RecruitingDevice studyClinical Performance Evaluation of Native Whole Blood Samples of Patients on DOACs With the Perosphere ClotChek™The Perosphere ClotChek™ system consists of a hand-held, battery-operated blood coagulation instrument and disposable test cuvettes for use at the point-of-care (POC). The instrument performs a whole blood clotting time (WBCT) test using freshly drawn, non-citrated whole blood. The purpose of the present study is to characterize the performance of the Perosphere ClotChek™ as a quantitative measurement of the WBCT in patients taking one of the following Direct Oral Anticoagulants (DOACs), rivaroxaban or apixaban.