An apparatus in one example comprises a user wearable, non-encumbering, movement sensor and an analyzer. Iron oxide deposits may be removed from the surface of a titanium component by contacting the titanium component with the solvent composition of the invention. When air bubbles are detected, a second pump is activated to draw air from an air chamber provided in an air filter connected to the venous line and arranged downstream of the bubble sensor. By interaction between the coils and magnets, the lens holder is turned on a first axis while the light source and other components are secured. The interference detector is coupled to receive a portion of the interfering light to determine information representative of a location, an orientation, or a velocity of a portion of the patient or animal from the received light. The objectionable audio signal is detected while the call is in process and the user is prevented from hearing the objectionable audio signal while the objectionable audio signal is being detected.