Fig. 1.

Serial changes of the ACL-TOP second-derivative curve and the levels of factor VIII and von Willebrand factor. (a) Before the desmopressin loading test. (b) After 15 min. (c) After 2 h. (d) After 6 h. An abnormal biphasic curve on the second-derivative curve (light blue) was detected in a patient with von Willebrand factor deficiency. A shoulder-type abnormal curve was detected at 2 and 6 h after the desmopressin loading test. APTT, activated partial thromboplastin time; FVIII, factor VIII; vWF, von Willebrand Factor.