BioSono provides a cyberspace (www.biosono.com) where researchers, engineers, and students can find useful reference and educational materials, conduct acoustic simulation, post questions on design and development, and get answers. The online KLM based transducer acoustic stack simulation, which is currently free, can help you choose piezoelectric, matching and backing material, and a tuning electrical network. The output from the model includes electrical transmit impedance, acoustic receive impedance, and the impulse or pulse-echo response. The ultrasound beam profile simulation provides the calculated transmitted ultrasound pressure field under certain excitation for a given transducer aperture in a number of different geometrical configurations, including circular elements (flat and concave piston), rectangular elements, linear arrays, convex arrays, and 2D arrays. The simulation is based on Field II, which is a free program that utilizes the spatial impulse response method, and has been validated by many researchers for accuracy. In addition to the web based acoustic simulation, we also provide pulse-echo system, transducers, and customized design and develop services.
Transducer KLM Model Simulation
Beam Profile Simulation
SonoLab Echo I
Time Gain Control
High Intensity Focus Ultrasound,HFU, multi-channel transmitter, freqeuncy tracking
Pulse width modulated (PWM) wave is commonly used to drive HIFU transducer element through a class-E amplifier. For a fixed transmit voltage, the power applied on the transducer element is controlled by the duty factor of the PWM. When duty factor is 100 percent, the element gets its maximal power, which is inverse proportional to its absolute impedance value.
Voltage and current of the channel need to be monitored in case of a short in the load and also for the frequency tracking purpose. The center frequency of the piezoelectric element may drift when temperature is increased.
The following is a description of a typical multi-channel HIFU system. It consists of a control unit and several RF modules.
As shown in the above figure, the control unit includes user interface and control logic. The user interface takes parameter inputs such as transmit voltage, center frequency, duty factor, delays for each element. It passes the parameters to RF modules via RS-232 ports. It also sends out a master synchronization clock and a master trigger to each RF module using a digital edge signal.
A RF module includes several channels upon user needs, normally up to 8. A channel will be shut down automatically by hardware if the output current exceeds the limit. An A/D is included to digitize the sensed voltage and current of the selected channel via a multiplexer.
Rs-232 port will talks to a control unit or a PC to receive transmit voltage, center frequency, and delay profile. All the channels share the same one HV source within one RF module and it is programmable through D/A control. Different RF modules will be synchronized by trigger and master clock signals.
Email email@example.com for a quote.
© 2007-2017 BioSono Inc. All Rights Reserved.
45401 Research Ave. Suite 229, Fremont, CA. Tel:510.378.1672. Fax: 510-338-9217. Email:firstname.lastname@example.org