Disposable pump accurate to 1%

A low-cost disposable plastic pump, shown as a demonstration idea at a medical show earlier this year, has now a fully functioning device – with a graphical user interface – for intravenous infusion applications. The ‘Secta’ pump is the brainchild of Paul Pankhurst, chairman of design consultancy PDD Innovations. It has a rotating plastic rotor with four chambers and an elastomeric diaphragm that enables pumping of 2 microlitres to 30ml per minute to an accuracy of {{plus/minus}} 1%. It is suitable is applicable to pumping any kind of fluid with viscosities up to 100cp at low pressures. The example seen by Eureka had a circular rotor with four flats to form the cavities as it turned within its circular housing. The clever part was the elastomeric diaphragm between the output and input apertures that pressed against the rotor to prevent fluid being carried back in the cavities from the output to the input ports. The pump has attracted a £250,000 investment from the Capital Fund – the largest initial investment it offers – and the device has been on trial at St Bartholemew’s Hospital, London. It is made of polypropylene (PP) and a PP-based elastomer. The housing is made by two-shot injection moulding. It is just 22mm x 22mm and fully reversible. Back in February, the pump existed as a concept, but has moved rapidly forward. “We now have a fully functioning device as of two days ago,” says Pankhurst. “It has a new controller with a new user interface. It now exists as a non-regulatory device that demonstrates that is does exactly what we set out to achieve.” Using a graphic panel, it is possible to set up rate of flow, which can deliver that necessary rate and total volume to infuse. It also has air in-line sensing and upstream and downstream pressure sensing that detects occlusions. “As well as medical applications, sensing of occlusions or the pumping of air is also highly relevant to other possible non medical applications, such as the pumping of syrup in a drinks dispensing machine,” he says. Because it is disposable, the pump has applications in the food industry, where it could be used to pump foodstuffs from containers, guaranteeing high standards of food hygiene and reducing wastage – as suppliers could re-use the containers by fitting them with a new clean pump. In laboratories or the chemical industry, the pump could be used to pump soaps and disinfectants or hazardous materials. It could also be used as a fuel pump in small, petrol-powered appliances. Ian Cameron, investment director of the Capital Fund says: “PDD Innovations has created an innovative, disruptive pump technology that has huge potential for applications across a range of sectors. As well as enjoying a reputation for originality and innovation, PDD has significant experience in product development and medical technology, with a particular expertise in the IV infusion market.”