US3710792A — Doppler shift ultrasonic vascular flowmeter emplo…

Claim 1

Independent Claim 228 words

A transcutaneous Doppler flowmeter for measuring blood flow comprising: a transducer assembly including a pair of juxtaposed piezoelectric crystals, a generator means connected to one of said crystals for producing an ultrasonic frequency alternating voltage to cause said one crystal to radiate an ultrasound wave therefrom, a mixer means connected to said generator and the other of said crystals for heterodyning said alternating voltage from said generator with alternating voltages from said other crystal generated by the reception thereat of reflected ultrasound waves from said one crystal, and thereby to produce at an output a Doppler shift signal, a plurality of narrow bandpass filters spanning respectively successive frequency bands within a predetermined frequency range, and connected in parallel to said output of said mixer for providing at an output of said filters respective Doppler shift frequency band signals, circuit means connected to the output of each of said filters for each providing an output signal representing the power of said Doppler shift frequency band signals, and display means connected to said circuit means for receiving said output signals and for producing a real-time, two-co-ordinate, effectively three-dimensional visual display representing in one co-ordinate direction the Doppler shift frequency progressions of input signals thereto, in the other co-ordinate the time progression of input signals thereto, and as effective spectral density variations the power of the Doppler shift frequency band signals.

Claim 2

Dependent Claim 228 words

A transcutaneous Doppler flowmeter for measuring blood flow comprising: a transducer assembly including a pair of juxtaposed piezoelectric crystals, a generator means connected to one of said crystals for producing an ultrasonic frequency alternating voltage to cause said one crystal to radiate an ultrasound wave therefrom, a mixer means connected to said generator and the other of said crystals for heterodyning said alternating voltage from said generator with alternating voltages from said other crystal generated by the reception thereat of reflected ultrasound waves from said one crystal, and thereby to produce at an output a Doppler shift signal, a plurality of narrow bandpass filters spanning respectively successive frequency bands within a predetermined frequency range, and connected in parallel to said output of said mixer for providing at an output of said filters respective Doppler shift frequency band signals, circuit means connected to the output of each of said filters for each providing an output signal representing the power of said Doppler shift frequency band signals, and display means connected to said circuit means for receiving said output signals and for producing a real-time, two-co-ordinate, effectively three-dimensional visual display representing in one co-ordinate direction the Doppler shift frequency progressions of input signals thereto, in the other co-ordinate the time progression of input signals thereto, and as effective spectral density variations the power of the Doppler shift frequency band signals.

Claim 3

Dependent Claim 23 words

A flowmeter according to claim 1 further including amplifier means connected between said mixer and said filters for amplifying said Doppler shift signal.

Claim 4

Dependent Claim 97 words

A flowmeter according to claim 1 wherein said display means comprises: a plurality of first electrodes of one polarity arranged in a mutually spaced array along said one co-ordinate direction; a terminal respectively conneCting said circuit means with said first electrode; consumable second electrode means of opposite polarity to said first electrode locatable closely adjacent said first electrodes to span the same along said one co-ordinate direction; and a strip of electro-sensitive, paper-like record medium mounted for movement in said other co-ordinate direction between and in engagement with both said first electrodes and said second electrode means.

Claim 5

Dependent Claim 33 words

A flowmeter according to claim 3 wherein said second electrode means comprises a single strip-form electrode and means for driving said strip-form electrode longitudinally with one edge thereof passing nearest said first electrodes.

Claim 6

Dependent Claim 16 words

A flowmeter according to claim 4 wherein said single strip-form electrode is of closed loop form.

Claim 7

Dependent Claim 39 words

A flowmeter according to claim 3 wherein said first electrodes comprise a plurality of parallel strips of conductive material supported in a common body of flexible electrically insulating material and exposed in a transverse portion to form said array.

Claim 8

Dependent Claim 101 words

A transcutaneous Doppler flowmeter comprising: means for producing an ultrasonic wave and for applying said wave to an exterior body location so that said wave propagates into the body and is reflected with a Doppler shift reflecting the velocity of flow within a vascular channel, means for receiving the reflected ultrasonic wave and producing an electrical signal having a characteristic which varies as a function of the received energy at each of a plurality of discrete frequency ranges, and recording means for receiving said electrical signal simultaneously and producing a record indicating the received energy at each of said discrete ranges.

Claim 9

Dependent Claim 101 words

A transcutaneous Doppler flowmeter comprising: means for producing an ultrasonic wave and for applying said wave to an exterior body location so that said wave propagates into the body and is reflected with a Doppler shift reflecting the velocity of flow within a vascular channel, means for receiving the reflected ultrasonic wave and producing an electrical signal having a characteristic which varies as a function of the received energy at each of a plurality of discrete frequency ranges, and recording means for receiving said electrical signal simultaneously and producing a record indicating the received energy at each of said discrete ranges.

Claim 10

Dependent Claim 61 words

A flowmeter as in claim 7 wherein said producing means includes ultrasonic transducer for a transcutaneous Doppler flowmeter comprising: means for housing an ultrasonic wave transmitting liquid, and having a telescoping extending nozzle, means within said housing for producing an ultrasonic wave, and means mounted on the end of said nozzle adapted for coupling said ultrasonic wave to a body portion.

Claim 11

Dependent Claim 18 words

A flowmeter as in claim 8 wherein said housing means includes a hollow bellows defining said telescoping nozzle.

Claim 12

Dependent Claim 19 words

A flowmeter as in claim 8 wherein said coupling means includes a diaphragm sealing said end of said nozzle.

Claim 13

Dependent Claim 22 words

A flowmeter as in claim 8 wherein said transducer further includes means defining a passage through said housing for adding liquid thereto.

Claim 14

Dependent Claim 15 words

A flowmeter as in claim 8 wherein said producing means includes first and second transducers.

Claim 15

Dependent Claim 30 words

A flowmeter as in claim 8 wherein said transducer further includes means lining the interior of said housing means for absorbing radiation from said ultrasonic wave producing and applying means.

Claim 16

Dependent Claim 19 words

A flowmeter as in claim 8 wherein said receiving and electrical signal producing means includes a plurality of filters.

Claim 17

Dependent Claim 122 words

A flowmeter as in claim 8 wherein said recording means includes: a plurality of electrodes of a first polarity disposed in a spaced array and connected to said receiving and electric signal producing means so that each said electrode has applied to it a potential which varies as a function of the received energy in one of said frequency ranges, second electrode means disposed adjacent said plurality of electrodes so as to define a plurality of matrix locations each associated with one of said frequency ranges, and means mounting a record medium for movement between said first plurality of electrodes and said second electrodes and said second electrode means for producing said record indicating the energy at each of said discrete ranges.

Claim 18

Dependent Claim 21 words

A flowmeter as in claim 15 wherein said second electrode means includes a closed loop of a single strip-form consumable electrode.

Claim 19

Dependent Claim 20 words

A flowmeter as in claim 15 wherein said plurality of electrodes comprise a plurality of parallel strips of conductive material.

Claim 20

Dependent Claim 46 words

A flowmeter as in claim 15 wherein said Receiving and electric signal producing means includes: means for producing an ultrasonic alternating voltage, means for mixing said ultrasonic alternating voltage, a plurality of narrow band pass filters, and means for applying the mixed signal to said filters.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-01-16	1976-07-17	1977-01-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-01-16	1980-07-17	1981-01-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-01-16	1984-07-17	1985-01-16	$7700.00	Window Closed / Lapsed

Doppler shift ultrasonic vascular flowmeter employing energy content of reflected wave

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