Force measurement system

• US 10,010,286 B1
• Filed: 09/22/2017
• Issued: 07/03/2018
• Est. Priority Date: 01/19/2013
• Status: Active Grant

• Current Assignee: Bertec Corporation
• Original Assignee: Bertec Corporation
• Inventors: Berme, Necip, Barnes, Scott Zerkle
• Primary Examiner(s): Amini, Javid A
• Application Number:
  US15/713,166
• Time in Patent Office: 284 Days
• Field of Search: 345633
• CPC Class Codes: A61B 3/032 Devices for presenting test symbols or characters, e.g. test chart projectors A61B3/036 takes precedence
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: A61B 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A61B 5/163 by tracking eye movement, gaze, or pupil change
• CPC Class Codes: A61B 5/4023 Evaluating sense of balance
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01L 5/162 of piezoresistors
• CPC Class Codes: G01L 5/1627 of strain gauges using piezoresistors G01L5/162
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/0334 Foot operated pointing devices
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00

Abstract

A force measurement system is disclosed herein. The force measurement system includes a force measurement assembly configured to receive a subject thereon, a visual display device having an output screen, and one or more data processing devices operatively coupled to the force measurement assembly and the visual display device. In the one or more embodiments, the force measurement assembly is a static force plate and the visual display device is a head-mounted visual display device or a visual display device having an output screen configured to at least partially circumscribe three sides of a torso of the subject. In one or more other embodiments, the force measurement assembly is a displaceable force plate and the visual display device is a head-mounted visual display device.

Claims

1. A force measurement system, comprising:

a force measurement assembly configured to receive a subject, the force measurement assembly including;

a surface for receiving at least one portion of the body of the subject; and

at least one force transducer, the at least one force transducer configured to sense one or more measured quantities and output one or more signals that are representative of forces and/or moments being applied to the surface of the force measurement assembly by the subject;

at least one visual display device having an output screen configured to at least partially circumscribe three sides of a torso of the subject, the at least one visual display device configured to display one or more scenes on the output screen so that the scenes are viewable by the subject, wherein the one or more scenes are configured to create a simulated environment for the subject, wherein the output screen of the at least one visual display device comprises an overhanging top portion and a bottom portion configured to curve inwardly towards the subject, and wherein the output screen of the at least one visual display device further comprises a bottom cutout in the bottom portion of the output screen that is configured to receive a portion of the body of the subject therein, the bottom cutout defining a bottom cutout footprint, the bottom cutout footprint being smaller than an overall footprint of the output screen; and

a data processing device operatively coupled to the force measurement assembly and the at least one visual display device, the data processing device configured to receive the one or more signals that are representative of the forces and/or moments being applied to the surface of the force measurement assembly by the subject, and to convert the one or more signals into output forces and/or moments.

2. The force measurement system according to claim 1, wherein the force measurement assembly is in the form of a static force plate that remains stationary while the subject is disposed thereon, and wherein the force measurement assembly does not have any actuators or other devices that translate or rotate the surface of the force measurement assembly.

3. The force measurement system according to claim 1, wherein the output screen of the at least one visual display device engages enough of the peripheral vision of the subject such that the subject becomes immersed in the simulated environment.

4. The force measurement system according to claim 1, wherein the at least one visual display device comprises a projector having a fisheye lens and a concavely shaped projection screen, wherein the projector is configured to project an image through the fisheye lens, and onto the concavely shaped projection screen, and wherein the overhanging top portion of the output screen of the at least one visual display device comprises a top cutout defining a top cutout footprint, the fisheye lens of the projector being disposed within the top cutout footprint of the top cutout.

5. The force measurement system according to claim 1, wherein the force measurement assembly is vertically aligned with the bottom cutout in the bottom portion of the output screen.

6. The force measurement system according to claim 1, wherein the data processing device is further configured to manipulate the one or more scenes on the output screen of the visual display device so as to perturb a visual input of the subject during the performance of a balance test or training routine where one or more sensory inputs of the subject are modified.

7. The force measurement system according to claim 6, wherein the data processing device is further configured to utilize the output forces and/or moments in order to assess a response of the subject to the one or more manipulated scenes on the output screen of the visual display device.

16. The force measurement system according to claim 7, wherein the data processing device is further configured to assess a response of the subject to the one or more manipulated scenes on the output screen of the visual display device by determining one of the following:

(i) a quantitative score of the subject'"'"'s sway during trials of a test or training routine, (ii) the type of strategy used by the subject to maintain his or her balance during the trials of the test or training routine, (iii) changes in a center of gravity of the subject during the trials of the test or training routine, (iv) one or more quantitative sensory scores indicative of which sensory system or systems of the subject are impaired, (v) the weight symmetry of the subject, (vi) the amount of force that the subject is able to exert in order to bring his or her body back to equilibrium after a perturbation, and (vii) the sway energy of the subject in response to a perturbation.

8. A force measurement system, comprising:

a force measurement assembly configured to receive a subject, the force measurement assembly including;

a top surface for receiving at least one portion of the body of the subject; and

at least one force transducer, the at least one force transducer configured to sense one or more measured quantities and output one or more measurement signals that are representative of forces and/or moments being applied to the top surface of the force measurement assembly by the subject;

at least one actuator operatively coupled to the force measurement assembly, the at least one actuator configured to displace the force measurement assembly;

a base assembly having a stationary portion and a displaceable portion, the force measurement assembly forming a part of the displaceable portion of the base assembly, and the at least one actuator configured to displace the force measurement assembly relative to the stationary portion of the base assembly within a recess defined by the base assembly;

a visual display device having an output screen, the visual display device configured to display one or more scenes on the output screen so that the scenes are viewable by the subject, wherein the one or more scenes are configured to create a simulated environment for the subject, wherein the output screen of the visual display device comprises a bottom cutout in a bottom portion of the output screen that is configured to receive a portion of the body of the subject therein, the bottom cutout defining a bottom cutout footprint, the bottom cutout footprint being smaller than an overall footprint of the output screen; and

one or more data processing devices operatively coupled to the force measurement assembly, the at least one actuator, and the visual display device, the one or more data processing devices configured to receive the one or more measurement signals that are representative of the forces and/or moments being applied to the top surface of the force measurement assembly by the subject, and to convert the one or more measurement signals into output forces and/or moments, the one or more data processing devices further configured to selectively displace the force measurement assembly using the at least one actuator.

9. The force measurement system according to claim 8, wherein the at least one actuator is configured to rotate the force measurement assembly relative to the stationary portion of the base assembly about a transverse rotational axis.

10. The force measurement system according to claim 9, wherein the at least one actuator comprises a first actuator configured to rotate the force measurement assembly about the transverse rotational axis and a second actuator configured to translate the displaceable portion of the base assembly that includes the force measurement assembly.

11. The force measurement system according to claim 8, wherein the one or more data processing devices are further configured to displace the force measurement assembly so as to perturb a proprioceptive input of the subject during the performance of a balance test or training routine where one or more sensory inputs of the subject are modified.

12. The force measurement system according to claim 11, wherein the one or more data processing devices are further configured to utilize the output forces and/or moments in order to assess a response of the subject to the displacement of the force measurement assembly.

13. The force measurement system according to claim 8, wherein the one or more data processing devices are further configured to manipulate the one or more scenes on the output screen of the visual display device so as to perturb a visual input of the subject during the performance of a balance test or training routine where one or more sensory inputs of the subject are modified.

14. The force measurement system according to claim 13, further comprising an eye movement tracking device configured to track eye movement and/or eye position of the subject while the subject performs the balance test or training routine, the eye movement tracking device being configured to output one or more eye tracking signals to the one or more data processing devices;

and

wherein the one or more data processing devices are further configured to utilize the eye tracking signals in order to assess a response of the subject to the perturbed visual input.

17. The force measurement system according to claim 8, wherein the visual display device comprises a projector having a fisheye lens and a concavely shaped projection screen with an overhanging top portion and the bottom portion, wherein the projector is configured to project an image through the fisheye lens, and onto the concavely shaped projection screen, and wherein the overhanging top portion of the concavely shaped projection screen comprises a top cutout defining a top cutout footprint, the fisheye lens of the projector being disposed within the top cutout footprint of the top cutout.

15. A force measurement system, comprising:

a force measurement assembly configured to receive a subject, the force measurement assembly including;

a surface for receiving at least one portion of the body of the subject; and

at least one force transducer, the at least one force transducer configured to sense one or more measured quantities and output one or more signals that are representative of forces and/or moments being applied to the surface of the force measurement assembly by the subject;

a visual display device having an output screen, the visual display device configured to display one or more scenes on the output screen so that the scenes are viewable by the subject, wherein the one or more scenes are configured to create a simulated environment for the subject, wherein the output screen of the visual display device comprises a bottom cutout in a bottom portion of the output screen that is configured to receive a portion of the body of the subject therein, the bottom cutout defining a bottom cutout footprint, the bottom cutout footprint being smaller than an overall footprint of the output screen; and

a data processing device operatively coupled to the force measurement assembly and the visual display device, the data processing device configured to receive the one or more signals that are representative of the forces and/or moments being applied to the surface of the force measurement assembly by the subject, and to convert the one or more signals into output forces and/or moments;

wherein the force measurement assembly is in the form of a static force plate that remains stationary while the subject is disposed thereon, and wherein the force measurement assembly does not have any actuators or other devices that translate or rotate the surface of the force measurement assembly.

18. The force measurement system according to claim 15, wherein the visual display device comprises a projector having a fisheye lens and a concavely shaped projection screen with an overhanging top portion and the bottom portion, wherein the projector is configured to project an image through the fisheye lens, and onto the concavely shaped projection screen, and wherein the overhanging top portion of the concavely shaped projection screen comprises a top cutout defining a top cutout footprint, the fisheye lens of the projector being disposed within the top cutout footprint of the top cutout.