Pilot Feasibility Study of a Novel Non-invasive Device for Diagnosis of Anemia

In low-resource areas of the world, anemia screening relies on analyzing a blood sample and is generally carried out in health facilities. Current anemia screening approaches have not yielded satisfactory results due to critical limitations including lack of a) reliable access to laboratory facilities, b) reliable non-invasive out-of-hospital screening tools for community health-workers, c) integration of anemia data across health systems and d) distinction between hemolytic and nutritional causes. Currently available non-invasive tools have unacceptably low accuracy and cannot distinguish between nutritional and hemolytic etiologies.

Prototype Anemia Diagnostic Assistant (ADA)

We have developed a prototype Anemia Diagnostic Assistant for non-invasive, simultaneous detection of two markers of anemia, blood hemoglobin and the End-Tidal carbon monoxide levels. The device comprises an optical sensor module and ETCO breath sampling module.

The unique and significant advantage of the instrument is its ability to detect, independently, two orthogonal variables that are required for differential diagnosis of the nutritional and hemolytic anemia:

1. Hemoglobin concentration using a non-invasive diffuse reflectance spectroscopy. Using high-fidelity, 11 wave-length spectral sensor, the device will provide optical quantification of hemoglobin levels. Optical hemoglobin sensing using diffused reflectance spectroscopy is well known, however; using traditional spectrophotometry instrumentation is very costly and thus impractical for this project. As a solution, we propose to use a validated commercially-available high accuracy 11-wavelength sensor within the visual and near-infrared (IR) range of the spectrum. The 11-wavelength spectrum will allow for sufficient accuracy in measuring the reflectance AND transmittance at isosbestic wavelengths on hemoglobin extinction curve as well as to compensate for the presence of melanin, which is a major interferant in optical determination of hemoglobin concentration. [9] The sensor was originally designed to collect data on the earlobe and/or the fingertip. Additional iterations include a sensor that straps around the wrist (similar to a smartwatch). Both versions of the device may be used in the study, and both feature standard USB or Bluetooth connectivity to ubiquitous mobile Android an iOS-based mobile platform .

2. End-tidal carbon monoxide. Using a non-invasive probe placed in proximity to the nostrils, the device will measure ETCO as a proxy measure of hemolysis. ETCO measurement as a measure for the presence of hemolysis is well documented in the medical literature and is commonly used in newborns units as a screening method for the presence of hemolysis [7,8,10]. A positive finding (presence of elevated levels of ETCO) will then prompt a referral for further hospital testing.

The objective of this study is to determine the hemoglobin and ETCO concentration in healthy volunteers using the prototype device and compare the results with the hemoglobin and ETCO concentrations obtained using standard of care devices and the CoSense system for the (ETCO measurement).