SYSTEM AND METHOD FOR SENSING HUMAN ACTIVITY BY MONITORING IMPEDANCE

• US 20130113506A1
• Filed: 12/26/2012
• Published: 05/09/2013
• Est. Priority Date: 04/08/2010
• Status: Active Grant

• Current Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Original Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Inventors: Poupyrev, Ivan, Yeo, Zhiquan, Loh, Jonas
• Granted Patent: US 9,366,706 B2
• Time in Patent Office: Days
• US Class Current: 324/705
• CPC Class Codes: G01R 27/02 Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant by measuring phase angle only G01R25/00
• 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 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A system for sensing human activity by monitoring impedance includes a signal generator for generating an alternating current (AC) signal, the AC signal applied to an object, a reactance altering element coupled to the AC signal, an envelope generator for converting a returned AC signal to a time-varying direct current (DC) signal, and an analog-to-digital converter for determining a defined impedance parameter of the time-varying DC signal, where the defined impedance parameter defines an electromagnetic resonant attribute of the object.

Claims

1. A system for sensing interaction, comprising:

a signal generator producing a frequency-swept signal in an object;

an impedance measurement component coupled to the object and configured to identify a change in an impedance parameter of the frequency-swept signal as an external body interacts with the object; and

an interaction signal generator indicating a characteristic of an interaction between the object and the external body based upon the change in the impedance parameter.

2. The system of claim 1 wherein the frequency-swept signal comprises a time-varying frequency component that varies within a range of substantially 1 KHz to 3.5 MHz.

3. The system of claim 1 wherein the frequency-swept signal is a periodic electrical signal.

4. The system of claim 1 further comprising:

a reactive component coupled to the signal generator and the impedance measurement component and operable to shift a frequency range in which the signal is swept.

5. The system of claim 1 wherein the characteristic of the interaction indicated by the interaction signal generator comprises one of:

a location of the object contacted by the external body, a pressure of the contact between the object and the external body, and a size of an area of contact between the object and the external body.

6. The system of claim 1 wherein the impedance measurement component is coupled to the object with a single electrode.

7. The system of claim 1 wherein the impedance measurement component identifies the change in the impedance parameter by comparing a first multi-frequency impedance curve of the object measured when the object and the external body are not interacting to a multi-frequency impedance curve measured when the object and the external body are interacting.

8. The system of claim 1 wherein the impedance parameter is at least one of:

a resonant frequency of the frequency-swept signal, amplitude of the frequency-swept signal at a particular frequency, a difference between amplitudes at respective frequencies of the frequency-swept signal, a shape of an impedance curve generated by the frequency-swept signal.

9. A method for sensing a body'"'"'s interaction with an object, comprising:

generating a frequency-swept signal within the object;

identifying a change in an impedance parameter of the frequency-swept signal as the body interacts with the object; and

generating an interaction signal indicating a characteristic of an interaction between the body and the object based upon the change in the impedance parameter.

10. The method of claim 9, wherein the act of generating a frequency-swept signal comprises generating multiple frequencies over a period of time in the range of substantially 1 KHz to 3.5 MHz.

11. The method of claim 9 wherein the act of generating the frequency-swept signal comprises applying an electrical signal periodically to the object.

12. The method of claim 9 wherein the characteristic of the interaction indicated by the interaction signal comprises one of:

a location of the object contacted by the body, a pressure of the contact between the object and the body, and a size of an area of contact between the object and the body.

13. The method of claim 9 wherein the act of generating an interaction signal comprises measuring the impedance parameter of the frequency-swept signal using a single conductor.

14. The method of claim 9, wherein the act of identifying the change in an impedance parameter comprises comparing a first multi-frequency impedance curve of the object measured when the object and the body are not interacting to a multi-frequency impedance curve measured when the object and the body are interacting.

15. The method of claim 9, wherein the impedance parameter is at least one of:

a resonant frequency of the frequency-swept signal, amplitude of the frequency-swept signal at a particular frequency, a difference between amplitudes at respective frequencies of the frequency-swept signal, a shape of an impedance curve generated by the frequency-swept signal.

16. An interactive object, comprising:

a body having a characteristic reactance;

a first interface configured to couple the characteristic reactance to an external scanning impedance monitoring device; and

a second interface configured to couple to a reactance altering element, whereby the characteristic impedance coupled to the scanning impedance monitoring device is distinguishably altered when the second interface is coupled to a reactance altering element.

17. The interactive object of claim 16, wherein the first interface is an electrode configured to permit an electrical signal to flow between the interactive object and the scanning impedance monitoring device, wherein an impedance parameter of the electrical signal is affected when the second interface is coupled to the reactance altering element.