Optimized deployment of heat-activated surgical staples using thermography

Abstract

We have developed a suture analogue, suitable for use in laparoscopic surgery, in the form of a staple constructed from NiTi shape memory alloy (SMA). Closure of the staple is effected by resistive heating via a (50–100 ms) pulse of electrical current (≈5 A). In order to optimize deployment protocols and minimize thermal collateral damage to tissue, the heat sink effect of the electrical contact rails, as well as the presence of contact hotspots must be considered. Here, we have employed high-resolution thermal imaging to observe the dynamic temperature distributions in SMA staples as a function of the pulse parameters. This has facilitated process optimization and also provided data from which to validate computational finite-element models of the heat transport phenomena.