Optical calibration method of ultrasonic probe

Abstract

The invention discloses an optical calibration method of an ultrasonic probe. The optical calibration method of the ultrasonic probe includes the following steps: (1) pasting character identification points on the ultrasonic probe, (2) fixing a three-dimensional calibration template and optical positioning equipment, (3) and holding the ultrasonic probe in hand to scan the three-dimensional calibration template, obtaining a space gesture of the ultrasonic probe by using the optical positioning equipment at the time of every time gathering ultrasound images to obtain original data and calibrating the ultrasonic probe by using a least square method. Compared with a traditional electromagnetic calibration method, the optical calibration method of the ultrasonic probe has the advantages that calibration results are more accurate, due to the fact that in the process of calculation only an unknown number exists (an unknown transformation matrix), complexity of calibration calculation is reduced, the optical calibration method of the ultrasonic probe can be applied into various types of ultrasound probes, equipment is simple and convenient and range of application is wide. The optical positioning equipment is used for obtaining the gesture of the ultrasonic probe, influence of power cords is not needed to consider and calibration range is wider, and the optical positioning equipment does not have a problem of electromagnetic compatibility in a surgical navigation environment.

Description

technical field [0001] The invention relates to an optical calibration method, in particular to an optical calibration method of an ultrasonic probe. Background technique [0002] Existing manual three-dimensional ultrasonic image calibration method based on the magnetic locator: fix an electromagnetic receiver on the ultrasonic probe, utilize the electromagnetic locator to obtain the spatial information of the receiver relative to the transmitter, and establish the ultrasonic image coordinate system I, receiver Coordinate system R, emitter coordinate system T, template coordinate system C four coordinate systems, the calibration formula is P(C)= C T T · T T R · R T I · P(I), where T T R Represents the transformation matrix from the electromagnetic receiver to the transmitter, the ultrasonic image coordinates P(I) of known spatial points, the corresponding template coordinates P(C) and the measured T T R , using the least squares method to obtain the spatial mapping...

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Problems solved by technology

[0004] (1) The designed N-shaped calibration template is only a two-dimensional calibration template in space, and the obtained calibration template coordinates lack the third-dimensional spatial information;

[0005] (2) Calibration formula P(C)= C T T * T T R * R T I *The unknowns in P(I) are C T T and R T I Two, the calculation is more complicated, and multiple calibration images need to be collected;

[0006] (3) By default, the receiver coordinate system is used instead of the ultrasonic probe coordinate system, and there may be transformation errors;

[0007] (4) It is necessary to fix the electromagnetic receiver on the ultrasonic probe, the movement is limited, and different specifications of electromagnetic positioners need to be equipped for different types of ultrasonic probes, which makes the equipment complicated and the adaptability is not high;

[0008] (5) Electromagnetic positioning equipment has electromagnetic compatibility problems in surgical navigation applications

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