Multi-Focus Acoustic Field Generation using Dammann Gratings for Phased Array Transducers

This repository contains the MATLAB scripts and resources used for the experiments and analysis presented in the paper:

Fushimi, Tatsuki, and Yusuke Koroyasu. "Multi-focus acoustic field generation using Dammann gratings for phased array transducers." Results in Physics (2024): 108040.

The study explores the generation of multi-focus acoustic fields using Dammann gratings applied to phased array transducers. It demonstrates the feasibility of controlled multi-focus field manipulation and validates the configurations with a conventional 16×16 transducer array.

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Repository Structure

├── codes/                   # Utility scripts and functions
├── visual_damman/           # Output data and visualizations for generated fields
├── selected_traps/          # Visualizations and data for selected configurations
├── transfer2pat.mat         # Data of selected configurations for further analysis
├── trans_x.csv              # Transducer x-coordinates
├── trans_y.csv              # Transducer y-coordinates
├── trans_z.csv              # Transducer z-coordinates
├── step_1_all_sweep_analyze_2d.m    # Step 1 script
├── step_2_analysis_sweep_2d.m       # Step 2 script
├── step_3_analysis_sweep_2d_pat.m   # Step 3 script (16x16 array validation)
├── step_4_translate_rotate.m        # Step 4 script
├── common_parameters.m      # Script for shared simulation parameters
└── README.md                # This file

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Usage Instructions

Prerequisites

• MATLAB installed with the necessary toolboxes:
  • Signal Processing Toolbox
  • Image Processing Toolbox
• Add the codes/ directory to your MATLAB path:

  addpath('codes/')

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Step-by-Step Workflow

Step 1: Sweep Analysis

File: step_1_all_sweep_analyze_2d.m

• Objective: Generate Dammann gratings for various configurations (x1, x2) and calculate the resulting acoustic pressure and phase fields.
• Key Outputs:
  • Pressure (abs(p1)) and phase (angle(p1)) visualizations saved in visual_damman/ as .png files.
  • Raw field data saved as .mat files for further analysis.
• How to Run:

  step_1_all_sweep_analyze_2d

Step 2: Sweep Data Analysis

File: step_2_analysis_sweep_2d.m

• Objective: Analyze the fields generated in Step 1, filter out invalid configurations, and identify promising setups based on:
  • Local pressure maxima.
  • -3dB ranges.
  • Threshold limits relative to pmax.
• Key Outputs:
  • Scatter plots for trap counts and peak intensities (fig_allsweep_trap_n.pdf, fig_allsweep_trap_p.pdf).
  • Invalid configurations stored in nan_coordinates.
• How to Run:

  step_2_analysis_sweep_2d

Step 3: Validate Selected Configurations with a Conventional 16×16 Array

File: step_3_analysis_sweep_2d_pat.m

• Objective: Validate the selected configurations (best_comb_trap) derived in Step 2 using a standard 16×16 transducer array.
• Key Outputs:
  • Pressure (hot colormap) and phase (jet colormap) visualizations saved in selected_traps/ as .png files.
  • Peak pressure data for each configuration saved in selected_trap_n_*.csv.
• How to Run:

  step_3_analysis_sweep_2d_pat

Step 4: Apply Spatial Transformations

File: step_4_translate_rotate.m

• Objective: Evaluate the robustness of selected configurations under spatial transformations (translation and rotation).
• Key Outputs:
  • Transformed pressure and phase field visualizations saved in selected_traps/ as .png files.
• How to Run:

  step_4_translate_rotate

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Key Functions and Utilities

• findpeaks2D.m: Identifies local maxima in 2D matrices.
• generate_damman.m: Generates Dammann gratings based on input parameters.
• pressure_calc_2d.m: Calculates the acoustic pressure field from the phase mask.
• pre_pressure_calc_2d_pat.m: Pre-computes parameters for efficient field simulations.

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Reproducibility

1. Generate the initial dataset:

   step_1_all_sweep_analyze_2d

2. Analyze and filter the results:

   step_2_analysis_sweep_2d

3. Validate with the 16×16 array:

   step_3_analysis_sweep_2d_pat

4. Apply spatial transformations:

   step_4_translate_rotate

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Citation

If you use this repository, please cite the original paper:

@article{fushimi2024multifocus,
  title={Multi-focus acoustic field generation using Dammann gratings for phased array transducers},
  author={Fushimi, Tatsuki and Koroyasu, Yusuke},
  journal={Results in Physics},
  year={2024},
  volume={26},
  pages={108040},
  doi={10.1016/j.rinp.2024.108040}
}

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Contact

For questions or feedback, please contact:
Dr. Tatsuki Fushimi
R&D Center for Digital Nature, University of Tsukuba
Email: [email protected]