Neonatal Bilirubinometer for Near-Patient Testing

Steinke, John

Abstract

The goal of this project is to develop a portable instrument for measuring the total bilirubin concentration in blood samples from neonates. Although other products are available for this purpose, the turn-around time between obtaining a blood sample and receiving results from a central clinical laboratory often impairs the pediatrician's management of healthy and hyperbilirubinemic neonates, and can delay the discharge of mother and child from the hospital, unnecessarily increasing healthcare costs. Furthermore, the conventional benchtop bilirubinometers that are sometimes used in newborn nurseries, neonatal intensive care units, and pediatricians' offices require extensive sample preparation, including the centrifugation of potentially infectious blood samples. By contrast, the goal of this project is to develop a portable bilirubinometer specifically for near-patient testing. To compete successfully with conventional instruments, the new bilirubinometer should (1) be portable, safe, accurate, and relatively inexpensive, (2) be operated easily by non-laboratory personnel, (3) not require centrifugation or extensive sample preparation, (4) use a small volume of blood (10-100 microliters), and (5), analyze the sample quickly, that is, in less that ten seconds. In Phase I, the investigators will evaluate three candidate measurement systems for precision, accuracy, speed, and ease of use. The first approach to be evaluated is spectrophotometrically measuring total bilirubin in unaltered whole blood, using disposable cuvettes and a novel proprietary technology that the applicant company uses in its other products. Preliminary results indicate that this method is fast and convenient, but may not yield clinically acceptable accuracy. The second approach is to develop a """"""""hemolytic cuvette"""""""" in hope of achieving greater precision in hemolyzed samples. The third approach is to evaluate methods for separating red blood cells from plasma without centrifugation, and then making the spectrophotometric measurements in plasma. Results from the proposed Phase I experiments will allow the investigators to select the best measurement system for the bilirubinometer, which will then be brought to a manufacturable form during Phase II.