Two dimension and three dimension imaging with coded pulses based on speed changes of sound/ultrasound

A method of using time of flight (TOF) shift of the sound pulses to calculate a velocity of moving objects in a continuous, a pulsed and a color ultrasound, the method comprising:

• setting a baseline wherein the baseline in the pulsed ultrasound is calculated TOF between a transducer and a gate and in the continuous ultrasound is a time of an emitted period, and a TOF shift equals to zero at the baseline;
• for pulsed ultrasound, detecting TOF is a time from sending ultrasound pulses to receiving the reflected ultrasound pulses, and for continuous ultrasound, a reflected period is a time between two consecutive reflected sound pulses from a sampling point;
• calculating the TOF shift wherein the TOF shift for the pulsed ultrasound is a time difference between the calculated TOF and the detected TOF, and TOF shift for the continuous ultrasound is a time difference between is the emitted period and the reflected period;
• and
• calculating the velocity of the moving objects (Vobjects) based on an equation of TOF shift including an angle θ of the sound beam made with the moving objects, an average speed (Vavg) of the sound pulses in the transmitting medium, the transducer frequency (f), wherein the TOF shift is the TOF shift for the continuous, the pulsed and the color ultrasound, the equation of the TOF shift is:
• TOF
• 
• 
• shift
• =
• 2
• ×
• V
• objects
• ×
• f
• ×
• cos
• 
• (
• θ
• )
• V
• avg

A method of calculation of the detecting depth and the moving velocity of sampling points with coded sound pulses comprising:

• a transducer contains one pair or more of emitting PZT elements and receiving PZT elements, assigning different numbers of the sound pulses within each pulse duration to form different pulse characters, a resting period is a time between each adjacent pulse duration;
• the emitting PZT elements emit specifically coded pulse characters, which endow information of an emitting time for each pulse character, and the resting period for the emitted sound pulses keeps identical;
• the receiving PZT elements receive reflected sound pulses, and decode received pulse characters to compare with the emitted codes of the pulse characters, TOF is obtained from a time between the emitted pulse character and the same reflected pulse character, and TOF shift is obtained from a time difference between the emitted resting period and the correspondingly received resting period;
• identifying motionless sampling points from the reflected sound pulses with identical value of the TOF and zero value of the TOF shift, therein the depth of the motionless sampling points is calculated from the TOF;
• and
• identifying moving sampling points from the reflected sound pulses with variable values of the TOF and the TOF shift, therein the velocity of the moving sampling points is calculated with the equation of the TOF shift, the depth of the moving sampling points is a half multiplication value of the sum of the TOF and the TOF shift with the average velocity of sound in the transmitting medium, for forward moving sampling points, the TOF shift is positive value, and for reversely moving sampling points, the TOF shift is negative value, the equation of calculating the depth of the moving sampling points comprising:
• depth of moving sampling points=Vavg×(TOF+TOF shift)/2