Apparatus and method for minimally invasive blood sampling

A blood sampling device for penetrating skin to sample blood therefrom, comprising:

• (a) a housing;
• (b) a blade structure operatively retractably connected to the housing, the blade structure having three planar blades each including a cutting edge, the blades abutting one another to form a rigid joint from which the blades extend such that the cutting edges are remote from the rigid joint, the blade structure having a distal portion in which the distance from the rigid joint to each cutting edge decreases towards a distal end terminating at a sharp point, each blade forming an angle less than 180 degrees with blades neighboring thereto;
• (c) one to three capillaries, each capillary extending along the rigid joint at the distal portion of the blade structure and being cradled between two blades, each capillary having a distal opening proximate to the distal end of the blade structure for blood to enter from the skin;
• and
• (d) an actuator associated with the blade structure for driving the blade structure to incise the skin and retracting the distal end of the blade structure into the housing after incision.

A method for sampling blood from skin, comprising:

• driving a blade structure from a housing to penetrate the skin, the blade structure having at least two blades each including a cutting edge, the blades abutting one another to form a rigid joint from which the blades extend such that the cutting edges are remote from the rigid joint, the blade structure each having a distal portion in which the distance from the rigid joint to the cutting edge decreases towards a distal end to terminate at a sharp point, each blade having a center plane such that each center plane forms an angle less than 180 degrees with at least one neighboring center plane of blades neighboring thereto, such that the tissue of the skin slides along the surface of the blades to reduce tearing and such that the tendency of the blade structure to flex is reduced as the distal end of the blade structure is driven into the skin to yield blood therefrom;
• stopping the blade structure after the blade structure has penetrated the skin to a distance reaching blood vessels to cause bleeding;
• and
• withdrawing the blade structure from the skin to allow blood to exit the skin.

A blood sampling device for penetrating skin to sample blood therefrom, comprising:

• (a) a housing;
• and
• (b) a blade structure retractably connected in the housing, the blade structure having at least two blades each including a cutting edge, the blades abutting one another to form one or more rigid joints such that the cutting edges are remote from the corresponding one or more rigid joints, the blade structure having a distal portion in which for each blade the distance from the rigid joint to the cutting edge associated with the blade decreases towards a distal end of the blade structure, to terminate at a sharp point, such that a plane that passes through the mid-line of a blade (center plane) forms an angle less than 180 degree with at least one neighboring center plane of blades neighboring thereto, thereby decreasing the tendency of the blade structure to flex as the distal end of the blade structure is driven into the skin to yield blood therefrom;
• wherein the blades are generally planar and extend radially from the rigid joint;
• and
• (c) at least one capillary, the capillary extending along the rigid joint at the distal portion of the blade structure and being cradled between two blades that abut at an angle less than 180 degrees, the capillary having a distal opening proximate to the distal end of the blade structure.