Raman spectroscopic monitoring of hemodialysis

Abstract

Spectroscopic systems and methods are disclosed for determining levels of at least one analyte in blood undergoing hemodialysis. In one aspect, the invention employs Raman spectroscopy to monitor and / or control hemodialysis. In one embodiment, the system uses a laser light directed to circulating blood from a patient undergoing dialysis to make Raman spectral measurements. For example, the laser light can be directed into a segment of the dialysis tubing. The system can utilize unique Raman spectroscopic signature of one or more analytes, e.g., urea, to identify and quantify such analytes against a whole blood background. Based on the spectral response, the concentration of the analytes can be monitored and / or used to control hemodialysis.

Description

FIELD OF THE INVENTION[0001]The technical field of this invention relates to methods for monitoring analyte levels in blood by Raman spectroscopy systems. More particularly, it relates to methods for monitoring urea levels in blood while a patient is undergoing hemodialysis by using Raman spectroscopy systems.BACKGROUND OF THE INVENTION[0002]When protein is broken down in the body, urea is produced as one of the waste products. Normally, urea is removed from the body by the kidneys and excreted as urine. However, during kidney impairment or failure, urea builds up in the body and particularly in the blood.[0003]When kidneys fail, dialysis is necessary to remove waste products such as urea from the blood. Urea is not very toxic by itself, but its level represents the levels of many other waste products that build up in the blood when the kidneys fail. The need for a patient to undergo dialysis particularly becomes acute in end stage renal disease (ESRD). ERSD causes people to experie...

AI Technical Summary

Benefits of technology

[0010]The present invention provides methods for continuous monitoring the level of urea (and / or other analytes) in blood undergoing hemodialysis. Such methods can provide direct, continuous URR and / or Kt / V measurements while the patient is still attached to the hemodialysis equipment. Moreover the methods of the present invention can, in at least some instances, reduce the time a patient has to spend to undergo hemodialysis. The invention employs spectroscopic analysis, preferably low resolution Raman spectroscopy, to monitor and / or control hemodialysis.

Problems solved by technology

However, during kidney impairment or failure, urea builds up in the body and particularly in the blood.

However, both the URR and Kt / V techniques currently employed assessments of hemodialysis efficiency of treatment are point measurements, often not even performed at every dialysis treatment, that do not allow continuous evaluation of effectiveness.

Both require blood sampling before and after treatment and require time consuming chemical analyses.

As a consequence, the measurements cannot be used to determine actual urea clearance efficiency or control the extent and duration of an individual patient's dialysis session.

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