Blood filtering metering device

Claim 1

A device for separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a filtering system of descending pore size to provide for successive removal of red blood cells without significant red blood cell lysis; a reactant pad for receiving said plasma sample from said filtering system; and removable means for removing overflow sample from contact with said reactant pad.

Claim 2

A device for separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a filtering system of descending pore size to provide for successive removal of red blood cells without significant red blood cell lysis; a reactant pad for receiving said plasma sample from said filtering system; and removable means for removing overflow sample from contact with said reactant pad.

Claim 5

A device for separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a reactant pad for receiving said plasma sample from said second fine filter; a perforated barrier below said reactant pad to prevent plasma flow until said reactant pad is saturated and to interrupt flow once said overflow has been absorbed; and an absorbent pad to receive plasma from said reactant pad upon overflow after saturation of said reactant pad.

Claim 6

A device for separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a reactant pad for receiving said plasma sample from said second fine filter; a perforated barrier below said reactant pad to prevent plasma flow until said reactant pad is saturated and to interrupt flow once said overflow has been absorbed; and an absorbent pad to receive plasma from said reactant pad upon overflow after saturation of said reactant pad.

Claim 17

A device for measuring an analyte in a blood sample involving separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a filtering and metering device comprising: a plastic mesh; a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a reactant pad for receiving said plasma sample from said second fine filter; a perforated barrier to prevent plasma flow until said reactant pad is saturated and to interrupt flow once said overflow has been absorbed; and an absorbent pad to receive plasma from said reactant pad upon overflow after saturation of said reactant pad; wherein said plastic mesh is bonded to said unperforated barrier and said coarse filter is reversibly bonded to said perforated barrier, whereby on pulling said mesh, said mesh, unperforated barrier and coarse filter are separated from said reactant pad and perforated barrier; an assay device comprising: a bibulous member support film; first and second bibulous members supported by said support film in tandem separated juxtaposition along their long axes, positioned under said reactant pad, so that upon removal of said unperforated film, said reactant pad acts as a bridge between said first and second bibulous members; and said perforated support is bonded to said bibulous member support film to urge said reactant pad in fluid transferring relationship with said bibulous strips upon removal of said unperforated support.

Claim 18

A device for measuring an analyte in a blood sample involving separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a filtering and metering device comprising: a plastic mesh; a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a reactant pad for receiving said plasma sample from said second fine filter; a perforated barrier to prevent plasma flow until said reactant pad is saturated and to interrupt flow once said overflow has been absorbed; and an absorbent pad to receive plasma from said reactant pad upon overflow after saturation of said reactant pad; wherein said plastic mesh is bonded to said unperforated barrier and said coarse filter is reversibly bonded to said perforated barrier, whereby on pulling said mesh, said mesh, unperforated barrier and coarse filter are separated from said reactant pad and perforated barrier; an assay device comprising: a bibulous member support film; first and second bibulous members supported by said support film in tandem separated juxtaposition along their long axes, positioned under said reactant pad, so that upon removal of said unperforated film, said reactant pad acts as a bridge between said first and second bibulous members; and said perforated support is bonded to said bibulous member support film to urge said reactant pad in fluid transferring relationship with said bibulous strips upon removal of said unperforated support.

Claim 19

A device for separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a reactant pad for receiving said plasma sample from said second fine filter; a movable mesh film in contact with and underneath said pad for receiving overflow and wiping the bottom of said pad when moved.

Claim 20

A device for separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a reactant pad for receiving said plasma sample from said second fine filter; a movable mesh film in contact with and underneath said pad for receiving overflow and wiping the bottom of said pad when moved.

Claim 21

A device for measuring an analyte in a blood sample involving separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a filtering and metering device comprising: a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a pull tab having an opening in which said first and second filters are fitted; a reactant pad for receiving said plasma sample from said second fine filter; a movable mesh underneath and incontact with said pad for receiving overflow sample and wiping said pad when moved; and an unperforated film underneath and affixed to said movable mesh to prevent sample from passing; and an assay device comprising: a bibulous member support film; first and second bibulous members supported by said support film in tandem separated juxtaposition along their long axes, positioned under said reactant pad, so that upon removal of said unperforated film, said reactant pad acts as a bridge between said first and second bibulous members.

Claim 22

A device for measuring an analyte in a blood sample involving separating cells from blood to produce plasma and metering a predetermined amount of plasma to a reactant pad without significant red blood cell lysis, said device comprising: a filtering and metering device comprising: a first coarse filter to remove from about 10% to 90% of the red blood cells in a blood sample; a second fine filter to remove substantially all of the remaining red blood cells in said sample to provide a plasma sample; a pull tab having an opening in which said first and second filters are fitted; a reactant pad for receiving said plasma sample from said second fine filter; a movable mesh underneath and incontact with said pad for receiving overflow sample and wiping said pad when moved; and an unperforated film underneath and affixed to said movable mesh to prevent sample from passing; and an assay device comprising: a bibulous member support film; first and second bibulous members supported by said support film in tandem separated juxtaposition along their long axes, positioned under said reactant pad, so that upon removal of said unperforated film, said reactant pad acts as a bridge between said first and second bibulous members.