Smoothed particle Galerkin modeling and experimental validation of pendulum-based scribing of porcine clots

Advancing cutting-based surgical technologies requires the knowledge of the interaction between tools and soft biomaterials which undergo large deformations before failure. The pendulum-based scribing is applied to deform the soft porcine clot and quantify its interaction with the tool. The pendulum apparatus has a 307 mm long swing arm with a 1 mm diameter blunt tip steel wire for scribing the porcine clot, which is cured by mixing the porcine whole blood and coagulant in a mold. After curing, the cover of the clot mold was removed to expose grooves of porcine clots in a fixture. Clot specimens were scribed at maximum speeds of 0.76 and 1.47 m/s. The cutting force was captured by a piezoelectric dynamometer beneath the clot fixture. High-speed video was recorded to observe the clot cutting and deformation during the scribing process. A smoothed particle Galerkin (SPG) model of the scribing process was developed to gain insights into the material deformation and to identify clot material properties for scribing by validating with experimentally measured scribing forces. The model exhibited concordance with experimental cutting force data, showing a deviation of 6.9 % at 0.76 m/s and 8.3 % at 1.47 m/s.