Research
New Faculty Publication: Chapters in “Oxygen Transport to Tissue XLV” – Dr. Akitoshi Seiyama and Prof. Monte Cassim
Dr. Akitoshi Seiyama, Director of AIU’s Creative Design & Data Science Center, and Prof. Monte Cassim, president of AIU, authored or co-authored chapters in the new book Oxygen Transport to Tissue XLV. Please read on for a summary of each of the chapters.
Development of a Remote Health-Monitoring System for Frail People: A Preliminary Study
Akitoshi Seiyama, Nami Konishi*, Tatsuro Miura*, Sayaka Okahashi*, Monte Cassim
Respiratory and cardiovascular functions decline with age in elderly individuals. Consequently, the incidence of chronic respiratory and cardiovascular diseases increases with age. Heart disease and pneumonia are the leading causes of death in Japan. Given the pathophysiological nature of these diseases, patients inevitably require monitoring of their cardiac and pulmonary functions, such as heart rate and arterial blood oxygenation, as systemic parameters. In addition, monitoring skin temperature and humidity as local parameters is preferable for elderly individuals to maintain healthy daily conditions. In the present study, we developed a wearable vital sign monitoring system and validated the accuracy of the device under development as compared to authorised medical devices that measure these systemic and local parameters in the peripheral tissue of the palm. For the systemic parameters, mean values showed no significant differences between the two devices, but the data bias was greater for the device under development. For the local parameters, mean values showed significant differences between the two devices; however, the data bias was the same for both devices. The acceptable data acquisition of the device under development was approximately 89%, with error acquisition mainly caused by the measurement of systemic parameters. We conclude that further improvements in measurement of systemic parameters are required to increase the data acquisition beyond 90%.
Read the full chapter here.
*Dr. Konishi, Dr. Miura, and Dr. Okahashi are visiting researchers at AIU’s Creative Design & Data Science Center.
Relevance Between Reduction of SpO2 and Parasympathetic Nervous Activity During Sleep
Kentaro Taniguchi, Akitoshi Seiyama, Akito Shimouchi
Sleep apnea syndrome (SAS) is associated with cardiopulmonary and dental nasopharyngeal diseases. The blood oxygen saturation (SpO2) detected using pulse oximetry is a diagnostic screening method for SAS. SAS severity is assessed using the oxygen desaturation index (ODI), which measures the number of times the SpO2 decreases by more than 3% for longer than 10 s. This study investigated the association between reduced SpO2 and parasympathetic nervous system activity (PSNA) during night sleep in young adults (n = 63; aged 20-32 years). Changes in PSNA were measured every minute for 24 h during a free-moving day using an ActiveTracer accelerometer. Pulse oximetry was performed simultaneously during sleep. All participants had significantly lower PSNA when the SpO2 decreased by 3% or more than when it did not. There were no significant differences in PSNA when an ODI cutoff of 5 events/h was used. However, participants with an ODI >5 events/h had significantly lower PSNA during normal SpO2 than those with an ODI <5 events/h, suggesting an association between SpO2 desaturation and PSNA decline during sleep. A high ODI may indicate reduced PSNA levels during sleep, affecting sleep efficiency. Treatment aimed at reducing the ODI may improve sleep quality, even in young adults.
Read the full chapter here.
Neural Function Desynchronisation in Left and Right Dorsolateral Prefrontal Cortices During Virtual Reality Earthquake Video Viewing
Hikari Otsuka, Sayaka Okahashi*, Akitoshi Seiyama
During natural disasters such as earthquakes, individuals are required to evacuate calmly amidst significant emotional distress, presenting a considerable challenge. Very few studies have measured emotional responses during disasters, and the emotional responses and brain activity during natural disasters are poorly understood. Therefore, this study aimed to investigate emotional responses during an earthquake using immersive virtual reality (VR), focusing on changes in neural connectivity in the left and right dorsolateral prefrontal cortices (DLPFCs). We measured changes in total haemoglobin concentration (Δtotal-Hb) using 2-channel near infrared spectroscopy (NIRS) while 24 healthy young adults viewed earthquake and neutral videos through a head-mounted display (HMD). Spearman’s correlation analysis was applied to the time variation in Δtotal-Hb in the left and right DLPFCs, independently for seismic or neutral video conditions. The findings revealed a negative correlation between the left and right total haemoglobin concentration changes during the earthquake video (ρ = −0.53). Conversely, individuals exposed to the neutral video exhibited a positive correlation (ρ = 0.75). The present steady-state analysis suggests that emotional changes induced by virtual earthquake videos disturbed steady-state neural synchronisation between the left and right DLPFCs.
Read the full chapter here.
*Dr. Okahashi is a visiting researcher at AIU’s Creative Design & Data Science Center
Creative Design & Data Science Center
For more information about AIU’s Creative Design & Data Science Center (CreDDS Center), including past publications, see the annual reports on the CreDDS Center page.