Direct calculation of the moments of the distribution of photon time of flight in tissue with a finite-element method.
نویسندگان
چکیده
Modeling of the full temporal behavior of photons propagating in diffusive materials is computationally costly. Rather than deriving intensity as a function of time to fine sampling, we may consider methods that derive a transform of this function. To derive the Fourier transform involves calculation in the (complex) frequency domain and relates to intensity-modulated experiments. We consider instead the Mellin transform and show that this relates to the moments of the original temporal distribution. A derivation of the Mellin transform given the Fourier transform that permits closed-form derivations of the temporal moments for various simple geometries is presented. For general geometries a finite-element method is presented, and it is demonstrated that the computational cost to produce the nth moment is the same as producing the first n temporal samples of the original function.
منابع مشابه
Modeling Time Resolved Light Propagation Inside a Realistic Human Head Model
Background: Near infrared spectroscopy imaging is one of the new techniques used for investigating structural and functionality of different body tissues. This is done by injecting light into the medium and measuring the photon intensity at the surface of the tissue.Method: In this paper the different medical applications, various imaging and simulation techniques of NIRS imaging is described. ...
متن کاملDirect calculation with a finite-element method of the Laplace transform of the distribution of photon time of flight in tissue.
Reconstruction methods for optical tomographic imaging require the development of models of light transport in highly scattering materials. While the simulation of the full temporal response function arising from a short source light pulse is computationally expensive, there are methods to evaluate efficiently certain transforms of the temporal profile. We previously presented methods to obtain...
متن کاملQuantitative Comparison of Analytical solution and Finite Element Method for investigation of Near-Infrared Light Propagation in Brain Tissue Model
Introduction: Functional Near-Infrared Spectroscopy (fNIRS) is an imaging method in which light source and detector are installed on the head; consequently, re-emission of light from human skin contains information about cerebral hemodynamic alteration. The spatial probability distribution profile of photons penetrating tissue at a source spot, scattering into the tissue, and being released at ...
متن کاملModeling of Tactile Detection of an Artery in a Soft Tissue by Finite Element Analysis
Nowadays, one of the main problems encountered in minimally invasive surgery and telesurgery is the detection of arteries in tissue. In this study, for the first time, tactile detection of an artery in tissue and distinguishing it from the tumor has been modeled by finite element method. In this modeling, three 2D models of tissue have been created: tissue, tissue including a tumor, and tissue ...
متن کاملSolution of Wave Equations Near Seawalls by Finite Element Method
A 2D finite element model for the solution of wave equations is developed. The fluid is considered as incompressible and irrotational. This is a difficult mathematical problem to solve numerically as well as analytically because the condition of the dynamic boundary (Bernoulli’s equation) on the free surface is not fixed and varies with time. The finite element technique is applied to solve non...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Applied optics
دوره 34 15 شماره
صفحات -
تاریخ انتشار 1995