A guidewire system for treating a patient may include a sensor assembly for detecting a physiological characteristic of a patient and a hypotube sized for insertion into vasculature of the patient and having an integrated sensor mount formed therein for predictably locating the sensor during assembly. The hypotube may also have a wall structure and a lumen, and the sensor mount may be formed within the wall structure of the hypotube and may include a first mechanical stop configured to limit movement of the sensor assembly in at least a first dimension and a second mechanical stop configured to limit movement of the sensor assembly in at least a second dimension. A sensor housing may be disposed about the sensor mount and may have a window formed therein to provide fluid communication between the sensor assembly and an environment outside the hypotube.
