Apparatus and method for measuring hemostatic properties of platelets

Claim 1

Apparatus for clinically testing the bleeding time of a human subject comprising, in combination: a. a blade holder having a handle, a lower horizontal planar bearing surface, and a blade receiving portion open at said planar bearing surface; b. means on said blade holder for mounting a cutting blade on said blade receiving portion at a predetermined, specific location; c. a cutting blade having a pointed tip and an angled cutting edge extending away from said tip, said blade being mounted on said blade holder by said mounting means in a predetermined, specific position in which said blade tip protrudes beyond said horizontal, planar bearing surface of said blade holder by a predetermined, specific distance, the plane of said blade being perpendicular to said planar bearing surface; and d. a template having parallel upper and lower horizontal planar surfaces, and walls forming a straight, vertical blade slit open at said upper and lower planar surfaces, the width of said slit being slightly greater than the width of said cutting blade, said blade tip being removably inserted through said template slit, and said blade holder planar bearing surface being slidably positioned flush against said template upper horizontal planar surface, whereby the tester may firmly press the template against the volar side of the subject''s forearm with one hand, grip the blade holder with the other hand, insert the blade tip vertically at one end of the template slit, pEnetrate the subject''s skin with the blade tip to a depth at which the blade holder planar bearing surface is positioned flush against the template upper horizontal surface, draw the blade along the length of the template slit to the other end of the slit, withdraw the blade vertically from the slit, remove the template, and measure the time which elapses until the resulting bleeding ceases.

Claim 4

A method for clinically testing the bleeding time of a human subject comprising the following steps: a. mounting a cutting blade on a blade holder which has a lower horizontal planar bearing surface, said blade being mounted in a predetermined, specific position in which the cutting tip of said blade protrudes beyond said horizontal planar bearing surface of said blade holder by a predetermined, specific distance; b. pressing a template against the volar side of the subject''s forearm, said template having a blade slit formed entirely therethrough, said blade slit having a predetermined, specific length and depth; c. inserting said blade cutting tip through said template blade slit at one end of said slit, and vertically penetrating the subject''s skin by pressing said blade holder downwardly until said blade holder lower horizontal planar bearing surface is positioned flush against the upper horizontal surface of said template; d. drawing said blade holder smoothly and rapidly along the length of said template blade slit to the other end of said slit to cause said blade to make an incision of a predetermined, specific, uniform length and depth in the subject''s skin; e. withdrawing said blade vertically from the subject''s skin and removing said template from the subject''s skin; and f. measuring the time which elapses between when the blade is withdrawn and when the resulting bleeding ceases.

Claim 5

A method for clinically testing the bleeding time of a human subject comprising the following steps: a. mounting a cutting blade on a blade holder which has a lower horizontal planar bearing surface, said blade being mounted in a predetermined, specific position in which the cutting tip of said blade protrudes beyond said horizontal planar bearing surface of said blade holder by a predetermined, specific distance; b. pressing a template against the volar side of the subject''s forearm, said template having a blade slit formed entirely therethrough, said blade slit having a predetermined, specific length and depth; c. inserting said blade cutting tip through said template blade slit at one end of said slit, and vertically penetrating the subject''s skin by pressing said blade holder downwardly until said blade holder lower horizontal planar bearing surface is positioned flush against the upper horizontal surface of said template; d. drawing said blade holder smoothly and rapidly along the length of said template blade slit to the other end of said slit to cause said blade to make an incision of a predetermined, specific, uniform length and depth in the subject''s skin; e. withdrawing said blade vertically from the subject''s skin and removing said template from the subject''s skin; and f. measuring the time which elapses between when the blade is withdrawn and when the resulting bleeding ceases.