Patent US6544180B1 successfully refreshed from Google Patents.
US6544180B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blood flow meter apparatus and method of use
Assignee: Data Sciences International Inc
•
Filing: 1999-11-30
•
Granted: 2003-04-08
•
Expires: 2019-11-30
Abstract
Abstract A strobed blood flow meter provides periodic measurements of blood flow velocity or volumetric blood flow over a cardiac cycle at reduced average power consumption, which is advantageous for reducing battery size, and extending device battery life, such as in an implantable application. Continuous wave Doppler, pulsed Doppler, laser Doppler, transit time, electromagnetic flow, and thermal dilution techniques are included. Strobing provides higher level excitation during active periods, which improves signal-to-noise ratio, and provides a low power standby mode during an idle time between active periods. The invention may be used for chronic or acute applications. Doppler or other signals may be telemetered from an implanted portion of the flow meter for further signal processing to extract velocity or volumetric flow. Alternatively, such signal processing is also implanted, such that the velocity signal can be telemetered to an remote monitor.
Inventors
- 👤 Gregory P. Doten
- 👤 Brian P. Brockway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:12
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/06; A61B8/12; A61B2560/00; A61B2560/02; A61B2560/0204; A61B2560/0209; A61B5/00; A61B5/0002; A61B5/0031
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
99 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices; and a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a strobing control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the strobing control signal until a subsequent fluid flow estimate is to be obtained.
Claim 2
Independent Claim
99 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices; and a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a strobing control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the strobing control signal until a subsequent fluid flow estimate is to be obtained.
Claim 3
Dependent Claim
44 words
The apparatus of claim 1 , further comprising a source of one or more power control signals applied to the source of the excitation signal such that the source of the excitation signal is reduced for at least a portion of the idle period.
Claim 4
Dependent Claim
19 words
The apparatus of claim 1 , further comprising an implantable housing containing the source of the electrical excitation signal.
Claim 5
Dependent Claim
32 words
The apparatus of claim 3 , further comprising a telemetry device, contained within the housing, for transmitting from the apparatus one or more signals containing information indicative of the fluid flow estimate.
Claim 6
Dependent Claim
40 words
The apparatus of claim 4 , further comprising a source of one or more power control signals applied to the telemetry device such that the telemetry device is powered down or off when not transmitting signals from the implantable apparatus.
Claim 7
Dependent Claim
18 words
The apparatus of claim 1 , wherein the monitoring devices comprise monitoring devices for transit time flow measurement.
Claim 8
Dependent Claim
19 words
The apparatus of claim 1 , wherein the monitoring devices comprise monitoring devices for laser Doppler time flow measurement.
Claim 9
Dependent Claim
17 words
The apparatus of claim 1 , wherein the monitoring devices comprise monitoring devices for electromagnetic flow measurement.
Claim 10
Dependent Claim
18 words
The apparatus of claim 1 , wherein the monitoring devices comprise monitoring devices for thermal dilution flow measurement.
Claim 11
Independent Claim
392 words
An apparatus for obtaining a time-shifted ultrasonic energy signal for repeatedly estimating fluid flow, the apparatus comprising: a control circuit that provides a first and second electrical ultrasonic-frequency signals containing ultrasonic-frequency components during an active period of a control signal that is of sufficient duration to obtain a fluid flow estimate, and contain substantially no ultrasonic-frequency components during at least a portion of an idle period of the control signal between the active period and a subsequent active period; a first amplifier having an amplifier input, which is electrically coupled to the control circuit for receiving the first ultrasonic-frequency signal, and an amplifier output providing a first electrical amplified ultrasonic-frequency signal in response thereto; a second amplifier having an amplifier input, which is electrically coupled to the control circuit for receiving the second ultrasonic-frequency signal, and an amplifier output providing a second electrical amplified ultrasonic-frequency signal in response thereto; a first transducer having a transducer electrical input, which is electrically coupled to the amplifier output of the first amplifier for receiving the first amplified ultrasonic-frequency signal, and having a transducer ultrasound output, for providing a first ultrasonic-frequency signal to the conduit in response to the first amplified ultrasonic-frequency signal, and having a transducer ultrasound input, for receiving a second time-shifted ultrasonic-frequency signal from the conduit, and having a transducer electrical output, for providing a second electrical received time-shifted signal in response thereto; a second transducer having a transducer electrical input, which is electrically coupled to the amplifier output of the second amplifier for receiving the second amplified ultrasonic-frequency signal, and having a transducer ultrasound output, for providing a second ultrasonic-frequency signal to the conduit in response to the second amplified ultrasonic-frequency signal, and having a transducer ultrasound input, for receiving a first time-shifted ultrasonic-frequency signal from the conduit, and having a transducer electrical output, for providing a first electrical received time-shifted signal in response thereto; a first receiver having a receiver input electrically coupled to the first transducer electrical output for receiving the second electrical received time-shifted signal and having a receiver output for providing a first buffered time-shifted signal in response thereto; and a second receiver having a receiver input electrically coupled to the second transducer electrical output for receiving the first electrical received time-shifted signal and having a receiver output for providing a second buffered time-shifted signal in response thereto.
Claim 12
Independent Claim
392 words
An apparatus for obtaining a time-shifted ultrasonic energy signal for repeatedly estimating fluid flow, the apparatus comprising: a control circuit that provides a first and second electrical ultrasonic-frequency signals containing ultrasonic-frequency components during an active period of a control signal that is of sufficient duration to obtain a fluid flow estimate, and contain substantially no ultrasonic-frequency components during at least a portion of an idle period of the control signal between the active period and a subsequent active period; a first amplifier having an amplifier input, which is electrically coupled to the control circuit for receiving the first ultrasonic-frequency signal, and an amplifier output providing a first electrical amplified ultrasonic-frequency signal in response thereto; a second amplifier having an amplifier input, which is electrically coupled to the control circuit for receiving the second ultrasonic-frequency signal, and an amplifier output providing a second electrical amplified ultrasonic-frequency signal in response thereto; a first transducer having a transducer electrical input, which is electrically coupled to the amplifier output of the first amplifier for receiving the first amplified ultrasonic-frequency signal, and having a transducer ultrasound output, for providing a first ultrasonic-frequency signal to the conduit in response to the first amplified ultrasonic-frequency signal, and having a transducer ultrasound input, for receiving a second time-shifted ultrasonic-frequency signal from the conduit, and having a transducer electrical output, for providing a second electrical received time-shifted signal in response thereto; a second transducer having a transducer electrical input, which is electrically coupled to the amplifier output of the second amplifier for receiving the second amplified ultrasonic-frequency signal, and having a transducer ultrasound output, for providing a second ultrasonic-frequency signal to the conduit in response to the second amplified ultrasonic-frequency signal, and having a transducer ultrasound input, for receiving a first time-shifted ultrasonic-frequency signal from the conduit, and having a transducer electrical output, for providing a first electrical received time-shifted signal in response thereto; a first receiver having a receiver input electrically coupled to the first transducer electrical output for receiving the second electrical received time-shifted signal and having a receiver output for providing a first buffered time-shifted signal in response thereto; and a second receiver having a receiver input electrically coupled to the second transducer electrical output for receiving the first electrical received time-shifted signal and having a receiver output for providing a second buffered time-shifted signal in response thereto.
Claim 13
Dependent Claim
141 words
The apparatus of claim 10 , wherein the first ultrasound transducer comprises: a first transmit transducer, which is electrically coupled to the amplifier output of the first amplifier for receiving the first amplified ultrasonic-frequency signal and providing the first ultrasonic-frequency signal to the conduit in response thereto; and a first receive transducer, for receiving the second time-shifted ultrasonic-frequency signal from the conduit and providing the second electrical received time-shifted signal in response thereto, and wherein the second ultrasound transducer comprises: a second transmit transducer, which is electrically coupled to the amplifier output of the second, amplifier for receiving the second amplified ultrasonic-frequency signal and providing the second, ultrasonic-frequency signal to the conduit in response thereto; and a second receive transducer, for receiving the first time-shifted ultrasonic-frequency signal from the conduit and providing the first electrical received time-shifted signal in response thereto.
Claim 14
Dependent Claim
28 words
The apparatus of claim 10 , further comprising a processing circuit for receiving the first and second buffered time-shifted signals and providing a flow signal in response thereto.
Claim 15
Dependent Claim
24 words
The apparatus of claim 12 , further comprising a telemetry circuit coupled to the processing circuit for receiving, and transmitting therefrom, the flow signal.
Claim 16
Dependent Claim
29 words
The apparatus of claim 13 , further comprising a remote telemetry device that is wirelessly coupled to the telemetry circuit for receiving the flow signal that is transmitted therefrom.
Claim 17
Dependent Claim
65 words
The apparatus of claim 10 , further comprising a reflector, wherein the reflector receives the first ultrasonic-frequency signal from the first transducer, through the conduit, and sends the first ultrasonic-frequency signal to the second transducer, through the conduit, and further wherein the reflector receives the second ultrasonic-frequency signal from the second transducer, through the conduit, and sends the second ultrasonic-frequency signal to the first transducer.
Claim 18
Dependent Claim
13 words
The apparatus of claim 15 , wherein the reflector is an acoustic reflector.
Claim 19
Dependent Claim
28 words
The apparatus of claim 15 , further comprising a processing circuit for receiving the first and second buffered time-shifted signals and providing a flow signal in response thereto.
Claim 20
Dependent Claim
24 words
The apparatus of claim 17 , further comprising a telemetry circuit coupled to the processing circuit for receiving, and transmitting therefrom, the flow signal.
Claim 21
Dependent Claim
29 words
The apparatus of claim 18 , further comprising a remote telemetry device that is wirelessly coupled to the telemetry circuit for receiving the flow signal that is transmitted therefrom.
Claim 22
Dependent Claim
24 words
The apparatus of claim 10 , further comprising an impedance matching network series-connected between the amplifier and the transducer for improving power transfer therebetween.
Claim 23
Dependent Claim
47 words
The apparatus of claim 10 , wherein the first ultrasonic-frequency signal has a directional component in the same direction as the fluid flow in the conduit and wherein the second ultrasonic-frequency signal has a directional component in the opposite direction as the fluid flow in the conduit.
Claim 24
Independent Claim
108 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices; a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the control signal until a subsequent fluid flow estimate is to be obtained; and an implantable housing containing the source of the electrical excitation signal.
Claim 25
Independent Claim
108 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices; a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the control signal until a subsequent fluid flow estimate is to be obtained; and an implantable housing containing the source of the electrical excitation signal.
Claim 26
Dependent Claim
32 words
The apparatus of claim 22 , further comprising a telemetry device, contained within the housing, for transmitting from the apparatus one or more signals containing information indicative of the fluid flow estimate.
Claim 27
Dependent Claim
40 words
The apparatus of claim 23 , further comprising a source of one or more power control signals applied to the telemetry device such that the telemetry device is powered down or off when not transmitting signals from the implantable apparatus.
Claim 28
Independent Claim
108 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices, wherein the monitoring devices comprise monitoring devices for electromagnetic flow measurement; and a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the control signal until a subsequent fluid flow estimate is to be obtained.
Claim 29
Independent Claim
108 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices, wherein the monitoring devices comprise monitoring devices for electromagnetic flow measurement; and a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the control signal until a subsequent fluid flow estimate is to be obtained.
Claim 30
Independent Claim
109 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices, wherein the monitoring devices comprise monitoring devices for thermal dilution flow measurement; and a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the control signal until a subsequent fluid flow estimate is to be obtained.
Claim 31
Independent Claim
109 words
An apparatus for repeatedly estimating fluid flow in a conduit, the apparatus comprising: one or more monitoring devices, wherein the monitoring devices comprise monitoring devices for thermal dilution flow measurement; and a source of electrical excitation signal that is applied to at least one of the one or more monitoring devices for at least a portion of an active period of a control signal sufficient to obtain a fluid flow estimate and is removed from the at least one of the one or more monitoring devices for at least a portion of an idle period of the control signal until a subsequent fluid flow estimate is to be obtained.
References Cited (Backward Citations)
US4198987A
Cited
US4227407A
Cited
US4622978A
Cited
SU1215659A1
Cited
US5313947A
Cited
US4787395A
Cited
US4819860A
Cited
US4809703A
Cited
US4866613A
Cited
US4905206A
Cited
US5046500A
Cited
US5083567A
Cited
US5156152A
Cited
SU1734697A1
Cited
US5111825A
Cited
US5107466A
Cited
US5113867A
Cited
US5316001A
Cited
US5103825A
Cited
EP0503839A2
Cited
US5174299A
Cited
US5291892A
Cited
US5373848A
Cited
US5383462A
Cited
US5535747A
Cited
US5476097A
Cited
US5544656A
Cited
US5640960A
Cited
US5865749A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-04-07 | 2006-10-07 | 2007-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-04-07 | 2010-10-07 | 2011-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-04-07 | 2014-10-07 | 2015-04-08 | $7700.00 | Window Closed / Lapsed |