电子耳蜗的小波过零刺激方案及其DSP实现

目的：介绍小波过零刺激（Wavelet Zero—cross Stimulation，WZS）算法，并利用该算法设计实现人工电子耳蜗系统。方法：基于DSP芯片，采用ICETEK—VC5416语音开发板模拟小波过零刺激语音编码策略，同时进行人工电子耳蜗系统的硬件设计，并将计算机模拟的结果和CIS方案对比。结果：经过小波过零刺激算法处理的8个通道的语音信号进行合成，然后经扬声器播出，可听见较清晰的声音。结论：对小波过零刺激方案于语音信号小波变换域的过零点处合成刺激脉冲，其保留了语音信号的时域相关性和相干性，能够反映人的耳蜗对语音信号的时间编码特性。     

基于示波法和柯氏音法的双踪电子血压测量系统

目的：为了深入研究示波法血压测量技术，获取基于个体特征的血压测量方法，我们设计了基于示波法和电子柯氏音法的血压测量平台，同步采集袖带放气过程中的振荡波和电子柯氏音。方法：使用固体振动传感器获取声音振动信号，使用压力传感器经过信号调理后获得袖带压力和振荡波信号，使用14bits数据采集卡USB6009同步采集上述信号。结果：对压力传感电路以及电子柯氏音电路经过定标后，开展了初步的预试验，试验结果表明该血压测量平台能够有效的获取袖带充放气过程的振动波以及电子柯氏音。     

基于ADuC848的氦氧循环通气装置的研制

从治疗呼吸衰竭的途径入手，提出了使用氦气和氧气混合气体的通气方式，介绍了基于ADuC848开发的氯氧循环通气装置。通过测量气路中压力、氧浓度、温度等信号，对氧气、氯气的输出实现PID控制，重点对通气装置中电子测控单元进行了详细分析。     

基于电子听诊器的心肺音智能诊断技术综述

心肺疾病是威胁人类健康的主要疾病，致死率居我国慢性病死因的前3位。对于心肺疾病的前期诊断，听诊器听诊是最便捷、最重要的手段。随着医疗设备智能化技术的发展，电子听诊器取代传统听诊器的趋势越来越明显，临床医师可通过对电子听诊器采集的听诊信号进行分析，进行心肺疾病的诊断。该研究介绍了基于电子听诊器的心肺音智能诊断中存在的技术问题，从心肺音数据库、前端声信号处理技术及人工智能诊断技术3方面进行综述，并对未来心肺音智能诊断技术的研究方向进行了展望。     

自制西门子MEVATRON直线加速器INJECTOR中电源模块

进口加速器上所用的元件，国内往往买不到现成的产品。向外国公司购买，价格十分昂贵，周期又长。这样既降低了机器的利用率，又影响了病人的治疗。　　本文介绍自制西门子ＭＥＶＡＴＲＯＮ直线加速器中ＩＮＪＥＣＴＯＲ中的±１５ＶＤＣ，１００ｍＡ的电源模块的实例。１　要求１．１　ＩＮＪＥＣＴＯＲ有两个功能，一是控制注入到加速波导管的电子总数，二是控制注入到加速波导管的电子速度。电子总数的多少通过控制到达电子枪栅极的正的脉冲信号频率来实现，栅极脉冲频率越高，发射的电子越多。这些电子再由电子枪的高压控制段加速后以１…     

可降血压的植入性电子芯片

日前，德国弗赖堡大学科研人员发明了一种降血压的植入性电子芯片，高血压患者植入该电子芯片后，可以不用长期服用降压药物。该电子芯片共有24个电极。动物实验时，在实验鼠颈部的迷走神经系统中植入该电子芯片后，芯片对实验鼠大脑向心脏发出的血压调控信号进行了传输反馈控制，其通过24个电极的开闭，选择性地刺激神经纤维，从而调控血压。     

跑道式医用电子回旋加速器的原理

带电粒子加速器是核物理实验研究的重要工具，在恶性肿瘤的放射治疗中占有重要的地位。着重介绍了电子回旋加速器原理，重点介绍了跑道式电子回旋加速器的工作原理，并对电子回旋加速器和电子直线加速器的特点进行了比较。     

一种伺服控制扇形扫描技术

本文介绍一种由闭环电路电子伺服机构控制的超声束扫描技术,换能器在其永久磁铁受到可控交变磁场影响时摆动。换能器角度位置信号通过改变位置敏感线圈电感量取得。     

关于电子病历系统的探讨

介绍了电子病历应具有的基本功能，及使用电子病历要达到哪些目的，提出在推广电子病历过程中存在的一些问题。     

电子病历的发展现状和发展趋势

介绍了电子病历的定义和应用意义，阐述了实现电子病历的关键技术和其所须遵循的协议标准，回顾了国内外电子病历的发展状况，指出了国内电子病历发展面临的问题，并结合国内外学者的科研成果，提出了未来电子病历智能化、标准和集成化、区域共享化的发展趋势。     

基于蓝牙的听诊器综述

听诊器是最常见的医疗器械之一,随着近年来蓝牙技术的发展,一类新型的听诊器——蓝牙听诊器也随之诞生j本文介绍了国内外基于蓝牙的听诊器的发展情况,并指出了它们的优点及不足。     

基于蓝牙的听诊器综述

听诊器是最常见的医疗器械之一,随着近年来蓝牙技术的发展,一类新型的听诊器——蓝牙听诊器也随之诞生。本文介绍了国内外基于蓝牙的听诊器的发展情况,并指出了它们的优点及不足。     

Can we measure the ankle-brachial index using only a stethoscope? A pilot study

Background. Ankle-brachial index (ABI) is an excellent methodfor the diagnosis of peripheral arterial disease (PAD) whenit is performed with Doppler. However, this device is not alwaysavailable for primary care physicians. The ABI measured withstethoscope is an easy alternative approach, but have not beenproved to be useful. Objective. To assess the accuracy of the ABI measured usinga stethoscope comparatively to that of the current eligiblemethod for the diagnosis of PAD, the Doppler ABI, and describethe characteristics of this new approach. Methods. We conducted a diagnostic study of ABI measured witha stethoscope and a Doppler probe and compared the results.Eighty-eight patients were accessed by both methods. Results. Mean stethoscope ABI, 1.01 ± 0.15, and meanDoppler ABI, 1.03 ± 0.20, (P = 0.047) displayed a goodcorrelation. Measurements of stethoscope ABI diagnostic accuracyin recognizing a Doppler ABI are described. The comparison ofthis data with the current gold standard method results gavea sensitivity of 71.4% [95% confidence interval (CI), 41.9–91.6]and specificity of 91.0% (95% CI, 81.5–96.6), with predictivepositive value of 62.5% (95% CI, 38.6–81.5) and negativepredictive value of 93.8% (95% CI, 85.2–97.6). The studyaccuracy was 87.7%. The area under the ROC curve was 0.895 (95%CI, 0.804–0.986, P < 0.0001). Conclusions. According to our study, the stethoscope ABI isa useful method to detect PAD and it may be suitable for itsscreening in the primary care setting. Keywords. Ankle-brachial index, peripheral arterial disease, stethoscope.     

Quality of Korotkoff sounds: bell vs diaphragm, cubital fossa vs brachial artery

Comparison of clarity of Korotkoff sounds was made between those heard with the bell or diaphragm of the stethoscope and between those heard over the cubital fossa or more proximally and medially over the maximal brachial artery pulse--during indirect sphygmomanometry. Multiple measurements were made by two trained technicians on 48 supine adults. The measurements were balanced as to stethoscope-head/arm-placement combinations, stethoscope used, control of the pressure bulb, and use of right or left arm. The Korotkoff sounds were heard better with the bell of the stethoscope placed over the brachial artery pulse (BB) than with the diaphragm placed over the cubital fossa (DC). The former combination (BB) gave significantly higher blood pressure estimates for systolic blood pressure and fourth phase diastolic blood pressure than the latter combination (DC).     

Contamination of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci.

OJECTIVE: To measure directly the rate of contamination, during routine patient examination, of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci (VRE). SETTING: A large, academic, tertiary-care hospital. PATIENTS: Between January 1997 and December 1998, 49 patients colonized or infected with VRE were entered in the study. DESIGN: After routine examination, the examiner's glove fingertips, gown (the umbilical region and the cuffs), and stethoscope diaphragm were pressed onto Columbia colistin-nalidixic acid (CNA) agar plates with 5% sheep blood plus vancomycin 6 pg/mL. The stethoscope diaphragm was sampled again after cleaning with a 70% isopropanol wipe. RESULTS: VRE were isolated from at least 1 examiner site (gloves, gowns, or stethoscope) in 33 (67%) of 49 cases. Gloves were contaminated in 63%, gowns in 37%, and stethoscopes in 31%. All three items were positive for VRE in 24%. One case each had stethoscope and gown contamination without glove contamination. Only 1 (2%) of 49 stethoscopes was positive after wiping with an alcohol swab. Contamination at any site was more likely when the patient had a colostomy or ileostomy. Patients identified by rectal-swab culture alone were as likely to contaminate their examiners as were those identified by clinical specimens. CONCLUSIONS: Our study revealed a high rate of examiner contamination with VRE. The similar risk of contamination identified by surveillance and clinical cases reinforces concerns that patients not known to be colonized with VRE could serve as sources for dissemination. Wiping with alcohol is effective in decontaminating stethoscopes.     

Bacterial contamination of fabric stethoscope covers: the velveteen rabbit of health care?

To determine if fabric stethoscope covers pose an infection control problem, we studied how they are cared for by our healthcare workers and performed microbiological investigations on 22 covers collected over a 3-week period. Our study suggests that fabric stethoscope covers represent a potential infection control problem because they are used for prolonged periods, are infrequently laundered, and are contaminated with bacteria.     

Bacterial contamination of hospital physicians' stethoscopes.

Because stethoscopes might be potential vectors of nosocomial infections, this study, conducted in a 450-bed general hospital, was devised to evaluate the bacterial contamination of stethoscopes; bacterial survival on stethoscope membranes; the kinetics of the bacterial load on stethoscope membranes during clinical use; and the efficacy of 70% alcohol or liquid soap for membrane disinfection. Among the 355 stethoscopes tested, 234 carried > or =2 different bacterial species; 31 carried potentially pathogenic bacteria. Although some bacteria deposited onto membranes could survive 6 to 18 hours, none survived after disinfection.     

The stethoscope in the Emergency Department: a vector of infection?

The purposes of this study were to determine whether microorganisms can be isolated from the membranes of stethoscopes used by clinicians and nurses, and to analyse whether or not the degree of bacterial colonization could be reduced with different cleaning methods. We designed a transversal before-after study in which 122 stethoscopes were examined. Coagulase negative staphylococci (which are also potentially pathogenic microorganisms) were isolated together with 13 other potentially pathogenic microorganisms, including S. aureus, Acinetobacter sp. and Enterobacter agglomerans. The most effective antiseptic was propyl alcohol. Analysis of the cleaning habits of the Emergency Department (ED) staff, showed that 45% cleaned the stethoscope annually or never. The isolation of potentially pathogenic microorganisms suggests that the stethoscope must be considered as a potential vector of infection not only in the ED but also in other hospital wards and out-patient clinics.     

医院内获得性感染调查及预防措施

目的了解引起重症监护室医院获得性感染的因素,采取预防措施,减少医院获得性感染的发生。方法对重症监护室40例次医院获得性肺炎的资料进行前瞻性研究,并通过环境卫生学监测,探讨其发生原因和传播途径。结果引起医院获得性肺炎的病原体主要为革兰氏阴性杆菌(77%),其中又以铜绿假单胞菌为主(35.7%)。环境卫生学监测从听诊器上检出多重耐药的铜绿假单胞菌,另外医务人员的手、集水瓶、手电筒和床头柜细菌超标。结论抗生素的广泛使用是以铜绿假单胞菌感染为主的医院获得性肺炎的主要原因;听诊器的污染是导致多名患者交叉感染多重耐药的铜绿假单胞菌的重要原因,医务人员的手是其传播途径。     

A remote auscultation tool for advanced home health-care

We have developed an Internet-based tool for remote realtime auscultation. The device was based on a commercially available electronic stethoscope and a PC which digitized and transmitted the signals. A voice and video channel were also available. The remote auscultation tool was evaluated between two sites in Sweden separated by a distance of 500 km. A doctor at one of the sites performed cardiac and pulmonary auscultations on patients located at the other site. Four test patients were assisted by a nurse operating the electronic stethoscope. The auscultation sessions were performed with and without video support to assess the importance of visual contact between doctor and patient. Twenty sessions were conducted (excluding technical testing to solve problems with the equipment). Audio quality was sufficient, as judged subjectively by the doctors concerned. Video support improved the doctor s confidence that the stethoscope was being operated properly and greatly simplified the interaction. Moreover, it improved all participants subjective impression of the virtual meeting. Our work demonstrates the feasibility of performing remote auscultation sessions over the Internet.