软组织生物力学特性的测量:仪器设计

软组织的生物力学特性是诊断软组织病变的重要依据。本研究设计了一种新的仪器来在线测量软组织的生物力学特性。该仪器通过一个特别设计的集成传感器，获取软组织的应力和应变信息。集成传感器由超声传感器和应变片组成的压力传感器通过串连方式连接而成；对超声回波信号与发射信号进行互相关运算，获取软组织的应变信号，这个过程用FPGA来实现。基于软组织的生物力学模型和所获得的软组织的应力应变信号，提取软组织的特性参数。该仪器对超声回波信号和压力信号数据的采集，处理和显示通过DSP控制来实现；该仪器能测量软组织的不同层的厚度，便于运动检测和健身监测之用。     

基于连续小波变换的心电信号特征提取及其仪器实现

介绍了一种用于心电信号的记录和识别的虚拟式测量和分析仪器系统，目的是要构建一种基于PC的虚拟仪器．能够实现十二导联心电信号的同步记录、同步整体观察及测量12导联同一心动周期的波形，从而提高心电参数测量的准确性。同时，由于Mexican hat小波特有的时域特性，对QRS波群具有很好的定位特性和分析精度，因此在本仪器中利用连续小波变换，选用Mexicanhat作为小波基，对心电信号中的特征信息进行精确检测，并给出准确的心电信号特征描述参数。对临床实测心电信号的分析表明，即使在有严重噪声干扰的情况下，本方法也很容易实现对心电信号特征信息的精确描述，并且具有很高的实时性，从而在本仪器中获得了实际和有效的应用。     

运用数字体相关方法追踪呼吸过程中肺部肿瘤和胸腔的运动

目的 研究数字体相关（digital volume correlation,DVC）方法测量肺部肿瘤和胸腔随患者呼吸运动的变形及位移情况的可行性。方法 利用DVC跟踪胸腔内组织三维运动的算法,通过四维CT成像技术拍摄肺癌患者一个完整的呼吸过程。以吸气开始为初始状态,确定肿瘤和胸腔位置,运用DVC软件,分析初始状态下肺部4个特征体域在20%、40%、60%、80%和100%呼吸相位下以及胸腔上4个特征体域在100%呼吸相位下的三维位移值。结果 肿瘤的位移和变形的误差在1 mm以内,胸腔的位移和变形的误差在0.5 mm以内;肿瘤在呼吸过程中沿人体竖直方向运动最大,胸腔在吸气结束时刻沿人体前后方向运动最大。结论 DVC测试技术可用于检测呼吸过程中肺部肿瘤和胸腔等胸部组织的位移和变形情况。本研究为基于DVC方法实现肺部肿瘤无创、非射线、实时的图像引导放射治疗提供了依据。     

人体运动量及能耗的测量

本论述了运动量测量的用途和意义，提出采用单位时间，单位体重的耗氧量或热量消耗来衡量运动量及能量消耗的大小，对临床上现有的各种测量方法进行了比较，着重叙述了采用运动传感器进行测量这一方法。回顾和总结了这类仪器从机械式的计步器到电子加速度计的发展过程，从中得出结论：人体在自由活动的条件下，要准确地测量运动量，以最近发展起来的加速度计最为理想。中引用了心率监测一起进行测量的一些实验数据，从理论和实验     

低温下生物组织的介电常数与电导率研究

本研究应用波导传输发射法测量生物组织在-25℃～30℃时的介电常数与电导率。首先通过测量有机材料对测量系统进行验证，证明所提出的系统具有较好的测量精度与可重复性，然后测量了在生物组织中分布很广的脂肪的介电常数与电导率，给出了一个测量值分布范围，并讨论了单个样品的介电常数与电导率随温度变化的规律。工作目的是为研究微波降温和微波复温的非热效应提供物性参数，对其机理进行探索性工作。     

心血管功能综合测定仪

本文介绍一种无创伤性心血管功能测定仪。可用于测量心脏收缩性能参数,射血前时期(PEP)和瞬时心率(HR),心脏舒张性能参数(由心阻抗图取得)及血管弹性参数,脉搏波传播速度(PV)。 仪器主要由四部分组成:(1)心电测量;(2)阻抗图测量;(3)PEP(或PV)测量;(4)HR测量。 本仪器用荧光数码管显示PEP(或PV)和HR的对应数值,心脏每搏动一次即报数一次。终端连接打印机记录数据。该仪器可用于临床诊断,重症患者监护及科研。     

便携式心率监护仪的精度和准确度

一种仪器若能舒适而准确地测量在田径场运动时的运动心率,那么它对运动员、健康活动参加者以及运动生理学研究人员是十分有价值的。便携式遥测微处理机就是这样一种仪器,它不同于在实验室建立一定条件来评估其准确度的直接EKG测量。对二十四个实验者在静止以及在轻度、中     

宽带超声衰减计算与测量系统验证的研究

宽带超声衰减(BUA)反映了骨密度疏密程度.我们简要介绍了宽带超声衰减(BUA)的测量与计算方法,给出了典型的测量结果.针对BUA测量受超声信号的频带及传感器特性影响较大的问题,制定适合目前相关仪器现状的客观标准,提出了一种验证BUA测量系统准确性的方法.     

用衰减振动式流变仪测量线性粘弹性流体粘弹性系数的新方法 理论分析部分

本文给出了测量线性粘弹性流体粘性及弹性系数的一种新方法。近年来，Kaibara和Date等发展了一种与目前普遍采用的测定流体粘性系数的仪器具有不同工作原理的新型流变仪。用该仪器测量盛有待测流体的杯子作自由衰减振动时的振动周期及衰减指数，利用一定的理论模型，就可求得流体的粘性系数。Murata、Date及Kaibara对牛顿流体的模型进行了分析计算，给出了牛顿流体粘性系数与振动周期及衰减指数的函数关系式。为使该仪器能用来测量粘弹性流体的粘性、弹性系数，本文对一种粘弹性流体模型——线性粘弹性流体进行了理论分析计算，成功地得到了流体粘性、弹性系数与衰减振动周期及衰减指数的函数关系式。并给出一些数值计算结果。这样就能够通过测量样本——杯系统的衰减振动周期及衰减指数得到线性粘弹性流体的粘性、弹性等参数，从而提供了一种新的测量线性粘弹性流体的方法。而前面提到的牛顿粘性流体的情况则为本文结果中当流体弹性系数趋于无穷时的一个特例。     

1—4 医用电子仪器漏电流检测仪

医用电子仪器在临床诊断、治疗和基础医学研究中起着十分重要的作用。但是,如果我们不注意仪器安全性检查,微安级的电流就可能引起各种电击事故。本仪器是根据卫生部颁布的(医用电气设备通用安全要求)的有关规定,为检测各类医用电子仪器的漏电流而研制的。一般数字显示仪表和磁电系仪表显示性能好,读数准确,但交、直流不能通用,必须分档测量,且测量频率范围不包括低频段。本仪器在数字显示电路前采用了交直流幅值均衡电路。被测信号通过该电路后,交流和直流得到不同的幅值。当测量交流电流     

Effects of an opioid on respiratory movements and expiratory activity in humans during isoflurane anaesthesia

Opioids increase abdominal muscle activity during anaesthesia. We proposed that opioid activity during anaesthesia would change chest wall size and movement, and contribute to ventilation. Using an optical system to measure chest wall volume, we studied 10 patients during isoflurane anaesthesia, first under the influence of an opioid and then after reversal with naloxone. Measurements were made during quiet breathing and with carbon dioxide stimulation. Airway occlusion pressure was measured to assess inspiratory and expiratory muscle activity. Chest wall volume decreased with the onset of spontaneous breathing, and decreased further when breathing was stimulated by carbon dioxide. Reversal of opioid activity increased chest wall volume. Breathing movements were predominantly abdominal. Opioid action affected the timing and amplitude of breathing but the pattern of abdominal movement was not affected. Since opioids augment abdominal muscle action during expiration, the unchanged pattern of movement can be attributed to both diaphragm and abdominal activity displacing the abdominal wall reciprocally, in the inspiratory and expiratory phases of the respiratory cycle, respectively.     

Comparison of portable apnea monitors in the detection of apnea episode during daytime rest

Although polysomnography (PSG) is the golden standard for the diagnosis of sleep apnea syndrome (SAS), access to this procedure is limited because it requires special institution and trained technicians. Therefore, many portable recording devices have been developed for detection of SAS including home monitoring. The present study evaluated the usefulness of four portable devices in detecting apneic events. The four devices are, (1) FM-500 thermister sensor type III device, (2) LS-300 pressure sensor type III device, (3) Morpheus pressure sensor type III device, and (4) SD-101, a sheet-type type IV device that detects chest wall movement. This study included 1,114 patients who underwent a daytime rest session during a routine clinic visit. The subjects were asked to remain quiet and in a supine position in a dark room. We compared the respiratory disturbance index (RDI) and number of oxygen desaturation events (OD) measured by the four portable devices in each patient. The RDI and number of OD measured by the device using the thermister sensor were significantly lower than those measured by the three other devices. These findings suggest that when using a portable recording device to screen for SAS, the characteristics of the device should be taken into account.     

涤纶布修补胸壁肿瘤切除后巨大胸壁缺损46例

背景：涤纶布作为一种临床常用耗材,取材简单,价格低廉,具有较高的坚韧度及延展性,可作为一种良好的修复材料使用。 目的：观察涤纶布用于巨大胸壁修补的实际疗效。 方法：选择46例胸壁肿瘤患者,其中男29例,女17例,年龄39-73岁。将46例患者随机均分为观察组与对照组,观察组患者切除胸壁肿瘤后采用涤纶布修补巨大胸壁缺损,对照组采用自体带蒂侧胸壁筋膜皮瓣修补巨大胸壁缺损,记录两组患者临床疗效及患者满意度。 结果与结论：术后全组病例均能胜任日常工作,无死亡及严重并发症发生,其中2例术后发生局部积液,经切口引流后好转,所有患者胸廓外观良好,呼吸运动时重建处无不适感。随访6-24个月,复查X射线片复查显示重建胸廓良好,未见移植松动、异物排斥反应、胸壁畸形等,无复发及严重并发症。观察组临床疗效及患者满意度优于对照组(P < 0.05)。结果表明涤纶布用于巨大胸壁修补的治疗,具有疗效显著、安全可靠的特点。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程      

A new sensor for monitoring chest wall motion during high-frequency oscillatory ventilation

The recently developed technique of fibre optic respiratory plethysmography (FORP) has been modified to monitor the rapid, small amplitude movements of the chest wall during high-frequency oscillatory ventilation (HFOV). The FORP sensor is an expandable belt encircling the chest, in which is housed a fibre optic loop that alters its radius of curvature as a function of chest perimeter. These curvature changes cause variations in macrobending losses of light transmitted through the fibre, which are proportional to the chest perimeter. Dynamic measurement of transmitted light intensity can hence be used to monitor chest wall motion (CWM). For application to HFOV, the design of the FORP belt was altered to increase sensitivity and the materials were chosen to maximise macrobending effects induced by the CWM. FORP was tested in four piglets ventilated with HFOV, both in the normal and surfactant-deficient lung. Measurement of CWM was possible over the full range of tidal volumes and ventilation frequencies used during HFOV. In all cases, the measured frequency of the CWM fell within 3% of the applied ventilation frequency. In addition, the technique was sufficiently sensitive to detect changes in the amplitude of CWM in response to changes in applied tidal volume. It is anticipated that application of this new non-invasive measurement device will lead to an increased understanding of the dynamics of chest and abdominal wall motion during HFOV.     

Relation of external surface to internal tumor motion studied with cine CT

The accuracy of delivering gated-radiation therapy to lung tumors using an external respiratory surrogate relies on not only interfractional and intrafractional reproducibility, but also a strong correlation between external motion and internal tumor motion. The purpose of this work was to use the cine images acquired by four-dimensional computed tomography acquisition protocol to study the relation between external surface motion and internal tumor motion. The respiratory phase information of tumor motion and chest wall motion was measured on the cine images using a proposed region-of-interest (ROI) method and compared to measurement of an external respiratory monitoring device. On eight lung patient data sets, the phase shifts were measured between (1) the signal of a real-time positioning-management (RPM) respiratory monitoring device placed in the abdominal region and four surface locations on the chest wall, (2) the RPM signal in the abdominal region and tumor motions, and (3) chest wall surface motions and tumor motions. Respiratory waveforms measured at different surface locations during the same respiratory cycle often varied and had significant phase shifts. Seven of the 8 patients showed the abdominal motion leading chest wall motion. The best correlation (smallest phase shift) was found between the abdominal motion and the superior-inferior (S-I) tumor motion. A wide range of phase shifts was observed between external surface motion and tumor anterior-posterior (A-P)/lateral motion. The result supported the placement of the RPM block in the abdominal region and suggested that during a gated therapy utilizing the RPM system, it is necessary to place the RPM block at the same location as it is during treatment simulation in order to reduce potential errors introduced by the position of the RPM block. Correlations between external motions and lateral/A-P tumor motions were inconclusive due to a combination of patient selection and the limitation of the ROI method.     

Gasless endoscopic thyroidectomy via an anterior chest wall approach using a flap-lifting system

PURPOSE: Endoscopic thyroidectomy (ET) requires a proper working space for adequate visualization of anatomical structures and proper instrument manipulation. The purpose of this prospective study was to estimate the feasibility and safety of ET using an anterior chest wall approach without gas insufflation. MATERIALS AND METHODS: The working space was created under a direct and endoscopic view through a 3-cm incision on the anterior chest wall. A retracting device was then inserted to establish the working space, and subsequent procedures were performed endoscopically. All data were reviewed using a prospective database. RESULTS: We performed 30 ETs in patients with benign thyroid tumors from December 2003 to December 2005. The procedures were completed successfully in 29 patients (mean operative time: 160.6 min; range: 90-345 min). One patient with ET was converted to open thyroidectomy secondary to substernal extension of the tumor. None of the patients developed permanent postoperative hypocalcemia or recurrent laryngeal nerve paralysis. Three patients exhibited some degree of transient recurrent laryngeal nerve palsy. CONCLUSION: These data suggest that gasless ET using an anterior chest wall approach is safe and feasible in selected patients for treating benign thyroid tumors. This technique may offer good operative working space when performed by surgeons with relatively low-volume ET practices.     

Mathematical model of chest wall mechanics: A phenomenological approach

A mathematical model of chest wall mechanics, based on a phenomenological approach to force balances, provides a quantitative framework for analyzing many types of chest wall movements by using orthogonal displacement coordinates. The moveable components of the ventilatory system include the rib cage, diaphragm, and abdomen. A distinction is made between the lung-apposed and diaphragm-apposed actions on the rib cage. The model equations are derived from “pressure” balances and geometrical relations of the compartments; the stress-displacement relations are hyperbolic. With this model we simulated stiff and flaccid chest wall behavior under normal and constrained conditions associated with abdominal compression, a Mueller maneuver, and a diaphragmatic isometric inspiration. We also examined situations that produce paradoxical as well as orthodox inspiratory movements. The results of these simulations were quantitatively consistent with available data from the literature. A phenomenon predicted by the stiff-wall model during quasi-static inspiration is that the rib cage displacement is negligible near residual volume, but then increases dramatically with lung volume. Since this mathematical model has a sound physical basis and is more comprehensive than previous models, it can be used to predict and analyze the behavior of the chest wall under a wide variety of circumstances.     

Fabrication and assembly of MEMS accelerometer-based heart monitoring device with simplified,one step placement

Abstract

An accelerometer-based heart monitoring system has been developed for real-time evaluation of heart wall movement. In this paper, assembly and fabrication of an improved device is presented along with system characterization and test data from an animal experiment. The new device is smaller and has simplified the implantation procedure compared to earlier prototypes. Leakage current recordings were well below those set by the corresponding standards.     

Leiomyoma of the extrapleural chest wall: an atypical location

Tumours of the thoracic wall constitute a wide histological spectrum. However, the literature includes very few reports of a leiomyoma occurring at the extrapleural chest wall. In this report we present our experience together with a review of the literature. Our patient was a 33-year-old woman who was diagnosed with leiomyoma of the chest wall and treated accordingly and successfully. To the best of our knowledge, this is the seventh report in the literature defining the clinical entity.     

The recording of heart vibrations: a problem of vibration measurement on soft tissue

The determination of the effect of loading of the chest wall exerted by a contact phonocardiographic microphone, has been attempted in earlier investigations by the measurement of the mechanical properties of the microphone and the chest wall in combination with mechanical models describing the coupling phenomenon (method 1). For computing the acceleration response of the microphone applied to the chest wall a number of unverified assumptions were made. In the paper a method is described for experimental determination of the coupling characteristic. A specially designed ultralight pick-up (1 g) was applied for recording the quasi-unloaded vibrations and the average amplitude spectrum was calculated. The procedure was repeated at the same site, the chest wall successively being loaded with different masses and two commercial microphones (method 2). Logarithmic transfer functions of the loaded to unloaded situations have been computed. The experiments were performed on six healthy persons. The results of method 1 appeared to be very similar to those obtained with method 2 when a Verburg model was assumed. In this manner we determined the acceleration response of microphones applied to the chest wall, which is both of interest for standardised and quantitative phonocardiography.