Koldo Redondo

Universidad del País Vasco / Euskal Herriko Unibertsitatea | UPV/EHU · Department of Communications Engineering

Aim Propose new metrics of impulsiveness of manual chest compressions (CCs) that account for shape and duration, separate the characteristics of the compressive part of the CC cycle from those of the recoil part, and are uncorrelated to CC depth and rate. Methods We conducted a retrospective analysis of adult out-of-hospital cardiac arrest monitor...

Introduction: Ventilation is essential for the elimination of carbon dioxide (CO 2 ) from the body during CPR. However, variation in ventilation rate (VR) is an acknowledged confounder for the interpretation of EtCO 2 . VRs that are not according to guidelines alter measured EtCO 2 levels and make the decision of termination of resuscitation (TOR)...

Introduction: Viscoelastic models are widely accepted in modern literature to explain the non-linear relationship between the force applied by the rescuer and the chest displacement that occurs during chest compressions (CCs). Various studies have shown that applying CCs for prolonged periods of time changes chest properties, but proposed models ha...

Introduction: Current resuscitation guidelines recommend depth, rate and complete recoil of chest compressions (CCs) to be monitored as part of CPR quality metrics. The literature also suggests CC impulsiveness as an additional measure of CPR quality. The impulsiveness of CCs has mainly been examined through reduced compression duration, but this f...

Background: There is growing interest in the quality of manual ventilation during cardiopulmonary resuscitation (CPR), but accurate assessment of ventilation parameters remains a challenge. Waveform capnography is currently the reference for monitoring ventilation rate in intubated patients, but fails to provide information on tidal volumes and ins...

IEC 61400-21-1 describes the procedure for measuring the flicker produced by a wind turbine. This is a complex procedure, as it involves the processing of voltage and current time series recorded in a grid connected wind turbine for its entire operating range. The standard assumes that the flicker produced by a wind turbine is related to wind varia...

Aim Characterise how changes in chest compression depth and rate affect variations in end-tidal CO2 (ETCO2) during manual cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA). Methods Retrospective analysis of adult OHCA monitor-defibrillator recordings having concurrent capnogram, compression depth, transthoracic impedance...

Aim: The relationship between force and depth during manual chest compressions depends on the patient and on the dynamics with which the rescuer applies the force. Force-depth models with many fitting parameters have been proposed making physical interpretation complicated. The aim of this work was to design a simpler force-depth model, accommodati...

Rapid Voltage Changes (RVC) produce sudden illuminance changes that can generate flicker. The IEC 61000-4-30 standard defines the procedure for the measurement of RVCs, but it does not include a metric to assess the effect of RVCs on flicker perception. The IEC 61000-4-15 standard establishes the specification of a flickermeter, which assesses the...

Integration of wind energy into the grid faces a great challenge regarding power quality. The International Electrotechnical Commission (IEC) 61400-21 standard defines the electrical characteristics that need to be assessed in a Wind Turbine (WT), as well as the procedure to measure the disturbances produced by the WT. One of the parameters to be a...

Integration of wind energy into the grid faces a great challenge regarding power quality. The International Electrotechnical Commission (IEC)~61400-21 standard defines the electrical characteristics that need to be assessed in a Wind Turbine (WT), as well as the procedure to measure the disturbances produced by the WT. One of the parameters to be a...

The purpose of the present paper is to evaluate the sensitivity of modern lighting technologies to different types of RVCs. In order to do that, 27 modern lamps—mainly LED—have been subjected to real RVCs and their response has been assessed. The detection of RVCs on the grid has been performed according to the IEC 61000-4-30 detection method, whil...

Efficient lighting technologies are not necessarily less sensitive to voltage fluctuations than the incandescent lamp, and therefore a procedure for controlling the immunity of lamps to voltage fluctuations was defined in the IEC 61547 standard. This procedure checks that a lamp is not more sensitive than the incandescent lamp to voltage fluctuatio...

This paper presents a set of verification tests to assist the accurate implementation of flicker measurement in wind turbines. The flicker measurement procedure is defined in the IEC 61400-21 standard, which includes the estimation of a fictitious grid in order to measure voltage fluctuations generated exclusively by the wind turbine. The large mar...

In recent years, several countries have adopted measures aimed at improving the efficiency of energy usage and reducing energy costs. One initiative has been to encourage the use of efficient lighting technologies by replacing inefficient lamps such as the incandescent lamp with more efficient lamps. However, this change can have consequences in te...

The IEC 61000-4-15 standard establishes the functional and design specifications of a flickermeter in order to objectively assess the disturbing light flicker. Some studies reported the unpredictable behavior of the IEC flickermeter when dealing with irregular voltage fluctuations. This deficiency explained the absence of the expected users’ compla...

This paper analyzes the effect of digital differentiation on the measurement of flicker emission from grid-connected wind turbines (WTs). The flicker measurement procedure is defined in the IEC 61400-21 standard, which includes the estimation of a fictitious grid for the measurement of voltage fluctuations exclusively generated by a WT. The study f...

The replacement of incandescent lamps with more energy-efficient lighting technologies has a direct influence on the way flicker is measured. The International Electrotechnical Commission (IEC) established in the 61000-4-15 standard the functional specifications of a flickermeter, taking a standard incandescent lamp’s response to voltage fluctuatio...

The IEC 61000-4-15 standard defines a flickermeter that is universally accepted as the meter used for the objective measurement of a disturbing light flicker. The accurate results provided by the IEC flickermeter under uniform fluctuations stand in contrast with its unpredictable behavior under real conditions when voltage fluctuations are not unif...

Rapid voltage changes are a type of power quality disturbance that has not received sufficient attention in the international power quality standards. IEC 61000-4-30, Ed. 3, will introduce a precise method for their detection and analysis. This paper reviews the definitions and the international regulations on RVCs reports some of the results obtai...

Quantification of the flicker generated by wind turbines is a rather complex process requiring high-precision measurements. Based on the measurements of voltage and current time-series, the procedure uses an inductive circuit model to make the final measurements site-independent. This paper presents a study on the inaccuracy introduced by the numer...

This paper presents a comparative study of the method used for measuring the flicker emission from wind turbines as currently defined in standard IEC 61400-21 and the new proposal included in the draft version of the revised standard. The new procedure applies a different arrangement scheme to the flicker measurements, and simplifies the statistica...

Abstract We present an experimental study of the behavior of modern lighting technologies under supply voltage fluctuations. Some studies have reported that flicker severity measurements could exceed the compatibility levels without leading to flicker complaints when modern lighting is in use. Such conclusions have resulted in two main proposals re...

This work studies the influence of the signal processing method on the flicker measurement of grid connected wind turbine in continuous operation according to the procedure detailed in the IEC 61400-21 standard. Two different methods for solving the fictitious grid are analyzed: Zero Crossing Detection and Short Time Fourier Transform. The deviatio...

The standard IEC 61000-4-15 establishes the design specifications to measure the annoyance produced by flicker. This instrument is based on the working principles and the response to input voltage variations of an incandescent lamp, which was taken as the reference lamp for the design. However, nowadays new lighting technologies are being adopted w...

This paper studies the influence that the power oscillations due to the tower shadow effect and the wind shear have on the flicker emission of fixed-speed wind turbines. For three-bladed wind turbines, the frequency of this characteristic fluctuation of power is 3 times the blade rotational frequency, and it is known as 3P oscillation. This work ai...

In the last years, modern lighting technologies are being adopted worldwide. However, in terms of flicker, the incandescent lamp was the one used as the reference lamp in the design of the standards. Due to their different working principles, the new lamps may have quite a different response to input voltage variations than the response of the inca...

This paper presents an analysis of the influence of the phase relationship between the fundamental frequency and the rectangular voltage fluctuation on flicker measurements made by the International Electrotechnical Commission (IEC) flickermeter. We analytically studied the origin of the deviations for a set of significant fluctuation frequencies....