Mr. Rolf H. Bremmer Profile

Rolf H. Bremmer

PhD Student at Amsterdam UMC

SPIE Involvement:

Author

Publications (2)

SPIE Journal Paper | 28 August 2013 Open Access

Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering

Rolf Bremmer, Martin van Gemert, Dirk Faber, Ton van Leeuwen, Maurice Aalders

JBO, Vol. 18, Issue 08, 087007, (August 2013) https://doi.org/10.1117/12.10.1117/1.JBO.18.8.087007

KEYWORDS: Diffusion, Absorption, Diffuse reflectance spectroscopy, Scattering, Reflectivity, Reflectance spectroscopy, Blood, Tissues, Medicine, Forensic science

Read Abstract +

Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to the radiative transfer equation, implying that it is limited to tissues where the reduced scattering coefficient dominates over the absorption coefficient. Nevertheless, up to absorption coefficients of 20 mm −1 at reduced scattering coefficients of 1 and 11.5 mm −1 , we observed excellent agreement (r 2 =0.994 ) between reflectance measurements of phantoms and the diffuse reflectance equation proposed by Zonios et al. [Appl. Opt.38, 6628–6637 (1999)], derived as an approximation to one of the diffusion dipole equations of Farrell et al. [Med. Phys.19, 879–888 (1992)]. However, two parameters were fitted to all phantom experiments, including strongly absorbing samples, implying that the reflectance equation differs from diffusion theory. Yet, the exact diffusion dipole approximation at high reduced scattering and absorption also showed agreement with the phantom measurements. The mathematical structure of the diffuse reflectance relation used, derived by Zonios et al. [Appl. Opt.38, 6628–6637 (1999)], explains this observation. In conclusion, diffuse reflectance relations derived as an approximation to the diffusion dipole theory of Farrell et al. can analyze reflectance ratios accurately, even for much larger absorption than reduced scattering coefficients. This allows calibration of fiber-probe set-ups so that the object’s diffuse reflectance can be related to its absorption even when large. These findings will greatly expand the application of diffuse reflection spectroscopy. In medicine, it may allow the use of blue/green wavelengths and measurements on whole blood, and in forensic science, it may allow inclusion of objects such as blood stains and cloth at crime scenes.

DOWNLOAD PAPER

SPIE Journal Paper | 1 March 2010 Open Access

Optical phantoms of varying geometry based on thin building blocks with controlled optical properties

Daniel Martijn de Bruin, Rolf Bremmer, Vitali Kodach, Roy de Kinkelder, Jan van Marle, Ton van Leeuwen, Dirk Faber

JBO, Vol. 15, Issue 02, 025001, (March 2010) https://doi.org/10.1117/12.10.1117/1.3369003

KEYWORDS: Optical coherence tomography, Particles, Nanoparticles, Scattering, Absorption, Silicon, Signal attenuation, Gold, Optical phantoms, Confocal microscopy

Read Abstract +

DOWNLOAD PAPER

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years