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

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.

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.