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

Claim 3:
4. 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 pair of electrodes disposed in the shaft of the needle for measuring impedance of any blood in the shaft;
determining by the puncture-differentiation means impedance from electrical resistivity of the blood between the pair of electrodes disposed in the shaft of the needle;
comparing by the puncture-differentiation means the impedance to that expected for venous blood or arterial blood; and
indicating by the puncture-differentiation means whether the impedance is consistent with venous blood or arterial blood, thereby differentiating between the venipuncture and the arterial puncture, respectively.