Abstract: The application relates to vascular catheters, in particular to vascular catheter systems (100) which are configured to mix blood. Aspects relate to a mixer sheath (110) for a vascular catheter, a method of manufacturing a mixer sheath, a catheter sheath, a catheter, a method of deploying a vascular catheter, a method of removing a vascular catheter, a method of deploying one or more blood mixing elements, a method of using a catheter system and a method of reversing the deployment of a blood mixing element. The mixer sheath comprises a tube having a wall patterned with a line of weakness (212) which is configured to cause buckling of a portion of the tube wall when a longitudinal compression force is applied to the tube to form a blood mixing element (111) which extends radially outwards with respect to a location of the portion of the tube wall prior to buckling.

Abstract: A catheter for insertion into a blood vessel, the catheter having a sampling part arranged to capture a blood sample at a plurality of locations along a length of the blood vessel and an apparatus arranged to analyze blood taken from a plurality of locations along the length of the blood vessel and to provide a profile of concentration levels along the length of the blood vessel.