Doppler ultrasound method and apparatus for monitoring blood flow and detecting emboli

Claim 3

The method of claim 1 wherein the velocity threshold is approximately equal to 7 cm/s.

Claim 4

The method of claim 1 wherein the plurality of binary characterization tests comprises identifying from the resultant compiled movement information the position of the embolic event.

Claim 5

The method of claim 3 , further comprising determining whether the position of the embolic event occurs between a first depth and a second depth.

Claim 6

The method of claim 3 wherein identifying the position of the embolic event comprises locating the maximum power for each of the plurality of locations along the ultrasound beam.

Claim 7

The method of claim 1 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.

Claim 8

The method of claim 6 wherein the high-end blood flow velocity comprises approximately 2 meters per second.

Claim 9

The method of claim 1 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.

Claim 10

The method of claim 1 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.

Claim 11

The method of claim 1 , further comprising displaying the resultant compiled movement information for observation by a user.

Claim 12

The method of claim 1 , further comprising automatically incrementing a counter when it is determined that the resultant compiled movement information is indicative of an embolic event.

Claim 13

A Doppler ultrasound system for sensing motion along an ultrasound beam and detecting embolic events, the system comprising: 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 for a plurality of time periods compile 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 subtract a respective background power level from the compiled detected Doppler ultrasound power for each of the plurality of locations and time periods, remove movement information having a detected velocity less than a velocity threshold from the subtracted compiled movement information for each time period, perform for each time period a plurality of binary embolus characterization tests on the resultant compiled movement information, review the results therefrom, and reject any false positive identifications of an embolic event.

Claim 14

A Doppler ultrasound system for sensing motion along an ultrasound beam and detecting embolic events, the system comprising: 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 for a plurality of time periods compile 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 subtract a respective background power level from the compiled detected Doppler ultrasound power for each of the plurality of locations and time periods, remove movement information having a detected velocity less than a velocity threshold from the subtracted compiled movement information for each time period, perform for each time period a plurality of binary embolus characterization tests on the resultant compiled movement information, review the results therefrom, and reject any false positive identifications of an embolic event.

Claim 15

The Doppler ultrasound system of claim 12 , further comprising a display device coupled to the signal processing circuitry and the detection circuitry to display the resultant compiled movement information for a user.

Claim 16

The Doppler ultrasound system of claim 12 wherein the detection circuitry is further operable to count the number of events determined to be embolic.

Claim 17

The Doppler ultrasound system of claim 12 wherein the velocity threshold approximately equal to 7 cm/s.

Claim 18

The Doppler ultrasound system of claim 12 wherein the plurality of binary characterization tests comprises identifying the position of the embolic event by locating the maximum power for each of the plurality of locations along the ultrasound beam and time periods.

Claim 19

The Doppler ultrasound system of claim 16 , further comprising determining whether the position of the embolic event occurs between a first depth and a second depth.

Claim 20

The Doppler ultrasound system of claim 12 wherein the plurality of binary characterization tests comprises determining whether the resultant compiled movement information is consistent with an embolic event having a velocity not exceeding a high-end blood flow velocity.

Claim 21

The Doppler ultrasound system of claim 18 wherein the high-end blood flow velocity is approximately 2 meters per second.

Claim 22

The Doppler ultrasound system of claim 12 wherein the plurality of binary characterization tests comprises determining whether the resultant compiled movement information is indicative of an embolic event having uniform motion away from or towards the ultrasound transducer for minimum time intervals.

Claim 23

The Doppler ultrasound system of claim 12 wherein the plurality of binary characterization tests comprises determining whether the resultant compiled movement information of a potential embolic event has sufficient power fluctuation from the background power level.

Claim 24

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 and 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, perform the steps of: subtracting a respective background power level from the compiled movement information for each of the plurality of locations and time periods; for each time period, removing from the subtracted compiled movement information movement information having a detected velocity less than a velocity threshold; performing for each time period a plurality of embolus binary characterization tests to determine whether the resultant compiled movement information is indicative of an embolic event; and reviewing the results of the binary characterization tests to reject any false positive identifications of an embolic event.

Claim 25

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 and 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, perform the steps of: subtracting a respective background power level from the compiled movement information for each of the plurality of locations and time periods; for each time period, removing from the subtracted compiled movement information movement information having a detected velocity less than a velocity threshold; performing for each time period a plurality of embolus binary characterization tests to determine whether the resultant compiled movement information is indicative of an embolic event; and reviewing the results of the binary characterization tests to reject any false positive identifications of an embolic event.

Claim 26

The computer readable medium of claim 22 wherein the velocity threshold approximately equal to 7 cm/s.

Claim 27

The computer readable medium of claim 22 wherein the plurality of binary characterization tests comprises identifying from the resultant compiled movement information the position of the embolic event.

Claim 28

The computer readable medium of claim 24 , further comprising determining whether the position of the embolic event occurs between a first depth and a second depth.

Claim 29

The computer readable medium of claim 24 wherein identifying the position of the embolic event comprises locating the maximum power for each of the plurality of locations along the ultrasound beam.

Claim 30

The computer readable medium of claim 24 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.

Claim 31

The computer readable medium of claim 24 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.

Claim 32

The computer readable medium of claim 22 wherein the plurality of binary characterization tests includes determining whether the resultant compiled movement information is consistent with an embolic event having a velocity not exceeding a high-end blood flow velocity.

Claim 33

The computer readable medium of claim 29 wherein the high-end blood flow velocity comprises approximately 2 meters per second.

Claim 34

The computer readable medium of claim 22 , further comprising displaying the resultant compiled movement information for observation by a user.

Claim 35

The computer readable medium of claim 31 wherein determining whether the resultant compiled movement information is consistent with characteristics of an embolic event is made visually by the user.

Claim 36

The computer readable medium of claim 22 , further comprising automatically incrementing a counter when it is determined that the resultant compiled movement information is consistent with the characteristics of an embolic event.