WHITNEY,1 in 1953, introduced the mercury-in-rubber strain gauge in the study of the peripheral circulation; this instrument was later modified by Celander and Thunell2 in 1961 for measurements of blood pressure and peripheral circulation in newly born infants. The purpose of this report is to give our results with the use of a similar mercury-in-silicone-rubber strain gauge to determine blood pressure in premature and full term infants for whom there is currently rather fragmentary information. Studies of the peripheral circulation were also made and have been reported in another communication.3
Material and Methods
The present strain gauge is a silicone rubber tube, id 0.015" × od 0.045" filled with mercury, which is attached circumferentially to the limb. The ends of the tube are closed by copper plugs which are in electrical continuity with the mercury. A Wheatstone bridge, the characteristics of which are given in Fig 1,
LEVISON H, KIDD BSL, GEMMELL PA, SWYER PR. Blood Pressure in Normal Full-Term and Premature Infants. Am J Dis Child. 1966;111(4):374–379. doi:10.1001/archpedi.1966.02090070072009
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