Noninvasive Raman Monitoring of Urea During Hemodialysis

描述（由申请人提供）：本II期研究项目的目的是开发一种连续、无创、在线过程，用于在血液透析期间光学监测患者血液中的尿素水平。这种过程的最终目标是提供对透析效率的直接和连续的测量，而不必等待抽取血液样品，从而提供对在任何时间点的透析是否已经达到患者的有效停止点同时仍然附接到透析设备的评估。我们建议利用低分辨率激光拉曼散射，通过将患者血液输送至透析器的透析管提供的光学通路，直接测量血液中的尿素水平。我们的I期SBIR结果表明，尿素在动物血液中具有独特的拉曼光谱特征，并且可以在全血背景下识别和定量。我们的II期项目旨在评估拉曼定量测定不同尿素浓度的人血液样本中尿素水平的能力。在构建了一个合适的BUN多元回归模型后，我们将构建一个合适的低分辨率拉曼模块，用于连接到血液透析单元，并将研究扩展到临床环境中实际透析过程中的BUN和URR的人体血液分析。如果成功的话，拉曼测量方法将首次允许实时、直接和连续地监测血液透析过程中尿素去除的进展。这将允许对患者的透析过程进行更有效的定时，以及在患者治疗期间提供透析系统的有效性的持续读出。我们预计，如果第二阶段工作成功，通过对公司现有R-2001拉曼模块的临床设置进行调整，通过光纤探头连接到现有的肾透析设备上，可以快速生产出商业上可行的尿素监测仪。

DESCRIPTION (provided by applicant): It is the aim of the present Phase II research program to develop a continuous, noninvasive, on-line process for optically monitoring the levels of urea in a patient's blood during hemodialysis. The ultimate goal of such a process is to provide a direct and continuous measure of the efficiency of dialysis without having to wait for the drawing of a blood sample, thereby providing an assessment of whether dialysis at any point in time has reached an effective stopping point for the patient while still attached to the dialysis equipment. We propose to utilize low-resolution laser Raman scattering for the direct measurement of the urea levels in blood using the optical access provided by the dialysis tubing delivering the patient's blood to the dialyzer. Our Phase I SBIR results have shown that urea has a unique Raman spectroscopic signature in animal blood and can be identified and quantified against a whole blood background. Our Phase II program is designed to assess the capability of Raman to quantify the levels of urea in human blood samples with varying concentrations of urea present. After constructing a suitable multiple regression model for BUN, we will build out an appropriate low-resolution Raman module for attachment to a hemodialysis unit and expand the investigation to human blood analysis for BUN and URR during actual dialysis procedures in the clinical setting. If successful, a Raman measurement approach would allow, for the first time, real-time, direct and continuous monitoring of the progress of urea removal dudng the course of hemodialysis. This would permit more efficient timing of the dialysis procedure for the patient, as well as providing an ongoing readout of the effectiveness of the dialysis system during patient treatment. We anticipate that a commercially viable urea monitor might be produced rapidly, if the Phase II work is successful, by the adaptation for the clinical setting of the Company's present R-2001 Raman module for attachment by fiberoptic probe to existing renal dialysis equipment.