内田 勇人

大都市在住の後期高齢者を対象に,COVID-19感染拡大前後での通いの場の参加状況の変化とその関連要因を検討した.2021年8月に郵送調査を行い,29,490名のデータから感染拡大前後での通いの場種別の参加状況を従属変数,基本属性や生活状況,健康状態を独立変数としたロジスティック回帰分析を実施した.感染拡大後の新規参加は,通いの場種別を問わず非対面交流と有意であった.さらに,通いの場の種別によっては,新規参加が性別や居住形態,所得,教育歴,スマートフォン使用と有意に関連していた.一方,参加中断は,通いの場種別を問わず女性やフレイルと有意であった.通いの場の種別によっては,参加中断が婚姻状況,スマートフォン使用,就労に加え,非対面交流や主観的健康感と有意に関連していた.以上より,通いの場の種類や内容に応じて,高齢者が通いの場への参加自粛または中断へと至る過程は異なる可能性が示唆された.(著者抄録)

Maximizing healthy life expectancy is essential for enhancing well-being. Optimal exercise intensity is crucial in promoting health and ensuring safe rehabilitation. Since heart rate is related to exercise intensity, the required exercise intensity is achieved by controlling the heart rate. This study aims to control heart rate during exercise by dynamically adjusting the load on a bicycle ergometer using a proportional-integral (PI) control. The choice of PI parameters is very important because the PI parameters significantly affect the performance of heart rate control. Since the dynamic characteristics of heart rate relative to work rate vary widely from subject to subject, the PI parameters for each subject must be determined individually. In this study, PI parameters are optimized directly from exercise data using a data-driven design approach. Thus, the proposed method does not require excessive exercise of the subject to model heart rate dynamics. Using the proposed method, the heart rate can be controlled to follow a designed reference model so that the heart rate is safely increased to the desired value. The quantitative evaluation of the control results of fifteen healthy volunteers confirmed that the proposed method improved the control error of the target heart rate trajectory by approximately 40%, regardless of gender or age. In addition, it was shown that control parameters from the exercise experiment also indicate that females are more likely than males to have an elevated heart rate at the same load.