NSF/FDA SiR: Pulse Oximetry Measurement Errors Correlated with Patient Skin Pigmentation: Optical Mechanisms and Effect Multipliers

脉搏血氧仪是一种功能强大且价格低廉的设备，通常用于早期检测健康问题和监测治疗。然而，研究表明，患者的皮肤色素沉着水平会影响测量精度。更好地理解潜在的机制将有助于改进仪器和算法，以提高器件性能。计算建模将用于模拟成人手指组织中的光传播，并研究不同生物学和器械设计因素对器械性能的影响。将进行组织模拟模型的实验室测量，以在良好控制的条件下验证计算模型。对器械性能的这种有效、最小负担的评价有可能导致临床性能的改善，从而影响接受外科手术、麻醉和其他危急情况的患者。此外，计划中的研究将与教育，指导和推广活动无缝集成，以推进生物医学光学和监管科学领域的跨学科计划。本计画旨在发展及验证一系列脉搏血氧饱和度的测试方法。这项工作的组成部分包括：（1）制造具有成人手指生物学相关特性的物理模型（例如，具有不同色素沉着水平的表皮层、仿生微血管网络和具有可调氧合以生成实时生理流量/压力波形的模拟心血管流量回路）;（2）开发不同尺寸的成人手指的计算机模型并执行Monte Carlo模拟以阐明脉搏血氧仪中的光-组织相互作用;以及（3）在模拟手指的物理模型中使用光谱测量来验证计算模型，并且研究表皮黑色素含量沿着其它生物因素（例如，灌注水平，手指尺寸）和设备特性（例如，源带宽、传感器反射率）对关键光-组织相互作用参数以及对估计的氧饱和度测量精度的影响。该项目将为影响脉搏血氧定量准确性的因素提供广泛的见解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Pulse oximeters are powerful and inexpensive devices commonly used for early detection of health problems and monitoring of treatment. However, studies have shown that patient skin pigmentation levels can affect the measurement accuracy. A better understanding of the underlying mechanisms will help the refinement of instrumentation and algorithms to improve the device performance. Computational modeling will be used to simulate light propagation in adult finger tissue and investigate the impact of different biological and device design factors on device performance. Laboratory measurements of tissue-mimicking models will be performed to validate the computational model under well-controlled conditions. Such effective, least-burdensome evaluation of device performance has the potential to lead to improvements in clinical performance that will impact patients undergoing surgical procedures, anesthesia, and other critical conditions. Furthermore, the planned research will be seamlessly integrated with educational, mentoring, and outreach activities to advance the cross-disciplinary program in the field of Biomedical Optics and Regulatory Sciences. This project aims to develop and validate a series of test methods for pulse oximetry. The components of this work include: (1) Fabricating physical models with biologically relevant properties of adult fingers (e.g., epidermal layers with different pigmentation levels, bio-mimetic microvascular networks, and mock cardiovascular flow loop with tunable oxygenation to generate real-time physiological flow/pressure waveforms); (2) Developing in silico models of adult fingers of different sizes and performing Monte Carlo simulations to elucidate light-tissue interactions in pulse oximetry; and (3) Validating computational models using spectroscopic measurements in finger-simulating physical models, and investigating effects of epidermal melanin content along with other biological factors (e.g., perfusion level, finger size) and device characteristics (e.g., source bandwidth, sensor reflectivity) on key light-tissue interaction parameters, as well as on estimated oxygen saturation measurement accuracy. This project will provide extensive insights into the factors influencing quantitative accuracy of pulse oximetry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.