Non-contact system for sensing and signalling by externally induced intra-body currents
First Claim
1. A wireless communication system including:
- A. a transmitter for producing low frequency signals that include data, the transmitter being capacitively coupled to a user and to ground, the transmitter passing to the user a current that is associated with the low frequency signals; and
B. a receiver that is displaced from the user and is coupled to ground for receiving when capacitively coupled to the user a current that is associated with the signals produced by the transmitter, the receiver reproducing the transmitted signals and recovering the data.
1 Assignment
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Accused Products
Abstract
A wireless system includes one or more transmitters and one or more remote receivers that are respectively coupled through one or more users and room ground. The transmitters each produce low-frequency, low power signals that, through capacitive coupling, pass as displacement currents into and from the body of the user, which acts as a conductive node. A receiver that couples capacitively to the user responds to the displacement currents and reproduces the signals. The transmitter includes a signal generator and a pair of electrodes. The signal generator produces modulated signals that vary the voltage between the electrodes, a first one of which is closely coupled capacitively to the user'"'"'s body such that the "quasi-electrostatic" field resulting from the electrode potential causes a displacement current to pass to the user'"'"'s body. The second electrode is oriented so that its coupling to the room ground is stronger than that of the first electrode, such that room ground acts as a return path for the current from the receiver. The signal generator may modulate the information to be transmitted using, for example, a pseudorandom code, to produce spread spectrum signals. This increases noise immunity and allows multiple transmitters, each using a different modulation code, to operate at the same time. The receivers each include a detector/demodulator that acquires and tracks the signals from the one or more transmitters.
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Citations
25 Claims
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1. A wireless communication system including:
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A. a transmitter for producing low frequency signals that include data, the transmitter being capacitively coupled to a user and to ground, the transmitter passing to the user a current that is associated with the low frequency signals; and B. a receiver that is displaced from the user and is coupled to ground for receiving when capacitively coupled to the user a current that is associated with the signals produced by the transmitter, the receiver reproducing the transmitted signals and recovering the data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 21, 22, 23, 24, 25)
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11. A computer system including:
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A. a screen for displaying on-screen objects; B. a keyboard for data entry to the system; C. a transmitter for producing low frequency signals, the transmitter being capacitively coupled to a user to pass to the user a current that is associated with the low frequency signals; D. a plurality of receivers mounted on the periphery of the screen, each of the receivers in the plurality receiving from the user, through capacitive coupling to the user, a current that is associated with the signals produced by the transmitter, the receivers determining the position of the closest extremity of the user'"'"'s body relative to one or more of the receivers; and E. a processor for controlling the screen display, the processor directing the screen to display the objects in positions that correspond to the position of the user'"'"'s extremity as determined by the receivers. - View Dependent Claims (12, 13)
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14. A wireless communication system including:
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A. a plurality of transmitters for producing low frequency signals, the transmitters being capacitively coupled to one or more users and to ground and, respectively, including a pair of electrodes and connected between the electrodes a signal generator that generates low frequency signals, each transmitter passing to the associated user a current that is associated with the low frequency signals; and B. a plurality of receivers coupled to ground for receiving, respectively, from the one or more users to which they capacitively couple one or more currents associated with the signals produced by the transmitters, the receivers reproducing the transmitted signals; and C. a processor for determining from the signals reproduced by the receivers the respective positions of the users relative to one or more of the receivers. - View Dependent Claims (15, 16, 17)
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18. A system including:
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A. a screen for displaying one or more on-screen objects including a cursor; B. a keyboard for data entry to the system; C. a transmitter for producing low frequency signals, the transmitter being capacitively coupled to a user to pass to the user a current that is associated with the low frequency signals; D. a plurality of receivers mounted on the periphery of the screen, each of the receivers in the plurality receiving from the user, through capacitive coupling to the user, a current that is associated with the signals produced by the transmitter, the receivers determining the position of the closest extremity of the user'"'"'s body relative to one or more of the receivers; E. a selection receiver mounted on the system for determining, based on the strength of the received signals, if the user is selecting the information that is displayed below the cursor, the system determining that the user is selecting the information if the strength of the signals received by the selection receiver is above a predetermined threshold; and F. a processor for controlling the screen display, the processor directing the screen to display one or more of the objects in positions that correspond to the position of the user'"'"'s extremity as determined by one or more of the plurality of the receivers. - View Dependent Claims (19, 20)
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Specification