METHODS AND DEVICES FOR MONITORING PLATELET FUNCTION

1 . A method of monitoring platelet function comprising: passing blood removed from a mammal through a passageway comprising (i) a shear generating restriction to generate a platelet mass in the passageway and (ii) a platelet aggregate trap; and monitoring the flow or composition of the blood in the passageway to detect formation of the platelet mass, wherein the blood passes through the passageway in one direction and only one time.

2 . The method of claim 1 , wherein the platelet aggregate trap is positioned in the shear generating restriction.

3 . The method of claim 1 , wherein the platelet aggregate trap is positioned downstream of the shear generating restriction.

4 . The method of claim 1 , wherein the platelet aggregate trap is a spring.

5 - 6 . (canceled)

7 . The method of claim 1 , wherein the amount of time to form a platelet mass is measured.

8 . The method of claim 4 , wherein the spring is mounted transversely to the passageway.

9 . The method of claim 1 , wherein the flow of the blood in the passageway is monitored.

10 . The method of claim 9 , wherein the flow is monitored by monitoring the pressure of the blood in the passageway.

11 . The method of claim 10 , wherein the pressure is monitored with a pressure transducer.

12 . The method of claim 1 , wherein less than 0.4 ml of blood is removed from the body of the mammal.

13 . The method of claim 1 , wherein less than 20 μl of blood passes through the passageway.

14 . The method of claim 1 , wherein the blood is whole blood.

15 . The method of claim 1 , wherein the blood is fractionated blood.

16 . The method of claim 1 , wherein the mammal is treated with an anti-platelet agent.

17 . The method of claim 1 , wherein the platelet mass that forms is substantially depleted in fibrin in comparison to a normal clot.

18 . A device for monitoring platelet function, comprising: a fluid-tight material forming a passageway; a pump functionally linked to the passageway for pumping blood through the passageway; a shear generating restriction within the passageway; a spring within the passageway and positioned downstream of the shear generating restriction; and a detector for detecting the flow of blood through the passageway to detect formation of the platelet mass.

19 . A method of monitoring platelet function comprising: passing blood removed from a mammal through a passageway comprising (i) a shear generating restriction to generate a platelet mass in the passageway and (ii) a platelet aggregate trap; and monitoring the flow or composition of the blood in the passageway to detect formation of the platelet mass, wherein the blood is recirculated through the passageway and the blood flows only one direction through the passageway.

20 . The method of claim 19 , wherein the blood flows in a generally circular circuit that comprises the passageway.

21 . The method of claim 19 , wherein the blood flows alternately through the passageway and through a bypass channel, the bypass channel allowing blood that has flowed through the passageway previously to flow through the passageway again.

22 . The method of claim 19 , wherein the platelet aggregate trap is positioned in the shear generating restriction.

23 - 41 . (canceled)