Nocturnal activity and immobility across aging (50-98 years) in healthy persons

The Social Utility and Health Benefits for Older Adults of Amenity Buildings in China's Urban Parks: A Nanjing Case Study

As China's population rapidly ages, research and discussion on how to better optimize public spaces for the elderly's health and benefit continue to deepen. This study uses observational surveys and questionnaires to investigate the elderly visitors of Nanjing's urban parks and explore the impact the parks' amenity buildings (structures built to provide visitors with conveniences, e.g., shelters and pavilions) has on their health and associated socialization tendencies. Data were collected from ten amenity buildings in ten separate parks to compose a total dataset of 728 activity statistics and 270 valid questionnaires. The study's results indicate that amenity buildings significantly increase opportunities for older adults to socialize and thereby can increase this demographic's associated health benefits. The social activities formed around amenity buildings are found to improve social interactions and connectedness among older adults more compared to other age groups. Elderly participation in social activities is also found to positively correlate with environmental characteristics. High-quality landscapes ensure healthy development of social activities within amenity buildings and promote the occurrence and continuation of social interactions. In order of highest to lowest impact on elderly activities, the following factors were identified and scored: amenity building scale, lighting, comprehensive surrounding environment, surrounding amenities, water features, and vegetation. This research also reveals that among existing amenity buildings, there is insufficient support for certain activities and therefore, parks need to be improved to address this deficiency. Overall, this study indicates that under China's current aging trends, amenity buildings have become an especially important infrastructure within urban public space, and their design trend is to incorporate the dual characteristics of "recreation + society".

Sleep Posture Classification using a Convolutional Neural Network

Sleep is a process of rest and renewal that is vital for humans. However, there are several sleep disorders such as rapid eye movement (REM) sleep behaviour disorder (RBD), sleep apnea, and restless leg syndrome (RLS) that can have an impact on a significant portion of the population. These disorders are known to be associated with particular behaviours such as specific body positions and movements. Clinical diagnosis requires patients to undergo polysomnography (PSG) in a sleep unit as a gold standard assessment. This involves attaching multiple electrodes to the head and body. In this experiment, we seek to develop non-contact approach to measure sleep disorders related to body postures and movement. An Infrared (IR) camera is used to monitor body position unaided by other sensors. Twelve participants were asked to adopt and then move through a set of 12 pre-defined sleep positions. We then adopted convolutional neural networks (CNNs) for automatic feature generation from IR data for classifying different sleep postures. The results show that the proposed method has an accuracy of between 0.76 & 0.91 across the participants and 12 sleepposes with, and without a blanket cover, respectively. The results suggest that this approach is a promising method to detect common sleep postures and potentially characterise sleep disorder behaviours.

Impact of Poor Sleep on Physical and Mental Health in Older Women

Many aspects of sleep and circadian rhythms change as people age. Older adults usually experience decrease in sleep duration and efficiency, increase in sleep latency and fragmentation, high prevalence of sleep disorders, and weakened rest-activity rhythms. Research evidence suggests that women are more likely to report aging-related sleep problems. This review presents epidemiologic and clinical evidence on the relationships between sleep deficiency and physical and mental outcomes in older women, explores potential mechanisms underlying such relationships, points out gaps in the literature that warrant future investigations, and considers implications in clinical and public health settings.

Detection and Classification of Movements in Bed using Load Cells

The quality of our life is tied to the quality of our sleep. People with sleep deficits may experience impaired performance, irritability, lack of concentration, and daytime drowsiness. Increased mobility in bed can be a sign of disrupted sleep. Therefore, body movements in bed represent an important behavioral aspect of sleep. In this paper, we propose a method for detection and classification of movement that uses load cells placed at each corner of a bed. The detection of movements is based on short-term analysis of the mean-square differences of the load cell signals. Movement classification is based on features extracted from a wavelet-based tiresolution analysis (MRA) to classify the type of movement into two classes: small and large. A linear classifier is trained on each level of the MRA, and the decisions of the 4 classifiers are combined using a Bayesian combination rule. The method is evaluated on load cell data collected from 6 subjects. Each subject performed 5 trials composed of 20 pre-defined movements including small shifts of position to large movements of torso and limbs. The performance measure for the detection problem is the equal error rate (EER). We show that the detection method achieves a 2.9% EER and that the classification method has a classification error of 4%.

A method for classification of movements in bed

Sleep is characterized by episodes of immobility interrupted by periods of voluntary and involuntary movement. Increased mobility in bed can be a sign of disrupted sleep that may reduce sleep quality. This paper describes a method for classification of the type of movement in bed using load cells installed at the corners of a bed. The approach is based on Gaussian Mixture Models using a time-domain feature representation. The movement classification system is evaluated on data collected in the laboratory, and it classified correctly 84.6% of movements. The unobtrusive aspect of this approach is particularly valuable for longer-term home monitoring against a standard clinical setting.

Sex differences in subjective and actigraphic sleep measures: a population-based study of elderly persons

STUDY OBJECTIVES

To investigate and explain sex differences in subjective and actigraphic sleep parameters in community-dwelling elderly persons.

DESIGN

Cross-sectional study.

SETTING

The study was embedded in the Rotterdam Study, a population-based study.

PARTICIPANTS

Nine hundred fifty-six participants aged 59 to 97 years.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Participants wore an actigraph and kept a sleep diary for an average of 6 consecutive nights. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index. Unadjusted sex differences in sleep parameters were assessed with t tests. Women reported shorter total sleep time, a less favorable sleep-onset latency, lower sleep efficiency, and worse global sleep quality, as compared with men. When assessed with actigraphy, however, women were found to have longer and less-fragmented sleep than men. Sex differences in diary-reported sleep duration and other subjective sleep parameters were attenuated by adjustment for marital status, the use of sleep medication, and other covariates, but all sex differences remained significant in a multivariate-adjusted model. Sex differences in actigraphic sleep parameters were barely attenuated by multivariate adjustment, although the shorter actigraphically measured sleep duration in men was partly explained by their higher alcohol consumption. Some covariates (eg, sleep medication) had a different relationship with diary-reported or actigraphic total sleep time in men and women.

CONCLUSIONS

If assessed by diary or interview, elderly women consistently reported shorter and poorer sleep than elderly men. In contrast, actigraphic sleep measures showed poorer sleep in men. These discrepancies are partly explained by determinants of sleep duration, such as sleep medication use and alcohol consumption.

Wearable systems for monitoring mobility-related activities in older people: a systematic review

OBJECTIVE

The use of wearable motion-sensing technology offers important advantages over conventional methods for obtaining measures of physical activity and/or physical functioning in aged individuals. This review aims to identify the actual state of applying wearable systems for monitoring mobility-related activity in older populations. In this review we focus on technologies and applications, research designs, feasibility and adherence aspects, and clinical relevance of wearable motion-sensing technology.

DATA SOURCES

PubMed (MEDLINE since 1990), Ovid (BIOSIS, CINAHL), and Cochrane (Central) and reference lists of all relevant articles were searched.

REVIEW METHODS

Two authors independently reviewed randomized and non-randomized trials on people above 65 years systematically. Quality of selected articles was scored and study results were summarised and discussed.

RESULTS

Two hundred and twenty-seven abstracts were considered. After application of inclusion criteria and full text reading, 42 articles were taken into account in a full text review. Twenty of these papers evaluated walking with step counters, other papers used varying accelerometry approaches for obtaining overall activity measures (n = 16), or for monitoring changes in body postures and activity patterns (n = 17). Seven studies explicitly mentioned feasibility and/or adherence aspects. Eight studies presented outcome evaluations of interventions. Eight articles were representing descriptive research designs, three articles were using mixed descriptive and exploratory research designs, 23 articles used exploratory research-type designs, and eight articles used experimental research designs.

CONCLUSION

Although feasible methods for monitoring human mobility are available, evidence-based clinical applications of these methods in older populations are in need of further development.

[Use of telemonitoring by elders at home: actual practice and potential]

DESCRIPTION

The use of telemonitoring services by elders is increasing. In this regard, occupational therapists have been recommending emergency call systems linked to a central monitoring system.

OBJECTIVES

This study sought to document the actual and potential uses of telemonitoring services with an elderly population in a home support context and the impact of these services on occupational therapy practice.

METHODOLOGY

To meet these objectives, a literature review on telemonitoring practices was completed and results were organized according to the Canadian Model of Occupation Performance.

RESULTS

Evidence suggests that new technology and telecommunication is efficacious for monitoring elder's physical and cognitive components, and can have positive impacts on elders' affective component, and social, physical and institutional environment. In regards to monitoring occupations in the home, research and development is promising for personal care such as mobility, sleeping, medication and life routine follow-up.

PRACTICE IMPLICATIONS

The arrival on the market of new products for telemonitoring services will allow easy and continuous monitoring of elder's progress at home in a non invasive manner, and will enable quick intervention when there is a change in day-to-day occupations.

Nonexercise movement in elderly compared with young people

The association between free-living daily activity and aging is unclear because nonexercise movement and its energetic equivalent, nonexercise activity thermogenesis, have not been exhaustively studied in the elderly. We wanted to address the hypothesis that free-living nonexercise movement is lower in older individuals compared with younger controls matched for lean body mass. Ten lean, healthy, sedentary elderly and 10 young subjects matched for lean body mass underwent measurements of nonexercise movement and body posture over 10 days using sensitive, validated technology. In addition, energy expenditure was assessed using doubly labeled water and indirect calorimetry. Total nonexercise movement (acceleration arbitrary units), standing time, and standing acceleration were significantly lower in the elderly subjects; this was specifically because the elderly walked less distance per day despite having a similar number of walking bouts per day compared with the young individuals. The energetic cost of basal metabolic rate, thermic effect of food, total daily energy expenditure, and nonexercise activity thermogenesis were not different between the elderly and young groups. Thus, the energetic cost of walking in the elderly may be greater than in the young. Lean, healthy elderly individuals may have a biological drive to be less active than the young.

The use of the Actiwatch–Neurologica® system to objectively assess the involuntary movements and sleep–wake activity in patients with mild–moderate Huntington’s disease

Huntington's disease (HD) is a neurodegenerative disorder characterised by cognitive, psychiatric and motor abnormalities including a range of involuntary movements. Currently, assessment of these movements involves the use of subjective rating scales such as the Unified Huntington's Disease Rating Scales (UHDRS) for bradykinesia and maximal dystonia and chorea, without any objective measures. As new therapies emerge, it is critical that an objective means of evaluating these abnormal movements is developed and we have investigated the use of a wrist-worn activity monitor, the Actiwatch-Neurologica, to determine whether these movements can be measured. In addition, this activity monitor and subjective reports were used to objectively measure the degree of sleep disruption in these same HD patients. Eight patients with mild-moderate HD and 8 age- and sex-matched control subjects wore the monitor for a period of 48 hours and recorded in a diary whether they were asleep or awake for each hour over the 2-day period. Assessment of various movement parameters revealed that HD patients exhibited significantly greater total and maximum activity levels and spent longer performing high acceleration movements while they were awake compared with controls. During sleep, patients not only showed significantly more activity and spent more time making high acceleration movements, but they also made significantly more movements than control subjects. These results demonstrate that the Actiwatch-Neurologica activity monitor can be used to objectively assess movements in HD patients during periods of high activity as well as during sleep.

An assessment of sleep disturbance in patients before and after total hip arthroplasty

Patients with osteoarthritis commonly complain of sleep disturbance that may be due to pain. Osteoarthritic hip pain is commonly alleviated by total hip arthroplasty (THA). Forty-eight patients waiting for THA completed a sleep questionnaire and were monitored using actigraphy and sleep diaries for 4 to 5 nights, 1 month before and 3 months after surgery. For the group as a whole, significant improvements were seen in subjective and objective measures of sleep after THA. In this study, 75% of participants reported that their sleep was never or rarely disturbed by hip pain after surgery. Actigraphy indicated significant reductions in time in bed and activity during sleep, more efficient sleep and less fragmented (restless) sleep. Differences between patients aged < 65 and > or = 65 years were observed. These findings support the hypothesis that relief from the pain of osteoarthritis as a result of THA improves sleep quality. Improvements in sleep contribute to the improved quality of life and day-to-day functioning seen after THA.

The role of actigraphy in sleep medicine

During the last decade actigraphy (activity-based monitoring) has become an essential tool in sleep research and sleep medicine. The validity, reliability and limitations of actigraphy for documenting sleep-wake patterns have been addressed. Normative data on sleep-wake patterns across development have been collected. Multiple studies have documented the adequacy of actigraphy to distinguish between clinical groups and to identify certain sleep-wake disorders. Actigraphy has also been shown to be effective in documenting the effects of various behavioral and medical interventions on sleep-wake patterns. Actigraphy is less useful for documenting sleep-wake in individuals who have long motionless periods of wakefulness (e.g. insomnia patients) or who have disorders that involve altered motility patterns (e.g. sleep apnea). Potential users should be aware of a number of pitfalls of actigraphy: (1) validity has not been established for all scoring algorithms or devices, or for all clinical groups; (2) actigraphy is not sufficient for diagnosis of sleep disorders in individuals with motor disorders or high motility during sleep; (3) the use of computer scoring algorithms without controlling for potential artifacts can lead to inaccurate and misleading results.

Effects of age on activity patterns after coronary artery bypass surgery

OBJECTIVE

To examine the effect of age on activity patterns, including circadian rhythms and levels, after coronary artery bypass surgery (CABS).

DESIGN

Repeated measures, correlational.

SETTING

Northeastern university-affiliated tertiary coronary care center.

SUBJECTS

Eight middle-aged (mean age = 57 years) and 14 older (mean age = 72 years) adults who had undergone first, isolated CABS.

OUTCOME MEASURES

Wrist actigraph measures of levels (daytime activity) and circadian patterns of activity (acrophase, amplitude, percent rhythm, mesor), self-reported postoperative clinical activity milestones, and Sickness Impact Profile subscales of ambulation dysfunction and sleep-rest.

INTERVENTION

Measurement of activity over postoperative days 2 through 5, including wrist actigraphy, Sickness Impact Profile ambulation and sleep-rest subscales, and daily clinical activity milestones.

RESULTS

Repeated measures ANOVA was used in the data analysis. Statistically significant increases were found in percent rhythm (P <.001), amplitude (P <.001), activity level (P <.001), and clinical activity milestones (P <.001) over postoperative days 2 through 5. Significant effects of age were found on amplitude (P =.02) and percent rhythm (P =.008). Significant age-by-time effects were found for circadian amplitude (P =.03) and percent rhythm (P =.02). There was a nonstatistically significant (P =.07) age by time interaction effect on daytime activity. Trends in amplitude, percent rhythm, and daytime activity indicated that these activity parameters increased more slowly in older adults, compared with middle-aged adults, after initially similar levels on postoperative days 2 and 3.

CONCLUSION

Both middle-aged and older adults increase daily activity and the strength of circadian activity pattern over days 2 through 5. However, these variables increase more rapidly in middle-aged adults after essentially identical levels on postoperative days 2 and 3.

Sleep complaints in community-dwelling older persons: prevalence, associated factors, and reported causes

OBJECTIVES

To determine the prevalence rates of self-reported sleep complaints and their association with health-related factors.

DESIGN

A cross-sectional study.

SETTING

People living in the community.

PARTICIPANTS

A total of 2398 noninstitutionalized individuals, aged 65 years and older, residing in the Veneto region, northeast Italy.

MEASUREMENTS

Odds ratios for the association of sleep complaints with potential risk factors.

RESULTS

The prevalence of insomnia was 36% in men and 54% in women, with increased risks for women (odds ratio (OR) = 1.69, 95% CI: 1.3-2.1), depression (OR = 1.93, 95% CI, 1.5-2.5), and regular users of sleep medications (OR = 5.58, 95% CI, 4.3-7.3). About 26% of men and 21% of women reported no sleep complaints. Night awakening, reported by about two-thirds of the participants, was the most common sleep disturbance. Women and regular users of sleep medications had significantly increased odds for insomnia and for not feeling rested upon awakening in the morning. Depressive symptomatology was more strongly associated with insomnia and night awakening than with awakening not rested, whereas physical disability was more strongly associated with awakening not rested than with the other two sleep disturbances.

CONCLUSION

Our findings show that sleep complaints, highly common among older Italians, are associated with a wide range of medical conditions and with the use of sleep medications. Further longitudinal studies are needed to investigate the causes and the negative health consequences of sleep disturbances to improve both the diagnosis and treatment.