Instant variable stiffness in cardiovascular catheters based on fiber jamming

Area of Science:

• Biomedical Engineering
• Medical Devices
• Minimally Invasive Surgery

Background:

• Variable stiffness (VS) catheters enhance miniature surgical instruments for minimally invasive surgeries (MISs).
• Existing VS catheters using phase-changing materials have slow stiffness modulation rates (≈90 s), increasing surgery duration.
• There is a need for VS catheters with rapid stiffness changes to improve surgical efficiency and safety.

Purpose of the Study:

• To develop and evaluate a novel VS catheter based on fiber jamming (FJ) technology.
• To achieve instantaneous stiffness changes for seamless catheter operation in MISs.
• To enhance the safety and effectiveness of cardiovascular catheters.

Main Methods:

• A novel VS catheter design utilizing fiber jamming (FJ) was developed.
• The catheter incorporates hundreds of ultrathin fibers within a 2.3-mm slender body.
• Stiffness modulation and bending capabilities were tested, focusing on response times and degree of change.

Main Results:

• The FJ-based VS catheter demonstrated instant stiffness changes (≤300 ms), significantly faster than existing technologies.
• Achieved up to a 6.5-fold increase in stiffness.
• Enabled complex bending profiles within seconds using a two-segment design.
• The FJ design eliminates the need for internal electric currents or heating, enhancing patient safety.

Conclusions:

• The proposed FJ-based VS catheter offers instantaneous stiffness modulation, substantial stiffness change, and enhanced safety for MIS applications.
• This technology has the potential to set new benchmarks in MIS, improving treatment for complex diseases.
• The rapid response and safety features make it a promising advancement for cardiovascular interventions.