Noninvasive Raman Monitoring of Urea During Hemodialysis

描述(由申请人提供)：目前的第二阶段研究计划的目标是开发一种连续的、非侵入性的、在线的过程，用于光学监测血液透析期间患者血液中的尿素水平。这一过程的最终目的是提供对透析效率的直接和连续的测量，而不必等待抽取血样，从而评估在任何时间点的透析是否已经达到患者的有效停止点，同时仍然连接到透析设备。我们建议利用低分辨率激光拉曼散射直接测量血液中的尿素水平，利用透析管提供的光学通道将患者的血液输送到透析器。我们的第一相SBIR结果表明，尿素在动物血液中具有独特的拉曼光谱特征，可以在全血背景下进行识别和定量。我们的第二阶段计划旨在评估拉曼光谱在存在不同浓度尿素的情况下定量测定人体血液样本中尿素水平的能力。在构建合适的BUN多元回归模型后，我们将构建适用于血液透析装置的合适的低分辨率拉曼模块，并将研究扩展到临床上实际透析过程中对BUN和URR的血液分析。如果成功，拉曼测量方法将首次能够实时、直接和连续地监测血液透析过程中尿素的清除进度。这将允许对患者的透析程序进行更有效的计时，并在患者治疗期间提供对透析系统的有效性的持续读数。我们预计，如果第二阶段的工作成功，通过调整公司目前的R-2001拉曼模块的临床环境，通过光纤探头将其连接到现有的肾脏透析设备上，可以迅速生产出商业上可行的尿素监测器。

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.