Transcutaneous measurement of glucose using Raman spectroscopy

Abstract

Transcutaneous glucose measurement would provide the ability to obtain frequent measurements without the pain and risk of infection associated with obtaining a blood sample and eliminates the need for reagents. Because of these potential benefits, a large effort is being made within the academic and industrial research communities to develop alternative rapid and easily manageable analysis methods, including transcutaneous methods. Several optical techniques have been proposed and investigated widely to replace the traditional method. Transcutaneous measurement would be of particular benefit to the millions of people with diabetes who should monitor glucose levels multiple times per day and today depend on the finger pricking devices. We have used the advantages provided by NIR Raman spectroscopy, i.e. sharp and distinct spectral features combined with a large probe volume, in order to simultaneously quantify multiple analytes (glucose, urea, cholesterol, triglycerides, total protein, albumin, hemoglobin, hematocrit (hct)) in serum and whole blood samples. Based on the successful measurements, we have moved toward transcutaneous measurements of glucose from 16 healthy human subjects as the first target of blood analytes. RMSEP of 13.17 mg/dL and r² values of 0.79 show promise that the Raman spectroscopy can be developed to achieve clinical accuracy requirements. Furthermore, the fact that glucose features could be recognized in the calibration spectra from measurements of volunteers whose glucose levels changed in a relatively large range, provides evidence that the calibration is based upon glucose.