【Abstract】 Objective To summary the effects of staged pelvic closure using external fixator combined withreconstruction plate for old Tile B1 pelvic fracture. Methods From August 2000 to August 2006, 14 patients (9 males and 5 females, age ranging from 21 to 65 years with old Tile B1 pelvic fracture with pubic symphysis separation were treated. The injuries were caused by the traffic accident in 10 patients, high crash in 3, and crush in 1. The duration ranged from 4 weeks to 3 months. The 14 patients were compl icated with other injuries in some degrees. The X-ray and CT showed pubic symphysis separation. In 13 patients, pubic symphysis separation distance was more than 2.5 cm, who also had fracture or dislocation in the posterior structure of pelvis. The X-ray films showed the mean pubic symphysis separation distance was (6.67 ± 2.11) cm preoperatively. The 14 patients underwent pelvic external fixation at first and staged pelvic closure gradually for the pubic symphysis separation. After 2 to 3 weeks, when the pubic symphysis separation distance was less than 1 cm, the patients underwent open reduction and internal fixation with reconstruction plate. Pubic symphysis separation distance was measuredin the preoperative and postoperative pelvic anterioposterior X-ray films. The condition of the posterior structure of pelvis was observed in CT films. The functions of patients were assessed according to Majeed grading system. Results All incisions healed by first intention. The 14 patients were followed up for 6 months to 2 years (15 months on average). The X-ray films showed the mean pubic symphysis separation distance of post-operation was (0.85 ± 0.23) cm, showing statistically significant difference when compared with that of pre-operation (P lt; 0.05). The CT films showed fracture and dislocation of the posterior structure of pelvis had bony heal ing after 6 to 12 months. According to the Majeed grading system, the results were excellent in 5 cases, good in 4 cases, fair in 4 cases and poor in 1 case; the excellent and good rate was 64.29%. Conclusion Staged pelvic closure using external fixation combined with reconstruction plate for old pelvic fracture with pubic symphysis separation can reduce the pubic symphysis separation distance significantly. Satisfactory effects can be expected in treating the patients with TileB1 fracture.
Objective To investigate the culture method forepidermal stem cells in vitro. Methods The epidermis was separated from the dermis, and shaken for 10 min in 0.05% trypsin at 37℃ to dissociate into single cells. Epidermal stem cells were selected by rapid attachment to collagen Ⅳ for 10-15 min and cultured on collagen Ⅳ or 3T3 feeder layer. All the cells were grown in DMEM without calcium, supplemented with 10% chelexed fetalbovine serum, 10 μg/L epidermal growth factor, 0.05 mmol/L CaCl2 and 0.8 mg/L hydrocortisone. Cultures were observed for colony formation under a phase constrast microscope. The phenotypes of epidermal stem cells were detected by flow cytometry and immunocytochemistry staining. Results The cells selectedby rapid adherence to collagen Ⅳ formed large colonies at 7～8 days, expressedK19 antigen. The percentages of cells at the G0 and G1 phases of the cell cycle and the percentage of α6briCD71dim cells in the experimental groups were higher than those in the control group. It indiciated that there was a significant difference between the experimental groups and the control groups(P＜0.05). ConclusionThe humanepidermal stem cells can be selected by rapid attachment to collagen Ⅳ, and they can be expanded in culture if the appropriate conditions are maintained.
In the present investigation, we studied four methods of blind source separation/independent component analysis (BSS/ICA), AMUSE, SOBI, JADE, and FastICA. We did the feature extraction of electroencephalogram (EEG) signals of brain computer interface (BCI) for classifying spontaneous mental activities, which contained four mental tasks including imagination of left hand, right hand, foot and tongue movement. Different methods of extract physiological components were studied and achieved good performance. Then, three combined methods of SOBI and FastICA for extraction of EEG features of motor imagery were proposed. The results showed that combining of SOBI and ICA could not only reduce various artifacts and noise but also localize useful source and improve accuracy of BCI. It would improve further study of physiological mechanisms of motor imagery.
To separate the overlapped protein spots in two-dimensional gel electrophoresis (2-DE) images, we proposed an auto-separating algorithm based on valley characteristics. Firstly, the marker-controlled watershed algorithm was used to detect the initial outlines of the object regions. Secondly, medial axis transform and hierarchical branch pruning method were applied to the main skeletons of the object regions, and each main skeleton was fitted into line segments to describe the overlap directions. Then, the 3-dimensional model of the object region was scanned on the normal planes of the line segments to find the valley locations. And finally, a validation model was adopted to construct separation lines. The experiments on 2 real scanned 2-DE images showed that the true overlap separate (TOSs) were 78.95% and 85.71%, respectively. The results indicated that the proposed algorithm was better than the existing algorithms and could be used in engineering practice.
A new method based on convolution kernel compensation (CKC) for decomposing multi-channel surface electromyogram (sEMG)signals is proposed in this paper. Unsupervised learning and clustering function of self-organizing map (SOM) neural network are employed in this method. An initial innervations pulse train (IPT) is firstly estimated, some time instants corresponding to the highest peaks from the initial IPT are clustered by SOM neural network. Then the final IPT can be obtained from the observations corresponding to these time instants. In this paper, the proposed method was tested on the simulated signal, the influence of signal to noise ratio (SNR), the number of groups clustered by SOM and the number of highest peaks selected from the initial pulse train on the number of reconstructed sources and the pulse accuracy were studied, and the results show that the proposed approach is effective in decomposing multi-channel sEMG signals.
The impulsive electroencephalograph (EEG) noises in evoked potential (EP) signals is very strong, usually with a heavy tail and infinite variance characteristics like the acceleration noise impact, hypoxia and etc., as shown in other special tests. The noises can be described by α stable distribution model. In this paper, Wigner-Ville distribution (WVD) and pseudo Wigner-Ville distribution (PWVD) time-frequency distribution based on the fractional lower order moment are presented to be improved. We got fractional lower order WVD (FLO-WVD) and fractional lower order PWVD (FLO-PWVD) time-frequency distribution which could be suitable for α stable distribution process. We also proposed the fractional lower order spatial time-frequency distribution matrix (FLO-STFM) concept. Therefore, combining with time-frequency underdetermined blind source separation (TF-UBSS), we proposed a new fractional lower order spatial time-frequency underdetermined blind source separation (FLO-TF-UBSS) which can work in α stable distribution environment. We used the FLO-TF-UBSS algorithm to extract EPs. Simulations showed that the proposed method could effectively extract EPs in EEG noises, and the separated EPs and EEG signals based on FLO-TF-UBSS were almost the same as the original signal, but blind separation based on TF-UBSS had certain deviation. The correlation coefficient of the FLO-TF-UBSS algorithm was higher than the TF-UBSS algorithm when generalized signal-to-noise ratio (GSNR) changed from 10 dB to 30 dB and α varied from 1.06 to 1.94, and was approximately equal to 1. Hence, the proposed FLO-TF-UBSS method might be better than the TF-UBSS algorithm based on second order for extracting EP signal under an EEG noise environment.
One of the key problems of brain-computer interfaces (BCI) is low signal-to-noise ratio (SNR) of electroencephalogram (EEG) signals. It affects recognition performance. To remove the artifact and noise, block under-determined blind source separation method based on the small number of channels is proposed in this paper. The non-stationary EEG signals are turned into block stationary signals by piecewise. The mixing matrix is estimated by the second-order under-determined blind mixing matrix identification. Then, the beamformer based on minimum mean square error separates the original sources of signals. Eventually, the reconstructed EEG for mixed signals removes the unwanted components of source signals to achieve suppressing artifact. The experiment results on the real motor imagery BCI indicated that the block under-determined blind source separation method could reconstruct signals and remove artifact effectively. The accuracy of motor imagery task of BCI has been greatly improved.
ObjectiveTo investigate the feasibil ity and short-term effectiveness of percutaneous endoscopic spine surgery for treatment of lumbar disc herniation with posterior ring apophysis separation. MethodsBetween July 2008 and January 2013, 57 patients with lumbar disc herniation and posterior ring apophysis separation were treated. There were 39 males and 18 females, aged from 13 to 46 years (mean, 26.7 years). Of 57 cases, 29 had a clear trauma history. All patients had single segmental unilateral lumbar disc herniation, and the location was at L4, 5 in 22 cases and at L5, S1 in 35 cases; there were 25 cases of lateral bone fragments and 32 cases of central cortical and cancellous fragments. While fracture located at posterior inferior edge of the vertebrae at L4 level in 9 cases and at L5 level in 8 cases, at posterior superior edge at L5 level in 13 cases and in S1 level in 27 cases. Percutaneous endoscopic surgeries were performed via interlaminar or transforaminal approach from unilaterally symptomatic side for discectomy of lumbar disc herniation and partial or complete resection of free bone fragments. ResultsAccurate positioning was obtained in all patients during operation, and no complication of nerve root injury, hematoma formation, or dural tear occurred. The operation time was 20-85 minutes; the intraoperative fluoroscopy times were 2-15 times, and the blood loss was 3-10 mL. Postoperative radiographic examination showed that bone fragment was not removed in 16 cases, was partly removed in 32 cases, and was completely removed in 9 cases. Disc was completely removed. All patients were followed up 10-64 months (median, 16 months). According to modified Macnab criteria for the evaluation of effectiveness, the results were excellent in 48 cases, good in 6 cases, and fair in 3 cases, and the excellent and good rate was 94.7%. ConclusionPercutaneous endoscopic spine surgery through unilaterally symptomatic approach has advantages of small tissue damage and lumbar structure damage, less bleeding, and shorter recovery time. It has a good short-term effectiveness, but long-term effectiveness need further follow-up.
Blind source separation technique based on independent component analysis (ICA) can separate blood volume pulse (BVP) from the facial video and then realize the telemetry of heart rate, blood oxygen saturation, respiratory rate and other vital signs parameters. However, the superiority of ICA in BVP extraction has not been demonstrated in the existing researches. Some researchers suggested using traditional G-channel method for BVP extraction (G-BVP) instead of ICA method (ICA-BVP). This study investigated the applicability of ICA-BVP comparatively. To solve the inherent permutation problem of ICA, a spectral kurtosis-based method was proposed for BVP identification. The experimental results based on the facial video datasets from 9 subjects shows that ICA-BVP method has apparent advantages in motion artifacts attenuation and ambient light changes elimination. The kurtosis-based method achieved a good performance in BVP identification and dynamic heart rate (HR) estimation. In practical application, the proposed ICA-BVP method could present a better stability and accuracy in vital signs parameters extraction.
Objective To investigate the clinical efficacy between suture button plate and cortical screw in the treatment of distal tibiofibular syndesmosis seperation. Methods The clinical data and follow-up data 1 week and 2, 4, 6 weeks and 3, 6, 12 months after operation of patients with distal tibiofibular syndesmosis seperation combined with or without ankle fracture who were admitted to hospital from March 2011 to May 2014 were retrospectively collected. According to the fixation ways of distal tibiofibular syndesmosis, the patients were divided into the suture button plate group and the cortical screw group. The operation time, amount of blood loss, combined ankle fracture healing time, American Orthopaedic Foot and Ankle Society (AOFAS) scores at the last follow-up and complications were compared between the two groups. Results A total of 52 patients were enrolled, including 28 cases of suture button plate group and 24 cases of cortical screw group. There were no significant difference in operation time or amount of blood loss between the two groups (P>0.05). All patients were followed up for 12–30 months averaged 14.5 months. All incisions healed by the first intention. The combined ankle fracture healing time in the suture button plate group was (11.2±2.0) weeks, while that was (11.0±2.1) weeks in the cortical screw group, with no significant difference between the two groups (P>0.05). In the suture button plate group, there was no loosening or rupture of internal fixation, while distal tibiofibular syndesmosis seperation was found again in one case 3 weeks after operation, and cured by reoperation at last. In the cortical screw group, rupture of screws was found in 2 cases, which occurred 9 and 11 weeks after operation respectively, and the broken screws were taken out when the fractures were healed and the internal fixation was removed; distal fibiofibular syndesmosis seperation was found again in one case 6 weeks after operation, and no treatment was given due to old age and low demand. At the last follow-up, the AOFAS score in the suture button plate group was 84.6±10.2, while the score in the cortical screw group was 83.7±12.5, with no significant difference between the two groups (P>0.05). Conclusions Suture button plate and cortical screw can effectively treat distal fibiofibular syndesmosis separation. The risk of suture button plate loosening or rupture is poor. Suture button plate fixation can meet the need of early functional exercises, and avoid the routine removal by reoperation.