Patent ID: 9702969
Date: 2017-07-11
CPC Classifications: A61B,G01S

Claim:
1. An ultrasonic diagnostic imaging system which produces a Doppler audio signal of blood flow comprising: an ultrasound probe, operating at an ultrasonic Doppler transmit frequency f a Doppler demodulator, responsive to the Doppler ultrasound signals, which produces Doppler shift signals from the velocity of blood flow in an audio frequency band; a Doppler information display, responsive to Doppler shift signals, which displays blood flow velocity information based upon the Doppler shift; an audio Doppler system, responsive to the Doppler shift signals, which produces pitch-shifted audio Doppler without changing the displayed blood flow velocity, wherein the audio Doppler system is responsive to a user control to shift the pitch of the Doppler-shifted signals by a fractional or integer number of octaves by stretching the entire range of frequencies within the Doppler audio band and retaining harmonic relationships in the Doppler audio band so as to preserve the timbre of audio Doppler sounds, wherein the imaging system is operable with a selected one of a plurality of ultrasound probes, individually exhibiting a different nominal Doppler transmit frequency, and individually operable to acquire Doppler ultrasound signals from a location of blood flow; wherein the Doppler demodulator is further operable to detect Doppler shift signals in a frequency band which is a function of the nominal Doppler transmit frequency of a selected ultrasound probe; wherein the audio Doppler system is responsive to the detected Doppler shift signals to produce audio Doppler at a common nominal frequency irrespective of the nominal Doppler transmit frequency of the selected ultrasound probe; and wherein the audio Doppler system is responsive to the user control to produce audio Doppler sounds invariant to changes of a Doppler angle or based on an indication of a direction of blood flow adjusted by a user.