• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Near-infrared spectroscopy in continuous monitoring of cerebral oxygenation during gravitational (+Gz) acceleration and in vivo experiments.
【24h】

Near-infrared spectroscopy in continuous monitoring of cerebral oxygenation during gravitational (+Gz) acceleration and in vivo experiments.

机译：近红外光谱法在重力（+ Gz）加速和体内实验期间连续监测大脑氧合作用。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Near-infrared spectroscopy (NIRS) is an optically based technique to noninvasively and continuously monitor brain and other tissue oxygenation by determining relative changes in oxyhemoglobin ( D HbO2) and deoxyhemoglobin ( D Hb). The Modified Beer-Lambert Law is used to distinguish D HbO2 from D Hb. The summation of D Hb and D HbO2 gives the relative change in total hemoglobin ( D TotalHb) which is an important hemodynamic parameter that is proportional to changes in blood volume. The NIRS oxygenation indexes {lcub} D HbO2- D Hb{rcub} and D rSO2 ( ≈D HbO2/ D TotalHb) provide information on the relative change in mixed venous oxygen saturation.; By using low power, narrow spectral bandwidth laser diodes to determine the Beer-Lambert parameters, it was possible to construct a small, relatively inexpensive NIRS device. Insights on the clinical interpretation of the NIRS parameters were obtained through different animal and human research studies. Induced physiological changes resulted in predictable changes of the NIRS parameters.; Two major studies are presented in this dissertation. The first study investigated the changes of the NIRS parameters in response to changes in arterial carbon dioxide (PaCO2) levels in piglets. D HbO2 and D TotalHb increased nearly linearly, corresponding to the characteristic increase of the cerebral vascular dilation with increasing depth of hypercapnia, but D Hb remained relatively constant. The expression D TotalHb/ D PaCO2 was also studied because it represents the CO 2-reactivity of the cerebral vasculature. Poor CO2-reactivity indicates possible failure of the cerebral autoregulation system, leaving the brain vulnerable to ischemic insult.; The second study involved the use of NIRS in an U.S. Navy centrifuge. In this unique study, human subjects were exposed to high +Gz acceleration and were induced to lose consciousness. During successive high +Gz pulses of increasing pulse width, the subjects experienced increasing vision loss levels, confusion and disorientation (A-LOC), to loss of consciousness (G-LOC). The NIRS parameters were correlated with the resultant subject +Gz stress symptoms. The results show that the magnitude of the hyperemic response recovery phase after the +Gz pulse, as determined by D HbO2 and D TotalHb, was significantly increased for A-LOC and G-LOC symptoms.
机译：近红外光谱（NIRS）是一种基于光学的技术，可通过确定氧合血红蛋白（D HbO2）和脱氧血红蛋白（D Hb）的相对变化来无创地连续监测大脑和其他组织的氧合。修正比尔-朗伯定律用于区分D HbO2和D Hb。 D Hb和D HbO2的总和给出了总血红蛋白的相对变化（D TotalHb），这是一个重要的血液动力学参数，与血容量的变化成比例。 NIRS的氧合指数{lcub} D HbO 2 -D Hb {rcub}和D rSO 2（ΔDHbO 2 / D TotalHb）提供了关于混合静脉血氧饱和度的相对变化的信息。通过使用低功率，窄光谱带宽的激光二极管来确定Beer-Lambert参数，可以构建一个小型，相对便宜的NIRS设备。通过不同的动物和人类研究获得了有关NIRS参数临床解释的见解。诱导的生理变化导致可预测的NIRS参数变化。本文提出了两项​​主要研究。第一项研究调查了NIRS参数对仔猪动脉二氧化碳（PaCO2）水平变化的响应。 D HbO 2和D TotalHb几乎呈线性增加，与高碳酸血症深度增加时脑血管扩张的特征增加相对应，但D Hb保持相对恒定。还研究了表达D TotalHb / D PaCO2，因为它代表了脑血管的CO 2反应性。 CO2反应性差表明大脑自动调节系统可能失效，使大脑容易受到缺血性损伤。第二项研究涉及在美国海军离心机中使用NIRS。在这项独特的研究中，人类受试者暴露于高+ Gz加速度下并被诱导失去意识。在连续的高+ Gz脉冲增加脉冲宽度的过程中，受试者经历了视力丧失，意识错乱（A-LOC）和意识丧失（G-LOC）的增加。 NIRS参数与产生的受试者+ Gz应激症状相关。结果表明，由D HbO2和D TotalHb确定的+ Gz脉冲后的充血反应恢复阶段的幅度对于A-LOC和G-LOC症状显着增加。

著录项

  • 作者

    Benni, Paul Bryan.;

  • 作者单位

    Rutgers The State University of New Jersey - New Brunswick.;

  • 授予单位 Rutgers The State University of New Jersey - New Brunswick.;
  • 学科 Biology Animal Physiology.; Engineering Biomedical.; Health Sciences Medicine and Surgery.; Biophysics Medical.
  • 学位 Ph.D.
  • 年度 1999
  • 页码 222 p.
  • 总页数 222
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 生理学;生物医学工程;生物物理学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号