The Correlation between the Response Thresholds of ASSR and Pure Tone Thresholds in Young Deaf Children / 听力学及言语疾病杂志

Objective To investigate the correlation between auditory steady-state response (ASSR)and behavioral audiometry threshold in deaf children.Methods A total of 63 cases (126 ears)of severely and profoundly hearing impaired children from 0.5 years to 6 years were divided to Group A of 0.5~1.0 years,Group B of 1.1~3.0 years and Group C of 3.1~6.0 years old.ASSR and behavioral hearing tests were conducted in the sound field. 0.5~1.0 years old children were tested with the behavior observation Audiometry (BOA),1~2 years old children with visual reinforcement audiometry (VRA),while those of 3 ~6 with play audiometry (PA).Results For the ASSR response thresholds and pure tone hearing thresholds at 0.5,1,2 and 4 kHz,the correlation coefficients were 0.75,0.76,0.76,and 0.83,respectively.There was a significant correlation (P <0.01 ).The hearing thresholds were generally lower than the ASSR response thresholds,and with increasing frequency,the gaps were narrowed between the two.For Group A at each frequency the response thresholds and behavioral audiometry correlations were lower than those of Group B and C with the lowest at 0.5 kHz.Conclusion For the children of 0.5~6 years, ASSR and behavioral audiometric thresholds have good correlations.ASSR can provide information about the behav-ior thresholds for young children and those high risk children and for fitting hearing aids.

Estimating the body volume status in maintenance hemodialysis children with multi-frequency bioelectrical impedance / 中华实用儿科临床杂志

Objective To evaluate the body volume status in maintenance hemodialysis(MHD) children with multi-frequency bioelectrical impedance.Methods Nine end-stage-renal-disease patients undergoing MHD from Aug.2011 to Mar.2012 in blood purification department of Beijing Children's Hospital and 171 cases of healthy control group were investigated.Over hydration (OH),total body water(TBW),extracellular water(ECW),i ntracellular water (ICW) of MHD children pre-and post-hemodialysis and healthy children were measured with the body composition monitor which was based on multi-frequency bioelectrical impedance and the values were standardized by body weight to produce TBW％,ECW％ and ICW％.Results There were statistical differences of OH,TBW,ECW and ECW％ before and after dialysis,but no statistical difference of ICW.By contrast,ECW％ values pre-dialysis were higher,but post-dialysis were lower than that of healthy control group.Pre-and post-dialysis ICW％ values in HD children were similar to those of healthy control group.Conclusions ECW％ increased in MHD children;the main function of normal hemodialysis is to remove extra ECW,which has little effect on ICW.The measurement of multi-frequency bioelectrical impedance can provide an objective basis for capacity status.

Usefulness of Colored 3D Imaging of Respiratory Impedance in Asthma

PURPOSE: Recently, the clinical application of the forced oscillation technique (FOT) has progressed with the spread of commercially available FOT devices, including the impulse oscillation system and MostGraph. We investigated the usefulness of color 3D imaging of respiratory impedance in asthma using MostGraph. METHODS: Whole-breath and within-breath respiratory system resistance (Rrs) and reactance (Xrs) were measured in 78 patients with asthma. Color 3D images were classified into three patterns: the chronic obstructive pulmonary disease (COPD)-like pattern (high values of Rrs and Xrs with a marked respiratory cycle and frequency dependence), the asthma pattern (moderately high Rrs over the entire frequency and a respiratory cycle with slight Xrs changes), and a normal-like pattern (low Rrs and Xrs with few within-breath changes). The classification was performed by three researchers, who were unaware of the clinical information, and the clinical characteristics were compared among the three groups. RESULTS: Color 3D imaging provided a COPD-like pattern in 25 patients, an asthma pattern in 39 patients, and a normal-like pattern in 14 patients. Patients with the COPD-like pattern were predominantly female with a higher body mass index, lower forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), and higher Rrs and Xrs values (whole-breath and within-breath variation). Those with the normal pattern had higher FEV1 and FVC, and a lower single-breath nitrogen washout slope. There were no differences in asthma control or exhaled nitric oxide levels among the three groups. CONCLUSIONS: These results suggest that color 3D imaging of respiratory impedance may show asthma phenotypes.

ACCURACY OF ESTIMATING HUMAN BODY COMPOSITION CHANGES ON BI METHODS -WITH THE STUDY OF SERIAL MEASUREMENTS DURING THE WEIGHT / 体力科学

The purpose of this study was to investigate the accuracy of estimating human body composition changes using bioelectrical impedance (BI) methods during a weight-loss intervention. Subjects were forty-three obese men (age : 49.2±10.5 yr, BMI : 27.8±1.7 kg/m²) who completed a 14-week weight-loss intervention. In all subjects, fat mass (FM) and fat-free mass (FFM) were assessed by dual energy x-ray absorptiometry (DXA) as well as single- and multi-frequency BI methods (SBIM, MBIM) before and after the intervention. Resistance parameters were measured by SBIM and MBIM (SBIM : R₅₀ ; MBIM : R∞, R0, and Rfc). In nine subjects these variables were also measured at weeks 1 and 4. Weight decreased (P<0.05) by -8.0±3.2 kg during the intervention while FFM changes averaged -0.4±1.6 kg (DXA), -2.0±1.5 kg (SBIM), and -1.6±1.7 kg (MBIM). BI methods overestimated FFM before the intervention (before ; DXA : 54.4±4.8 kg, SBIM : 56.5±4.3 kg, MBIM : 55.9±4.5 kg). In nine subjects, FFM measured by SBIM (FFM_SBIM) and MBIM (FFM_MBIM) was similar to FFM measured by DXA(FFM_DXA)(after ; DXA : 54.6±5.4 kg, SBIM : 54.6±3.8 kg, MBIM : 54.6±4.1 kg), although BI methods overestimated the FFM before the intervention (before ; DXA : 54.9±5.1 kg, SBIM : 56.9±3.8 kg, MBIM : 56.3±4.4 kg). The ΔFM_SBIM and ΔFM_MBIM were highly correlated with the ΔFM_DXA(SBIM : r=0.87, MBIM : r=0.88). The ΔFFM_SBIM andΔFFM_MBIM were significantly correlated with the ΔFFM_DXA(SBIM : r=0.54, MBIM : r=0.49). The ΔR₅₀ and ΔRfc were also significantly correlated with the ΔFFM_DXA(R₅₀ : r=-0.63, Rfc : r=-0.48). These results suggest that during a weight-loss intervention, 1) BI methods and DXA provide similar estimates of human body composition change, although they overestimate FFM in obese men, and 2) changes of resistance parameters observed with BI methods may estimate human body composition change more accurately.

A COMPARISON OF SINGLE-AND MULTI-FREQUENCY BIOELECTRICAL IMPEDANCE METHODS TO ASSESS HUMAN BODY COMPOSITION / 体力科学

The purpose of this study was to compare estimates of human body composition determined from single-frequency bioelectrical impedance methods (S-BIM) and multi-frequency bioelectrical impedance methods (M-BIM) . The human body composition was assessed by dual energy X-ray absorptiometry (DEXA), 5 brands of S-BIM, and 2 brands of M-BIM. Forty-five women, aged 26-58 years, served as subjects. The S-BIM and M-BIM fat-free mass (FFM) estimates were highly correlated with the FFM measured by DEXA (r=0.82-0.93) . The standard errors of estimate (SEE) for FFM were approximately 2 kg. With the exception of the MLT-100 (which slightly underestimated FFM), all brands of BIM slightly overestimated FFM. The absolute mean differences between FFMDEXA and each of the 7 BIM estimates ranged from -3.02 kg to 3.46 kg. Although the 7 brands of BIM provided slightly different estimates, the results of this study suggest that 5-BIM and M-BIM are relatively valid in human body composition.

Some Kinds of Developing Techniques and Systems of Electrical Impedance Tomography / 医疗卫生装备

The development of EIT is summarized based on the concept and advantages of the Electrical impedance tomography (EIT) from the following three aspects: multi-frequency electrical impedance tomography (MEEIT), induced current electrical impedance tomography (ICEIT)and magnetic induction tomography (MIT). The advantages of the developing methods are expatiated and compared with the traditional EIT . The future application trend of them is pointed out. EIT is one of the key projects of biomedical engineering today. It is an ideal medical imaging technology with enticing prospect.

A COMPARISON OF SINGLE- AND MULTI-FREQUENCY BIOELECTRICAL IMPEDANCE METHODS TO ASSESS HUMAN BODY COMPOSITION / 体力科学

The purpose of this study was to compare estimates of human body composition determined from single-frequency bioelectrical impedance methods (S-BIM) and multi-frequency bioelectrical impedance methods (M-BIM) . The human body composition was assessed by dual energy X-ray absorptiometry (DEXA), 5 brands of S-BIM, and 2 brands of M-BIM. Forty-five women, aged 26-58 years, served as subjects. The S-BIM and M-BIM fat-free mass (FFM) estimates were highly correlated with the FFM measured by DEXA (r=0.82-0.93) . The standard errors of estimate (SEE) for FFM were approximately 2 kg. With the exception of the MLT-100 (which slightly underestimated FFM), all brands of BIM slightly overestimated FFM. The absolute mean differences between FFMDEXA and each of the 7 BIM estimates ranged from -3.02 kg to 3.46 kg. Although the 7 brands of BIM provided slightly different estimates, the results of this study suggest that 5-BIM and M-BIM are relatively valid in human body composition.

Research on multiple frequency tympanometry on ear system based on ARM / 医疗卫生装备

Objective To study a multiple frequency tympanometry on ear system. Methods Based on the original low frequency and single ingredient SY-IA tympanometry, the study mainly focused on such aspects as multiple frequency probe tone circuit, constant pressure sound control system, micropressor control system and multiple frequency acoustic immitance & phase angle detection circuit. Results Multiple frequency tympanometry on ear system could detect multiple frequency acoustic immitance and phase angle for normal ear, tympanum loosed ear and ossicular chain break ear under different probe tone. Conclusion Experiments show that multiple frequency tympanometry on ear system based on ARM is helpful to the diagnosis of pathological changes which are insensitive to single low frequency tympanometry.