Architects develop trachea stent prototype

Two architects have created a prototype stent for use in the trachea called the Shell Lace Stent.

Mike Tonkin and Anna Liu have developed and prototyped the device using digital design software and 3D-printing technologies commonly used for architecture projects.

The stent is a new type of shell lace structure – the practice’s signature single-surface structural technology designed and developed through a decade of research for architectural and engineering applications.

Tonkin Liu’s shell lace structure uses biomimicry to abstract principles from natural structures such as molluscs and plants and have been working with engineers Arup and scientists from the Natural History Museum.

Since 2008, the technology has been used in the design of ultra-lightweight pavilions, bridges and towers, and to create a medical device.

Tracheal stents are commonly used to support transplants of the trachea and to treat collapsed airways in instances of throat cancer, trauma (e.g. car crash victims) and for the elderly. Stents are typically manufactured as a non-tailored tubular mesh. Tonkin Liu’s stent design is c-shaped rather than tubular, with the aim of adapting better to the unique physiology of each patient. The device is designed to be manufactured from medical grade silicon, with a perforated surface allowing for breathability and drug-delivery to the trachea tissues.

The stent is inserted in its inverted position, and then unfurled to provide a flexible and strong fit, with a natural outward pressure that lessens the risk of migration – a feature that the architects designed after analysing the geometric principles of Calla Lily petals.

In 2014, Tonkin Liu published a book entitled The Evolution of Shell Lace Structure to coincide with an exhibition of all their Shell Lace projects to date at the Royal Institute of British Architects. During a talk the architects gave in the exhibition programme, a clinical research scientist questioned whether the structural technique could be applied to the design of a small medical device, and soon after the practice’s quest to collaborate with the medical profession began.

Obtaining funding from government-backed agency Innovate UK in 2016, the practice set about creating prototype stents using 3D printing. To be suitable for medical use, the resulting Shell Lace Structure was 500 times smaller than those previously created for any architectural applications.

Partner Mike Tonkin commented: “This project is small in scale but grand in ambition. It demonstrates how architects can apply themselves beyond architecture – how we can design things other than buildings. We hope now to bring the Shell Lace Stent to manufacture and we can design things other than buildings. Our aim is now to bring the Shell Lace Stent to manufacture stage and see it bring tangible benefits to patients globally.

“We need to collectively reimagine the role of the architect – the architecture sector has great potential to engage with different realms and professions. As we all live longer and make greater demands on the medical profession, we should all look to use what skills we have (in our case advanced digital design and fabrication) to collaborate and benefit society.”

With its innovative inverted surface and structure and other novel features, the prototype has drawn excitement from leading medical experts. Professor Martin Birchall, UCL Professor of Laryngology and Consultant in ENT Surgery at the Royal National Throat, Nose and Ear Hospital heralded it as “a remarkable and unprecedented stent invention, that is ground-breaking in the context of currently available devices.”

Following numerous design iterations and successful testing, the Shell Lace Stent has now been approved as patent pending. Tonkin Liu are working with research partners and medical experts to bring the innovation to market, as well as exploring broader applications of the technology for other parts of the human body.