A wound infection monitoring system

Infection control is a key aspect of wound management strategies. An infected wound results in chemical imbalances in the wound and may lead to prolonged healing times and wound surface degradation. Wound dressings changes may result in damage to healing tissues and an increased risk of infection. This thesis presents details of a measurement system based on sensors that can be placed at the wound-dressing interface and potentially monitor the bacteria in real time. Two systems were developed, one to grow bacteria in suspension and the second to encourage biofilms to grow on the electrode surfaces. Both systems allow the electrical impedance to be measured and were used to evaluate the impedance characteristics of bacterial growth with two sensor materials, silver-silver chloride and carbon. The bacteria Staphylococcus aureus and Staphylococcus epidermidis were selected as species commonly isolated from wounds. The growth of bacteria was confirmed by plate counting methods from the suspensions and by microscopy staining techniques of the biofilms. The impedance data was analysed for discernible differences in the impedance profiles to distinguish the absence and/or presence of bacteria. Equivalent circuit modelling was performed to provide further information on the physical processes occurring within the systems. The main findings were that the impedance profiles of silver-silver chloride sensors in bacterial suspensions could detect the presence of high cell densities. However, the electrodes tended to inhibit the growth of bacteria and also prevented biofilms forming on the electrode surfaces. The Staphylococcus aureus strains adhered to the carbon sensors and in at least one strain the impedance profiles had discernible differences. All the strains with carbon sensors produced noticeable differences in the equivalent circuit model analysis. These results show that there is potential to create a real-time infection monitor for wounds.

Name dc:type.qualificationname

engd

Level dc:type.qualificationlevel

doctoral-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

2010

Author dc:creator

• Farrow, Malcolm

DOI

10.48730/adjn-w723

Identifier

T12941

OAI identifier oai:identifier

oai:strathclyde:kk91fk644