Mayumi Oyama-Higa

Computerized assessment of communication for cognitive stimulation for people with cognitive decline using spectral-distortion measures and phylogenetic inference

Therapeutic communication and interpersonal relationships in care homes can help people to improve their mental wellbeing. Assessment of the efficacy of these dynamic and complex processes are necessary for psychosocial planning and management. This paper presents a pilot application of photoplethysmography in synchronized physiological measurements of communications between the care-giver and people with dementia. Signal-based evaluations of the therapy can be carried out using the measures of spectral distortion and the inference of phylogenetic trees. The proposed computational models can be of assistance and cost-effectiveness in caring for and monitoring people with cognitive decline.

Characteristic Extraction of Mental Disease Patients by Nonlinear Analysis of Plethysmograms

We measured the pulse waves of 196 mentally ill patients and 113 healthy students. Using heartbeat changes, we calculated the values of their sympathetic nerves, parasympathetic nerves, and autonomic nerve balance. In addition, we calculated the largest Lyapunov exponents (LLE) by non‐linear analysis of plethysmograms. Values were analyzed by group. The results revealed a significant relationship between LLE and the autonomic nerve balance. The sympathetic nerve values in the patient group were significantly higher than those in the student group, whereas the LLE values were significantly lower. Furthermore, we illustrated the dynamic change in the results for single participants over several testing times. The measurement of pulse waves is easy and economical and does not put a strain on the subject. Additionally, these values can provide information that is more accurate than medical examination obtained from an interview. Our study contributed to the existing methodology in this field, and future data ...

A design of software adaptive to estimated user's mental state using pulse wave analysis

Recent study has shown that the pulse wave signal of human includes much information of humans mental condition. To get such information, measuring finger pulse wave is a non-invasive and convenient method. Then we analyze the measured pulse wave in frequency domain to investigate low- and high-frequency components whose the ratio can be used to estimate mental condition. We design and implement an API to retrieve users mental state easily and adaptively control a mobile phones software based on mental condition. To validate the benefit of API, we develop a mail filtering app on an Android phone and perform an experiment.

Effect of anesthesia on chaotic dynamics in finger plethysmograms

Chaotic dynamics in finger plethysmogram system was studied in relation to anesthesia processes. The experiments were conducted to observe the changes in finger plethysmogram before, during, and after the anesthesia for a surgery. The largest Lyapunov exponent of the plethysmograms was found to be significant and can be used to correlate the temporal variations of mental/physical status in the processes. There were lower values o f Lyapunov exponents during anesthesia, showing the block effect of anesthesia on central nervous system. There were highly Lyapunov exponents in recovery consciousness from anesthesia. To understand how the chaos arises and to explain the changes in the Lyapunov exponent in finger plethysmograms in experiments, a mathematical model consisting of baroreflex feedback and autonomous interactions was proposed and studied numerically. The decrease of the largest Lyapunov exponent in plethysmograms was explained successfully by the model in relation to the decreased chaoticity, and hence the depressed or blocked central nervous system in higher cerebral region.

The Effect of Touch Care for Baby by Mother

As the subject of child-rearing support has become more a part of society in modern times, in order to stimulate the spread of mother/child attachment formation through baby touch-care, the effectiveness of touch-care was verified by physical data collected by non-linear analysis, obtained from hospitalized mothers shortly after childbirth, as well as with mothers at home. Comparison of values of LLE and Autonomic Nerve Balance by means of fingertip pulse readings were taken before and after touch-care. As a result, the touch-care for baby with mother was effective to both baby and mother. The research suggests that: 1)the touch-care was effective to both baby and mother, 2) avoidance of using touch-care during hospitalization, 3) both mother and father acquiring skill in touch-care prior to childbirth, 4) after hospital discharge, implementation of touch-care in the home at play times and after bath times, are factors that contribute to emotional well-being.

Study of relations between the elderly and the care workers in the welfare facilities for the elderly, using non linear analysis of finger plethysmograms

The fingertip pulse waves of some of the elderly living in welfare facilities and a number of staff working in a daycare center for the elderly and a special nursing home for the elderly were measured several times throughout the day for a period of one or two days, and the chaotic information gained was analyzed using a non linear analysis method. As a result, differences were found in the value of the Lyapunov exponent in the fingertip pulse waves as information regarding vital signs reflecting the level of mental revitalization and the value of autonomic balance. The care workers were also asked to fill out a questionnaire. Information regarding the fingertip pulse waves of the elderly and the care workers is a basis for considering the improvement of the quality of care. Accordingly, the authors propose improvements in the content of the care work.

The Relations between the Mental Condition of the Care House Residents and Finger Plethysmograms

We measured the fingertip pulse waves of some of the elderly living in a care house (a welfare facility for the elderly) four times a day over two days to investigate their mental condition. We analyzed the chaotic information produced by the finger pulse waves using a nonlinear analysis method. The results of our research are as follows: 1) The Largest Lyapunov Exponent (LLE), which synchronizes to mental revitalization, rose when the care house residents felt happy. 2) After moderate movement (a stroll, etc.), the LLE was high. 3) The LLE did not rise when a regular action was carried out non‐vigorously to kill time. 4) When residents made contact (a phone call or letter, etc.) with a family member, the LLE was high. 5) The LLE of long‐term residents was high. 6) The majority of residents with high LLE moved into the care house in their early seventies. 7) The LLE of short‐term residents was low and their sympathetic nerves were high. 8) There was no relativity between the LLE and present age of the car...

Prospective Changes in Infertile Patients using Nonlinear Analysis

We measured pulse waves in 22 infertile women from the beginning of in vitro fertilization‐embryo transfer (IVF‐ET) through to pregnancy testing. The largest Lyapunov exponent (LLE) and autonomic nerve balance in the pregnancy group were significantly lower than that in the non‐pregnancy group. In this study, we measured plethysmograms of four women who became pregnant and 18 who did not, ten times from each. We calculated LLE and a value for the autonomic nerve balance; from this analysis, we conclude that a mental state that allows for the possibility of becoming pregnant is necessary for a successful pregnancy.

A Study of Care Work in Welfare Facilities for the Elderly, Using Non Linear Analysis of Finger Plethysmograms

The fingertip pulse waves of a number of staff working in a daycare center for the elderly and a special nursing home for the elderly were measured several times throughout the day for a period of one or two days, and the chaotic information gained was analyzed using a non linear analysis method. As a result, a relation between the staff’s length of career and the change of Largest Lyapunov Exponent (LLE) of the fingertip pulse waves that synchronized with the mental revitalization degrees and the tension of the sympathetic nerve was evident. The LLE of the staff with short careers dramatically changed and also took a long time to settle down again. In addition, staff LLE changed greatly after sessions of bathing assistance and watching residents with dementia. LLE measurements showed drops in some staff after a period of rest, but this was not the case for other staff. It can be concluded that the LLE is related to the length of the staff member’s career and what is actually done during working hours and...

Plethysmogram and EEG: Effects of Music and Voice Sound

We studied a relation of chaotic dynamics of finger plethysmogram to complexity of high cerebral center in both theoretical and experimental approaches. We proposed a mathematical model to describe emergence of chaos in finger tip pulse wave, which gave a theoretical prediction indicating increased chaoticity in higher cerebral center leading to an increase of chaos dynamics in plethysmograms. We designed an experiment to observe scalp‐EEG and finger plethysmogram using two mental tasks to validate the relationship. We found that scalp‐EEG showed an increase of the largest Lyapunov exponents (LLE) during speaking certain voices. Topographical scalp map of LLE showed enhanced arise around occipital and right cerebral area. Whereas there was decreasing tendency during listening music, where LLE scalp map revealed a drop around center cerebral area. The same tendency was found for LLE obtained from finger plethysmograms as ones of EEG under either speaking or listening tasks. The experiment gave results that...