Data transmission system using a human body as a signal transmission path

Abstract

A data transmission system using a human body as a signal transmission path includes a transmitter and a receiver. The transmitter uses a pair of electrodes which are held in close proximity to the skin of the human body. The transmitter transmits data to the receiver through the signal transmission path partly extending through the human body when a user carrying the transmitter touches a touch electrode of the receiver. The electrodes are integrated into a garment worn by the user in such a manner that the electrodes are kept in a closely facing relation to the skin of the user, thereby establishing the electrical path extending through the human body. With the integration of the two electrodes into the garment, the user wearing the garment as an everyday clothes or uniform can be easy and convenient to carry the transmitter for successful transmission of the data.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present patent document is a continuation of U.S. application Ser. No. 09 / 948,638 filed on Sep. 10, 2001, and in turn claims priority to JP 2001-138479 filed on May 9, 2001, the entire contents of each of which are herein incorporated by reference.BACKGROUND ART [0002] 1. Field of the Invention [0003] The present invention relates to a data transmission system using a human body as a signal path, and more particularly to a system composed of a wearable transmitter, a receiver adapted to be connected to an associated equipment which utilize data transmitted from the transmitter, and a garment integrally holding two electrodes for passing the data through the human body. [0004] 2. Description of the Prior Art [0005] U.S. patent application Ser. No. 09 / 605,357 discloses a data transmission system using the human body as a signal path. The system includes a portable transmitter in the form of a wrist watch to be worn on a user, and a si...

AI Technical Summary

Benefits of technology

[0006] In view of the above inconvenience, the present invention has been achieved to provide a data transmission system which is capable of assuring successful data transmission without requiring a special attention to the user. The system in accordance with the present invention comprises a transmitter adapted to be carried by the user and a receiver adapted to be connected to an associated equipment which utilizes data transmitted from the transmitter. The transmitter has a ground electrode to be placed in close proximity to the human body, a signal electrode to be placed also in close proximity to the human body in a spatially spaced relation from the ground electrode, a data memory storing first data, a first modulator for converting the first data into a first modulated voltage signal, and a first signal transmitter which applies the first modulated voltage signal across the signal electrode and the ground electrode. The receiver includes a circuit ground adapted to be connected to the ground, a touch electrode adapted for direct contact with a portion of the human body carrying the transmitter, a signal detector connected across the signal electrode and the circuit ground to detect the first modulated voltage signal, and a demodulator which converts the first modulated voltage signal back into the first data. The characterizing feature of the present invention resides in that the system includes a garment which is adapted to be worn by a user and integrates the ground and signal electrodes in such a manner that at least one of the electrodes is kept in a closely facing relation to the skin of the user, thereby establishing an electrical path extending through a portion of the human body for signal transmission from the transmitter to the receiver. With the integration of the two electrodes into the garment, the user wearing the garment as an everyday clothes or uniform such as a white gown can be easy and convenient to carry the transmitter for successful transmission of the data to the receiver.

[0007] Preferably, each of the ground and signal electrodes is formed by a plurality of electrically conductive threads and is sewed to be integrated into the garment. Thus, the electrodes can be easily integrated into the garment and cannot sacrifice comfortableness of the garment. Each electrode made of the electrically conductive threads can be woven into a fabric so as to be lined on the garment. Alternatively, the electrode of the conductive threads can be woven into an indispensable part of the garment. With the use of the electrical conductive threads, the garment provided with the resulting electrodes can be washed like ordinary clothes, which enhances availability of the system.

[0008] The ground electrode is preferred to be located on the garment closer to the foot of the user than the signal electrode for establishing a consistent electrical path through the human body. That is, the electrical path is composed of a first fraction path extending from the ground electrode down to the foot of the user and through the ground to the circuit ground of the receiver, and a second fraction path extending from the signal electrode towards and through a finger of the user to the touch electrode of the receiver without interfering the first fraction path, thereby assuring efficient and reliable data transmission.

[0009] In a preferred embodiment where both of the ground and signal electrodes are held on the garment so as to come into a closely facing relation with the skin of the user, the transmitter has a case which accommodates an electrical circuitry realizing the first modulator and the first signal transmitter, and which is formed as a separate article from the electrodes. The case is provided with terminals for electrically connecting the circuitry with the ground and signal electrodes. In this connection, the garment is additionally provided with a ground lead and a signal lead which extend respectively from the ground and signal electrodes for connection with the terminals of the case. Both of the ground and signal leads are formed by a strand of the electrically conductive threads and are sewed on the garment. Thus, the leads can be also easily and consistently integrated into the garment to retain comfortableness of the garment.

Problems solved by technology

Thus, the electrodes can be easily integrated into the garment and cannot sacrifice comfortableness of the garment.

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