초록 ▼

A platelet collection device comprising a centrifugal spin-separator container with a cavity having a longitudinal inner surface. A float in the cavity has a base, a platelet collection surface above the base, an outer surface. The float density is below the density of erythrocytes and above the den

A platelet collection device comprising a centrifugal spin-separator container with a cavity having a longitudinal inner surface. A float in the cavity has a base, a platelet collection surface above the base, an outer surface. The float density is below the density of erythrocytes and above the density of plasma. The platelet collection surface has a position on the float which places it below the level of platelets when the float is suspended in separated blood. During centrifugation, a layer of platelets or buffy coat collects closely adjacent the platelet collection surface. Platelets are then removed from the platelet collection surface. Movement of a float having a density greater than whole blood through the sedimenting erythrocytes releases entrapped platelets, increasing the platelet yield.

대표청구항 ▼

The invention claimed is: 1. A method for collecting platelets from a patient's blood for application to the patient in a medical treatment, comprising: providing a container having a sidewall, a bottom, and a top portion defining a volume; positioning a float within the volume at a first axial pos

The invention claimed is: 1. A method for collecting platelets from a patient's blood for application to the patient in a medical treatment, comprising: providing a container having a sidewall, a bottom, and a top portion defining a volume; positioning a float within the volume at a first axial position; placing the patient's blood in the volume; moving the float within the volume and through the patient's blood; collecting at least a portion of an erythrocyte volume of the patient's blood; forming a thin layer of the erythrocytes on a surface of the float; sedimenting platelets on the thin layer of erythrocytes formed on the surface of the float; moving a plunger relative to the float; and withdrawing the platelets from the sedimented platelets between the float and the plunger; wherein forming the thin layer of erythrocytes includes positioning the surface below a platelet layer. 2. The method of claim 1, further comprising: defining a collection area including: providing an outer rim of the float having a first height; and providing a top wall of the float defining a depressed center having a point below the first height of the outer rim. 3. The method of claim 2, further comprising: providing an extraction passage defined by the float; and extracting the platelets through the extraction passage; wherein the extraction passage is in communication with the collection area. 4. The method of claim 3, further comprising: interconnecting a needle with the extraction passage. 5. The method of claim 1, further comprising: providing a float of only polyethylene and polycarbonate. 6. The method of claim 1, further comprising: providing a float of only a substantially rigid material; and fixing the float at a selected position within the provided container in the absence of the force. 7. A method for collecting platelets from a patient's blood for application to the patient in a medical treatment, comprising: providing a container; positioning the patient's blood in the container; positioning a float in the container, wherein the float is positioned near a distal end of the container between the patient's blood in the container and a bottom wall of the container; subjecting the container, the float, and the patient's blood to centrifugal forces substantially toward the bottom wall of the container; moving the float through the patient's blood as it is centrifuged; forming a platelet layer near the float; moving a plunger relative to the float; and withdrawing the platelets from the platelet layer from between the float and the plunger. 8. The method of claim7, further comprising: forming a first layer of a portion of the patient's blood directly on a support surface of the float; and forming the platelet layer on the first layer. 9. The method of claim 7, wherein a support surface defines at least a portion of a platelet collection surface. 10. The method of claim 9, further comprising: moving the platelet collection surface immediately below the platelet layer. 11. The method of claim 7, further comprising: defining a collection area including: providing an outer rim of the float having a first height; and providing a top wall of the float defining a depressed center having a point below the first height of the outer rim. 12. The method of claim 7, further comprising: providing a float of only a substantially rigid material; and fixing the float at a selected position within the provided container in the absence of the force. 13. The method of claim 12, further comprising: engaging the float with a flexible tube positioned in the container. 14. The method of claim 7, wherein the float includes a first portion and a second portion and the collection area is defined between the first portion and the second portion.