Laser-generated acoustic emission in urological and arterial surgery

Acoustic emission from renal calculi irradiated by a pulsed dye laser was observed in vivo and investigated in vitro. A number of acoustic frequency spectra were recorded from laser exposure of ureteric calculi, calcified arterial wall and bladder tissue. Although differences were observed between spectra, these did not depend on target material. Investigations with model targets suggested that variations in acoustic emission were caused by fluctuations in the strength of the laser plasma, due to changes in the local surface absorption of laser light, and by alterations in the relative orientation of laser fibre, target and transducer. Interaction between lasers and stones is reviewed and discussed.     

一组普通话音位平衡单音节字表的文字编撰

目的编写一组适用于言语识别率测试的音位平衡的单音节测听词表。方法为兼顾测试的可靠性与临床实践中的效率,本课题将简短原则、音位平衡原则、常用字原则、覆盖原则、表间等价性等作为词表编写的主要原则。共设计了30张词表、每张词表包含25个单音节测试项。参照《声学手册》中的汉语音位一维概率分布,计算得到汉语拼音的22个声母(含零声母)、36个韵母、4个声调在30张词表、750个单音节测试项中的分布频次。基于音位平衡原则,通过计算机辅助编程和手动调整,从现代汉语常用字表的一级最常用汉字2500字和常用词表4000词中的单字词表中进行音节编选。结果形成了30张包含声母、韵母、声调在内的音位分配表。选取了489个音节,编撰了30张遵循音位平衡的单音节字表,每张表25字。结论该表文字稿是今后制作汉语音位平衡的单音节语音测试录音材料的基础。     

Word-specific cortical activity as revealed by the mismatch negativity

Neurophysiological brain activity evoked by individual spoken words and pseudowords was recorded and the mismatch negativity (MMN), an automatic index of experience-dependent auditory memory traces, was calculated. Consistent with earlier reported results, the MMN response to word-final syllables was enhanced compared with that elicited by the same syllables placed in a pseudoword context. Here we now demonstrate that the enhancement of the MMN elicited by two individual words showed different scalp topographies. The early word-specific brain activity is consistent with the assumption that the memory traces activated by individual words are carried by large neuronal ensembles that differ in their distributions over the cortex. Current source estimates localized the between-word differences in the right hemisphere and in parieto-occipital left-hemispheric areas. The differential brain responses to individual words appeared as early as ∼100 ms after the recognition points of the words, suggesting that their specific memory traces become active almost immediately after the information in the acoustic input is sufficient for word identification.     

针刺治疗声带小结及计算机声学测定疗效评价

目的:评价针刺开音1号穴治疗声带小结的疗效.方法:将80例患者随机分为针刺组(40例)、中药组(20例)、西药组(20例).针刺组针刺开音1号穴为主;中药组口服金嗓散结丸;西药组采用抗生素、激素类药物雾化吸入.观察3组疗效及治疗前后嗓音学参数.结果:针刺组总有效率为92.5%,优于中药组(85.0%)与西药组(85.0%),差异有非常显著性意义(P<0.01);在改善嗓音学方面,针刺组亦优于其他两组(均P<0.01).结论:针刺开音1号穴治疗声带小结疗效确切.     

Ultrasound Bone Fracture Sensing and Data Communication: Experimental Results in a Pig Limb Sample

Approximately 6.3 million fractures occur each year in the United States alone. Accurately monitoring the progression of fracture healing is essential to be able to advise patients when it is safe to return to normal activity. The most common method used to confirm and monitor fracture healing is the acquisition of multiple radiographic images over the many months required for healing. This imaging method uses large expensive equipment and exposes patients to high levels of ionizing radiation. In the study described here, we tested another technology for monitoring fracture healing that could minimize the need for multiple radiographic images. We tested a piezoelectric transducer fixed to the surface of a bone that uses electromechanical impedance spectroscopy to measure simulated fractures and transmits the measurement data to an acoustic receiver located externally on the skin surface.     

Remote capture of human voice acoustical data by telephone: A methods study

In this pilot study we sought to determine the reliability and validity of collecting speech and voice acoustical data via telephone transmission for possible future use in large clinical trials. Simultaneous recordings of each participant's speech and voice were made at the point of participation, the local recording (LR), and over a telephone line using a dedicated in‐line computerized interactive voice recording system, the remote recording (RR). All voice recordings were made from our laboratory telephone located in Groton, Connecticut to the RR system located in Madison, Wisconsin. All data points were compared on a measure‐by‐measure basis between the LR and RR recordings. The results suggest that both measures of frequency excursion and of speech motor timing are reliably captured over the telephone. Results are discussed in terms of specific acoustic measures that may be useful and accurately measured via telephone transmission, for examining disease severity and pharmacological intervention for use in a large‐scale clinical trial.     

缺血预适应促发心肌毛细血管床功能性开放

目的:探讨反复短暂缺血剌激导致缺血预适应(IP)对心肌毛细血管床功能的影响。方法:复制套扎前降支冠状动脉犬模型。IP组给予缺血5min,灌注5min,反复4次;假手术组不予缺血与灌注剌激,观察40min。分别于实验前、第1次缺血与再灌注及第4次缺血与再灌注末行心肌声学造影,最后对心肌毛细血管进行超微结构观察,并定量分析,做组内及组间比较。结果:第4次缺血较第1次缺血其声学显影最小缺损面积百分比(ADmin%)由32.6%±5.7%降至21.8%±5.2%(P＜0.05),定量分析指标峰值(PI)、曲线下面积(AUC)、峰减半时间(HT)均增高;心肌毛细血管数、管腔内径、内皮细胞厚度及内皮细胞超微结构均无明显差别。结论:反复短暂缺血增加心肌微循环血液灌注但无毛细血管超微结构改变,提示IP促发心肌毛细血管床功能性开放。     

支撑喉镜声带息肉术后嗓音恢复的声学观察

目的 :观察 2 0例声带息肉术后声音恢复的规律以指导患者术后合理用声。方法 :使用嗓音分析方法随访患者术后 2周内的音质变化。结果 :术后当天患者音质最差 ,10d左右始有明显恢复 (P <0 .0 5 ) ,14d时恢复到正常 (P <0 .0 1)。结论 :声带息肉术后患者至少应休声 2周。     

不同元音嗓音分析敏感性的观察

目的 寻找国人较易准确发出，噪音分析敏感性较高的元音音素。方法 比较国际音标／ ／、／a:/、／i:/在噪音分析主要参数指标上的差异并行统计学分析。结果 不同的国际音标在噪音分析主要参数指标上存在一定程度的显著性差异。结论 选择国际音标／i：／作为噪音分析测试音更利于国人准确发音，其敏感性也较高。     

Determination of acoustic power outputs in the microwatt-milliwatt range

A system using an electrobalance for radiation pressure measurements has been developed capable of determining acoustic powers in the microwatt-milliwatt range. Low background “noise” levels are achieved by effective isolation of the balance from building vibrations and shielding the target from convection currents. The standard deviation for a power output of 1 mW is typically less than 1 percent.