Photoplethysmography (PPG) is a non-invasive technique to measure heart rate at a lower cost, and it has been recently widely used in smart wearable devices. However, as PPG is easily affected by noises under high-intensity movement, the measured heart rate in sports has low precision. To tackle the problem, this paper proposed a heart rate extraction algorithm based on self-adaptive heart rate separation model. The algorithm firstly preprocessed acceleration and PPG signals, from which cadence and heart rate history were extracted respectively. A self-adaptive model was made based on the connection between the extracted information and current heart rate, and to output possible domain of the heart rate accordingly. The algorithm proposed in this article removed the interference from strong noises by narrowing the domain of real heart rate. From experimental results on the PPG dataset used in 2015 IEEE Signal Processing Cup, the average absolute error on 12 training sets was 1.12 beat per minute (bpm) (Pearson correlation coefficient: 0.996; consistency error: −0.184 bpm). The average absolute error on 10 testing sets was 3.19 bpm (Pearson correlation coefficient: 0.990; consistency error: 1.327 bpm). From experimental results, the algorithm proposed in this paper can effectively extract heart rate information under noises and has the potential to be put in usage in smart wearable devices.
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.
ObjectiveTo understand the latest progress of enrichment technology of circulating tumor cells (CTCs), and summarize the principle, advantages and disadvantages of various enrichment technologies and their applications in primary liver cancer (PLC). MethodThe literature relevant to the enrichment methods of CTCs in the PLC was reviewed and summarized. ResultsThe clinical significances of CTCs in the early diagnosis and staging, hierarchical diagnosis and treatment, and efficacy monitoring of patients with PLC had been recognized. There were many separation and enrichment technologies for CTC, which were mainly based on the differences of physical and biochemical characteristics, as well as the combination of enrichment methods with various principles. Each enrichment method had corresponding advantages and disadvantages, and few enrichment methods for CTC was applied to PLC. ConclusionsAlthough many problems need to be solved in enrichment method of CTCs at present, it is believed that the existing problems will be solved one by one with continuous improvement of technology. And CTC detection is expected to apply in clinical, so as to provide more efficient diagnosis and treatment methods for patients with PLC.
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.
ObjectiveTo investigate the preparation and osteogenic properties of poly (L-lactic acid)(PLLA)/lecithin porous scaffolds with open pore structure.MethodsPLLA/lecithin porous scaffolds with different lecithin contents (0, 5%, 10%, 20%, 30%, 40%, 50%) were prepared by thermally induced phase separation (groups A, B, C, D, E, F, and G, respectively). Scanning electron microscopy (SEM) was used to observe the surface morphology of the scaffolds. Wide-angle X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to detect the crystallinity of the scaffolds. The water uptake ability of the scaffolds was measured. The cell growth and viability of bone marrow mesenchymal stem cells (BMSCs) of mouse on each scaffold was assessed by cell counting kit 8 (CCK-8) method. The osteogenic differentiation ability of BMSCs on each scaffold was evaluated by alkaline phosphatase (ALP) activity. Finally, a critical-size rat calvarial bone defect model was used to evaluate the osteogenesis of the scaffolds in vivo. Micro-CT was used to reconstruct the three-dimensional model of the defect area, and the bone volume and bone mineral density were quantitatively analyzed.ResultsSEM results showed that the lecithin could slightly reduce the pore size; when lecithin content was 50%, platelet-like structure could be observed on the scaffolds. Wide angle XRD and DSC showed that the crystallinity of scaffolds gradually decreased with the increase of lecithin content. The water uptake ability test showed that the hydrophilicity of scaffolds increased with the increase of lecithin content. CCK-8 assay showed that cell activity gradually increased with the increase of culture time. After 7 days of culture, the absorbance (A) value of groups C, D, E, and F were significantly higher than that of groups A, B, and G (P<0.05), but no significant difference was found among groups C, D, E, and F (P>0.05). After 14 days of osteogenic induction, with the increase of lecithin content, there was a significant difference in ALP activity of each group. The ALP activity in groups D, E, F, and G were significantly higher than that in groups A, B, and C (P<0.05).In vivo, the results of Micro-CT examination and bone volume and bone mineral density showed that the scaffolds with 30% lecithin had the best repairing effect.ConclusionPrepared by thermally induced phase separation, the cytocompatibility, osteogenic differentiation, and bone repair ability of the PLLA/lecithin porous scaffold is obviously better than that of pure PLLA scaffold. PLLA/lecithin porous scaffold with suitable lecithin content is a promising scaffold material for bone tissue engineering.
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.
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.
【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.
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.
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.