A calibration device for real-time tracking of the position of free bone fragments

Abstract

The invention relates to a calibration method for real-time tracking of the free bone block position. The calibration method is characterized by comprising the steps that S1, a three-dimensional modelof a target skeleton is established; S2, the osteotomy path and the ideal reposition position of a free bone block are designed on the three-dimensional model, and a preoperative planning scheme is introduced; S3, tracking reference frames are arranged on a skeleton entity and a truncated bone block correspondingly; S4, mark points are selected on the three-dimensional model and the skeleton entity correspondingly, an initial registration matrix and an initial free bone block calibration matrix are obtained, and the mark points on the three-dimensional model and the skeleton entity correspondin a one-to-one mode in position; and S5, a positioning probe slowly slides on the surface of the skeleton entity to pick up a series of point clouds, surface registration is conducted, a precision registration matrix and an accurate free bone block calibration matrix are obtained, and calibration of the free bone block is completed. Compared with the prior art, through the calibration method ofpoint and surface combination, the calibration accuracy can be effectively improved, and injury to a patient is reduced.

Description

technical field [0001] The invention relates to a calibration technology, in particular to a calibration device for real-time tracking of the position of a free bone block. Background technique [0002] In clinical repair and reconstruction surgery, the precise positioning of free bone fragments is crucial to the success of surgery. For example, in the diagnosis and treatment of dentofacial deformities, orthognathic surgery involves changes in the three maxillofacial structures (jawbone, facial soft tissue, and the occlusal relationship of the dentition), and small deviations in the restoration of free bone blocks may seriously affect the appearance. Bring lifelong pain to patients. Although the traditional use of osteotomy guides can assist doctors in determining the three-dimensional spatial relationship of the patient's maxillofacial teeth, the design and fabrication process is cumbersome, consuming a lot of time and energy for medical staff, and it is difficult to accur...

AI Technical Summary

Problems solved by technology

However, in actual surgery, doctors cannot pre-design accurate reference points on free bone fragments. The registration method using external landmarks requires the use of invasive tools to pre-implant titanium screws on the patient's body or use a stereotaxic frame. The registration accuracy of the method is relatively high, but it will bring physical trauma and pain to the patient, especially the orthopedic surgery cannot strip the patient's anatomical tissue in advance and implant titanium screws, so it is not accepted by the patient

If the patient's own anatomical landmarks are used for registration, there will be deviations when selecting corresponding points between the virtual image and the patient, resulting in unsatisfactory registration accuracy and unable to meet clinical accuracy requirements

Clinicians are still faced with the challenging problem of how to accurately position and install free bone fragments during surgery according to the preoperatively planned position

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