( ( To ( measure ( blood pressure ) ) ) ( , ( ( ( a device ) ( known ( as ( ( ( a sphygmomanometer ) and ) ( a stethoscope ) ) ) ) ) ( ( are needed ) . ) ) ) )
(ROOT (S (S (VP (TO To) (VP (VB measure) (NP (NN blood) (NN pressure))))) (, ,) (NP (NP (DT a) (NN device)) (VP (VBN known) (PP (IN as) (NP (NP (DT a) (NN sphygmomanometer)) (CC and) (NP (DT a) (NN stethoscope)))))) (VP (VBP are) (VP (VBN needed))) (. .)))
To measure blood pressure, a device known as a sphygmomanometer and a stethoscope are needed .
(ROOT (S (NP (NNP Sphygmomanometer)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN blood) (NN pressure))))))) (. .)))