Functional status assessment scale

• US 6,367,314 B1
• Filed: 01/21/2000
• Issued: 04/09/2002
• Est. Priority Date: 01/21/2000
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Melton, Hewlett E. Jr.
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US09/489,446
• Time in Patent Office: 809 Days
• Field of Search: 738/620.41, 738/620.42, 738/620.43, 738/620.44, 738/620.45, 738/620.46, 73/650.1, 73/650.7, 73/650.9
• US Class Current: 73/65.09
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

A system and a method of objectively assessing the functional status of a subject utilize a functional status scale to extract objective measures that are indicative of the subject'"'"'s functional status. The objective measures are extracted from center-of-weight (C.O.W.) data gathered from the functional status scale when the subject is standing on the scale. These objective measures can then be used to assess the current functional status of the subject by a health care provider. The functional status scale can be remotely stationed at the subject'"'"'s home, which eliminates the need for office visits, expensive home nurse visits, telephone interviews or video visits to assess the current functional status of the subject. The functional status scale includes weight sensors that are connected to a C.O.W. computer. The C.O.W. computer is configured to compute x and y coordinates of the C.O.W. from weight signals generated by the weight sensors. These x and y coordinates are then used to extract the objective measures by analysis modules. The objective measures may be statistical measures, frequency domain measures, or other analytical measures that can be utilized for assessment of a subject'"'"'s functional status. In one configuration, the analysis modules are included in remote computers that can access a heath care provider'"'"'s patient database, which receives and stores the x and y coordinates from the functional status scale. In an alternative configuration, the analysis modules are included in the functional status scale.

Claims

1. A system for assessing a physical status of a subject comprising:

a platform having a surface;

a plurality of pressure-sensitive sensors operatively coupled to said platform, said pressure-sensitive sensors being configured to generate signals in response to a force exerted on said surface by said subject situated on said platform;

circuitry operatively coupled to said pressure-sensitive sensors to receive said signals, said circuitry being configured to derive center-of-weight data using said signals from said pressure-sensitive sensors;

a remote device operatively coupled to said circuitry to provide information derived from said center-of-weight data, said information being indicative of said physical status of said subject;

telecommunications devices connected to said circuitry and to said remote device to selectively link said circuitry and said remote device via a telecommunications network, thereby enabling exchanges of data therebetween; and

an analysis module operatively coupled to said circuitry, said analysis module being configured to statistically extract said information from said center-of-weight data to yield at least two of (1) maximum x and y coordinate values as applied to said platform, (2) autocovariances of said x and y coordinate values, (3) autocovariances of response times, (4) standard deviations of said x and y coordinate values, (5) mean magnitude excursions of said x and y coordinates values, (6) maximum rates of change of said x and y coordinate values, (7) cross correlation coefficients between said x and y coordinate values, (8) cross covariances between said x and y coordinates values and (9) cross covariance lengths of said x and y coordinate values.

2. The system of claim 1 wherein said analysis module is configured to perform operations to extract said information from said center-of-weight data when said center-of-weight data is in the time domain and is configured to yield said extracted information in the frequency domain.

3. The system of claim 1 further comprising computer memory for storing said information for subsequent analysis by said analysis module and wherein said analysis module is a component of said remote device.

4. The system of claim 1 wherein said plurality of pressure-sensitive sensors includes four pressure-sensitive sensors that are positioned in a rectangular configuration, and wherein said circuitry is electrically configured to compute first and second coordinates of center-of-weight using signals from said four pressure-sensitive sensors.

5. The system of claim 1 wherein said plurality of pressure-sensitive sensors includes four pressure-sensitive sensors that are positioned in a diamond configuration, and wherein said circuitry is electrically configured to compute first and second coordinates of center-of-weight using signals from said four pressure-sensitive sensors.

6. The system of claim 1 wherein said plurality of pressure-sensitive sensors includes three pressure-sensitive sensors that are positioned in a triangular configuration, and wherein said circuitry is electrically configured to compute first and second coordinates of center-of-weight using signals from said three pressure-sensitive sensors.

7. The system of claim 1 wherein said remote device is operatively coupled to a network of computers.

8. A method of assessing a physical status of a subject comprising steps of:

generating signals that correspond to forces being exerted on a platform by said subject;

computing center-of-weight data by processing said signals, said center-of-weight data being in the time domain;

establishing a communications link between said platform and a remote device; and

analyzing said center-of-weight data to extract measures that are indicative of said physical status of said subject, including determining frequency domain measures from said center-of-weight data, and including performing operations at said remote device to extract statistical measures that are indicative of said physical status of said subject, said statistical measures including at least two of (1) maximum x and y coordinate values as applied to said platform, (2) autocovariances of said x and y coordinate values, (3) autocovariances of response times, (4) standard deviations of said x and y coordinate values, (5) mean magnitude excursions of said x and y coordinates values, (6) maximum rates of change of said x and y coordinate values, (7) cross correlation coefficients between said x and y coordinate values, (8) cross covariances between said x and y coordinates values and (9) cross covariance lengths of said x and y coordinate values.

9. The method of claim 8 wherein said signals are generated by four weight sensors that are operatively coupled to said platform, said four weight sensors being positioned in a rectangular configuration.

10. The method of claim 8 wherein said signals are generated by four weight sensors that are operatively coupled to said platform, said four weight sensors being positioned in a diamond configuration.

11. The method of claim 8 wherein said signals are generated by three weight sensors that are operatively coupled to said platform, said three weight sensors being positioned in a triangular configuration.

12. A method of assessing a physical status of a subject comprising steps of:

generating signals that correspond to forces being exerted on a platform by said subject;

computing center-of-weight data by processing said signals, said center-of-weight data being in the time domain;

establishing a communications link between said platform and a remote device; and

analyzing said center-of-weight data to extract measures that are indicative of said physical status of said subject, including determining frequency domain measures from said center-of-weight data, and including performing operations at said remote device to extract said frequency domain measures as measures of dominant frequency to one of the x and y coordinates related to said platform and a phase of said dominant frequency.

13. The method of claim 12 wherein said signals are generated by four weight sensors that are operatively coupled to said platform, said four weight sensors being positioned in a rectangular configuration.

14. The method of claim 12 wherein said signals are generated by four weight sensors that are operatively coupled to said platform, said four weight sensors being positioned in a diamond configuration.

15. The method of claim 12 wherein said signals are generated by three weight sensors that are operatively coupled to said platform, said three weight sensors being positioned in a triangular configuration.