Biomedical subjects

V K Hughes

Publications and source records attributed to V K Hughes.

3 recordsLinked to original sources

PubMed2005

Alternative light source (polilight) illumination with digital image analysis does not assist in determining the age of bruises.

The age of a bruise may be of interest to forensic investigators. Previous research has demonstrated that an alternative light source may assist in the visualisation of faint or non-visible bruises. This project aimed to determine if an alternative light source could be utilised to assist investigators estimate the age of a bruise. Forty braises, sustained from blunt force trauma, were examined from 30 healthy subjects. The age of the bruises ranged from 2 to 231 h (mean = 74.6, median = 69.0). Alternative light source (polilight) illumination at 415 and 450 nm was used. The black and white photographs obtained were assessed using densitometry. A statistical analysis indicated that there was no correlation between time and the mean densitometry values. The alternative light source used in this study was unable to assist in determining the age of a bruise.

Adolescent↗

PubMed2004

The perception of yellow in bruises.

For forensic purposes, the presence of the colour yellow in a bruise may be regarded as indicating it is not recent. However, a previous study has shown that observers may disagree in their description of the colours in a bruise. This study was designed to determine how consistent observers are in perceiving the presence of yellow. Subjects were shown a series of photographs of a bruise that had been digitally modified (Adobe Photoshop) to contain amounts of yellow that increased from 2% to 20%. The point at which subjects first perceived the colour yellow was recorded. The perception threshold for yellow ranged from 4% to 16% (mean=8.7%, median=8%) in the 50 subjects that had normal colour vision. Statistical analysis indicated that an individual's yellow perception threshold increased by 0.07% each year, but gender had no effect. The results reveal that there is variability in the perception threshold for yellow in the general population and that a subject's ability to perceive yellow in a bruise declines with age.

Adult↗

PubMed2004

The practical application of reflectance spectrophotometry for the demonstration of haemoglobin and its degradation in bruises.

AIMS: To develop a non-invasive method to demonstrate the presence of haemoglobin and its degradation products in bruises in live human subjects for the purposes of objectively assisting in the determination of the age of a bruise. METHODS: The cuvette holder unit of a Cary 100 Bio UV-Visible Spectrophotometer was replaced with the manufacture's fibre optic cable and optical reflectance probe. The probe was placed on the skin surface. The absorption spectrum from 780 to 380 nm was collected and transformed into the first derivative. Calculation of the first derivative permits absorption attributed to haemoglobin degradation (primarily to bilirubin, but also haemosiderin) to be separated from absorption by haemoglobin. First derivative and colorimetry values, expressed as CIEL*a*b data, were derived from scans of 50 bruises. RESULTS: The fibre optic cable and probe allowed the spectrophotometer to collect reproducible absorption spectra of bruises in the skin of living subjects. A bruise at three days has greater negative first derivative values at 480 and 490 nm than does a fresh bruise, indicating the local degradation of haemoglobin. Correlation between the first derivative and the CIEL*a*b "b" values in a series of bruises indicates that the yellow colour in a bruise is proportional to the amount of local haemoglobin breakdown. CONCLUSION: The ability to demonstrate the presence of haemoglobin and measure its degradation in bruises in living human subjects by a non-invasive method has not been described previously, and may be of use in the objective ageing of bruises for forensic purposes.

Bilirubin↗