In 2014, medical device startup Sutrue first began developing a 3D printed suture stitching device that could help prevent needle stick injuries. Medical stitching by hand is tricky, because it relies on the practitioner’s ability, alertness, dexterity, and training, and hasn’t changed much over the years. Alexander Berry, the company’s director and product designer, and the rest of the Sutrue team used 3D printing and CAD technology to develop the automated surgical suturing device.
There have been over 10,000 patent attempts to make a suturing device, and Sutrue was the first company to successfully create one. In September, Sutrue had reached the demo stage of an endoscopic version of the device, and now the company has announced two new automated devices – an Endoscopic/Robotic Suturing Device and a Handheld Suturing Device. According to Berry, rapid prototyping was a key factor in the development process.
“Rapid prototyping has significantly reduced the cost of the creation of the devices, probably by a factor of 50. It has also shaved years off the time it would have otherwise taken. We’ve taken a ‘create, print, test, tweak, reprint’ approach to solving the problem,” Berry explained. “We even coined our own term for the working process and called it ‘Multi-typing’, which is the ability to loosely design the same component in three or four different ways, have them printed within a few hours and then test and learn from each prototype. This approach has been instrumental in allowing a small start-up company like ours to maximise our output in terms of creativity and problem solving.”
The two patented devices help lower the margin for human error by changing the manual stitching process into a quicker and more accurate automated one. Additionally, both the Handheld Suturing Device and Robotic/Endoscopic Suturing Device have the potential to majorly reduce costs for the NHS.
The devices can each produce a row of sutures, sew around a corner, and tie a knot. The Handheld device features an increased needle force and the ability to use standard suturing needles from multiple suppliers, while the Endoscopic/Robotic device, in contrast with the use of forceps during robotic surgery, offers increased suture speed and accuracy and less open operations, with an uptick in minimally invasive keyhole surgeries.
Sutrue has worked with Richard Trimlett, a cardiothoracic surgeon and the Head of Mechanical Support at London’s Royal Brompton Hospital, for nearly a decade; last summer, the startup and Trimlett developed a metal 3D printed heart stabilizer for use in delicate keyhole operations. Trimlett also helped Sutrue create its newest 3D printed devices.
“It’s true to say that the majority of operations we’re doing today are still open and that’s not because the patient wants them open, it’s because of the limitations of the technology and so there are many improvements to technology that we need to get to the point where we can do everything as a keyhole operation and I see this as one of them,” said Trimlett, who believes the Endoscopic/Robotic Suturing device could help influence the future of robotic surgery.
The Endoscopic/Robotic device has applications in all forms of robotic surgery, but particularly in the cardiac, cranial, gastrointestinal, and thoracic areas, while the Handheld version is best suited for use in field hospitals, extreme environments (like outer space), and the dentistry, veterinary, textile, and manufacturing industries.
“[The Sutrue handheld device] is less likely to cause tissue damage and inexperienced operators often cause tissue damage without realising it, particularly in general surgery for example, whilst doing routine parts of general surgery, like closing the wound and the layers of the wound,” said Professor John Pepper OBE, Professor in Cardiothoracic Surgery at the National Heart and Lung Institute, who helped Sutrue develop the 3D printed suturing devices. “It’s important, yet often delegated to the most junior person and tissue damage there can lead to wound breakdown, infection, haematomas and so on.”
The head of the handheld device can rotate and pivot softly and precisely to find the area that needs to be sutured, thanks to a complex miniature gear mechanism driving the needle. Each stitch can be performed with reproducible accuracy, and users can achieve up to three rotations of a needle per second, rather than one stitch every 25 seconds when suturing by hand.
Spanning over 15,000 hours of design work, Sutrue made 38 different prototypes of the automated suturing devices, and designed and tested over 1,500 parts. While this may sound like a long time, it would have been even longer had it not been for 3D printing. The startup works with Concept Laser, a GE Additive company, to 3D print small, detailed parts for the devices, including the 0.4 mm long teeth for the gear mechanism, 3D printed using stainless steel 316L.
Stephan Zeidler, the Business Development Manager for the medical sector at Concept Laser, said, “By using the high-resolution capabilities of our Mlab cusing R 3D printer, Sutrue has been able to successfully speed up the engineering process involved in the creation of their medical devices, through a process called Rapid Prototyping.
“Once designed by Sutrue, the structurally superior parts were printed by our team before Sutrue assembled them into numerous medical prototypes – sometimes straight from our printer with minimal post processing. This in turn saved considerable time and cost and has resulted in the completion of a series of fully-functioning medical prototypes. Sutrue’s success in having achieved this is a fantastic example of what is possible with our DMLM machines and additive manufacturing technology. We are delighted that both devices are now mechanically sound and are ready for testing within medical industry.”
3D printing makes it possible to achieve otherwise impossible geometries, as well as create parts at less cost with higher performance capacity, which Berry stated is usually “what the surgeon was previously lacking.”
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