Patent ID: 7071001

Claim:
An in vitro bleeding time determination device comprising: a housing having an internal chamber with a longitudinal axis, an inlet in fluid communication with the internal chamber disposed at a first elevation, and a single outlet in fluid communication with the internal chamber disposed at a second elevation below the first elevation, wherein the single outlet has a flowpath perpendicular to the longitudinal axis of the internal chamber that permits fluid to flow out from the chamber; a sheet of material spanning the flowpath through the outlet, the sheet of material having a sheet thickness and having an inner region surrounded by a peripheral region, the inner region having a rectangular opening spanning the sheet thickness, the opening having a width of from about 60 microns to about 120 microns and a length of less than 500 microns, the rectangular opening being disposed such that the opening is substantially horizontal along its length when the device is in operation; and a coating over at least a portion of a first side of the sheet of material, the coating comprising collagen type I, fibrinogen, fibronectin, and von Willebrand factor, and a substantial absence of type IV collagen.