Fig. 3: A slipknot gauges mechanical transmission in surgical operations.
From: Slipknot-gauged mechanical transmission and robotic operation
a, A suture with a slipknot (red box) transmits a pre-encoded force to a surgical knot (blue box), termed a sliputure. b, The Fpeak emerges at slipknot opening to transmit mechanical information. c, The Fpeak is transmitted to the surgical knot during tying. A proper tying force within a feasible range produced a flat wound closure (middle image). Conversely, excessive force causes ischaemia (top image), whereas insufficient force leads to leakage (bottom image). d, The knot-tying force (mean ± s.d.; ribbons indicate the s.d.) of junior surgeons (n = 10; independent participants) and senior surgeons (n = 5; independent participants) (n = 10; independent experiments). With common sutures, junior surgeons showed lower force precision. Using sliputures without training significantly improved the precision of junior surgeons, even surpassing senior surgeons using common sutures. e, The probability density of the incision pressure is more compact with sliputures (n = 25; independent experiments). f, Feasible force range (n = 20; independent biological replicates) (blue) of ex vivo rat colonic injury repair was defined by Fmin (green, transition to no leakage) and Fmax (orange, transition to secondary leakage). g, Burst pressure (mean ± s.d.; ribbons indicate the s.d.) shows that sliputures produce initially lower pressures but plateau beyond controls after day 5, 2 days earlier (n = 3; independent biological replicates) than for common sutures. h,i, LSCI images of vessel visualization of rat colons after biopsy puncture and repair using sliputures (h) or common sutures (i). Dashed boxes mark punctured areas, which show that sliputures lead to improved blood supply. Colour bars represent relative perfusion units. j, Image of surgeons operating using the sliputure with laparoscopic instruments. k, The tying process with sliputures in laparoscopic repair of colonic injuries in live pigs. l, The repaired porcine colon regions by laparoscopic surgery appear flat when repaired using sliputures (left), whereas they appear bulging when repaired with common sutures (right). Scale bars, 1 mm (h) or 5 mm (k,l).
