Electro-Optical Monitoring and Analysis of Human Cognitive Processes

The achieved results have proven that the dedicated developed microelectrodes are able to sense the EDR in a very sensitive and fast way. Moreover, experiments, prior to the work presented here, prove that the achieved accuracy, input signal voltage and frequency ranges are suitable not only from biomedical monitoring point of view but also from the measurement system integration and miniaturization requirements. A non-invasive portable measurement system for the reliable and precise stress detection, based on the psycho-galvanic reflex monitoring, has been designed and developed. The system is based on an auto-balancing bridge measurement method offering digital processing and displaying of the measured data in the developed GUI operating under Windows XP platform. The measurement equipment uses microelectrodes developed for this purpose, and utilizes microcontrollers containing RF wireless communication modules to transfer data between the measurement unit and a personal computer. The complete measurement system has been designed with respect to the system accuracy, sensitivity and power management. Interesting outcome has been observed ­ the psychogalvanic reflex might be much more accurately sensed by the skin admittance phase, since this parameter reflects the human skin conductivity changes more significantly. The achieved measurement accuracy, input signal voltage and frequency ranges are suitable not only from human biomedical monitoring point of view but also from the measurement system integration and miniaturization requirements. Additionally, the proposed system is versatile and flexible, easy to be extended by other sensors' types (integrated or external with wireless communication feature) or different measurement approaches, which enables measurement of other physiologic parameters (e.g. body temperature, blood pressure, heart beat, etc.) There is no doubt that the developed measurement equipment offers new opportunities towards non-invasive wireless system for