We numerically simulate the performance of the ultrasimple frequency-resolved-optical-gating (FROG) technique, GRENOUILLE, for measuring ultrashort laser pulses. While simple in practice, GRENOUILLE has many theoretical subtleties because it involves the second-harmonic generation of relatively tightly focused and broadband pulses. In addition, these processes occur in a thick crystal, in which...

A gas monitor detector was implemented and characterized at the Soft X-ray Research (SXR) instrument to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. The detector is placed after the monochromator and addresses the need to provide reliable absolute pulse energy as well as pulse-resolved measurements for the various exp...

A new frequency-resolved bunch-length measuring system has been developed at the Stanford SUNSHINE facility to characterize subpicosecond electron pulses. Using a far-infrared Michelson interferometer, this method measures the spectrum of coherent transition radiation emitted from electron bunches through optical autocorrelation. The electron bunch length is obtained from the measurement with a...

O R IG IN A L PA ER Abstract Multi-shot pulse-shape measurements of trains of ultrashort pulses with unstable pulse shapes are studied. Measurement techniques considered include spectral-phase interferometry for direct electric-field reconstruction (SPIDER), second harmonic generation frequency-resolved optical gating (FROG), polarization gate FROG, and cross-correlation FROG. An analytical cal...

The key of ankle-brachial index (ABI) measurement is accurately measurement of upper and lower extremities systolic pressure. When the blood flow is blocked, blood flow will resume a normal beat and the corresponding cuff pressure of the first trough starting point is the systolic pressure. First it detects the pulse signal main frequency by spectral analysis of the pulse signal which based on ...

Pulse pressure velocity measurements (PPV) may be a source of useful information on artery state. A 2007 guideline of the European Society of Hypertension recommends assessing arterial stiffness in patients with arterial hypertension, by measuring the PPV. Mechanical changes in the cardiovascular tree involved in the blood ejection have been measured at the thorax level and on the wrist using i...

The great incidence of cardiovascular (CV) diseases in the world spurs the search for new solutions to enable an early detection of pathological processes and provides more precise diagnosis based in multi-parameters assessment. The pulse wave velocity (PWV) is considered one of the most important clinical parameters for evaluate the CV risk, vascular adaptation, and therapeutic efficacy. Sever...

Determination of Travel Distance for Noninvasive Measurement of Pulse Wave Velocity: Case Closed? To the Editor: Carotid-femoral pulse wave velocity (cfPWV) is currently considered the gold-standard measurement for arterial stiffness.1 In clinical routine, noninvasive assessment is the only feasible method, whereas, for research purposes, catheter-based invasive determination, as well as MRI, m...

Pulse radar has been used widely for distance measurement since the very beginnings of radar technology. The basic form of pulse radar is a pure time of flight measurement. Short pulses, typically of millisecond or nanosecond duration, are transmitted and the transit time to and from the target is measured. The pulses of a pulse radar are not discrete monopulses with a single peak of electromag...

Pulse wave analysis permits non-invasive assessment of arterial elasticity indices. The contour varies in different parts of the circulation. It depends on physiological or pathophysiological conditions of the organism. The pathological events like arteriosclerosis or diabetes have a primary effect to the artery elasticity. Hypertension or some heart diseases also influence the pulse wave veloc...