Effects of cigarette smoking on the skin of women.
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Adult↗
Biomedical subjects
Jean-Marie Sainthillier
Publications and source records attributed to Jean-Marie Sainthillier.
Development of a new sensor based on micro-electro-mechanical systems for objective in vivo measurement of the cutaneous temperature: application to foundations.
BACKGROUND/AIMS: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro-electro-mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made-up skin. METHODS: Sixteen female subjects divided into two different age groups (18-35 and >50 years old) were recruited for this study. Several zones of the face and forearms were made up at random with foundations containing or not a thermoregulator raw material. The quantity of foundation applied on the skin was standardized and measurements were carried out first before make-up, and then 10 s and 5 min after make-up. The new sensor and the thermocouple were used successively on each zone. The cutaneous temperature was expressed in degrees celsius. RESULTS/CONCLUSION: The two systems are similar in terms of repeatability and reproducibility, with some differences in sensibility. The data measured by the MEMS sensor appear lower than those measured by the thermocouple. After make-up, the MEMS sensor detects a progressive increase of the temperature in time whereas the thermocouple detects a decrease. We found the same evolution on the face but in a more attenuated way. These results tend to show that the devices do not measure the same phenomenon. The thermocouple appears more sensitive to the thermal response of the made-up surface whereas the MEMS sensor appears more sensitive to the heat transfers in the interface between the skin and make-up.
Adult↗
Age-related changes of the cutaneous microcirculation in vivo.
BACKGROUND: The architectural frameworks of the skin microcirculation are rather complex and change continuously with aging. But these changes are yet poorly documented in vivo. OBJECTIVES: Using non-invasive methods belonging to the field of biometrology, the study aimed to investigate quantitatively the changes of the cutaneous microvasculature in different anatomic sites with age. METHODS: Measurements were performed on crow's feet, forehead, volar forearm and dorsum of hand in 50 women (aged 20-74 years who consisted of 10 probands in each live decades). The superficial vascular plexus was scanned by videocapillaroscopy and assessed with the software Capilab Toolbox. The subpapillary vascular plexus was explored with laser Doppler flowmetry. The skin color a* was analyzed by chromametry. RESULTS: A marked site and age effect on the skin microcirculation has been demonstrated. The density of capillary loops in the eldest group decreased by about 40-70% compared with the youngest group whereas the vascular length increased by 35-156%. The capillary density in the back of the hand was 4 times higher than in the crow's feet. The vascular length in the crow's feet was 3 times longer than in the back of the hand. Both blood flow and skin redness (a*) increased also with age. CONCLUSION: Both morphology and quantification of the cutaneous microvasculature showed changes with site and age. Videocapillaroscopy associated to an image processing and laser Doppler flowmetry revealed different vascular layers. So the combination of both instruments offers an easy way to observe the architectural frameworks in vivo.
Adult↗
Capillaroscopy and videocapillaroscopy assessment of skin microcirculation: dermatologic and cosmetic approaches.
BACKGROUND: Different noninvasive bioengineering techniques exist to study the microvasculature of the skin and the dynamics of the microcirculation. The goal of these techniques is to visualize the skin capillary circulation easily and directly. Indeed, this information is irreplaceable to study the physiology and physiopathology of the skin capillary circulation efficiently. AIMS: Capillaroscopy and video-capillaroscopy techniques are presented with different methods to study the capillary structure of the skin. METHODS: The methods presented in this work include image processing analysis combining morphology, statistics, geometry, and neural network detection designed to quantify the microcirculation and to follow its evolution. To illustrate the combination of these techniques and methods, different examples of their application are described, in dermatology (hypertension, venous insufficiency, age-related changes) as well as in cosmetology (rosacea and erythrosis assessment). CONCLUSION: The determination of structural or dynamic changes in the cutaneous microcirculation belongs to the noninvasive techniques of the biometrological domain. Thus, every capillary modification resulting from topical cosmetic products, or chemical agents can be observed. In pathology, numerous conditions can be better examined with this system. Associated with the potential of numerical image analysis, capillaroscopy techniques will probably extend their application fields to the assessment of the influence of arterial and venous diseases on the skin nutritional circulation.
Journal Article↗
Skin capillary network recognition and analysis by means of neural algorithms.
BACKGROUND: The intra-dermal capillary network can be easily assessed by a computerized videomicroscope system. Nevertheless, finding capillary loops automatically in an image is a difficult yet important first step in order to achieve microcirculation analysis. METHODS: A detection system was tested by combining videocapillaroscopy and principal component analysis (PCA). Our goal was to build a generic detector of capillary associated with a retinally connected neural network filter. The filter examines small windows of an image, and decides with this detector whether each window contains a capillary or not. RESULTS: Comparisons with manual detections showed that the system has a detection rate of 82% on test set A containing 100 good-quality images of the scalp. A detection rate of 65% was obtained on test set B containing 50 images with noisy background and large artifacts. The performance was increased by a color detector with a detection rate of 71% on the last test. These results correspond to a false detection rate lower than or equal to 10%. CONCLUSION: This neural filter system is capable of real-time processing; it recognizes capillaries anywhere in an image, and operates successfully under wide range of lighting and noisy conditions.
Algorithms↗
Geometrical capillary network analysis.
BACKGROUND: Skin microcirculation, especially the superficial network, can be assessed by a computer capillary video microscope system. The study of morphology and dynamics of microcirculation must include all dynamic and cooperative processes between the capillaries. For characterizing capillary ensembles, the statistical and geometrical properties of the network need to be explored. METHODS: The microvaculature of the skin and the microcirculation were investigated by combining videocapillaroscopy (VCP) and image processing techniques based on computational geometry and graph theory. Our goal was to characterize the capillary network in noisy pictures of the scalp. Different geometric methods were developed, based on proximity parameters (distance and surface) in order to circumscribe and construct this network. RESULTS: By studying the distribution of these parameters, extreme values or outliers, which usually correspond to artifact subregions in the pictures could be eliminated. Different algorithms were developed and has been implemented in an image processing software (Capilab Toolbox). CONCLUSION: This computerized system is capable of real-time processings, increasing the quality of videocapillaroscope images and minimizing the disturbance of artifacts. The algorithms presented here are easy to implement and can process any kind of images of the skin, even in the scalp. In association with an example-based detection system, this method can be generalized to other stimuli in the same conditions.
Capillaries↗