Ambulatory Sub-Bandage Pressure Assessment: Background and implementation

Abstract

Venous leg ulcers are recognised as a major health care problem that has significant cost implications for health services as a well as quality of life issues for sufferers. This thesis presents work undertaken towards the assessment and monitoring of ambulatory sub-bandage interface pressures, on healthy volunteers and patients, as the basis for more in-depth future studies.The projected study required a literature review concerning the socio-economic aspects, aetiology and healing methods (focusing on compression therapy) of venous leg ulcers, interface and stiffness measurement studies, and contemporary pressure measurement technologies. Gaps in knowledge relating to the effects of walking speed on sub-bandage pressures and the variation of dynamic stiffness indices during movement were identified. The planned outcome was the specification and development of an electronic measurement instrument capable of monitoring sub-bandage pressure during ambulation. This is described as the Wound Assessment Laboratory in this thesis.Such a system was designed and developed and provided an array of 10 pressure sensors and 4 gait indicators. This system was battery powered and allowed wireless transmission of pressure transducer data to a portable computer for analysis and display. The system performed well when tested for linearity, hysteresis, repeatability, noise, drift and crosstalk effects. Due to time constraints and practical issues that are discussed in the thesis, however, it was not possible to completely validate the system in a clinical laboratory context. Consequently, further future investigations are recommended that should include studies involving human volunteers and patients, with the aim of monitoring and characterising subbandage force distributions and dynamic stiffness indices at various walking speeds