Characteristics in pulse wave signals (PWSs) include the information of physiology and pathology of human cardiovascular system. Therefore, identification of characteristic points in PWSs plays a significant role in analyzing human cardiovascular system. Particularly, the characteristic points show personal dependent features and are easy to be affected. Acquiring a signal with high signal-to-noise ratio (SNR) and integrity is fundamentally important to precisely identify the characteristic points. Based on the mathematical morphology theory, we design a combined filter, which can effectively suppress the baseline drift and remove the high-frequency noise simultaneously, to preprocess the PWSs. Furthermore, the characteristic points of the preprocessed signal are extracted according to its position relations with the zero-crossing points of wavelet coefficients of the signal. In addition, the differential method is adopted to calibrate the position offset of characteristic points caused by the wavelet transform. We investigated four typical PWSs reconstructed by three Gaussian functions with tunable parameters. The numerical results suggested that the proposed method could identify the characteristic points of PWSs accurately.
In order to realize sleep staging automatically and conveniently, we used support vector machine (SVM) to analyze the correlation between heart rate variability and sleep stage experimentally. R-R intervals (RRIs) from 33 cases of sleep clinical data of Tianjin Thoracic Hospital were extracted and analyzed by principal component analysis (PCA). The SVM method was used to establish the model and predict the five sleep stages. The prediction accuracy of three-sleep-stage was higher than 80%, in contrast to sleep scoring annotations marked by physiological experts based on electroencephalogram (EEG) golden standard. The result showed that there was a good correlation between heart rate variability and sleep staging. This method is an important supplement to the traditional sleep staging method and has a great value for clinical application.
ObjectiveTo analyze the effectiveness of bone grafting through windowing at the femoral head-neck junction for the treatment of osteonecrosis with the segmental collapse of the femoral head. MethodThe clinical data were retrospectively analyzed from 106 patients (131 hips) with osteonecrosis with the segmental collapse of the femoral head who underwent bone grafting through windowing at the femoral head-neck junction between March 2011 and December 2013. There were 78 males and 28 females, with an average age of 31.3 years (range, 17-43 years). The body mass index ranged from 16.5 to 36.5 (mean, 24.2) . There were 53 cases of corticosteroid-induced osteonecrosis of the femoral head (ONFH), 18 cases of alcohol-induced ONFH, and 35 cases of idiopathic ONFH. According to Association Research Circulation Osseous (ARCO) classification system, 105 hips were rated as stage Ⅲa, and 26 hips as stage Ⅲb; according to the China-Japan Friendship Hospital (CJFH) classification system, 41 hips were classified as C+L1 type, 13 hips as L2 type, and 77 hips as L3 type. Harris score was used for the effectiveness evaluation. The clinical failure cases were defined as patients who need total hip arthroplasty, or had a Harris score of less than 70 points. The Cox risk model analysis and Kaplan-Meier survival curves were used for multivariate analysis and univariate analysis. ResultsThe average follow-up period was 27.9 months (range, 4-51 months). Solid fusions of bone graft were observed at 1.0-1.5 years after operation. The Harris score at last follow-up was 81.41±11.93, showing significant difference when compared with preoperative score (63.24±9.98) (t=13.710, P=0.000) . The results were excellent in 5 hips, good in 41 hips, fair in 57 hips, and poor in 28 hips, with an excellent and good rate of 35.1%. Thirty-three hips were classified as clinical failure. A progressive collapse of the femoral head was observed in 22 hips. The single factor analysis showed that preoperative ARCO stage, preoperative CJFH type, and preoperative Harris hip score were risk factors for clinical failure (P<0.05) . The Cox risk model showed that ARCO stage Ⅲb was independent risk factor for clinical failure (P<0.05) . The Kaplan-Meier survival curves showed that ARCO stage Ⅲa patients had a better effectiveness than ARCO stage Ⅲb patients. ConclusionsBone grafting through windowing at the femoral head-neck junction has a good effectiveness in patients at ARCO stage Ⅲa, while patients at ARCO stage Ⅲb and patients of CJFH types L2 and L3 have high clinical failure rates.
ObjectiveTo investigate the effectiveness of one-stage repair and reconstruction of multiple ligament injuries of the knee under arthroscopy. MethodsBetween March 2007 and March 2009,25 patients (25 knees) with multiple ligament injuries of the knee underwent one-stage repair and reconstruction under arthroscopy.Of 25 cases,16 were male and 9 were female with an average age of 29.6 years (range,18-43 years).The causes of injury were traffic accident injury in 20 cases,falling injury from height in 3 cases,and sport injury in 2 cases.The time between injury and surgery was 8-14 days (mean,10.5 days).The preoperative Lysholm score was 37.92±3.57.The X-ray film and MRI examinations showed that 17 patients had tears of anterior cruciate ligament (ACL),posterior cruciate ligament (PCL),and medial collateral ligament,and 8 patients had tears of ACL,PCL,and posterolateral corner (PLC);5 cases had medial meniscus injury and 7 cases had lateral meniscus injury.The ACL,PCL,and PLC were reconstructed under arthroscopy with autologous tendon or allogeneic tendon,and the MCL was repaired.Early active and passive functional exercises were done postoperatively. ResultsAll the incisions healed by first intention,and there was no complications of infection and deep venous thrombosis.Twenty-five patients were followed up 24-78 months (mean,50.9 months).Six patients had knee stiff postoperatively;after manipulation under anesthsia,5 patients lost less than 15° of flexion and only 1 patient lost 26° of flexion.At last follow-up,the stability of the knee joint was significantly improved.There were significant differences in the anterior drawer test,posterior drawer test,Lachman test,and varus stress and valgus stress testing at 30° between at last follow-up and at preoperation (P<0.05).The postoperative Lysholm score was 87.84±4.85,which was significantly better than the preoperative score (t=52.053,P=0.000).The International Knee Documentation Committee (IKDC) rating was nearly normal in 16 cases (64%),abnormal in 8 cases (32%),and obviously abnormal in 1 case (4%). ConclusionOne-stage repair and reconstruction of multiple ligament injuries of the knee under arthroscopy can effectively restore the function of the knee joint,and the effectiveness is reliable.
ObjectiveTo evaluate the effectiveness of double pedicled flap and technique of geometric broken line (GBL) for primary repair of serious dog bite wound. MethodsBetween October 2006 and December 2014, 9 patients with serious dog bite wound were treated. There were 3 males and 6 females with an average age of 34.5 years (range, 8-68 years), and with a mean disease duration of 4 hours (range, 30 minutes to 24 hours). The defect ranged from 1.7 cm×0.5 cm to 15.0 cm×8.0 cm, with the mean depth of 0.5 cm (range, 0.3-0.8 cm). Deep tissue exposure was observed. After routine debridement, a vacuum sealing drainage (VSD) was equipped to suck and irrigate for 1 day, then wound was repaired. The superomedial edge of defect was trimmed, then a GBL shape mainly with square and rectangular was designed. According to defect size, a double pedicled flap was designed at the lateroinferior edge of defect, which size ranged from 1.7 cm×1.5 cm to 18.0 cm×15.0 cm. The donor site was sutured directly. VSD was used for 3 days after operation. ResultsAll flaps survived and wound healed, and donor site incision healed well, with invisible scar. All patients were followed up 6 months to 8 years (mean, 4 years). The wounds were repaired well, and the patients had good facial appearance. No rabies attack was observed during follow-up. ConclusionIt is an ideal repair method to chose double pedicled flap and technique of GBL for primary repair of dog bite wounds. Satisfactory cosmetic appearance can be obtained.