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Measuring Intra/Extracellular Volume and Hemodynamics

测量细胞内/外体积和血流动力学

基本信息

批准号：
6691141
负责人：
Leslie David Montgomery
金额：
$ 10.03万
依托单位：
LDM ASSOCIATES
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-09-01 至 2004-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6691141
关键词：
adolescence (12-20) adult human (21+) biomedical equipment development blood volume clinical research electrical impedance extracellular fluid flow hemodynamics human subject intracellular nonblood rheology noninvasive diagnosis patient oriented research plethysmography time resolved data

项目摘要

DESCRIPTION (provided by applicant): A device capable of noninvasive real-time measurement of intravascular and extravascular fluid volumes and blood flows does not currently exist. Such a device would provide vital information in the treatment of diverse pathophysiologic fluid volume and hemodynamic states including, for example, the management of increased intracranial pressure following trauma, the treatment of disequilibrium and hypotension during renal dialysis, the monitoring of hydrational state of premature infants, and the investigation and diagnosis of orthostatic intolerance associated with dysautonomia and space flight. Currently employed methods are either invasive, such as tracer dilution techniques, or bulky and expensive such as MRI technologies, and often do not yield easily used real-time data during physiologic stress. The central objective of this proposal is to perfect and test a bioelectric impedance device capable of measuring blood flows by impedance plethysmography (IPG) and of measuring compartmental fluid volumes by electrical impedance spectrography (EIS). Fixed frequency bioimpedance by IPG has been reliably used to estimate blood flow and intravascular volume shifts. Swept frequency bioimpedance by EIS has been used to estimate intravascular, interstitial and intracellular fluid volumes. We will base the IPG module of the device on the fixed frequency Tetrapolar High Resolution Impedance Monitor (THRIM Model 2994-D) digital impedance plethysmograph that was developed by UFi, Inc. This employs a fixed frequency of 50 KHz and has been extensively benchmarked in animal and human blood flow studies. For EIS operation, 40 different frequencies will be provided, at log intervals, between 3 and 300 KHz. EIS will use a constant current transformer coupled excitation stage in conjunction with a digital demodulation stage to supply both resistive and reactive impedance components. This will be controlled by a microprocessor system connected via an RS-232 serial interface to PC analysis software. The microprocessor control system will store impedance parameters and signal waveform segments prior to supplying the data to the host for on-line real time analysis and display. Host software will use a deconvolution algorithm to obtain parameters for an R-C equivalent circuit used to model the intravascular, interstitial and intracellular fluid spaces. In this first stage of development we will test the device against a Whitney strain gauge system using occlusion cuffs to 1) measure forearm and calf blood flows in order to validate the IPG module; 2) produce controlled increases in interstitial and intravascular volumes by stepwise venous occlusion to validate the EIS module. It is hoped that the instrument may be further validated during statistically significant clinical trials during a Phase II NIH SBIR grant.

描述（由申请人提供）：目前还不存在能够无创实时测量血管内和血管外流体体积和血流的设备。这种装置将在治疗不同的病理生理流体体积和血液动力学状态中提供重要信息，包括例如创伤后颅内压升高的管理、肾透析期间失衡和低血压的治疗、早产儿的水合状态的监测以及与自主神经功能障碍和空间飞行相关的直立性不耐受的研究和诊断。目前采用的方法或者是侵入性的，例如示踪剂稀释技术，或者是庞大且昂贵的，例如MRI技术，并且通常在生理应激期间不产生容易使用的实时数据。该提案的中心目标是完善和测试能够通过阻抗体积描记法（IPG）测量血流和通过电阻抗谱法（EIS）测量房室流体体积的生物电阻抗装置。IPG的固定频率生物阻抗已可靠地用于估计血流量和血管内容量变化。通过EIS的扫频生物阻抗已被用于估计血管内、间质和细胞内液体体积。我们将在UFi，Inc.开发的固定频率四极高分辨率阻抗监护仪（THRIM型号2994-D）数字阻抗体积描记器上安装器械的IPG模块。这采用了50 KHz的固定频率，并已在动物和人体血流研究中得到广泛的基准。对于EIS操作，将提供40个不同的频率，以对数间隔，在3和300 KHz之间。EIS将使用一个恒流Transformer耦合激励级和一个数字解调级，以提供电阻和电抗阻抗分量。这将由通过RS-232串行接口连接到PC分析软件的微处理器系统控制。微处理器控制系统在将数据提供给主机进行在线真实的实时分析和显示之前，将阻抗参数和信号波形段存储起来。主机软件将使用去卷积算法获得用于模拟血管内、间质和细胞内液空间的R-C等效电路的参数。在开发的第一阶段，我们将使用闭塞袖带对器械进行Whitney应变计系统测试，以1）测量前臂和小腿血流，以确认IPG模块; 2）通过逐步静脉闭塞产生间质和血管内容量的受控增加，以确认EIS模块。希望该仪器可以在NIH SBIR资助的第二阶段统计学显著临床试验期间得到进一步验证。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Measurement of Cerebral Blood Flow Autoregulation with Rheoencephalography: A Comparative Pig Study.

DOI：
10.2478/joeb-2018-0017
发表时间：
2018-01-01
期刊：
Journal of electrical bioimpedance
影响因子：
0
作者：
Bodo, Michael;D Montgomery, Leslie;Armonda, Rocco
通讯作者：
Armonda, Rocco

Monitoring intracellular, interstitial, and intravascular volume changes during fluid management procedures.

DOI：
10.1007/s11517-013-1064-3
发表时间：
2013-10
期刊：
MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING
影响因子：
3.2
作者：
Montgomery, Leslie D.;Gerth, Wayne A.;Montgomery, Richard W.;Lew, Susie Q.;Klein, Michael M.;Stewart, Julian M.;Velasquez, Manuel T.
通讯作者：
Velasquez, Manuel T.

Segmental Volume and Circulatory Changes that Occur in Humans and Rhesus Monkeys During 4 Hour, -6 Degree Head Down Tilt.