Convulsive seizure detection using a wrist-worn electrodermal activity and accelerometry biosensor

The special requirements for a seizure detector suitable for everyday use in terms of cost, comfort, and social acceptance call for alternatives to electroencephalography (EEG)–based methods. Therefore, we developed an algorithm for automatic detection of generalized tonic–clonic (GTC) seizures based on sympathetically mediated electrodermal activity (EDA) and accelerometry measured using a novel wrist‐worn biosensor. The problem of GTC seizure detection was posed as a supervised learning task in which the goal was to classify 10‐s epochs as a seizure or nonseizure event based on 19 extracted features from EDA and accelerometry recordings using a Support Vector Machine. Performance was evaluated using a double cross‐validation method. The new seizure detection algorithm was tested on >4,213 h of recordings from 80 patients and detected 15 (94%) of 16 of the GTC seizures from seven patients with 130 false alarms (0.74 per 24 h). This algorithm can potentially provide a convulsive seizure alarm system for caregivers and objective quantification of seizure frequency.     

Assessing the association between urban features and human physiological stress response using wearable sensors in different urban contexts

Public open space (POS) plays a significant role in fostering human health and wellbeing in cities. A major limitation of current research on POS and health is that there is little attention on the role of various urban features on people's mental health, in different urban context. This study employed wearable sensors (a wearable camera, Empatica 4 wristband and a GPS device) to measure human physiological responses to urban indicators, objectively. To do this, we selected six kinds of public open space (water area, transit area, green area, commercial area, motor traffic area and mixed office and residential area) and recruited 86 participants for an experimental study. Next, we detected urban features by using Microsoft Cognitive Services (MCS) and calculated a change score to assess human physiological stress responses based on galvanic skin response (GSR) and skin temperature from the wristband. Lastly, we applied random effect model and geographically weighted regression analysis to examine the relationship between urban indicators and human physiological stress responses. The findings show that urban flow (vehicles, bikes and people), waterbodies, greenery and places to sit are associated with the changes of human physiological stress response. The findings indicate that the type of urban context may confound the effect of green and blue urban features; i.e., the effect on physiological stress response can be positive or negative depending on the context. The paper highlights the relevance of considering urban context in research on associations between urban features and stress response.     

Accuracy of vital parameters measured by a wearable patch following major abdominal cancer surgery

IntroductionRecent advances in wearable technology allow for the development of wirelessly connected sensors to continuously measure vital parameters in the general ward or even at home. The present study assesses the accuracy of a wearable patch (Healthdot) for continuous monitoring of heartrate (HR) and respiration rate (RR).Materials and methodsThe Healthdot measures HR and RR by means of chest accelerometry. The study population consisted of patients following major abdominal oncological surgery. The analysis focused on the agreement between HR and RR measured by the Healthdot and the gold standard patient monitor in the intensive and post-anesthesia care unit.ResultsFor HR, a total of 112 h of measurements was collected in 26 patients. For RR, a total of 102 h of measurements was collected in 21 patients. On second to second analysis, 97% of the HR and 87% of the RR measurements were within 5 bpm and 3 rpm of the reference monitor. Assessment of 5-min averaged data resulted in 96% of the HR and 95% of the RR measurements within 5 bpm and 3 rpm of the reference monitor. A Clarke error grid analysis showed that 100% of the HR and 99.4% of the 5-min averaged data was clinically acceptable.ConclusionThe Healthdot accurately measured HR and RR in a cohort of patients recovering from major abdominal surgery, provided that good quality data was obtained. These results push the Healthdot forward as a clinically acceptable tool in low acuity settings for unobtrusive, automatic, wireless and continuous monitoring.     

Technology-based and supervised exercise interventions for individuals with type 2 diabetes: Randomized controlled trial

AimsThe purpose of this study was to estimate, for people with type 2 diabetes (T2D), the extent to which glycemic control was affected by a 12-week program using mobile app and wearable smartwatch in comparison to supervised exercise training.MethodsThis study was a stratified, randomized, assessor-blind, controlled, pragmatic trial with three parallel groups which were supervised, mobile app and wearable smartwatch. Individually tailored exercise regimens delivered through a supervisor, mobile app and wearable smartwatch. Programs consisted of aerobic, resistance exercises, calisthenic, flexibility, balance, and coordination exercises. Primary outcome was change in glycemic control (HbA1c); secondary outcome was Six Minute Walk Test; and explanatory outcomes were exercise behaviour, muscle function, and physical capacity. The groups were contrasted for change in HbA1c and absolute reduction of ≥0.5% (Minimal Important Change). Linear and logistic regressions were used to compare the groups and generalized estimated equations were used to analyze the explanatory outcomes.ResultsIn total, 90 people were randomized, 6 were lost over 12 weeks, leaving 84 with outcome data. The difference in HbA1c did not differ between the supervised and the technology groups combined and between the mobile app and smartwatch group. Proportions of people achieving a clinically meaningful difference on HbA1c between the supervised and technology groups were similar (46% vs 43%) and the associated OR was 0.87 (95%CI:0.34?2.28). Within the two technology groups, proportions of people achieving a clinically meaningful difference in HbA1c were 48% in the mobile app and 38% in the smartwatch groups and the associated OR was 0.65 (95%CI:0.21?2.03). The groups did not differ on secondary and explanatory outcomes.ConclusionsThe results of our trial provide evidence that all outcomes have improved in all groups regardless of the exercise delivery method. Considering the supervised programs are not available for everybody, technological options are crucial to implement to help individuals self-manage most aspects of their diabetes.     

Effect of night-time data on sedentary and upright time and energy expenditure measured with the Fibion accelerometer in Emirati women

Background and aimsWearing an accelerometer during night-time could conflate sedentary behavior time and sleep hours. It is important to assess the impact of including night-time data on sedentary and upright behavior in a sedentary population. Therefore, we investigated differences in sitting and upright time and associated energy expenditure (EE), recorded by a Fibion accelerometer, with and without night-time data in Emirati women working in desk-based jobs.MethodsThirty-one healthy Emirati women working in the government offices used the Fibion accelerometer for a week. Fibion data were included if the participants wore the device for ≥600 min per day for a minimum of three weekdays and one weekend day. Sedentary (sitting) and upright time and associated energy expenditure (EE) were recorded using the Fibion. Variables were compared with and without night-time data using the paired t tests or Wilcoxon signed-rank tests. Effect sizes were determined using Cohen's d.ResultsStatistically significant differences for 15 out of 18 variables were observed when the night-time data were included. Except for cycling time, cycling EE, and vigorous activity time, nearly all other outcome measures showed a significant increase (moderate to large effect sizes) with night-time data compared to those without night-time data.ConclusionsCycling time/EE and vigorous activity time did not change with standard night-time data. Therefore, studies examining only cycling and/or vigorous activity time with the Fibion accelerometer do not require night-time data removal. An analysis of other variables relating to sedentary and upright time will require night-time data exclusion.     

Validation of shoe-worn Gait Up Physilog®5 wearable inertial sensors in adolescents

BackgroundGait Up Physilog® wearable inertial sensors are a powerful alternative to traditional laboratory-based gait assessment for children with gait impairment. To build clinician trust in these devices and ultimately facilitate their use outside confined spaces, studies have examined performance of previous versions of Physilog® wearable inertial sensors but predominant focus has been on older adults. Despite their different gait patterns and behavioural/cognitive profiles, there are limited studies in children.Research questionTo determine whether key spatiotemporal gait parameters (stride length, time and velocity) collected by shoe-worn Physilog®5 sensors in a hallway assessment protocol are a valid method of gait assessment in typically developing adolescents aged 12–15 years.MethodsA total 30 typically developing participants (50 % female) median age 13.7 (interquartile range 2.34) were assessed in an exploratory study whilst walking at self-selected speed over the GAITRite® electronic walkway, concurrently wearing Physilog®5 sensors. Concurrent validity was analysed by Lin’s concordance correlation coefficient (CCC), Bland-Altman plots and 95 % limit of agreement. Systematic bias was assessed using 95 % confidence interval of the mean difference.ResultsMean stride data demonstrated substantial agreement for stride length (CCC = 0.975) and stride velocity (CCC = 0.979) to almost perfect agreement for stride time (CCC > 0.996). Agreement between the technologies for individual stride-to-stride data remained high for stride time (CCC = 0.952); yet reduced for stride length (CCC = 0.868) and stride velocity (CCC = 0.877). Male/female differences in performance of the technology were observed for stride velocity, favouring females.SignificancePhysilog®5 inertial sensors accurately measure walking in adolescents, with stride time the most accurately detected parameter. This demonstrates that wearables can be used by researchers and clinicians working with adolescent groups as an alternative to fixed systems. These findings will ultimately pave the way to using wearables for assessments with children outside of the laboratory environment.     

Reliability and validity of the Stryd Power Meter during different walking conditions

BackgroundThe Styrd Power Meter is gaining special interest for on-field gait analyses due to its low-cost and general availability. However, the reliability and validity of the Stryd during walking on positive slopes using different backpack loads have never been investigated.Research questionIs the Stryd Power Meter reliable and valid for quantifying gait mechanics during walking on positive inclines and during level walking incorporating load carriage?MethodsSeventeen participants from a police force rescue team performed 8 submaximal walking trials for 5-min at 3.6 km·h⁻¹ during different positive slope (1%, 10% and 20%) and backpack load (0%, 10%, 20%, 30% and 40% of body mass) conditions. Two Stryd devices were utilized for reliability analyses. Validity of cadence and ground contact time (GCT) were analyzed against a gold standard device (Optojump).ResultsThe Stryd demonstrated acceptable reliability [mean bias: < 2.5%; effect size (ES): < 0.25; standard error of the mean: < 1.7%; r: > 0.76] for power, cadence, and GCT. Validity measures (mean bias: <0.8%; ES: <0.07; r: >0.96; Lin’s Concordance Coefficient: 0.96; Mean Absolute Percent Error: <1%) for cadence were also found to be acceptable. The Stryd overestimated (P < 0.001; ES: >5.1) GCT in all the walking conditions. A significant systematic positive bias (P < 0.022; r = 0.56–0.76) was found in 7 conditions.Significance: The Stryd Power Meter appears to produce reliable measurements for power output, cadence and GCT. The Stryd produced valid measurements for cadence during walking on positive slopes and during level walking with a loaded backpack. However, the Stryd is not valid for measuring GCT during these walking conditions. This study adds novel data regarding the reliability and validity of this device and might be of particular interest for scientists, practitioners, and first responders seeking reliable devices to quantify gait mechanics during walking.     

Changes in daily energy expenditure and movement behavior in unilateral vestibular hypofunction: Relationships with neuro-otological parameters

The vestibular system has been found to affect energy homeostasis and body composition, due to its extensive connections to the brainstem and melanocortin nuclei involved in regulating the metabolism and feeding behavior. The aim of this study was to evaluate – by means of a wrist-worn physical activity tracker and bioelectrical impedance analysis (BIA) – the energy expenditure (EE) in resting (REE) and free-living conditions and movement behavior in a group of chronic unilateral vestibular hypofunction (UVH) patients when compared with a control group (CG) of healthy participants. Forty-six chronic UVH and 60 CG participants underwent otoneurological (including video-Head Impulse Test [vHIT] for studying vestibulo-ocular reflex [VOR] and static posturography testing [SPT]), and EE and movement measurements and self–report (SRM) and performance measures (PM). As well as significant (p < 0.001) changes in SPT variables (area and path length) and SRM/PM, UVH participants also demonstrated significantly (p < 0.001) lower values in REE, movement EE, hours/day spent upright, number of strides and distance covered and total daily EE (p = 0.007) compared to the CG. UVH patients consumed significantly lower Kcal/min in sweeping (p = 0.001) and walking upstairs and downstairs (p < 0.001) compared to the CG. Multiple correlations were found between free-living and resting EE and neuro-otological parameters in UVH participants. Since the melanocortin system could be affected along the central vestibular pathways as a consequence of chronic vestibular deafferentation, data collected by reliable wearables could reflect the phenomena that constitute an increased risk of falls and sedentary lifestyle for patients affected by UVH, and could improve rehabilitation stages.