Noninvasive techniques have been devised to estimate cardiac output (Q) during exercise to obviate vascular cannulation. However, although these techniques are noninvasive, they are commonly not nonintrusive to subjects' spontaneous ventilation and gas-exchange responses. We hypothesized that the exercise stroke volume (SV) and, hence, Q might be accurately estimated simply from the response pa...

In acute circulatory failure, passive leg raising (PLR) is a test that predicts whether cardiac output will increase with volume expansion [1]. By transferring a volume of around 300 mL of venous blood [2] from the lower body toward the right heart, PLR mimics a fluid challenge. However, no fluid is infused and the hemodynamic effects are rapidly reversible [1,3], thereby avoiding the risks of ...

OBJECTIVE To assess the fragmentation (ablation) efficiency of laser lithotripsy along a wide range of pulse energies, frequencies, power settings and different laser fibres, in particular to compare high- with low-frequency lithotripsy using a dynamic and innovative testing procedure free from any human interaction bias. MATERIALS AND METHODS An automated laser fragmentation testing system w...

T HE INCREASE of pulse wave velocity with age is well established1-3 and reflects a loss of the elastic properties of the arterial wall.4 The age trends of pulse wave velocity vary for different arteries.2 8 In view of early localization of atherosclerotic changes in the abdominal aorta, we have compared age trends of the aortic pulse wave velocity, measured by impedance plethysmography in norm...

Oxygen treatment based on intermittent-flow devices with pulse delivery modes available from portable oxygen concentrators (POCs) depends on the characteristics of the delivered pulse such as volume, pulse width (the time of the pulse to be delivered), and pulse delay (the time for the pulse to be initiated from the start of inhalation) as well as a patient's breathing characteristics, disease ...

T HE INCREASE of pulse wave velocity with age is well established1-3 and reflects a loss of the elastic properties of the arterial wall.4 The age trends of pulse wave velocity vary for different arteries.2 8 In view of early localization of atherosclerotic changes in the abdominal aorta, we have compared age trends of the aortic pulse wave velocity, measured by impedance plethysmography in norm...

OBJECTIVE Pregnancy induces a smaller rise in plasma volume in formerly preeclamptic women with a pre-existent subnormal plasma volume than in their counterparts with a normal plasma volume. These women also have a three times higher recurrence rate of pregnancy-induced hypertensive disorders. In this study we tested the hypothesis that a subnormal plasma volume in these women is related to a l...

PURPOSE The purpose of this study was to characterize the pressure-volume relation in the living human eye, measure the ocular pulse amplitude (OPA), and calculate the corresponding pulsatile ocular blood flow (POBF) in a range of clinically relevant IOP levels. METHODS Fifty patients with cataract (50 eyes) were enrolled in the study. After cannulation of the anterior chamber, a computer-con...