Method and instrument for surgical navigation

Abstract

An operating microscope including an optical unit for forming an image of an object plane in oculars of the microscope, an optoelectronic image receiver coupled to the microscope and optics to form images, of objects placed in a region between a front objective of the microscope and an object plane of the microscope, on the optoelectronic image receiver. The microscope has a magnification factor of the optics to form images, and a system to detect optical markings forming a markings pattern placed on a surgical instrument or an object placed in the region between the front objective of the microscope and the object plane of the microscope. The system calculates a geometrical position and orientation of the markings pattern in relation to the optoelectronic image receiver, relative to the microscope.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part application of U.S. Ser. No. 10 / 516,297, filed Dec. 19, 2005. U.S. Ser. No. 10 / 516,297 is a national stage application of PCT / EP03 / 06130, filed Jun. 11, 2003, and claims priority to DE 102 49 025.2, filed Oct. 21, 2002, and DE 102 26 361.2, filed Jun. 13, 2002. The entire content of each is incorporated herein by reference.BACKGROUND[0002]1. Field of Invention[0003]This disclosure relates to optimizing identification of a current position in surgical navigation, especially neuronavigation, in surgery with an operating microscope and at least one optoelectronic image receiver, which may also be integral or connectable to the microscope and a computer system.[0004]2. Discussion of the Related Art[0005]Neuronavigation deals with the planning, but also with the performance of trajectories for surgical intervention at the human brain, the spine and the like. To this end, tomographies of the patient ar...

AI Technical Summary

Benefits of technology

[0021]Accordingly, the basic idea of the invention is to improve the position-identifying time of a navigational system by including the images from or parallel to the observation channels of the operating microscope in the actual image analysis of said system and to achieve additional advantageous effects, especially under the aspect of improving the exactness of the positional determination.

, especially under the aspect of improving the exactness of the positional determination.

Problems solved by technology

Optical systems have the disadvantage that there is the danger of the camera being covered by the operating staff.

Magnetic systems fail to operate once objects made of soft iron are in the proximity thereof, which upset or distort the magnetic fields.

The disadvantage in said last-mentioned systems resides in that the carrier systems used therefore required a reinforcement so as to ensure a sufficient exactness, which renders them disproportionately heavy and expensive.

If the markings are covered, the functional capability is negatively influenced and errors in the data acquisition occur.

According to experience the so-called position-identifying times of optical, but also of magnetic navigation systems are about ⅔. In addition, the large distance between the markings of the known optical instruments and the camera pair causes large measuring inaccuracies in the optical measurement, and relatively large-volume markings are required.

Another problem with current neurosurgical navigational systems resides in the motion of the brain tissue after the skullcap was opened and during the operation.

This fact called brain shift results in that the geometry of the tissue during the operation no longer unlimitedly corresponds to the geometry of the tissue during the preoperative diagnostic method.

This leads to errors, for example, in the aforementioned position indication of a pointer instrument relative to the tissue structures in a preoperative diagnostic MR- or CT-image.

Given the stress, which in a neurosurgical operation is high enough anyhow, this constitutes a disadvantage, however.

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