Abstract: An volume of a patient can be mapped with a system operable to identify a plurality of locations and save a plurality of locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be correlated to a three dimensional location of the electrode at the time of the sensing or measurement. Therefore, a map of a volume can be determined based upon the sensing of the plurality of points without the use of other imaging devices. An implantable medical device can then be navigated relative to the mapping data.

Abstract: A system for detecting a protrusion of a conductor within an anatomy is provided. The system can include a conductor, an insulator and a protrusion module to indicate a protrusion if the conductor protrudes from the insulator within the anatomy. The conductor can comprise a guide wire, a stylet, a pacing lead, a defibrillation lead, or other conductive instruments. The insulator can comprise a catheter, a sheath a cannula or other insulative instruments. The system can detect protrusion based on an impedance or an electrogram measurement.

Abstract: Oxygen saturation data is monitored during a predefined window to obtain a measurement of circulation delay. The measured circulation delay is used as a basis for determining therapies, including overdrive pacing. In some embodiments, circulation delay is used to identify patients that will benefit from overdrive pacing as a therapy for sleep disordered breathing.