Optical Skin-fat Thickness Measurement Using Miniaturized Chip LEDs: A Preliminary Human Study

Abstract

We tested the feasibility of measuring fat thickness using a miniaturized chip LED sensor module, testing 12 healthy female subjects. The module consisted of a single detector and four sources at four different source-detector distances (SD). A segmental curve-fitting procedure was applied, using an empirical algorithm obtained by Monte-Carlo simulation, and fat thicknesses were estimated. These thicknesses were compared to computed-tomography (CT) results; the correlation coefficient between CT and optical measurements was 0.932 for bicep sites. The mean percentage error between the two measurements was 13.12%. We conclude that fat thickness can be efficiently measured using the simple sensor module.

High-speed light source depth estimation using spatially-resolved diffuse imaging

“…Accurately characterising tissue properties then tends towards an ill-posed problem as the number of free parameters in an N-layer medium becomes N 3 1 when solving for μ a , s m ¢ and layer thickness (assuming a semi-infinite bottommost layer) [30]. However, the present scenario requires the estimation of only a single parameter and there remains the possibility that the presence of layered tissue does not heavily influence the ability to determine depth, as suggested by work simplifying the multilayer problem [18,[31][32][33]. Extending the geometry of the Monte Carlo forward model and performing simulations over the relevant parameter space will reveal the accuracy of this technique in multi-layer tissue, without necessarily increasing the complexity of the inverse model.…”

Evaluation of a multispectral diffuse optical spectroscopy device for assessment of cardiometabolic risk related alterations of body composition

“…These equations have been used for computation of the optical properties of biological tissues 6 , under the assumption that the tissue is homogeneous; however, for layered samples such as human tissue, these models cannot be readily applied, and instead, a more appropriate way would be the use of Monte-Carlo simulation 4 . That it-At short light source distances from photodetector (SD) light pass superficial layers (skin and adipose tissue), while at longer distances they penetrate into the deeper tissue layers reaching muscle tissue which significantly affect the diffuse reflectance intensity.…”

“…In general, our proposed method of subcutaneous fat measurement is based on simplified model containing one photodetector and many light sources situated at different distances and two underlying layers of media (adipose and muscle tissue) with different optical properties. In this model the subcutaneous fat layer serve as reflective medium (μ s = 10-15 cm -1 ; μ a = 0.05-0.8 cm -1 ) whereas muscle tissue contrary -absorb the reducing amount of back scattered light 1,3,4,5 . From the theory this process can be illustrated by a well-known equation -the Green's function solution of the diffusion equation which describes the light fluence rate 4 :…”

A Study of the Optical Properties of Cosmetics Measured by Polarized Light Goniophotometry

“…In addition to age, a person's genetics also affect skin light reflectance patterns and skin translucency [3,4]. Numerous studied have been performed to visualize the normal and diseased skin morphologies to measure the thickness using optical sensors [5,6]. Skin care products improve skin by treating the skin over time, and makeup products provide immediate physical changes in the light reflection properties by covering the spots and lines.…”