Registration probe and system for measuring cartilage thickness

Abstract

A registration probe is provided, including: a target seat provided with a target, a fixed probe, a circuit module, and a movable probe that can move relative to the fixed probe, and the circuit module can adjust the motion generated based on the relative movement between the probes. electrical signal processing. Also provided is a navigation aid instrument system having the registration probe, and a method for measuring cartilage thickness using the system. When the end of the fixed probe contacts the bone surface, the end of the moving probe is aligned with the end of the fixed probe. When the fixed probe starts to puncture the cartilage layer on the bone surface, the moving probe starts to move in the opposite direction, and the electric signal generated by the moving grid and the fixed grid is used to convert the signal into displacement by the circuit module. When the end of the fixed probe touches the hard surface of the bone, the navigation tracker determines the spatial coordinates of the end of the fixed probe. This coordinate can be accurately registered with the bone surface coordinates in the CT image. At this time, the obtained moving probe The amount of displacement is the thickness of the cartilage on the bone surface.

Description

technical field [0001] The invention relates to a registration probe, a system with the registration probe, in particular for measuring cartilage thickness, and a method for measuring cartilage thickness. Background technique [0002] In the medical field, image navigation is often used to guide doctors to perform operations. As a navigation aid, a registration probe is known, which is used in surgical navigation to accurately import the three-dimensional coordinate points measured in the real space into the virtual three-dimensional coordinates where the navigation tracker is located. [0003] On the surface of the registration probe, there are generally several targets (cross targets, reflective balls, reflective disks, etc.), which are reflected back to the camera in the navigator by reflecting the light beam (or external light beam, such as natural light) emitted by the navigation tracker. In the module, after specific algorithm calculation, the navigation tracker can k...

AI Technical Summary

Problems solved by technology

[0008] The first method can obtain the coordinates of the feature points on the surface of the dense bone, so that the real bone can be well overlapped with the CT image, but it cannot obtain information such as the thickness of the cartilage layer, so that it can be used to judge the bone structure, such as the thickness of the cartilage in the knee joint. , it will cause information loss, so it is impossible to accurately judge the selection of the prosthesis model

Can only rely on experience to complete surgical planning, resulting in poor surgical results

[0009] The second method can obtain the coordinates of the feature points on the cartilage surface, but in the CT image, because there is no cartilage information, the corresponding feature points cannot be found

Therefore, in the process of overlapping the real bone and the CT image, it is necessary to use an algorithm for surface fitting. This method will introduce errors when the two overlap, resulting in errors in the coordinates of the real bones in the virtual space, which will eventually affect the precise planning and lead to Ineffective surgery

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