US4751471A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifying circuit particularly adapted for amplifying a biopotential input signal
Assignee: Technology 21 Inc
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Filing: 1986-12-23
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Granted: 1988-06-14
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Expires: 2006-12-23
Abstract
Abstract An amplifying circuit for amplifying a bipotential input signal, including an insulating housing having a conductive input contact mounted on the housing and adapted to engage a human body so that the bipotential input signal applied to the contact; a lead amplifier having inverting and non-inverting inputs, one of which is coupled to the input contact, and an output; first and second diodes connected in parallel inverse polarity across the inputs of the lead amplifier; third and fourth diodes connected in parallel inverse polarity from the inverting input of the lead amplifier to a circuit common potential; and an output resistor connected from the inverting input to the output of the lead amplifier. Portions of the input contact are surrounded by a voltage drive shield connected to the output of the lead amplifier.
Inventors
- 👤 W. J. Ross Dunseath, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:26
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/30; A61B2562/00; A61B2562/18; A61B2562/182; Y; Y10; Y10S; Y10S128/00; Y10S128/902
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
145 words
An amplifying circuit for amplifying an input signal from a source, comprising: an insulating housing having a conductive input contact mounted thereon and adapted to engage said source with said input signal applied to said contact; a lead amplifier having an input coupled to said input contact and an output; and a voltage driven first shield connected to said output of said lead amplifier and surrounding portions of said input contact not in engagement with said source; wherein said lead amplifier circuit comprises: an operational amplifier having inverting and non-inverting inputs, first and second diodes connected in parallel inverse polarity across the inputs of said operational amplifer, third and fourth diodes connected in parallel inverse polarity from the inverting input of said operational amplifier to a circuit common potential, and an output resistor connected from the inverting input to the output of said operational amplifier.
Claim 2
Dependent Claim
145 words
An amplifying circuit for amplifying an input signal from a source, comprising: an insulating housing having a conductive input contact mounted thereon and adapted to engage said source with said input signal applied to said contact; a lead amplifier having an input coupled to said input contact and an output; and a voltage driven first shield connected to said output of said lead amplifier and surrounding portions of said input contact not in engagement with said source; wherein said lead amplifier circuit comprises: an operational amplifier having inverting and non-inverting inputs, first and second diodes connected in parallel inverse polarity across the inputs of said operational amplifer, third and fourth diodes connected in parallel inverse polarity from the inverting input of said operational amplifier to a circuit common potential, and an output resistor connected from the inverting input to the output of said operational amplifier.
Claim 3
Dependent Claim
85 words
An amplifying circuit according to claim 1, wherein said lead amplifier circuit further comprises: an input resistor connected between the non-inverting input of said operational amplifier and said conductive input contact, a lead wire cable having plural conductors connected to said operational amplifier and supplying power and circuit common potential current to said operational amplifier and taking out an output from said operational amplifier, and a decoupling resistor connected from the output of said operational amplifier to an output conductor of the lead wire cable.
Claim 4
Dependent Claim
45 words
An amplifying circuit as defined in claim 2, wherein said conductive input contact comprises a material that maintains an AC noise voltage baseline of not more than 150 μV peak (0.15 to 35 Hz) under conditions ranging from dry to saturation with 0.9% saline solution.
Claim 5
Dependent Claim
15 words
An amplifying circuit according to claim 3, wherein said conductive input contact comprises titanium hydride.
Claim 6
Dependent Claim
21 words
An amplifying circuit according to claim 2, wherein said input resistor is at least partially contained within said voltage-driven first shield.
Claim 7
Dependent Claim
69 words
An amplifying circuit according to claim 5, further comprising: a circuit board having opposed sides, wherein on one of said sides of said circuit board said operational amplifier, said first through fourth diodes, and said output and decoupling resistors are mounted, said circuit board having an aperture through which said input resistor extends from the one side to the other side on which said conductive input contact is mounted.
Claim 8
Dependent Claim
73 words
An amplifying circuit according to claim 6, wherein said lead wire cable comprises: a flexible insulated multi-conductor cable including a pair of insulated conductors to carry bipolar supply currents to said lead amplifier, an insulated conductor to carry said circuit common potential current to and from said lead amplifier, said output conductor comprising an insulated conductor to carry an output signal from said lead amplifier, and a second shield shielding said insulated conductors.
Claim 9
Dependent Claim
41 words
An amplifying circuit according to claim 7, further comprising: a voltage follower operational amplifier having a non-inverting input connected to the first shield, an inverting input connected to an output of said voltage follower operational amplifier and to said second shield.
Claim 10
Dependent Claim
45 words
An amplifying circuit as defined in claim 8, wherein said conductive input contact comprises a material that maintains an AC noise voltage baseline of not more than 150 μV peak (0.15 to 35 Hz) under conditions ranging from dry to saturation with 0.9% saline solution.
Claim 11
Dependent Claim
15 words
An amplifying circuit according to claim 9, wherein said conductive input contact comprises titanium hydride.
Claim 12
Dependent Claim
23 words
An amplifying circuit according to claim 7, wherein said second shield is connected to said insulated conductor carrying said circuit common potential current.
Claim 13
Dependent Claim
45 words
An amplifying circuit as defined in claim 1, wherein said conductive input contact comprises a material that maintains an AC noise voltage baseline of not more than 150 μV peak (0.15 to 35 Hz) under conditions ranging from dry to saturation with 0.9% saline solution.
Claim 14
Dependent Claim
15 words
An amplifying circuit according to claim 12, wherein said conductive input contact comprises titanium hydride.
Claim 15
Dependent Claim
112 words
An amplifying circuit for amplifying an input signal from a source, comprising: an insulating housing having a conductive input contact mounted on said housing and adapted to engage said source with said input signal applied to said contact; a lead amplifier having inverting and non-inverting inputs, one of which is coupled to said input contact, and an output; first and second diodes connected in parallel inverse polarity across the inputs of said lead amplifier; third and fourth diodes connected in parallel inverse polarity from the inverting input of said lead amplifier to a circuit common potential; and an output resistor connected from the inverting input to the output of said lead amplifier.
Claim 16
Dependent Claim
112 words
An amplifying circuit for amplifying an input signal from a source, comprising: an insulating housing having a conductive input contact mounted on said housing and adapted to engage said source with said input signal applied to said contact; a lead amplifier having inverting and non-inverting inputs, one of which is coupled to said input contact, and an output; first and second diodes connected in parallel inverse polarity across the inputs of said lead amplifier; third and fourth diodes connected in parallel inverse polarity from the inverting input of said lead amplifier to a circuit common potential; and an output resistor connected from the inverting input to the output of said lead amplifier.
Claim 17
Dependent Claim
34 words
An amplifying circuit according to claim 14, comprising: a voltage driven first shield connected to said output of said lead amplifier and surrounding portions of said input contact not in engagement with said source.
Claim 18
Dependent Claim
45 words
An amplifying circuit as defined in claim 15, wherein said conductive input contact comprises a material that maintains an AC noise voltage baseline of not more than 150 μV peak (0.15 to 35 Hz) under conditions ranging from dry to saturation with 0.9% saline solution.
Claim 19
Dependent Claim
15 words
An amplifying circuit according to claim 16, wherein said conductive input contact comprises titanium hydride.
Claim 20
Dependent Claim
45 words
An amplifying circuit as defined in claim 14, wherein said conductive input contact comprises a material that maintains an AC noise voltage baseline of not more than 150 μV peak (0.15 to 35 Hz) under conditions ranging from dry to saturation with 0.9% saline solution.
Claim 21
Dependent Claim
15 words
An amplifying circuit according to claim 18, wherein said conductive input contact comprises titanium hydride.
References Cited (Backward Citations)
US3500823A
Cited
US3565060A
Cited
US3586991A
Cited
US3605728A
Cited
US3628527A
Cited
US3620208A
Cited
US3679989A
Cited
US3744482A
Cited
US3880146A
Cited
SU684713A1
Cited
US4235241A
Cited
US4200109A
Cited
US4243044A
Cited
US4492932A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |