A catheter comprising: an elongate shaft 18 configured to be tracked to a treatment site within a vasculature, the elongate shaft 18 including a proximal portion 28 and a distal portion 32 extending from the proximal portion 28 to a distal opening at a distal end 32 of the shaft, the elongate shaft 18 having a shaft wall 34, the shaft wall 34 having an outer and inner surface, the shaft wall 34 inner surface defining a guide wire lumen 35; and a pressure sensor 38 having a first end coupled to the shaft wall 34 outer surface at the distal end 32 of the elongate shaft 18, characterized in that the pressure sensor 38 having a second end not coupled to the elongate shaft 18, wherein the second end of the pressure sensor 38 is spaced apart from the shaft wall 34 outer surface, such that at least a portion of the pressure sensor 38 is isolated from the bending stresses of the shaft wall 34 when the elongate shaft 18 is tracked to a treatment site within a vasculature, wherein the sensor 38 comprises a support portion 92 adjacent the first end of the sensor 38, and an elongate portion 94, wherein the support portion 92 is sized such that the support portion 92 elevates the elongate portion of the sensor 38 above the shaft wall 34 to create a void between the shaft wall 34 and the sensor 38, wherein support portion 92 and elongate portion 94 when taken together form a unitary or one-piece sensor 38, wherein the sensor is disposed within a pocket 50 on the distal end 32 of the elongate shaft 18, the pocket 50 defined by the shaft wall 34 outer surface and at least one sidewall 54 extending substantially perpendicular to the shaft wall 34, wherein the pocket 50 is exposed to the environment such that at least a portion of the sensor will be surrounded on all sides by a fluid when the elongate shaft 18 is tracked within the vasculature. an elongate shaft 18 configured to be tracked to a treatment site within a vasculature, the elongate shaft 18 including a proximal portion 28 and a distal portion 32 extending from the proximal portion 28 to a distal opening at a distal end 32 of the shaft, the elongate shaft 18 having a shaft wall 34, the shaft wall 34 having an outer and inner surface, the shaft wall 34 inner surface defining a guide wire lumen 35; and a pressure sensor 38 having a first end coupled to the shaft wall 34 outer surface at the distal end 32 of the elongate shaft 18, characterized in that the pressure sensor 38 having a second end not coupled to the elongate shaft 18, wherein the second end of the pressure sensor 38 is spaced apart from the shaft wall 34 outer surface, such that at least a portion of the pressure sensor 38 is isolated from the bending stresses of the shaft wall 34 when the elongate shaft 18 is tracked to a treatment site within a vasculature, wherein the sensor 38 comprises a support portion 92 adjacent the first end of the sensor 38, and an elongate portion 94, wherein the support portion 92 is sized such that the support portion 92 elevates the elongate portion of the sensor 38 above the shaft wall 34 to create a void between the shaft wall 34 and the sensor 38, wherein support portion 92 and elongate portion 94 when taken together form a unitary or one-piece sensor 38, wherein the sensor is disposed within a pocket 50 on the distal end 32 of the elongate shaft 18, the pocket 50 defined by the shaft wall 34 outer surface and at least one sidewall 54 extending substantially perpendicular to the shaft wall 34, wherein the pocket 50 is exposed to the environment such that at least a portion of the sensor will be surrounded on all sides by a fluid when the elongate shaft 18 is tracked within the vasculature.