公开(公告)号：US20230089646A1

公开(公告)日：2023-03-23

申请号：US17834184

申请日：2022-06-07

Applicant: PENUMBRA, INC.

Inventor： Cameron J. Mahon ,  Oded Y. Zur ,  Alejandro S. Diaz

IPC: G01R33/00

Abstract: A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.

公开(公告)号：US11976921B2

公开(公告)日：2024-05-07

申请号：US17834173

申请日：2022-06-07

Applicant: PENUMBRA, INC.

Inventor： Michael D. Collins ,  Alejandro S. Diaz ,  Oded Y. Zur ,  Cameron J. Mahon ,  Branislav Vasilijevic ,  Amir Rubin

IPC: G01R33/025 ,  G01B7/00

CPC classification number: G01B7/003 ,  G01R33/025

Abstract: A method and apparatus for reducing magnetic tracking error in the position and orientation determined in a magnetic tracking system having a magnetic field generator. In some embodiments, the measured position and orientation of a sensor is compared to an expected theoretical position and orientation. Any error is assumed to be from “floor distortion,” i.e., eddy currents in the floor caused by the magnetic field generated by the magnetic field transmitter. The floor distortion is modeled as being caused by eddy currents caused by a second magnetic field transmitter that is a reflection of the actual transmitter. An algorithm iteratively searches over a parameter space to minimize the difference between the measured position and orientation and the theoretical position and orientation, and applies a correction to the measured position and orientation. The measurements and corrections of the position and orientation run in real-time with no additional hardware or calibration required.

公开(公告)号：US11762000B1

公开(公告)日：2023-09-19

申请号：US17841844

申请日：2022-06-16

Applicant: PENUMBRA, INC.

Inventor： Cameron J. Mahon

IPC: G09G5/00 ,  G01R29/08 ,  G06F3/0346 ,  G06F3/01 ,  G06F3/14

CPC classification number: G01R29/0892 ,  G06F3/011 ,  G06F3/0346 ,  G06F3/14

Abstract: A measurement device and methods for detecting distortion or interference in an environment are described herein. The measurement device comprises a transmitter and a receiver attached to a rigid body such that a position and orientation (P&O) of the receiver with respect to the transmitter is fixed. When measuring distortion, the transmitter transmits electromagnetic waves over one or more frequency channels and measures electromagnetic waves over the channel(s) and a P&O of the receiver relative to the transmitter may be computed. Based on the computed P&O and the known P&O of the receiver with respect to the transmitter, the system determines a level of distortion that would cause the change in position and orientation. When measuring interference, the transmitter does not transmit electromagnetic waves and the receiver measures the electromagnetic waves in the environment. The measurement device is moved to identify locations where the measurements of distortion and/or interference are below a threshold value.

公开(公告)号：US20230083524A1

公开(公告)日：2023-03-16

申请号：US17834173

申请日：2022-06-07

Applicant: PENUMBRA, INC.

Inventor： Michael D. Collins ,  Alejandro S. Diaz ,  Oded Y. Zur ,  Cameron J. Mahon ,  Branislav Vasilijevic ,  Amir Rubin

IPC: G01B7/00 ,  G01R33/025

Abstract: A method and apparatus for reducing magnetic tracking error in the position and orientation determined in a magnetic tracking system having a magnetic field generator. In some embodiments, the measured position and orientation of a sensor is compared to an expected theoretical position and orientation. Any error is assumed to be from “floor distortion,” i.e., eddy currents in the floor caused by the magnetic field generated by the magnetic field transmitter. The floor distortion is modeled as being caused by eddy currents caused by a second magnetic field transmitter that is a reflection of the actual transmitter. An algorithm iteratively searches over a parameter space to minimize the difference between the measured position and orientation and the theoretical position and orientation, and applies a correction to the measured position and orientation. The measurements and corrections of the position and orientation run in real-time with no additional hardware or calibration required.

公开(公告)号：US11914005B2

公开(公告)日：2024-02-27

申请号：US18201361

申请日：2023-05-24

Applicant: PENUMBRA, INC.

Inventor： Cameron J. Mahon ,  Oded Y. Zur ,  Alejandro S. Diaz

IPC: G01R33/00

CPC classification number: G01R33/0017 ,  G01R33/0088

Abstract: A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.

公开(公告)号：US20230296697A1

公开(公告)日：2023-09-21

申请号：US18201361

申请日：2023-05-24

Applicant: PENUMBRA, INC.

Inventor： Cameron J. Mahon ,  Oded Y. Zur ,  Alejandro S. Diaz

IPC: G01R33/00

CPC classification number: G01R33/0017 ,  G01R33/0088

Abstract: A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.

公开(公告)号：US11693063B2

公开(公告)日：2023-07-04

申请号：US17834184

申请日：2022-06-07

Applicant: PENUMBRA, INC.

Inventor： Cameron J. Mahon ,  Oded Y. Zur ,  Alejandro S. Diaz

IPC: G01R33/00

CPC classification number: G01R33/0017 ,  G01R33/0088

Abstract: A system and method that can automatically select a frequency of a magnetic field in a magnetic tracking system. A magnetic tracking system emits an alternating magnetic field using a set of three frequencies. In the present approach, a transmitter is capable of generating multiple sets of three frequencies. A processor selects a first set of frequencies to use and causes the receiver to measure the amplitude of the magnetic field at those frequencies. In one embodiment, the frequency set having the lowest energy is selected. The processor then compares an estimated jitter at those frequencies to the actual jitter experienced using the frequencies. If the actual jitter exceeds the estimated jitter by a predetermined amount, the processor switches to a different set of frequencies and causes the receiver to measure the magnetic field at the new set of frequencies. The process may repeat using the additional sets of frequencies.