Estimation of Flexible Ultrasound Array Shape Using Phase Coherence.

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Acoustic Engineering

Background:

• Flexible ultrasound array transducers offer advantages in medical imaging but their precise shape is difficult to determine.
• Accurate knowledge of transducer shape is critical for beamforming and image quality.

Purpose of the Study:

• To develop and validate an algorithm for estimating the shape of flexible ultrasound array transducers.
• To quantify the accuracy and computational efficiency of the proposed shape estimation method.

Main Methods:

• An algorithm exploiting phase variation across receive channels to compute an array shape focusing criterion.
• Implementation within a shape estimation workflow using simulated and experimental data from a 128-element, 2.5 MHz flexible array.
• Calibration of beam response against a known array shape for accurate estimation.

Main Results:

• The algorithm accurately predicts array shape with root mean square errors of 0.18 λ (simulated) and 0.4 λ (experimental).
• Shape estimation was achieved using data from a single transmit event.
• The calculation time for shape estimation was approximately 300 ms.

Conclusions:

• The developed algorithm provides a fast and accurate method for estimating flexible ultrasound array transducer shapes.
• This technique is essential for optimizing ultrasound imaging systems utilizing flexible arrays.
• The method demonstrates practical utility with both simulated and real-world experimental data.