VLSI Implementation and Analysis of Kidney Stone Detection by Level Set Segmentation and ANN Classification

The abnormalities of the kidney can be identified by ultrasound imaging. The kidney may have structural abnormalities like kidney swelling, change in its position and appearance. Kidney abnormality may also arise due to the formation of stones, cysts, cancerous cells, congenital anomalies, blockage of urine etc. For surgical operations it is very important to identify the exact and accurate location of stone in the kidney. The ultrasound images are of low contrast and contain speckle noise. This makes the detection of kidney abnormalities rather challenging task. Thus preprocessing of ultrasound images is carried out to remove speckle noise. In preprocessing, first image restoration is done to reduce speckle noise then it is applied to Gabor filter for smoothening. Next the resultant image is enhanced using histogram equalization. Level set segmentation is applied two times, first to segment kidney portion and its output is the input to second to segment stone portion, since it yields better results. In level set segmentation two terms are used in our work. First is using a momentum term and second is based on resilient propagation (Rprop). Extracted region of the kidney stone after segmentation is applied to Symlets, Biorthogonal (bio3.7, bio3.9 & bio4.4) and Daubechies lifting scheme wavelet subbands to extract energy levels. These energy level gives an indication about presence of stone, which significantly vary from that of normal energy level. These energy levels are trained by Multilayer Perceptron (MLP) and Back Propagation (BP) ANN to identify the type of stone with an accuracy of 98.8% and real time implementation is done using Verilog on Vertex-2Pro FPGA.