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ABSTRACT: At present, navigation path deviation caused by brain shift is the main factor that affects the accuracy of neurosurgical navigation. A new method of near infrared spectroscopy (NIRS) based neurosurgical navigation is presented in the paper. The correlation between NIRS optical parameters and medical image is used and the gray information of navigation path is regarded as the priori knowledge, the curvatures of sample-points are calculated by Hermite interpolation and the Mean Hausdorff distance as measurement criterion is used to match feature segments, then the real-time correction model is established. The algorithm of the given model is simple and can realize the best match within the error, and it provides an effective method for real-time navigation path correction.
Biomedical Engineering and Informatics (BMEI), 2010 3rd International Conference on; 11/2010
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ABSTRACT: At present, navigation path deviation caused by brain shift is the main factor that affects the accuracy of neurosurgical navigation. A new method of near infrared spectroscopy (NIRS) based neurosurgical navigation is presented in the paper. The correlation between NIRS optical parameters and medical image is used and the gray information of navigation path is regarded as the priori knowledge, sample-points curvatures are calculated by Hermite interpolation and the Mean Hausdorff distance as measurement criterion is used to match feature segments, then the real-time correction model is established. The algorithm of the given model is simple and can realize the best match within the error, it provides an effective method for real-time navigation path correction.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 08/2010; 27(4):887-92.
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ABSTRACT: Medical image fusion is of very important value for application in medical image analysis and diagnosis. In this paper, the conventional method of wavelet fusion is improved,so a new algorithm of medical image fusion is presented and the high frequency and low frequency coefficients are studied respectively. When high frequency coefficients are chosen, the regional edge intensities of each sub-image are calculated to realize adaptive fusion. The choice of low frequency coefficient is based on the edges of images, so that the fused image preserves all useful information and appears more distinctly. We apply the conventional and the improved fusion algorithms based on wavelet transform to fuse two images of human body and also evaluate the fusion results through a quality evaluation method. Experimental results show that this algorithm can effectively retain the details of information on original images and enhance their edge and texture features. This new algorithm is better than the conventional fusion algorithm based on wavelet transform.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 08/2009; 26(4):711-5.
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ABSTRACT: The superior imaging manner of intravascular ultrasound becomes more and more widely used in the diagnosis of coronary heart disease and intervention therapy. However, as the frequency of ultrasound increases, strong speckled echo signal from blood may significantly decrease the contrast of lumen and arterial wall structure, which may make it difficult for doctor to diferentiate and measure geometrical parameters and physical parameters of lumen and plaque. In this paper a novel noise reduction method is introduced, which utilizes the temporal and spatial information of IUVS, that is blood echo speckles have higher temporal and spatial variation than the arterial wall. When signals transferred into the frequency field, tissue and blood present different frequency spectrum, then a radio of high frequency energy and low frequency energy is introduced to determine speckles or tissue. Result showed that the method can remarkably remove the speckle noise, increase the contrast and help doctor differentiate the arterial wall from the around tissues.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 01/2007; 23(6):1213-7.
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ABSTRACT: Ray casting algorithm can obtain better quality images in volume rendering, however, it presents some problems such as powerful computing capacity and slow rendering velocity. Therefore, a new fast algorithm of ray casting volume rendering is proposed in this paper. This algorithm reduces matrix computation by the matrix transformation characteristics of re-sampling points in two coordinate system, so re-sampled computational process is accelerated. By extending the Bresenham algorithm to three dimension and utilizing boundary box technique, this algorithm avoids the sampling in empty voxel and greatly improves the efficiency of ray casting. The experiment results show that the improved acceleration algorithm can produce the required quality images, at the same time reduces the total operations remarkably, and speeds up the volume rendering.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 11/2006; 23(5):1003-7.
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ABSTRACT: In the examination of 3D DCE-MRA, it is the key of success or failure to measure and compute the delaying scan time accurately. Now, the timing technique used widely in clinic is test injection bolus, which is limited by inadequate perfectibility, limited spatial resolution and technique complexity. In this article is presented a technique in which contrast arrival is detected in the targeted vasculature in real time using MR fluoroscopy. Upon detection the operator triggers a 3D MR angiographic acquisition which uses an elliptical centric view order. It is shown that the view order intrinsically provides a high degree of venous suppression, a high degree of immunity to motion effects and a high degree of spatial resolution. The reliability of fluoroscopic triggering in bolus detection is shown to be over 95%. The technique provides high quality contrast-enhanced MR angiograms for many vascular regions.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 01/2006; 22(6):1134-9.
