Browsing by Person "Abboud, R."

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A modular device to measure the effects of plantar foot pressure on the microcirculation of the heel
(Elsevier Science Ltd, 2003-03) Santos, Derek; Carline, Tom; Richmond, R.; Abboud, R.
Background: Past research has concentrated on foot function and plantar foot pressure, with many devices developed for this purpose. However, little is known of how cutaneous blood flow compensates for ambulatory repetitive circulatory insults and how ulceration occurs. Objectives: To develop a system to measure the effects of plantar foot pressure on cutaneous blood flow in the supine and semi-weight bearing positions. Method: A system was developed that integrated a laser Doppler fluxmeter with a pressure probe, allowing plantar foot pressure and skin blood flow to be recorded simultaneously. The system was tested using four volunteers (288.6 years). Results: A significant difference existed between baseline laser Doppler flowmetry (LDF) in the supine and semi-weight bearing positions (P=0.023). Differences between both positions also existed in the reduction in LDF levels following application of pressure (P=0.015), the maximum hyperaemic response (P=0.034) and time taken to reach maximum hyperaemic response (P=0.019). Conclusion: The device has shown that with current technology it is now possible not only to investigate plantar foot pressure but also how it affects skin blood flow, which in some cases can lead to ulceration. The effect of plantar foot pressure on cutaneous blood flow differs depending on whether the subject is supine or semi-weight bearing. Thus, to understand the effects of plantar foot pressure on skin blood flow future researchers must ensure that subjects are in an upright position when recording.
A review of the effects of external pressure on skin blood flow
(Elsevier, 2003-12) Santos, Derek; Carline, Tom; Richmond, R.; Abboud, R.
The human foot is a complex mechanical structure consisting of bones, ligaments and joints. They act together to provide a robust system capable of absorbing and dissipating the intermitted pressure that is subjected to its plantar surface during walking to prevent soft tissue breakdown. Current studies suggest that plantar foot pressure may lead to soft tissue breakdown (e.g. neuropathic ulceration) and hence research has so far concentrated on investigating the mechanical effects of plantar foot pressure on the foot's integrity. This has been possible through the widely available pressure and force platforms as well as in-shoe pressure systems. However, to understand how plantar foot pressure causes soft tissue breakdown it is vital to investigate both the physiological-mechanical interactions between the skin and plantar foot pressure. This review suggests that with the current advances in technology, the physiological response of skin blood flow to mechanical plantar foot pressure should be investigated and correlated further, both during static and dynamic loading, by developing a new system capable of either measuring both variables simultaneously or by synchronising two systems in real time.
Vascular assessment of microcirculation in lower limb wounds
(2012-04) Flynn, Lynne; Abboud, R.; Khan, F.
A good blood supply is paramount to initiate healing of lower limb wounds regardless of whether these are in an acute or a chronic phase, and it is vital that the method chosen for vascular assessment is accurate, user friendly and if possible non invasive. Several methods of vascular assessment are currently available for both clinical as well as research use. Included in this review are laser Doppler flowmetry and perfusion imaging with the utilisation of iontophoresis and reactive hyperaemia, laser speckle contrast imaging, photoplethysmography, thermal infra red imaging, transcutaneous oxygen tension as well as the ankle brachial pressure index and nailfold capillaroscopy. Although the techniques function in a variety of ways, the measurements offer an understanding of the role of microvasculature and endothelial function in the development of lower limb ulcers, as well as in wound assessment and the determination of the possibility of healing as an outcome of management strategies. This review outlines the techniques for assessment and given the important role microvasculature plays in the repair and healing of wounds, examines the available evidence for the role of the various measurements in this process.