Freshman Year Science Fair Project

Won 1st at Massachusetts State Engineering and Science Fair

NeoHb: A Noninvasive Optical Biosensor Diagnosing Neonatal Anemia


Of all newborns in the NICU, 50% are admitted due to RDS, prematurity, or sepsis in the placenta/umbilical cord. These conditions lead to anemia in newborns, causing doctors to monitor their blood levels continuously. Doctors do this by performing the invasive CBC test, a challenging test to conduct on newborns since it requires the extraction of blood. This loss of blood can cause the anemia to worsen and lead to severe and chronic consequences such as low blood concentrations, poor growth, decreased activity, limited cardiovascular reserve, and low oxygen delivery to tissue. To ensure the safety of newborns, it is preferred to diagnose anemia noninvasively. This project displays the development of an optical biosensor that noninvasively diagnoses neonatal anemia. The sensor first goes through algorithms to determine the light absorption of hemoglobin (Hb). To eliminate the melanin light absorption and only analyze the hemoglobin light absorption, the sensor uses PPG (an optical technique used in ECG). Then, based on the calculated light absorption of Hb, a calibration curve of Hb (a concentration vs. light absorption linear function) will then be used to calculate Hb concentration in the newborn. The calculated Hb concentration (g/dL) will be compared with a benchmark Hb concentration, ultimately diagnosing anemia. This diagnosis is displayed on an app using multithreading algorithms and Bluetooth communication. Hb derivatives with differing absorption spectrums (oxygenated and deoxygenated) and Compton photon scattering across tissue were also taken into account when developing this sensor. In summary, the biosensor uses properties of light and isolates the light absorption of Hb to analyze the concentration of fetal hemoglobin in the arterial and venous blood of the newborn’s index finger and diagnose anemia.

Science Fair Board
STEM Board

Neonatal screening tests are used to diagnose neonatal anemia. False positives are common; there are more than 50 false positives for every true positive identified through neonatal screening. Current screening tests use small amounts of blood, which is less acurate. Anemia is worsened by blood loss and cannot be properly diagnosed using small amounts of blood.

What is Anemia?

Anemia is a condition in which you lack enough healthy red blood cells, also known as erythrocytes, to deliver oxygen to your body’s tissues. The proteins that carry the oxygen inside the red blood cells are called hemoglobin, which changes the hue of these cells

hemoglobin diagram

Erythrocytes are biconcave disk cells that are packed with hemoglobin.

Complete Blood Count (CBC) Test

The physician draws blood from the baby and measures both the hematocrit and the hemoglobin levels. Hematocrit is the measurement of the red blood cells compared to the total blood cell count. Hemoglobin is a protein carried by red blood cells that delivers oxygen to bodily tissues. Both measurements correlate well and either can be used to determine whether the baby has anemia.

Limitations of the CBC Test

It is an invasive test that requires a blood sample. If the baby has an underlying condition, such as hemophilia, CBC tests can cause serious and chronic side effects. Potential side effects for patients at risk include: low blood concentrations/worsening of anemia, low O2 delivery to tissues, poor growth, decreasing cardiovascular reserve (activity of heart)

Current Noninvasive Tests and Their Limitations

Primary noninvasive tests are performed via spectrophotometry to measure the concentration of hemoglobin. These devices are not applicable to newborns and babies, and showed higher biases and inaccuracy when tested in these populations. Current pricing per device ranges from $700.00 to $6,995.00.

competitor noninvasive hemoglbin analysis device
Challenges and Opportunities with HbF

Fetal hemoglobin is the main oxygen carrier protein for fetuses and stays in the red blood of infants until ~6 months after birth. Fetal hemoglobin has a different molecular structure than adult hemoglobin with different light absorption properties.

Key Innovation

The goal of this project is to determine a cost effective method to accurately measure fetal hemoglobin concentrations using spectrophotometry

fetal hemoglobin diagram
Performance Criteria: Developing a Proof of Concept in Adult Subjects
performance criteria
The Device

Hardware Overview

circuit diagram and sensor

The Sensor's Case

cad design for case and final prototype

Prototyping: Initial Design vs. Final Design

initial prototype and final prototype
More Information
Science Fair Presentation Slide Deck
Code for Sensor
Code for App