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Resumen Introducción: En los pacientes con DCPT, la disfunción ventricular es inevitable, y más temprana en VU derechos. La deformación miocárdica por STE y RMC-FT parece promisoria. Objetivo: Analizar la función ventricular mediante STE y RMC-FT en pacientes con DCPT, en comparación con RMC convencional según la morfología del VU y la posible implicación en su diagnóstico temprano. Método: Se recogieron medidas del strain longitudinal y circunferencial por STE y RMC-FT, volúmenes ventriculares y FE por RMC en 64 pacientes con DCPT. Resultados: La morfología ventricular no se relacionó con disfunción por RMC. Los VU derechos tuvieron valores por STE y RMC-FT disminuidos respecto de los VU izquierdos, con FE similares. Existe correlación entre STE y RMC-FT, no equivalentes, con buena factibilidad y reproducibilidad. Conclusiones: La RMC-FT y el STE son técnicas útiles en el diagnóstico temprano y la vigilancia de la función ventricular en VU derechos con FE preservada.
Abstract Introduction: In patients with TCPC, the development of ventricular dysfunction is inevitable and is more precocious in SRVs. Myocardial deformation by STE and CMR-FT is promising. Objective: To analize ventricular function in patients with TCPC using STE and CMR-FT compared with conventional cMRI, depending on SV morphology, to determine their role in early diagnosis of ventricular dysfunction. Method: Sixty-four patients with TCPC were included. Longitudinal and circumferential strain by STE and CMR-FT and ventricular volume and EF were obtained. Results: Dysfunction analyzed by cMRI showed no association with ventricular morphology. SRVs had lower values in STE and CMR-FT compared with SLVs, with similar EF. While not equivalent, correlation was observed between the STE and the CMR-FT values, demonstrating good feasibility and reproducibility. Conclusion: The strain data in CMR-FT and STE could be useful for diagnosis and monitoring of ventricular function and as markers of early SRV dysfunction with preserved EF.
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A novel method to extract the seven parameters of the double-diode model of solar cells using the current-voltage (I-V) characteristics under illumination and in the dark is presented. The algorithm consists of two subroutines which are alternatively run to adjust all the parameters of the cell in an iterative process. Curve fitting of the light I-V characteristics ensures accuracy in the prediction of the maximum power point, whereas simultaneously fitting the dark I-V characteristics results in a set of physically meaningful parameters that provide information about the physical performance of the photovoltaic devices. Experimental I-V curves of in-house solar cells are used to validate the proposed parameter extraction method, which can be furthermore applied to other types of p-n junction-based photovoltaic devices.
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For current microelectronic integrated systems, the design methodology involves different steps that end up in the full system simulation by means of electrical and physical models prior to its manufacture. However, the higher the circuit complexity, the more time is required to complete these simulations, jeopardizing the convergence of the numerical methods and, hence, meaning that the reliability of the results are not guaranteed. This paper shows the use of a high-level tool based on Matlab to simulate the operation of an artificial neural network implemented in a mixed analog-digital CMOS process, intended for sensor calibration purposes. The proposed standard tool enables modification of the neural model architecture to adapt its characteristics to those of the electronic system, resulting in accurate behavioral models that predict the complete microelectronic IC system behavior under different operation conditions before its physical implementation with a simple, time-efficient, and reliable solution.
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This paper presents a novel structure of Resistance- to-Period (R-T) Converter highly robust to supply and temperature variations. Robustness is achieved by using the ratiometric approach so that complex circuits or high accuracy voltage references are not necessary. To prove the proposed architecture of R-T converter, a prototype was implemented in a 0.18 µ m CMOS process with a single supply voltage of 1.8 V and without any stable reference voltage. Experimental results show a maximum ±1.5% output signal variation for ±10% supply voltage variation and in a 3â»95 ° C temperature range.
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This paper presents a new micropower analog lock-in amplifier (LIA) suitable for battery-operated applications thanks to its reduced size and power consumption as well as its operation with single-supply voltage. The proposed LIA was designed in a 0.18 µm CMOS process with a single supply voltage of 1.8 V. Experimental results show a variable DC gain ranging from 24.7 to 42 dB, power consumption of 417 µW and integration area of 0.013 mm2. The LIA performance was demonstrated by measuring carbon monoxide concentrations as low as 1 ppm in dry N2. The experimental results show that the response to CO of the sensing system can be considerably improved by means of the proposed LIA.