Rotating Magnet Orientation Tracking for Surgical Navigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inertial sensors used in orthopedic surgery primarily provide orientational information rather than positional information, posing challenges in navigating surgical tools accurately without methods to create bone references and tools effectively.
Innovation Solution
A computer-assisted surgery system utilizing a rotating magnet and magnetometer to generate and track orientation-based information, allowing for precise navigation of surgical tools relative to bones by creating a magnetic field plane and using a processing unit to interpret signals from the magnetometer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inertial sensors are used for tracking surgical tools, then orientational information can be obtained, but positional information is not provided
Solution Approach 1:
A magnetic field is introduced as an intermediary between the inertial sensors and the tracking system. The magnetic field serves as a mediator that enables the magnetometer to detect orientation relative to a magnetic source, compensating for the inability of inertial sensors to provide absolute positional information. This intermediary field allows the system to establish a reference frame for accurate tracking.
2Measurement precision
If a rotating magnet and magnetometer system is implemented, then orientation tracking precision is improved, but device complexity increases
Solution Approach 1:
The rotating magnet system serves multiple functions: it generates the magnetic field for orientation detection, provides a reference frame for the magnetometer, and enables calculation of surgical tool orientation relative to bone. By making the magnetic field generator multi-functional, the system achieves high precision without proportionally increasing complexity.
Solution Approach 2:
The system uses the rotating magnet's own magnetic field to serve the detection needs of the magnetometer. The magnetic field generated by the rotating magnet automatically provides the reference information needed for orientation calculation, eliminating the need for separate reference markers or additional complex infrastructure.
3Ease of manufacture
If inertial sensors operate relative to gravity, then simple orientation measurement is achieved, but absolute positional reference is lost
Solution Approach 1:
The magnetic field acts as an intermediary reference system that provides absolute positional information without complicating the sensor operation. While inertial sensors continue to operate simply relative to gravity, the magnetic field intermediary enables the system to establish an absolute reference frame for determining the surgical tool's position and orientation relative to the bone.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate orientation tracking of surgical tools, providing data on angles like anteversion and abduction/adduction, enhancing precision in orthopedic surgeries by overcoming the limitations of inertial sensors in providing positional information.
Implementation Method 1
a rotating magnet creating a magnetic field plane
Implementation Method 2
a magnetometer on the other of the instrument and the reference device, the magnetometer producing signals as a function of at least its orientation relative to the magnetic field plane
Data Source
AI summary
A computer-assisted surgery system comprises instruments adapted to be used to perform tasks related to surgery. A reference device is in a fixed relation to a bone. A rotating magnet creates a magnetic field plane, the rotating magnet being connected to one of the instrument and the reference device. A magnetometer on the other of the instrument and the reference device produces signals as a function of at least its orientation relative to the magnetic field plane. A processing unit tracks said orientation of the instrument relative to the bone using said signals from the magnetometer subjected to the magnetic field plane.