Abstract: A method of delivering a substance to targeted tissue comprising the steps of: delivering a plurality of magnetically responsive particles which are carrying the substance and have a hydrophobic coating into the patient's vasculature upstream of the targeted tissue; and applying a magnetic gradient in the vicinity of the targeted tissue to draw the magnetically responsive particles against the wall of the patient's vasculature in the vicinity of the targeted tissue, to allow the substance on the magnetic particles to migrate through the wall of the patent's vasculature to targeted tissue.

Abstract: A method of turning a medical device, having a magnetically responsive element associated with its distal end, at an operating point within an operating region inside a patient's body from an initial direction to a desired final direction, through the movement of at least one external source magnet. The at least one external source magnet is moved in such a way as to change the direction of the distal end of the magnetic medical device from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.

Abstract: A method of localizing a medical device inside a patient's body, the method comprising: transmitting ac magnetic signals between a plurality of points of known location outside of the patient's body and a plurality of points on the medical device inside the patient's body, the signals transmitted between at least some of the points comprising at least two different frequencies; and receiving the transmitted ac magnetic signals and processing the received signals to determine the position of the points on the medical device, and thus the location of the medical device, this processing including correcting for the affects of metal in the vicinity by using the transmitted and received signals at different frequencies. In an alternate embodiment, a reference device is provided inside the patients' body, and the medical device is localized relative to the reference catheter.

Abstract: An apparatus and method for locating a magnetic implant in a surgical application using the field of a source magnet for the implant guiding field. The source magnet is an electromagnet having a separate calibrated magnetic field component in addition to the guiding field, so that both the magnitude and orientation of the magnetic field as a function of position around the magnet are known. A magnetic implant is provided with a sensor, such as a three-axis Hall effect sensor, to provide an indication of the magnitude and orientation of an applied magnetic field when the implant is surgically implanted in a patient. After implantation, the source magnet is energized with a current having a modulated component. The modulated component is received and filtered from the signal received from the Hall effect sensor in the implant, and provided to a processor that computes the location of the implant.

Abstract: A method of turning a medical device with the assistance of an externally applied magnetic field, in a direction with a component in a plane perpendicular to the direction of the externally applied magnetic field. The method includes applying first torque to the distal end of the medical device by creating magnetic moment at the distal end of the medical device, and applying a second torque to the distal end of the medical device. The second torque may be created by creating a second magnetic moment at the distal end of the device spaced from the first, by using an electrostrictive device, by using a stylette inserted into the device, by using a fluid-driven shaped tube, or otherwise.

Abstract: A method of turning a medical device, having a magnetically responsive element associated with its distal end, at an operating point within an operating region inside a patient's body from an initial direction to a desired final direction, through the movement of at least one external source magnet. The at least one external source magnet is moved in such a way as to change the direction of the distal end of the magnetic medical device from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.

Abstract: An embolic material comprising a polymerizable hydrophobic suspension of coated magnetically responsive particles (e.g. magnetite Fe3O4) suspended in a solvent monomer, a bulking agent, a radiopaque monomer, and an accelerant, and an initiator. The coated magnetically responsive particles preferably have a diameter of between about 20 and about 40 nm, and a magnetically responsive core with a diameter of between about 2 and about 20 nm.

Abstract: A method of turning a medical device, having a magnetically responsive element associated with its distal end, at an operating point within an operating region inside a patient's body from an initial direction to a desired final direction, through the movement of at least one external source magnet. The at least one external source magnet is moved in such a way as to change the direction of the distal end of the magnetic medical device from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.

Abstract: A method of delivering a substance to targeted tissue comprising the steps of: delivering a plurality of magnetically responsive particles which are carrying the substance and have a hydrophobic coating into the patient's vasculature upstream of the targeted tissue; and applying a magnetic gradient in the vicinity of the targeted tissue to draw the magnetically responsive particles against the wall of the patient's vasculature in the vicinity of the targeted tissue, to allow the substance on the magnetic particles to migrate through the wall of the patent's vasculature to targeted tissue.

Abstract: A system for magnetically assisted surgery includes a magnetic support structure, a patient support structure and a magnet having at least four poles attached to the magnetic support structure so that the magnet provides a near-field magnetic field in an operating region of a patient supported by the patient support structure. The magnet is moveable so that the direction of the magnetic field lines in the operating region is adjustable. The magnet may include a pair of essentially semicircular half-segments permanently magnetized and joined in an extremely stable disk configuration. The magnetic field and gradient field provided by the magnet is such that movement of the disk in one plane combined with rotation of the disk is sufficient to orient the magnetic field during surgical use, thereby reducing interference to medical imaging devices needed during surgery.

Abstract: A method of turning a medical device, having a magnetically responsive element associated with its distal end, at an operating point within an operating region inside a patient's body from an initial direction to a desired final direction, through the movement of at least one external source magnet. The at least one external source magnet is moved in such a way as to change the direction of the distal end of the magnetic medical device from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.

Abstract: A method of navigating a magnet-tipped distal end of an elongate medical device through the body includes providing an image display of the part of the body through which the medical device is being navigated and using the display to input the desired path of the medical device by identifying points on the desired path on the display. The magnetic field needed to orient the end of the medical device in the direction of the desired path as indicated on the display is then determined. In one embodiment where only points on the desired path are identified, the field direction is the direction indicated by the points on the desired path.

Abstract: A method of turning a medical device, having a magnetically responsive element associated with its distal end, at an operating point within an operating region inside a patient's body from an initial direction to a desired final direction, through the movement of at least one external source magnet. The at least one external source magnet is moved in such a way as to change the direction of the distal end of the magnetic medical device from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.

Abstract: A system for magnetically assisted surgery includes a magnetic support structure, a patient support structure and a magnet having at least four poles attached to the magnetic support structure so that the magnet provides a near-field magnetic field in an operating region of a patient supported by the patient support structure. The magnet is moveable so that the direction of the magnetic field lines in the operating region is adjustable. The magnet may include a pair of essentially semicircular half-segments permanently magnetized and joined in an extremely stable disk configuration. The magnetic field and gradient field provided by the magnet is such that movement of the disk in one plane combined with rotation of the disk is sufficient to orient the magnetic field during surgical use, thereby reducing interference to medical imaging devices needed during surgery.

Abstract: An apparatus and method for locating a magnetic implant in a surgical application using the field of a source magnet for the implant guiding field. The source magnet is an electromagnet having a separate calibrated magnetic field component in addition to the guiding field, so that both the magnitude and orientation of the magnetic field as a function of position around the magnet are known. A magnetic implant is provided with a sensor, such as a three-axis Hall effect sensor, to provide an indication of the magnitude and orientation of an applied magnetic field when the implant is surgically implanted in a patient. After implantation, the source magnet is energized with a current having a modulated component.

Abstract: A method of localizing a medical device inside a patient's body, the method comprising: transmitting ac magnetic signals between a plurality of points of known location outside of the patient's body and a plurality of points on the medical device inside the patient's body, the signals transmitted between at least some of the points comprising at least two different frequencies; and receiving the transmitted ac magnetic signals and processing the received signals to determine the position of the points on the medical device, and thus the location of the medical device, this processing including correcting for the affects of metal in the vicinity by using the transmitted and received signals at different frequencies. In an alternate embodiment, a reference device is provided inside the patients' body, and the medical device is localized relative to the reference catheter.

Abstract: The movement of a catheter through a medium, which may be living tissue such as a human brain, is controlled by mechanically pushing a flexible catheter having a magnetic tip through the medium and applying a magnetic field having a magnitude and a direction that guides the mechanically-pushed catheter tip stepwise along a desired path. The magnetic field is controlled in a Magnetic Stereotaxis System by a processor using an adaptation of a PID (proportional, integral, and derivative) feedback method. The magnetic fields are applied by superconducting coils, and the currents applied through the coils are selected to minimize a current metric.

Abstract: A method of applying an elongate magnetic element to the surface of an internal body structure includes applying a magnetic field to the elongate magnetic element to orient the elongate magnetic element in a selected orientation; and applying a magnetic gradient to the elongate magnetic element to draw the elongate magnetic element against the surface of the body structure.

Abstract: A device and a method for guiding or applying force to a magnetic implant within the body of a patient. The device includes a bed for support of the patient, a set of separately energizable electromagnets or separately controllable permanent magnets so arranged to produce magnetic fields of varying orientations in a treatment region of the patient, and a processor that controls the currents in the electromagnets, or shutters on the permanent magnets to produce a selected magnetic field and/or gradient for guiding or moving the implant. The magnets are configured to allow a medical imaging device to be used to provide a real-time display of an operating procedure in which magnetic guidance is used.

Abstract: A method of navigating a magnet-tipped distal end of an elongate medical device through the body includes providing an image display of the part of the body through which the medical device is being navigated and using the display to input the desired path of the medical device by identifying points on the desired path on the display. The magnetic field needed to orient the end of the medical device in the direction of the desired path as indicated on the display is then determined. In one embodiment where only points on the desired path are identified, the field direction is the direction indicated by the points on the desired path.