1.Constrained ICA and its application to removing artifacts in EEG.
Ansheng GAO ; Yangyu LUO ; Ken CHEN
Journal of Biomedical Engineering 2008;25(3):497-501
Independent component analysis (ICA) is a statistic technique which extracts independent components from a set of standard signals. Since Electroencephalogram (EEG) signals are the mixture of several relatively independent sources, ICA has attracted extensive attention in the field of EEG processing. In this paper, a new Constrained ICA (cICA) algorithm is introduced, it would solve the problem of orderless output when FastICA algorithm is used. The experiment results testify that the cICA algorithm can reduce the effect of different individual when the artifacts of EEG are removed manually. The results also show that the cICA algorithm is robust and performs faster convergence.
Algorithms
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Artifacts
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Brain
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physiology
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Electroencephalography
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methods
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Humans
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Principal Component Analysis
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Signal Processing, Computer-Assisted
2.Analysis of clinical characteristics of discordant structural malformations in one of monochorionic diamnionic twins
Jing WANG ; Jinying LUO ; Jing YANG ; Pengbo YUAN ; Xueju WANG ; Xinlu MENG ; Yangyu ZHAO ; Yuan WEI
Chinese Journal of Obstetrics and Gynecology 2019;54(2):87-92
Objective To analyze the clinical characteristics of structural malformations in one of monochorionic diamnionic twins (MCDA). Methods The clinical data of 77 MCDA patients with structural malformations diagnosed by ultrasound were retrospectively reviewed from January 2012 to May 2017. The distribution of structural malformations, prenatal chromosomal karyotyping and pregnancy outcomes were analyzed. Results (1)Among the 77 MCDA patients with structural malformations, the single malformation accounted for 79%(61/77), the multiple malformations accounted for 21%(16/77). And there were a total of 94 types of malformations, the top three malformations were neurological malformations (32%, 30/94), cardiovascular malformations (29%,27/94) and twin reversed arterial perfusion sequence (TRAPS;10%,9/94). (2)Among the 77 patients with structural malformation, 64 cases (83%, 64/77) were examined for fetal chromosomes, of whom 14 cases (22%,14/64) were examined for fetal chromosomes of both twins, with 1 case (1/14) of discordant fetal chromosome. (3)Among the 77 patients, 4 cases (5%, 4/77) with severe fetal malformations terminated pregnancy. Totally 29 cases (38%, 29/77) with severe malformations were treated with selective fetal reduction, among whom 7 cases (24%, 7/29) experienced unexplained fetal death within 24 hours after the operation;2 cases (7%, 2/29) happened inevitable abortion, and 2 cases (7%, 2/29) underwent unexplained fetal death during the late pregnancy. Of the remaining 44 patients (57%,44/77) with expectant treatment, 13 cases (30%, 13/44) occurred twin transfusion syndrome (Ⅱ-Ⅳ), and were treated with fetoscopic laser occlusion. Eight patients had 2 survival twins, 4 patients delivered 1 survival twin, and 1 patient had dead twins. Conclusions The most common malformations in MCDA twins are the nervous malformations, cardiovascular malformations and TRAPS. The chromosome karyotype of MCDA twins with structural malformations are sometimes discordant, and separate samling of the twins is suggested for prenatal diagnosis. Selective fetal reduction could be given to severe structural malformation in MCDA patients safely and effectively. For non-severe structural malformation in MCDA patients with twin transfusion syndrome, fetoscopic laser occlusion is safe and effective.
3.Simulation method of skull remodellingsurgeryfor infant with craniosynostosis.
Shenyu LU ; Yangyu LUO ; Wenjian ZHENG ; Jian GONG
Journal of Biomedical Engineering 2021;38(5):932-939
Craniofacial malformation caused by premature fusion of cranial suture of infants has a serious impact on their growth. The purpose of skull remodeling surgery for infants with craniosynostosis is to expand the skull and allow the brain to grow properly. There are no standardized treatments for skull remodeling surgery at the present, and the postoperative effect can be hardly assessed reasonably. Children with sagittal craniosynostosis were selected as the research objects. By analyzing the morphological characteristics of the patients, the point cloud registration of the skull distortion region with the ideal skull model was performed, and a plan of skull cutting and remodeling surgery was generated. A finite element model of the infant skull was used to predict the growth trend after remodeling surgery. Finally, an experimental study of surgery simulation was carried out with a child with a typical sagittal craniosynostosis. The evaluation results showed that the repositioning and stitching of bone plates effectively improved the morphology of the abnormal parts of the skull and had a normal growth trend. The child's preoperative cephalic index was 65.31%, and became 71.50% after 9 months' growth simulation. The simulation of the skull remodeling provides a reference for surgical plan design. The skull remodeling approach significantly improves postoperative effect, and it could be extended to the generation of cutting and remodeling plans and postoperative evaluations for treatment on other types of craniosynostosis.
Child
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Computer Simulation
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Cranial Sutures/surgery*
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Craniosynostoses/surgery*
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Humans
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Infant
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Skull/surgery*