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：US11428546B2

公开(公告)日：2022-08-30

申请号：US16282782

申请日：2019-02-22

Applicant: PENUMBRA, INC.

Inventor： Igor Khalfin ,  Amir Rubin ,  Oded Y. Zur

IPC: G01D5/20 ,  G01B7/004 ,  A61B5/103 ,  G01S3/00 ,  A61B5/11 ,  A61B5/06

Abstract: A method and apparatus is disclosed for allowing a magnetic tracking system to detect, and operate in close proximity in the same physical environment with, additional magnetic tracking systems. The first user's magnetic tracking system that becomes active in the physical space becomes the master system, and assigns time slots for its own transmitting antennas to generate the magnetic field which is used to determine the position and orientation of the user's limbs relative to the user's head. The master system also determines when other magnetic tracking systems become active in the physical space and assigns to those systems identification codes and time slots for their transmitting antennas to generate a magnetic field so that the position and orientation of the user's hands relative to the user's head for each of those systems may be determined. By requiring each magnetic tracking system to operate in different time slots, there is no interference between the systems.

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：US11486958B2

公开(公告)日：2022-11-01

申请号：US16368543

申请日：2019-03-28

Applicant: PENUMBRA, INC.

Inventor： Oded Y. Zur ,  Alejandro Santiago Diaz ,  Michael D. Collins ,  Ran Bar-On ,  Ron Barak ,  Amir Rubin

IPC: G01S5/02 ,  G01S17/875 ,  G06N7/00 ,  G01S3/32

Abstract: A method and apparatus for reducing magnetic tracking error in the position and orientation determined in an electromagnetic tracking system is disclosed. In some embodiments, a corrected position and orientation is blended with an uncorrected position and orientation based upon the calculated probability of each. To determine a corrected position and orientation, data from an IMU in the receiver is used to obtain a constraint on the orientation. In other embodiments, the amount of detected error due to electromagnetic distortion is measured. Any error is first assumed to be from “floor distortion,” and a correction is applied. If the error is still deemed too great, a constraint is again obtained from IMU data. Using this constraint, another correction for the distortion is made. The solution from this correction may be blended with a standard solution and the solution from the floor distortion to arrive at a final solution.

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：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.