JoVE Journal > Medicine
Summary
Abstract
Introduction
Protocol
Results
Discussion
Disclosures
Acknowledgements
Materials
References
자동 번역
Please note that all translations are automatically generated. Click here for the English version.
의학

使用漫反射光谱实时监测神经危重症患者

Published: November 19, 2020
doi:
10.3791/61608
, , , , , , , , ,
1Institute of Physics,University of Campinas, 2Brazilian Institute of Neuroscience and Neurotechnology, 3Clinical Hospital,University of Campinas, 4Department of Emergency Medicine,Albert Einstein College of Medicine, 5School of Medical Sciences,University of Campinas

Summary

这里介绍的是一种方案，用于使用漫反射光学器件实时和在床边实时无创监测神经危重患者的脑血流动力学。具体而言，该协议使用混合漫反射光学系统来检测和显示有关脑氧合，脑血流和脑代谢的实时信息。

Abstract

神经生理学监测是神经危重症患者治疗的一个重要目标，因为它可以预防继发性损伤并直接影响发病率和死亡率。然而，目前缺乏合适的非侵入性实时技术来连续监测床边的脑生理。弥漫光学技术已被提出作为神经危重患者床旁测量脑血流量和脑氧合的潜在工具。以前已经探索过漫反射光谱法，以监测从新生儿监测到成人脑血管介入治疗等多种临床场景的患者。然而，该技术通过在床边提供实时信息来帮助临床医生的可行性在很大程度上仍未得到解决。在这里，我们报告了漫反射光学系统的翻译，用于在重症监护期间连续实时监测脑血流量，脑氧合和脑氧代谢。该仪器的实时功能可以实现基于患者特定脑生理学的治疗策略，而不是依赖于替代指标，例如动脉血压。通过使用相对便宜和便携式的仪器在不同时间尺度上提供有关脑循环的实时信息，这种方法在低预算医院、偏远地区和开放领域（例如国防和体育）的监测中可能特别有用。

Introduction

导致危重神经系统患者预后不良的大多数并发症与脑血流动力学损伤引起的继发性损伤有关。因此，监测这些患者的脑生理可能直接影响发病率和死亡率1，2，3，4，5，6，7。然而，目前还没有成熟的临床工具用于在床边对神经危重患者的脑生理进行连续实时无创监测。在潜在的候选者中，漫反射光学技术最近被提出作为填补这一空白的有前途的工具8，9，10，11。通过测量来自头皮的漫射近红外光（~650-900 nm）的缓慢变化（即数十到数百毫秒），漫反射光谱（DOS）可以测量大脑中主要发色团的浓度，例如脑氧（HbO）和脱氧血红蛋白（HbR）12，13。此外，可以通过量化光强度的快速波动（即从几μs到几毫秒）来测量脑血流量（CBF）10，14，15，16，17。当结合时，DOS和DCS还可以提供大脑代谢率的估计值（CMRO2）18，19，20。

已经探索了DOS和DCS的组合，以在几种临床前和临床情况下监测患者。例如，漫反射光学已被证明可以为危重新生儿提供相关的临床信息 21，22，23，24，包括在心脏手术期间治疗心脏缺陷 23，25，26，27，28.此外，几位作者还探索了在不同脑血管介入治疗过程中使用漫反射光学来评估脑血流动力学，例如颈动脉内膜切除术29、30、31、中风溶栓治疗32、床头操作33、34、35、心肺复苏36 和其他 37，38，39.当连续血压监测也可用时，漫反射光学器件可用于监测健康和危重受试者的大脑自动调节11，40，41，42，以及评估脑循环的临界闭合压力43。几位作者已经根据不同的金标准CBF测量18验证了DCS的CBF测量结果，而使用漫反射光学器件测量的CMRO2已被证明是神经关键监测的有用参数8，18，23，24，28，43，44，45.此外，先前的研究已经验证了光学衍生的脑血流动力学参数用于长期监测神经危重症患者8，9，10，11，包括用于预测缺氧46，47，48和缺血事件8。

漫反射光学技术在纵向测量和临床干预期间提供有价值的实时信息的可靠性在很大程度上仍未得到解决。以前将独立DOS系统的使用与侵入性脑组织氧张力监测仪进行比较，并且DOS被认为没有足够的敏感性来取代侵入性监测仪。然而，除了使用相对较小的人群外，侵入性和非侵入性监测仪的直接比较可能会被误导，因为每种技术探测包含大脑脉管系统不同部分的不同体积。尽管这些研究最终得出结论，漫反射光学器件不能替代侵入性监视器，但在这两项研究中，DOS都达到了中等到良好的精度，这对于没有侵入性监视器的情况和/或地方可能足够了。

相对于其他方法，漫反射光学器件的主要优点是它能够使用便携式仪器在床边无创（连续）同时测量血流和组织血氧合。与经颅多普勒超声（TCD）相比，DCS还有一个额外的优势：它在组织水平上测量灌注，而TCD测量大脑底部大动脉的脑血流速度。在评估近端大动脉血流和软脑膜侧支均有助于灌注的狭窄闭塞性疾病时，这种区别可能尤为重要。与其他传统成像模式（如正电子发射断层扫描（PET）和磁共振成像（MRI））相比，光学技术也具有优势。除了同时提供CBF和HbO/HbR浓度的直接测量（单独使用MRI或PET无法实现）外，光学监测还提供了明显更好的时间分辨率，例如，允许评估动态脑自动调节40，41，42和评估动态演变的血流动力学变化。此外，与PET和MRI相比，漫射光学仪器价格低廉且便于携带，鉴于中低收入国家血管疾病的高负担，这是一个关键优势。

这里提出的协议是对重症监护病房（ICU）的患者进行实时床边神经监测的环境。该方案使用混合光学设备以及临床友好的图形用户界面（GUI）和定制的光学传感器来探测患者（图1）。用于展示该协议的混合系统结合了来自独立模块的两个漫反射光谱：商用频域（FD-）DOS模块和自制DCS模块（图1A）。FD-DOS 模块49，50 由 4 个光电倍增管 （PMT） 和 32 个以四种不同波长（690、704、750 和 850 nm）发射的激光二极管组成。DCS 模块由一个发射 785 nm 的长相干激光器、16 个作为探测器的单光子计数器和一个相关器板组成。FD-DOS模块的采样频率为10 Hz，DCS模块的最大采样频率为3 Hz。为了集成FD-DOS和DCS模块，在我们的控制软件中编程了一个微控制器，以便在每个模块之间自动切换。微控制器负责打开和关闭FD-DOS和DCS激光器，以及FD-DOS探测器，以允许对每个模块进行交错测量。总的来说，所提出的系统可以每0.5至5秒收集一个FD-DOS和DCS组合样本，具体取决于信噪比（SNR）要求（收集时间越长，SNR越好）。为了将光耦合到额头，我们开发了一种3D打印的光学探头，可以为每个患者定制（图1B），源检测器的间隔在0.8到4.0厘米之间变化。此处示例中使用的标准源检测器分离对于DCS为2.5 cm，对于FD-DOS为1.5、2.0、2.5和3.0 cm。

本研究中提出的协议的主要特征是开发了一个实时界面，既可以使用友好的GUI控制硬件，又可以在不同的时间窗口下实时显示主要的大脑生理参数（图1C）。在所提出的GUI中开发的实时分析管道速度快，计算光学参数所需的时间不到50 ms（有关更多详细信息，请参阅 补充材料 ）。GUI的灵感来自神经ICU现有的临床仪器，并在将系统转换为神经ICU期间，通过临床用户的广泛反馈进行了调整。因此，实时GUI可以促进常规医院工作人员（如神经重症监护医生和护士）采用光学系统。漫反射光学作为临床研究工具的广泛采用有可能增强其监测生理上有意义的数据的能力，并最终证明漫反射光学是实时无创监测神经关键患者的良好选择。

Protocol

该协议由坎皮纳斯大学地方委员会批准（协议号56602516.2.0000.5404）。在测量之前，从患者或法定代表人那里获得了书面知情同意。我们监测了坎皮纳斯大学诊所医院收治的患者，诊断为缺血性中风或影响前循环的蛛网膜下腔出血。影响后循环的缺血性中风患者，由于颅内压升高而导致减压性颅骨切除术的患者和其他神经退行性疾病（痴呆，帕金森氏症或任何其他可能与皮质萎缩相关的疾病）的患?…

Representative Results

理想情况下，使用DCS模块获得的归一化自相关曲线在零延迟时间外推（使用单模光纤14时）应约为1.5，并且在较长的延迟时间下，曲线应衰减至1。曲线应该是平滑的，对于较长的源-检测器分离，它应该具有更快的衰减。 图2A显示了良好自相关的示例。 图2B 显示了不良自相关曲线的示例;在本例中，无法区分不同源检测器分离的曲线。 …

Discussion

本文提出了一种混合光学系统，该系统可以在旁边提供神经危重症患者的脑血流、脑氧合和脑氧代谢的实时信息。弥漫光学技术的使用以前曾被认为是临床情况下非侵入性床旁监测的潜在标志物。之前的一项研究通过病例报告9重点关注神经ICU住院期间光学监测的临床方面和可行性。这项工作的重点是详细说明与漫反射光学实时监测相关的相关和创新方面。具体来说，本文提出了…

Disclosures

The authors have nothing to disclose.

Acknowledgements

我们感谢圣保罗研究基金会 （FAPESP） 通过第 2012/02500-8 （RM）、2014/25486-6 （RF） 和 2013/07559-3 号文件提供的支持。资助者在研究设计、数据收集和分析、发表决定或手稿准备方面没有任何作用。

Materials

3D Printer Sethi3D S2 3D-printer used to print the customizable probes
Arduino UNO Arduino UNO REV3 Microcontroller responsible to interleave the DCS and FD-DOS measurements
DCS Correlator Correlator.com Flex11-16ch Component of the DCS module
DCS Dectectors IO Boards Excelitas Technology SPCM-AQ4C-IO Component of the DCS module
DCS Detectors Excelitas Technology SPCM-AQ4C Component of the DCS module
DCS Laser CrystaLaser DL785-120-SO Component of the DCS module
DCS Power supply Artesyn UMP10T-S2A-S2A-S2A-S2A-IES-00-A Component of the DCS module (power supply for the DCS detecto; 2, 5 and 30V)
FD-DOS fibers ISS Imagent supplies The fibers used for FD-DOS detection and illumination are provived by ISS
Flexible 3D printer material Sethi3D NinjaFlex Material used to print the flexible customizable probes
Imagent ISS Imagent FD-DOS module
Laser safety googles Thorlabs LG9
Multi-mode fiber Thorlabs FT400EMT Multi-mode fiber used for DCS illumination
Neutral density filter 1.0 OD Edmund Optics 53-705 Neutral density filter for the short source detector separations
Single-mode optical fiber Thorlabs 780HP Single-mode optical fiber used for the DCS detectors
System battery SMS NET4 System battery used for transportation
DOWNLOAD MATERIALS LIST

References

  1. Papanikolaou, J., et al. Cardiac and central vascular functional alterations in the acute phase of aneurysmal subarachnoid hemorrhage. Critical Care Medicine. 40 (1), 223-232 (2012).
  2. Sarrafzadeh, A. S., Vajkoczy, P., Bijlenga, P., Schaller, K. Monitoring in neurointensive care – The challenge to detect delayed cerebral ischemia in high grade aneurysmal SAH. Frontiers in Neurology. 5 (134), (2014).
  3. Messerer, M., Daniel, R. T., Oddo, M. Neuromonitoring after major neurosurgical procedures. Minerva Anestesiologica. 78 (7), 810-822 (2012).
  4. Le Roux, P., et al. Consensus summary statement of the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care: A statement for healthcare professionals from the Neurocritical Care Society and the European Society of Intensive Care Medicine. Intensive Care Medicine. 40 (9), 1189-1209 (2014).
  5. Roh, D., Park, S. Brain Multimodality Monitoring: Updated Perspectives. Current Neurology and Neuroscience Reports. 16 (6), 1-10 (2016).
  6. Oddo, M., Villa, F., Citerio, G. Brain multimodality monitoring: An update. Current Opinion in Critical Care. 18 (2), 111-118 (2012).
  7. Sandsmark, D. K., Kumar, M. A., Park, S., Levine, J. M. Multimodal Monitoring in Subarachnoid Hemorrhage. Stroke. 43 (5), 1440-1445 (2012).
  8. Baker, W. B., et al. Continuous non-invasive optical monitoring of cerebral blood flow and oxidative metabolism after acute brain injury. Journal of Cerebral Blood Flow and Metabolism. 39 (8), 1469-1485 (2019).
  9. Menezes Forti, R., et al. Real-time non-invasive assessment of cerebral hemodynamics with diffuse optical spectroscopies in a neuro intensive care unit: an observational study. Frontiers in Medicine. 7 (147), (2020).
  10. Kim, M. N., et al. Noninvasive measurement of cerebral blood flow and blood oxygenation using near-infrared and diffuse correlation spectroscopies in critically brain-injured adults. Neurocritical Care. 12 (2), 173-180 (2010).
  11. Selb, J., et al. Prolonged monitoring of cerebral blood flow and autoregulation with diffuse correlation spectroscopy in neurocritical care patients. Neurophotonics. 5 (04), 1 (2018).
  12. Durduran, T., Choe, R., Baker, W. B., Yodh, A. G. Diffuse optics for tissue monitoring and tomography. Reports on Progress in Physics. 73 (7), 76701 (2010).
  13. Jacques, S. L. Optical properties of biological tissues: a review. Physics in Medicine and Biology. 58 (11), 37-61 (2013).
  14. Durduran, T., Yodh, A. G. Diffuse correlation spectroscopy for non-invasive, micro-vascular cerebral blood flow measurement. NeuroImage. 85, 5163 (2014).
  15. Durduran, T., et al. Diffuse optical measurement of blood flow, blood oxygenation, and metabolism in a human brain during sensorimotor cortex activation. Optics Letters. 29 (15), 1766 (2004).
  16. Selb, J., et al. Sensitivity of near-infrared spectroscopy and diffuse correlation spectroscopy to brain hemodynamics: simulations and experimental findings during hypercapnia. Neurophotonics. 1 (1), 15005 (2014).
  17. Shang, Y., Li, T., Yu, G. Clinical applications of near-infrared diffuse correlation spectroscopy and tomography for tissue blood flow monitoring and imaging. Physiological Measurement. 38 (4), 1-26 (2017).
  18. Mesquita, R. C., et al. Direct measurement of tissue blood flow and metabolism with diffuse optics. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 369 (1955), 4390-4406 (2011).
  19. Culver, J. P., et al. Diffuse optical tomography of cerebral blood flow, oxygenation, and metabolism in rat during focal ischemia. Journal of Cerebral Blood Flow and Metabolism. 23 (8), 911-924 (2003).
  20. Valabrègue, R., Aubert, A., Burger, J., Bittoun, J., Costalat, R. Relation between Cerebral Blood Flow and Metabolism Explained by a Model of Oxygen Exchange. Journal of Cerebral Blood Flow and Metabolism. 23 (5), 536-545 (2003).
  21. Farzam, P., et al. Shedding light on the neonatal brain: probing cerebral hemodynamics by diffuse optical spectroscopic methods. Scientific Reports. 7 (1), 15786 (2017).
  22. Wong, F. Cerebral blood flow measurements in the neonatal brain. Prenatal and Postnatal Determinants of Development. 109, 69-87 (2016).
  23. Busch, D. R., et al. Noninvasive optical measurement of microvascular cerebral hemodynamics and autoregulation in the neonatal ECMO patient. Pediatric Research. , 1-9 (2020).
  24. Dehaes, M., et al. Cerebral oxygen metabolism in neonatal hypoxic ischemic encephalopathy during and after therapeutic hypothermia. Journal of Cerebral Blood Flow and Metabolism. 34 (1), 87-94 (2014).
  25. Ferradal, S. L., et al. Non-invasive assessment of cerebral blood flow and oxygen metabolism in neonates during hypothermic cardiopulmonary bypass: Feasibility and clinical implications. Scientific Reports. 7 (1), 44117 (2017).
  26. Busch, D. R., et al. Continuous cerebral hemodynamic measurement during deep hypothermic circulatory arrest. Biomedical Optics Express. 7 (9), 3461 (2016).
  27. Wang, D., et al. Fast blood flow monitoring in deep tissues with real-time software correlators. Biomedical Optics Express. 7 (3), 776 (2016).
  28. Ko, T. S., et al. Non-invasive optical neuromonitoring of the temperature-dependence of cerebral oxygen metabolism during deep hypothermic cardiopulmonary bypass in neonatal swine. Journal of Cerebral Blood Flow & Metabolism. 40 (1), 187-203 (2018).
  29. Pennekamp, C. W. A. A., et al. Near-infrared spectroscopy can predict the onset of cerebral hyperperfusion syndrome after carotid endarterectomy. Cerebrovascular Diseases. 34 (4), 314-321 (2012).
  30. Pennekamp, C. W. A. A., Bots, M. L., Kappelle, L. J., Moll, F. L., de Borst, G. J. The Value of Near-Infrared Spectroscopy Measured Cerebral Oximetry During Carotid Endarterectomy in Perioperative Stroke Prevention. A Review. European Journal of Vascular and Endovascular Surgery. 38 (5), 539-545 (2009).
  31. Shang, Y., et al. Cerebral monitoring during carotid endarterectomy using near-infrared diffuse optical spectroscopies and electroencephalogram. Physics in Medicine and Biology. 56 (10), 3015-3032 (2011).
  32. Delgado-Mederos, R., et al. Transcranial diffuse optical assessment of the microvascular reperfusion after thrombolysis for acute ischemic stroke. Biomedical Optics Express. 9 (3), 1262 (2018).
  33. Favilla, C. G., et al. Optical Bedside Monitoring of Cerebral Blood Flow in Acute Ischemic Stroke Patients During Head-of-Bed Manipulation. Stroke. 45 (5), 1269-1274 (2014).
  34. Gregori-Pla, C., et al. Early microvascular cerebral blood flow response to head-of-bed elevation is related to outcome in acute ischemic stroke. Journal of Neurology. 266 (4), 990-997 (2019).
  35. Kim, M. N., et al. Continuous optical monitoring of cerebral hemodynamics during head-of-bed manipulation in brain-injured adults. Neurocritical Care. 20 (3), 443-453 (2014).
  36. Ko, T., et al. Prediction of Return of Spontaneous Circulation During Cardiopulmonary Resuscitation using Frequency-Domain Diffuse Optical Spectroscopy in a Pediatric Swine Model of Asphyxial Cardiac Arrest. Biophotonics Congress: Biomedical Optics Congress 2018 (Microscopy/Translational/Brain/OTS). , (2018).
  37. Favilla, C. G., et al. Non-invasive respiratory impedance enhances cerebral perfusion in healthy adults. Frontiers in Neurology. 8, (2017).
  38. Favilla, C. G., et al. Perfusion Enhancement with Respiratory Impedance After Stroke (PERI-Stroke). Neurotherapeutics. 16 (4), 1296-1303 (2019).
  39. Ritzenthaler, T., et al. Cerebral near-infrared spectroscopy a potential approach for thrombectomy monitoring. Stroke. 48 (12), 3390-3392 (2017).
  40. Fantini, S., Sassaroli, A., Tgavalekos, K. T., Kornbluth, J. Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods. Neurophotonics. 3 (3), 31411 (2016).
  41. Parthasarathy, A. B., et al. Dynamic autoregulation of cerebral blood flow measured non-invasively with fast diffuse correlation spectroscopy. Journal of Cerebral Blood Flow and Metabolism. 38 (2), 230-240 (2018).
  42. Kainerstorfer, J. M., Sassaroli, A., Tgavalekos, K. T., Fantini, S. Cerebral autoregulation in the microvasculature measured with near-infrared spectroscopy. Journal of Cerebral Blood Flow and Metabolism. 35 (6), 959-966 (2015).
  43. Baker, W. B., et al. Noninvasive optical monitoring of critical closing pressure and arteriole compliance in human subjects. Journal of Cerebral Blood Flow and Metabolism. 37 (8), 2691-2705 (2017).
  44. Lin, P. Y., et al. Non-invasive optical measurement of cerebral metabolism and hemodynamics in infants. Journal of Visualized Experiments. (73), e4379 (2013).
  45. Wintermark, P., Hansen, A., Warfield, S. K., Dukhovny, D., Soul, J. S. Near-infrared spectroscopy versus magnetic resonance imaging to study brain perfusion in newborns with hypoxic-ischemic encephalopathy treated with hypothermia. NeuroImage. 85, 287-293 (2014).
  46. Busch, D. R., et al. Detection of brain hypoxia based on noninvasive optical monitoring of cerebral blood flow with diffuse correlation spectroscopy. Neurocritical Care. 30 (1), 72-80 (2019).
  47. Davies, D. J., et al. Cerebral oxygenation in traumatic brain injury: Can a non-invasive frequency domain near-infrared spectroscopy device detect changes in brain tissue oxygen tension as well as the established invasive monitor. Journal of Neurotrauma. 36 (7), 1175-1183 (2019).
  48. Leal-Noval, S. R., et al. Invasive and noninvasive assessment of cerebral oxygenation in patients with severe traumatic brain injury. Intensive Care Medicine. 36 (8), 1309-1317 (2010).
  49. Fantini, S., Franceschini, M. A., Fishkin, J. B., Barbieri, B., Gratton, E. Quantitative determination of the absorption spectra of chromophores in strongly scattering media: a light-emitting-diode based technique. Applied Optics. 33 (22), 5204 (1994).
  50. Fantini, S., et al. Frequency-domain multichannel optical detector for noninvasive tissue spectroscopy and oximetry. Optical Engineering. 34 (1), 32 (1995).
  51. Carpenter, D. A., Grubb, R. L., Tempel, L. W., Powers, W. J. Cerebral oxygen metabolism after aneurysmal subarachnoid hemorrhage. Journal of Cerebral Blood Flow and Metabolism. 11 (5), 837-844 (1991).
  52. Johansen-Berg, H., et al. The role of ipsilateral premotor cortex in hand movement after stroke. Proceedings of the National Academy of Sciences, U.S.A. 99 (22), 14518-14523 (2002).
  53. Hunt, W. E., Hess, R. M. Surgical risk as related to time of intervention in the repair of intracranial aneurysms. Journal of Neurosurgery. 28 (1), 14-20 (1968).
  54. Fisher, C. M., Kistler, J. P., Davis, J. M. Relation of Cerebral Vasospasm to Subarachnoid Hemorrhage Visualized by Computerized Tomographic Scanning. Neurosurgery. 6 (1), 1-9 (1980).
  55. Carey, J. R., et al. Analysis of fMRI and finger tracking training in subjects with chronic stroke. Brain. 125 (4), 773-788 (2002).
  56. Lindenberg, R., Renga, V., Zhu, L. L., Nair, D., Schlaug, G. Bihemispheric brain stimulation facilitates motor recovery in chronic stroke patients. Neurology. 75 (24), 2176-2184 (2010).
  57. Schaechter, J. D., et al. Motor recovery and cortical reorganization after constraint-induced movement therapy in stroke patients: A preliminary study. Neurorehabilitation and Neural Repair. 16 (4), 326-338 (2002).
  58. Dehaes, M., et al. Assessment of the frequency-domain multi-distance method to evaluate the brain optical properties: Monte Carlo simulations from neonate to adult. Biomedical Optics Express. 2 (3), 552 (2011).
  59. Fantini, S., Sassaroli, A. Frequency-domain techniques for cerebral and functional near-infrared spectroscopy. Front Neurosci. 14, 1-18 (2020).
  60. Blaney, G., Sassaroli, A., Pham, T., Fernandez, C., Fantini, S. Phase dual-slopes in frequency-domain near-infrared spectroscopy for enhanced sensitivity to brain tissue: First applications to human subjects. Journal of Biophotonics. 13 (1), 201960018 (2020).
  61. Abdalsalam, O., O’Sullivan, T. D., Howard, S., Zhang, Y. Self-calibrated frequency domain diffuse optical spectroscopy with a phased source array. Optical Tomography and Spectroscopy of Tissue XIII Conference. 1087403, 2 (2019).
  62. Applegate, M. B., Istfan, R. E., Spink, S., Tank, A., Roblyer, D. Recent advances in high speed diffuse optical imaging in biomedicine Recent advances in high speed diffuse optical imaging in biomedicine. APL Photonics. 5, 040802 (2020).
  63. Torricelli, A., et al. Time domain functional NIRS imaging for human brain mapping. NeuroImage. 85, 28-50 (2014).
  64. Pifferi, A., et al. New frontiers in time-domain diffuse optics , a review. Journal of Biomedical Optics. 21 (9), 091310 (2016).
  65. Gagnon, L., Desjardins, M., Jehanne-Lacasse, J., Bherer, L., Lesage, F. Investigation of diffuse correlation spectroscopy in multi-layered media including the human head. Optics Express. 16 (20), 15514 (2008).
  66. Verdecchia, K., et al. Assessment of a multi-layered diffuse correlation spectroscopy method for monitoring cerebral blood flow in adults. Biomedical Optics Express. 7 (9), 3659 (2016).
  67. Liemert, A., Kienle, A. Light diffusion in a turbid cylinder II Layered case. Optics Express. 18 (9), 9266 (2010).
  68. Hallacoglu, B., Sassaroli, A., Fantini, S. Optical characterization of two-layered turbid media for non-invasive, absolute oximetry in cerebral and extracerebral tissue. PLoS One. 8 (5), 64095 (2013).
  69. Alexandrakis, G., Busch, D. R., Faris, G. W., Patterson, M. S. Determination of the optical properties of two-layer turbid media by use of a frequency-domain hybrid Monte Carlo diffusion model. Applied Optics. 40 (22), 3810 (2001).
  70. Martelli, F., Sassaroli, A., Del Bianco, S., Yamada, Y., Zaccanti, G. Solution of the time-dependent diffusion equation for layered diffusive media by the eigenfunction method. Physical Review E – Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics. 67 (5), 14 (2003).
  71. Mesquita, R. C., et al. Influence of probe pressure on the diffuse correlation spectroscopy blood flow signal: extra-cerebral contributions. Biomedical Optics Express. 4 (7), 978 (2013).
  72. Wang, D., et al. Influence of probe pressure on the pulsatile diffuse correlation spectroscopy blood flow signal on the forearm and forehead regions. Neurophotonics. 6 (03), 1 (2019).
  73. Baker, W. B., et al. Pressure modulation algorithm to separate cerebral hemodynamic signals from extracerebral artifacts. Neurophotonics. 2 (3), 35004 (2015).
  74. He, L., et al. Noninvasive continuous optical monitoring of absolute cerebral blood flow in critically ill adults. Neurophotonics. 5 (04), 1 (2018).
  75. Milej, D., et al. Quantification of cerebral blood flow in adults by contrast-enhanced near-infrared spectroscopy: Validation against MRI. Journal of Cerebral Blood Flow & Metabolism. , (2019).
  76. Diop, M., Verdecchia, K., Lee, T. Y., St Lawrence, K. Calibration of diffuse correlation spectroscopy with a time-resolved near-infrared technique to yield absolute cerebral blood flow measurements. Biomedical Optics Express. 2 (7), 2068 (2011).
  77. Khalid, M., et al. Development of a stand-alone DCS system for monitoring absolute cerebral blood flow. Biomedical Optics Express. 10 (9), 4607 (2019).
  78. Kohl-Bareis, M., et al. Noninvasive monitoring of cerebral blood flow by a dye bolus method: Separation of brain from skin and skull signals. Journal of Biomedical Optics. 7 (3), 464 (2002).

Tags

Real-time MonitoringNeurocritical PatientsDiffuse Optical SpectroscopiesBrain PhysiologyPortable InstrumentationDiffuse OpticsBlood FlowOxygenationNeuro ICUOptical ProbeCalibration PhantomOptical PropertiesPatient ForeheadLaser Safety GogglesData Acquisition
check_url/kr/61608?article_type=t

Play Video
PDF
DOI
DOWNLOAD MATERIALS LIST
Cite This Article
Menezes Forti, R., Katsurayama, M., Grisotti Martins, G., Valler, L., Quiroga, A., Simioni, L., Menko, J., Falcão, A. L. E., Li, L. M., Mesquita, R. C. Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies. J. Vis. Exp. (165), e61608, doi:10.3791/61608 (2020).
Download Citation
Reprints and Permissions

View Video

✖

To prove you're not a robot, please enter the text in the image below

CAPTCHA Image
Play CAPTCHA Audio
Refresh Image