Apparatus and method for the autotransfusion of blood

DETAILED DESCRIPTION In accordance with the primary purpose of the present invention, there is provided a high speed autotransfusion filter for rapid processing, thorough cleansing, and returning of a patient's blood during an operation.
In this invention blood is removed, usually continuously, from a body cavity and first conveyed to a filter for removal of gross particulate refuse.
The filtered blood is then pumped to filter of this invention where it enters an inlet port.
The filter body is formed by attaching two plates along their perimeter.
The plates are designed and attached to form a hollow interior region within the filter.
An inlet port is placed proximate the center of a first plate.
A partition is placed between the two plates to divide the interior region into a first and second filtration zone such that when filtered blood flows through the first filtration zone around the perimeter of the partition in an outward radial direction, and into the second filtration zone.
A washing zone is located intermediate the filtration zones, where the blood cells contact an aqueous saline wash which serves to remove anticoagulant adhering to blood cells (white, red, and platelets) to prevent build up of anticoagulant in the patient.
A first discharge chamber is located on the first plate in an annular configuration around the inlet port.
This chamber is separated from the interior region of the filter by a first membrane selected to pass the desired filtrate while leaving the cells to be collected on the membrane in the first filtration zone which move to a washing zone at the perimeter of the partition which supplies shear energy to urge concentrated blood cells along the membranes.
An aqueous saline solution is injected into the wash zone to both clean the blood cells and to dilute the blood mixture.
Leaving the washing zone, the mixture passes through the second filtration zone where the fluid is again removed and the blood mixture is recovered through an outlet in plate two.
The second filtration zone is formed by interposing a second membrane in the interim region between the partition and the second plate