US3890957A
Expired / Lapsed
US
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Biological feedback systems
Assignee: FSW ASSOCIATES
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Filing: 1974-08-02
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Granted: 1975-06-24
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Expires: 1994-08-02
Abstract
Abstract A biological feedback system which is particularly useful for the processing of EEG (electroencephalogram) signals. In such use the present system receives a signal from a subject organism and generates an electrical signal in response thereto. Provision is made for detecting the dominant periodicity of this electrical signal, preferably as the time average of zero crossings of the signal about its own average value. A first analog signal is developed having a DC magnitude which is proportional to the frequency of the periodicity. A hybrid filter is used to develop the first signal by analog to digital conversion, counting and averaging the zero crossings and reconverting the average count in analog form. A second analog signal is developed, the DC magnitude of which is proportional to the strength of the signal received from the subject. These first and second analog signals are used to control the output of various indicators having signals which are perceptible to the subject to thereby complete a feedback loop. In a preferred form of the invention these analog signals are used to control the output of a noise source so as to vary the spectral content of the noise source between high and low values in response to a change of the frequency of the signal from the subject. The range of emissions from the noise source is selected to be audible to the subject when converted to sound waves. The strength of the noise emission is controlled by the strength of the second analog signal and is accordingly proportional to the strength of the signal received.
Inventors
- 👤 James A Freeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:04
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/369; A61B5/375; A61B5/372
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
147 words
In a bio-feedback device or system for processing a biogenerated signal produced by human or animal organism, means for generating an electrical signal in response to a bio-generated signal, means for detecting the dominant frequency of said electrical signal, means for discriminating against subdominant frequenices and noise contained in said signal, said means comprising means for establishing an inhibit time interval after each detection having a duration slightly less than but approaching the periodicity interval being investigated for controlling the output of said detecting means so that the output thereof is inhibited during said time interval, means for converting said detected dominant frequency to a signal the magnitude of which is proportional to said indicator means for creating a signal which varies between conditions perceptible to said organism, and means responsive to the magnitude of said analog signal for changing the indicated value of said indicator means.
Claim 2
Dependent Claim
147 words
In a bio-feedback device or system for processing a biogenerated signal produced by human or animal organism, means for generating an electrical signal in response to a bio-generated signal, means for detecting the dominant frequency of said electrical signal, means for discriminating against subdominant frequenices and noise contained in said signal, said means comprising means for establishing an inhibit time interval after each detection having a duration slightly less than but approaching the periodicity interval being investigated for controlling the output of said detecting means so that the output thereof is inhibited during said time interval, means for converting said detected dominant frequency to a signal the magnitude of which is proportional to said indicator means for creating a signal which varies between conditions perceptible to said organism, and means responsive to the magnitude of said analog signal for changing the indicated value of said indicator means.
Claim 3
Dependent Claim
34 words
A bio-feedback device as in claim 1 in which said means for converting the detected dominant frequency produces a voltage, the magnitude of which is linearly proportional to the time averaged dominant frequency thereof.
Claim 4
Dependent Claim
187 words
In a bio-feedback system for processing a bio-generated signal produced by a human or animal organism, means for generating an electrical signal in response to the bio-generated signal, means for detecting the dominant frequency of said electrical signal, means for developing an analog signal the DC magnitude of which is proportional to said dominant frequency, means for detecting the average strength of said bio-generated signal, means for converting the same into a second analog signal the DC magnitude of which is proportional to the strength of said bio-generated signal, means for producing noise signals over a frequency range audible to said human or animal organism when converted to sound waves, means responsive to the output off one of said analog signals for varying the spectral content of said noise signals from a high range to a low range as the DC magnitude of said one signal varies between high and low values, means responsive to the other of said analog signals for varying the strength of said noise signal in response thereto, and means for accepting said noise signal and for converting the same into sound waves.
Claim 5
Dependent Claim
187 words
In a bio-feedback system for processing a bio-generated signal produced by a human or animal organism, means for generating an electrical signal in response to the bio-generated signal, means for detecting the dominant frequency of said electrical signal, means for developing an analog signal the DC magnitude of which is proportional to said dominant frequency, means for detecting the average strength of said bio-generated signal, means for converting the same into a second analog signal the DC magnitude of which is proportional to the strength of said bio-generated signal, means for producing noise signals over a frequency range audible to said human or animal organism when converted to sound waves, means responsive to the output off one of said analog signals for varying the spectral content of said noise signals from a high range to a low range as the DC magnitude of said one signal varies between high and low values, means responsive to the other of said analog signals for varying the strength of said noise signal in response thereto, and means for accepting said noise signal and for converting the same into sound waves.
Claim 6
Dependent Claim
28 words
A bio-feedback system as in claim 3 further including means for blanking the output signal whenever the magnitude of said first analog signal exceeds a first threshold value.
Claim 7
Dependent Claim
29 words
A bio-feedback system as in claim 3 further including means for blanking the output signal wheneveR the magnitude of said first analog signal is less than a predetermined value.
Claim 8
Dependent Claim
31 words
A bio-feedback system as in claim 3 further including means responsive to the second analog signal for blanking the same whenever said second analog signal is less than a predetermined value.
Claim 9
Dependent Claim
26 words
A bio-feedback system as in claim 3 further including visual indicator means for developing a perceptible reading indicative of the magnitude of said first analog signal.
Claim 10
Dependent Claim
48 words
A bio-feedback system as in claim 3 wherein said noise source includes means for generating a substantially wide band noise signal and wherein said means responsive to the output of said analog signal includes selection means selective for transmitting a limited and variable portion of the noise signal.
Claim 11
Dependent Claim
57 words
A bio-feedback system as in claim 3 in which said means for varying the spectral content of the output of said output noise signal is responsive to the strength of said first analog signal, and in which the means for varying the amplitude of the ouput of said noise signal is responsive to said second analog signal.
Claim 12
Dependent Claim
209 words
In a bio-feedback system for producing the bio-generated signal produced by a subject said bio-generated signal having a dominant frequency characteristic which is desired to detect in the presence of subdominant frequency and noise signals which it is desired to reject, a dominant frequency analyzer comprising means for receiving and generating an electrical signal in correspondence to said bio-generated signal, means for referencing said signal about a predetermined level so that said signal crosses said level in accordance with said periodicity to define a level crossing each occasion thereof, means for detecting said crossings of said signal and for developing a digital output signal for each detected level crossing, means for establishing an inhibit time interval after each level crossing having a duration slightly less than but approaching the periodicity interval being investigated and for controlling the output of said detecting means so that the output thereof is inhibited during said time interval, means for receiving said digital output signal and for developing a voltage proportional to the frequency of said zero crossing, said last named means including means for averaging said proportional voltage over a number of zero crossing intervals, indicator means responsive to said average proportional voltage for creating a signal which is perceptible to said organism.
Claim 13
Dependent Claim
209 words
In a bio-feedback system for producing the bio-generated signal produced by a subject said bio-generated signal having a dominant frequency characteristic which is desired to detect in the presence of subdominant frequency and noise signals which it is desired to reject, a dominant frequency analyzer comprising means for receiving and generating an electrical signal in correspondence to said bio-generated signal, means for referencing said signal about a predetermined level so that said signal crosses said level in accordance with said periodicity to define a level crossing each occasion thereof, means for detecting said crossings of said signal and for developing a digital output signal for each detected level crossing, means for establishing an inhibit time interval after each level crossing having a duration slightly less than but approaching the periodicity interval being investigated and for controlling the output of said detecting means so that the output thereof is inhibited during said time interval, means for receiving said digital output signal and for developing a voltage proportional to the frequency of said zero crossing, said last named means including means for averaging said proportional voltage over a number of zero crossing intervals, indicator means responsive to said average proportional voltage for creating a signal which is perceptible to said organism.
Claim 14
Dependent Claim
44 words
A bio-feedback system as in claim 10 further including continuously variable voltage comparator means for comparing the analog output voltage of said analyzer with predetermined reference voltages and for blanking said output whenever its value is less than or greater than predetermined values thereof.
Claim 15
Dependent Claim
233 words
A bio-feedback system responsive to detectable signals generated by a subject that are representative of the biological state, said system comprising means connected to said subject for detecting said signals and for generating an electrical signal having the characteristics of said signals, amplitude detector means responsive to the detected signals for developing an amplitude voltage signal proportional to the amplitude thereof, pulse generator means responsive to the detected signals for generating a train of pulses having a pulse frequency proportional to the dominant frequency of the detected signal, coverter means responsive to the generated pulse train for producing a voltage signal proportional to the pulse frequency of the generated pulse train, voltage level sensing circuit means responsive to the pulse frequency proportional voltage signal for producing a frequency control signal whenever said frequency voltage signal lies within a predetermined range of values, comparator circuit means responsive to the amplitude signal for producing an amplitude control signal whenever said amplitude exceeds a predetermined value, gate means responsive to thE frequency and amplitude control signals having an on state whenever both of said control signals are present, means responsive to said state of said gate for developing a subject perceptible feedback noise signal having a frequency content moveable in direct proportion to the frequency of said biological signal and an amplitude variable in direct proportion to variations in the average strength of said biological signal.
Claim 16
Dependent Claim
233 words
A bio-feedback system responsive to detectable signals generated by a subject that are representative of the biological state, said system comprising means connected to said subject for detecting said signals and for generating an electrical signal having the characteristics of said signals, amplitude detector means responsive to the detected signals for developing an amplitude voltage signal proportional to the amplitude thereof, pulse generator means responsive to the detected signals for generating a train of pulses having a pulse frequency proportional to the dominant frequency of the detected signal, coverter means responsive to the generated pulse train for producing a voltage signal proportional to the pulse frequency of the generated pulse train, voltage level sensing circuit means responsive to the pulse frequency proportional voltage signal for producing a frequency control signal whenever said frequency voltage signal lies within a predetermined range of values, comparator circuit means responsive to the amplitude signal for producing an amplitude control signal whenever said amplitude exceeds a predetermined value, gate means responsive to thE frequency and amplitude control signals having an on state whenever both of said control signals are present, means responsive to said state of said gate for developing a subject perceptible feedback noise signal having a frequency content moveable in direct proportion to the frequency of said biological signal and an amplitude variable in direct proportion to variations in the average strength of said biological signal.
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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |