Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Engineering
Elevation Of Ventricular Defibrillation Threshold In Dogs By Antiarrhythmic Drugs, Charles F. Babbs, Gkw Yim, S J. Whistler, W A. Tacker, L A. Geddes
Elevation Of Ventricular Defibrillation Threshold In Dogs By Antiarrhythmic Drugs, Charles F. Babbs, Gkw Yim, S J. Whistler, W A. Tacker, L A. Geddes
Weldon School of Biomedical Engineering Faculty Publications
Effects of antiarrhythmic drugs upon the threshold delivered energy (TDE) and threshold peak current (TPC) for electrical ventricular defibrillation by damped sinusoidal shocks were investigated in 25 pentobarbital-anesthetized dogs. TDE and TPC were increased by the three antiarrhythmic drugs tested. Bolus injections produced a transient rise, and continuous infusions produced a steady rise in defibrillation threshold. The maximal percent elevations in mean defibrillation threshold during the 60 minutes after intravenous drug treatment in groups of n = 5 dogs were: Treatment % increase in TDE % increase in TPC Lidocaine bolus (3 mg/kg) 48 26 Lidocaine (0.5 mg/Kg/min) 99 45 …
Measurements Of Young's Modulus Of Elasticity Of The Canine Aorta With Ultrasound, D J. Hughes, Charles F. Babbs, L A. Geddes, J D. Bourland
Measurements Of Young's Modulus Of Elasticity Of The Canine Aorta With Ultrasound, D J. Hughes, Charles F. Babbs, L A. Geddes, J D. Bourland
Weldon School of Biomedical Engineering Faculty Publications
We have developed an ultrasonic technique for determining the dynamic Young's modulus of elasticity (E) of the canine aorta in vivo. Young's modulus was measured in the descending thoracic aorta (DTA) and the abdominal aorta (AA) of 12 dogs over a range of mean blood pressures from 40-200 mmHg. The vessels were excised and dynamic moduli were determined in vitro postmortem from pressure-volume curves. The data so obtained were compared to the in vivo values. In vivo and in vitro moduli increased exponentially with mean distending pressure (P). The equation of best fit for these data was of the form …
Attenuation And Speed Of 10 Mhz Ultrasound In Canine Blood Of Various Packed Cell Volumes At 37c, D J. Hughes, L A. Geddes, Charles F. Babbs, J D. Bourland, V L. Newhouse
Attenuation And Speed Of 10 Mhz Ultrasound In Canine Blood Of Various Packed Cell Volumes At 37c, D J. Hughes, L A. Geddes, Charles F. Babbs, J D. Bourland, V L. Newhouse
Weldon School of Biomedical Engineering Faculty Publications
The attenuation coefficient and the speed of 10 MHz ultrasound were determined in canine blood at 37 oC by a differential path length technique. Blood specimens with packed cell volumes (PCV) ranging from 0 to 53% were prepared by separating the cells from the plasma and mixing the two components. The mean attenuation coefficient increased linearly with packed cell volume, the least squares regression function being (dB/cm) = 0.992 +0.039 PCV with a standard error of the estimate = 0.255. The speed of 10 MHz ultrasound, c, in millimetres per second, increased with packed cell volume, the regression function …