The kavana we have when we put on tefilin is בחוזק יד הוציאנו השם ממצרים - with a strong arm Hashem took us out of Egypt. Due to the Hashem's "strong hand" that was revealed in Egypt we can see that all of our non-spiritual desires are NONSENSE and that the love and fear of Hashem in our hearts [next to the תפילין של יד] should be elevated to our minds תפילין של ראש.
[Based on Mei Marom page 26]
Love and blessings and may the message of the tefilin penetrate all of our hearts and minds:-)!