Method and apparatus for reducing errors in screening-test administration

• US 7,127,376 B2
• Filed: 09/23/2003
• Issued: 10/24/2006
• Est. Priority Date: 09/23/2003
• Status: Expired due to Fees

• Current Assignee: Natus Medical Incorporated
• Original Assignee: Neurocom International Inc. (Natus Medical Incorporated)
• Inventors: Nashner, Lewis M.
• Primary Examiner(s): Nghiem, Michael
• Assistant Examiner(s): Lau, Tung S.
• Application Number:
  US10/668,680
• Publication Number:
  US 20050075833A1
• Time in Patent Office: 1,127 Days
• Field of Search: 702/185, 246/122, 360/77, 360/78, 360/75, 365/75, 701/216, 455/456, 435/6, 177/1, 436/148, 375/140, 250/559, 706/22
• US Class Current: 702/185
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/4023 Evaluating sense of balance
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence

Abstract

A system for detecting a screening-test error includes a measurement device that measures at least one performance parameter related to at least one screening-test task and a computational device, in communication with the measurement device. The computational device receives the at least one measured performance parameter, calculates at least one performance statistical quantity characterizing the measured performance parameter, and compares the at least one performance statistical quantity to at least one reference statistical quantity associated with an error-free screening test. In accordance with a related embodiment, the system may further include a display device that displays the extent to which the at least one performance statistical quantity differs from the at least one reference statistical quantity.

Claims

1. A system for detecting errors in balance related screening tests, the system comprising:

a force-plate for measuring forces applied by a subject to determine a quantity related to a balance task performed by the subject in trials under a plurality of distinct sensory conditions; and

a computation device in communication with the force-plate, the computational device

(i) receiving the quantity related to the balance task for each trial,

(ii) determining a rank order for the quantities, each quantity for each trial being associated with a rank, and

(iii) determining if any of the ranks associated with a given one of the trials has fallen outside a reference range associated with the given trial performed under error-free conditions.

2. A system according to claim 1, further comprising a display device in communication with the computational device for indicating an instance wherein any of the ranks associated with a given one of the trials has fallen outside a reference range associated with the given trial.

3. A system according to claim 2, wherein the display device displays a number corresponding to the number of times a performance of the balance task by the subject has fallen outside the reference range.

4. A method, for detecting a screening-test error, the method comprising:

measuring at least one performance parameter related to at least one screening-test task performed by a subject; and

calculating at least one performance statistical quantity characterizing the measured performance parameter; and

comparing the at least one performance statistical quantity to at least one reference statistical quantity associated with an error-free screening test to derive error information; and

displaying the error information on a display device or in a report, wherein;

(i) the screening-test task is a balance task;

(ii) the at least one performance parameter is a quantity related to vertical force applied to a force plate;

(iii) the at least one performance statistical quantity corresponds to an average of a mathematical derivative of the total vertical force applied to the force plate; and

(iv) comparing the at least one performance statistical quantity to the at least one reference statistical quantity includes determining whether the average deviates from zero by a predetermined threshold value,

wherein the statistical quantity represents a value associated with a root mean square.

5. A method for detecting a screening-test error, the method comprising:

measuring at least one performance parameter related to at least one balance task performed by a subject; and

calculating at least one performance statistical quantity characterizing the measured performance parameter; and

comparing the at least one performance statistical quantity to at least one reference statistical quantity associated with an error-free screening test to derive error information; and

displaying the error information on a display device or in a report, wherein;

(i) the at least one performance parameter is a quantity related to vertical force applied to a force plate by the subject;

(ii) the at least one performance statistical quantity corresponds to a moving window average value for total vertical force applied to the force plate; and

(iii) comparing the at least one performance statistical quantity to the at least one reference statistical quantity includes determining whether the moving window average value deviates from a constant value by a predetermined threshold value.

6. A method according to claim 5, wherein the balance task is walking, standing, turning quickly, sitting, stepping, squatting, rhythmic weight shifting or lunging.

7. A method for detecting a screening-test error, the method comprising:

measuring at least one performance parameter related to at least one balance task performed by a subject; and

calculating at least one performance statistical quantity characterizing the measured performance parameter; and

comparing the at least one performance statistical quantity to at least one reference statistical quantity associated with an error-free screening test to derive error information; and

displaying the error information on a display device or in a report, wherein;

(i) the at least one performance parameter is a quantity related to vertical force applied to a force plate by the subject;

(ii) the at least one performance statistical quantity corresponds to an average of a mathematical derivative of the total vertical force applied to the force plate; and

(iii) comparing the at least one performance statistical quantity to the at least one reference statistical quantity includes determining whether the average deviates from zero by a predetermined threshold value.

8. A method according to claim 7, wherein the statistical quantity represents a value associated with an average.

9. A method according to claim 7, wherein the statistical quantity represents a value associated with a standard deviation.

10. A method according to claim 7, wherein the statistical quantity represents a value associated with a standard error.

11. A method according to claim 7, wherein the statistical quantity represents a value associated with a power spectrum.

12. A method according to claim 7, wherein the statistical quantity represents a value associated with a frequency histogram.

13. A method according to claim 7, further comprising displaying the extent to which the at least one performance statistical quantity differs from the at least one reference statistical quantity on a display device.

14. A method according to claim 7, wherein the balance task is walking, standing, turning quickly, sitting, stepping, squatting, rhythmic weight shifting or lunging.

15. A method for detecting a screening-test error, the method comprising:

measuring at least one performance parameter related to at least one balance task performed by a subject; and

calculating at least one performance statistical quantity characterizing the measured performance parameter; and

comparing the at least one performance statistical quantity to at least one reference statistical quantity associated with an error-free screening test to derive error information; and

displaying the error information on a display device or in a report, wherein;

(i) the at least one performance parameter is a quantity related to horizontal force applied to a force plate by the subject;

(ii) the at least one performance statistical quantity corresponds to an average of a mathematical derivative of the total horizontal force applied to the force plate; and

(iii) comparing the at least one performance statistical quantity to the at least one reference statistical quantity includes determining whether the average deviates from zero by a predetermined threshold value.

16. A method according to claim 15, wherein the balance task is walking, standing, turning quickly, sitting, stepping, squatting, rhythmic weight shifting or lunging.

17. A system for detecting errors in balance related screening tests, the system comprising:

a force-plate for measuring forces to determine a quantity related to a stability factor of a balance task performed in trials by a subject under a plurality of distinct sensory conditions; and

a computation device in communication with the force-plate, the computational device

(i) receiving the quantity related to the stability factor for each trial,

(ii) determining a rank order for the quantities, each quantity for each trial being associated with a rank, and

(iii) determining if any of the ranks associated with a given one of the trials has fallen outside a reference range associated with the given trial performed under error-free conditions,

wherein measuring the quantity related to a stability factor includes following a modified CTSIB protocol.

18. A system for detecting errors in balance related screening tests, the system comprising:

a force-plate for measuring forces to determine a quantity related to a stability factor of a balance task performed in trials by a subject under a plurality of distinct sensory conditions; and

a computation device in communication with the force-plate, the computational device

(i) receiving the quantity related to the stability factor for each trial,

(ii) determining a rank order for the quantities, each quantity for each trial being associated with a rank, and

(iii) determining if any of the ranks associated with a given one of the trials has fallen outside a reference range associated with the given trial performed under error-free conditions,

wherein determining a rank order for the performance of the plurality of distinct tasks includes determining a rank order according to the level of difficulty of the balance tasks.