Local RegularizationMethod Applied to Estimating Oxy- gen Consumption During Muscle Activities

نویسندگان

  • Daniela Calvetti
  • Ranjan K. Dash
  • Erkki Somersalo
  • Marco E. Cabrera
چکیده

In this paper, we consider a one-dimensional inverse problem of estimating an input signal that a priori is known to be smooth functions with a few jump discontinuities. A popular method of regularizing the inverse problem with such prior information is to use a total variation (TV) penalty as a regularizing functional. In this article, we adopt a different approach, considering the problem from the Bayesian statistics viewpoint and using a hierarchical Gaussian smoothness prior. We demonstrate that the approach allows to construct a local regularization scheme that is computationally effective and reproduces well the jump discontinuities. The approach avoids the non-differentiability problems encountered in TV methods. Once discretized, the algorithm is completely data driven, the parameter selections requiring no user intervention. The method is applied to an inverse problem in metabolic modelling, where the objective is to estimate the mitochondrial oxygen consumption during muscle activities based on noisy observations of the time decay of the oxygen concentration on the muscle surface.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Modeling oxygenation in venous blood and skeletal muscle in response to exercise using near-infrared spectroscopy.

Noninvasive, continuous measurements in vivo are commonly used to make inferences about mechanisms controlling internal and external respiration during exercise. In particular, the dynamic response of muscle oxygenation (Sm(O(2))) measured by near-infrared spectroscopy (NIRS) is assumed to be correlated to that of venous oxygen saturation (Sv(O(2))) measured invasively. However, there are situa...

متن کامل

Recent developments in near-infrared spectroscopy (NIRS) for the assessment of local skeletal muscle microvascular function and capacity to utilise oxygen

PURPOSE OF REVIEW Continuous wave near infrared spectroscopy (CW NIRS) provides non-invasive technology to measure relative changes in oxy- and deoxy-haemoglobin in a dynamic environment. This allows determination of local skeletal muscle O2 saturation, muscle oxygen consumption ([Formula: see text]) and blood flow. This article provides a brief overview of the use of CW NIRS to measure exercis...

متن کامل

An efficient deconvolution algorithm for estimating oxygen consumption during muscle activities

The reconstruction of an unknown input function from noisy measurements in a biological system is an ill-posed inverse problem. Any computational algorithm for its solution must use some kind of regularization technique to neutralize the disastrous effects of amplified noise components on the computed solution. In this paper, following a hierarchical Bayesian statistical inversion approach, we ...

متن کامل

Hybrid diffuse optical techniques for continuous hemodynamic measurement in gastrocnemius during plantar flexion exercise.

Occlusion calibrations and gating techniques have been recently applied by our laboratory for continuous and absolute diffuse optical measurements of forearm muscle hemodynamics during handgrip exercises. The translation of these techniques from the forearm to the lower limb is the goal of this study as various diseases preferentially affect muscles in the lower extremity. This study adapted a ...

متن کامل

Central command contributes to increased blood flow in the noncontracting muscle at the start of one-legged dynamic exercise in humans.

Whether neurogenic vasodilatation contributes to exercise hyperemia is still controversial. Blood flow to noncontracting muscle, however, is chiefly regulated by a neural mechanism. Although vasodilatation in the nonexercising limb was shown at the onset of exercise, it was unclear whether central command or muscle mechanoreflex is responsible for the vasodilatation. To clarify this, using volu...

متن کامل

ذخیره 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 نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2005