Gelatine-alginate complex gel: a new acoustically tissue-equivalent material

Area of Science:

• Biomaterials Science
• Acoustics
• Medical Physics

Background:

• Medical ultrasonics requires reliable tissue-equivalent phantoms for accurate imaging and device testing.
• Existing phantom materials often lack long-term stability or tunable acoustic properties.

Purpose of the Study:

• To develop and characterize novel gelatine-alginate complex gels for use as tissue-equivalent phantoms in medical ultrasonics.
• To evaluate the acoustic and physical properties of these gels, focusing on speed of sound, attenuation, and volume stability.

Main Methods:

• Preparation of gelatine-alginate complex gels.
• Measurement of acoustic properties (speed of sound, attenuation) at 20°C.
• Assessment of volume stability under water immersion over 300 days.
• Evaluation of chemical and bacterial degradation resistance.

Main Results:

• Speed of sound measured at 1520 ms⁻¹ with a thermal coefficient of +2.6 ms⁻¹/°C.
• Unloaded gel attenuation is 0.12 dB cm⁻¹ MHz⁻¹, tunable up to 0.5 dB cm⁻¹ MHz⁻¹ by loading with microspheres.
• Volume stability within ±2% over 300 days, a significant improvement over simple and cross-linked gelatin gels.

Conclusions:

• Gelatine-alginate complex gels demonstrate promising acoustic and physical properties for medical ultrasound phantom applications.
• The enhanced volume and degradation stability make these gels superior to conventional gelatin-based phantoms.
• Tunable acoustic attenuation allows for versatile phantom design for various ultrasonic imaging scenarios.