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J M Melhuish

Publications and source records attributed to J M Melhuish.

4 recordsLinked to original sources
PubMed2004

Measurement of the skin microcirculation through intact bandages using laser Doppler flowmetry.

The microcirculation under compression bandages has been assessed by numerous methods; however, the measurement techniques can disrupt the bandage-skin interface, affecting the measurement. In this study, a non-invasive method for measuring cutaneous blood flow using laser Doppler flowmetry (LDF) is presented. Ten volunteers had their microcirculation assessed by a laser Doppler probe being placed on their upper forearm with and without a light-transmissive gel and with a compression bandage plus light-transmissive gel. A circulatory challenge to the bandaged forearm in two of the volunteers was also undertaken. The median (95% confidence interval) perfusion (p.u.) for the skin surface was 24 (15-33) perfusion units (p.u.), and the skin plus light-transmissive gel demonstrated a higher perfusion: 66 (50-82) p.u., (p < 0.012). The addition of the compression bandage, with additional gel allowed to permeate through to the underlying skin, decreased the perfusion to 27 (20-34) p.u. (p < 0.007). In both volunteers, the microcirculatory flow responded to the vascular challenge, resulting in flow changes related to the cuff pressure (45-27 and 14-8 p.u.). This method demonstrated that it may be possible to assess the microcirculation through intact bandages, without the need to place any sensors at the skin-bandage interface.

Adult↗
PubMed2000

The physics of sub-bandage pressure measurement.

Compression therapy is the principal treatment for leg ulcers associated with venous disease. The extent of compression generally can be estimated from the general Laplace equation relating pressure, bandage tension and leg radius. This study aimed to investigate the physical forces under long stretch bandages applied under constant tensions to cylinders of three defined radii ('model limbs'). Force expressed as pressure was measured under one, two and three layers of eight long stretch bandages and a plastic film (control) using temperature-compensated, strain-gauge pressure transducers. The bandages were applied at the manufactures' recommended extensions/tensions and at constant tensions (2-10N) to three rigid plastic tubes of increasing size, covered with a layer of soft foam. Foams of different hardnesses ranging from 20 to 230N were assessed. The median applied pressure and observed bandage characteristics changed with bandage type. The median applied pressure also changed with tension, number of layers, tube radius and foam hardness. The inter-layer shear component also tended to increase with the number of layers. An increase in sub-bandage pressure was observed relative to the radius, tension, foam hardness and number of layers but the relationship was not directly proportional. The shear force tended to be associated with increased bandage layers.

Bandages↗
PubMed1994

Methods of measuring wound size: a comparative study.

The lack of an accepted method of accurate and objective measurement of wound dimensions is a major obstacle to the assessment of effective wound management regimes. This study compares three different wound volume measurement techniques (filling the lesion with saline, molding of a dental impression material and a computer vision method based on image processing and the Structured Light technique) in terms of accuracy, precision and practicability in a clinical environment. Three groups of hospital staff, doctors, nurses and technicians, repeatedly measured a set of 6 different models of wounds. Measuring wound volume by filling it with saline produces results with standard deviations between 9 percent and 18 percent of the actual volume. Dental impression material performs better, between 5 percent and 16 percent, but is difficult to apply and time consuming to use. Apart from the advantage of providing instant optical records of wounds, the image processing method produces more reliable volume measurements with a standard deviation of between 3 percent and 15 percent. The results demonstrate that the computer based method yields the most reproducible results with a minimum of inter-observer error but the method is not applicable for undermined, very deep and very large wounds.

Anthropometry↗