Performance Study of a Torsional Wave Sensor and Cervical Tissue Characterization

Area of Science:

• Biomedical Engineering
• Materials Science
• Medical Imaging

Background:

• Elastography techniques map tissue stiffness using wave velocity.
• Quantitative elastography relies on shear wave velocity for shear stiffness.
• Current methods face limitations in separating wave types and managing applied pressure.

Purpose of the Study:

• Introduce a novel torsional wave sensor for soft tissue mechanical property characterization.
• Address limitations of existing elastography techniques, specifically wave separation and pressure sensitivity.
• Evaluate the robustness and applicability of the torsional wave elastography (TWE) technique.

Main Methods:

• Developed a torsional wave sensor with a rotational actuator disk and piezoceramic receiver.
• Transmitted and received shear waves through tissue-mimicking phantoms and cervical tissues.
• Conducted sensor sensitivity studies varying applied pressure and sensor-phantom incidence angle.
• Applied rheological models and static testing for cervical tissue characterization.

Main Results:

• The torsional wave sensor successfully isolates pure shear waves, mitigating interference.
• Sensor sensitivity studies demonstrated the technique's robustness under varying pressure and incidence angles.
• Characterization of cervical tissues was achieved by fitting experimental data to rheological models.
• Reconstruction of mechanical constants from propagated shear waves was demonstrated.

Conclusions:

• The novel torsional wave sensor provides a robust method for characterizing soft tissue mechanical properties.
• TWE overcomes key limitations of conventional elastography, offering improved accuracy.
• The methodology enables reconstruction of mechanical constants, validating the technique's potential for further research and clinical application.