Robotic Patient Surface Sampling for 3D Image Registration
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Solution Overview
Problem
The current medical registration process of matching a 3D image with a patient's surface is cumbersome and time-consuming, often resulting in sub-optimal sampling of points due to inefficiencies in acquiring and updating the registration, particularly in terms of accuracy and reliability.
Innovation Solution
A method utilizing a robot equipped with a surface point sampling device to iteratively sample spatial locations on a patient's surface, updating the registration based on sampled points, and optimizing the sampling process through predetermined exit conditions such as time, total points, accuracy, or registration confidence, allowing for improved point selection and trajectory planning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual surface point sampling is used for patient registration, then the registration process can be completed, but the procedure is cumbersome and time-consuming with sub-optimal sampling quality
Solution Approach 1:
The patent replaces manual mechanical sampling with an automated robotic arm system that carries a surface point sampling device. The robot automatically positions and samples surface points based on trajectory planning, eliminating manual operation while maintaining or improving sampling quality through precise control and optimization algorithms.
Solution Approach 2:
The patent implements iterative sampling where the sampling process is repeated multiple times with updating registration results. Between iterations, the system refines parameters such as sampling density, trajectory points, and registration transformations to progressively improve both speed and accuracy of the registration process.
2Measurement precision
If more surface points are sampled to improve registration accuracy, then the registration quality improves, but the time required for the procedure increases
Solution Approach 1:
The patent uses iterative sampling where not all surface points are sampled to full precision in every iteration. Instead, the system performs multiple passes with updating registration, sampling strategically selected points in each iteration to achieve sufficient accuracy without the time cost of exhaustive sampling.
Solution Approach 2:
The system performs preliminary registration using a subset of surface points or coarse sampling first, then uses this initial registration to guide subsequent more precise sampling. This preliminary action reduces the overall time by avoiding the need to sample all points to full precision from the start.
3Productivity
If a robot is used to automate surface point sampling, then the efficiency and accuracy of registration is improved, but the device complexity increases
Solution Approach 1:
The robotic arm system is designed to perform multiple functions: it carries the surface point sampling device, executes trajectory planning, and integrates with the registration software. This multi-functionality justifies the increased complexity by consolidating sampling, positioning, and control into a single automated platform.
Solution Approach 2:
The patent introduces a computer as an intermediary that coordinates between the robot control system and the registration software. The computer manages trajectory planning, processes sampling data, and updates registration results, acting as a mediator that simplifies the overall system architecture despite the added robotic component.
4Measurement precision
If iterative sampling and registration updating is performed, then the registration precision is enhanced, but the computational time per iteration increases
Solution Approach 1:
In each iteration, the system samples only a subset of surface points rather than all points, performing partial sampling that is sufficient to improve registration precision without requiring exhaustive computation. The iterative process accumulates these partial results to achieve high overall precision.
Solution Approach 2:
The system performs preliminary registration calculations using available data before each iterative sampling phase. This preliminary action provides an initial registration state that reduces the computational burden of subsequent iterations, as later iterations only need to refine rather than compute from scratch.
Data Source
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AI summary
A method of operating a medical registration system, the medical registration system comprising a robot which carries a surface point sampling device and comprising a computer connected to the robot, to obtain a registration of a 3D image of a patient with the patient (P) by: a) acquiring the 3D image of the patient; b) acquiring an initial registration of the 3D image with the patient as the registration; c) instructing the robot to sample the spatial locations of N different points on the surface of the patient using the surface point sampling device, wherein N is a positive integer; d) updating the registration based on the spatial locations of the N sampled points; and e) repeating steps c) and d) until a predetermined exit condition is fulfilled.