The Effect of Vibration on Blood Flow and Pressure in the Major Arteries of Dogs

The response of various systems in the human body to forces transmitted from vehicles and machinery has been the object of much research in recent years, but there have been few direct experimental measurements of cardiovascular function in a dynamic environment. This report describes both in vitro and in vivo approaches to analyzing the cardiovascular effects of vibration. First, a simplified 'mechanical' model of the circulatory system was constructed and exposed to sinusoidal vibration. Next, electromagnetic flow transducers were chronically implanted around the aorta and the pulmonary and carotid arteries of a dog. After recovery the animal was anesthetized, placed in an upright position (spine vertical), and vibraed at 2 to 12 Hz and at 1 to 3G acceleration amplitude in the direction of the gravity vector. Variables measured were blood flow rate, arterial pressure, and force transmitted between animal and vibration exciter. The purpose was to determine the maximum and minimum peak flow rates, pressures, and transmitted force during vibration compared to normal levels. Presented at the Symposium on Biodynamics Models and Their Applications held at Dayton, Ohio, on 26-28 Oct 70. Paper also included in AD-739 501, PC $11.00, MF $0.95.