我们感谢吉智医科大学埼玉医学中心的透析人员和肾脏科的成员。我们要感谢意得辑（www.editage.com）的英文编辑。

所有参与者都提供了书面知情同意书。该研究得到了日本吉智医科大学埼玉医学中心机构审查委员会的批准（RIN 15-104）。
1. 用于监测rSO 2 的装置
<ol><li>准备用于测量组织氧合的近红外光谱设备。该设备有四个通道，可以同时在多达四个器官中进行测量。</li>
	<li>准备一个用于近红外光谱监测的测量传感器，通过发射两个附着波长的近红外光来评估每个器官中的 rSO2 值。</li>
</ol>2. 安装测量传感器
<ol><li>在HD之前，让每位患者仰卧位休息至少5分钟。</li>
	<li>将测量传感器连接到前额、右肋骨和小腿，以分别评估大脑、肝脏和小腿肌肉中的 rSO2 。</li>
	<li>监测脑氧合<ol><li>将测量传感器连接到主半球的前额。</li>
	</ol></li>
	<li>监测肝氧合<ol><li>准备超声检查以测量患者肝脏从体表到肝脏的深度。确认此测量值距离体表在 20–30 毫米以内。接下来，将测量传感器连接到右侧的肋骨。 注意:在本装置中，应在距体表20-30毫米的深层组织中获得rSO2 值。在某些情况下，由于存在厚皮下脂肪，肝脏可能位于距体表30毫米以上的地方。</li>
	</ol></li>
	<li>监测肌肉氧合<ol><li>将测量传感器连接到右侧或双侧小腿。</li>
	</ol></li>
	<li>传感器连接和为设备供电<ol><li>将每个传感器连接到设备的引线。接下来，打开设备，开始测量氧合。</li>
	</ol></li>
</ol>3.穿刺透析分流并开始监测
<ol><li>穿刺透析分流器<ol><li>刺穿患者的透析分流器以开始HD治疗。此时，使用配备透析机的数字血压计测量血压，并使用注射器收集血液样本。</li>
	</ol></li>
	<li>开始监控<ol><li>开始HD治疗后，开始监测三个器官的组织氧合:大脑，肝脏和小腿肌肉。</li>
	</ol></li>
	<li>HD期间监测rSO2<ol><li>观察每个器官的rSO2 值的变化，并定期测量血压，以及HD治疗期间的常规监测，包括心率，静脉压和血容量。确认连接区域以及传感器和引线之间的连接。</li>
	</ol></li>
</ol>

<ol>
	<li>Nishiyama, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+cerebral+oxygen+saturation+monitoring+for+predicting+interventional+outcomes+in+patients+following+out-of-hospital+cardiac+arrest+of+presumed+cardiac+cause:+A+prospective,+observational,+multicentre+study.">Regional cerebral oxygen saturation monitoring for predicting interventional outcomes in patients following out-of-hospital cardiac arrest of presumed cardiac cause: A prospective, observational, multicentre study.</a> Resuscitation. 96, 135-141 (2015).</li><li>Kobayashi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+associated+with+a+low+initial+cerebral+oxygen+saturation+value+in+patients+undergoing+cardiac+surgery.">Factors associated with a low initial cerebral oxygen saturation value in patients undergoing cardiac surgery.</a> Journal of Artificial Organs. 20 (2), 110-116 (2017).</li><li>Cruz, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+multimodal+computational+system+using+near-infrared+spectroscopy+predicts+the+need+for+ECMO+initiation+in+neonates+with+congenital+diaphragmatic+hernia.">A novel multimodal computational system using near-infrared spectroscopy predicts the need for ECMO initiation in neonates with congenital diaphragmatic hernia.</a> Journal of Pediatric Surgery. 53 (1), 152-158 (2018).</li><li>MacEwen, C., Sutherland, S., Daly, J., Pugh, C., Tarassenko, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationship+between+Hypotension+and+Cerebral+Ischemia+during+Hemodialysis.">Relationship between Hypotension and Cerebral Ischemia during Hemodialysis.</a> Journal of the American Socociety of Nephrology. 28 (8), 2511-2520 (2017).</li><li>Polinder-Bos, H. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+cerebral+oxygenation+and+cerebral+blood+flow+during+hemodialysis+-+A+simultaneous+near-infrared+spectroscopy+and+positron+emission+tomography+study.">Changes in cerebral oxygenation and cerebral blood flow during hemodialysis - A simultaneous near-infrared spectroscopy and positron emission tomography study.</a> Journal of Cerebral Blood Flow &amp; Metablism. 40 (2), 328-340 (2020).</li><li>Ookawara, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differences+in+tissue+oxygenation+and+changes+in+total+hemoglobin+signal+strength+in+the+brain,+liver,+and+lower-limb+muscle+during+hemodialysis.">Differences in tissue oxygenation and changes in total hemoglobin signal strength in the brain, liver, and lower-limb muscle during hemodialysis.</a> Journal of Artificial Organs. 21 (1), 86-93 (2018).</li><li>Malik, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+ischemia+worsens+during+hemodialysis+in+end-stage+renal+disease+patients.">Tissue ischemia worsens during hemodialysis in end-stage renal disease patients.</a> The Journal of Vascular Access. 18 (1), 47-51 (2017).</li><li>Ito, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+oxygenation+improvement+is+associated+with+hemoglobin+increase+after+hemodialysis+initiation.">Cerebral oxygenation improvement is associated with hemoglobin increase after hemodialysis initiation.</a> TheInternational Journal of Artificial Organs. , (2020).</li><li>Valerianova, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+responsible+for+cerebral+hypoxia+in+hemodialysis+population.">Factors responsible for cerebral hypoxia in hemodialysis population.</a> Physiological Research. 68 (4), 651-658 (2019).</li><li>Ookawara, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Associations+of+cerebral+oxygenation+with+hemoglobin+levels+evaluated+by+near-infrared+spectroscopy+in+hemodialysis+patients.">Associations of cerebral oxygenation with hemoglobin levels evaluated by near-infrared spectroscopy in hemodialysis patients.</a> PLoS One. 15 (8), 0236720 (2020).</li><li>Kovarova, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+Cerebral+Oxygenation+Is+Associated+with+Cognitive+Impairment+in+Chronic+Hemodialysis+Patients.">Low Cerebral Oxygenation Is Associated with Cognitive Impairment in Chronic Hemodialysis Patients.</a> Nephron. 139 (2), 113-119 (2018).</li><li>Miyazawa, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+of+cerebral+oxygenation+with+estimated+glomerular+filtration+rate+and+cognitive+function+in+chronic+kidney+disease+patients+without+dialysis+therapy.">Association of cerebral oxygenation with estimated glomerular filtration rate and cognitive function in chronic kidney disease patients without dialysis therapy.</a> PLoS One. 13 (6), 0199366 (2018).</li><li>Locatelli, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Haemodialysis+with+on-line+monitoring+equipment:+tools+or+toys.">Haemodialysis with on-line monitoring equipment: tools or toys.</a> Nephrology Dialysis Transplantation. 20 (1), 22-33 (2005).</li><li>Cordtz, J., Olde, B., Solem, K., Ladefoged, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Central+venous+oxygen+saturation+and+thoracic+admittance+during+dialysis:+new+approaches+to+hemodynamic+monitoring.">Central venous oxygen saturation and thoracic admittance during dialysis: new approaches to hemodynamic monitoring.</a> Hemodialysis International. 12 (3), 369-377 (2008).</li><li>Kamijo, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+monitoring+of+blood+pressure+by+analyzing+the+blood+flow+sound+of+arteriovenous+fistula+in+hemodialysis+patients.">Continuous monitoring of blood pressure by analyzing the blood flow sound of arteriovenous fistula in hemodialysis patients.</a> Clinical and Experimental Nephrology. 22 (3), 677-683 (2018).</li><li>Ito, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+affecting+cerebral+oxygenation+in+hemodialysis+patients:+cerebral+oxygenation+associates+with+pH,+hemodialysis+duration,+serum+albumin+concentration,+and+diabetes+mellitus.">Factors affecting cerebral oxygenation in hemodialysis patients: cerebral oxygenation associates with pH, hemodialysis duration, serum albumin concentration, and diabetes mellitus.</a> PLoS One. 10 (2), 0117474 (2015).</li><li>Imai, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deterioration+of+Hepatic+Oxygenation+Precedes+an+Onset+of+Intradialytic+Hypotension+with+Little+Change+in+Blood+Volume+during+Hemodialysis.">Deterioration of Hepatic Oxygenation Precedes an Onset of Intradialytic Hypotension with Little Change in Blood Volume during Hemodialysis.</a> Blood Purification. 45 (4), 345-346 (2018).</li><li>Cho, A. R., Kwon, J. Y., Kim, C., Hong, J. M., Kang, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+sensor+location+on+regional+cerebral+oxygen+saturation+measured+by+INVOS+5100+in+on-pump+cardiac+surgery.">Effect of sensor location on regional cerebral oxygen saturation measured by INVOS 5100 in on-pump cardiac surgery.</a> Journal of Anesthesia. 31 (2), 178-184 (2017).</li><li>Ito, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deterioration+of+cerebral+oxygenation+by+aortic+arch+calcification+progression+in+patients+undergoing+hemodialysis:+A+cross-sectional+study.">Deterioration of cerebral oxygenation by aortic arch calcification progression in patients undergoing hemodialysis: A cross-sectional study.</a> BioMed Research International. , 2852514 (2017).</li><li>Ito, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+transfusion+during+haemodialysis+improves+systemic+tissue+oxygenation:+A+case+report.">Blood transfusion during haemodialysis improves systemic tissue oxygenation: A case report.</a> Nefrologia. 37 (4), 435-437 (2017).</li><li>Ito, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvement+of+bilateral+lower-limb+muscle+oxygenation+by+low-density+lipoprotein+apheresis+in+a+patient+with+peripheral+artery+disease+undergoing+hemodialysis.">Improvement of bilateral lower-limb muscle oxygenation by low-density lipoprotein apheresis in a patient with peripheral artery disease undergoing hemodialysis.</a> Nefrologia. 39 (1), 90-92 (2019).</li><li>Kitano, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+tissue+oxygenation+in+response+to+sudden+intradialytic+hypotension.">Changes in tissue oxygenation in response to sudden intradialytic hypotension.</a> Journal of Artificial Organs. 23 (2), 187-190 (2020).</li><li>Lemmers, P. M. A., Toet, M. C., van Bel, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+patent+ductus+arteriosus+and+subsequent+therapy+with+indomethacin+on+cerebral+oxygenation+in+preterm+infants.">Impact of patent ductus arteriosus and subsequent therapy with indomethacin on cerebral oxygenation in preterm infants.</a> Pediatrics. 121, 142-147 (2008).</li><li>Ito, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sleep+apnea+syndrome+caused+lowering+of+cerebral+oxygenation+in+a+hemodialysis+patient:+a+case+report+and+literature+review.">Sleep apnea syndrome caused lowering of cerebral oxygenation in a hemodialysis patient: a case report and literature review.</a> Renal Replacement Therapy. 4, 54 (2018).</li><li>Minato, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+monitoring+of+changes+in+cerebral+oxygenation+during+hemodialysis+in+a+patient+with+acute+congestive+heart+failure.">Continuous monitoring of changes in cerebral oxygenation during hemodialysis in a patient with acute congestive heart failure.</a> Journal of Artificial Organs. , (2019).</li></ol>

无利益冲突。

近红外光谱监测主要用于评估脑rSO2，特别是在需要体外循环的心脑血管手术中。在包括亨廷顿舞蹈症治疗在内的体外循环中，一些器官可能显示相对缺血7，17，18;然而，目前尚不清楚组织氧合是否变得低。亨廷顿舞蹈症期间的肌肉痉挛或腹痛可能是透析内器官灌注不足引起的低灌注前驱症状之一。然而，在HD治疗中，?...

近红外光谱（NIRS）已被用于评估区域氧饱和度（rSO 2），这是组织氧合的标志物，特别是在各种临床环境中的脑氧合1，2，3，最近已应用于接受血液透析（HD）的患者4，5，6，7，8，9，10，11. 据报道，脑 rSO2 与亨廷顿舞蹈症患者或非透析慢性肾脏病 （CKD） 患者的认知功能有关11，12。然而，到目前为止，近红外光谱监测在CKD患者中的使用受到限制。
由于近红外光谱监测是实时和非侵入性的，我们评估了其作为HD患者监测设备的实用性。虽然近红外光谱主要用于测量大脑rSO 2，但我们也研究了HD期间其他器官的rSO2值。 具体来说，将rSO 2测量传感器连接到前额，右肋骨和小腿，以分别评估大脑，肝脏和下肌肉中的rSO2。结果表明，近红外监测可能是阐明HD患者器官氧合变化或影响CKD患者组织氧合的因素的新方法。
迄今为止，在临床环境中，在HD，血容量监测，中心静脉血氧饱和度，胸廓入院和电子听诊器引导的估计血压（BP）期间进行了连续监测13，14，15;然而，低血压的预测或设备的广泛使用存在局限性。相比之下，这里的新无创方法可以提供单个器官中透析内氧动力学的实时信息。因此，这种监测方法可以允许在透析内低血压的早期阶段检测短暂的器官缺血，也可以允许HD的安全表现。本文描述了一种测量以rSO2为代表的组织氧合的方案，应用于HD患者。

<table><tbody><tr><td>DBB-100NX</td><td>Nikkiso</td><td>DBB-100NX</td><td>Dialysis machine</td></tr><tr><td>INVOS 5100c</td><td>Covidien Japan</td><td>INVOSTM 5100c</td><td>tissue oxygenation device</td></tr><tr><td>SOMASENSER</td><td>Covidien Japan</td><td>CV-SAFB-SM/INTL</td><td>NIRS sensor</td></tr></tbody></table>

measurement of tissue oxygenation using near-infrared spectroscopy in patients undergoing hemodialysis

近红外光谱（NIRS）最近已被用作测量区域氧饱和度（rSO2）的工具，这是组织氧合的标志物，用于心血管和脑外科手术，新生儿监测和院前医学等临床环境。近红外光谱监测设备是实时和非侵入性的，主要用于评估危重患者在手术或重症监护期间的脑氧合。到目前为止，包括血液透析（HD）在内的慢性肾脏病（CKD）患者使用近红外光谱监测是有限的;因此，我们研究了HD期间某些器官的rSO2 值。我们使用近红外光谱设备以2个附着波长发射近红外光，监测rSO2 值。HD患者仰卧位，将rSO2 测量传感器分别连接到额头、右肋骨和小腿，以评估大脑、肝脏和小腿肌肉中的rSO2 。近红外光谱监测可能是阐明HD患者器官氧合变化或影响CKD患者组织氧合的因素的新方法。本文描述了一种测量以rSO2 为代表的组织氧合的方案，应用于HD患者。

HD前脑rSO 2值低于健康受试者，HD糖尿病（DM）患者脑rSO2低于无DMHD患者（图1）16。此外，尽管HD期间组织氧合继续且血压没有降低，但我们偶然观察到由于透析内低血压引起的脑和肝脏rSO 2的变化（图2）。由于连续监测，组织氧合的变化比间歇监测血压更快。 数据表示为标准误差±平均值。非配对值的方差分析?...

Watch this Scientific Journal Video about Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis at JoVE.com

Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis

我们提出了一种通过使用近红外光谱监测仪测量血液透析（HD）患者区域氧饱和度（rSO2）的方案。rSO2 值是组织氧合的指标。这种无创和实时监测可能有助于确认HD期间器官氧合的变化。

使用近红外光谱测量血液透析患者的组织氧合

Near-infrared spectroscopy (NIRS) has recently been applied as a tool to measure regional oxygen saturation (rSO2), a marker of tissue oxygenation, in ...

measurement-tissue-oxygenation-using-near-infrared-spectroscopy

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

2.1K 次观看.  Jichi Medical University. 我们提出了一种通过使用近红外光谱监测仪测量血液透析（HD）患者区域氧饱和度（rSO2）的方案。rSO2 值是组织氧合的指标。这种无创和实时监测可能有助于确认HD期间器官氧合的变化。

视频: Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis

Dual-mode Imaging of Cutaneous Tissue Oxygenation and Vascular Function

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health disorders such as chronic wounds. We report the development of a dual-mode imaging system for non-invasive and non-contact imaging of cutaneous tissue oxygenation and vascular function. The imaging system integrated an infrared camera, a CCD camera, a liquid crystal tunable filter and a high intensity fiber light source. A Labview interface was programmed for equipment control, synchronization, image acquisition, processing, and visualization. Multispectral images captured by the CCD camera were used to reconstruct the tissue oxygenation map. Dynamic thermographic images captured by the infrared camera were used to reconstruct the vascular function map. Cutaneous tissue oxygenation and vascular function images were co-registered through fiduciary markers. The performance characteristics of the dual-mode image system were tested in humans.

A dual-mode imaging system was developed for non-contact assessment of cutaneous tissue oxygenation and vascular function.

双模式成像，皮肤组织氧合和血管功能

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health ...

科研

医学

Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants

Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO2). Thus, measures of CMRO2 are reflective of neuronal viability and provide critical diagnostic information, making CMRO2 an ideal target for bedside measurement of brain health.
Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases.
Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO2) as a surrogate for cerebral oxygen consumption. However, SO2 is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO2 are not sensitive enough to detect brain injury hours after the insult 1,2, because oxygen consumption and delivery reach equilibrium after acute transients 3. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO2 (CMRO2i) 4,5.
With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain development, and response to therapy in neonates. Moreover, this method adheres to all neonatal intensive care unit (NICU) policies on infection control and institutional policies on laser safety. Future work will seek to integrate the two instruments to reduce acquisition time at the bedside and to implement real-time feedback on data quality to reduce the rate of data rejection.

We combined frequency-domain near-infrared spectroscopy measures of cerebral hemoglobin oxygenation with diffuse correlation spectroscopy measures of cerebral blood flow index to estimate an index of oxygen metabolism. We tested the utility of this measure as a bedside screening tool to evaluate the health and development of the newborn brain.

婴幼儿的脑代谢和血流动力学的非侵入式光学测量

Perinatal brain injury remains a significant cause of infant mortality  and morbidity, but there is not yet an effective bedside tool that can  accurately ...

A Model to Simulate Clinically Relevant Hypoxia in Humans

In case of apnea, arterial partial pressure of oxygen (pO2) decreases, while partial pressure of carbon dioxide (pCO2) increases. To avoid damage to hypoxia sensitive organs such as the brain, compensatory circulatory mechanisms help to maintain an adequate oxygen supply. This is mainly achieved by increased cerebral blood flow. Intermittent hypoxia is a commonly seen phenomenon in patients with obstructive sleep apnea. Acute airway obstruction can also result in hypoxia and hypercapnia. Until now, no adequate model has been established to simulate these dynamics in humans. Previous investigations focusing on human hypoxia used inhaled hypoxic gas mixtures. However, the resulting hypoxia was combined with hyperventilation and is therefore more representative of high altitude environments than of apnea. Furthermore, the transferability of previously performed animal experiments to humans is limited and the pathophysiological background of apnea induced physiological changes is poorly understood. In this study, healthy human apneic divers were utilized to mimic clinically relevant hypoxia and hypercapnia during apnea. Additionally, pulse-oximetry and Near Infrared Spectroscopy (NIRS) were used to evaluate changes in cerebral and peripheral oxygen saturation before, during, and after apnea.

Hypoxia simulation in humans has usually been performed by inhaling hypoxic gas mixtures. For this study, apneic divers were used to simulate dynamic hypoxia in humans. Additionally, physiological changes in desaturation and re-saturation kinetics were evaluated with non-invasive tools such as Near-Infrared-Spectroscopy (NIRS) and peripheral oxygenation saturation (SpO2).

一个模型来模拟人类临床相关性缺氧

In case of apnea, arterial partial pressure of oxygen (pO2) decreases, while partial pressure of carbon dioxide (pCO2) increases. To avoid damage to ...

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic demand. Reactive hyperemia (in response to a brief period of tissue ischemia) is an independent predictor of cardiovascular events and provides important insight into vascular health and vasodilatory capacity. Skeletal muscle oxidative capacity is equally important in health and disease, as it determines the energy supply for myocellular processes. Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess each of these major clinical endpoints (reactive hyperemia, neurovascular coupling, and muscle oxidative capacity) during a single clinic or laboratory visit. Unlike Doppler ultrasound, magnetic resonance images/spectroscopy, or invasive catheter-based flow measurements or muscle biopsies, our approach is less operator-dependent, low-cost, and completely non-invasive. Representative data from our lab taken together with summary data from previously published literature illustrate the utility of each of these end-points. Once this technique is mastered, application to clinical populations will provide important mechanistic insight into exercise intolerance and cardiovascular dysfunction.

Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess reactive hyperemia, neurovascular coupling and skeletal muscle oxidative capacity in a single clinic or laboratory visit.

"一站式" 近红外光谱对骨骼肌神经血管的耦合、氧化能力及微血管功能的作用

Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic ...

Cerebrovascular Reactivity Measurement with Functional Near Infrared Spectroscopy

Cerebrovascular reactivity (CVR) is the capacity of blood vessels in the brain to alter cerebral blood flow (either with dilation or constriction) in response to chemical or physical stimuli. The amount of reactivity in the cerebral microvasculature depends on the integrity of the capacitance vasculature and is the primary function of endothelial cells. CVR is, therefore, an indicator of the microvasculature&#8217;s physiology and overall health. Imaging methods that can measure CVR are available but can be costly, and require magnetic resonance imaging centers and technical expertise. In this study, we used fNIRS technology to monitor changes of oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) in the cerebral microvasculature to assess the CVR of 15 healthy controls (HC) in response to a vasoactive stimulus (inhaled 5% carbon dioxide or CO2). Our results suggest that this is a promising imaging technology that offers a non-invasive, accurate, portable, and cost-effective method of mapping cortical CVR and associated microvasculature function, resulting from a traumatic brain injury or other conditions associated with cerebral microvasculopathy.

Presented here is a protocol for imaging and measurement of cerebrovascular reactivity in humans with functional Near Infrared Spectroscopy (fNIRS). fNIRS is a novel imaging modality that captures the concentration changes of hemoglobin species in the brain&#8217;s outermost cortex under specific stimuli.

Cerebrovascular reactivity (CVR) is the capacity of blood vessels in the brain to alter cerebral blood flow (either with dilation or constriction) in ...

神经科学

Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure

Cerebral hypo-oxygenation during rest or exercise negatively impacts the exercise capacity of patients with heart failure with reduced ejection fraction (HF). However, in clinical cardiopulmonary exercise testing (CPET), cerebral hemodynamics is not assessed. NIRS is used to measure cerebral tissue oxygen saturation (SctO2) in the frontal lobe. This method is reliable and valid and has been utilized in several studies. SctO2 is lower during both rest and peak exercise in patients with HF than in healthy controls (66.3 &#177; 13.3% and 63.4 &#177; 13.8% vs. 73.1 &#177; 2.8% and 72 &#177; 3.2%). SctO2 at rest is significantly linearly correlated with peak VO2 (r = 0.602), oxygen uptake efficiency slope (r = 0.501), and brain natriuretic peptide (r = -0.492), all of which are recognized prognostic and disease severity markers, indicating its potential prognostic value. SctO2 is determined mainly by end-tidal CO2 pressure, mean arterial pressure, and hemoglobin in the HF population. This article demonstrates a protocol that integrates SctO2 using NIRS into incremental CPET on a calibrated bicycle ergometer.

This protocol integrated near-infrared spectroscopy into conventional cardiopulmonary exercise testing to identify the involvement of the cerebral hemodynamic response in exercise intolerance in patients with heart failure.

心力衰竭患者心肺运动测试中脑组织饱和监测的集成

Cerebral hypo-oxygenation during rest or exercise negatively impacts the exercise capacity of patients with heart failure with reduced ejection fraction ...

How to Administer Near-Infrared Spectroscopy in Critically ill Neonates, Infants, and Children

Near infrared spectroscopy (NIRS) calculates regional tissue oxygenation (rSO2) using the different absorption spectra of oxygenated and deoxygenated hemoglobin molecules. A probe placed on the skin emits light that is absorbed, scattered, and reflected by the underlying tissue. Detectors in the probe sense the amount of reflected light: this reflects the organ-specific ratio of oxygen supply and consumption - independent of pulsatile flow. Modern devices enable the simultaneous monitoring at different body sites. A rise or dip in the rSO2 curve visualizes changes in oxygen supply or demand before vital signs indicate them. The evolution of rSO2 values in relation to the starting point is more important for interpretation than are absolute values.
A routine clinical application of NIRS is the surveillance of somatic and cerebral oxygenation during and after cardiac surgery. It is also administered in preterm infants at risk for necrotizing enterocolitis, newborns with hypoxic ischemic encephalopathy and a potential risk of impaired tissue oxygenation. In the future, NIRS could be increasingly used in multimodal neuromonitoring, or applied to monitor patients with other conditions (e.g., after resuscitation or traumatic brain injury).

This protocol is designed to assist clinicians to measure regional tissue oxygenation at different body sites in infants and children. It can be used in situations where tissue oxygenation is potentially compromised, particularly during cardiopulmonary bypass, when using non-pulsatile cardiac-assist devices, and in critically ill neonates, infants and children.

如何管理危重新生儿、婴儿和儿童近红外光谱

Near infrared spectroscopy (NIRS) calculates regional tissue oxygenation (rSO2) using the different absorption spectra of oxygenated and deoxygenated ...

Non-Invasive Monitoring of Microvascular Oxygenation and Reactive Hyperemia using Hybrid, Near-Infrared Diffuse Optical Spectroscopy for Critical Care

The detection of levels of impairment in microvascular oxygen consumption and reactive hyperemia is vital in critical care. However, there are no practical means for a robust and quantitative evaluation. This paper describes a protocol to evaluate these impairments using a hybrid near-infrared diffuse optical device. The device contains modules for near-infrared time-resolved and diffuse correlation spectroscopies and pulse-oximetry. These modules allow the non-invasive, continuous, and real-time measurement of the absolute, microvascular blood/tissue oxygen saturation (StO2) and the blood flow index (BFI) along with the peripheral arterial oxygen saturation (SpO2). This device uses an integrated, computer-controlled tourniquet system to execute a standardized protocol with optical data acquisition from the brachioradialis muscle. The standardized vascular occlusion test (VOT) takes care of the variations in the occlusion duration and pressure reported in the literature, while the automation minimizes inter-operator differences. The protocol we describe focuses on a 3-min occlusion period but the details described in this paper can readily be adapted to other durations and cuff pressures, as well as other muscles. The inclusion of an extended baseline and post-occlusion recovery period measurement allows the quantification of the baseline values for all the parameters and the blood/tissue deoxygenation rate that corresponds to the metabolic rate of oxygen consumption. Once the cuff is released, we characterize the tissue reoxygenation rate, magnitude, and duration of the hyperemic response in BFI and StO2. These latter parameters correspond to the quantification of the reactive hyperemia, which provides information about the endothelial function. Furthermore, the above-mentioned measurements of the absolute concentration of oxygenated and deoxygenated hemoglobin, BFI, the derived metabolic rate of oxygen consumption, StO2, and SpO2 provide a yet-to-be-explored rich data set that can exhibit disease severity, personalized therapeutics, and management interventions.

We describe a protocol to non-invasively and continuously measure absolute microvascular blood flow index and blood oxygen saturation using a multi-modal device based on near-infrared diffuse optics. We then evaluate the metabolic rate of oxygen consumption and reactive hyperemia utilizing a vascular occlusion test.

使用混合近红外漫反射光谱对重症监护的微血管氧合和反应性充血进行无创监测

The detection of levels of impairment in microvascular oxygen consumption and reactive hyperemia is vital in critical care. However, there are no ...

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise

The gold standard to assess the aerobic capacity in physically active subjects and athletes is the maximal oxygen consumption test (VO2&#8211;max), which involves analysis of exhaled&#8211;gases and cardiorespiratory variables obtained via the breath-by-breath method in an ergospirometer during an incremental exercise. However, this method cannot elucidate metabolic changes at the muscular level. Near-infrared spectroscopy (NIRS) has emerged as a valuable technology to evaluate local oxygen levels (Tissular Saturation Index, TSI) by quantifying the concentrations of oxygenated (O2-Hb) and deoxygenated (H-Hb) hemoglobin in the microvasculature of tissues. NIRS applications extend to respiratory and locomotor muscles, assessing metabolic changes associated with the cost of breathing (COB) and peripheral workload, respectively. Additionally, cerebral regions, such as the prefrontal cortex, have been explored with NIRS technology to assess physiological changes related to cognitive demand associated with planning or ideation of motor tasks linked to sports performance. Thus, by analyzing exercise-induced changes (D) in O2-Hb, H-Hb, and TSI, it is possible to identify central and peripheral exercise limitations, particularly when endurance training is the main component of physical fitness (e.g., running, cycling, triathlon, etc.). Addressing these factors is paramount for coaches and exercise physiologists to optimize athletic performance, incorporating training strategies focused on the primary exercise-limiting factors. This study outlines a protocol for utilizing wearables devices equipped with NIRS technology to analyze exercise changes in TSI, O2-Hb, and H-Hb, alongside cardiorespiratory variables typically registered in athletes during VO2&#8211;max tests. This approach offers a comprehensive method for identifying the primary systems involved in stopping exercise progression and sports performance improvement.

This protocol integrates near-infrared spectroscopy (NIRS) technology to assess localized hematological and oxygenation changes at the prefrontal cortex, respiratory (m.Intercostales), and locomotor (m.Vastus Lateralis) muscles during cardiopulmonary exercise testing, enabling the identification of central and peripheral limiting factors affecting exercise performance.

使用近红外光谱可穿戴设备识别运动期间的中枢限制与外周限制

The gold standard to assess the aerobic capacity in physically active subjects and athletes is the maximal oxygen consumption test (VO2&#8211;max), which ...

优化 NIRS 以评估下肢血管功能

Near-Infrared Spectroscopy During Reactive Hyperemia for the Assessment of Lower Limb Vascular Function

Vascular diseases of the lower limb contribute substantially to the&#160;global burden of cardiovascular disease and comorbidities such as diabetes. Importantly, microvascular dysfunction can occur prior to, or alongside, macrovascular pathology, and both potentially contribute to patient symptoms and disease burden. Here, we describe a non-invasive approach using near-infrared spectroscopy (NIRS) during reactive hyperemia, which provides a standardized assessment of lower limb vascular (dys)function and a potential method to evaluate the efficacy of therapeutic interventions. Unlike alternative methods, such as contrast-enhanced ultrasound, this approach does not require venous access or sophisticated image analysis, and it is inexpensive and less operator-dependent. This description of the NIRS method includes representative results and standard terminology alongside the discussion of measurement considerations, limitations, and alternative methods. Future application of this work will improve standardization of vascular research design, data collection procedures, and harmonized reporting, thereby enhancing translational research outcomes in the areas of lower limb vascular (dys)function, disease, and treatment.

作者聚焦：通过新型干预措施和 NIRS 技术增强心血管疾病的血管功能和体能

Here, we describe a non-invasive approach using near-infrared spectroscopy to assess reactive hyperemia in the lower limb. This protocol provides a standardized assessment of vascular and microvascular responsiveness that may be used to determine the presence of vascular dysfunction as well as the efficacy of therapeutic interventions.

反应性充血期间的近红外光谱评估下肢血管功能 

Vascular diseases of the lower limb contribute substantially to the&#160;global burden of cardiovascular disease and comorbidities such as diabetes. ...