Patent US3328683A successfully refreshed from Google Patents.
US3880146A
Expired / Lapsed
US
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Noise compensation techniques for bioelectric potential sensing
Assignee: Individual
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Filing: 1973-06-04
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Granted: 1975-04-29
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Expires: 1993-06-04
Abstract
Abstract A measuring circuit having one or more inputs connected to one or more bioelectric sensing electrodes couples its output to a waveform display or recording device in a manner to remain ungrounded and additionally has its common point maintained at the common voltage of a body under measurement. Undesirable common voltage variations in the body other than the desired bioelectric signal are sensed and the amplifier common point is varied in voltage in a similar way. A second amplifier connected in a unity gain voltage follower mode has an output that drives the amplifier common point. This second amplifier is connected to two electrodes, one of which is connected to an input of the second amplifier and the other of which is connected to a common reference point of the second amplifier.
Inventors
- 👤 Donald B Everett
- 👤 Louis W Schlenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:31
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/0002; A61B5/0004; A61B5/0006; A61B5/24; A61B5/30; A61B5/307; A61B5/308
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
138 words
In a method of measuring bioelectric potentials across a body comprising the steps of locating at least two electrodes at at least first and second spaced apart positions on said body, and electronically subtracting the potentials detected by the electrodes to obtain a signal representative of the desired bioelectric potential across the body with respect to a voltage common point, an improved method of coupling said common point to the body comprising the steps of: positioning two additional electrodes on said body, electronically connecting one of said two additional electrodes to an input of a high impedance amplifier connected in a unity gain voltage follower mode, connecting the other of said two additional electrodes to a common terminal of said amplifier, and transferring the electrical poteNtial at an output of said voltage amplifier to said voltage common point.
Claim 2
Dependent Claim
138 words
In a method of measuring bioelectric potentials across a body comprising the steps of locating at least two electrodes at at least first and second spaced apart positions on said body, and electronically subtracting the potentials detected by the electrodes to obtain a signal representative of the desired bioelectric potential across the body with respect to a voltage common point, an improved method of coupling said common point to the body comprising the steps of: positioning two additional electrodes on said body, electronically connecting one of said two additional electrodes to an input of a high impedance amplifier connected in a unity gain voltage follower mode, connecting the other of said two additional electrodes to a common terminal of said amplifier, and transferring the electrical poteNtial at an output of said voltage amplifier to said voltage common point.
Claim 3
Dependent Claim
63 words
The improved method of claim 1 wherein said coupling step includes coupling without the use of an earth ground connection, the improvement comprising the additional step of coupling said bioelectric potential representative signal to a display apparatus without use of any wired electrical connection, whereby said display apparatus may be connected to an earth ground without grounding the bioelectric potential signal producing equipment.
Claim 4
Dependent Claim
168 words
In a method of measuring bioelectric potentials across a body comprising the steps of locating at least two electrodes at at least first and second spaced apart locations of a body and electronically subtracting the potentials detected by the electrodes from one another to obtain a signal representative of a desired bioelectric potential across the body with respect to a voltage common point, an improvement comprising the steps of: attaching a current carrying electrode having an electrical lead to a third location on said body, whereby a current flows in said lead developing a voltage drop across an impedance thereof, attaching a voltage measuring electrode to a fourth location on said body, developing a difference potential signal between the voltage in said current carrying conductor and the voltage measuring electrode and adding that measured potential to the potential of said current carrying conductor, thereby to generate a voltage signal substantially the same as a common body voltage, and driving said voltage common point with said combined voltage signal.
Claim 5
Dependent Claim
168 words
In a method of measuring bioelectric potentials across a body comprising the steps of locating at least two electrodes at at least first and second spaced apart locations of a body and electronically subtracting the potentials detected by the electrodes from one another to obtain a signal representative of a desired bioelectric potential across the body with respect to a voltage common point, an improvement comprising the steps of: attaching a current carrying electrode having an electrical lead to a third location on said body, whereby a current flows in said lead developing a voltage drop across an impedance thereof, attaching a voltage measuring electrode to a fourth location on said body, developing a difference potential signal between the voltage in said current carrying conductor and the voltage measuring electrode and adding that measured potential to the potential of said current carrying conductor, thereby to generate a voltage signal substantially the same as a common body voltage, and driving said voltage common point with said combined voltage signal.
Claim 6
Independent Claim
82 words
A method of developing a voltage signal that is proportional to electrostatic voltage variations on a body for use in noise compensation, comprising the steps of: attaching a first electrode to said body and electrically connecting the first electrode with an amplifier common, and attaching a second electrode to said body and electrically connecting it to a high impedance input of an amplifier that shares said amplifier common, whereby an amplifier output developes said voltage signal proportional to body surface voltage changes.
Claim 7
Independent Claim
82 words
A method of developing a voltage signal that is proportional to electrostatic voltage variations on a body for use in noise compensation, comprising the steps of: attaching a first electrode to said body and electrically connecting the first electrode with an amplifier common, and attaching a second electrode to said body and electrically connecting it to a high impedance input of an amplifier that shares said amplifier common, whereby an amplifier output developes said voltage signal proportional to body surface voltage changes.
Claim 8
Dependent Claim
154 words
Apparatus for developing a signal proportional bioelectric potential across a body, comprising: a high input impedance instrument amplifier having at least two inputs, a common reference point and an output delivering a voltage proportional to the difference in voltage level at said inputs with respect to said common point, means for electrically connecting two independent potential detecting electrodes to each of the said at least two amplifier inputs, whereby electrodes so connected may be electrically connected to said body for developing said signal proportional to the biooelectric signal across said body at said instrument amplifier output, a second amplifier having inverting and non-inverting inputs and an output connected to drive said amplifier common point with a voltage with respect to a common point of the second amplifier, said inverting input being coupled to its output, and means for connecting two additional electrodes to said second amplifier non-inverting input and said second amplifier common point.
Claim 9
Dependent Claim
154 words
Apparatus for developing a signal proportional bioelectric potential across a body, comprising: a high input impedance instrument amplifier having at least two inputs, a common reference point and an output delivering a voltage proportional to the difference in voltage level at said inputs with respect to said common point, means for electrically connecting two independent potential detecting electrodes to each of the said at least two amplifier inputs, whereby electrodes so connected may be electrically connected to said body for developing said signal proportional to the biooelectric signal across said body at said instrument amplifier output, a second amplifier having inverting and non-inverting inputs and an output connected to drive said amplifier common point with a voltage with respect to a common point of the second amplifier, said inverting input being coupled to its output, and means for connecting two additional electrodes to said second amplifier non-inverting input and said second amplifier common point.
Claim 10
Dependent Claim
40 words
Apparatus according to claim 5 wherein said means for connecting an electrode to said second amplifier non-inverting input includes a shield therearound which is electrically connected with said second amplifier output, whereby substantially no current flows in this electrode conductor.
Claim 11
Dependent Claim
39 words
Apparatus according to claim 5 which additionally includes a display means and electrically isolated means for coupling said instrument amplifier output signal to said display means, whereby the equipment is isolated from any ground potential of said display means.
Claim 12
Dependent Claim
126 words
In a method of measuring a bioelectric potential of a body comprising the steps of contacting an electrode against said body and electronically developing from said electrode a voltage signal with respect to a common point that is proportional to said bioelectric potential for monitoring the body bioelectric potential, a method of driving the voltage of said common point to follow voltages induced in said body, comprising the steps of: attaching a current carrying electrode to said body and electrically connecting the current electrode with an amplifier common, attaching a voltage measuring electrode to said body and electrically connecting said voltage electrode to a high impedance input of an amplifier that shares said amplifier common, and driving said common point with an output of said amplifier.
Claim 13
Dependent Claim
126 words
In a method of measuring a bioelectric potential of a body comprising the steps of contacting an electrode against said body and electronically developing from said electrode a voltage signal with respect to a common point that is proportional to said bioelectric potential for monitoring the body bioelectric potential, a method of driving the voltage of said common point to follow voltages induced in said body, comprising the steps of: attaching a current carrying electrode to said body and electrically connecting the current electrode with an amplifier common, attaching a voltage measuring electrode to said body and electrically connecting said voltage electrode to a high impedance input of an amplifier that shares said amplifier common, and driving said common point with an output of said amplifier.
Claim 14
Dependent Claim
119 words
In an instrument having electronic means with at least one input for connection to a body contacting electrode and an output for developing a voltage with respect to a common point that is proportional to a bioelectric potential of said body, the improvement of means for controlling the voltage of said common point, comprising: an amplifier having inverting and non-inverting inputs and an output connected to drive said common point with a voltage with respect to a common of the amplifier, said inverting input being coupled directly to said amplifier output, means for electrically connecting a body contacting current carrying electrode to said amplifier common, and means for electrically connecting a body contacting voltage electrode to said non-inverting input.
Claim 15
Dependent Claim
119 words
In an instrument having electronic means with at least one input for connection to a body contacting electrode and an output for developing a voltage with respect to a common point that is proportional to a bioelectric potential of said body, the improvement of means for controlling the voltage of said common point, comprising: an amplifier having inverting and non-inverting inputs and an output connected to drive said common point with a voltage with respect to a common of the amplifier, said inverting input being coupled directly to said amplifier output, means for electrically connecting a body contacting current carrying electrode to said amplifier common, and means for electrically connecting a body contacting voltage electrode to said non-inverting input.
Claim 16
Dependent Claim
33 words
The improved instrument of claim 9 wherein said means for electrically connecting a body contacting voltage electrode to said non-inverting input includes a shield therearound which is electrically connected to said amplifier output.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |