Patent US3835839A successfully refreshed from Google Patents.
US3835839A
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Impedance plethysmograph and flow rate computer adjunct and method for use therewith
Assignee: NEW SD Inc A CORP OF
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Filing: 1972-12-08
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Granted: 1974-09-17
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Expires: 1992-12-08
Abstract
Abstract A computer adjunct for use with an impedance plethysmograph which provides signals related to impedance in a biological segment. Circuit means are included for converting the pulsatile plethysmograph signals to average DC levels and for combining them to provide a signal related to blood hydraulic-flow rate through the biological segment. An adjustable amplifier is provided within the computer for interposing a signal having a predetermined value for providing a normalized signal related to flow rate per volumetric unit of the biological segment. The combination is capable of such measurements for calf segments or thoracic segments.
Inventors
- 👤 L Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:30
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/026; A61B5/0295; A61B5/72; A61B5/7235; A61B5/7239
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
141 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph of the type having current and voltage electrodes adapted to be applied to a biological segment to provide output measurements which may include a signal representing tissue condutance of said segment, a signal representing deviation from the basic resistance of said segment, and a signal representing the rate of change of said deviation, said adjunct comprising means for averaging said deviation signal, means for averaging said rate of change of deviation signal, means for obtaining a product of said average signals, means for multiplying said product by a signal with magnitude determined by biological segment electrical chaRacteristics and electrode placement, and means for multiplying said last named product by said tissue conductance signal whereby an output signal is obtained which is related to a volumetric blood flow rate through said biological segment.
Claim 2
Dependent Claim
141 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph of the type having current and voltage electrodes adapted to be applied to a biological segment to provide output measurements which may include a signal representing tissue condutance of said segment, a signal representing deviation from the basic resistance of said segment, and a signal representing the rate of change of said deviation, said adjunct comprising means for averaging said deviation signal, means for averaging said rate of change of deviation signal, means for obtaining a product of said average signals, means for multiplying said product by a signal with magnitude determined by biological segment electrical chaRacteristics and electrode placement, and means for multiplying said last named product by said tissue conductance signal whereby an output signal is obtained which is related to a volumetric blood flow rate through said biological segment.
Claim 3
Dependent Claim
64 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph as in claim 1 wherein said means for averaging said deviation signal includes a DC restorer for receiving said signal proportional to deviation and for producing a pulsating DC voltage with zero bias, and a resistive-capacitive averaging circuit for receiving said pulsating DC voltage and producing a DC voltage level proportional to said deviation average.
Claim 4
Dependent Claim
105 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph as in claim 1 wherein said signal representing the rate of change of said deviation is in the form of pulses synchronous with the pulse rate of the heart which supplies blood to said biological segment and said means for averaging said rate of change of deviation signal comprises a one shot multivibrator for receiving said signal representing rate of change of deviation and for producing a square wave output pulse for each input pulse, and a resistive-capacitive averaging circuit for receiving said square wave output and producing a DC voltage level proportional to heart rate.
Claim 5
Dependent Claim
38 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph as in claim 1 together with means for adjusting said signal proportional to tissue conductance to introduce bias and scale factor correction prior to obtaining said last named product.
Claim 6
Dependent Claim
38 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph as in claim 1 together with scale factor amplifier means, and flow rate meter means for providing flow rate indication in desired units of volume per increment of time.
Claim 7
Dependent Claim
42 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph as in claim 1 together with fixed value multiplier means, and flow rate meter means for providing normalized flow rate indication in flow rate per volumetric unit of tissue in said biological segment.
Claim 8
Dependent Claim
113 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph of the type having current and voltage electrodes adapted to be applied to a thoracic segment to provide output measurements which may include a signal representing deviation from the basic resistance of said segment, and a signal representing the rate of change of said deviation, comprising means for averaging said deviation signal, means for averaging said rate of change of deviation signal, means for obtaining a product of said average signals, and means for multiplying said product by a constant determined by the volumetric unit of thoracic segment for providing an output signal related to flow rate per volmetric unit of said thoracic segment.
Claim 9
Dependent Claim
113 words
A Flow Rate Computer Adjunct for an Impedance Plethysmograph of the type having current and voltage electrodes adapted to be applied to a thoracic segment to provide output measurements which may include a signal representing deviation from the basic resistance of said segment, and a signal representing the rate of change of said deviation, comprising means for averaging said deviation signal, means for averaging said rate of change of deviation signal, means for obtaining a product of said average signals, and means for multiplying said product by a constant determined by the volumetric unit of thoracic segment for providing an output signal related to flow rate per volmetric unit of said thoracic segment.
Claim 10
Dependent Claim
165 words
In the combination of an impedance plethysmograph and computer adjunct said impedance plethysmograph including a first current and voltage electrode pair; a second current and voltage electrode pair, said first and second electrode pairs being adapted to be applied to a biological segment experiencing pulsating blood flow, said plethysmograph providing output signals related to the conductance of said biological segment, related to the deviation during said pulsatile flow from the basic resistance of said segment, and related to the rate of change of said deviation said computer adjunct comprising means for averaging said deviation signal; means for averaging said rate of change of deviation; means for obtaining a product of said average signals; means for multiplying said product by a signal having a magnitude determined by biological segment electrical characteristics and electrode pair placement; and means for multiplying said last named product by said tissue conductance signal to provide an output signal which is related to the volumetric blood flow rate through said biological segment.
Claim 11
Dependent Claim
165 words
In the combination of an impedance plethysmograph and computer adjunct said impedance plethysmograph including a first current and voltage electrode pair; a second current and voltage electrode pair, said first and second electrode pairs being adapted to be applied to a biological segment experiencing pulsating blood flow, said plethysmograph providing output signals related to the conductance of said biological segment, related to the deviation during said pulsatile flow from the basic resistance of said segment, and related to the rate of change of said deviation said computer adjunct comprising means for averaging said deviation signal; means for averaging said rate of change of deviation; means for obtaining a product of said average signals; means for multiplying said product by a signal having a magnitude determined by biological segment electrical characteristics and electrode pair placement; and means for multiplying said last named product by said tissue conductance signal to provide an output signal which is related to the volumetric blood flow rate through said biological segment.
Claim 12
Independent Claim
164 words
The method of determining the hydraulic flow rate of body fluids thrOugh a biological segment comprising the steps of applying a first current and voltage electrode pair and a second current and voltage electrode pair at opposite ends of said biological segment; connecting said first and second current and voltage electrode pairs to an impedance plethysmograph; generating signals in the plethysmograph related to deviation from the basic resistance of said biological segment, to time derivative of said deviation, and to tissue conductance within said biological segment; averaging said deviation signal; averaging said time derivative signal; multiplying said deviation average signal by said time derivative average signal to provide a product signal; multiplying said product signal by said tissue conductance signal and by a factor which is determined by the electrical characteristics of said biological segment and the placement of said first and second electrode pairs; whereby an output signal indicative of hydraulic flow volume through said biological segment per unit of time is obtained.
Claim 13
Independent Claim
164 words
The method of determining the hydraulic flow rate of body fluids thrOugh a biological segment comprising the steps of applying a first current and voltage electrode pair and a second current and voltage electrode pair at opposite ends of said biological segment; connecting said first and second current and voltage electrode pairs to an impedance plethysmograph; generating signals in the plethysmograph related to deviation from the basic resistance of said biological segment, to time derivative of said deviation, and to tissue conductance within said biological segment; averaging said deviation signal; averaging said time derivative signal; multiplying said deviation average signal by said time derivative average signal to provide a product signal; multiplying said product signal by said tissue conductance signal and by a factor which is determined by the electrical characteristics of said biological segment and the placement of said first and second electrode pairs; whereby an output signal indicative of hydraulic flow volume through said biological segment per unit of time is obtained.
Claim 14
Independent Claim
125 words
The method of determining the hydraulic flow rate of body fluids through a thoracic segment comprising the steps of applying a first current and voltage electrode pair and a second current and voltage electrode pair at opposite ends of said thoracic segment; connecting said first and second current and voltage electrode pairs to an impedance plethysmograph; generating signals in the plethysmograph related to deviation from the basic resistance, related to time derivative of said deviation, and related to tissue conductance within said segment, averaging said deviation signal; averaging said time derivative signal; and multiplying said deviation average signal by said time derivative average signal; for producing an output signal indicative of hydraulic flow rate through said thoracic segment per volumetric unit of said thoracic segment.
Claim 15
Independent Claim
125 words
The method of determining the hydraulic flow rate of body fluids through a thoracic segment comprising the steps of applying a first current and voltage electrode pair and a second current and voltage electrode pair at opposite ends of said thoracic segment; connecting said first and second current and voltage electrode pairs to an impedance plethysmograph; generating signals in the plethysmograph related to deviation from the basic resistance, related to time derivative of said deviation, and related to tissue conductance within said segment, averaging said deviation signal; averaging said time derivative signal; and multiplying said deviation average signal by said time derivative average signal; for producing an output signal indicative of hydraulic flow rate through said thoracic segment per volumetric unit of said thoracic segment.
Claim 16
Independent Claim
136 words
The method of determining blood flow rate through a biological segment utilizing signals proportional to deviation from the basic segment resistance, the time derivative of said deviation, and the tissue conductance of said segment, comprising the steps of obtaining said signals from an impedance plethysmograph, averaging said deviation signal; averaging said time derivative signal; multiplying said deviation average signal by said time derivative average signal; multiplying said last named product by said tissue conductance signal thereby obtaining a signal related to hydraulic flow through said segment; and introducing a factor to said signal related to hydraulic flow, which is determined by the electrical characteristics of said biological segment and the placement of said first and second electrode pairs for producing an output signal indicative of hydraulic flow volume through said biological segment per unit of time.
Claim 17
Independent Claim
136 words
The method of determining blood flow rate through a biological segment utilizing signals proportional to deviation from the basic segment resistance, the time derivative of said deviation, and the tissue conductance of said segment, comprising the steps of obtaining said signals from an impedance plethysmograph, averaging said deviation signal; averaging said time derivative signal; multiplying said deviation average signal by said time derivative average signal; multiplying said last named product by said tissue conductance signal thereby obtaining a signal related to hydraulic flow through said segment; and introducing a factor to said signal related to hydraulic flow, which is determined by the electrical characteristics of said biological segment and the placement of said first and second electrode pairs for producing an output signal indicative of hydraulic flow volume through said biological segment per unit of time.
Claim 18
Independent Claim
148 words
The method of determining the hydraulic flow rate of body fluids through a biological segment supplied with blood by a pulsing rate of the heart comprising the steps of applying a first current and voltage electrode pair and a second current and voltage electrode pair at opposite ends of the biological segment, connecting the first and second current and voltage electrode pairs to an impedance plethysmograph; generating signals in the plethysmograph related to deviation from the basic resistance of the biological segment, related to heart pulsing rate, and related to tissue conductance within the biological segment; averaging said deviation signal and said heart rate signal; multiplying the averaged deviation signal by the averaged heart rate signal to provide a product signal; and multiplying the product signal by tissue conductance signal for producing an output signal indicative of hydraulic flow volume through the biological segment per unit of time.
Claim 19
Independent Claim
148 words
The method of determining the hydraulic flow rate of body fluids through a biological segment supplied with blood by a pulsing rate of the heart comprising the steps of applying a first current and voltage electrode pair and a second current and voltage electrode pair at opposite ends of the biological segment, connecting the first and second current and voltage electrode pairs to an impedance plethysmograph; generating signals in the plethysmograph related to deviation from the basic resistance of the biological segment, related to heart pulsing rate, and related to tissue conductance within the biological segment; averaging said deviation signal and said heart rate signal; multiplying the averaged deviation signal by the averaged heart rate signal to provide a product signal; and multiplying the product signal by tissue conductance signal for producing an output signal indicative of hydraulic flow volume through the biological segment per unit of time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |