Gherardi, Alessandro
(2008)
A skin surface characterization system based on capacitive image analysis, [Dissertation thesis], Alma Mater Studiorum Università di Bologna.
Dottorato di ricerca in
Tecnologie dell'informazione, 20 Ciclo. DOI 10.6092/unibo/amsdottorato/1135.
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Abstract
During the last few years, several methods have been proposed in order to study and to
evaluate characteristic properties of the human skin by using non-invasive approaches. Mostly,
these methods cover aspects related to either dermatology, to analyze skin physiology and to
evaluate the effectiveness of medical treatments in skin diseases, or dermocosmetics and
cosmetic science to evaluate, for example, the effectiveness of anti-aging treatments. To these
purposes a routine approach must be followed. Although very accurate and high resolution
measurements can be achieved by using conventional methods, such as optical or mechanical
profilometry for example, their use is quite limited primarily to the high cost of the instrumentation
required, which in turn is usually cumbersome, highlighting some of the limitations for a routine
based analysis.
This thesis aims to investigate the feasibility of a noninvasive skin characterization
system based on the analysis of capacitive images of the skin surface. The system relies on a
CMOS portable capacitive device which gives 50 micron/pixel resolution capacitance map of the
skin micro-relief. In order to extract characteristic features of the skin topography, image analysis
techniques, such as watershed segmentation and wavelet analysis, have been used to detect the
main structures of interest: wrinkles and plateau of the typical micro-relief pattern. In order to
validate the method, the features extracted from a dataset of skin capacitive images acquired
during dermatological examinations of a healthy group of volunteers have been compared with
the age of the subjects involved, showing good correlation with the skin ageing effect. Detailed
analysis of the output of the capacitive sensor compared with optical profilometry of silicone
replica of the same skin area has revealed potentiality and some limitations of this technology.
Also, applications to follow-up studies, as needed to objectively evaluate the effectiveness of
treatments in a routine manner, are discussed.
Abstract
During the last few years, several methods have been proposed in order to study and to
evaluate characteristic properties of the human skin by using non-invasive approaches. Mostly,
these methods cover aspects related to either dermatology, to analyze skin physiology and to
evaluate the effectiveness of medical treatments in skin diseases, or dermocosmetics and
cosmetic science to evaluate, for example, the effectiveness of anti-aging treatments. To these
purposes a routine approach must be followed. Although very accurate and high resolution
measurements can be achieved by using conventional methods, such as optical or mechanical
profilometry for example, their use is quite limited primarily to the high cost of the instrumentation
required, which in turn is usually cumbersome, highlighting some of the limitations for a routine
based analysis.
This thesis aims to investigate the feasibility of a noninvasive skin characterization
system based on the analysis of capacitive images of the skin surface. The system relies on a
CMOS portable capacitive device which gives 50 micron/pixel resolution capacitance map of the
skin micro-relief. In order to extract characteristic features of the skin topography, image analysis
techniques, such as watershed segmentation and wavelet analysis, have been used to detect the
main structures of interest: wrinkles and plateau of the typical micro-relief pattern. In order to
validate the method, the features extracted from a dataset of skin capacitive images acquired
during dermatological examinations of a healthy group of volunteers have been compared with
the age of the subjects involved, showing good correlation with the skin ageing effect. Detailed
analysis of the output of the capacitive sensor compared with optical profilometry of silicone
replica of the same skin area has revealed potentiality and some limitations of this technology.
Also, applications to follow-up studies, as needed to objectively evaluate the effectiveness of
treatments in a routine manner, are discussed.
Tipologia del documento
Tesi di dottorato
Autore
Gherardi, Alessandro
Supervisore
Dottorato di ricerca
Ciclo
20
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
skin capacitance skin ageing pattern recognition image analysis
URN:NBN
DOI
10.6092/unibo/amsdottorato/1135
Data di discussione
10 Aprile 2008
URI
Altri metadati
Tipologia del documento
Tesi di dottorato
Autore
Gherardi, Alessandro
Supervisore
Dottorato di ricerca
Ciclo
20
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
skin capacitance skin ageing pattern recognition image analysis
URN:NBN
DOI
10.6092/unibo/amsdottorato/1135
Data di discussione
10 Aprile 2008
URI
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