UK Polyurethane Tooling and Moulding Expertise Aids Liver Transplant Device

Medical device development company, OrganOx, based in Oxford, UK, is using the tooling and moulding services of UK moulder Midas Pattern Company to help manufacture a new device that prolongs the life of livers outside the human body. The device, named metra (trademarked), enables the repair, preservation and objective viability assessment of livers prior to transplantation for up to 24 hours, using normothermic (normal body temperature) oxygenated blood. Midas supplies the panel upon which the device’s plastic disposables are mounted. Clinical trials involving metra are ongoing with European product release anticipated in early 2014.

For many years, the storage of livers in an ice box at 4˚C (39˚F) has aimed to minimise liver decay. However, despite this technology, liver preservation outside the body remains limited to around 12 hours maximum. OrganOx, a spin-out (founded in 2008) from the University of Oxford, sought to address this issue by creating metra, a device offering 24 hour preservation that aims to increase the number of livers available for transplant. The human body is mimicked by metra by continuously perfusing at physiological pressures and flows with oxygenated blood at 37˚C.

To bring this exciting new concept to reality, OrganOx has outsourced many aspects of the device’s manufacture. For the important panel that accommodates many of the device’s plastic disposables, the company’s R&D partner, Cambridge-based Team Consulting Ltd, recommended the services of moulding specialist, Midas Pattern Company. Midas offers a trademarked service called MRIM, the name given to the company's unique composite resin tooling system which is used to produce high quality polyurethane mouldings.

“A small number of the Midas panels have already been manufactured and are assembled on metra units undergoing clinical trials,” says Dr Colin Story, operations director at OrganOx. “We expect to produce further short runs over the coming months with production ramping up once the product is released in Europe next year.”

MRIM from Midas can be used for parts ranging in size from A4 up to 2.5 x 1.0 x 0.5 m. The most complex of mould tools can be produced, including square faces, undercuts, metal inserts and collapsible cores—all of which are guaranteed for up to 5,000 parts. Wall sections can vary in localised areas without the risk of sinking or distortion, so designing for MRIM can be simple or elaborate, in line with requirements. The minimised distortion is due to the low pressures used by the process, making it ideal for a multi-part assemblies such as metra where fitment build-up is critical.

Midas has manufactured the MRIM tooling and is producing the panel mouldings, which are supplied fully painted, allowing OrganOx to brand its product by matching corporate colours—Midas offer a huge variety of looks, colours and paint style options.

“Midas staff have been helpful, reliable and astute throughout,” says Dr Story. “We always know where we stand and have no complaints whatsoever. We have invested in the tool and will continue using Midas as we move through the various project stages.”

Like many manufacturers who require professionally moulded parts but in relatively low volumes, MRIM composite resin injection mould tools from Midas offer OrganOx a low cost entry to market. Furthermore, modifications for design changes and enhancements can also be completed cost effectively, making it possible to go straight to tooling without the need for expensive prototyping phases.