Frequency domain diffuse optical spectroscopy and diffuse correlation spectroscopy for assessing inspiratory muscle metabolism in mechanically ventilated patients

频域漫反射光谱和漫相关光谱用于评估机械通气患者的吸气肌代谢

• 批准号: 10194837
• 负责人: Darren Michael Roblyer
• 金额: $ 21.5万
• 依托单位: BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10194837
• 关键词: Accounting; Address; Algorithms; Benchmarking; Blood flow; Boa; Boston; Breathing; COVID-19; COVID-19 pandemic; Cardiogenic Shock; Clinical; Critical Illness; Custom; Detection; Development; Devices; Diffuse; Disuse Atrophy; Electronics; Expenditure; Failure; Feasibility Studies; Feedback; Frequencies; Functional disorder; Funding; Future; Heart Diseases; Hospital Costs; Inflammation; Lead; Link; Lipids; Lung diseases; Measurement; Measures; Mechanical ventilation; Metabolic; Metabolism; Methodology; Modeling; Monitor; Morbidity - disease rate; Muscle; Optics; Organ; Oxidative Stress; Oxygen; Patients; Performance; Phase; Physicians; Population; Procedures; Property; Research; Respiratory Diaphragm; Respiratory Muscles; Scientist; Septic Shock; Skin; Spectrum Analysis; Speed; Sternocleidomastoid Muscle; System; Techniques; Technology; Testing; Therapeutic; Thick; Time; Tissues; Variant; Ventilator; Weaning; Work; base; computerized data processing; deep neural network; digital; disability; healthy volunteer; human subject; improved; improved outcome; indexing; metabolic rate; mortality; muscle metabolism; muscle physiology; novel; respiratory; septic; subcutaneous; success; technology development; temporal measurement; trend

PROJECT SUMMARY Mechanical ventilation (MV), which is used to assist or replace spontaneous breathing in critically ill patients, led to $27 billion in expenditures in the US in 2010, accounting for 12% of all hospital costs. In that same year there were 2.7 episodes of MV per 1000 population, highlighting the enormous importance of this procedure. The COVID-19 pandemic has substantially increased these numbers, although precise rates are not yet available. MV is used, in part, to “unload”, or reduce the metabolic effort of respiratory muscles in order to redirect oxygen delivery to vital organs. As the patients’ conditions improve, key inspiratory muscles (e.g. diaphragm, scalenes, sternomastoid, etc.) need to take over spontaneous breathing independent of the ventilator. This “reloading” is precarious due to muscle disuse atrophy, induced by unloading. This is further complicated by other common conditions such as septic or cardiogenic shock, which can severely limit oxygen delivery independent of muscle status. What’s needed is a methodology that can continuously monitor blood flow and oxygen utilization of inspiratory muscles so that respiratory effort can be continuously optimized during MV. This project aims to develop a comprehensive blood flow index, oxygenation, and metabolic measurement platform for inspiratory muscle physiology by integrating wideband frequency-domain diffuse optical spectroscopy (wbDOS) and diffuse correlation spectroscopy (DCS) to tackle this unmet need. wbDOS is a new all-digital frequency-domain DOS technique that captures amplitude and phase measurements over a wide bandwidth of modulation frequencies (50-500 MHz) at high speeds (>100 Hz). wbDOS and DCS will combine synergistically to provide pathlength- corrected estimates of absolute Hb/Mb concentrations and blood flow index (BFi), allowing for the extraction of tissue regional oxygen metabolic rate (MRO2i), a parameter directly linked to oxygen utilization. We hypothesize that wbDOS and DCS measurements can be acquired simultaneously at high speed (>10 Hz) with parallel detection and integrated electronics. This speed is needed to capture inspiratory/expiratory dynamics at the respiratory rate. Additionally, we hypothesize wideband frequency-domain DOS measurements will provide improved quantification of optical properties, BFi and MRO2i when optically integrated with DCS as compared to single frequency FD-DOS or CW-NIRS. We will validate this through rigorous system testing using flow-channel tissue-mimicking optical phantoms. A multi-layer inverse model will be developed to better capture inspiratory muscle metabolism by accounting for subcutaneous lipid thickness and skin tones. We will also expand on our recent work in Deep Neural Network (DNN) processing to develop high-speed algorithms for calculating Hb/Mb concentrations, StO2 (%), BFi (mm2/s), and MRO2i at 10 Hz. We will conduct a feasibility study (n=10) of healthy volunteers during respiratory muscle loading and unloading to evaluate performance compared to expected trends. It is anticipated that completion of these aims will yield a novel and comprehensive blood flow index, oxygenation, and metabolic measurement platform (wbDOS-DCS) and lead to subsequent R01-scale funding.

项目摘要 机械通气（MV）用于协助或替代重症患者的赞助呼吸 2010年在美国的270亿美元支出占所有医院费用的12％。同年 是每1000个人口的MV 2.7次发作，强调了此程序的巨大重要性。 Covid-19大流行大大增加了这些数字，尽管尚未确切的速度。 MV部分用于“卸载”或减少呼吸肌肉的代谢努力以重定向氧气 交付至重要器官。随着患者状况的改善，关键的励志肌肉（例如，隔膜，鳞片，， 胸骨类药物等）需要接管独立于呼吸机的赞助呼吸。这种“重新加载”是 由于卸载引起的肌肉萎缩而导致的不稳定。这是其他常见的更复杂的 败血症或心源性休克等疾病，它们可以严重限制氧气递送独立于肌肉 地位。需要的方法是可以连续监测血流和氧气利用的方法 吸气肌肉，以便在MV期间可以连续优化呼吸系统。这个项目旨在 为灵感发展开发全面的血流指数，氧合和代谢测量平台 通过整合宽带频率域弥漫性光谱（WBDOS）和弥漫性来通过肌肉生理 相关光谱（DC）以应对这种未满足的需求。 WBDOS是一种新的全数字频域DOS 在调制频率的宽带宽度上捕获放大器和相测量的技术 （50-500 MHz）高速（> 100 Hz）。 WBDOS和DCS将结合协同结合以提供路径长度 - 对绝对HB/MB浓度和血流指数（BFI）的校正估计值，允许提取 组织区域氧代谢率（MRO2I），这是与氧利用直接相关的参数。我们假设 WBDOS和DCS测量可以与平行的高速（> 10 Hz）获取 检测和集成电子设备。需要此速度以捕获灵感/呼气动态 呼吸率。此外，我们假设宽带频域DOS测量将提供 与DC光学整合时，相比 单频FD-DOS或CW-NIR。我们将通过使用流通道进行严格的系统测试来验证这一点 模拟组织的光学幻像。将开发多层逆模型以更好地捕捉灵感 通过考虑皮下脂质厚度和肤色的肌肉代谢。我们还将扩大我们的 深度神经网络（DNN）处理的最新工作，以开发用于计算HB/MB的高速算法 浓度为sto2（％），BFI（MM2/s）和MRO2I，为10 Hz。我们将进行健康的可行性研究（n = 10） 与预期相比 趋势。预计这些目标的完成将产生一种新颖而全面的血流指数， 氧合和代谢测量平台（WBDOS-DC），并导致随后的R01尺度资金。