It's tough creating a model of neonatal skin!!

Making a Neonatal Skin model:

· Firstly we have an approximate skin model from “Skin Optics Summary “ at the website of Oregon medical laser institute.
· This gives us the approximate thickness of each skin layer as follows but it is merely for the sake of a descriptive convention (it says so in the article)[1]
· Thus we refer another article to find out a more in detailed skin optics model [2]
· In this article the thickness of skin layers is widely divergent from those assumed in the Skin Optics Summary (the thickness of the epidermis is 60 um in Skin Optics Summary but 0.027-0.15mm in the Study by the group in Univ.Waterloo)[2][1]
· The skin of a premature neonate is 40-60% less than the skin of an adult – [4]
· The Average thickness of the epidermis is 3 mm and that of the dermis is between 50 and 150 um. [3]
· From the above paper, it was also found that in dark skinned subjects, a higher absorption of melanin causes a reduction in reflectance values, although the overall reflectance pattern remained the same.[3]
· The average error was 0.12%, observed from the arm of a brown skinned subject. [3]
· Moreover, here we are considering the forehead of the neonate, so we first consider the thickness of the dermis and the epidermis in the forehead of an adult
· This is given by an epidermal thickness of mean value 0.253 and standard deviation 0.056[5]
· The dermal thickness is given by a mean value of 1.803 and a standard deviation of 0.252 [5]
· The thickness of adult skin is reported in the literature to vary according to subject and site, with the mean values reported between 0.9 and 1.3 nm [6].
· The twenty neonatal post mortem skin samples obtained for in vitro optical property measurements had a mean thickness of 888 .mu.m, and a standard deviation of 301 .mu.m (Section 2). The thickness of these skin samples was found to have only a weak correlation with gestational age of the neonate, as seen in FIG. 31. This relationship is: Skin thickness =22.5+25 (maturity)[6]
· Note: In the above equation, skin thickness is given in meters, and gestational maturity in weeks.
· In general the thickness of skin is modeled as being infinite
· This is justifiable as long as the wavlength of light is much greater than the thickness of the
· Finally the two models seemed too divergent to be integrated into a single one, thus two separate models were developed: the first being a multilayer model using the adult skin data and the second being a single layer simulation that approximates the epidermal and dermal scattering measurements
· Index of References
· 1-“Skin Optics Summary “, Oregon medical laser Center News, 1998,by Steven L.Jacques
· 2- “A study on Skin Optics” by Aravind Krishnaswamy and Gladimir V.G.Baranoski from the Natural Phenomena Simulation Group, School of Computer Science, University of Waterloo, Canada
· 3 - Electronic biopsy for skin cancer detection, by G.Florence Sudha and T.Ganesa Palnivelu of Pondicherry Engineering College in Current Science, Vol 87,No.5, 10 September 2004
· 4- Course on Neonatal Skin Care by the University of Chicago Children’s Hospital
· 5-Seventeen-point dermal ultrasound scoring system—a reliable measure of skin thickness in patients with systemic sclerosis ,T. L. Moore1, M. Lunt3, B. McManus2, M. E. Anderson1 and A. L. Herrick1,3
· 1University of Manchester Rheumatic Diseases Centre and 2Radiology Directorate, Hope Hospital, Salford M6 8HD and 3ARC Epidemiology Unit, University of Manchester M13 9PT, UK. ,Oxford Journal, Rheumatology 2003; 42: 1559-1563
6-www.freepatentsonline.com –Patent no. 5353790:Method and Apparatus for optical measurement of bilirubin in tissue