Abstract: An implantable medical device configured to be compatible with the environment inside an MRI machine. The implantable medical device includes a housing constructed of an electrically conductive material and pulse generation circuitry within the housing for generating electrical voltage pulses. The implantable medical device further includes a first conductor that is configured to transmit the electrical voltage pulses from the pulse generation circuitry to a patient's cardiac tissue and a second conductor that is configured to provide an electrically conductive path from the patient's cardiac tissue back to the pulse generation circuitry. The implantable medical device further includes a selectively interruptible electrically conductive path connecting the pulse generation circuitry with the housing.

Abstract: An MR compatible injection catheter is provided. The MR compatible injection catheter includes an inner shaft; an outer shaft circumferentially surrounding the inner shaft; and a means for actively tracking the catheter in a patient within a MRI. The means for actively tracking the catheter includes two or more tracking coils in the outer shaft. The inner shaft is configured to move relative to the outer shaft and includes an inner tube circumferentially surrounded by an outer tube.

Abstract: An MR compatible RF transseptal needle system is provided. The transseptal needle system includes a transseptal needle having a main cannula portion and a distal tip portion; and a delivery tool with a distal tip electrode. In some embodiments the transseptal needle system further includes a linear position measurement mechanism including a wiper member; and two or more conductive strip members.

Abstract: A method for projecting a broad tracking signal received by an inductively coupled element, such as a transformer during an MR tracking sequence is provided. By varying projection planes, the signal acquired from the transformer along the transmission line can be used to depict the body of the actively tracked medical device, such as the shaft or deflection region of a catheter. This may be achieved by interpolating a line between the position of the transformer element within the transmission line and the tracking coil. A curvature may be added to the line segment and gradually increased until the arc length of the line segment is approximately equal to the predefined length. The direction of the curve may be determined by virtually connecting the transformer position to the distal most tracking coil position, then the curve of the line segment is increased towards the proximal coil position.

Abstract: An implantable medical device configured to be compatible with the environment inside an Mill machine. The implantable medical device includes a housing constructed of an electrically conductive material and pulse generation circuitry within the housing for generating electrical voltage pulses. The implantable medical device further includes a first conductor that is configured to transmit the electrical voltage pulses from the pulse generation circuitry to a patient's cardiac tissue and a second conductor that is configured to provide an electrically conductive path from the patient's cardiac tissue back to the pulse generation circuitry. The implantable medical device further includes a selectively interruptible electrically conductive path connecting the pulse generation circuitry with the housing.

Abstract: An implantable medical device configured to be compatible with the environment inside an MRI machine. The implantable medical device includes a housing constructed of an electrically conductive material and pulse generation circuitry within the housing for generating electrical voltage pulses. The implantable medical device further includes a first conductor that is configured to transmit the electrical voltage pulses from the pulse generation circuitry to a patient's cardiac tissue and a second conductor that is configured to provide an electrically conductive path from the patient's cardiac tissue back to the pulse generation circuitry. The implantable medical device further includes a selectively interruptible electrically conductive path connecting the pulse generation circuitry with the housing.

Abstract: A method for projecting a broad tracking signal received by an inductively coupled element, such as a transformer during an MR tracking sequence is provided. By varying projection planes, the signal acquired from the transformer along the transmission line can be used to depict the body of the actively tracked medical device, such as the shaft or deflection region of a catheter. This may be achieved by interpolating a line between the position of the transformer element within the transmission line and the tracking coil. A curvature may be added to the line segment and gradually increased until the arc length of the line segment is approximately equal to the predefined length. The direction of the curve may be determined by virtually connecting the transformer position to the distal most tracking coil position, then the curve of the line segment is increased towards the proximal coil position.

Abstract: An implantable medical device configured to be compatible with the environment inside an MRI machine. The implantable medical device includes a housing constructed of an electrically conductive material and pulse generation circuitry within the housing for generating electrical voltage pulses. The implantable medical device further includes a first conductor that is configured to transmit the electrical voltage pulses from the pulse generation circuitry to a patient's cardiac tissue and a second conductor that is configured to provide an electrically conductive path from the patient's cardiac tissue back to the pulse generation circuitry. The implantable medical device further includes a selectively interruptible electrically conductive path connecting the pulse generation circuitry with the housing.

Abstract: An actively tracked medical device comprising: a dilator having an inner tubular main body having a distal end and a proximal end, said tubular main body including at least first and second receiving channels positioned in a spaced apart relationship on an outer surface of said tubular main body; a region at the distal end of said tubular main body for supporting one or more tracking coils; an atrumatic tip portion operably coupled and positioned distal to said main body; a lumen extending through said tubular main body, said tip support and said atraumatic tip portion; and an outer polymer body having first and second ends, said outer polymer body operably covering said inner tubular main body and said tracking coils, said first end terminating adjacent a proximal end of said atraumatic tip portion and said second end terminating adjacent said hub.

Abstract: A composite tracking system for a medical device comprises a field location tracking system including at least one field location sensor structured to be coupled to a medical device, a magnetic resonance tracking system including at least one tracking coil structured to be coupled to a medical device, and a composite tracking processor operably coupled to the field location tracking system and the magnetic resonance tracking system. The composite tracking processor is operable to receive and process field location parameters from the field location tracking system and positional coordinates from the magnetic resonance tracking system to register a field location coordinate system to a magnetic resonance coordinate system.

Abstract: An implantable medical device configured to be compatible with the environment inside an MRI machine. The implantable medical device includes a housing constructed of an electrically conductive material and pulse generation circuitry within the housing for generating electrical voltage pulses. The implantable medical device further includes a first conductor that is configured to transmit the electrical voltage pulses from the pulse generation circuitry to a patient's cardiac tissue and a second conductor that is configured to provide an electrically conductive path from the patient's cardiac tissue back to the pulse generation circuitry. The implantable medical device further includes a selectively interruptible electrically conductive path connecting the pulse generation circuitry with the housing.

Abstract: A composite tracking system for a medical device comprises a field location tracking system including at least one field location sensor structured to be coupled to a medical device, a magnetic resonance tracking system including at least one tracking coil structured to be coupled to a medical device, and a composite tracking processor operably coupled to the field location tracking system and the magnetic resonance tracking system. The composite tracking processor is operable to receive and process field location parameters from the field location tracking system and positional coordinates from the magnetic resonance tracking system to register a field location coordinate system to a magnetic resonance coordinate system.

Abstract: A method of calibrating field location tracking to magnetic resonance tracking is provided. The method of calibration field location tracking includes moving a medical device throughout a plurality of points within a patient volume; tracking the medical device with a field location tracking system and a magnetic resonance tracking system; calculating a plurality of magnetic resonance tracking locations; determining a plurality of field location parameters that correspond to the plurality of magnetic resonance tracking locations; and creating a transfer function that maps the field location parameters to the magnetic resonance tracking locations, wherein the transfer function registers a field location coordinate system to a magnetic resonance coordinate system.

Abstract: A method of using a MR compatible deflectable catheter is provided. The MR compatible deflectable catheter includes a steerable sheath having a tubular shaft. The tubular shaft receives first and second longitudinal movement wires at a distal end thereof. A control handle is coupled to a proximal end of the first and second longitudinal movement wires and causes longitudinal movement of the wires. Longitudinal movement of the wires causes the catheter to deflect approximately 180 degrees.

Abstract: An MR compatible deflectable catheter and method of using the same is provided. The MR compatible deflectable catheter includes a steerable sheath having a tubular shaft. The tubular shaft receives first and second longitudinal movement wires at a distal end thereof. A control handle is coupled to a proximal end of the first and second longitudinal movement wires and causes longitudinal movement of the wires.

Abstract: A method of using a MR compatible deflectable catheter is provided. The MR compatible deflectable catheter includes a steerable sheath having a tubular shaft. The tubular shaft receives first and second longitudinal movement wires at a distal end thereof. A control handle is coupled to a proximal end of the first and second longitudinal movement wires and causes longitudinal movement of the wires. Longitudinal movement of the wires causes the catheter to deflect approximately 180 degrees.

Abstract: An MRI compatible electrode circuit construct is provided. The construct includes at least two filter components constructed from an electrode wire. One filter component may be a resonant LC filter at or near an electrode/wire interface that resolves the issue of insufficient attenuation by effectively blocking the RF induced current on the wire from exiting the wire through the electrode. The second filter component may include one or more non-resonant filter(s) positioned along the length of the electrode wire that resolve(s) the issue of excessive heating of the resonant LC filter by significantly attenuating the current induced on the wire before it reaches the resonant LC filter. The non-resonant filter(s) may also attenuate the RF current reflected from the resonant LC filter thereby resolving the issue of the strong reflected power from the resonant filter and the associated dielectric heating.

Abstract: An MRI compatible lead assembly construct is provided. The construct includes at least two filter components constructed from an electrode wire. One filter component may be a resonant LC filter proximate an electrode that resolves the issue of insufficient attenuation by effectively blocking the RF induced current on the wire from exiting the wire through the electrode. The second filter component may include a non-resonant filter(s) positioned along the length of the electrode wire by co-radially winding at least two electrode wires. The non-resonant filter resolve(s) the issue of excessive heating of the resonant LC filter by significantly attenuating the current induced on the wire before it reaches the resonant LC filter.

Abstract: An MRI compatible lead assembly construct is provided. The construct includes at least two filter components constructed from an electrode wire. One filter component may be a resonant LC filter at or near an electrode/wire interface that resolves the issue of insufficient attenuation by effectively blocking the RF induced current on the wire from exiting the wire through the electrode. The second filter component may include one or more non-resonant filter(s) positioned along the length of the electrode wire that resolve(s) the issue of excessive heating of the resonant LC filter by significantly attenuating the current induced on the wire before it reaches the resonant LC filter. The non-resonant filter(s) may also attenuate the RF current reflected from the resonant LC filter thereby resolving the issue of the strong reflected power from the resonant filter and the associated dielectric heating.

Abstract: An MRI compatible electrode circuit construct is provided. The construct includes at least two filter components constructed from an electrode wire. One filter component may be a single or multiple layer resonant LC filter positioned proximate an electrode that resolves the issue of insufficient attenuation by effectively blocking the RF induced current on the wire from exiting the wire through the electrode. The second filter component may include one or more non-resonant filter(s) positioned along the length of the electrode wire that resolve(s) the issue of excessive heating of the resonant LC filter by significantly attenuating the current induced on the wire before it reaches the resonant LC filter. The resonant LC filter may also be positioned distal to the end of the non-resonant filters with the non-resonant filters proximate the electrode.