US 4,923,459 A · Stereotactics apparatus

Abstract

A stereotactics apparatus comprises a frame fixed on a head of a patient and a marker member fixed on the frame. The frame has a frame coordinate system within which the head and the marker member are located. The marker member is tomographically imaged together with the head by a tomographic imaging apparatus (e.g. MRI apparatus), and is displayed as marker image together with the tomographic image of the head. The coordinate system is reconstructed on the basis of the displayed marker image, so that coordinates of the surgical target are calculated on the basis of the reconstructed coordinate system. The marker member is located on an imaginary curved surface having a concave shape toward the head and located on the frame. Thus, the marker member is located at angular position such that all portions of the marker member are equidistantly away from a center of magnetic field. Therefore the marker member can be located comparatively near the center. Since the nonuniformity ofthe magnetic field intensity is minimized at a position closer to the center, the marker image distortion is suppressed, thus reducing the positional deviation of the marker image. Therefore, the coordinate system can be accurately reconstructed on the image, and hence the coordinates of the surgical target can be accurately calculated.

Claims15

Dependent claims

A stereotactics apparatus which is adapted to utilize tomographic imaging means for photographing a predetermined portion of a patient to display a tomographic image of the predetermined portion so as to designate a surgical target of the predetermined portion on the basis of the tomographic image, comprising:

frame means having a frame coordinate system and fixed in the predetermined portion such that the predetermined portion is located within the frame coordinate system;
and
means for calculating the coordinates of the surgical target in the frame coordinate system, said calculating means being provided with a marker member, said marker member being fixed on said frame means so that said marker member is adjacent to the predetermined portion and located within the frame coordinate system, said marker member being adapted to be tomographically imaged together with said predetermined portion by said imaging means and being adapted to be displayed as marker image together with the tomographic image of the predetermined portion, whereby the frame coordinate system is reconstructed on the basis of the displayed marker image, so that the tomographic image of the predetermined portion is located within the reconstructed frame coordinate system and coordinates of the surgical target are calculated on the basis of the reconstructed frame coordinate system,
wherein said frame means includes a curved surface having a concave shape toward the predetermined portion, and said marker member is spirally extending along the curved surface.

1 more element

A stereotactics apparatus which obtains a tomographic image of a predetermined portion of a patient to designate a surgical target on the basis of the tomographic image, comprising:

frame means having a frame coordinate system and fixed to the predetermined portion so that the predetermined portion is located within the frame coordinate system;
a marker member fixed to said frame means so that said marker member is adjacent to said predetermined portion and located within the frame coordinate system, and which is displayed as marker images together with the tomographic image of the predetermined portion;
tomographic imaging means for tomographically imaging said marker member together with the predetermined portion and outputting an image signal;
and
means for displaying the marker image together with the tomographic image of the predetermined portion on the basis of the image signal, whereby the frame coordinate system is reconstructed on the basis of the displayed marker image, so that the tomographic image of the predetermined portion is located within the frame coordinate system, and coordinates of the surgical target are calculated on the basis of the reconstructed frame coordinate system,
wherein said frame means includes a curved surface having a concave shape toward the predetermined portion, and said marker member is spirally extending along the curved surface.

3 more elements

Dependencies are inferred from the claim text.

Stereotactics apparatus

Life of this patent

Stereotactics apparatus

Life of this patent

Abstract

Claims15