2021 Volume 6 Issue 1 Pages 1-9
The primary aim of our research is to complete physiological index to evaluate mental workload. We focus on salivary NO3- as an index, which is emitted to blood vessels from vascular endothelial cells when a human body receives mental workload. The development of a device to measure NO3- in vascular endothelial cells is thus required for the evaluation of mental workload. The device developed here is composed of field-effect transistors and ion-selective membranes. We have adopted a polymer for use with an ion-selective membrane. Two experiments were performed to verify the drift in the device characteristics and to validate the characteristics of the polymer as the ion-selective membrane. Verified experimental results indicated that the polymer was useful as ion-selective membrane material, which has less drift characteristics for a long time measurement. Validated experimental results indicated that NO3- device with new polymer KP-13 has the effectiveness of measurement of mental workload on the spot, compared with values from NO3- device with KP-13 and other physiological indices.
