Engineering better medical sensor technology

09 June 2016

Bioengineers at the University of Canterbury are working with St George's Hospital and the Canterbury District Health Board to speed up sepsis detection in the ICU.

Engineering better medical sensor technology

UC Mechanical Engineer Dr Chris Pretty (left) and Dr Geoff Shaw, an Intensive Care specialist and co-investigator in the study, demonstrate how the non-invasive sensor technology is used to pick up the venous oxygen saturation signal.

Engineers at the University of Canterbury are working with St George’s Hospital and the Canterbury District Health Board to speed up sepsis detection in the Intensive Care Unit (ICU).

By modifying existing technology and using it in a new way, University of Canterbury (UC) bioengineers have been able to pick up an additional oxygen saturation reading that could provide an early indication of sepsis.

Mechanical Engineer Dr Chris Pretty, from UC’s College of Engineering, says existing non-invasive sensor technology has been repurposed to pick up the venous oxygen saturation signal, normally obtained via invasive blood sampling.

“This real-time measurement could solve a problem for clinicians, enabling them to identify and treat conditions, such as sepsis, earlier.”

Sepsis results in poor oxygen extraction from the blood. Standard pulse oximeters, which attach to a patient’s finger, only offer arterial oxygen saturation readings. By attaching a low pressure cuff around the top of a patient’s finger and employing sophisticated signal processing and control, Dr Pretty and co-researchers can also obtain venous oxygen saturation readings.

“Knowing both the arterial and venous saturations, and how they change, will enable earlier diagnosis and lead to better patient outcomes,” Dr Pretty says.

He and his UC colleagues have a longstanding relationship with Dr Geoff Shaw from the Canterbury District Health Board. This has led to an increasing amount of work at St George’s Hospital, which has a strong interest in advancing ICU research.

Dr Pretty says that having access to hospital facilities enables researchers to solve problems more quickly, assisting developments to make a difference in the ICU sooner.

“It is a rare and valuable opportunity to conduct applied research in a real clinical setting. St George’s has provided significant research support to see this project to this point. This has been critical and highly welcomed.”

The project is progressing well and the next stage will involve trialling the device on real patients at both Christchurch and St George’s Hospitals.

The relationship with Christchurch and St George’s Hospitals has also inspired other joint applied-research projects to improve outcomes for patients, says Dr Pretty.

For further information please contact:

UC Senior Lecturer Dr Chris Pretty, Mechanical Engineering, University of Canterbury
Ph: (03) 364 2987 ext 7238,


Margaret Agnew, Senior External Relations Advisor, University of Canterbury
Ph: (03) 364 2775 | Mobile: 027 5030 168 |
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