Mechanical vibration in neonatal transport.

Mechanical vibration encountered in land transports was assessed objectively through measurement of vertical acceleration experienced by neonates in transit. Vibration was most predominant in the hazardous low frequency range of 3 to 18 Hz. The peak acceleration amplitudes (intermittent thrusts) ranged from 5 to 13 m/sq sec. The root mean square acceleration (averaged vibration) ranged from to 6 m/sq sec. These vibration levels are high when compared with adult vibration tolerance limits, and may jeopardize the safety of the transported infants, particularly in long-distance transports. Further research is needed to understand the possible effects of mechanical vibration in neonates and to define safe vibration thresholds in all modes of transport. Careful-evaluation of vibratory stress and its attenuation in newer designs of transport equipment may be desirable to enhance the safety of the transported infants.