GE 0.35T Ovation HD2例故障维修

故障一:扫描孔照明灯不亮。故障分析:(1)如图1所示,按下灯开关,检测系统电源输出(SSM)J34电缆的1,2,3脚和2,4,6脚,没有灯的电源输出。(2)进入维修菜单,做磁体控制面板回路测试:测试结果显示系统柜收到控制面板给出的信号并可以正确识别,由此可以确定系统柜前端全部正常。(3)检查系统电源输出(SSM)的J32电缆,这根电缆是从系     

功能性相对椎旁肌横截面积对腰椎间盘突出症的诊断价值及与椎间盘退变的关系

研究功能性相对椎旁肌横截面积对腰椎间盘突出症（LDH）的诊断价值及与椎间盘退变的关系。方法 选取2020年6月—2023年8月,以LDH收治入我院的96名患者为观察组;选取同期行腰椎MRI的50名体检者（无腰椎退行性疾病）作为对照组。根据Pfirrmann分级将观察组L4/L5和L5/S1层面椎间盘进行分级;使用ImageJ软件测量2组研究对象椎旁肌横截面积、肌肉脂肪化横截面积和椎间盘横截面积,并计算对应层面功能性相对椎旁肌横截面积。比较2组研究对象功能性相对椎旁肌横截面积;采用受试者工作特征（ROC）曲线分析功能性相对椎旁肌横截面积对LDH的诊断价值;比较不同椎间盘退变程度等级患者对应的功能性相对椎旁肌横截面积;分析椎间盘退变程度等级与功能性相对椎旁肌横截面积的相关性并分析功能性相对椎旁肌横截面积的影响因素。结果 对照组研究对象L5/S1、L4/L5层面功能性相对椎旁肌横截面积均大于观察组,差异均有统计学意义（P＜0.05）。观察组不同椎间盘退变程度等级患者的功能性相对腰大肌横截面积、功能性相对多裂肌横截面积、功能性相对竖脊肌横截面积差异均有统计学意义（P＜0.05）。相关分析结果显示,在L5/S1平面上,功能性相对腰大肌横截面积、功能性相对多裂肌横截面积、功能性相对竖脊肌横截面积与腰椎间盘退变程度等级的相关系数rs值分别为-0.388、-0.344、-0.360（P＜0.001）;在L4/L5平面上,功能性相对腰大肌横截面积、功能性相对多裂肌横截面积、功能性相对竖脊肌横截面积与腰椎间盘退变程度等级的相关系数rs值分别为-0.500、-0.489、-0.501(P＜0.001)。在L5/S1平面,功能性相对腰大肌横截面积、功能性相对多裂肌横截面积、功能性相对竖脊肌横截面积诊断LDH的曲线下面积（AUC）分别为0.892（95% CI：0.830~0.937）、0.911（95% CI：0.852~0.951）、0.640（95% CI：0.557~0.718）;在L4/L5平面上,功能性相对腰大肌横截面积、功能性相对多裂肌横截面积、功能性相对竖脊肌横截面积诊断LDH的AUC分别为0.850（95% CI：0.782~0.904）、0.919（95% CI：0.862~0.958）、0.848（95% CI：0.780~0.902）。回归分析结果显示,腰椎间盘退变程度等级是功能性相对椎旁肌横截面积的独立影响因素（P＜0.05）。结论 功能性相对椎旁肌横截面积对临床LDH的诊断具有重要参考价值,且其与椎间盘退变程度等级存在负相关,同时腰椎间盘的退变是椎旁肌退变的独立影响因素。     

SIEMENS SOMATOM PLUS4 CT电源故障检修4例

故障１开机自检约２分钟后 ,显示器显示ｃａｎ＇ｔｏｐｅｎｋｅｙｂｏａｒｄ，ｋｅｙｂｏａｒｄｉｓｎ＇ｔｐｒｅｓｅｎｔ，ｔｙｐｅｔｔｙ…… ,出现死机现象。故障检修由现象提示可知 ,主机自检时找不到键盘。导致此故障现象有三种可能 :(１)键盘电缆连接不好 ;(２)键盘电源损坏 ;(３)键盘损坏。检查键盘电缆连接状况 ,接触良好 ,测量键盘供电电源Ｅ８０１ ,输入２３０ＶＡＣ正常 ,无±１２ＶＤＣ输出 ,测量结果表明Ｅ８０１损坏 ,更换Ｅ８０１电源 ,故障排除。故障２开机正常运转约２０分钟后 ,Ｇａｎｔｒｙ控制面板指示灯熄灭 ,系统请求…     

血透机维修数例及相关的预防措施

1故障现象一百特SPS550血透机,面板无显示,但除气泵和透析压力泵运转。故障分析检修:从故障现象分析,应该是电源电路的问题,因此重点检查电源供应板(代号PC1B)。查±12V,正常;查+5V,电压为零。查PC1B板的+5V电源电路桥堆BR3、Q3、Q4、Q2,基本无击穿或短路;由此怀疑可能为负载短路导致保护电路动作,+5V无输出。测量+5V的负载阻抗,接近0Ω;+5V的供电范围很广,都是有一根扁平电缆分至各电路。逐个拔出接插头测量+5V的负载阻抗,直至阻抗不再为零。查看此接插头所连接的电路板,是肝有打火发黑的痕迹。用刀片清除锈蚀的附着物后重焊各焊…     

ABL—30型血气分析仪打印机电源电路故障检修

ＡＢＬ－３０型血气分析仪是丹麦国早期生产的一种分析仪。由于机型老，因此，机器本身的自检数据和对血样本的监测结果是靠打印机来完成的。如果打印部分出现故障，整机就无数据输出。因此打印机的电源电路是很重要的电路之一。故障现象：开机后打印机不工作。（正常时开机就有部分数据打出），而且经十分钟后，打印机线包发烫，同时发现打印机电路中的ＢＤ６４７电源调整管温度很高。故障分析：出现以上现象原因有两种：１．打印机线包匝间短路；损坏阻抗变小，电流过大，造成电源负载过重，使输出电压降低，调整管过热。２．打印机供电源…     

关于医院医疗设备配备备用电源的探讨

阐述为防止意外停电带来的医疗风险,医院需要配备后备电源。针对目前医用后备电源有UPS、EPS和柴油发电机3种选择,介绍了3种后备电源的原理,解决如何配备问题,保证急救医疗设备供电系统的安全可靠。     

电源缺相保护器设计

1概述该保护器是作为电源在缺单相或多相时,能够自动保护负载停止工作,达到保护机器的目的。目前,应用三相电源的机器较多,由于电源负载过重常常有缺相现象。为了保护机器,我们设计了这台保护器。该机具有体积小、造价低、使用广、维护方便等特点,能在电源缺一相或多相的情况下     

＋5V开关电源用于应急替换

在维修超声波仪器时，经常遇到电源出现故障造成整机不工作或出现一部分功能不正常，在检测电源时，超声波电源部分有多组直流电源，如 12V,供给显示器。 5V供给全部集成电路工作电源。还有一组直流高压电源 30V～ 160V电源供给不同功能探头晶振起振电源。 5V电源由于功耗大，从电源配给上输出多组 5V电源分别供给不同部位，因此，测量时可出现多组 5V电源从0．5A至80A。     

论医院电源系统的安全保障

电源系统是医院运行的生命线,正确地使用电源,合理地分配电源以及保障供电系统的安全是非常重要的一环,而接地系统是安全保障的一个关键,此外设备电源的抗干扰,设备之间通讯连接的抗干扰问题都是需要注意的。本文就医院的设备电源系统的安全保障,讨论电源故障的产生及防护措施。     

CT机检测器电源和DAS电缆故障检修分析

故障现象我院SIEMENSSOMAOMHiQCT机在扫描曝光后 ,图像屏显示多个同心圆状的伪影像 ,而四角标识字符显示正常。打开扫描架直观所见 ,气体检测器电源E4H(D40板)的红、绿指示灯皆熄灭 ,正常状态应为绿色指示灯燃亮。检修原图略拔下气体检测器电源板(D40板)的直流 -200V的正、负极输出电缆 ,用万用表直流电压挡检测D40板的输出电压为零 ,拔下D40板的交流220V的输入电缆插头X5 ,用万用表的交流电压挡检测插脚X5 -1和X5 -4间的输入电压为330V ,显然电压过高。从母槽上拔出D40板取下F1保险丝 ,用万用表的欧姆挡检测保险丝已熔断 ,更…     

Reference values of the bioelectrical impedance vector in neonates in the first week after birth

OBJECTIVE: To determine the reference, bivariate, tolerance intervals of the whole-body impedance vector for healthy white neonates, we performed an observational, cross-sectional study in two university hospitals. METHODS: The impedance vector (standard, tetrapolar analysis at 50-kHz frequency) was measured in 163 consecutive subjects (87 boys and 76 girls) with postnatal ages of 1 to 7 d. Bivariate vector analysis was conducted with the resistance-reactance (RXc) graph method. RESULTS: The age-specific 95% confidence intervals of mean vectors and the 95%, 75%, and 50% tolerance intervals for individual vector measurements were plotted using R and Xc components standardized by the subject's crown-to-heel length (height). Mean vectors from the groups (1, 2, and 3 to 7 d) with overlapping 95% confidence ellipses were considered representative of only one age class of 1 to 7 d. The impedance vector distribution of neonates also was compared with healthy white children (1014 boys and 1030 girls, age 2-15 y) and adult subjects (354 men and 372 women, age 15-85 y) from the same geographic area. There was a definite, progressive, vector shortening from birth, through ages 2 to 15 y, toward the adults' vector position. CONCLUSIONS: We established the reference, bivariate, 95%, 75%, and 50% tolerance intervals of the impedance vector in the first postnatal week for healthy white neonates, with which the vectors from infants with altered body composition can be tested (free software is available from apiccoli@ unipd.it).     

Normal values of the bioelectrical impedance vector in childhood and puberty

The purpose of this study was to determine the reference, bivariate, and tolerance intervals of the whole-body impedance vector in Italian children. This was a cross-sectional, multicenter study, and participants were chosen from the general school population. The impedance vector (standard, tetrapolar analysis at 50-kHz frequency) was measured in 3110 subjects, ages 2 to 15 y, and 2044 healthy children (1014 male and 1030 female) with weight and height within the 95th percentile were selected for the analysis (resistance-reactance graph method). The age-specific 95% confidence intervals of mean vectors and the 95%, 75%, and 50% tolerance intervals for individual vector measurements were plotted using resistance and reactance components standardized by the subject's height. Mean vectors from both sexes with separate 95% confidence ellipses were considered as representative of eight different age groups, from 2 to 13 y. There was a statistically significant sex effect on vector distribution from boys and girls in the age group of 14 to 15 y. The impedance vector distribution of children was also compared with healthy adult subjects (354 male and 372 female, age 15 to 85 y). There was a progressive, statistically significant vector shortening from age 2 to 15 y toward the adults' vector position. In conclusion, we established the trajectory followed by the mean impedance vector in children over ages 2 to 15 y and also obtained the reference, bivariate, and 95%, 75%, and 50% tolerance intervals of the impedance vector by age for healthy children, with which the vectors from children with altered body composition can be tested.     

Detection of segmental internal fat by bioelectrical impedance analysis in a biological phantom

OBJECTIVE: Quantification of internal adipose tissue such as visceral adipose tissue currently relies on expensive, cross-sectional imaging modalities. The purpose of this study was to test the hypothesis that surface impedance, determined by bioimpedance analysis, might be used to predict regional internal fat content change in a phantom model. METHODS: Fresh hollowed-out cucumbers were used as cylindrical biological phantoms to test this hypothesis. After removal of the seeds, the cucumbers were filled with normal saline, mixture of saline and corn oil, or porcine adipose tissue bathed in saline. Surface resistance and reactance were measured with a bioimpedance analyzer accurate to 0.1 Omega (Quantum 10X, RJL Systems), and impedance was calculated. A linear regression model was used to interpret the association between composition and impedance. RESULTS: Surface impedance varied linearly with changes in the relative internal corn oil portions (r- = 0.98). A similar relation was noted with porcine adipose tissue bathed in saline (r(2) = 0.95) regardless of the specific position of adipose tissue within the cucumber. CONCLUSION: Surface impedance measured by bioimpedance analysis can detect variations in fat content in the interior of a cylindrical phantom.     

Bioelectrical impedance vector distribution in the first year of life

OBJECTIVE: We assessed the bioelectrical impedance vector distribution in a sample of healthy infants in the first year of life, which is not available in literature. METHODS: The study was conducted as a cross-sectional study in 153 healthy Caucasian infants (90 male and 63 female) younger than 1 y, born at full term, adequate for gestational age, free from chronic diseases or growth problems, and not feverish. Z scores for weight, length, cranial circumference, and body mass index for the study population were within the range of +/-1.5 standard deviations according to the Euro-Growth Study references. Concurrent anthropometrics (weight, length, and cranial circumference), body mass index, and bioelectrical impedance (resistance and reactance) measurements were made by the same operator. Whole-body (hand to foot) tetrapolar measurements were performed with a single-frequency (50 kHz), phase-sensitive impedance analyzer. The study population was subdivided into three classes of age for statistical analysis: 0 to 3.99 mo, 4 to 7.99 mo, and 8 to 11.99 mo. Using the bivariate normal distribution of resistance and reactance components standardized by the infant's length, the bivariate 95% confidence limits for the mean impedance vector separated by sex and age groups were calculated and plotted. Further, the bivariate 95%, 75%, and 50% tolerance intervals for individual vector measurements in the first year of life were plotted. RESULTS: Resistance and reactance values often fluctuated during the first year of life, particularly as raw measurements (without normalization by subject's length). However, 95% confidence ellipses of mean vectors from the three age groups overlapped each other, as did confidence ellipses by sex for each age class, indicating no significant vector migration during the first year of life. CONCLUSIONS: We obtained an estimate of mean impedance vector in a sample of healthy infants in the first year of life and calculated the bivariate values for an individual vector (95%, 75%, and 50% tolerance ellipses).     

Assessment of fat-free mass from bioelectrical impedance analysis in men and women with Prader-Willi syndrome: cross-sectional study

We have recently shown that population-specific formulae are required to estimate fat-free mass (FFM) from bioelectrical impedance analysis (BIA) in obese women with Prader-Willi syndrome (PWS) matched by age and percent fat mass (FM) to non-PWS women. The present cross-sectional study was aimed at developing generalised BIA equations that could be used in PWS subjects independently of sex and FM. We used dual-energy X-ray absorptiometry to measure FFM and BIA to measure whole-body impedance at 50?kHz (Z₅₀) in 34 women and 21 men with PWS. The impedance index, that is, height (cm)²/Z₅₀ (Ω), explained 77% (BCa-bootstrapped 95% CI 65 to 85%) of the variance of FFM with a root mean squared error of the estimate of 3.7?kg (BCa-bootstrapped 95% CI 3.2 to 4.5?kg). BIA can be used to estimate FFM in obese and non-obese PWS men and women by means of population-specific equations.     

Evaluation of a new bioelectrical impedance instrument for the prediction of body cell mass independently of height or weight

The objective of the present study was to evaluate the performance of a new bioelectrical impedance instrument, the Soft Tissue Analyzer (STA), which predicts a subject's body composition. A cross-sectional population study in which the impedance of 205 healthy adult subjects was measured using the STA. Extracellular water (ECW) volume (as a percentage of total body water, TBW) and fat-free mass (FFM) were predicted by both the STA and a compartmental model, and compared according to correlation and limits of agreement analysis, with the equivalent data obtained by independent reference methods of measurement (TBW measured by D(2)O dilution, and FFM measured by dual-energy X-ray absorptiometry). There was a small (2.0 kg) but significant (P < 0.02) difference in mean FFM predicted by the STA, compared with the reference technique in the males, but not in the females (-0.4 kg) or in the combined group (0.8 kg). Both methods were highly correlated. Similarly, small but significant differences for predicted mean ECW volume were observed. The limits of agreement for FFM and ECW were -7.5-9.9 and -4.1-3.0 kg, respectively. Both FFM and ECW (as a percentage of TBW) are well predicted by the STA on a population basis, but the magnitude of the limits of agreement with reference methods may preclude its usefulness for predicting body composition in an individual. In addition, the theoretical basis of an impedance method that does not include a measure of conductor length requires further validation.     

Body composition in older orthopaedic rehabilitation inpatients: Are field methods valid?

Aim: The assessment of body composition is an important aspect of the determination of nutritional health. This cross-sectional measurement study aimed to assess the relative validity of a range of field techniques for the measurement of body composition in a sample of older orthopaedic inpatients participating in rehabilitation. Methods: Assessment of percent fat-free mass of 31 adults, aged 65 years and over, was conducted under fasting conditions by two types of bioelectrical impedance analysis (multi-frequency and single frequency—using manufacturer's pre-programmed prediction equation) and compared with percent fat-free mass estimated by dual energy X-ray absorptiometry, a reference technique. Data from multi-frequency bioelectrical impedance analysis were also used to calculate percent fat-free mass from the prediction equation of Dey et al. for comparison. Skeletal muscle mass was derived from assessment of corrected arm muscle area and compared with skeletal muscle mass from dual energy X-ray absorptiometry analysis. Bland-Altman analysis was performed to determine the level of agreement between each field technique and dual energy X-ray absorptiometry. Results: Mean bias and limits of agreement between single frequency bioelectrical impedance analysis and dual energy X-ray absorptiometry were −5.7% (−24.0, 12.6), between multi-frequency bioelectrical impedance analysis (manufacturer's pre-programmed prediction equation) and dual energy X-ray absorptiometry were 1.4% (−13.4, 16.1), between multi-frequency bioelectrical impedance analysis (Dey et al. prediction equation) and dual energy X-ray absorptiometry were −5.0% (−16.6, 6.6) and between skeletal muscle mass as derived from assessment of corrected arm muscle area and skeletal muscle mass from dual energy X-ray absorptiometry analysis −0.97 kg (−8.37, 6.43). Conclusion: None of the methods assessed are clinically acceptable for assessment of body composition in older orthopaedic rehabilitation patients; however, estimation of skeletal muscle mass, as derived from corrected arm muscle area, is likely to be of more use in the clinical setting as there is no requirement for patients to be fasted.     

腹膜透析患者内脏脂肪和血管内皮功能的关系

目的探讨腹膜透析患者内脏脂肪与血管内皮功能的关系。方法收集88例腹膜透析患者的一般临床资料,采用多频生物电阻抗分析(BIA)法和血流介导的肱动脉扩张(FMD)法分别评估总体脂肪率、内脏脂肪和血管内皮功能。结果腹透患者中有44.3%超重或肥胖,腹透患者脂肪的分布与年龄、性别相关,多元回归分析表明内脏脂肪量和糖负荷是内皮功能的独立影响因素(调整的R2=0.180,P<0.01)。结论内脏脂肪是腹透患者血管内皮功能的独立预测因素。     

脂肪测量器的应用价值探讨

目的用生物电阻抗方法测量全身和分段阻抗,与脂肪测量器测量结果对分析,以探讨脂肪测量器测量结果的应用价值。方法 应用生物阻抗法测量人体上、下肢他段阻抗;采用人体脂肪测量器测量人体脂肪含量。结果人体上肢生物电阻抗值与人体脂肪测量器测得的脂肪含量有着较好的线性关系,下肢和全身生物电阻抗值与人体脂肪测量器测得的脂肪含量相关性较差。结论脂肪测量器测得的脂肪含量能准确指示人体上半身脂肪率,不能作为人体总脂肪测量值。     

Interchangeability among the percentages of body fat estimated by mid-arm adipose area,triceps skinfold thickness and arm-to-arm segmental bioimpedance analysis

BACKGROUND: Assessing nutritional status based on the upper limbs is useful at the clinical level. The aim of this study is to evaluate the agreement degree of the body fat percentages (%BF) estimated by the mid-arm adipose area (%BFARM), the Siri triceps skin-fold equation (%BFTRICEPS) and the arm-to-arm segmental bioimpedance analysis (%BFBIA), as well as the Siri four-skinfold equation (%BFSIRI), assessing their interchangeability. METHODS: A cross-sectional study. Body fat assessments were made on a total of 145 subjects (83 males, 62 females) anthropometrically and by bioelectrical impedance analysis (Omron BF 300). The agreement between methods were analyzed using the interclass correlation coefficient (ICC) and the Bland-Altman method. RESULTS: The ICC between %BFARM and %BFTRICEPS was 0.8322 (CI .95% 0.7672-0.8791); between %BFARM-%BFBIA 0.7337 (0.6305-0.8080) and between %BFTRICEPS-%BFBIA 0.9290 (0.9015; 0.9488). For the Bland-Altman method, the agreement interval between %BFARM-%BFTRICEPS (-11.2; 16.96) and between %BFARM-%BFBIA (-13.04; 21.76) exceeded the cutoff point (+/- 10%), but not between %BFTRICEPS-%BFBIA (-6.64; 9.6), %BFSIRI-%BFTRICEPS (-5.27; 4.52) and %BFSIRI-%BFBIA (-6.31; 8.52). The BMI has no bearing on the results. CONCLUSIONS: The method utilized influences the nutritional assessment made based on the upper limbs. The mid-arm adipose area method overestimated the %BF with relationship to the Siri triceps skinfold or four-skinfold equation and to the bioelectrical impedance analysis, and although this result suggests that mid-arm adipose area may not be a good indicator of global adiposity, this must be confirmed against a gold standard.