Novel Instrument for Measuring Oxygen-Equilibrium Curve

Introduction: Hemoglobin plays a crucial role in the delivery of oxygen from the lungs to the body's tissues. The binding function of hemoglobin can be directly measured by simultaneously assessing both the oxygen pressure and saturation level of hemoglobin while changing the oxygen content from zero to a reasonable maximum, then back to zero. The curve describing the dependence of hemoglobin saturation as a function of oxygen pressure is called the Oxygen Equilibrium Curve (OEC). The characteristic point of the OEC curve is the oxygen pressure corresponding to 50% saturation of hemoglobin (P50).

Current instruments capable of measuring OEC have a variety of limitations that have thus far limited the wider applications for OEC measurements in pharmacological and medical applications. This includes large blood sample sizes, complex consumables, and lengthy test procedures.

Aim: The goal of our current development is to suggest a novel method for improved measurement of P50 and the OEC curve.

Methods: OxyDial's OEC measurement methodology prioritizes improvements in four key areas when compared to currently-available instruments:

1. Full spectrum absorption spectroscopy is used to measure hemoglobin saturation. This increases measurement precision and enables the detection of Met-Hemoglobin.

2. Oxygen pressure is measured using the lifetime of phosphorescent dye. This simplifies the instrument and negates the need for calibrations which would otherwise be required.

3. An enzymatic reaction is used to reduce oxygen pressure from atmospheric levels to zero. This decreases the required sample volume to 10uL, and avoids the need for gas cylinders.

4. Samples are contained in a small glass capillary (similar to a micro-hematocrit capillary), ensuring contamination-free cleaning and operation, as the only component in direct contact with blood is the disposable capillary itself. Capillary temperature can be precisely controlled to a level of 10mC.

Results: The suggested method provides significant improvements compared to methods used in the older instruments, which are limited to 2 wavelengths, and necessitates the use of Clark's electrodes, a 1 cm optical cuvette with a stirrer, and a defoaming agent. In contrast, OxyDial's novel OEC method and instrumentation have been proven to provide more reliable and precise operation and require no significant service or deployments. A single OxyDial OEC instrument could conduct 30 full tests in a day, with the simple operation allowing a single operator to run up to 4 instruments simultaneously.

Conclusion(s): We recommend switching from the older OEC testing methods to novel OxyDial OEC testing methods.

Pochron:Pfizer: Ended employment in the past 24 months. Gaputan:Pfizer: Ended employment in the past 24 months.