Development of a Measurement Instrument Using Capacitance Sensors Techniques to Image and Measure the Skin Surface Hydration

Studies have shown that capacitance sensors can be used for skin hydration imaging,
surface analysis and skin micro relief measurements. In this report, development of a
hardware measurement instrument and accompanying software that was made is
discussed. Work then focussed on stratum corneum (SC) dynamic water
concentration measurements using the capacitance sensor. To further validate the
measurement results, the capacitance sensors SC surface hydration results are
compared with the optoAthermal transient emission radiometry (OTTER) and transA
epidermal water loss (TEWL) results measured by using the condenserAchamber
TEWL method.
To achieve the aim of this project, a handAheld probe, based on the FingerPrint Card
area sensor development kit (FPCASMD 5410, FPCAAMD 6410 and then on the
FUJITSU MBFA200), has been developed and used in this research. The development
kit contains an array area sensor chip, a processor board and a serial/USB
connecting cable for connecting to a PC.
Dedicated JAVA, C++ and Mathworks MatLab programs have also been developed,
which can capture the images, process the images, perform grayscale value
calculation and display the images. A secondary program was developed in MatLab
that allows extraction of data from raw image files created by the sensor. These data
are then processed to show mathematical calculations and image profiling of the
subject skin site. Additionally, the MBFA200 sensor is able to record live video files of
the skin.
The precision of the resulting data is analysed and multiple experiments are
conducted to test the viability and usage of the capacitance sensor in different areas
of research such as skin hydration, occlusion, depilation and scar measurement.
Further test were also conducted on a multitude of hydrated surfaces both live an
nonAlive.