Abstract: A high-intensity focused ultrasound (HIFU) therapeutic system includes a first ultrasonic transmitter and an ultrasonic imaging apparatus. The first ultrasonic transmitter transmits a HIFU therapeutic signal to a target. The ultrasonic imaging apparatus includes a second ultrasonic transmitter, an echo receiver, and a signal processor. The second ultrasonic transmitter alternately transmits a first imaging signal and a second imaging signal to the target, and the two form a complementary Golay code pair, where a bit period of a Golay code is determined by a transmission frequency of HIFU. The echo receiver receives a first echo signal, a second echo signal, and an interference signal. The signal processor performs a decoding operation on the first echo signal and the second echo signal and suppresses the interference signal to generate a high-quality ultrasonic image for monitoring a HIFU therapy.

Abstract: A method of ultrasound nonlinear imaging with high-bit Golay code excitation includes transmitting a first, a second, a third and a fourth Golay code signal wave which have more than four bits and are orthogonal pairs to each other; making the second and the forth Golay code signal wave be subtracted from the first and the third Golay code signal wave respectively to eliminate noise interference wave; performing compression filtering process to the above generated waves and taking a cross sum to generate two compressed code waves; taking the difference between the two compressed code waves to generate an image wave which includes at least two second-order harmonic waves; processing ultrasound nonlinear imaging by using the second-order harmonic waves and to generate an ultrasound image.

Abstract: An ultrasound Doppler detection method with Golay-encoded excitation is used to obtain the flow information of a moving object. A first Golay code is transmitted to the moving object for a reflection signal of the first Golay code and a second Golay code is transmitted to the moving object for a reflection signal of the second Golay code after waiting for a pulse repetition interval. The received reflection signals are match-filtered to generate a first and a second wave. The above steps are repeated several times. Then, a slow-time filter in the Doppler frequency domain whose low-pass cut-off frequency is a quarter of the pulse repetition frequency is used to filter out the first sidelobes of the first waves and the second sidelobes of the second waves. Finally, the ultrasound Doppler detection is formed according to the first mainlobes of the first waves and the second mainlobes of the second waves.

Abstract: An apparatus for ultrasound harmonic imaging and method therefor are provided. The apparatus includes a signal transmitting unit, a signal receiving unit and an image processing unit. The signal transmitting unit transmits a linearly or non-linearly frequency modulated up-sweep signal and a linearly or non-linearly frequency modulated down-sweep signal to a reflective body. The signal receiving unit receives an inter-modulation component generated through coupling between the up-sweep and the down-sweep signal and a second harmonic component of the up-sweep or the down-sweep signal reflected by the reflective body. The image processing unit is connected to the signal receiving unit, and performs ultrasound harmonic imaging to obtain an ultrasound harmonic image according to the inter-modulation component and the second harmonic component of the up-sweep or down-sweep signal, so as to improve image quality of harmonic imaging.

Abstract: A method of ultrasound nonlinear imaging with high-bit Golay code excitation includes transmitting a first, a second, a third and a fourth Golay code signal wave which have more than four bits and are orthogonal pairs to each other; making the second and the forth Golay code signal wave be subtracted from the first and the third Golay code signal wave respectively to eliminate noise interference wave; performing compression filtering process to the above generated waves and taking a cross sum to generate two compressed code waves; taking the difference between the two compressed code waves to generate an image wave which includes at least two second-order harmonic waves; processing ultrasound nonlinear imaging by using the second-order harmonic waves and to generate an ultrasound image.

Abstract: A method of ultrasound nonlinear imaging with Golay code excitation includes transmitting a first and a second Golay code signal wave which are orthogonal by each other; making the second Golay code signal wave be subtracted from the first Golay code signal wave to eliminate a first and a second noise interference wave to generate a third Golay code signal wave; using a first and a second compression filter to process the third Golay code signal wave to generate a first and a second compressed code signal wave; taking the difference between the first compressed code signal wave and the second compressed code signal wave to generate a third compressed code signal wave which includes at least two second-order harmonic waves; processing ultrasound nonlinear imaging by using the multi-frequency harmonic component waves to generate an ultrasound image.

Abstract: An ultrasound Doppler detection method with Golay-encoded excitation is used to obtain the flow information of a moving object. A first Golay code is transmitted to the moving object for a reflection signal of the first Golay code and a second Golay code is transmitted to the moving object for a reflection signal of the second Golay code after waiting for a pulse repetition interval. The received reflection signals are match-filtered to generate a first and a second wave. The above steps are repeated several times. Then, a slow-time filter in the Doppler frequency domain whose low-pass cut-off frequency is a quarter of the pulse repetition frequency is used to filter out the first sidelobes of the first waves and the second sidelobes of the second waves. Finally, the ultrasound Doppler detection is formed according to the first mainlobes of the first waves and the second mainlobes of the second waves.

Abstract: An apparatus for ultrasound harmonic imaging and method therefor are provided. The apparatus includes a signal transmitting unit, a signal receiving unit and an image processing unit. The signal transmitting unit transmits a linearly or non-linearly frequency modulated up-sweep signal and a linearly or non-linearly frequency modulated down-sweep signal to a reflective body. The signal receiving unit receives an inter-modulation component generated through coupling between the up-sweep and the down-sweep signal and a second harmonic component of the up-sweep or the down-sweep signal reflected by the reflective body. The image processing unit is connected to the signal receiving unit, and performs ultrasound harmonic imaging to obtain an ultrasound harmonic image according to the inter-modulation component and the second harmonic component of the up-sweep or down-sweep signal, so as to improve image quality of harmonic imaging.

Abstract: An ultrasonic diagnostic apparatus and imaging method for harmonic enhancement or suppression are disclosed. A fundamental transmit signal and a 3f0 transmit signal are combined to emit as an ultrasonic pulse signal. For harmonic enhancement, when the phase of 3f0 transmit signal is adjusted relative to that of the fundamental transmit signal, the harmonic signal is effectively enhanced due to the frequency-sum and frequency-difference components being in-phase for constructive combination. For harmonic suppression, the 3f0 phase can be further adjusted for about 180 degrees from that of maximal enhancement. The harmonic signal is effectively suppressed due to the two components being out-phase for destructive cancellation. With the apparatus, both harmonic enhancement and harmonic suppression can be achieved for better image quality in ultrasonic harmonic imaging.

Abstract: An acoustic method for measuring flow velocity of fluid is provided. First, a sound wave is emitted from a transduction surface of a transducer to a fluid. The transduction surface has at least two signal transduction sections. When the sound wave is scattered into a scattered signal by the fluid, the scattered signal is received by the transduction sections. According to the scattered signal, the maximum Doppler frequencies are calculated. Then, according to these maximum Doppler frequencies, the flow velocity of fluid is calculated.