west china medical publishers
Author
  • Title
  • Author
  • Keyword
  • Abstract
Advance search
Advance search

Search

find Author "李坤" 9 results
  • Robotic arm control system based on augmented reality brain-computer interface and computer vision

    Brain-computer interface (BCI) has great potential to replace lost upper limb function. Thus, there has been great interest in the development of BCI-controlled robotic arm. However, few studies have attempted to use noninvasive electroencephalography (EEG)-based BCI to achieve high-level control of a robotic arm. In this paper, a high-level control architecture combining augmented reality (AR) BCI and computer vision was designed to control a robotic arm for performing a pick and place task. A steady-state visual evoked potential (SSVEP)-based BCI paradigm was adopted to realize the BCI system. Microsoft's HoloLens was used to build an AR environment and served as the visual stimulator for eliciting SSVEPs. The proposed AR-BCI was used to select the objects that need to be operated by the robotic arm. The computer vision was responsible for providing the location, color and shape information of the objects. According to the outputs of the AR-BCI and computer vision, the robotic arm could autonomously pick the object and place it to specific location. Online results of 11 healthy subjects showed that the average classification accuracy of the proposed system was 91.41%. These results verified the feasibility of combing AR, BCI and computer vision to control a robotic arm, and are expected to provide new ideas for innovative robotic arm control approaches.

    Release date:2021-06-18 04:52 Export PDF Favorites Scan
  • Choice of Conduit Size and Material for Palliative Right Ventricle-to-Pulmonary Artery Shunt

    Objective To assess clinical results of three different conduit materials (Gore-Tex synthetic graft,bovinejugular vein and autologous pericardium)for palliative right ventricle-to-pulmonary artery (RV-PA) shunt,and explore the correlation between suitable conduit size and patients’ body weight and McGoon ratio. Methods We retrospectively analyzed clinical data of 24 patients with congenital heart diseases who underwent palliative RV-PA shunt in Department of Pediatric Cardiovascular Surgery of Fu Wai Cardiovascular Hospital from July 2010 to July 2012. There were 11 males and 13 females with their age ranging from 60 days to 6 years and body weight of 10.22±7.41 kg. There were 22 patients with pulmonary atresia and ventricular septal defect (PAVSD),1 patient with tetralogy of Fallot (TOF) and 1 patient with doubleoutlet right ventricle (DORV). Among different conduit materials,autologous pericardium was used for 17 patients,Gore-Texsynthetic graft was used for 5 patients,and bovine jugular vein was used for 2 patients. Conduit size and children’s body weight were analyzed with linear regression,then the equation was corrected with McGoon ratio. Results There was no perioperative death. Postoperative percutaneous saturation (SpO2)of the 24 children was 20.37%±28.33% higher than preoperative SpO2 . Electrocardiogram showed sinus rhythm in all the patients. Twenty-three patients were NYHA classⅡ,and 1 patient was NYHA classⅢ. Postoperative mechanical ventilation time of patients with autologous pericardium were significantly shorter than those of patients with other 2 materials (P=0.017). Sixteen patients were followed up from 10 months to 2 years after discharge,including 12 patients with autologous pericardium,3 patients with Gore-Tex synthetic graft and 1 patient with bovine jugular vein. During follow-up,McGoon ratio of patients with autologous pericardium,Gore-Tex synthetic graft and bovine jugular vein were 1.98±0.46,1.83±0.33 and 1.68 respectively,all of which weresignificantly higher than preoperative McGoon ratio (P<0.05). Six patients underwent radical corrective surgery,including5 patients with autologous pericardium and 1 patient with Gore-Tex synthetic graft. There was no complication directly related to surgery during follow-up. Linear regression was performed to form an equation between suitable conduit size and patients’ body weight:conduit diameter (mm)=0.327×body weight (kg)+4.599. McGoon ratio,conduit size and equationresult were compared to find a practical choice of conduit size. If McGoon ratio<0.8,the first integer greater than the equation result could be chosen. If McGoon ratio>1.2,the first integer less than the equation result could be chosen. If 1.2>McGoon ratio>0.8,the first integer either less or greater than the equation result could be chosen. Group analysis showed that patients who recovered better postoperatively were those whose conduit sizes were closer to equation results as well as equation results corrected with McGoon ratio. Conclusion All the 3 materials can be conventionally chosen for RV-PA shunt. Appropriate conduit size can be decided upon patients’ body weight and McGoon ratio for RV-PA shunt.

    Release date:2016-08-30 05:47 Export PDF Favorites Scan
  • 经右侧开胸二期全腔静脉-肺动脉连接术一例

    Release date:2017-12-29 02:05 Export PDF Favorites Scan
  • Study on Whorl Swarming Growth Phenomenon of Proteus Mirabilis

    The present paper is aimed to explore the origins of Proteus mirabilis (PM) whorl swarming growth phenomenon. The whorl swarming growth phenomenon of PM was observed by changed bacterial culture inoculation time, humidity, vaccination practices, cultured flat placement, magnetic field, pH and other factors. Bacterial ring spiral direction of rotation is counterclockwise and the volatile growth process of PM was whorl swarming growth phenomenon. Spiro fluctuation phenomenon was of high frequency in the sealing tanks by cultured anytime inoculation, wherever inoculation technique applied or not, the presence or absence of the magnetic field, and wherever the dish position was. The experimental results showed that the whorl swarming growth phenomenon of PM requires specific pH environment, in which the facts may be relative to its genetic characteristics and the Earth's rotation.

    Release date:2021-06-24 10:16 Export PDF Favorites Scan
  • Effect of Laparoscopic Radical Gastrectomy on Gastrointestinal Motility and Gastrointestinal Hormones in Patients with Gastric Cancer

    ObjectiveTo investigate effect of laparoscopic radical gastrectomy on gastrointestinal motility and gastrointestinal hormones in patients with gastric cancer. MethodsTwo hundred and eighty-nine patients who underwent laparoscopic radical gastrectomy from December 2013 to December 2015 were selected as observation group, 325 patients underwent laparotomy radical gastrectomy during the same period were selected as control group. The postoperative bowel sounds recovery time, the first anal exhaust time, and gastrin, motilin and vasoactive intestinal peptide levels in blood at 12 h before operation and at 24 h after operation were compared between these two groups. ResultsThe baselines had no significant differences between these two groups (P > 0.05). The postoperative bowel sounds recovery time and the first anal exhaust time in the observation group were significantly shorter than those in the control group (P < 0.05). Compared with the levels at 12 h before operation, the gastrin and motilin levels were significantly decreased and the vasoactive intestinal peptide level was significantly increased at 24 h after operation in these two groups (P < 0.05); Compared with the control group, the gastrin and motilin levels at 24 h after operation were significantly increased (P < 0.05) and the vasoactive intestinal peptide level was significantly decreased in the observation group (P < 0.05). ConclusionsPostoperative gastrointestinal motility recovery time in patients undergoing laparoscopic radical gastrectomy is significantly faster than that of laparotomy radical gastrectomy. There is a certain relation between gastrin, motilin or vasoactive intestinal peptide change and operation mode, it might be one of mechanisms of faster recovery of gastrointestinal motility after laparoscopic radical gastrectomy for gastric cancer.

    Release date:2016-10-02 04:54 Export PDF Favorites Scan
  • The timing of chest tube removal after resection of the lung or esophageal cancer: A randomized controlled study

    ObjectiveTo evaluate the timing of chest tube removal after resection of lung or esophageal cancer.MethodsA prospective randomized controlled study was performed. From June 2014 to February 2016, 150 patients suspected with the cancer of lung or esophagus undergoing neoplasm resection and lymph node dissection in our single medical unit were classified into 3 groups according to the random number generated by SPSS17.0 with 50 patients in the each group. The drainage volume for chest tube removal was ≤100 mL/d in the group Ⅰ, 101–200 mL/d in the group Ⅱ, and 201–300 mL/d in the group Ⅲ. Chest radiography was performed 48 hours following chest tube removal. ResultsThe 127 patients (108 males and 19 females, with an average age of 59.0±8.7 years) eligible for analysis consisted of 45 patients in the group Ⅰ, 41 in the group Ⅱ, and 41 in the group Ⅲ respectively after the 23 patients were excluded from this study who were diagnosed as benign lesions through intraoperative frozen pathology (n=20) and postoperative complications (empyema in 2 patients and chylothorax in 1 patient). Age, sex, types of neoplasm, and comorbidities except procedures via video-assisted thoracic surgery (and laparoscopy) showed no significant difference among the three groups (P>0.05). No mortality was observed in this study. There were postoperative complications in 6 patients and its distribution had no statistical differences among the three groups (P>0.05). The mean postoperative duration of chest tube was 181.0±68.2 h, 111.0±63.1 h, 76.0±37.2 h, the mean drainage volume was 1 413.0±500.9 mL, 1 005.0±686.4 mL, 776.0±505.8 mL, and the mean hospital stay time following chest tube removal was 19.0±9.7 d, 14.0±8.0 d, 9.0±4.8 d in the group Ⅰ,Ⅱ and Ⅲ, respectively; there was a significant difference among the three groups (P=0.000). The 13 patients required reintervention after chest tube removal due to pleural effusion accumulation and there was no difference among the three groups (P>0.05). Chest pain relieved essentially after chest tube removal in all patients.ConclusionA drainage volume of ≤300 mL/d as a threshold for chest tube removal after resection of lung or esophageal cancer can shorten postoperative hospital stay and accelerate early recovery of the patients.

    Release date:2019-08-12 03:01 Export PDF Favorites Scan
  • Ultrastructural Effect of High Hydrostatic Pressure and Hypoxia Upon Vasa Vasorum of The Walls of Great Saphenous Vein and Splenic Vein

    ObjectiveTo observe the ultrastructural changes of vasa vasorum endothelial cells in the walls of the great saphenous vein and splenic vein, and to evaluate the effect of high hydrostatic pressure and hypoxia upon vasa vasorum endothelial cells. MethodsThirty-four varicose great saphenous vein samples and splenic vein samples with portal hypertension were obtained, and the same number of normal great saphenous vein and splenic vein were used as the control groups. Semi-thin sections stained with HE staining vasa vasorum of the adventitia in great saphenous vein and splenic vein were observed for light microscopy. Samples were made into ultrathin-slices again. The ultrastructural changes of endothelial cells were observed under transmission electron microscopy. ResultsIn varicose great saphenous veins and diseased splenic veins, the nuclear architecture of endothelial cells in vasa vasorum were integrity and the distribution of chromatin were normal. In some mitochondria, the trachychromatic groundplasm, undefined and ruptured cristae were found. ConclusionUnder high hydrostatic pressure and hypoxia conditions, the ultrastructure of vasa vasorum endothelial cells between the great saphenous vein and the splenic vein may appear remodeling phenomenon, and both changes are similar.

    Release date: Export PDF Favorites Scan
  • Risk factors for deleyed recovery after surgical closure of congenital ventricular septal defect in infants with low weight

    ObjectiveTo reveal the risk factors for delayed recovery and complications in infants with weight≤5.0 kg after surgical ventricular septal defect (VSD) closure.MethodsWe retrospectively reviewed a consecutive series of 86 patients with weight≤5.0 kg who were admitted to our institution for surgical VSD closure between January 2016 and July 2019, including 31 males and 55 females with an age of 17-266 (80.3±40.4) d and a weight of 2.5-5.0 (4.4±0.6) kg. The VSDs were divided into perimembranous (n=65, 75.6%), subaortic (n=17, 19.8%) and subaortic combined muscular types (n=4, 4.7%). Mechanical ventilation (MV) time≥24 h or ICU stay≥72 h were defined as delayed recovery. Death, sudden circulatory arrest, complete heart block requiring a permanent or temporary pacemaker implantation, neurological complications, reoperation (for residue shunt or valvular regurgitation), reintubation and diaphragmatic paralysis were considered as significant major adverse events.ResultsThere was no death, reoperation due to residual VSD or neurological complication. Totally 51 (59.3%) patients had MV timec≥24 h and 51 (59.3%) patients stayed in the ICU≥72 h. Two (2.3%) patients required temporary pacemaker and six (7.0%) patients required reintubation. During the follow-up of 3-36 (15.8±8.8) months, 1 patient died of pneumonia after discharge, 5 patients suffered mild tricuspid valve regurgitation and 1 patient suffered decreased left ventricular systolic function in the follow-up. No aortic valve injuries occurred.ConclusionFor patients whose weight≤5.0 kg, short-term results of surgical VSD closure are excellent. Low weight and age may prolong MV time; low birth weight and pulmonary hypertension may prolong ICU stay, but are not independent risk factors.

    Release date:2021-02-22 05:33 Export PDF Favorites Scan
  • Clinical efficacy of transthoracic occlusion via a right subaxillary incision and conventional surgery in the treatment of ventricular septal defect: A retrospective cohort study

    ObjectiveTo analyze the clinical efficacy of transthoracic occlusion via a right subaxillary incision and conventional surgery in the treatment of ventricular septal defect (VSD).MethodsThe clinical data of patients with congenital VSD undergoing right subaxillary incision surgery in our hospital from January 2017 to January 2020 were retrospectively analyzed. According to the surgical methods, the patients were divided into two groups: a conventional surgery group (conventional group) and a transthoracic occlusion group (occlusion group). There were 221 patients in the conventional group, including 97 males and 124 females, with an average age of 2.6±2.2 years and an average weight of 13.4±6.2 kg; there were 185 patients in the occlusion group, including 90 males and 95 females, with an average age of 3.2±2.6 years and an average weight of 14.7±6.6 kg. The clinical effectiveness was compared.ResultsThe success rate of surgery was 100% in both groups. The intraoperative blood loss was less in the occlusion group (P<0.05). The incision length, operation time, postoperative mechanical ventilation time, retention time in the intensive care unit, the time to resume normal diet and normal activities after operation were all shorter than those in the conventional group (P all <0.05). The total cost during hospitalization of the conventional group was less than that of the occlusion group (P<0.001). There was no statistical difference in the incidence rate of perioperative complications between the two groups (P>0.05). During the follow-up (15.8±8.8 months), the incidence of complications in the conventional group was higher than that in the occlusion group with a statistical difference (P<0.001).ConclusionCompared with conventional surgery, transthoracic occlusion for VSD via right subaxillary incision has the advantages of smaller incision, shorter operation time, less blood loss, shorter postoperative recovery time and less long-term complications. However, the total hospitalization cost is relatively high, mainly because of the high consumables cost, and the long-term effects still need further comparative observation.

    Release date:2021-11-25 03:56 Export PDF Favorites Scan
1 pages Previous 1 Next

Format

Content