System and Method for Transmission of Electrical Signals in Imperfectly Conducting Media

Abstract

A system for transmitting a signal through an imperfectly-conducting medium includes a transmitter station and a receiver station. The transmitter station has a transmitter and at least one conductor (electrode). The receiving station has at least one conductor (electrode) and a receiver. The transmitter causes a current to flow from the transmitter conductor to the receiver conductor through the imperfectly-conducting medium. Associated with the current flow is an electric field. Because the current flow varies with the signal, the electric field varies with the signal. The receiving conductor senses the electric field and provides a signal to the receiver which detects the signal to be transmitted. The receiving station then passes the signal to an output device to be output.

Description

[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 014,414, filed Dec. 14, 2001, which claimed the benefit of U.S. Provisional Application No. 60 / 255,852 filed Dec. 15, 2000, which is hereby incorporated by reference herein in its entirety.FIELD OF THE INVENTION[0002]The present invention relates to transmitting signals in imperfectly-conducting media. More specifically, the present invention relates to using an electric field to transmit signals through or near water, the earth, or other imperfectly-conducting media.BACKGROUND OF THE INVENTION[0003]Transmitting signals through imperfectly-conducting media is a notoriously difficult problem. A major reason for this difficulty is that imperfect conductors severely attenuate radio waves traveling through them. This is because, as discussed in Jordan and Balman, “Electromagnetic Waves and Radiating Systems”, Prentice-Hall, 1968, Chapter 5, imperfect conductivity (partial conductivity) causes attenua...

AI Technical Summary

Benefits of technology

The patent describes a way to send signals through a medium that is not perfectly conductive using an electric field. Instead of using electromagnetic radiation, which is affected by the medium's conductivity, the method uses an electric field that is created by conductors at the transmitter and extracted at the receiver. This technique allows for the safe and efficient transmission of signals through imperfect conductors.

Problems solved by technology

Transmitting signals through imperfectly-conducting media is a notoriously difficult problem.

A major reason for this difficulty is that imperfect conductors severely attenuate radio waves traveling through them.

This attenuation renders radio communication under water nearly impossible.

Even where possible, such communication is generally impractical.

Consequently, its use is limited to only a few applications.

Largely because of the difficulties associated with transmitting electromagnetic waves through imperfectly conducting media, most systems that try to transmit signals through such media use acoustic energy, rather than electromagnetic energy.

However, acoustic systems also suffer from a number of drawbacks.

One drawback is that, like electromagnetic waves, acoustic waves suffer significant attenuation in water or earth.

Another drawback is that natural or man-made noise can interfere with acoustic systems.

For example, acoustic noise from surf or storms or engine noise from nearby boats can dramatically affect the performance of underwater acoustic communication

Another problem with acoustic signaling arises from reflections that can occur when properties of the medium through which an acoustic wave propagates vary.

Although useful in some applications such as SONAR, reflection of acoustic waves in a communication system is generally detrimental to the communications.

For example, due to the relatively slow speed of sound propagation in water, reflection of acoustic waves can lead to severe multi-path interference, which causes degradation in intelligibility and loss of communication bandwidth.

Moreover, in some cases, the reflection is so severe that it causes complete loss of signal results due to reflection of the acoustic signal wave away from the desired transmission path.

There has been little research exploring the use of the imperfect conductivity of the medium as a beneficial feature, rather than a detriment, to communication systems.

Consequently, it is limited in its application.

However, these networks do not provide for stimulation output or for other outputs to affect the body.

However, the BION system does not use an electrical transmission method, instead the BION system uses a magnetic field that is picked up by a receiving coil in the implanted device.

Providing this coil can be very cumbersome.

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