Simultaneous calibration method for magnetic localization and actuation systems

Patent metadata

Field	Value
Publication number	US-11717142-B2
Application number	US-201916696605-A
Country	US
Kind code	B2
Filing date	Nov 26, 2019
Priority date	Dec 10, 2018
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

The invention relates to a method of simultaneously calibrating magnetic actuation and sensing systems for a workspace, wherein the actuation system comprises a plurality of magnetic actuators and the sensing system comprises a plurality of magnetic sensors, wherein all the measured data is fed into a calibration model, wherein the calibration model is based on a sensor measurement model and a magnetic actuation model, and wherein a solution of the model parameters is found via a numerical solver order to calibrate both the actuation and sensing systems at the same time.

First claim

The invention claimed is:

1. A method of simultaneously calibrating magnetic actuation and sensing systems for a workspace, wherein the actuation system comprises a plurality of magnetic actuators and the sensing system comprises a plurality of magnetic sensors, the method further comprising the following steps:
generating a plurality of arbitrary magnetic fields at the workspace by applying a plurality of electric currents to the magnetic actuators;
measuring each magnetic field with the sensing system in the workspace and measuring each respective electric current with a current sensor;
measuring a magnetic field of a random known sample magnet with the sensing system at an arbitrary position and orientation in the workspace; and
feeding all the measured data into a calibration model, wherein the calibration model is based on a sensor measurement model and a magnetic actuation model, and finding a solution of the model parameters via a numerical solver in order to calibrate both the actuation and sensing systems at the same time.

2. The method in accordance with claim 1 , wherein the actuation and sensing systems each comprise an actuation system level and a sensing system level, respectively, wherein the workspace is sandwiched in between the actuation system level and the sensing system level.

3. The method in accordance with claim 1 , wherein the magnetic actuators comprise electromagnets.

4. The method in accordance with claim 1 , wherein the magnetic sensors can be on of mono-axial, triaxial and multi-axial sensors.

5. The method in accordance with claim 1 , wherein each of the plurality of generated magnetic fields comprises a non-uniform shape throughout the workspace.

6. The method in accordance with claim 5 , wherein the non-uniform shape is generated from a solenoidal electromagnet.

7. The method in accordance with claim 1 , wherein the calibration model comprises a parameter set, which includes sensor parameters and actuator parameters, wherein the sensor parameters comprise parameters for position, orientation, axis distortion, axes distortion and gain of each sensor, and wherein the actuator parameters comprise parameters for position, orientation and magnetic moment of each actuator.

8. The method in accordance with claim 1 , wherein the sensor measurement model includes a measurement of each generated magnetic field according to

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wherein p s,i is an array of parameters for G i , H x,i , H y,i and H z,i , and wherein H x,i , H y,i and H z,l are symmetric 3×3 matrices which involve rotations and quadratic terms together, G i is a linear mapping which represents effects of scaling, rotation and shear, and v ik is the magnetic senor reading.

9. The method in accordance with claim 1 , wherein recovered B-field values are expressed in a stacked matrix form as

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Assignees

• Max Planck Gesellschaft

Inventors

• Sitti Metin
• Son Donghoon
• Dong Xiaoguang

Classifications

• A61B1/041 Primary

  Capsule endoscopes for imaging · CPC title

• A61B1/000096

  using artificial intelligence · CPC title

• A61B1/00158

  using magnetic field · CPC title

• A61B5/062

  using magnetic field · CPC title

• A61B34/20

  Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis · CPC title