The study of quantitative friction-damage models at the interventional catheter-vascular tissues interface

Vascular interventional surgery is a minimally invasive treatment. It involves introducing catheters, guidewires, and other precision instruments into the human body to locally diagnose and treat internal diseases. However, mechanical contact, such as friction, compression, and collision, inevitably occurs during the intervention process. This can cause tissue damage. Currently, mechanical damage to vascular tissues is evaluated primarily in qualitative terms, which limits accurate reflection of both the extent of tissue damage and its influencing factors. This paper specifically researches friction injury between interventional catheters and vascular tissues. It develops the first quantification model of injury between catheters and blood vessels. Results showed that increases in normal force led to higher coefficients of friction (COF) and greater energy dissipation between the friction head and vascular tissue. In contrast, varying speeds produced a trend where COF and energy dissipation first increased, then decreased. A quantitative evaluation system for vascular tissue injury was established, based on indicators such as endothelial cells, glycoproteins, curled tissues, and intimal thickness on the vascular surface. Using this system, damage scores and damage grades were assigned to surface injuries in friction experiments. Pearson correlation analysis revealed a strong correlation between the COF and injury score. The link between normal load and sliding velocity was even higher than that between friction time and injury score. These experimental results lay the foundation for quantitative mechanical damage evaluation. They enable mapping of relations between mechanical factors and tissue damage.