A catheter assembly includes a catheter, a tubular structure affixed to an exterior surface of the catheter, and a stabilizing cuff affixed to, and at least partially embedded within, the tubular structure. A refracting lens is mounted adjacent the opening. The brace compliance monitor may also include a secondary sensor such as a tilt sensor, a pressure sensor, a force sensor, an acceleration sensor, or a velocity sensor. Specifically, The vacuum chamber is evacuated to a low pressure and refilled with a preheated inert gas.