Abstract: A method and apparatus for remotely monitoring the location of an interventional medical device (IMD) using ultrasonic signals. Both the proximity and alignment of the IMD are calculated from ultrasound signals reflected off the tissue surface. The inclusion of an offset between the distal end of the IMD and the ultrasound transducer enables accurate position and alignment monitoring of when the IMD is in contact with, or very close to, the tissue surface. The timing of the reflected signal is used to measure proximity or contact. A comparison of the strength between multiple reflected signals is used to measure the alignment of the IMD in 3D space or perpendicularity to a given surface. The present invention may be used as a location indicator within a wide variety of IMDs, and in a wide variety of medical procedures.

Abstract: An ultrasound imaging system superimposes sectional views created from volumetric ultrasound data and the location data for an intervention device, such as a catheter. The position of an interventional medical device may be shown, in one or more views, relative to organs and tissues within a body as the interventional device is moved. The interventional device positional data is updated continuously and is superimposed on tissue images that may be updated less frequently, resulting in real-time or near real-time images of the interventional device relative to the tissues. The superimposed images permits medical personnel to perform procedures such as angiograms with minimal or no exposure of patients to x-rays and contrasting dye. The look and feel of the familiar fluoroscopy-like imaging may be maintained, or a three dimensional real-time, or near real-time projected image of the intervention medical device relative to an organ or tissue may be provided.

Abstract: A method and apparatus for remotely monitoring the location of an interventional medical device (IMD) which monitors changes in frequency response characteristics of a sensor. Embodiments of the present invention may use changes in the complex impedance properties of the sensor, at antiresonance, or changes in the resonant frequency of an LC circuit to indicate whether or not the IMD is in contact with a tissue surface. The present invention is adapted for use in conjunction with a wide variety of IMDs, and in a wide variety of medical procedures.