Bone Reconstruction and Orthopedic Implants

Abstract

A surgical navigation module comprising: (a) a microcomputer; (b) a tri-axial accelerometer; (c) a tri-axial gyroscope; (d) at least three tri-axial magnetometers; (e) a communication module; (f) an ultrawide band transceiver; and, (g) at least four ultrawide band antennas.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 62 / 022,899, entitled, “CRANIUM AND POSTCRANIAL BONE AND SOFT TISSUE RECONSTRUCTION,” filed Jul. 10, 2014, the disclosure of each of which is incorporated herein by reference.RELATED ARTField of the Invention[0002]The present disclosure is directed to various aspects of orthopedics including bone and tissue reconstruction, patient-specific and mass customized orthopedic implants, gender and ethnic specific orthopedic implants, cutting guides, trauma plates, bone graft cutting and placement guides, patient-specific instruments, utilization of inertial measurement units for anatomical tracking for kinematics and pathology, and utilization of inertial measurement units for navigation during orthopedic surgical procedures.INTRODUCTION TO THE INVENTION[0003]The present disclosure includes a surgical navigation system using a self-reference hybrid navigati...

AI Technical Summary

Benefits of technology

The present patent is about a surgical navigation system that combines the use of ultra wide band (UWB) and inertial measurement units (IMU) to provide precise tracking and surgical navigation. The system addresses the limitations of current navigation systems such as optical, EM, and inertial systems, and solves issues such as line-of-sight requirements, accuracy, and orientation tracking. The UWB system uses a sequential Monte Carlo algorithm to calculate changes in position, while the IMU system uses a combination of UWB and IMU sensors to track the movement of the surgical tool. The system also addresses the challenge of calibration and installation of multiple anchors and includes a hybrid tracking system that integrates the UWB and IMU systems to achieve high accuracy surgical navigation.

Problems solved by technology

The primary challenge with optical surgical navigation systems is the line-of-sight (LOS) requirement between the camera and the tracking modules, which is often obstructed by the surgeons or the surgical technicians during surgery.

The patient registration error for the camera can also introduce substantial error in the system.

The EM navigation does not suffer from line-of-sight requirement, however, the accuracy of the system is reduced with metallic objects in the vicinity of the probe.

This is a common problem in many surgeries when multiple metallic equipment parts are utilized, such as metal retractors.

Inertial navigation systems are not accurate for translation navigation without external observation inputs, such as a global positioning system (GPS) or an optical navigation system to correct for arithmetic drifting.

Inertial navigation is also limited to orientation navigation, and can be inaccurate from ferromagnetic, martensitic material, or permanent magnet distortion.

However, the tracking accuracy of a TOA system is in the range of meters, which is not suitable for high accuracy surgical applications.

However, the implementation of a TDOA system is substantially more challenging than TOA system.

But to date, no TDOA system is reliable for surgical navigation.

Specifically, current UWB systems do not have optimized antenna for their intended applications, and do not account for orientation dependencies caused by antenna polarization.

Yet most UWB localization systems do not account for harsh indoor environments having numerous multipaths and the potential for non-line-of-sight conditions, both of which are common in surgical environments (e.g., operating rooms and surgical suites).

Moreover, the deployment of current UWB localization methods also suffer from limitations such as strict anchor configurations and installation, tedious calibration procedures, and inaccuracy from incoherent clock between anchors.

For the UWB system, calibration and installation of multiple anchors remains a primary challenge in achieving high accuracy.

Incoherent clock synchronization among the anchors introduces uncertainty to the localization results.

Current UWB systems are limited to the update rate set by the manufacturer, so that real time surgical navigation is not possible.

For the IMU system, drifting on the heading remains a primary concern as these systems do not use magnetometers for heading navigation correction.

One significant reason that orientation tracking is not complemented between the two systems is that a single UWB tag is incapable of producing orientations information.

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