Patent ID: 8328720

Claim:
A method of determining a prothrombin time, comprising: applying a mediator to a stratum corneum; penetrating the stratum corneum to allow the mediator to enter a region containing interstitial fluid and interact with at least one capillary, causing blood and/or blood components to leak from the at least one capillary into the region containing interstitial fluid; measuring a characteristic affected by the blood and/or blood components in the region containing interstitial fluid which correlates to the prothrombin time; and applying a coagulation activator to the stratum corneum, and wherein penetrating the stratum corneum also allows the coagulation activator to enter the region containing interstitial fluid, and the blood and/or blood components which have been caused to leak from the at least one capillary into the region containing interstitial fluid can interact with the coagulation activator.