MiRNA and Alzheimer′s disease / 中华检验医学杂志

Alzheimer′s disease (AD) is a degenerative neurodegenerative disease of the central nervous system. The disease is concealed. Patients often experienced several years or even more than ten years of course evolution from the beginning of pathological changes to clinical symptoms. Once entering the stage of dementia, there is no ideal drug to reverse the disease. In order to improve the efficiency of early diagnosis, the research on early biomarkers of the disease has become a hot topic in recent years. In addition to the Aβ and tau, microRNAs have been discovered as potential biomarkers of AD.

An endpoint-detection algorithm of surface electromyography insensitive to electrocardiogram interference / 生物医学工程学杂志

Surface electromyography (sEMG) has been widely used in the study of clinical medicine, rehabilitation medicine, sports, etc., and its endpoints should be detected accurately before analyzing. However, endpoint detection is vulnerable to electrocardiogram (ECG) interference when the sEMG recorders are placed near the heart. In this paper, an endpoint-detection algorithm which is insensitive to ECG interference is proposed. In the algorithm, endpoints of sEMG are detected based on the short-time energy and short-time zero-crossing rates of sEMG. The thresholds of short-time energy and short-time zero-crossing rate are set according to the statistical difference of short-time zero-crossing rate between sEMG and ECG, and the statistical difference of short-time energy between sEMG and the background noise. Experiment results on the sEMG of rectus abdominis muscle demonstrate that the algorithm detects the endpoints of the sEMG with a high accuracy rate of 95.6%.

Detection of lung mini-nodules using multi-feature tracking / 生物医学工程学杂志

How to accurately identify mini-nodules in a large amount of high resolution computed tomography (HRCT) images is always a significant and difficult issue in lung nodule computer-aided detection (CAD). This paper describes a new mini-nodules detection method which is based on a multi-feature tracking algorithm. Our detection method began after running the Da-Jing algorithm and morphological operation to extract the lung region of every HRCT image in a sequence. Once the lung had been extracted, a hybrid algorithm, combining gray threshold and improved template matching, was used to obtain the regions of interest (ROD). Next, several characteristics of each ROI were calculated to identify the final results by using multi-feature tracking throughout the whole HRCT image sequence. The results showed that the proposed method would be of high accuracy with a low occurrence of false positives.

On evaluating the robot-based experimental system for biomechanical experiment of human knee / 生物医学工程学杂志

This is a report on how we use the hybrid force-displacement control method to load the human knee and analyze the effect and value of our robot experimental system through the biomechanical experiments of total meniscal resection of human knee. The whole robot control system can load continuously on the specimens, thus overcoming the shortcomings of the traditional loading methods which can only load discretely. In the meantime, by using the robot-based testing system, the force (torque) of the specimens and the spatial position under the force can be measured in real-time, which overcomes the shortcomings caused by the separation of force (torque) measurement from displacement measurement and so greatly improves the measurement accuracy.

Biomechanic research on short-segment posterior pedicle screw fixation / 中华创伤杂志

Objective To compare the stability effect of the fixation segment using the new test system based robotics to simulate the complex human movement at natural state about the three-level fixa-tion by using four, five or six pedicle screws in treatment of thoracolumbar burst fractures. Methods Six human cadaveric spines were dissected from T_(11)-L_3. The inferior half part of L_1 vertebral bodies and L_1-L_2 dises were resected to mimie an unstable L_1 burst fracture with loss of anterior column support. Specimens were tested in accordance with the following order:intact, 4,5 and 6 pedicle screws fixation at the three-level fixation. The range of motion (ROM) of the fixation segment (T_(11)-L_3) was measured with the six-freedom degree robotics system controlled by mixed force and displacement during flexion, exten-sion, lateral bending and axial torsion, when the stiffness was calculated. One-way statistieal analysis was used for analyzing the collected data. Results With increased number of screws, the ROM of the fixa-tion segment (T_(11)-L_3) was gradually decreased and the stiffness gradually increased. The ROM under ax-ial rotation of six and five screws group became smaller than four screws group (P < 0.05). The stiffness under axial rotation of six screws group was higher than four screws group (P < 0.05). There was no sta-tistical difference between five screws group and four screws group in regard of the stiffness in axial rota-tion (P > 0.05). There were no significant differences in ROM and stiffness under six different loading directions between six screws group and five screws group (P > 0.05). No statistical difference was observed for three fixation modes in aspects of ROMs and stiffness under flexion-extension or lateral ben-ding (P > 0.05). Conclusions Three-level fixation of burst fractures with five or six screws offers im-proved biomechanical stability compared with traditional four screws fixation. But the difference is insig-nificant between six and five screws fixations.

CAD for identifying malignant lung nodules in early diagnosis: a survey / 生物医学工程学杂志

It is of paramount importance for the diagnosis and therapy of lung cancer, even for the increasing of 5-year survival rate in that the early dignosis of malignant pulmonary nodules are made by intelligent identification successfully. As it stands, in intelligent identification of pulmonary nodules, computer-aided detection/diagnosis (CAD) plays the most important role. The key points of intelligent identification of pulmonary nodules are (1) Detecting pulmonary nodules based on the characterization of nodule appearance; (2) Measuring accurately the nodule size; (3) Computing accurately the growth rate. This article presents a review on the basic technologies and methods of CAD for identifying malignant pulmonary nodules in the course of making early diagnosis, including lung segmentation, registration of volume data, identification of benign/malignant pulmonary nodule, and so on.

Research of joint-robotics-based design of biomechanics testing device on human spine / 生物医学工程学杂志

This paper introduces the hardware and software of a biomechanical robot-based testing device. The bottom control orders, posture and torque data transmission, and the control algorithms are integrated in a unified visual control platform by Visual C+ +, with easy control and management. By using hybrid force-displacement control method to load the human spine, we can test the organizational structure and the force state of the FSU (Functional spinal unit) well, which overcomes the shortcomings due to the separation of the force and displacement measurement, thus greatly improves the measurement accuracy. Also it is esay to identify the spinal degeneration and the load-bearing impact on the organizational structure of the FSU after various types of surgery.

A preliminary research on multi-source medical image fusion / 生物医学工程学杂志

Multi-modal medical image fusion has important value in clinical diagnosis and treatment. In this paper, the multi-resolution analysis of Daubechies 9/7 Biorthogonal Wavelet Transform is introduced for anatomical and functional image fusion, then a new fusion algorithm with the combination of local standard deviation and energy as texture measurement is presented. At last, a set of quantitative evaluation criteria is given. Experiments show that both anatomical and metabolism information can be obtained effectively, and both the edge and texture features can be reserved successfully. The presented algorithm is more effective than the traditional algorithms.

Application of GVF snake model in segmentation of whole body bone SPECT image / 生物医学工程学杂志

Limited by the imaging principle of whole body bone SPECT image, the gray value of bladder area is quite high, which affects the image's brightness, contrast and readability. In the meantime, the similarity between bladder area and focus makes it difficult for some images to be segmented automatically. In this paper, an improved Snake model, GVF Snake, is adopted to automatically segment bladder area, preparing for further processing of whole body bone SPECT images.

Fast multi-resolution volume rendering method of large medical data sets / 生物医学工程学杂志

A Fast Multi-resolution Volume Rendering Method (FMVRM) based on wavelet and Shear-Warp is herein proposed. In this method, the medical volume data is compressed using wavelet transformation first. Then based on the set resolution, the medical volume data is decompressed guided by Opacity transfer function (OTF). Finally, the 3D medical image is reconstructed on the basis of Shear-Warp using Block-based run length encoded (BRLE) data structure, in which, the aliasing artifacts resulting from under-sampling in Shear-Warp is avoided by the pre-integrated volume rendering technology. Experiments demonstrate the good performance of the proposed method.

A hybrid volume rendering method using general hardware / 生物医学工程学杂志

In order to improve the effect and efficiency of the reconstructed image after hybrid volume rendering of different kinds of volume data from medical sequential slices or polygonal models, we propose a hybrid volume rendering method based on Shear-Warp with economical hardware. First, the hybrid volume data are pre-processed by Z-Buffer method and RLE (Run-Length Encoded) data structure. Then, during the process of compositing intermediate image, a resampling method based on the dual-interpolation and the intermediate slice interpolation methods is used to improve the efficiency and the effect. Finally, the reconstructed image is rendered by the texture-mapping technology of OpenGL. Experiments demonstrate the good performance of the proposed method.

Multimodal medical image registration using cubic spline interpolation method / 生物医学工程学杂志

Based on the characteristic of the PET-CT multimodal image series, a novel image registration and fusion method is proposed, in which the cubic spline interpolation method is applied to realize the interpolation of PET-CT image series, then registration is carried out by using mutual information algorithm and finally the improved principal component analysis method is used for the fusion of PET-CT multimodal images to enhance the visual effect of PET image, thus satisfied registration and fusion results are obtained. The cubic spline interpolation method is used for reconstruction to restore the missed information between image slices, which can compensate for the shortage of previous registration methods, improve the accuracy of the registration, and make the fused multimodal images more similar to the real image. Finally, the cubic spline interpolation method has been successfully applied in developing 3D-CRT (3D Conformal Radiation Therapy) system.

Segmentation of whole body bone SPECT image based on BP neural network / 生物医学工程学杂志

In this paper, BP neural network is used to segment whole body bone SPECT image so that the lesion area can be recognized automatically. For the uncertain characteristics of SPECT images, it is hard to achieve good segmentation result if only the BP neural network is employed. Therefore, the segmentation process is divided into three steps: first, the optimal gray threshold segmentation method is employed for preprocessing, then BP neural network is used to roughly identify the lesions, and finally template match method and symmetry-removing program are adopted to delete the wrongly recognized areas.