Visibility of standardized induced bruises under forensic light source compared to white light source.

Medical forensic experience indicates that visibility of bruises may be
improved when illuminated using forensic light sources.
However, limited research on this issue has so far been performed and
validation of this method is absent.
Forensic light sources are often utilized by police investigators and forensic
physicians, but usage can be increased when usage is scientifically proven.
Investigation into the visualisation of bruises using the standard equipment
used by forensic experts, photography with white light and 415 nm
illuminations, supported by the information from multispectral imaging at
wavelengths dedicated for the detection and analysis of bruises could
potentially result in an improvement of the visualisation of bruises.
Additionally, photography at the dedicated wavelengths can be used to give more
information about the development and age of a bruise. Information on the
development and healing of bruises can help to validate current and develop
future models for the age determination of bruises (Stam et al, 2011).

To assess visibility of standardized induced bruises using imaging
(photography) under white light, forensic light sources, and multispectral
scanning, at set time intervals.
To gain understanding in the influence of individual factors on bruising.

Healthy NFI-employees are asked to participate in the study by using flyers
that will be hung in the NFI building.

To induce bruises by a standardized blunt impact, a cylindrical metal object of
400 grams with rounded edges is dropped at random for 1 meter down a tube
halfway on the flexor side of the forearm.
(slightly adjusted method of Lombardi M, Canter J et al: Is fluorescence under
an alternate light source sufficient to accurately diagnose subclinical
bruising? J Forensic Sci 2015; doi 10.1111/1556-4029.12698).

lmpact sites are photographed using a standard DSLR camera when illuminated
with artificial white light (3900K), forensic light (415 nm) sources, and with
a multispectral camera at 8 wavelengths (450, 480, 509, 542, 558,578,620 and
850 nm) under illumination of a halogen light. Photographing is done before and
after impact, and at 6 hours, and 1, 2, 7, 14 and 21 days after impact (as long
as a bruise, with either method, is visible).

Each participant will fill in a questionnaire at the beginning of the research.
This form will contain questions about age, gender, sport activities and
medication. Measurements of the forearm will be taken (circumference, point of
centre, and thickness of the skin at the point of impact. This information will
be compared with the presence or absence of a bruise.

Assessment of bruise visibility will be performed by the researcher by making
paired comparisons of coded photographs. Development of the bruise and the
healing process will be analysed based on the change in size of the area
containing higher concentration of haemoglobin and bilirubin. The photographs
obtained with the multispectral camera are selected for the detection of these
chromophores. Spectral analysis will be performed to determine the change in
size of the haemoglobin and bilirubin area.

see above

Burden and risk in this research will be minimal. The weight of the cylindrical
object is based on other studies. In none of these studies severe injuries were
seen.
In our preliminary study (N=60) no adverse effects were seen:
Moderate pain at site of impact, during maximum 1 week.
Mean pain score after impact, in preliminary study: 3 out of 10.