INTRODUCTION:Sleep disturbance is common at high altitude and likely driven by an exaggerated peripheral chemoreceptor response which leads to apnoeic episodes and arousal. We hypothesised that this heightened response is in part mediated through angiotensin II receptors in the carotid body. To examine this link, we studied the effect of angiotensin II receptor blocker on sleep disturbance.METHODS:Twenty participants paired by age, gender and ACE phenotype ascended to the Whymper Hut (5000 m) on Chimborazo in the Ecuadorean Andes as part of a double-blinded randomised placebo-controlled study of physiological mechanisms. Subjects were randomised to either losartan 100 mg daily or placebo. The primary outcome of sleep efficiency was measured using wrist-mounted actigraphs. One pair was excluded from analysis after descending before the end of the study due to acute mountain sickness.RESULTS:There was a significantly different response to altitude between the two groups (F=3.274, p=0.029), as a decline in sleep efficiency in the placebo group (F=10.259, p<0.001) was not replicated in the angiotensin II receptor blocker group (F=0.459, p=0.713).CONCLUSION:The absence of any significant sleep disturbance in the intervention group suggests that peripheral chemoreceptor hypersensitivity is largely mediated by angiotensin II receptor activation. However, further research is needed to confirm our findings and to study the potential mechanisms of action.

Background Late-life depression (LLD) is associated with poor social functioning. However, previous research uses bias-prone self-report scales to measure social functioning and a more objective measure is lacking. We tested a novel wearable device to measure speech that participants encounter as an indicator of social interaction. Methods Twenty nine participants with LLD and 29 age-matched controls wore a wrist-worn device continuously for seven days, which recorded their acoustic environment. Acoustic data were automatically analysed using deep learning models that had been developed and validated on an independent speech dataset. Total speech activity and the proportion of speech produced by the device wearer were both detected whilst maintaining participants' privacy. Participants underwent a neuropsychological test battery and clinical and self-report scales to measure severity of depression, general and social functioning. Results Compared to controls, participants with LLD showed poorer self-reported social and general functioning. Total speech activity was much lower for participants with LLD than controls, with no overlap between groups. The proportion of speech produced by the participants was smaller for LLD than controls. In LLD, both speech measures correlated with attention and psychomotor speed performance but not with depression severity or self-reported social functioning. Conclusions Using this device, LLD was associated with lower levels of speech than controls and speech activity was related to psychomotor retardation. We have demonstrated that speech activity measured by wearable technology differentiated LLD from controls with high precision and, in this study, provided an objective measure of an aspect of real-world social functioning in LLD.

Animal shelters tend to be stressful environments for dogs because of the sights, sounds, odors, and schedules that characterize shelter living. Levels of activity, including the amount of time spent resting or engaging in sedentary behaviors, may provide insights into overall welfare, especially when comparing shelter dogs' activity patterns to those of dogs in a home setting. The goal of this study was to compare the intensity and consistency of shelter dogs' and owned dogs' activity levels using three distinct methods for analyzing actigraphy data. Activity levels were measured for 19 owned dogs and 19 shelter dogs using triaxial accelerometers affixed to nylon collars on each dog's neck. Shelter dogs were more active than owned dogs during the first three quarters of the day, whereas owned dogs were more active than shelter dogs during the final quarter. Comparisons of shelter dogs' and owned dogs' ten consecutive hours of greatest activity also indicated that shelter dogs were more active earlier in the day than owned dogs. Furthermore, shelter dogs exhibited higher activity levels than owned dogs during this period of greatest activity. During the five consecutive hours of least activity, shelter dogs were more active than owned dogs. Finally, individual shelter dogs' activity patterns were more consistent day to day than owned dogs'. Our findings suggest that the shelter environment may inhibit dogs from resting. Further research is needed to assess the impacts of activity patterns on the health of shelter-housed dogs and to determine how quickly these dogs adjust to their owner’ schedules after adoption.

Canine obesity is usually managed with a combination of dietary caloric restriction and increasing physical activity, but no previous study has compared both of these strategies in a prospective randomised controlled trial. Thirteen overweight dogs (body condition score 6-9/9) were randomised to one of two interventions: dietary caloric restriction or physical activity. The dietary caloric restriction intervention comprised feeding a therapeutic weight loss diet, while the physical activity intervention comprised increasing the dog's current physical activity pattern by at least a third. The primary outcome measure was change in body weight, while secondary outcome measures included change in neck, thorax and abdominal circumference and change in physical activity measured by triaxial accelerometer. Bodyweight decreased significantly with the dietary caloric restriction (median -10% of starting body weight [SEW), 5 to -12%; P=0.028) but not with the physical activity intervention (-2% SBW, +3% to -6%; P=0.107). Abdominal circumference (dietary caloric restriction: median -12.0%; physical activity: median -7.8%, P=0.016) and thoracic circumference (dietary caloric restriction: median -7.5%, P=0.031; physical activity: median -3.6%, P=0.031) changed significantly in both groups. There was no change in activity levels within the dietary caloric restriction group, but vigorous activity increased significantly in the physical activity group (P=0.016). Dietary caloric restriction was more effective than physical activity for controlled weight loss in overweight pet dogs. Although advising owners to increase their dog's activity by a third led to a modest increase in measured vigorous physical activity, this was insufficient to promote weight loss on its own. (C) 2018 Elsevier Ltd. All rights reserved.

Background: Accelerometer-based technologies could be useful in providing objective measures of canine ambulation, but most are either not tailored to the idiosyncrasies of canine gait, or, use un-validated or closed source approaches. The aim of this paper was to validate algorithms which could be applied to accelerometer data for i) counting the number of steps and ii) distance travelled by a dog. To count steps, an approach based on partitioning acceleration was used. Thiswas applied to accelerometer data from13 dogs which were walked a set distance and filmed. Each footfall captured on video was annotated. In a second experiment, an approach based on signal features was used to estimate distance travelled. This was applied to accelerometer data from 10 dogs with osteoarthritis during normal walks with their owners where GPS (Global Positioning System) was also captured. Pearson's correlations and Bland Altman statistics were used to compare i) the number of steps measured on video footage and predicted by the algorithm and ii) the distance travelled estimated by GPS and predicted by the algorithm. Results: Both step count and distance travelled could be estimated accurately by the algorithms presented in this paper: 4695 steps were annotated from the video and the pedometer was able to detect 91%. GPS logged a total of 20,184 m meters across all dogs; the mean difference between the predicted and GPS estimated walk length was 211 m and the mean similarity was 79%. Conclusions: The algorithms described show promise in detecting number of steps and distance travelled from an accelerometer. The approach for detecting steps might be advantageous to methods which estimate gross activity because these include energy output from stationary activities. The approach for estimating distance might be suited to replacing GPS in indoor environments or others with limited satellite signal. The algorithms also allow for temporal and spatial components of ambulation to be calculated. Temporal and spatial aspects of dog ambulation are clinical indicators which could be used for diagnosis or monitoring of certain diseases, or used to provide information in support of canine weight-loss programmes.

The ability to objectively measure episodes of rest has clear application for assessing health and well-being. Accelerometers afford a sensitive platform for doing so and have demonstrated their use in many human-based trials and interventions. Current state of the art methods for predicting sleep from accelerometer signals are either based on posture or low movement. While both have proven to be sensitive in humans, the methods do not directly transfer well to dogs, possibly because dogs are commonly alert but physically inactive when recumbent. In this paper, we combine a previously validated low-movement algorithm developed for humans and a posture-based algorithm developed for dogs. The hybrid approach was tested on 12 healthy dogs of varying breeds and sizes in their homes. The approach predicted state of rest with a mean accuracy of 0.86 (SD = 0.08). Furthermore, when a dog was in a resting state, the method was able to distinguish between head up and head down posture with a mean accuracy of 0.90 (SD = 0.08). This approach can be applied in a variety of contexts to assess how factors, such as changes in housing conditions or medication, may influence a dog's resting patterns.

Background: The ability to make objective measurements of physical activity in dogs has both clinical and research applications. Accelerometers offer a non-intrusive and convenient solution. Of the commercialy available sensors, measurements are commonly given in manufacturer bespoke units and calculated with closed source approaches. Furthermore, the validation studies that exist for such devices are mounting location dependant, not transferable between brands or not suitable for handling modern raw accelerometry type data. Methods: This paper describes a validation study of n = 5 where 4 sensors were placed on each dog; 2 on a harness and 2 on a collar. Each position held two sensors from different manufacturers; Actigraph (which has previously been validated for use on the collar) and VetSens (which provides un-filtered accelerometry data). The aims of the study was to firstly evaluate the performance of an open-design method of converting raw accelerometry data into units that have previously been validated. Secondly, comparison was made between sensors mounted at each location for determining physical activity state. Results: Once the raw actigraphy data had been processed with the open-design method, results from a 7 day measurement revealed no significant difference in physical activity estimates via a cutpoint approach between the sensor manufacturers. A second finding was a low inter-site variability between the ventral collar and dorsal harness locations (Pearsons r(2) = 0.96). Conclusions: Using the open-design methodology, raw, un-filtered data from the VetSens sensors can be compared or pooled with data gathered from Actigraph sensors. The results also provide strong evidence that ventral collar and dorsal harness sites may be used interchangeably. This enables studies to be designed with a larger inclusion criteria (encompassing dogs that are not well suited for wearing an instrumented collar) and ensures high levels of welfare while maintaining measurement validity.

It is understood gait has the potential to be used as a window into neurodegenerative disorders, identify markers of subclinical pathology, inform diagnostic algorithms of disease progression and measure the efficacy of interventions. Dogs' gaits are frequently assessed in a veterinary setting to detect signs of lameness. Despite this, a reliable, affordable and objective method to assess lameness in dogs is lacking. Most described canine lameness assessments are subjective, unvalidated and at high risk of bias. This means reliable, early detection of canine gait abnormalities is challenging, which may have detrimental implications for dogs' welfare. In this paper, we draw from approaches and technologies used in human movement science and describe a system for objectively measuring temporal gait characteristics in dogs (step-time, swing-time, stance-time). Asymmetries and variabilities in these characteristics are of known clinical significance when assessing lameness but presently may only be assessed on coarse scales or under highly instrumented environments. The system consists an inertial measurement unit, containing a 3-axis accelerometer and gyroscope coupled with a standardized walking course. The measurement unit is attached to each leg of the dog under assessment before it is walked around the course. The data by the measurement unit is then processed to identify steps and subsequently, micro-gait characteristics. This method has been tested on a cohort of 19 healthy dogs of various breeds ranging in height from 34.2 cm to 84.9 cm. We report the system as capable of making precise step delineations with detections of initial and final contact times of foot-to-floor to a mean precision of 0.011 s and 0.048 s, respectively. Results are based on analysis of 12,678 foot falls and we report a sensitivity, positive predictive value and F-score of 0.81, 0.83 and 0.82 respectively. To investigate the effect of gait on system performance, the approach was tested in both walking and trotting with no significant performance deviation with 7249 steps reported for a walking gait and 4977 for a trotting gait. The number of steps reported for each leg were approximately equal and this consistency was true in both walking and trotting gaits. In the walking gait 1965, 1790, 1726 and 1768 steps were reported for the front left, front right, hind left and hind right legs respectively. 1361, 1250, 1176 and 1190 steps were reported for each of the four legs in the trotting gait. The proposed system is a pragmatic and precise solution for obtaining objective measurements of canine gait. With further development, it promises potential for a wide range of applications in both research and clinical practice.

Social Practice Theory offers a theoretical approach to understanding habitual, mundane and tacitly enacted practices that are performed within the domestic environment. To support the practical adoption of this theory, this paper reports and reflects upon a methodological application of Social Practice Theory which was used to investigate the domestic kitchen-based practices of older adults (aged 60+) in order to understand the role of food safety within the everyday performance of these. Social Practice Theory requires a research design that situates data generation techniques into the ‘space’ in which the practices are performed and gives equal investigative consideration to the physical and social spheres of practices. We demonstrate that these methodological principles necessitate the use of mixed methods, and this case study presents a ‘tool-kit’ of data generation techniques that produced visual, verbal, textual, technical and scientific data. Through the presentation of results at the level of the individual household, the case study demonstrates how the different data streams acted as analytical lenses which facilitated data corroboration and comparison, and provided the basis for a grounded conceptual elaboration of domestically situated food provisioning and handling practices and the role of food safety within these.

Background Late-life depression (LLD) is associated with a decline in physical activity. Typically this is assessed by self-report questionnaires and, more recently, with actigraphy. We sought to explore the utility of a bespoke activity monitor to characterize activity profiles in LLD more precisely. Method The activity monitor was worn for 7 days by 29 adults with LLD and 30 healthy controls. Subjects underwent neuropsychological assessment and quality of life (QoL) (36-item Short-Form Health Survey) and activities of daily living (ADL) scales (Instrumental Activities of Daily Living Scale) were administered. Results Physical activity was significantly reduced in LLD compared with controls (t = 3.63, p < 0.001), primarily in the morning. LLD subjects showed slower fine motor movements (t = 3.49, p < 0.001). In LLD patients, activity reductions were related to reduced ADL (r = 0.61, p < 0.001), lower QoL (r = 0.65, p < 0.001), associative learning (r = 0.40, p = 0.036), and higher Montgomery–Åsberg Depression Rating Scale score (r = −0.37, p < 0.05). Conclusions Patients with LLD had a significant reduction in general physical activity compared with healthy controls. Assessment of specific activity parameters further revealed the correlates of impairments associated with LLD. Our study suggests that novel wearable technology has the potential to provide an objective way of monitoring real-world function.

Background: Gait is a powerful tool to identify ageing and track disease progression. Yet, its high resolution measurement via traditional instruments remains restricted to the laboratory or bespoke clinical facilities. The potential for that to change is due to the advances in wearables where the synergy between devices and smart algorithms has provided the potential of ‘a gait lab on a chip’.Methods: Commercially available wearables for gait quantification remain expensive and are restricted to a limited number of characteristics unsuitable for a comprehensive assessment required within intervention or epidemiological studies. However, the increasing demand for low-cost diagnostics has fuelled the shift in how health-related resources are distributed. As such we adopt open platform technology and validated research methodologies to harmonise engineering solutions to satisfy current epidemiological needs.Results: We provide an introduction to conduct a routine instrumented gait assessment with a discrete, low-cost, accelerometer-based wearable. We show that the capture and interpretation of raw gait signals with a common scripting language can be straightforward and suitable for use within modern studies. We highlight the best approaches and hope that this will help compliment any analytical tool-kit as part of future cohort assessments.Conclusions: Deployment of wearables can allow accurate gait assessment in accordance with advocated methods of data collection as there is a strong demand for sensitive outcomes derived from pragmatic tools. This tutorial shows that instrumentation of gait using a single open source wearable is pragmatic due to low-cost and translational analytical methods to derive sensitive outcomes.

This paper describes the challenges and lessons learned in the experience-centered design (ECD) of the Spheres of Wellbeing, a technology to promote the mental health and wellbeing of a group of women, suffering from significant mental health problems and living in a medium secure hospital unit. First, we describe how our relationship with mental health professionals at the hospital and the aspirations for person-centric care that we shared with them enabled us, in the design of the Spheres, to innovate outside traditional healthcare procedures. We then provide insights into the challenges presented by the particular care culture and existing services and practices in the secure hospital unit that were revealed through our technology deployment. In discussing these challenges, our design enquiry opens up a space to make sense of experience living with complex mental health conditions in highly constrained contexts within which the deployment of the Spheres becomes an opportunity to think about wellbeing in similar contexts.

Gait is an important clinical assessment tool since changes in gait may reflect changes in general health. Measurement of gait is a complex process which has been restricted to bespoke clinical facilities until recently. The use of inexpensive wearable technologies is an attractive alternative and offers the potential to assess gait in any environment. In this paper we present the development of a low cost analysis gait system built using entirely open source components. The system is used to capture spatio-temporal gait characteristics derived from an existing conceptual model, sensitive to ageing and neurodegenerative pathology (e.g. Parkinson's disease). We demonstrate the system is suitable for use in a clinical unit and will lead to pragmatic use in a free-living (home) environment. The system consists of a wearable (tri-axial accelerometer and gyroscope) with a Raspberry Pi module for data storage and analysis. This forms ongoing work to develop gait as a low cost diagnostic in modern healthcare.

Exposure to high altitude induces hypertension that likely exacerbates arterial hypoxia via pulmonary vasoconstriction and ventilation-perfusion mismatching. Research has shown that inhibition of the renin–angiotensin–aldosterone system (RAAS) via an inhibitor provides an antihypertensive effect at rest during acute exposure to high altitude. Such effects may have benefits for exercise performance given the potential for improved arterial saturation, but has not been studied. PURPOSE: To assess the effects of the RAAS inhibitor losartan on maximal exercise performance at 5000 m. METHODS: Eighteen lowlanders were paired-matched for age, ACE gene status, previous altitude exposure and sex, with each of the pair randomly assigned to a group (men:women: losartan 6:3, placebo 6:3; age 40 ± 18 years; height 175 ± 9 cm; body mass 72.4 ± 12.4 kg; BMI 23.7 ± 2.2 kg/m2). A 100 mg once daily dose of either losartan or placebo (starch) was administered in a double-blind manner for 21 days, which included a slow 8-day ascent to 5000 m (Whymper Hut, Chimborazo, Ecuador). At sea-level and within 48 h of arrival at 5000 m, participants (pairs exercised within ~1 h of each other) completed a graded exercise test (GXT) to exhaustion on a supine cycle ergometer (Alticycle, BMRES). Ventilation (VE) and end-tidal gases were measured breath-by-breath (K4b2, Cosmed), and heart rate (HR, ECG), arterial oxygen saturation (SpO2; pulse oximeter) and beat-to-beat blood pressure (finometer) were measured continuously at rest and during exercise. Data are mean ± SD and group differences at peak power output were analyzed using independent t-tests, with significance set at p<0.05. RESULTS: At 5000 m, resting measures of SpO2 between losartan and placebo groups were not significantly different (79 ± 5 vs. 76 ± 6%, p=0.40). Peak power was similarly reduced relative to sea level (p<0.01) in both groups (down 100 ± 29 vs. 91 ± 28 W, p=0.55), while SaO2 (70 ± 6 vs. 70 ± 5%, p=0.96), VO2peak (31.3 ± 4.6 vs. 34.0 ± 7.2 mL·kg-1·min-1, p=0.35), VE (142 ± 38 vs 146.2 ± 31.2 L·min-1, p=0.81) and HR (146 ± 21 vs 149 ± 24 b·min-1, p=0.78) were similar between groups at peak power, as was the increase in BP from rest to peak power (increased by 31 ± 17 vs. 25 ± 16 mmHg, p=0.71). CONCLUSION: Losartan (100 mg) taken daily for 21 days had no observable effect on exercise performance at 5000 m.

Saving energy in residential and commercial buildings is of great interest due to diminishing resources. Heating ventilation and air conditioning systems, and electric lighting are responsible for a significant share of energy usage, which makes it desirable to optimise their operations while maintaining user comfort. Such optimisation requires accurate occupancy estimations. In contrast to current, often invasive or unreliable methods we present an approach for accurate occupancy estimation using a wireless sensor network (WSN) that only collects non-sensitive data and a novel, hierarchical analysis method. We integrate potentially uncertain contextual information to produce occupancy estimates at different levels of granularity and provide confidence measures for effective building management. We evaluate our framework in real-world deployments and demonstrate its effectiveness and accuracy for occupancy monitoring in both low- and high-traffic area scenarios. Furthermore, we show how the system is used for analysing historical data and identify effective room misuse and thus a potential for energy saving.

Health and well-being of dogs, either domesticated pets or service animals, are major concerns that are taken seriously for ethical, emotional, and financial reasons. Welfare assessments in dogs rely on objective observations of both frequency and variability of individual behaviour traits, which is often difficult to obtain in a dog's everyday life. In this paper we have identified a set of activities, which are linked to behaviour traits that are relevant for a dog's wellbeing. We developed a collar-worn accelerometry platform that records dog behaviours in naturalistic environments. A statistical classification framework is used for recognising dog activities. In an experimental evaluation we analysed the naturalistic behaviour of 18 dogs and were able to recognise a total of 17 different activities with approximately 70% classification accuracy. The presented system is the first of its kind that allows for robust and detailed analysis of dog activities in naturalistic environments.