According to an aspect of the present disclosure, a surgical instrument for operating on tissue is provided. The surgical instrument includes an end effector including a first tissue engaging member and a second tissue engaging member in juxtaposed relation to the first tissue engaging member; a gap determination element operatively associated with each of the first tissue engaging member and the second tissue engaging member for measuring a gap distance between the first tissue engaging member and the second tissue engaging member; and a tissue contact determining element operatively associated with a respective tissue contacting surface of at least one of the first tissue engaging member and the second tissue engaging member. The present disclosure also relates to methods of using the surgical instrument.