Believed to be the first of its kind in the world, the catheter is one of the new products being developed in the emerging field of bio micro-electro-mechanical systems, or BioMEMS, which have applications in the biomedical field.

The new catheter has many advantages over existing catheters, according to UniSA research fellow Dr Hung-Yao Hsu, who is developing the catheter with industry partner, the Women's and Children's Hospital (WCH).

"Current catheters rely on the transmission of pressure via water filled lumina to transducers external to the body. Each lumen is like a garden hose with water running through. If the outlet of the hose is blocked suddenly, the pressure inside will build up and generate a pressure wave back to the tap end of the hose where it can then be sensed. The working principle behind the existing water perfusion catheter is the same as the watering hose. Because fluid is always flowing, patients sometimes feel uncomfortable and turn their bodies over, which increases the risk of inhaling fluid into their airway," Dr Hsu said.

"Existing catheters also need to be recalibrated before each use, but posture changes, movement and fluctuation in the flow rate can cause variations in pressure, which mean that the accuracy of measurement cannot be guaranteed. In addition, dampening of the pressure signal leads to under-recording of peak swallowing pressures, so rapid pressure changes are not be picked up instantaneously and the signal may be missed, which could result in a wrong diagnosis being made.

"Another significant disadvantage of the catheters is that they are expensive and are often reused to cut medical costs. This carries a risk of transmitting
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Contact: Geraldine Hinter
geraldine.hinter@unisa.edu.au
61-883-020-963
Research Australia
6-Feb-2006