Ultrasound Beam Profile or Aperture Radiation Pattern Simulation

BioSono Inc. was founded in the summer of 2007 in Silicon Valley, California. 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 both the impulse and pulse-echo response. The ultrasound beam profile simulation is a free web/email based service. This simulation can provide 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. The calculation is too time-consuming, and it may take up to one day for the server to send the user results by email. The ultrasound wave propagation simulation is also a free web/email based service. For a given 2D space, and a given target (round or square), an .avi or .gif movie file will be generated with an either a spherical, or plane incident wave passing through it. It may take up to one day for the server to send user results by email. In addition to the web based acoustic simulation, we also provide customized, more complicated simulations, transducer, and electrical designs.

The ultrasound beam profile simulation service is free to all users. Select an aperture, input your desired parameters, choose an electrical excitation, set the range parameters for the view, and click the "Submit" button, the simulation will be triggered automatically. It is time consuming, and depends on how many tasks in front of you. The results will be sent to you through email automatically by server.
Currently, the services include flat piston, concave piston, linear array, phase array, convex linear array, and 2D array aperture. The results is 2D acoustic intensity distribution in bitmap file format. For more apertures or more results formats, you may submit a customized simulation. The view is the area in front of the aperture of the ultrasound transducer in the ultrasound beam simulation. The program will calculate point by point of acoustic pressure in the view field to cover your interested area. So it is important for your to specify where to start, stop and by what step. As shown in the view picture, the Axial direction is perpendicular to the transducer. The Lateral direction is the array direction, and the elevation direction is perpendicular to the Axial-Lateral plane. The origin of the coordinates (0,0,0) is the ultrasound transducer surface center.

Ultrasound beam profile simulation is also called ultrasound aperture radiation pattern. It is an important step in ultrasound simulation or modeling. From KLM model simulation, the acoustic output of the ultrasound transducer can be obtained under any given electrical excitation. The acoustic pressure, or particle movement on surface of the ultrasound transducer, will propagates into free space, and form a intensity field in front of it. In most cased, the transducer aperture is far bigger than the ultrasound wavelength and the intensity field has a shape similar to flashlight beam, so is called ultrasound beam. For imaging or HIFU application, a confined energy field or a narrow beam is desired which leads to a good ultrasound image resolution or beam focus. In some special cased a more uniformed beam is required. In general, a large aperture is required to achieve strong focus, and thus better resolution. A very small aperture compared to ultrasound wavelength generates a spherical like wave. The beam profile can be quantitatively studied by 1D beam intensity profile, 2D beam intensity, 2D acoustic pulse instant spatial distribution, animation of acoustic pulse propagation.