Instrumented Pre-Hospital Care Simulation Mannequin for Use in Spinal Motion Restrictions Scenarios: Validation of Cervical and Lumbar Motion Assessment.

BACKGROUND: A mid-fidelity simulation mannequin, equipped with an instrumented cervical and lumbar spine, was developed to investigate best practices and train healthcare professionals in applying spinal motion restrictions (SMRs) during the early mobilization and transfer of accident victims with suspected spine injury. The study objectives are to (1) examine accuracy of the cervical and lumbar motions measured with the mannequin; and (2) confirm that the speed of motion has no bearing on this accuracy. METHODS: Accuracy was evaluated by concurrently comparing the orientation data obtained with the mannequin with that from an optoelectronic system. The mannequin's head and pelvis were moved in all anatomical planes of motion at different speeds. RESULTS: Accuracy, assessed by root-mean-square error, varied between 0.7° and 1.5° in all anatomical planes of motion. Bland-Altman analysis revealed a bias ranging from -0.7° to 0.6°, with the absolute limit of agreement remaining below 3.5°. The minimal detectable change varied between 1.3° and 2.6°. Motion speed demonstrated no impact on accuracy. CONCLUSIONS: The results of this validation study confirm the mannequin's potential to provide accurate measurements of cervical and lumbar motion during simulation scenarios for training and research on the application of SMR.

Removal of the cervical collar from alpine rescue protocols? A biomechanical non-inferiority trial in real-life mountain conditions.

BACKGROUND: Alpine skiing rescues are challenging because of the mountainous environment and risks of cervical spine motion (CSM) induced during victims' extrications (EXs) and downhill evacuations (DEs). The benefits of applying a cervical collar (CC) over manual in-line stabilization without CC (MILS) in terms of spinal motion restriction during simulated alpine rescues are undocumented. Our hypothesis was that CSM recorded using MILS alone is non-inferior to CSM recorded with a CC according to a 10 degrees margin. METHODS: A total of 32 alpine extrications and 4 downhill evacuations on different slope conditions were performed using a high fidelity mannequin designed with a motion sensors instrumented cervical spine. The primary outcome was the peak extrication 3D excursion angle (Peak 3D θEX,) of the mannequin's head. The secondary objectives were to describe the time to extrication completion (tEX) and to highlight which extrication manipulation is more likely to induce CSM. RESULTS: The median Peak 3D θEX recorded during flat terrain extrications using CC was 10.77° (95% CI 7.31°-16.45°) compared to 13.06° (95% CI 10.20°-30.36°) using MILS, and 16.09° (95% CI 9.07°-37.43°) for CC versus 16.65° (95% CI 13.80°-23.40°) using MILS on a steep slope. Peak 3D θEX with CC or using MILS during extrications were equivalent according to a 10 degrees non-inferiority hypothesis testing (p < 0.05). Time to extrication completion (tEX) was significantly reduced using MILS without CC on a flat terrain with a median duration of 237,3 s (95% CI 197.8 s, 272.2 s) compared to 358.7 s (95% CI 324.1 s, 472.4 s). During downhill evacuations, CSM with and without CC across all terrain conditions were negligible (< 5°). When CC is used; its installation manipulation induces the highest CSM. When EXs are done using MILS without CC, the logroll initiation is the manipulation inducing the highest risk of CSM. CONCLUSION: For experienced ski patrollers, the biomechanical benefits of spinal motion restriction provided by CC over MILS during alpine skiing rescues appear to be marginal and CC use negatively affects rescue time.

OpenTera: A microservice architecture solution for rapid prototyping of robotic solutions to COVID-19 challenges in care facilities.

As telecommunications technology progresses, telehealth frameworks are becoming more widely adopted in the context of long-term care (LTC) for older adults, both in care facilities and in homes. Today, robots could assist healthcare workers when they provide care to elderly patients, who constitute a particularly vulnerable population during the COVID-19 pandemic. Previous work on user-centered design of assistive technologies in LTC facilities for seniors has identified positive impacts. The need to deal with the effects of the COVID-19 pandemic emphasizes the benefits of this approach, but also highlights some new challenges for which robots could be interesting solutions to be deployed in LTC facilities. This requires customization of telecommunication and audio/video/data processing to address specific clinical requirements and needs. This paper presents OpenTera, an open source telehealth framework, aiming to facilitate prototyping of such solutions by software and robotic designers. Designed as a microservice-oriented platform, OpenTera is an end-to-end solution that employs a series of independent modules for tasks such as data and session management, telehealth, daily assistive tasks/actions, together with smart devices and environments, all connected through the framework. After explaining the framework, we illustrate how OpenTera can be used to implement robotic solutions for different applications identified in LTC facilities and homes, and we describe how we plan to validate them through field trials.

Force applied to a grab bar during bathtub transfers.

BACKGROUND: Grab bars are a common fall prevention strategy in the bathroom, but biomechanical data are lacking to support clinicians' interventions. This study aims to determine the magnitude and duration of the force applied to four grab bar configurations during complete bathtub transfers on a potentially slippery surface. METHODS: A three factorial repeated measures design was used in an experimental environment including a bathtub, padded walls, instrumented fixed grab bars and a safety harness. Seven healthy young adults stepped into the bathtub, sat down at the bottom, stood up and stepped out (three trials), with or without a slippery surface, grabbing onto four grab bar configurations (vertical, angled, horizontal low, horizontal high). Maximum force magnitudes and durations during bathtub transfers were measured by two 6-degrees of freedom load cells. FINDINGS: On average, 23.2 ± 6.4% of body weight was applied on the grab bar during complete bathtub transfers. Maximum resultant forces were not influenced by grab bar configuration, presence of a slippery surface, or direction of bathtub transfer (entrance or exit), except for the vertical configuration without a slippery surface where the maximum resultant force was smaller than for the three other configurations. Transferring on a slippery surface increased the time participants applied force on the grab bars. INTERPRETATION: Grab bars used during complete bathtub transfers with no loss of balance should be capable of sustaining a minimum of 23.2% of body weight, to which a factor of safety of 1.5 should be added, regardless of the grab bar configuration.

Characteristics of Lower Limb Muscle Strength, Balance, Mobility, and Function in Older Women with Urge and Mixed Urinary Incontinence: An Observational Pilot Study.

Purpose: After the age of 65, urinary incontinence (UI) occurs in one of every two women. A positive correlation between falls and urgency UI (UUI) or mixed UI (MUI) has also been identified. However, lower extremity impairments in older women with UUI or MUI have not been thoroughly investigated. The primary goal of this study was to compare lower limb strength, balance, mobility, and function in older women with and without UUI or MUI. The secondary goal was to evaluate the association between these measurements and UI severity. Method: A total of 40 older women with and without UUI or MUI completed standardized tests for lower limb strength (knee flexor or extensor dynamometry, 30-second sit-to-stand test), balance (single-leg stance test, Four Square Step Test, Activities-specific Balance Confidence questionnaire), mobility (10-metre walk test, 6-minute walk test), and function (Human Activity Profile questionnaire, 12-Item Short Form Health Survey). Results: Significant differences in balance and mobility were observed between the two groups. Women with UI had shorter single-leg stance times, lower balance confidence scores, and slower gait speeds. Conclusions: The results from this pilot study suggest that high-functioning older women with UUI or MUI have balance and mobility impairments. More studies are needed to confirm these results. By reporting power calculations for sample size, this pilot study provides a useful basis on which to design and conduct larger studies.

Objectif : après l'âge de 65 ans, une femme sur deux souffre d'incontinence urinaire (IU). On constate également une corrélation entre les chutes et l'incontinence par urgenturie (IUU) ou l'incontinence urinaire mixte (IUM). Cependant, les déficiences des membres inférieurs chez les femmes âgées qui souffrent d'IUU ou d'IUM n'ont pas fait l'objet d'études approfondies. La présente étude avait comme principal objectif de comparer la force des membres inférieurs, l'équilibre, la mobilité et la fonction générale des femmes âgées présentant ou non une IUU ou une IUM. L'objectif secondaire consistait à évaluer l'association entre ces mesures et la gravité de l'IU. Méthodologie : au total, 40 femmes âgées présentant ou non une IUU ou une IUM ont effectué des tests standardisés pour mesurer la force de leurs membres inférieurs (mesure dynamométrique de flexion et d'extension du genou, test assis-debout de 30 secondes), leur équilibre (test d'équilibre unipodal, et Four Square Step Test, questionnaire sur la confiance en leur équilibre Activities-Specific Balance Confidence scale), leur mobilité (test de marche sur 10 mètres, test de marche de six minutes) et leur fonction (Human Activity Profile questionnaire, 12-Item Short Form Health Survey). Résultats : les chercheurs ont observé des différences d'équilibre et de mobilité importantes entre les deux groupes. Les femmes ayant une IU ont obtenu des temps réduits au test d'équilibre unipodal, présentaient des scores de confiance en leur équilibre plus bas ainsi qu'une vitesse de marche réduite. Conclusion : d'après les résultats de ce projet pilote, on constate des problèmes d'équilibre et de mobilité chez les femmes âgées hautement fonctionnelles qui présentent une IUU ou une IUM. D'autres d'études sont nécessaires pour confirmer ces résultats. En rendant compte des calculs de puissance de taille échantillonnale, le présent projet pilote représente un point de départ utile pour concevoir et réaliser des études plus vastes.

Wireless measurement of rectal temperature during exercise: Comparing an ingestible thermometric telemetric pill used as a suppository against a conventional rectal probe.

Wireless measurement of rectal temperature during exercise may circumvent some limitations associated with the use of a conventional wired probe. We determined, for the first time, whether temperatures provided in vivo by wireless ingestible thermometric telemetric pills and a rectal probe compare favorably under conditions producing slow and rapid increases and decreases in rectal temperature. While wearing a rectal probe linked to a wireless ingestible thermometric telemetric pill, 13 participants completed the following phases: 1) 30 min sitting; 2) 45 min passive heat exposure (40-42 °C); 3) 45 min sitting while ingesting 7.5 g of ice slurry · kg body mass-1; 4) running exercise (38 °C) at 68% V˙O2max until a 39.5 °C increase in rectal probe temperature and; 5) cold-water (10 °C) immersion until a 1.5 °C decrease in rectal probe temperature. Acceptable differences between devices were taken as ≤ 0.3 °C. Mean differences within phases were all < 0.3 °C, whereas 95% limits of agreement ranged from ±0.2 °C to ±0.4 °C, coefficient of variations from ±0.3% to ±0.6% and typical error of measurements from ±0.1 °C to ±0.2°. Of the 14881 rectal temperature values measured over the experiment with the wireless ingestible thermometric telemetric pills and rectal probe, 91% of the differences between devices were found to be ≤ 0.3 °C. Results suggest that rectal temperatures provided by a wireless ingestible thermometric telemetric pill used as a suppository agree with those of a conventional wired probe. Hence, rectal temperature can reliably be measured using a wireless ingestible thermometric telemetric pill as a suppository.

Pilot study of EEG in neonates born to mothers with gestational diabetes mellitus.

BACKGROUND: The goal was to evaluate whether there was neurodevelopmental deficits in newborns born to mothers with gestational diabetes mellitus (GDM) compared to control newborns born to healthy mothers. METHODS: Forty-six pregnant women (21 controls and 25 GDM) were recruited. Electroencephalogram (EEG) was recorded in the newborns within 48 h after birth. The EEG signal was quantitatively analyzed using power spectral density (PSD); coherence between hemispheres was calculated in paired channels of frontal, temporal, central and occipital regions. RESULTS: The left centro-occipital PSD in control newborns was 12% higher than in GDM newborns (p = 0.036) but was not significant after adjustment for gestational age. While coherence was higher in the frontal regions compared to the occipital regions (p < 0.001), there was no difference between the groups for the fronto-temporal, frontal-central, centro-occipital and tempo-occipital regions. CONCLUSION: Our results support that EEG differences between groups were mainly modified by gestational age and less by GDM status of the mothers. However, there is a need to confirm this result with a higher number of mother-newborns. Quantitative EEG in GDM newborns within 48 h after birth is feasible. This study emphasizes the importance of controlling blood glucose during GDM to protect infant brain development.

Camera pose estimation to improve accuracy and reliability of joint angles assessed with attitude and heading reference systems.

Joint kinematics can be assessed using orientation estimates from Attitude and Heading Reference Systems (AHRS). However, magnetically-perturbed environments affect the accuracy of the estimated orientations. This study investigates, both in controlled and human mobility conditions, a trial calibration technic based on a 2D photograph with a pose estimation algorithm to correct initial difference in AHRS Inertial reference frames and improve joint angle accuracy. In controlled conditions, two AHRS were solidly affixed onto a wooden stick and a series of static and dynamic trials were performed in varying environments. Mean accuracy of relative orientation between the two AHRS was improved from 24.4° to 2.9° using the proposed correction method. In human conditions, AHRS were placed on the shank and the foot of a participant who performed repeated trials of straight walking and walking while turning, varying the level of magnetic perturbation in the starting environment and the walking speed. Mean joint orientation accuracy went from 6.7° to 2.8° using the correction algorithm. The impact of starting environment was also greatly reduced, up to a point where one could consider it as non-significant from a clinical point of view (maximum mean difference went from 8° to 0.6°). The results obtained demonstrate that the proposed method improves significantly the mean accuracy of AHRS joint orientation estimations in magnetically-perturbed environments and can be implemented in post processing of AHRS data collected during biomechanical evaluation of motion.

Telehomecare telecommunication framework - from remote patient monitoring to video visits and robot telepresence.

Over the last few years, the number of remote patient monitoring (RPM) products and of videoconferencing systems has exploded. There is also a significant number of research initiatives addressing the use of service robots for assistance in daily living activities. From a technological standpoint, providing telehomecare services is certainly feasible. However, one technological barrier is to have access to a telecommunication platform that can be adapted to address the broad range of specifications and requirements of clinical and telehealth applications. Handling the full spectrum of possibilities requires a telecommunication framework that can transmit vital sign data from patients to clinicians, bidirectional audio-video from a standard computing device, and also multiple video streams and bidirectional transmission of control data. This paper presents a framework that integrates such capabilities. It also illustrates the versatility of the framework by presenting custom-designed devices allowing integration of capabilities ranging from RPM to video visits and robot telepresence.

Exerciser for rehabilitation of the Arm (ERA): Development and unique features of a 3D end-effector robot.

Stroke is one of the leading causes of disability worldwide. Consequently, many stroke survivors exhibit difficulties undergoing voluntary movement in their affected upper limb, compromising their functional performance and level of independence. To minimize the negative impact of stroke disabilities, exercises are recognized as a key element in post-stroke rehabilitation. In order to provide the practice of exercises in a uniform and controlled manner as well as increasing the efficiency of therapists' interventions, robotic training has been found, and continues to prove itself, as an innovative intervention for post-stroke rehabilitation. However, the complexity as well as the limited degrees of freedom and workspace of currently commercially available robots can limit their use in clinical settings. Up to now, user-friendly robots covering a sufficiently large workspace for training of the upper limb in its full range of motion are lacking. This paper presents the design and implementation of ERA, an upper-limb 3-DOF force-controlled exerciser robot, which presents a workspace covering the entire range of motion of the upper limb. The ERA robot provides 3D reaching movements in a haptic virtual environment. A description of the hardware and software components of the ERA robot is also presented along with a demonstration of its capabilities in one of the three operational modes that were developed.

Inertial measures of motion for clinical biomechanics: comparative assessment of accuracy under controlled conditions - changes in accuracy over time.

BACKGROUND: Interest in 3D inertial motion tracking devices (AHRS) has been growing rapidly among the biomechanical community. Although the convenience of such tracking devices seems to open a whole new world of possibilities for evaluation in clinical biomechanics, its limitations haven't been extensively documented. The objectives of this study are: 1) to assess the change in absolute and relative accuracy of multiple units of 3 commercially available AHRS over time; and 2) to identify different sources of errors affecting AHRS accuracy and to document how they may affect the measurements over time. METHODS: This study used an instrumented Gimbal table on which AHRS modules were carefully attached and put through a series of velocity-controlled sustained motions including 2 minutes motion trials (2MT) and 12 minutes multiple dynamic phases motion trials (12MDP). Absolute accuracy was assessed by comparison of the AHRS orientation measurements to those of an optical gold standard. Relative accuracy was evaluated using the variation in relative orientation between modules during the trials. FINDINGS: Both absolute and relative accuracy decreased over time during 2MT. 12MDP trials showed a significant decrease in accuracy over multiple phases, but accuracy could be enhanced significantly by resetting the reference point and/or compensating for initial Inertial frame estimation reference for each phase. INTERPRETATION: The variation in AHRS accuracy observed between the different systems and with time can be attributed in part to the dynamic estimation error, but also and foremost, to the ability of AHRS units to locate the same Inertial frame. CONCLUSIONS: Mean accuracies obtained under the Gimbal table sustained conditions of motion suggest that AHRS are promising tools for clinical mobility assessment under constrained conditions of use. However, improvement in magnetic compensation and alignment between AHRS modules are desirable in order for AHRS to reach their full potential in capturing clinical outcomes.

Effects of Right Lower Limb Orthopedic Immobilization on Braking Function: An On-The-Road Experimental Study With Healthy Volunteers.

Little is known about how immobilization of the right lower limb might affect driving. The purpose of the present study was to evaluate the effect of 2 types of immobilization on the emergency braking time of healthy subjects during actual driving conditions. The emergency braking times of 14 healthy volunteers were assessed in a closed circuit under 3 conditions: wearing running shoes, wearing an Aircast Walker(®), or wearing a walking cast on their right lower limb. An instrumented car was used to measure the emergency braking times during braking tests with and without a distractor. The foot movement times were significantly increased with both immobilization devices compared with the running shoe (p < .01). The median total braking time with the running shoe during emergency braking without a distractor was 0.452 (interquartile range, 25th to 75th [IQR], 0.413 to 0.472) second. The results obtained with the Aircast Walker(®) or the walking cast were significantly longer (p < .01), at 0.480 (IQR, 0.431 to 0.537) second and 0.512 (IQR, 0.451 to 0.535) second, respectively. When a distractor was added, the total braking time with the running shoe, Aircast Walker(®), and walking cast was 0.489 (IQR, 0.429 to 0.575), 0.516 (IQR, 0.459 to 0.586), and 0.510 (IQR, 0.469 to 0.570) second, respectively, with no statistically significant differences among these 3 conditions. Wearing an immobilization device on the right lower limb minimally lengthens the emergency braking time in healthy drivers under actual driving conditions. Clinicians must nonetheless exercise caution when advising a driver wearing an orthopedic immobilization, because driving a motor vehicle is a complex psychomotor task that goes well beyond the emergency braking time.

Inertial measures of motion for clinical biomechanics: comparative assessment of accuracy under controlled conditions - effect of velocity.

BACKGROUND: Inertial measurement of motion with Attitude and Heading Reference Systems (AHRS) is emerging as an alternative to 3D motion capture systems in biomechanics. The objectives of this study are: 1) to describe the absolute and relative accuracy of multiple units of commercially available AHRS under various types of motion; and 2) to evaluate the effect of motion velocity on the accuracy of these measurements. METHODS: The criterion validity of accuracy was established under controlled conditions using an instrumented Gimbal table. AHRS modules were carefully attached to the center plate of the Gimbal table and put through experimental static and dynamic conditions. Static and absolute accuracy was assessed by comparing the AHRS orientation measurement to those obtained using an optical gold standard. Relative accuracy was assessed by measuring the variation in relative orientation between modules during trials. FINDINGS: Evaluated AHRS systems demonstrated good absolute static accuracy (mean error < 0.5(o)) and clinically acceptable absolute accuracy under condition of slow motions (mean error between 0.5(o) and 3.1(o)). In slow motions, relative accuracy varied from 2(o) to 7(o) depending on the type of AHRS and the type of rotation. Absolute and relative accuracy were significantly affected (p<0.05) by velocity during sustained motions. The extent of that effect varied across AHRS. INTERPRETATION: Absolute and relative accuracy of AHRS are affected by environmental magnetic perturbations and conditions of motions. Relative accuracy of AHRS is mostly affected by the ability of all modules to locate the same global reference coordinate system at all time. CONCLUSIONS: Existing AHRS systems can be considered for use in clinical biomechanics under constrained conditions of use. While their individual capacity to track absolute motion is relatively consistent, the use of multiple AHRS modules to compute relative motion between rigid bodies needs to be optimized according to the conditions of operation.

Simulated in-home teletreatment for anomia.

This pilot study explored the feasibility of in-home teletreatment for patients with post-stroke anomia. Three participants over 65 years of age suffering from post-stroke anomia were treated in this pre/post-intervention case study. They received 12 speech therapy teletreatments (two sessions/week for 6 weeks) aimed at improving confrontation naming skills. Half of the failed items from a set of 120 preselected stimuli were trained during treatment (Block A-trained stimuli) while the other half served as controls (Block B-untrained stimuli). Variables measured were: 1) efficacy of treatment (performance on Block-A vs. Block B Stimuli), and 2) participants' satisfaction with teletreatment (using a French adaptation of the Telemedicine satisfaction questionnaire). All participants showed a clinically relevant improvement on confrontation naming of trained items and less improvement for untrained items. The researchers also obtained high satisfaction scores on the questionnaire (above 57/60). This pilot study supports the feasibility of speech therapy teletreatments applied to neurological language disorders.

Wireless inertial measurement unit with GPS (WIMU-GPS)--wearable monitoring platform for ecological assessment of lifespace and mobility in aging and disease.

This paper proposes an innovative ambulatory mobility and activity monitoring approach based on a wearable datalogging platform that combines inertial sensing with GPS tracking to assess the lifespace and mobility profile of individuals in their home and community environments. The components, I/O architecture, sensors and functions of the WIMU-GPS are presented. Outcome variables that can be measured with it are described and illustrated. Data on the power usage, operating autonomy of the WIMU-GPS and the GPS tracking performances and time to first fix of the unit are presented. The study of lifespace and mobility with the WIMU-GPS can potentially provide unique insights into intrapersonal and environmental factors contributing to mobility restriction. On-going studies are underway to establish the validity and reliability of the WIMU-GPS in characterizing the lifespace and mobility profile of older adults.

Comparison between younger and older drivers of the effect of obstacle direction on the minimum obstacle distance to brake and avoid a motor vehicle accident.

Our objectives were to determine the effects of age and direction of appearance of an obstacle on the minimum obstacle distance to brake and avoid a motor vehicle accident. Ten younger and 10 older drivers were tested in a custom-made driving simulator using an animation of a straight suburban road. Driving at 50 km/h, participants suddenly encountered pedestrians appearing at increasingly closer distances in front, from the left or from the right. They then had to brake as fast as possible and come to a complete stop before running over the pedestrian. Results showed that older drivers had 1.8m greater minimum obstacle distance than younger drivers. This decreased ability with age appeared to be due to a decline in response initiation. Pedestrians appearing from the periphery also resulted in 2.1m (left) and 2.8m (right) greater minimum obstacle distance than those appearing directly in front. This decreased ability with obstacle direction appeared to be mostly due to declines in response initiation and response geometry. Finally, the difference with age was greater when pedestrians appeared from the right compared to the left or front. Therefore, it is important to include both temporal and geometrical performance measures in studies on motor vehicle accidents.

Effects of orthopaedic immobilization of the right lower limb on driving performance: an experimental study during simulated driving by healthy volunteers.

BACKGROUND: The effects of immobilization of the right lower limb on driving performance are unknown. Therefore, clinicians and legislators cannot put forth recommendations for road safety for patients requiring such immobilization. The objective of the present study was to evaluate the effect of two orthopaedic immobilization devices on the braking performances of healthy volunteers under simulated driving conditions. METHODS: The braking performances of forty-eight healthy volunteers were evaluated under three conditions: wearing a running shoe, wearing a walking cast, and wearing an Aircast Walker on the right lower limb. A computerized driving simulator was used to measure the maximum force applied on the brake pedal during braking as well as the braking reaction time and the total braking time during emergency braking with and without a distractor. RESULTS: The mean braking forces applied with the shoe, the walking cast, and the Aircast Walker were 293.8, 275.4, and 287.2 lb (133.3, 124.9, and 130.3 kg), respectively. The value with the walking cast was significantly lower than that with the shoe or Aircast Walker (p < 0.0001); there was no difference between the shoe and the Aircast Walker. The adjusted mean braking reaction times during emergency braking without a distractor were 0.580 second (shoe), 0.609 second (cast), and 0.619 second (Aircast Walker). The value with the running shoe was significantly lower than that with either type of immobilization (p < or = 0.0001). With a distractor, the mean braking reaction time was shorter with the running shoe than it was with either form of immobilization (p < or = 0.0001); the mean time was also shorter with the walking cast than it was with the Aircast Walker (p = 0.003). During both emergency braking tasks (with and without a distractor), the mean total braking time was shorter with the shoe than it was with either type of immobilization (p < 0.0001). With a distractor, the adjusted mean total braking time was shorter with the walking cast than it was with the Aircast Walker (p = 0.035). CONCLUSIONS: Immobilization of the right lower limb affects the braking force as well as the braking reaction time and total braking time during emergency braking by healthy volunteers. While these changes are significant, their impact on the ability to drive safely during emergency braking situations is questionable. Future research into the impact of such immobilization on the emergency braking performances of patients is warranted to confirm these observations.

Accelerometer-based wireless body area network to estimate intensity of therapy in post-acute rehabilitation.

BACKGROUND: It has been suggested that there is a dose-response relationship between the amount of therapy and functional recovery in post-acute rehabilitation care. To this day, only the total time of therapy has been investigated as a potential determinant of this dose-response relationship because of methodological and measurement challenges. The primary objective of this study was to compare time and motion measures during real life physical therapy with estimates of active time (i.e. the time during which a patient is active physically) obtained with a wireless body area network (WBAN) of 3D accelerometer modules positioned at the hip, wrist and ankle. The secondary objective was to assess the differences in estimates of active time when using a single accelerometer module positioned at the hip. METHODS: Five patients (77.4 +/- 5.2 y) with 4 different admission diagnoses (stroke, lower limb fracture, amputation and immobilization syndrome) were recruited in a post-acute rehabilitation center and observed during their physical therapy sessions throughout their stay. Active time was recorded by a trained observer using a continuous time and motion analysis program running on a Tablet-PC. Two WBAN configurations were used: 1) three accelerometer modules located at the hip, wrist and ankle (M3) and 2) one accelerometer located at the hip (M1). Acceleration signals from the WBANs were synchronized with the observations. Estimates of active time were computed based on the temporal density of the acceleration signals. RESULTS: A total of 62 physical therapy sessions were observed. Strong associations were found between WBANs estimates of active time and time and motion measures of active time. For the combined sessions, the intraclass correlation coefficient (ICC) was 0.93 (P < or = 0.001) for M3 and 0.79 (P < or = 0.001) for M1. The mean percentage of differences between observation measures and estimates from the WBAN of active time was -8.7% +/- 2.0% using data from M3 and -16.4% +/- 10.4% using data from M1. CONCLUSION: WBANs estimates of active time compare favorably with results from observation-based time and motion measures. While the investigation on the association between active time and outcomes of rehabilitation needs to be studied in a larger scale study, the use of an accelerometer-based WBAN to measure active time is a promising approach that offers a better overall precision than methods relying on work sampling. Depending on the accuracy needed, the use of a single accelerometer module positioned on the hip may still be an interesting alternative to using multiple modules.

Assessing control of postural stability in community-living older adults using performance-based limits of stability.

BACKGROUND: Balance disability measurements routinely used to identify fall risks in frail populations have limited value in the early detection of postural stability deficits in community-living older adults. The objectives of the study were to 1) measure performance-based limits of stability (LOS) in community-living older adults and compare them to theoretical LOS computed from data proposed by the Balance Master system, 2) explore the feasibility of a new measurement approach based on the assessment of postural stability during weight-shifting tasks at performance-based LOS, 3) quantify intra-session performance variability during multiple trials using the performance-based LOS paradigm. METHODS: Twenty-four healthy community-living older adults (10 men, 14 women) aged between 62 to 85 (mean age +/- sd, 71.5 +/- 6 yrs) participated in the study. Subjects' performance-based LOS were established by asking them to transfer their body weight as far as possible in three directions (forward, right and left) without changing their base of support. LOS were computed as the maximal excursion of the COP in each direction among three trials. Participants then performed two experimental tasks that consisted in controlling, with the assistance of visual feedback, their centre of pressure (COP) within two predefined targets set at 100% of their performance-based LOS. For each tasks 8 trials were performed. Ground reaction forces and torques during performance-based LOS evaluation and experimental tasks were recorded with a force plate. Sway area and medio-lateral mean COP displacement speed variables were extracted from force plate recordings. RESULTS: Significant differences between theoretical LOS computed from maximum leaning angles derived from anthropometric characteristics and performance-based LOS were observed. Results showed that a motor learning effect was present as the participants optimized their weight-shifting strategy through the first three trials of each task using the visual biofeedback provided on their COP. Reliable measures of control of postural stability at performance-based LOS can be obtained after two additional trials after the learning phase (0.69 > ICC > 1.0). CONCLUSION: Establishing performance-based LOS instead of relying on estimations of theoretical LOS offers a more individualized and realistic insight on the true LOS of an individual. Performance-based LOS can be used as targets during weight-shifting postural tasks with real time visual feedback of the COP displacement to assess postural stability of community-living older adults. In order to obtain reliable results, a learning phase allowing subjects to learn how to control their COP displacement is needed.

User-based motion sensing and fuzzy logic for automated fall detection in older adults.

More than one third of community-dwelling older adults and up to 60% of nursing home residents fall each year, with 10-15% of fallers sustaining a serious injury. Reliable automated fall detection can increase confidence in people with fear of falling, promote active safe living for older adults, and reduce complications from falls. The performance of a 2-stage fall detection algorithm using impact magnitudes and changes in trunk angles derived from user-based motion sensors was evaluated under laboratory conditions. Ten healthy participants were instrumented on the front and side of the trunk with 3D accelerometers. Participants simulated 9 fall conditions and 6 common activities of daily living. Fall conditions were simulated on a protective mattress. The experimental data set comprised 750 events (45 fall events and 30 nonfall events per participant) that were classified by the fall detection algorithm as either a fall or a nonfall using inputs from 3D accelerometers. Significant differences for impacts recorded, trunk angle changes (p<0.01), and detection performances (p<0.05) were found between fall and nonfall conditions. The proposed algorithm detected fall events during simulated fall conditions with a success rate of 93% and a false-positive rate of 29% during nonfall conditions. Despite a slightly superior identification performance for the accelerometer located on the front of the trunk, no significant differences were found between the two motion sensor locations. Automated detection of fall events based on user-based motion sensing and fuzzy logic shows promising results. Additional rules and optimization of the algorithm will be needed to decrease the false-positive rate.