Doppler ultrasound method and apparatus for monitoring blood flow and detecting emboli
First Claim
1. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the method comprising:
- compiling movement information for a plurality of locations along the ultrasound beam, the movement information including detected Doppler shift signal power and associated velocity for a length of time having a plurality of time periods; and
determining the occurrence of an embolic event from the compiled movement information for each of the time periods.
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Accused Products
Abstract
A pulse Doppler ultrasound system and associated methods are described for monitoring blood flow and detecting emboli. A graphical information display includes simultaneously displayed depth-mode and spectrogram displays. The depth-mode display indicates the various positions along the ultrasound beam axis at which blood flow is detected. These positions are indicated as one or more colored regions, with the color indicating direction of blood flow and varying in intensity as a function of detected Doppler ultrasound signal amplitude or detected blood flow velocity. The depth-mode display also includes a pointer whose position may be selected by a user. The spectrogram displayed corresponds to the location identified by the pointer. Embolus detection is also provided.
99 Citations
97 Claims
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1. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the method comprising:
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compiling movement information for a plurality of locations along the ultrasound beam, the movement information including detected Doppler shift signal power and associated velocity for a length of time having a plurality of time periods; and
determining the occurrence of an embolic event from the compiled movement information for each of the time periods. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
subtracting a respective background power level from the compiled movement information for each of the plurality of locations; and
performing a plurality of binary characterization tests to determine whether the resultant compiled movement information is indicative of an embolic event.
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3. The method of claim 2 wherein the plurality of binary characterization tests comprises identifying from the resultant compiled movement information the position of the embolic event.
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4. The method of claim 3, further comprising determining whether the position of the embolic event occurs between a first depth and a second depth.
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5. The method of claim 3 wherein identifying the position of the embolic event comprises locating the depth of maximum detected power along the ultrasound beam.
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6. The method of claim 2 wherein the plurality of binary characterization tests includes determining whether the resultant compiled movement information is indicative of an embolic event having a velocity not exceeding a high-end blood flow velocity.
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7. The method of claim 6 wherein the high-end blood flow velocity is approximately 2 meters per second.
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8. The method of claim 2 wherein the plurality of binary characterization tests includes determining whether the resultant compiled movement information is indicative of an embolic event having uniform motion away from or towards the source of the ultrasound beam for a minimum number of time intervals.
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9. The method of claim 2 wherein the plurality of binary characterization tests includes determining whether the resultant compiled movement information of a potential embolic event has sufficient power fluctuation from the background power level.
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10. The method of claim 1, further comprising displaying the compiled movement information for observation by a user.
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11. The method of claim 10 wherein determining the occurrence of an embolic event is made visually by the user.
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12. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the method comprising:
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compiling for a plurality of time periods movement information for a plurality of locations along the ultrasound beam, the movement information including detected Doppler shift signal power and associated velocity;
subtracting a respective background power level from the compiled movement information for each time period and each of the plurality of locations;
displaying the resultant compiled movement information on a display device; and
visually determining from the displayed complied movement information the occurrence of an embolic event. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the method comprising:
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compiling for a plurality of time periods movement information for a plurality of locations along the ultrasound beam, the movement information including detected Doppler shift signal power and associated velocity;
for each time period, removing movement information having a detected velocity less than a velocity threshold from the compiled movement information; and
displaying on a display device the resultant compiled movement information along time and position axes; and
visually determining from the displayed resultant complied movement information the occurrence of an embolic event. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the Doppler ultrasound system compiling for a plurality of time periods movement information including detected Doppler shift signal power and associated velocity for a plurality of locations along the ultrasound beam, the method comprising:
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removing from the compiled movement information for each time period movement information having a detected velocity less than a velocity threshold; and
performing for each time period a plurality of binary characterization tests to determine whether the resultant compiled movement information is indicative of an embolic event. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the Doppler ultrasound system compiling for a plurality of time periods movement information including detected Doppler shift signal power and associated velocity for a plurality of locations along the ultrasound beam, the method comprising:
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subtracting a respective background power level from the compiled movement information for each time period and each of the plurality of locations;
for each time period, removing movement information having a detected velocity less than a velocity threshold from the subtracted compiled movement information; and
performing a plurality of binary characterization tests for each time period to determine whether the resultant compiled movement information is consistent with the occurrence of an embolic event. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50)
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51. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the Doppler ultrasound system compiling for a plurality of time periods movement information including detected Doppler shift signal power and associated velocity for a plurality of locations along the ultrasound beam, the method comprising:
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performing for each time period a plurality of binary characterization tests indicative of embolic events on the compiled movement information to identify the occurrence of an embolic event; and
rejecting false positive embolic events. - View Dependent Claims (52, 53, 54, 55, 56, 57, 58, 59, 60)
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61. A method for detecting embolic events in a Doppler ultrasound system sensing motion along an ultrasound beam, the Doppler ultrasound system compiling for a plurality of time periods movement information including detected Doppler shift signal power and associated velocity for a plurality of locations along the ultrasound beam, the method comprising:
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subtracting a respective background power level from the compiled movement information for each time period and each of the plurality of locations;
performing for each time period a plurality of binary characterization tests indicative of embolic events on the resultant compiled movement information to identify the occurrence of an embolic event; and
rejecting false positive embolic events. - View Dependent Claims (62, 63, 64, 65, 66, 67, 68, 69, 70)
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71. A Doppler ultrasound system for sensing motion along an ultrasound beam and detecting embolic events, the system comprising:
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an ultrasound transducer operable to detect ultrasound signals and responsively produce corresponding electrical signals;
signal processing circuitry coupled with the transducer to receive the electrical signals and compile for a plurality of time periods movement information including detected Doppler shift signal power and associated velocity for a plurality of locations along the ultrasound beam; and
detection circuitry coupled to receive the compiled movement information from the signal processing circuitry and operable to perform a plurality of binary characterization tests for each time period to determine whether the compiled movement information is consistent with the occurrence of an embolic event. - View Dependent Claims (72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83)
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84. A computer-readable medium having a computer executable program for detecting embolic events, the computer program comprising instructions, which when executed by a Doppler ultrasound system sensing motion along an ultrasound beam perform the steps of:
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compiling for a plurality of time periods movement information for a plurality of locations along the ultrasound beam, the movement information including detected Doppler shift signal power and associated velocity; and
performing a plurality of binary characterization tests for each time period to determine whether the compiled movement information is indicative of the occurrence of an embolic event. - View Dependent Claims (85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97)
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Specification