Non-invasive monitoring is the growing interest in the biomedical field using various classical as well as modern sensors. Many researchers are working on brain signals, to find out the low cost, non-invasive, simple and easy technique to predict various parameters related to the brain and or whole body. One of the most widely studied electrical brain signal is electroencephalogram (EEG); it is the rhythm produced by numerous brain cells when they are depolarized simultaneously. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain. EEG is very commonly used signal in the various brain related studies. Near infrared spectroscopy (NIRS) based optical signal captured from brain is known as cranial photoplethysmogram (CPPG).PPG signal is generated because of arterial blood volume change with each heartbeat. This optical technique is widely used to detect various cardiovascular diseases and microcirculation related diseases. EEG-CPPG concurrent modality can be used to investigate the synchronized activities of neurons and the subsequent hemodynamic response in human subjects. This simple and comparatively low-cost setup allows to measure hemodynamic activity in many situations when fMRI measurements are not feasible, e.g. for long-term monitoring at the bedside or even outside the lab via wireless transmission, in intensive care unit and in the operation theatres. This concurrent modality is used to study the various brain and heart related parameter and can be used in future for predicting the HeadHeart Interaction.

Keywords: Photoplethysmogram; Cranial Photoplethysmogram, Electroencephalogram; Brain Signals; Optical Technique; Head-Heart Interaction