A Simple Technique for Visualizing Ultrasound Fields Without Schlieren Optics

Area of Science:

• Acoustics and Optics
• Medical Imaging Technology

Background:

• Schlieren optics are commonly used for ultrasound field visualization.
• Existing methods can be complex or lack sensitivity for certain applications.

Purpose of the Study:

• To introduce a simplified, sensitive technique for visualizing ultrasound fields.
• To demonstrate the technique's applicability to medical ultrasound transducers.

Main Methods:

• Utilized direct shadowgraphy with focusing optics (a camera) instead of a physical screen.
• Employed image subtraction to eliminate non-deflecting light and enhance sensitivity.
• Experimented with 1-MHz focused and 20-MHz miniature ultrasound transducers.

Main Results:

• Successfully visualized alternate pressure changes in short-pulsed ultrasound fields.
• Demonstrated flexible control over virtual screen position and optical magnification.
• Achieved enhanced sensitivity through image subtraction, overcoming limitations of standard shadowgraphy.

Conclusions:

• The proposed direct shadowgraphy technique offers a simple and effective method for ultrasound field visualization.
• This technique is valuable for evaluating medical ultrasound fields, including therapy and intravascular imaging transducers.