US Patent 11389624 Blood collection devices, systems, and methods

An access system can include a connector couplable with a catheter assembly having a catheter tube that can be positioned in a blood vessel of a patient. The access system can include a reinforcement member and a cannula couplable with a fluid collection device. The cannula can include a polymeric tube that defines a distal tip and a support tube that is stiffer than the polymeric tube and encompasses a portion of the polymeric tube. The support tube can define an inner diameter that is marginally larger than an outer diameter of the polymeric tube so as to prevent kinking of the portion of the polymeric tube that is encompassed by the support tube when the polymeric tube experiences proximally and distally directed compressive forces.