work was to test and validate a noninvasive method based on spectral analysis of the second heart sound (S2) to estimate the pulmonary artery (PA) systolic pressure in 89 patients with a bioprosthetic heart valve. The technique was compared with continuous-wave Doppler estimation of PA systolic pressure in these patients. The(More)
[1] We investigate experimentally the functional relationship between capillary pressure, Pc, wetting phase saturation, Sw, and interfacial area per volume between the wetting and nonwetting phases, awn, for drainage and imbibition processes in micromodels of twodimensional pore structures. Within the experimental and analysis error (around 10–15%), the(More)
Aortic valve resistance has been proposed to represent the severity of aortic stenosis because some studies observed that it was less affected by change in flow than the valve-effective orifice area, but this issue remains controversial. The objective of this study was to systematically analyze the theoretical and practical determinants of these parameters(More)
We wished to determine whether evoked force output from a human muscle could be inferred from the amplitude and the frequency of evoked muscular sounds. Sounds from adductor pollicis were recorded with a microphone and compared to evoked force changes produced by varying the intensity of nerve stimulation or of voluntary effort as well as by fatigue and(More)
The current processing performed by commercial instruments to obtain the time-frequency representation (TFR) of pulsed-wave Doppler signals may not be adequate to characterize turbulent flow motions. The assessment of the intensity of turbulence is of high clinical importance and measuring high-frequency (small-scale) flow motions, using Doppler ultrasound(More)
PURPOSE To retrospectively compute dose distributions for lung cancer patients treated with SABR, and to correlate dose distributions with outcome using a tumor control probability (TCP) model. METHODS Treatment plans for 133 NSCLC patients treated using 12 Gy/fxn × 4 (BED=106 Gy), and planned using a pencil-beam (1D-equivalent-path-length, EPL-1D)(More)
Experiments were performed on transparent two-dimensional micro-fluidic porous systems to investigate the relationships among capillary pressure and the interfacial areas per volume among two fluid phases and one solid phase. Capillary pressures were calculated from the observed interfacial curvature of the wetting – non-wetting interface, and these(More)
The purpose of this study is to evaluate the overall accuracy of intensity-modulated radiation therapy (IMRT) and RapidArc delivery using both flattening filter (FF) and flattening filter-free (FFF) modalities based on test cases developed by AAPM Task Group 119. Institutional confidence limits (CLs) were established as the baseline for patient specific(More)
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