1.Comparison of Performances of Ag/AgCl Coating Electrodes and Pulverized Electrodes in Cerebral Application of Electrical Impedance Tomography
Meng DAI ; Xiuzhen DONG ; Fusheng YOU ; Xuetao SHI ; Canhua XU
Chinese Medical Equipment Journal 2004;0(09):-
Objective To compare the performance of novel Ag/AgCl pulverized electrodes with conventional Ag/AgCl coating electrodes in cerebral application of Electrical Impedance Tomography(EIT).Methods Based on the EIT system developed by our group,raw data were measured on a phantom and an adult volunteer,with Ag/AgCl coating electrodes and pulverized electrodes,respectively.The performances of electrode systems were evaluated in contact impedance and two other figures(the high-frequency SNR,HFSNR;the low-frequency SNR,LFSNR).Results Ag/AgCl pulverized electrode plays a better performance in resisting noise and keeping stabilization.Conclusion Ag/AgCl pulverized electrode develops the needs of imaging and monitoring human brains in EIT more availably.
2.Method for obtaining prior information of electrical impedance tomography
Canhua XU ; Xiuzhen DONG ; Cheng ZHEN ; Feng FU ; Wanjun SHUAI
Chinese Medical Equipment Journal 1989;0(01):-
The reverse problem of Electrical impedance tomography(EIT) is a highly ill-posed problem.It is concluded that spatial prior information could improve the final image quality.This paper proposes a new method for obtaining prior information.By this method,the inspected cross-section contour and internal structure for EIT can be achieved.
3.Comparison of Performances of Three Kinds of Direct Current Power Source in the Application of Electrical Impedance Tomography(EIT)
Jieshi MA ; Xuetao SHI ; Canhua XU ; Meng DAI ; Xiuzhen DONG
Chinese Medical Equipment Journal 2003;0(11):-
Objective To provide the hardware system of EIT with an excellent direct current(DC) power source. Methods The spectrums of the outputs of DC power source and the driving source were analyzed by means of Spectrum Analyzer- E4408B when EIT system was respectively powered by battery, linear power source and switching power source. Based on the numbers and power levels of the spurs of the three power sources and the numbers and power levels of the interferences within the driving source, the influence of the three power sources on the error of measuring was estimated. Meanwhile the EIT system did data acquisition, the overall signal-to-noise-ratio(SNR) of the three power sources at the 18 frequencies were calculated and the influence of the three power sources on the error of measuring was judged. Results With respect to the numbers and power levels of the interferences within the driving source when EIT was powered respectively by the three power sources, the battery output 6 interferences, the highest power of which achieved -78.25 dBm; the linear power source output 6 interferences, the highest power of which achieved -67.11 dBm; the switching power source output 15 interferences, the highest power of which achieved -35.83 dBm. The overall SNRs of the battery at the 18 driving frequencies were higher than that of the linear power source, and the overall SNRs of the linear power source were higher than that of the switching power source. Conclusion The power mode of battery is the best for the hardware of EIT among the three power sources.
4.The study on the job stressors of nurses employed in military hospitals and relationship between job stressors and demography characters
Xi XU ; Song ZHANG ; Canhua XIAO ; Meirong HU
Chinese Journal of Practical Nursing 2006;0(12):-
Objective This study was conducted to describe job stressors of nurses employed in military hospitals and relationship between job stressors and demography characters.Method 296 employed nurses were investigated by nurse job stressor questionnaires.Result Professional and career issues were the most frequently encountered job stressor among employed nurses,the other stressors in descending order were workload and time pressure,patient care and interaction,resource and environmental problems,management issues.Job stressors of nurses could be influenced by their age,job title,et al.Conclusion The finding suggest that effective stress management strategies should be relieve job stress.
5.Efficacy comparison of three different treatment of internal fixation of intervetebral crasis on spinal cord cervical spondylosis
Canhua XU ; Zenghui WU ; Zhi ZHENG ; Qingshun ZHANG
Chongqing Medicine 2015;(31):4345-4348
Objective To observe the difference of efficacy of three different treatment of internal fixation of intervetebral crasis on cervical spondylosis (spinal cord) .Methods From January 2009 to January 2013 ,There are 167 cases of patients admitted to hospital from cervical spondylosis (spinal cord ) ,randomly selected different fusion fixation methods are divided into three groups :in the first group ,there were 55 patients treated with autologous iliac bone graft fusion plate fixation ;in the second group , there were 60 patients treated with zero profile material PEEK interbody fusion with autologous bone graft ;in the third group ,the 52 patients were treated with the PEEK material MC + self‐locking cervical interbody fusion with autologous bone graft .Observa‐tion and comparison indicators include :spinal cord function JOA scores before and after surgery ,surgical segment intervertebral height and cervical curvature condition .Results Follow‐up lasted from 13 to 50 months ,the average length was 26 months .The difference in operation time ,blood loss during surgery analysis ,wherein the first group and the second or third group of three groups was statistically significant (P<0 .05) ,the difference between the second group and the third group was not statistically significant (P>0 .05) .In the first group ,there were 17 patients had transient throat discomfort and symptom disappeared 48 hours later ;dysphagia relieved or disappeared in one week ;there were two cases of screws and titanium loosen one week after operation , and were treated with immediate revision surgery .In the second ,third group ,there were 19 cases and 13 cases showed temporary throat discomfort disappeared within 48 hours after surgery respectively ,there was no dysphagia .No patient experienced cerebrospi‐nal fluid leakage ,hematoma and wound infection .The postoperative JOA scores spinal cord function (17 points France) ,surgical segmental cervical intervertebral height and curvature of three groups improved significantly compared with preoperative evaluation index ,and there was no significant difference among three groups (P>0 .05) .In the last follow‐up ,the interbody fusion rates of the first ,second and third groups were 67 .1% ,66 .3% and 65 .9% ,the difference between groups was not statistically significant (P>0 .05) .Conclusion Anterior decompression and interbody fusion locking device applications showed good performance in maintai‐ning the intervertebral height segment surgery ,rehabilitation cervical curvature ,and promote bone fusion with autogenous titanium plate fixation comparison .Patients can get a good surgery ,and the former has a simpler surgical fixation method ,shorter time ,less bleeding and less complications .
6.A multifrequency time-difference electrical impedance tomography algorithm using spectral constraints.
Lu CAO ; Bin YANG ; Haoting LI ; Xuechao LIU ; Benyuan LIU ; Canhua XU ; Ruigang LIU ; Feng FU
Journal of Biomedical Engineering 2020;37(1):80-86
This study aims to propose a multifrequency time-difference algorithm using spectral constraints. Based on the knowledge of tissue spectrum in the imaging domain, the fraction model was used in conjunction with the finite element method (FEM) to approximate a conductivity distribution. Then a frequency independent parameter (volume or area fraction change) was reconstructed which made it possible to simultaneously employ multifrequency time-difference boundary voltage data and then reduce the degrees of freedom of the reconstruction problem. Furthermore, this will alleviate the illness of the EIT inverse problem and lead to a better reconstruction result. The numerical validation results suggested that the proposed time-difference fraction reconstruction algorithm behaved better than traditional damped least squares algorithm (DLS) especially in the noise suppression capability. Moreover, under the condition of low signal-to-noise ratio, the proposed algorithm had a more obvious advantage in reconstructions of targets shape and position. This algorithm provides an efficient way to simultaneously utilize multifrequency measurement data for time-difference EIT, and leads to a more accurate reconstruction result. It may show us a new direction for the development of time-difference EIT algorithms in the case that the tissue spectrums are known.
7.Oral squamous cell carcinomas: state of the field and emerging directions.
Yunhan TAN ; Zhihan WANG ; Mengtong XU ; Bowen LI ; Zhao HUANG ; Siyuan QIN ; Edouard C NICE ; Jing TANG ; Canhua HUANG
International Journal of Oral Science 2023;15(1):44-44
Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.
Humans
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Carcinoma, Squamous Cell/therapy*
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Squamous Cell Carcinoma of Head and Neck
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Mouth Neoplasms/therapy*
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Head and Neck Neoplasms
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Tumor Microenvironment