Surface plasmon is an evanescent surface electromagnetic wave caused by collective and coherent free electron oscillation at a metal-dielectric interface. SPR (surface plasmon resonance, including propagating SPR when the metal film is continuous and localized SPR for isolated metal nanostructures) refers the excitation of surface plasmon by light. As the surface plasmon is confined to the metal-dielectric interface with an extension of only ~200nm from the interface, its resonant frequency is highly sensitive to the refractive index change at the interface. For example, binding of a monolayer of (bio-) molecules on the metal surface will lead to a detectable shift of resonant wavelength; therefore, SPR can be used as bio-sensor with high sensitivity to detect in real time biological binding events, such as DNA hybridization and antigen-antibody binding.
While the clinical ways of conducting health chekups can be inconvenient due to painful methods of extracting blood samples, they can also be unsafe if the same needles are used on multiple people in places misconducting medical ethics. Moreover, the blood glucose monitoring devices sold for domestics uses are extremely inefficient. The innovative approach taken by the new technique of non-invasive measurement of blood components like glucose, hemoglobin and creatinine levels have been proven extremely efficient, cost effective, and convenient to use. AERG is currently working on improving this technique. This technique provides a comfortable means of health checkup for the users as it does not involve taking blood samples but uses the PPG signal generated from a video recording of a fingertip of the user. This is also more suitable to be set up in remote areas because they lack resourced laboratories and trained personnel to carry out the invasive ways of extracting blood and sending for test. This research focuses on improving the efficiency of the technique by introducing various new comparison factors into the picture. This project will look into how the results vary with varying age and weight of the subject, compare the efficiency by recording the finger in an enclosed environment rather than an open one, investigate how applying pressure on the lower arm or the finger will affect the results. This technique still has large scopes of improvement and studying it further will aid in increasing its efficiency from 90% to beyond, making health checkups extremely convenient for people, on a regular basis.
