Breathe easy

An inhaler that monitors the amount of drug taken by a patient, and warns when they have not taken enough, could be used to treat asthma and cystic fibrosis sufferers, as well as improving pain relief and vaccines.

The inhaler, which contains specially developed sensors and controls to monitor and manage the amount of drug inhaled, is being produced by a UK consortium including Loughborough, Bath and Southampton universities. The device also transmits information to the patient’s doctor.

The inhaler could provide more accurate treatment for asthmatics and those with other lung conditions, cystic fibrosis sufferers and diabetics. It could also improve the transmission of anaesthetics, said Prof Peter Smith, head of the electronic and electrical engineering department at Loughborough.

Inhalers, which direct drugs to the bloodstream via the lungs rather than through the stomach as pills do, offer faster and more effective treatment. When tablets are swallowed a great deal of what is often an expensive drug is destroyed by the stomach, so only a percentage reaches the bloodstream.

But treating conditions such as diabetes with an inhaler, rather than by injection, requires a device with very strict levels of control, said Smith.

‘We need a system that is able to control the device, and includes actuators, sensors and some kind of feedback from the patient to detect whether or not the drug has been delivered properly. You then need an interface to deal with all this information and communicate it to the doctor.’

Failure to take medication, or not taking it as prescribed, is potentially fatal for patients and is a particular problem among the elderly and children.

But the amount of drug inhaled can also be affected by too much moisture in the air, and by the design of the device itself, as powder can become trapped in corners, said Smith.

‘On a particular activation, if the patient only gets 75 per cent of the prescribed drug it is OK, but if it is down to 25 per cent, the advice would be to take another shot.’

The information will also be collected and sent to the patient’s doctor via an electronic patient record. ‘We are not going to end up with something that looks like a mobile phone but is also an inhaler. But that is the concept,’ said Smith.

The project is being funded by the EPSRC, device makers Vectura and Bespak, and electronic patient record developer CSW Health.

A clinical trial, to be run by Southampton NHS Trust, is planned for next summer.

The sensors will be used to monitor the amount of drug emitted by the inhaler in each dose, to ensure this does not vary significantly. As the drug is transmitted as a cloud of powder, the sensors will also ensure this cloud is fine rather than lumpy and coagulated.

The sensors could also be used in other areas where aerosol analysis is undertaken, such as contamination monitoring in the workplace, said Smith.