Patent ID: 11918795
Assignee: BARD ACCESS SYSTEMS, INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 4:
5. A method for differentiating between a venipuncture and an arterial puncture, comprising:
accessing a vein or an artery of a patient by way of a puncture with a puncturing device, the puncturing device including:
a needle including a shaft, a lumen defined by an inner diameter of the shaft, and a tip in a distal-end portion of the shaft; and
a hub disposed over a proximal-end portion of the shaft, the hub including a blood-flashback chamber in fluid communication with the lumen of the needle configured to capture an aliquot of blood in the blood-flashback chamber at a time of accessing the vein or the artery of the patient by way of the puncture with the needle;

consulting a puncture-differentiation means for differentiating between the venipuncture and the arterial puncture, the puncture-differentiation means including a chemical-based oxygen sensor integrated with the hub for colorimetrically indicating oxygen in any captured blood in the blood-flashback chamber;
colorimetrically indicating by the puncture-differentiation means a concentration of the oxygen in the captured blood with the chemical-based oxygen sensor using a chemical formulation disposed in the blood-flashback chamber, the chemical formulation including an alkaline buffer and indigo carmine as a color agent;
comparing the concentration of the oxygen in the captured blood colorimetrically indicated by the chemical formulation against a comparator on the hub of the puncturing device; and
colorimetrically determining whether the concentration of the oxygen in the captured blood is consistent with venous blood or arterial blood.