双道高精度数控医用信号仪的研制

目的:研制出一种以单片机和高性能芯片为核心研制的医用信号仪。方法:主要利用单片机控制两片高精度数控频率和位相的IC(AD9833)和D/A转换IC(AD558)等,并利用LCD显示信号的相关参数。结果:该仪器可输出双道高精度频率和位相的正弦、三角、方波信号及各种生理信号。可用于人耳频率特性和人体阻抗特性的研究和教学;利用同时输出的两道位相差可数控的正弦信号,可方便地演示医学物理等教学中两简谐振动在不同频率、不同相位差、不同方向等情况下的合成,如拍频、李萨如图形等。结论:该智能仪器可广泛用于实验教学、临床测试和医疗仪器维修。     

听觉刺激器的研制

作者介绍一种用微机听觉诱发电位刺激器。该刺激器可以产生“喀呖”声，具有十二档刺激频率，四档刺激脉冲宽度，刺激强度最大１３２分贝，并具白噪声屏蔽。     

基于ARM7的新型开放式多功能医用信号仪的研制

目的现有的常用信号发生器或生理信号发生器不能同时输出常用信号和模拟生理信号,本文提出一种新型开放式多功能医用信号仪,用于检测各种生理信号,听取不同频率、不同信号的声音及输出常用信号等。方法该仪器以STM32F103RF和高性能集成芯片MAX038为核心。此医用信号仪包括硬件和软件两部分,其中硬件含有ARM7单片机控制单元、按钮组输入单元、数据存储单元等12个单元,软件用C语言编写,并采用keil C进行编译。结果该仪器不仅能输出常用的正弦、方波、三角波、锯齿、矩形信号,还能输出医学中常用的多种生理信号如心电、脉搏波等,且信号波形频率、幅度、类型、波形均采用直观的LCD液晶显示。此外,该仪器具有一个高驱动能力的接口,可直接驱动耳机等,以方便对人耳频率特性和人体阻抗特性的研究和教学。同时,为了便于使用一般示波器能观察各种生理信号,对同一种生理信号可输出不同的频率。结论本仪器使用方便,可广泛应用于科研、教学、测试和仪器维修等。     

滤波器概念与听觉外周的频率分析

本文从生理学实验结果讨论了听觉外周特别是耳蜗在频率分析中的作用，通过对耳蜗的某些性质与线性带通滤波器的比较，指出了我们在采用工程语言对听觉系统进行描述时，以及在用工程的方法提高人的听力时所必需注意的某些问题，尤其是听觉外周所表现的非线性性质。     

多频稳态诱发电位对感音神经性聋儿童的听力评估

目的 探讨多频稳态听觉诱发电位对感音神经性聋儿童的听力评估的临床意义.方法 采用美国GSI-Audera测试系统,应用单频刺激的方式,对感音神经性聋45例(90耳)行多频稳态听觉诱发电位(ASSR)检测和纯音听阈测试(PTA),比较两者测试阈值,分析不同频率处听力阈值分布情况及其相关性.结果 不同频率ASSR阈值均数与纯音听力均数差值为2～7.5dBHL;各频率ASSR测试值与相应频率纯音听阈间差异均有统计学意义(t检验P<0.05),各频率ASSR测试值与相应频率纯音听力均有相关性(P<0.05),且随着测试频率的递增,两者的相关系数有增高的趋势.结论 多频稳态听觉诱发电位可对感音神经性聋儿童的听力进行评估,为低龄儿童及难以检测行为听力的患儿验配助听器提供依据.     

以解剖结构为基础讲解噪声对听觉的损伤

卫生学认为，当声响干扰到人的睡眠休息、交谈思考，给人以烦恼感受，或造成听觉危害时，统称为噪声。而噪声对机体损伤的靶器官就是听觉器官，因此在课程标准中将噪声对听觉的影响列为了讲解的重点，也是学生理解的难点。教研室通过集体备课，高年资、经验丰富的教员进行指导后，在教学实践中进行了相应改革。在传统的教学之外，系统地引入听觉系统的解剖学结构，采用多媒体课件，融入相关的视频和声频资料，加以板书作图的方式，来对学生进行讲解，取得了很好的课堂教学效果。本文就如何以解剖学结构为基础来讲解噪声对听觉的损伤，初步谈一下自己的教学体会和认识。     

电触听代偿仪的研制

本文主要介绍电触听代偿仪的设计和研制。系统采用８０９８单片机及相关的模拟和数字接口电路实现了声音信号实时采集、处理及触觉编码输出等功能。初步实验表明：通过使用本系统，受试者在经过训练后，屏蔽听觉能分辨出环境中的不同警示声如门铃声、汽车喇叭声等，能感受到语音的节律，能帮助其判断声源的方向。     

听觉脑干电反应可有效预测听力损失患儿的行为听阈

目的探讨幼儿听力损失程度对听觉脑干电反应(ABR)预测行为听阈(BT)的影响。方法选取2012年1月至2016年1月在延安大学附属医院接受听觉脑干电反应和行为听阈测试的179例不同听力损失程度的患儿(共311只耳)作为研究对象,分别对179例患儿进行听觉脑干电反应测试和行为听阈测试,分析听觉脑干电反应与行为听阈相关性,分析ABR阈值与行为阈差值与ABR阈值的影响因素及校正因子以及相关线性回归方程。结果不同频率刺激下,ABR阈值与行为听阈均呈正相关(P0.05);不同刺激频率下ABR阈值均可预测行为听阈;ABR阈值预测行为阈差值的误差与听力损失程度相关(P0.05),通过校正可以减少预测误差。结论听觉脑干电反应可以有效预测听力损失患儿的行为听阈,听力损失程度影响听觉脑干电反应与行为听阈间的差异,恒定的修正系数有利于听觉脑干电反应预测行为听阈的精确性。     

基于80c196单片机的实时24小时动ECG记录分析仪的研究

本文介绍了一种２４小时双通道固态记录与实时分析于一体的便携式心电记录分析仪的设计。仪器以８０ｃ１９６单片机为核心，配以大规模单片机接口电路芯片ＰＳＤ４０３使得整机体积小且功耗低，该仪器的显著特点是无须连接ＰＣ机进行后处理即可独立联接打印机输出动态心电分析监护报告，报警事件报告和心率变异分析报告。借助于ＭＩＴ心电数据库，采用数模转换后的输出信号作为模拟心电波对样机进行检验，其结果表明该仪器硬件合理实用，分析算法的实时性和准确性都能够满足要求。经临床２２例验证，各设计指标均已达到要求     

基于变频原理的超声波治疗仪设计

介绍一种新颖变频超声波治疗仪的设计方法.针对常用超声治疗仪存在的问题,提出了变频超声的学术思想,用不同频率的超声信号产生不同刺激深度的信号.采用MSP430系列超低功耗单片机作为控制芯片,压控振荡器作为产生可变频率的核心模块,配有显示模块、键控模块等.整机结构新颖,体积小,智能化程度高,操作方便,使用安全可靠.     

A training aid for audiometry practice

An instrument is described that enables the student of audiometry to acquire expertise in routine pure-tone threshold testing without involving a human subject. The hearing loss of a hearing-impaired subject is simulated by electrical circuits, and the threshold response to operation of the ‘audiometer’ interrupter key is given by light signals. The effect of adjusting controls labelled ‘frequency’, ‘signal’ and ‘mask’ can be clearly demonstrated. Both the representation of audiometer controls and the simulated patient are contained in the one instrument.     

Growth factor and receptor malfunctions associated with human genetic deafness

A variety of different signaling pathways are necessary for development and maintenance of the human auditory system. Normal hearing allows for the detection of soft sounds within the frequency range of 20 to 20 000 Hz, but more importantly to perceive the human voice frequency band of 250 to 6000 Hz. Loss of hearing is common, and is a clinically heterogeneous disorder that can be caused by environmental factors such as exposure to loud noise, infections and ototoxic drugs. In addition, variants of hundreds of genes have been reported to disrupt processes required for hearing. Noncoding regulatory variants and variants of additional genes necessary for hearing remain to be discovered as many individuals with inherited deafness are without a genetic diagnosis, despite the advent of whole exome sequencing. Here, we discuss in detail some of these deafness-causing variants of genes encoding a ligand or its receptor. Spotlighted in this review are three growth factor-receptor-pairs EDN3/EDNRB, HGF/MET and JAG/NOTCH, which individually are necessary for normal hearing. We also offer our perspective on unanswered questions, future challenges and potential opportunities for treatments emerging from molecular genetic and mechanistic studies of deafness due to these causes.     

Two novel missense mutations in the TECTA gene in Korean families with autosomal dominant nonsyndromic hearing loss

The TECTA gene, which encodes alpha-tectorin, is known as a causative gene for DFNA8/DFNA12, and DFNB21 hearing loss in humans. In the present study, mutation analysis of the TECTA gene was performed in 62 Korean patients with hereditary hearing loss. Two novel nucleotide substitutions, p.V317E and p.T1866M, were identified for the first time in the Korean population. These mutations result in the substitution of amino acids in the zonadhesin (ZA) and the zona pellucida (ZP) domains, and show a genotype-phenotype correlation, which is a characteristic of TECTA-related mutations in autosomal dominant nonsyndromic hearing loss. Both mutations are located in highly conserved regions of alpha-tectorin and were not found in 120 unrelated control subjects with normal hearing. Based on this evidence, it is likely that both mutations are the pathogenic ones causing the hearing loss. This study provides useful information for the functional study of hereditary hearing loss caused by tectorial membrane defects.     

Newborn genetic screening for hearing impairment: a population-based longitudinal study

PurposeThe feasibility of genetic screening for deafness-causing mutations in newborns has been reported in several studies. The aim of this study was to investigate the long-term results in those who screened positive for deafness mutations; these results are crucial to determine the cost-effectiveness to justify population-wide genetic screening.MethodsWe performed simultaneous hearing screening and genetic screening targeting four common deafness mutations (p.V37I and c.235delC of GJB2, c.919-2A>G of SLC26A4, and the mitochondrial m.1555A>G) in 5173 newborns at a tertiary hospital between 2009 and 2015. Serial audiometric results up to 6 years old were then analyzed in children with conclusive genotypes.ResultsNewborn genetic screening identified 82 (1.6%) babies with conclusive genotypes, comprising 62 (1.2%) with GJB2 p.V37I/p.V37I, 16 (0.3%) with GJB2 p.V37I/c.235delC, and 4 (0.1%) with m.1555A>G. Of these, 46 (56.1%) passed hearing screening at birth. Long-term follow-up demonstrated progressive hearing loss in children with the GJB2 p.V37I/p.V37I and p.V37I/c.235delC genotypes; this hearing loss deteriorated by approximately 1 decibel hearing level (dBHL) per year.ConclusionsWe delineated the longitudinal auditory features of the highly prevalent GJB2 p.V37I mutation on a general population basis and confirmed the utility of newborn genetic screening in identifying infants with late-onset or progressive hearing impairment undetectable by newborn hearing screening.     

高压对耳蜗的影响

目的研究高压环境对人耳蜗的影响,弥补试验手段不足导致的耳蜗在高压环境下听力行为特征研究的缺失,为今后对耳蜗进行针对性研究提供新的思路。方法基于健康人耳蜗CT扫描图像,结合自编程序,利用PATRAN软件建立三维螺旋耳蜗有限元模型。应用NASTRAN软件进行流固耦合频率响应分析和瞬态响应分析,通过数值模拟方法研究高压对耳蜗的影响。结果基底膜12 mm处与镫骨底板中心(卵圆窗的中心)处位移比值模拟结果与已报道的试验结果相吻合,验证了所建模型的正确性。高压环境下,耳蜗中基底膜特征频率点的幅值随着压强的增大而不断减小。结论高压环境最终导致人耳听力的降低。研究结果为临床上研制防治高压的缓冲装置提供理论支撑。     

Analysis of the factors influencing the response of the skin to audio signals

Skin-hearing aid is a new type of electronic product, which can improve hearing for deaf patients. It is different from audiphones and cochlear implant. The instrument makes use of the effect of the skin response to audio signals. The working process of the instrument is as following. Firstly, the sound signal is converted to audio signal by microphone, then through the power amplifier and booster. Then the signal is transmitted to the brain via skin by electrodes. And finally the hearing is formed. As skin-hearing aid transmits signals through the skin by the electrodes, the intensity of the skin resistance becomes the main factor influencing the response of the skin to audio signal. Skin resistance depends mainly upon the stratum corneum. This article aims to discuss the factors affecting the skin resistance, such as the thickness of the stratum corneum, hydration level of stratum corneum, the relation of audio frequency and skin resistance, and the skin resistance of acupuncture points.     

Tuning and sensitivity of the human vestibular system to low-frequency vibration

Mechanoreceptive hair-cells of the vertebrate inner ear have a remarkable sensitivity to displacement, whether excited by sound, whole-body acceleration or substrate-borne vibration. In response to seismic or substrate-borne vibration, thresholds for vestibular afferent fibre activation have been reported in anamniotes (fish and frogs) in the range -120 to -90dB re 1g. In this article, we demonstrate for the first time that the human vestibular system is also extremely sensitive to low-frequency and infrasound vibrations by making use of a new technique for measuring vestibular activation, via the vestibulo-ocular reflex (VOR). We found a highly tuned response to whole-head vibration in the transmastoid plane with a best frequency of about 100Hz. At the best frequency we obtained VOR responses at intensities of less than -70dB re 1g, which was 15dB lower than the threshold of hearing for bone-conducted sound in humans at this frequency. Given the likely synaptic attenuation of the VOR pathway, human receptor sensitivity is probably an order of magnitude lower, thus approaching the seismic sensitivity of the frog ear. These results extend our knowledge of vibration-sensitivity of vestibular afferents but also are remarkable as they indicate that the seismic sensitivity of the human vestibular system exceeds that of the cochlea for low-frequencies.     

High-Resolution fMRI of Auditory Cortical Map Changes in Unilateral Hearing Loss and Tinnitus

Animal models of hearing loss and tinnitus observe pathological neural activity in the tonotopic frequency maps of the primary auditory cortex. Here, we applied ultra high-field fMRI at 7 T to test whether human patients with unilateral hearing loss and tinnitus also show altered functional activity in the primary auditory cortex. The high spatial resolution afforded by 7 T imaging allowed tonotopic mapping of primary auditory cortex on an individual subject basis. Eleven patients with unilateral hearing loss and tinnitus were compared to normal-hearing controls. Patients showed an over-representation and hyperactivity in a region of the cortical map corresponding to low frequencies sounds, irrespective of the hearing loss and tinnitus range, which in most cases affected higher frequencies. This finding of hyperactivity in low frequency map regions, irrespective of hearing loss range, is consistent with some previous studies in animal models and corroborates a previous study of human tinnitus. Thus these findings contribute to accumulating evidence that gross cortical tonotopic map reorganization is not a causal factor of tinnitus.