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.

What is claimed is: 
     
         1 . A system for providing electrical stimulation to a body comprising:
 (a) a transmitter station, the transmitter station comprising:   a transmitter for producing a signal having a frequency spectrum that does not directly cause stimulation of muscle tissue within a body;   transmitter electrode means coupled to the transmitter and to the body whereby a signal produced by the transmitter causes a current to flow from the transmitter electrode means through the body to thereby generate an electric field in the body that transmits the signal;   (b) a receiver station, the receiver station comprising:   a receiver, the receiver comprising pulse-generation means for producing a muscle tissue stimulating waveform in response to a signal inputted to the receiver in a frequency spectrum that causes muscle tissue stimulation within a body;   receiver electrode means coupled to the body and coupled to the receiver whereby a signal, received by the receiver electrode means by being within the electric field in the body, is inputted to the receiver from the receiver electrode means;   stimulation electrode means coupled to the receiver whereby electrical current corresponding to the muscle tissue stimulating waveform produced by the receiver in response to a signal inputted to the receiver from the receiver electrode means flows from the stimulation electrode means into the body; and   (c) a wireless, partially conductive path in the body that causes the electric field generated by a current flow from the transmitter electrode means through the body to encompass the receiver electrode means whereby a signal produced by the transmitter is received by the receiver electrode means and inputted to the receiver.   
     
     
         2 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the transmitter electrode means comprises two transmitter electrodes; the receiver electrode means comprises two receiver electrodes; and the stimulation electrode means comprises two stimulation electrodes.   
     
     
         3 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the receiver electrode means and the stimulation electrode means comprise a multi-purpose electrode that is at least partially covered by a protective insulating layer; and the insulating layer of the multi-purpose electrode, at the frequency of the signal, has less impedance than at the frequency of the stimulation waveform whereby the multi-purpose electrode presents a different and greater effective surface area for the signal than for the stimulation waveform.   
     
     
         4 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the receiver electrode means and the stimulation electrode means comprise a multi-purpose electrode.   
     
     
         5 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the transmitter of the transmitter station is attached to and located outside the body and the transmitter electrode means is coupled to the skin of the body whereby the transmitter of the transmitter station can be installed, removed, and serviced without surgical procedures.   
     
     
         6 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the transmitter electrode means of the transmitter station is located inside the body whereby the transmitter electrode means of the transmitter station will not suffer inadvertent disconnection from the body.   
     
     
         7 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the transmitter produces an amplitude-modulated signal having a modulation envelope corresponding to the stimulation waveform; and   the pulse generation means of the receiver comprises envelope detection means whereby the stimulation waveform produced by the pulse generation means corresponds to the modulation envelope of the amplitude-modulated signal.   
     
     
         8 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the transmitter produces a signal that is a variable frequency-modulated signal; and   the pulse generation means of the receiver produces a stimulation waveform is a variable stimulation waveform that corresponds to the frequency modulation of the signal.   
     
     
         9 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the receiver further comprises energy storing means which stores electrical energy inputted to the energy storing means from the receiving electrode means whereby energy stored in the energy storage means is used to provide the stimulation waveform generated by the pulse-generation means with more energy than is instantaneously available from the receiving electrode means.   
     
     
         10 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the transmitter of the transmitter station produces a signal with encoded digital information; and   the pulse generation means of the receiver comprises digital circuitry that interprets the digital information.   
     
     
         11 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the receiver, the receiver electrode means, and the stimulation electrode means are contained within a single enclosure.   
     
     
         12 . The system for providing electrical stimulation to a body according to  claim 1 , wherein:
 the partially conductive path further comprises a high-potential location;   the receiver electrode means comprises two receiver electrodes; and   the two receiver electrodes are situated within the high-potential location to increase the electric field at the two receiver electrodes.   
     
     
         13 . A method for providing electrical stimulation to a body comprising:
 producing a signal having a frequency spectrum that does not directly cause stimulation of muscle tissue within a body and coupling the signal to a body with transmitter electrode means;   causing a current to flow from the transmitter electrode means through a body along a wireless, partially conductive path to thereby generate along the path an electric field in the body that transmits the signal;   receiving the signal with receiver electrode means coupled to the body and located along the path within the electric field;   producing a muscle tissue stimulating waveform with a pulse-generation means in response to the signal received by the receiver electrode means in a frequency spectrum that causes muscle tissue stimulation within a body; and   introducing the muscle tissue stimulating waveform into the body with stimulation electrode means coupled to the body.   
     
     
         14 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the transmitter electrode means comprises two transmitter electrodes; the receiver electrode means comprises two receiver electrodes; and the stimulation electrode means comprises two stimulation electrodes.   
     
     
         15 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the receiver electrode means and the stimulation electrode means comprise a multi-purpose electrode that is at least partially covered by a protective insulating layer; and the insulating layer of the multi-purpose electrode, at the frequency of the signal, has less impedance than at the frequency of the stimulation waveform whereby the multi-purpose electrode presents a different and greater effective surface area for the signal than for the stimulation waveform.   
     
     
         16 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the receiver electrode means and the stimulation electrode means comprise a multi-purpose electrode.   
     
     
         17 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the signal is produced by a transmitter attached to and located outside the body and the transmitter electrode means is coupled to the skin of the body whereby the transmitter can be installed, removed, and serviced without surgical procedures.   
     
     
         18 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the signal is produced by a transmitter having a transmitter electrode means located inside the body whereby the transmitter electrode means will not suffer inadvertent disconnection from the body.   
     
     
         19 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the signal is an amplitude-modulated signal having a modulation envelope corresponding to a desired stimulation waveform; and   the signal is converted to a desired stimulation waveform that corresponds to the modulation envelope of the amplitude-modulated signal for introduction into the muscle tissue with stimulation electrode means.   
     
     
         20 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the signal is a variable frequency-modulated signal; and   the stimulation waveform is a variable stimulation waveform that corresponds to the frequency modulation of the signal.   
     
     
         21 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 storing energy from the receiving electrode means whereby the energy stored is used to provide the stimulation waveform with more energy than is instantaneously available from the receiving electrode means.   
     
     
         22 . The method for providing electrical stimulation to a body according to  claim 13 , wherein:
 the signal comprises encoded digital information; and   the digital information is interpreted to produce the muscle tissue stimulating waveform.   
     
     
         23 . The method for providing electrical stimulation to a body according to  claim 14 , wherein:
 the partially conductive path further comprises a high-potential location;   the receiver electrode means comprises two receiver electrodes; and   the two receiver electrodes are situated within the high-potential location to increase the electric field at the two receiver electrodes.