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Needle-less injections

Over 10 billion needle injections are given worldwide every year, yet they are disliked by most patients and are a safety hazard for patients and healthcare professionals. The idea of using needle-free injections has been around a long time, and indeed was used as long ago as the Second World War. The performance of a mass-produced disposable product , developed by Weston Medical, is being investigated in conjunction with researchers at CUED.

Needle-less syringe in use

Measuring the drug distribution using X-Ray computer tomography

Oliver Shergold, a PhD student working with Professor Norman Fleck, explains the issues:
"The needle-less syringe that has been developed by Weston Medical uses a compact nitrogen gas source to propel a pre-measured quantity of drug through the skin into the underlying tissue. The whole injection is complete in less than 100 milliseconds."

"The syringe squirts a very fine jet of liquid at sufficient pressure to penetrate tissue. The initial pressure has to be high to penetrate the skin, followed by a lower pressure to pump the drug in."

"There are two aspects to the research in which engineers are involved: one is to make an instrument that is both safe and effective when manufactured as a mass production item, and the second is to understand what is happening when the drug is injected. The second of these is a materials problem of the type engineers are used to, although in this case the materials in question are biological ones. We are aiming to develop both a mechanical model of the injection and an artificial model of skin, using rubber, to be used for the trials."

"We have to develop a good understanding of what exactly is happening during drug delivery, such as the effect of different parameters on the distribution of the drug into the tissue (size of orifice and pressure of delivery for example). To do this, we are using analytical techniques such as finite element analysis to model hole puncture and imaging techniques such as X-Ray computer tomography and the Stradx 3D ultrasound system to track the position of the drug after injection."

For more information, please contact Professor Norman Fleck, T:01223 332650