Air propelled heart pump

Developers of a pneumatically operated heart catheter pump claim the device could be used as a safer alternative to the electric heart pump.

The device has been created by researchers at the Vienna University of Technology (TU Vienna) to temporarily help the human heart pump blood after a heart attack or an operation.

The new system is expected to help counter problems caused by the overheating of electric motors that are in common use inside the body. This can result in damage to the blood leading to blockages of the artery that could, in the most severe cases, contribute to organ failure.

Margit Gföhler, project manager and associate professor at TU Vienna, said: 'The aim was to avoid haemolysis, which is always a risk when using electric pumps. Our design uses air propulsion that removes this risk and will hopefully act as a temporary solution for patients recovering from a heart attack or awaiting a transplant.'

The pump, which is around 5mm in length, consists of two separate parts that are divided by a magnetic bearing. On one side air propulsion is fed through a tube that drives a rotor. This rotor couples to a screw on the other side that works with the magnetic bearing to pump approximately 2.5 litres of blood around the body per minute.

While the mechanics of the device are proven, Gföhler said that the main difficulty will be in the development of components small enough to fit the model.

'Because the system and the amount of fluid used is so tiny you can't really calculate how much friction will have an influence,' she added. 'At the moment we have a prototype that is twice the size of our target model. Our calculations are based on approximations, but we're hoping to do clinical trials in the near future to better understand its efficiency.'

Gföhler said that using an air-powered device could pose a number of safety risks as leaked air bubbles in the bloodstream may prove fatal. To minimise this risk, the systems will be monitored by a number of sensors to measure the pressure and rotations of the pump.

Gföhler added: 'We hope that we can create a device that is easily implanted into a catheter and fits with existing systems and hospital procedures.' The team is in the process of writing a proposal to develop the device further. If funding is granted, Gföhler plans to test a working prototype on animals within the next two years. Further areas of research include its use alongside procedures such as balloon angioplasty, to increase and control the pressure of the system.

According to the European Society of Cardiology, cardiovascular disease causes 42 per cent of all deaths in EU countries and 49 per cent in the remainder of Europe.

Ellie Zolfagharifard