Use wordpress json api to get posts where post title contains some characters

i want to get all posts that contains specific characters using json api plugin in wordpress, i successes to get post where title is equal to string "mytitle", using this, http://mysite/json=get_posts&post_type=my_type&title=mytitle , but i want to get all posts that contains mytitle string , can any one help ?

via Chebli Mohamed