Abstract:
본 발명은 임피던스 매칭 장치로, 시스템으로부터 출력된 전송 펄스 및 상기 전송 펄스의 반사 수신 펄스가 통과하는 매칭 소자 어레이부와, 상기 펄스들로부터 펄스 정보를 추출하고, 상기 펄스 정보에 상응하는 임피던스값을 산출하고, 수신 펄스의 응답 특성이 가장 좋은 매칭 임피던스값으로 산출하는 추출/산출부; 상기 매칭 임피던스값에 따라 상기 매칭소자 어레이부를 라우팅하는 어레이 제어부; 상기 전송 펄스의 주파수를 캐리어 주파수로 변환하여 상기 매칭 소자 어레이부에 출력하는 제 1 변환부와; 상기 매칭 소자 어레이부에서 출력되는 캐리어 주파수를 저주파수로 변환하는 제 2 변환부; 및 상기 제 1 변환부 및 제 2 변환부의 주파수 변환을 제어하는 신호를 출력하는 변환 제어부를 포함한다.
Abstract:
In one embodiment, a method for determining the voltage current phase relationship of a piezoelectric phacoemulsification handpiece generally includes the steps of obtaining an analog AC voltage signal corresponding to the operating AC voltage of a piezoelectric handpiece along with an analog AC current signal corresponding to the operating AC current of the piezoelectric handpiece. Using reference detection circuits, a digital voltage signal and a digital current signal is produced. A synchronous sample clock is taken that has a frequency that is 2N times faster than the frequency of the operating ultrasonic handpiece (i.e., driving frequency), where N is the number of digital bits allocated to the sample clock.. This clock measures the time between onsets of a voltage and current cycle. This time value equates to the phase time delta between the two signals. Dividing the synchronous sample clock to obtain the driving frequency ensures the signals are synchronous. Further dividing the end count value into 360° results in the phase shift between the two signals in degrees that is independent of the operating frequency.
Abstract:
A transducer is optimally driven at or near its resonant frequency by a driver system that adapts to variations and/or changes to the resonant frequency of the transducer due to variations in piezo materials, manufacturing, assembly, component tolerances, and/or operational conditions. The system may include an output controller, a phase track controller, a frequency generator, a drive, circuitry to determine a phase angle between the transducer voltage and transducer current, and circuitry to obtain transducer admittance from the transducer voltage and transducer current.
Abstract:
Device, system and method of determining an acoustic contact between an ultrasonic transducer and a body subject to ultrasonic energy generated by the transducer. For example, a method of determining an acoustic contact between an ultrasonic transducer and a body subject to ultrasonic energy generated by the transducer may include determining an acoustic contact level between the transducer and the body based on at least one value of at least one parameter related to an electrical impedance at the transducer. Other embodiments are described and claimed.
Abstract:
An ultrasonic imaging system (100) having an ultrasonic probe (110) which improves poor harmonic performance of existing transmit circuits through the use of a linear high-voltage transmit amplifier (129) on each sub-channel to amplify low-voltage arbitrary shape transmit waveforms generated by the ultrasonic system (100) is presented. The linear high-voltage amplifier (129) of the ultrasonic probe (110) amplifies low-voltage arbitrary shape transmit waveforms beam-formed by a micro-beam-former (119) of the ultrasonic system (100).
Abstract:
A method and apparatus for delivering energy during a surgical procedure such as phacoemulsification is provided. The method and apparatus include applying energy during at least one pulsed energy on period, typically sufficient or intended to rapidly induce and beneficially employ transient cavitation. Applying energy during the pulsed energy on period comprises applying energy during a first high energy period, and applying energy during a second nonzero lower energy period.
Abstract:
Phacoemulsification apparatus includes a phacoemulsification handpiece having a needle and an electrical system for ultrasonically vibrating said needle along with a power source for providing pulsed electrical power source for providing pulsed electrical power to the handpiece electrical system. Irrigation fluid is provided to the handpiece needle and aspirating fluid is removed from the handpiece needle and aspirating fluid is removed from the handpiece needle. A determination of a voltage current phase relationship of the provided electrical power is made and in response thereto a control system varies a power level duty cycle provided to the handpiece electrical system from the power source and/or modify the aspiration flow rate. In addition, a separate input enables manual control of pulse amplitude and the control system in response to a selected amplitude determines a duty cycle of the provided pulsed electrical power.
Abstract:
The present invention provides a microfabricated acoustic transducer with suppressed substrate modes. The modes are suppressed by either thinning te substrate such that a longitudinal ringing mode occurs outside of the frequency band of interest or by applying a judiciously designed damping material on the backside of the transducer substrate.