for its success on a patient viewer 
(ROOT (PP (IN for) (NP (NP (PRP$ its) (NN success)) (PP (IN on) (NP (DT a) (NN patient) (NN viewer))))))
(ROOT (PP (IN ) (NP (NP (PRP$ ) (NN )) (PP (IN ) (NP (DT ) (NN ) (NN ))))))