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AssigneesUniversity of Virginia Patent Foundation, Stereotaxis, Inc.
InventorsRogers C. Ritter, Michael A. Lawson, Robert G. McNeil
Estimating the term…
A control method permits the operation of multiple superconducting magnetic coils so as to move a magnetic object to precisely specified locations within the body under command of a physician-operator observing the motion with live fluoroscopic imaging fused with more detailed preoperative imaging of some other kind. A computer contains the preoperative images and the fluoroscopic images, as well as the means to effect changes in the coil currents so as to accomplish the desired magnetic object motion and positioning. The control method operates the coils in pairs on opposite sides of the body in a manner to minimize the necessary current changes, thus avoiding the quenching of the superconducting coils. Combinations of these pairs can execute motion of the magnetic object in any direction in an impulsive manner and with high precision. The method should function well and provide advantages with coils which are not superconducting as well. The method overcomes the redundance present in the limited constraints given by a simple movement vector by the physician-operator.
A method of operating plural sets of superconducting coils, comprising providing strong force impulses and accurate motion steps of a small magnetic object in a combined field of the sets of coils, and minimizing a risk of quenching the coils, including the following steps:
A method of operating plural pairs of coils, in a manner to avoid lack of specificity of specifying only the force magnitude and direction on a magnetic object, comprising:
A magnetic stereotaxis system comprising a pair of spaced coils having a first, main, pulling coil and a second, subsidiary, pushing coil mounted at a spaced position from the first coil for establishing combined magnetic fields and gradients between the first and second coils, a magnetic object positioned in a media between the coils, a current in the first coil for producing a sub-threshold force for aligning the magnetic object in the media, which sub-threshold force is below a threshold force necessary to move the magnetic object through the media, a current supplied to the second coil for producing a boost force in combination with the sub-threshold force of the first coil as a combined force for exceeding the threshold force and producing movement of the magnetic object in the media, means for reversing the current in the second coil for providing a halt force for reducing the combined force to below the threshold force and for halting movement of the magnetic object in the media.
The method of controlling movement of a magnetic element in a media, comprising providing a first pair of spaced coils having a first main pulling coil and a second subsidiary pushing coil spaced from the first coil, providing a current in the first coil for providing from the first coil a sub-threshold force for holding the magnetic object in the media without moving the magnetic object through the media, providing a boost current in the second subsidiary coil for producing a boost pushing force additive with the sub-threshold force from the first coil for providing a total force in excess of the threshold force and moving the magnetic object in the media, providing a halt current in the subsidiary coil for producing a pulling halt force from the secondary coil which is subtractive from the pulling sub-threshold force of the first coil for stopping the magnetic object in the media.
A method of operating a pair of coils to move a magnetic object in soft body tissue, the method comprising the steps of:
A method of moving a magnetic object in a body part to a specific location using a set of mutually perpendicular coil pairs controlled by a controller, the method comprising the steps of:
The method of controlling a movement of a magnetic object in a body, comprising viewing present magnetic object position in a body on a computer screen, inputting a desired vector position change for the object and showing the desired change on the screen as a red arrow, calculating magnetic forces on the magnetic object needed to move the object as indicated by the red arrow, calculating movement of the object in the body by the application of the magnetic forces and displaying the calculated movement on the screen as a green arrow, moving the red arrow on the screen and recalculating the forces and movement of the magnetic object for moving the green arrow to the original position of the red arrow and applying the recalculated forces to the object.
Dependencies are inferred from the claim text.