Determining fractal dimension of umbilical artery Doppler signals using Hurst exponent

Assessment of cerebral hemodynamics during neurosurgical procedures using laser speckle image analysis

Aneurysmal subarachnoid hemorrhage (aSAH) is a severe medical condition associated with a significant cause of mortality throughout the world. Cisterna magna injection model is accepted widely to mimic clinical aSAH and is performed on small animal models to study aSAH during neurosurgery. Coherent light scattered from the surface of the rat brain is used to infer information about the variations in blood flow during this condition. We obtained speckle images from the exposed cortex during the entire experiment using an external tissue imaging system. Contrast and fractal analyses are carried out for the recorded speckle pattern time series. Correlation analysis based on Hurst exponent for these images is found to be a more sensitive tool in studying aSAH as compared to routinely used laser speckle contrast analysis for assessing the changes in blood flow velocity. Additionally, our studies provide improved blood flow detection sensitivity with image Hurst exponent in combination with computed fractal dimension, during an event of aSAH.

Non-invasive diagnosis of stress urinary incontinence sub types using wavelet analysis, shannon entropy and principal component analysis

Urinary incontinence is a common female disorder. Although generally not a serious condition, it negatively affects the lifestyle and daily activity of subjects. Stress urinary incontinence (SUI) is the most versatile of several incontinence types and is distinguished by physical degeneration of the continence-providing mechanism. Some surgical treatment methods exist, but the success of the surgery mainly depends upon a correct diagnosis. Diagnosis has two major steps: subjects who are suffering from true SUI must be identified, and the SUI sub-type must be determined, because each sub-type is treated with a different surgery. The first step is straightforward and uses standard identification methods. The second step, however, requires invasive, uncomfortable urodynamic studies that are difficult to apply. Many subjects try to cope with the disorder rather than seek treatment from health care providers, in part because of the invasive diagnostic methods. In this study, a diagnostic method with a success rate comparable to that of urodynamic studies is presented. This new method has some advantages over the current one. First, it is noninvasive; data are collected using Doppler ultrasound recording. Second, it requires no special tools and is easy to apply, relatively inexpensive, faster and more hygienic.