A noninvasive surface wave technique for measuring finger's skin stiffness

Area of Science:

• Biomedical Engineering
• Rheumatology
• Medical Imaging

Background:

• Systemic sclerosis assessment, particularly limited cutaneous systemic sclerosis (lcSSc), relies on methods like the Modified Rodnan Skin Score (MRSS).
• MRSS presents challenges in accurately evaluating skin involvement in lcSSc patients.
• There is a need for noninvasive, objective techniques to quantify skin stiffness in lcSSc.

Purpose of the Study:

• To develop a compact surface wave elastography (CSWE) device for measuring finger skin stiffness.
• To establish a noninvasive method for assessing lcSSc, aligning with updated ACR/EULAR criteria.
• To evaluate the feasibility of CSWE for quantitative skin elasticity measurements.

Main Methods:

• A novel CSWE device was engineered to generate local harmonic vibrations on finger skin.
• Surface wave speed was measured non-contactly using a compact optical probe.
• Validation was performed against an ultrasound-based surface wave elastography (USWE) device using a phantom and a human volunteer.

Main Results:

• The CSWE device demonstrated successful noncontact measurement of surface wave speed on skin.
• Validation studies confirmed good agreement between CSWE and USWE measurements.
• The device was evaluated on four fingers of a volunteer, showing potential for multi-site assessment.

Conclusions:

• The developed CSWE device offers a promising noninvasive approach for measuring finger skin stiffness.
• CSWE may provide a valuable tool for objective assessment and monitoring of lcSSc.
• Further application of CSWE across various finger and hand areas could enhance lcSSc evaluation.