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OBJECTIVE To determine whether the mechanisms of reflex sympathetic dystrophy, a neuropathic pain syndrome characterized by skin blood flow abnormalities associated with sympathetic vasoconstrictor and antidromic vasodilator mechanisms, are solely of peripheral origin or have an additional spinal component and act exclusively through neural or also involve(More)
This article introduces a mean frequency estimator based on a radio frequency (RF) domain complex cross-correlation model (C3M). The C3M estimator differs from the real cross-correlation model (CCM) estimator in two respects; it is an unbiased estimator of blood flow velocity and/or tissue motion independent of the bandwidth of the RF ultrasound signals,(More)
Reflex sympathetic dystrophy (RSD) is a pain syndrome that is characterised by autonomic, motor and sensory disturbances. The syndrome has often been associated with sympathetic dysfunction. Therefore, we investigated whether there are disturbances in the sympathetic function of skin microcirculation in the various clinical stages of RSD. Laser Doppler(More)
Based upon theory, wall shear stress (WSS), an important determinant of endothelial function and gene expression, has been assumed to be constant along the arterial tree and the same in a particular artery across species. In vivo measurements of WSS, however, have shown that these assumptions are far from valid. In this survey we will discuss the assessment(More)
Correlation interpolation is introduced as a method to determine the displacement of moving biological tissue on the basis of a sequence of ultrasonic echo signals. The echo signal is sampled along the echo depth with approximately 4 samples per average high frequency period. Sampling in time occurs with the pulse repetition frequency. The necessary(More)
Long-chain fatty acids are the most important substrates for the heart. In addition, they have been shown to affect signalling pathways and gene expression. To explore the effects of long-chain fatty acids on cardiac gene expression, neonatal rat ventricular myocytes were cultured for 48 h with either glucose (10 mm), fatty acids (palmitic and oleic acid,(More)
Electrical excitation of nociceptive afferents in an extremity has been demonstrated to increase skin blood flow in the contralateral extremity. Hence, one would expect that loose sciatic nerve ligation, which induces an experimental painful peripheral neuropathy, may also provoke a vasodilator response in the contralateral hindpaw. On the non-ligated side,(More)
Ultrasound systems are widely used to visualize in real-time internal structures and blood flow velocity distributions. The latter are estimated from the received ultrasound radio frequency (RF) signals using a mean frequency estimator, capable of estimating the temporal and spatial mean frequency within a given depth and time window (estimation window).(More)
In the past decades, non-invasive vascular ultrasound has substantially improved our insights into artery wall dynamics under normal circumstances and in disease. Although we have learned a lot, the methods in use are subject to improvement. In this review, we discuss the most important achievements in non-invasive assessment of dynamic artery wall(More)
A newly developed correlation interpolation method to measure the regional velocity of moving tissue is evaluated in an experimental setup. Pulsed ultrasound echo signals (center frequency 3.5 MHz) are received from a rotating Agar disk containing scattering particles. When averaging over a depth range of 2.2 mm at a pulse repetition frequency (PRF) of 930(More)