Effect of glucose on the optical properties of arterial blood using Mie theory simulations

The glucose concentration in arterial plasma has immediate effects on the optical properties of blood-bearing tissue due primarily to the alteration of refractive index mismatch between the scattering particles (red blood cells) and the medium (plasma). The influence of these effects on pulse oximetry is investigated using a numerical model based on Mie theory. The objective is to determine whether or not physiological fluctuations in blood glucose levels could sufficiently vary the optical properties to shift the calibration curve of a commercial pulse oximeter significantly

Analysis of skin recovery from mechanical indentation using diffuse lighting and digital imaging

Skin behaves as a viscoelastic material, having mechanical properties composed of elastic and fluid components. Upon indentation, the fibres are stretched and fluid displaced from the compressed region. The rate of recovery from this imprint is therefore dependent on the hydration and elasticity of the skin. A reliable measurement could be applied to the assessment of clinical conditions such as oedema, rare genetic disorders such as cutis laxa and the evaluation of the 'effective age' of skin in vivo. This paper describes a new approach to the non-invasive indentation technique and a novel method of analysis. A method is proposed that tracks the skin's recovery optically from an initial strain made using a mechanical indentor, diffuse side-lighting and a CCD video-capture device. Using the blue colour plane of the image it is possible to examine the surface topography only, and track the decay of the imprint over time. Two algorithms are discussed for the extraction of information on the skin's displacement and are analysed in terms of reliability and reproducibility

Visualization 2: Intraoperative measurement of bowel oxygen saturation using a multispectral imaging laparoscope

Variation of small bowel StO2 over time during clamping and unclamping of the mesenteric arcade. Originally published in Biomedical Optics Express on 01 October 2015 (boe-6-10-4179

Visualization 3: Intraoperative measurement of bowel oxygen saturation using a multispectral imaging laparoscope

Variation of small bowel StO2 over time during euthanasia of porcine subject. Originally published in Biomedical Optics Express on 01 October 2015 (boe-6-10-4179

Media 2: Multispectral image alignment using a three channel endoscope in vivo during minimally invasive surgery

Originally published in Biomedical Optics Express on 01 October 2012 (boe-3-10-2567

Media 1: Multispectral image alignment using a three channel endoscope in vivo during minimally invasive surgery

Originally published in Biomedical Optics Express on 01 October 2012 (boe-3-10-2567

Media 3: Multispectral image alignment using a three channel endoscope in vivo during minimally invasive surgery

Originally published in Biomedical Optics Express on 01 October 2012 (boe-3-10-2567