The purpose of this study has the determination of a transfer function to describe response of a dog's heart to longitudinal whole body sinusoidal vibration. Miniature accelerometers were surgically implanted on four dogs. Electrical-aechanical network analogies Here used to determine velocity transmissibllity response in the vibration range below 13 cycles per second (cps) at double displacements up to 1/4 inch. Response indicated a tin mass coupled system of the formnT(S) " [1 t"* + *sz] [1 +cs + ds*]nUndamped natural frequency of the heart was .5.16 cps; damping ratio was 0.5. Resting heart acceleration could be added to typical *dead heart" response data to predict output acceleration nave forms. The second-mass, with an undamped natural frequency of 7.8 cps, exhibited a damping ratio of 0.1.
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