Kohei Higuchi

Basic study on evaluation of navigator's mental workload by sticking plaster-type sensor

The evaluation of mental workload using a pysiological index is useful to read the performance of ship bridge teammates: a captain, a duty officer, a helmsman, and a pilot. The physiological indices, heart rate variability (R-R interval), salivary amylase and nitrate, and facial (nasal) temperature, are fine indices for picking up during their ship handling. It usual evaluates for veteran-seafarers on both of simulator and real ship by subjective evaluations; however, we think it is not enough, and need to utilize the numerical values for mental and performance evaluation. This paper proposes that physiological index and body acceleration do well for evaluating navigators mental workload and performance for real ship and simulator-based ship handling. The result shows the heart rate variability and body accelerations read their mental workload and performance well.

Daisy-chain Shape Wearable Health Monitoring System by Using Fuzzy Logic Heart-Rate Extraction

Continuous human monitoring is substantially useful to realize a high QoL (quality of life) society. In the previous work, we fabricated a prototype system for monitoring an electrocardiograph (ECG), heart rate (HR), 3 axes human body acceleration, temperature for human body and human circumstances, simultaneously. These data are transmitted to the host PC and used for analyzing the human activities and conditions such as a heart rate variability (HRV). The HRV that calculated from HR is valuable for recognizing a mental or physical stress of human subjects. In this study, we demonstrate a fuzzy logic HR extraction algorithm on the prototype system to realize an autonomous HRV monitoring system. On-board fuzzy algorithm will reduce the communication traffic and improve an accuracy of the HR extraction. From the implementation result, the error ratio of the HR extraction is improved from 0.9 % to 0.4 %.