Medtronic, Inc.

Lucent Medical Systems, Inc.

Gary Brian Sanders

Robert N Golden

William Jeffrey Bertrand

Lori C Speckman

Steve Vincent

David R Haynor

Christopher P Somogyi

Samuel Peter Andreason

Daniel R Morris

Dan Morris

A medical system tracks the position of a medical instrument within a body of a patient. The medical instrument includes an electromagnet structure having an inductor coil wound around a core. A control circuit applies a low frequency excitation signal across the inductor coil. The inductor coil and the core generate a magnetic field. A plurality of sensors sense parameters of the generated magnetic field and produce sensor signals. The control circuit calculates the position of the medical instrument based on the produced sensor signals.

Low-frequency electromagnetic tracking

The invention is directed toward a magnetic valve reader used as an indicator tool. The magnetic valve reader determines a location and an orientation for a magnetic indicator device to indicate a device setting of an implantable medical device. The implantable medical device includes the magnetic indicator device coupled to a valve on the implantable medical device. External magnetic fields, specifically the Earth's magnetic field, may interfere with the compass and create an incorrect device setting indication. The electronic reader estimates the external magnetic fields to subtract the estimate from received data to minimize any influence that external magnetic field has on the accuracy of the device setting measurement.

Electronic valve reader

A device to detect the location of a plurality of magnets uses a plurality of magnetic sensors, having sensor elements arranged in a known fashion. Each sensor element senses the magnetic field strength generated by each of the plurality of magnets and provides data indicative of the direction of the magnets in a three-dimensional space. The device uses fundamental equations for electricity and magnetism that relate the measured magnetic field strength to the location and strength of the magnetic dipole for each of the plurality of magnets. The device may use an iterative process to determine the actual location and orientation of each magnet. An initial estimation of the location and orientation of each magnet results in the generation of predicted magnetic field values. The predicted magnetic field values are compared with the actual measured values provided by the magnetic sensors. Based on a difference between the predicted values and the measured values, the device estimates a new location for each of the magnets and calculates new predicted magnetic field strength values. The iteration process continues until the predicted values match the measured values within a desired degree of tolerance. At this point, the estimated location and orientation of each of the magnets matches the actual location within a predetermined degree of tolerance.

System and method to determine the location and orientation of an indwelling medical device

Growing community of inventors

Kirkland, WA, United States of America

Gary Brian Sanders