Technologies


Method and Apparatus for Segmenting Small Structures in Images

Reference#: P01374


What is needed is a segmentation method and apparatus without statistical models, local statistics, or thresholds to be selected manually, and with significantly lower computational complexity compared to the multi-tolerance and active contours methods, for enhanced speed.

In particular, what is needed is a method and apparatus to segment pixels in an image, such as a mammogram, containing a plurality of extra dark or extra bright objects just a few pixels in extent, that gives edges similar to those selected by an expert, but does so with fewer computations and with fewer manually adjustable parameters than conventional segmentation methods and equipment.

Therefore it is an object of the present invention to provide segmentation for small features in multidimensional data which defines small feature edges that correspond closely to those selected by an analyst but does so with less complexity than the above known methods.

The invention further pertains to a system for performing the method described above, comprising: a radiological image generating device for generating an image of a target anatomy of a patient to be operated on for determining a needle trajectory to be followed through the patient, the image generating device being positionable to generate an image of the target anatomy from a plurality of directions; and a needle insertion mechanism disposed adjacent the image generating device and having a needle adapted to be inserted into the patient and to be locked in a direction of the needle trajectory.

According to one aspect of the invention, the needle insertion mechanism comprises both a needle and a needle driver, which includes: a first rotational component having a first contact face and being adapted to rotate about a rotational axis; and a second rotational component coaxial with the first rotational component and having a second contact face facing the first contact face and spaced therefrom, the needle being spaced from the rotational axis and further being pressed between the contact faces thereby applying an axial force to each of the contact faces directed parallel to the rotational axis, the axial force effecting a frictional engagement of the needle with the contact faces, the second rotational component further being adapted to rotate about the rotational axis such that, when the rotational components rotate about the rotational axis, the frictional engagement of the needle with the contact faces effects a translational motion of the needle.

The invention further pertains to a motion transmission mechanism comprising both an output shaft and an output shaft driver, which includes: a first rotational component having a first contact face and being adapted to rotate about a rotational axis; and a second rotational component coaxial with the first rotational component and having a second contact face facing the first contact face and spaced therefrom, the output shaft being spaced from the rotational axis and further being pressed between the contact faces thereby applying an axial force to each of the contact faces directed parallel to the rotational axis, the axial force effecting a frictional engagement of the output shaft with the contact faces, the second rotational component further being adapted to rotate about the rotational axis such that, when the rotational components rotate about the rotational axis, the frictional engagement of the output shaft with the contact faces effects a translational motion of the output shaft.

The simplicity of the method and system according to the present invention is achieved by combining the proven radiological image guidance procedures and devices of the prior art with a simple and cost-effective needle injection device which exhibits an extremely low radiological profile. The needle injection device further provides actuated needle motion in conjunction with a mechanical manipulator designed to be used in existing operating rooms without the necessity of additional computers or personnel.

Accordingly, the method and device of the present invention mimic and improve upon the surgeon's standard technique. The key advantages of the present invention are that it involves the use of a proven radiological needle alignment procedure, improves accuracy in comparison with purely manual needle positioning techniques, and enables lateral fluoroscopic monitoring of the needle without necessitating computer-based vision and robotic systems. The present invention results in a shortening of procedure durations, improves upon patient safety, ensures and improves upon equipment sterility, and reduces the radiation exposure of surgeons.

A further advantage of the method according to the invention is that it does not require image correction and calibration. By superimposing the needle, the insertion site and the target, any image distortions are identical, and therefore, cancel each other. Moreover, the method of the present invention requires direct observation by only the surgeon involved, and hence does not necessitate image-processing that is computer based, thereby significantly reducing operative time and expense.

Patent Status: U.S. patent(s) 7106893 issued.

CONTACT:
Mr. J. E. Dietz
Phone: (443) 778-8782
ott-techmanager5@jhuapl.edu

Additional References:

Patent Drawing