BackgroundThe free-space broadband frequency-modulated near-infrared (NIR) photon transmission and backscattering mode technique has been used in this paper as an optical biosensor method.PurposeThe purpose is to measure, identify, and extract the optical properties of different blood types.Patients and methodsThe method depends on the measurements of broadband frequencies ranging from 30 up to 1,000 MHz to predict two important parameters related to the incident-modulated signal. Blind samples collected from 30 patients were examined using the optical NIR transmission mode system, and an additional 40 blood samples from random patients were examined using the optical NIR reflection mode system. The study is divided into two stages: The first stage is dedicated to measuring the insertion loss and insertion phase over 30–1,000 MHz in a transmission mode to characterize the behavior of modulated photons as they interact with the blood samples. The second stage is dedicated to performing noninvasive backscattering measurements using the optical band developed to match the first stage results.ResultsIn this paper, we have created an indexed database using optical transmission mode measurements, and then mapped it to a reflection noninvasive measurement to identify the blood types. Then for the purpose of device accuracy, we randomly selected 480 new human subjects to measure the false-negative error percentage. This method is novel in terms of using an optical system to measure and identify blood types without collecting blood samples.ConclusionThe novel approach shows a highly accurate method in identifying different blood types instantaneously using optical sensing for both in vitro and in vivo procedures, thereby saving time and effort.