招收飞行学员听力检查标准的研究

目的 通过分析招收飞行学员的纯音听阈及文献复习,提出新的招收飞行学员听力检查标准.方法 对2666名青年学生按空军统一听力检查方法进行纯音测听检查,测听频率为250～8000 Hz,分析其80%、90%、95%、99%百分位值.查阅外军飞行员选拔听力检查标准,与我军听力检查标准进行对比.结果 在第1次检查的2584耳中,80%的学生高频听力在正常范围.6000 Hz听力损失的程度和比率较高,90%分位值为30 dB,95%分位值为35 dB,99%分位值为55 dB;其次是4000 Hz和8000 Hz,95%分位值为25 dB,99%分位值为40 dB.在第2次检查的2748耳中,也有80%的学生高频听力在正常范围.6000 Hz和8000 Hz处听力损失的程度和比率较高,95%分位值为30 dB,99%分位值是45 dB;其次是4000 Hz,99%分位值是40 dB.结论 建议我军招收飞行学员听力检查标准,500～2000 Hz小于25 dB,3000 Hz、4000 Hz和6000 Hz平均听阈不超过40 dB;将低频250 Hz和高频8000 Hz两个频率去除. Abstract： Objective To raise new hearing examination standard for the selection of flying cadets by analyzing the pure tone threshold of audibility and reviewing related literatures.Methods Two thousand six hundred and sixty-six flying cadet candidates were tested by Audiomer.Testing frequencies were from 250 to 8000 Hz.Percentiles of 80%, 90%, 95% and 99% were analyzed.In literature review foreign military hearing examination standards were compared with China's.Results Hearing threshold of 80% candidates was normal in the first test of 2584 ears.Obvious audibility loss and high ratio were found at 6000 Hz and were respectively 30 dB, 35 dB and 55 dB corresponding to the percentiles of 90%, 95% and 99%.2748 ears were examined in second test and 80% of them showed normal value in high frequency range.6000 Hz and 8000 Hz were the frequencies where obvious audibility loss and high ratio of amblyacusia appeared, that was 30 dB loss for 95%percentile and 35 dB for 99 % respectively.Then 40 dB loss for 99 % percentile was got at 4000 Hz.Conclusions It is suggested that hearing standard for the selection of flying cadet should be revised and the tests at 250 Hz and 8000 Hz could be cancelled.New hearing exam standard could be suggested as less than 25 dB loss for 500-2000 Hz tests and the average hearing threshold couldn't exceed 40 dB corresponding to the tests at 3000 Hz, 4000 Hz and 6000 Hz.     

Effect of hearing aids on static balance function in elderly with hearing loss

While a few studies have investigated the relationship between hearing acuity and postural control, little is known about the effect of hearing aids on postural stability in elderly with hearing loss. The aim was to compare static balance function between elderly with hearing loss who used hearing aids and those who did not use. The subjects asked to stand with (A) open eyes on rigid surface (force platform), (B) closed eyes on rigid surface, (C) open eyes on a foam pad, and (D) closed eyes on a foam pad. Subjects in the aided group (n = 22) were tested with their hearing aids turned on and hearing aids turned off in each experimental condition. Subjects in the unaided group (n = 25) were tested under the same experimental conditions as the aided group. Indicators for postural stability were center of pressure (COP) parameters including; mean velocity, standard deviation (SD) velocity in anteroposterior (AP) and mediolateral (ML) directions, and sway area (95% confidence ellipse). The results showed that within open eyes–foam surface condition, there was greater SD velocity in the off-aided than the on-aided and the unaided than the on-aided (p < 0.0001 for SD velocity in AP and ML). Also, no significant differences were found between the off-aided and unaided group (p = 0.56 and p = 0.77 for SD velocity in AP and ML, respectively). Hearing aids improve static balance function by reducing the SD velocity. Clinical implications may include improving hearing inputs in order to increase postural stability in older adults with hearing loss.     

Assessment of blood lactate: practical evaluation of the Biosen 5030 lactate analyzer

PURPOSE: The aim of this study was to assess the validity and reliability of the Biosen 5030 lactate analyzer compared with a YSI 2300 lactate analyzer and a Kodak Ektachem DTII in a practical laboratory study context. METHODS: To assess validity, 144 triplicate capillarized blood samples, across a range of values, were analyzed using the three analyzers. To assess reliability a further 665 samples were repeat analyzed. Temporal stability was determined by the reanalysis of resting and maximal exercise blood samples, after a period of storage ranging from 7 to 20 h, at room temperature. To measure inter- and intra-investigator reliability, 20 resting samples were taken from three different subjects by different investigators and a coefficient of variation was determined. RESULTS: There were strong relationships between the Biosen, the YSI (r2 = 0.97), and the Kodak Ektachem (r2 = 0.91). An analysis of Biosen compared with YSI revealed a positive bias of 0.37 mmol x L(-1) (95% limits of agreement, -0.85 to 1.59 mmol x L(-1)). The test-retest reliability correlation was significant (r2 = 0.99, P < 0.05), but a paired t-test revealed a small (0.03 mmol x L(-1), P < 0.05) significant difference. The coefficient of variation from the three investigators across the 20 samples ranged from 1.3 to 3%. Blood lactate concentration in resting blood samples did significantly increase in value (0.2 mmol x L(-1), P < 0.05) after 7-h exposure to the air, whereas there was no change in maximal exercise blood lactate values after 20-h exposure to the air. CONCLUSIONS: In a practical context, the Biosen 5030 lactate analyzer was comparable to the other analyzers giving fast reliable measures of blood lactate concentrations over the full range of values, which remained stable over extended periods at room temperature.     

Assessment of personal qualities in selection of medical radiation science students

It is increasingly acknowledged that, in addition to prior academic achievement, there is a need to seek evidence for the abilities and personal qualities of applicants to health professional programs at a university. The aim of this study was to determine the specific abilities and personal qualities required for excellence in practice in the relevant professional domains of medical radiation science (MRS). METHODS: A focus group, consisting of MRS academic staff, developed a questionnaire. The questionnaire was sent to senior MRS practitioners throughout Australia and 213 were returned for analysis. Respondents were asked to rate 40 specific abilities and qualities (referred to as "elements") on a 5-point scale. RESULTS: Two hundred thirteen completed questionnaires were returned, a 53% response rate. One hundred twelve respondents (52%) indicated they currently worked in diagnostic radiography (DR), 57 (27%) worked in radiation therapy (RT), and 44 (21%) worked in nuclear medicine (NM). The duration (mean +/- SD) of the respondents' professional practice in MRS was 14.5 +/- 10 y, with durations ranging from 1 to 43 y. Raw scores and mean scores were examined for any influence of the variable "Number of Years in Practice." DISCUSSION: No major differences were found between the ratings provided by the practitioners from the 3 different MRS professional domains of NM, RT, and DR. Factor analysis indicated the existence of 3 orthogonal factors in the questionnaire data: (a) treat others professionally and ethically, (b) engage with and be open to others, and (c) problem-solving ability. Qualitative analysis of the respondents' comments provided similar themes: (a) the need for professional competence (knowledge and abilities), (b) ethical behavior, (c) the need for a technology and a people orientation, and (d) MRS should be the first choice of MRS students and not a second choice to other professional degrees. CONCLUSION: Senior medical radiation scientists identified professionalism, ethical behavior, engagement with and openness to others, intrinsic specific motivation, and an orientation to people and technology as nonacademic qualities required for excellence in the practice of the professions embraced by MRS.     

Assessment of cardiac function by CMR

Cardiovascular magnetic resonance (CMR) has emerged as a valuable tool for the non-invasive morphological and functional assessment of the heart. By means of a variety of pulse sequences, accurate estimations of ventricular mass, volumes, ejection fraction and flow volume can be readily performed. When carefully prescribed, CMR sequences provide values on these parameters that can be considered as referential for both the right and left ventricle. This is due to the anatomical approach of the CMR method that, in contrast with other imaging techniques, is based on direct measurements rather than on indirect geometrical assumptions.     

Assessment of the left ventricular function with the Nuclear Stethoscope

The evaluation of the left ventricular function with the Nuclear Stethoscope was performed on 27 patients with heart diseases. The reproducibility of the measurements was good. Repetitions of EF, ER and EDV estimations yielded errors of 2.63%, 1.45% and 0.31%, respectively. The comparison with the results of camera ventriculography showed a good agreement of EF, contraction velocity parameters and relaxation velocity parameters, with a cor. coeff. of greater or equal to 0.750. An especially high correlation was found between the NS EF and NS ER (r=0.968). It was concluded that the Nuclear Stethoscope provides a reliable evaluation of left ventricular function.Fellow of the Alexander von Humboldt Foundation