Schematic of a series of slipknots on a string that transmit force signal spectra to gauge robotic arm operations. b, The process of mechanical information writing and reading in a slipknot. Mechanical information is written into a slipknot by tying it with a specific force input. The mechanical model processes this force input, incorporating features such as physical factors and topology. The mechanical information is then output as the peak force, Fpeak, during the knot-releasing process of pulling the slipknot. c–e, The slipknot-gauged mechanical transmission strategy was validated in scenarios including micro-operations (c), collaborative manipulation (d) and heavy-load rescue missions (e). Scale bars, 1 mm (c), 2 cm (d) or 10 cm (e). (Jam Press/Zhejiang University)
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Boffins have unveiled a breakthrough that could see robots carrying out ultra-delicate surgery better than humans.
Scientists have cooked up a crafty new way for both rookie medics and machines to “feel” what they’re doing, giving them the magic touch normally only found in top surgeons.
The team’s secret weapon is a clever pressure-adjusting slipknot that lets doctors – and now robots – deliver the kind of precise, feather-light force usually expected from seasoned pros, as reported by Need To Know.
“When applied to surgical repair, this mechanism helped inexperienced surgeons to improve their knotting-force precision by 121%, enabling them to perform surgical knots as good as those of experienced surgeons,” researchers said.
And the perks don’t stop there.
The so-called slipknot can boost blood supply and speed up tissue healing after operations, meaning patients could be back on their feet faster than ever.
But this isn’t just a flashy party trick.
Boffins say the slipknot could be rolled out across a whole range of medical devices, opening the door to a new era where machines and medics work closer than ever.
Robotic surgery has long struggled with suturing because human surgeons can sense tiny changes in tension – something robots simply couldn’t match.
Snapshots of an opening slipknot by high-speed photography (a), micro-CT scanning (b) and finite element result (c). Scale bars, 1?mm. The slipknot transitions slowly from the initial state (first column) to the snap-out state (fourth column) when the first Reidemeister move, R1, occurs and then rapidly opens (last column). d, Experimental and modelled (both theoretical and numerical) forcedisplacement curves of a slipknot. The theoretical model involves two stages: before (stage?1) and after (stage?2) the R1 move. e, Fpeak values of 500 slipknots on a fluorocarbon filament string tied with Ftying?=?7.500?N. The values are located within 2.945?±?0.135?N (mean?±?s.d., n?=?500 independent samples), showing a consistency of 95.4%. f, Mechanical model of the two stages before and after the R1 move. Black and grey lines denote the rod part, and orange tubes indicate the constraint. Inset, the R1 move in a simulation. g, Experimentally tested Fpeak values (mean?±?s.d.) in different configurations of single-knot, double-knot and triple-knot loops (n?=?5 independent samples). h,i, Fpeak changes over time (h) (mean?±?s.d., n?=?5 independent samples) and testing speed (i) (mean?±?s.d., n?=?5 independent samples) validate the stability of the slipknots in long-term and dynamic tests. Points in the figures denote experimental data, lines indicate mean values and shading reflects the uncertainty. Grey areas in these figures represent the unstable regions. (Jam Press/Zhejiang University)
Until now.
The Zhejiang University team’s simple but genius fix means that when the knot begins to slip, it sends a signal to the robot telling it to stop automatically – almost like giving the machine a built-in sixth sense.
They’ve even given their creation a name: the “sliputure” – a suture with a gradually loosening slipknot that doubles as a basic sensor.
With this deceptively simple trick, the gap between man and machine is shrinking fast, paving the way for robots capable of performing unbelievably intricate procedures – and saving countless lives in the future.
Imagine a robot that could lace your shoes perfectly or stitch up an abdomen with flawless finesse – all without fancy electronics.
That’s exactly what this slipknot breakthrough makes possible, according to the research, which was published in the Nature journal on 27 November.
Zhejiang University, based in eastern China, may just have given the world its first real taste of robot surgeons that can outperform humans.
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). (Jam Press/Zhejiang University)The mechanical transmission route of applying sliputures in robotic surgery. Real-time imaging provides visual cues to humans and robots to enable intelligent operation to gauge the surgical knot-tying force. b,c, Repaired tissue regions of the colon in live pigs by robotic surgery show a flat appearance with sliputures (b) but tissue extrusion and bulging with common sutures (c). Scale bar, 5?mm. d, A closed-loop robotic system that uses sliputures for active arm-movement control was validated through a vision-based automatic-braking experiment in an in vivo porcine model. Real-time image processing for slipknot detection. After the slipknot opens, a stop command was activated to terminate movement of the robotic arm. Scale bar, 5?mm. e, The slipknot was detected from the RGB images and converted into real-time greyscale images. Slipknot opening was detected by matching the images to the opened slipknot configuration. f, Protocol and methods of slipknot-gauged mechanical transmission. g,h, Slipknot-enhanced safer humanrobot interactions. Scale bar, 5?cm. g, The proposed slipknot-integrated tendon-driven robotic arm demonstrates free motion capability at the elbow and wrist joint with the slipknot maintained. h, During humanrobot interactions, the slipknot is opened and releases the tension when the robot is overloaded by mishandling, which provides a safeguard for the operation. (Jam Press/Zhejiang University)
