( ( With apneas ) ( , ( ( the ( sleeping person ) ) ( repeatedly ( ( stops ( ( breathing ( long enough ) ) ( ( ( to ( ( decrease ( ( the amount ) ( of oxygen ) ) ) ( in ( the ( ( blood and ) brain ) ) ) ) ) and ) ( to ( increase ( the ( carbon ( dioxide level ) ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (PP (IN With) (NP (NNS apneas))) (, ,) (NP (DT the) (VBG sleeping) (NN person)) (ADVP (RB repeatedly)) (VP (VBZ stops) (S (VP (VBG breathing) (ADVP (RB long) (RB enough)) (S (VP (VP (TO to) (VP (VB decrease) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN oxygen)))) (PP (IN in) (NP (DT the) (NN blood) (CC and) (NN brain))))) (CC and) (VP (TO to) (VP (VB increase) (NP (DT the) (NN carbon) (NN dioxide) (NN level))))))))) (. .)))
With apneas, the sleeping person repeatedly stops breathing long enough to decrease the amount of oxygen in the blood and brain and to increase the carbon dioxide level.
(ROOT (S (NP (DT The) (NN brain)) (VP (VBP stem) (S (NP (NP (NN monitor)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-))) (NP (NP (DT the) (NN level)) (PP (IN of) (NP (NP (NN carbon) (NN dioxide)) (PP (IN in) (NP (DT the) (NN blood)))))))) (. .)))