I\'ve been trying to use:
$string=\"The Dr. is here!!! I am glad I\'m in the U.S.A. for the Dr. quality is great!!!!!!\";
preg_match_all(\'~.*?[?.!]~s\',$str
This is almost impossible since your example clearly indicates that punctuation characters that can be used in e.g. Dr., U.S.A etc, make it impossible to know where a sentence starts/ends.
You have to search the following characters to decide if a new sentence follows (starts after) the punctuation chars you are mentioning.