A Preliminary Study on Prediction of Initial Contact Timing During Gait Using LSTM for FES Control

Coordination of fingertip forces in object transport during gait in children with hemiplegic cerebral palsy

"Ankle foot orthoses (AFO’s) are prescribed to patients who have ankle impairments causing difficulty walking following stroke. The evidence regarding the benefit of prescribing AFO’s, particularly with regard to type of AFO and timing of intervention, is unclear. There are few studies that investigate the effect of AFO’s in the subacute phase following stroke and few studies that compare different types of AFO. There is little evidence regarding the effect of AFO’s on the gait of normal healthy individuals. This study aimed to compare the effects on walking in different AFO’s, of varying degrees of rigidity, in participants in the early stages of stroke walking recovery and in healthy individuals. Thirteen participants (ten male) in the subacute phase of stroke recovery, aged 23-71 years (M=52.3+13.9), and thirteen age and gender matched healthy participants, aged 26-70 years (M=52.2 +13.1), were recruited to the study. Stroke participants were included if they had a unilateral hemiparesis, were less than 20 weeks post stroke, able to walk with or without supervision and had a motor deficit of the ankle dorsiflexors. Temporal distance gait measures were collected using the GAITRite mat (CIR Systems GRG-24, United States, 80Hz) and knee angles throughout the stance phase, were collected using Silicon Coach Pro software™ (version 7, Silicon Coach Pty Ltd, Dunedin, New Zealand). Stroke participants were tested across three consecutive days, whilst the healthy participants were tested on a single occasion in barefoot, shoes, and three AFO types of varying rigidity: push aequi brace, spring leaf AFO and in a fibreglass cast Each group of participants were familiarised to walking in each AFO. Group differences across the five conditions were assessed using the Friedman’s Test. The ‘smallest real difference’ measure was used to determine the degree of individual improvement with use of the AFOs compared to the shod walking. The results indicated the healthy participants walking performance exceeded that of the stroke participants for velocity, cadence, double limb support, step length, single support phase, single support symmetry, but not swing phase or knee angle at initial contact, midstance or terminal stance for each of conditions tested. Group analysis demonstrated that use of an AFO did not improve walking for the stroke participants: who walked at 46.0 cm/sec (SD: 25.9) in shoes, compared with 46.9 cm/sec (SD: 24.4) in an AFO (p= 0.507). However it caused deterioration in walking in the healthy participants, as demonstrated by a 11.9cm/sec deterioration in a AFO (120.1cm/sec +14.2) in comparison to shoes (132.0cm/sec +16.1) (p=0.002) with similar deteriorations in cadence (shoe: 113.1 steps/minute +7.1; AFO: 102.2 +30.7; p=0.009), step length (shoe: 69.9cm +7.9; AFO: 66.0 +7.2; p=0.002), single stance phase (shoe: 37.1% +1.3; AFO 36.0 +1.3; p=0.009), swing phase (shoe: 37.2% +1.4; AFO: 37.7 +1.1; p=0.039), stance symmetry (shoe: -0.63 +2.9; AFO: -4.9 +3.1; p=0.004) and knee angle at initial contact (shoe: 1.92 degrees +3.9; AFO:3.6 +2.6; p=0.049). The results demonstrating the more rigid the AFO the greater the deterioration for the healthy participants. The smallest real differences of the stroke group indicated that for five participants at least one type of AFO improved their walking. The findings of this study do not support the routine prescription of AFO’s following stroke to patients with ankle impairment. As the walking of the healthy participants deteriorated, there is the suggestion that the application of an AFO may be detrimental. As AFO’s have been demonstrated to improve walking performance by increasing velocity, step length or affected leg stance percentage of the gait cycle for some participants the prescription of an AFO should not be discounted. Prior to prescription of an AFO to a stroke patient careful assessment should occur. Following the prescription of an AFO ongoing assessment is required to examine whether the AFO yields a benefit. Future research should consider the analysis of individual responses in addition to group analysis."

The aim of this study was to develop and validate an automated accelerometry-based system for estimating initial contact (IC) and terminal contact (TC) timing information from walking patterns of healthy control subjects and transtibial amputees that can be used in daily life with minimal interference of researchers. Subjects were instrumented with two uniaxial accelerometers just below the knee while synchronized ground reaction force (GRF) recordings were used as reference measurements. An automated multiphase algorithm was developed to estimate the time of IC and TC in the acceleration signals of five healthy subjects and two transtibial amputees walking at different walking speeds. The accuracy of the detection algorithm in ten control subjects and eight transtibial amputees indicated mean errors ranging between 0.013 and 0.034 s for the TC and IC timing, with 95 % confidence interval of the individual step errors ranging between -0.062 and 0.115 s. Correlation coefficients between the estimated stance phase duration and GRF data were 0.98 and 0.97 for controls and amputees, respectively. We concluded that IC and TC can be accurately and easily measured using this system in both healthy subjects and transtibial amputees walking at different walking speeds. The system can be used in clinical situations or gait labs as well as during daily life.

The effect of body weight reduction using a lower body positive pressure treadmill on plantar pressure measures while running

This study investigated the changes in running mechanics and spring-mass behavior over a 24-h treadmill run (24TR). Kinematics, kinetics, and spring-mass characteristics of the running step were assessed in 10 experienced ultralong-distance runners before, every 2 h, and after a 24TR using an instrumented treadmill dynamometer. These measurements were performed at 10 km·h, and mechanical parameters were sampled at 1000 Hz for 10 consecutive steps. Contact and aerial times were determined from ground reaction force (GRF) signals and used to compute step frequency. Maximal GRF, loading rate, downward displacement of the center of mass, and leg length change during the support phase were determined and used to compute both vertical and leg stiffness. Subjects' running pattern and spring-mass behavior significantly changed over the 24TR with a 4.9% higher step frequency on average (because of a significantly 4.5% shorter contact time), a lower maximal GRF (by 4.4% on average), a 13.0% lower leg length change during contact, and an increase in both leg and vertical stiffness (+9.9% and +8.6% on average, respectively). Most of these changes were significant from the early phase of the 24TR (fourth to sixth hour of running) and could be speculated as contributing to an overall limitation of the potentially harmful consequences of such a long-duration run on subjects' musculoskeletal system. During a 24TR, the changes in running mechanics and spring-mass behavior show a clear shift toward a higher oscillating frequency and stiffness, along with lower GRF and leg length change (hence a reduced overall eccentric load) during the support phase of running.

Nowadays, healthy individuals are able to undergo genetic testing in order to find out whether or not they will develop defined genetic conditions in the future. Predictive testing, which is commonly performed in cancer genetics, is also available for an increasing number of neurodegenerative disorders. Receiving the news that one will develop a serious and, in the majority of cases, currently non-treatable disease is a life-changing event. The outcome of such predictive testing is therefore full of implications for the individual's psychological well-being and for his or her present and future life. Psychological implications of predictive testing differ with the nature of the result obtained. Independently of the outcome, individuals need time to adjust to the knowledge of their genetic status. Awareness of risk status has a profound impact not only on individuals but also on their families. Members of the family may see their risk change after an individual has had predictive testing. Offspring are among the first concerned by a predictive test outcome. After receiving an unfavourable result, some individuals may ask for predictive testing for their children. However, for an adult onset condition the option to be tested should be left to the children's own discretion once they are able to make an informed decision. It is the individual's responsibility to share the outcome of their test with at-risk relatives but not with other third parties such as employers and insurance companies. Professionals should help identifying the at-risk relatives and emphasise the importance of disclosing genetic information to them. The ethical principles of autonomy and confidentiality deserve a particular attention in the field of predictive testing. A careful forethought before undergoing a genetic test is essential. By providing information and decision-making support, genetic counselling plays an important role in this contemplation process. It is internationally accepted that predictive testing should be performed following structured guidelines. The latter have been inspired from the predictive testing protocol for Huntington's disease (HD) proposed by the UK HD Consortium. It is recommended that the individual attends several counselling sessions before undergoing the test in order to allow adequate preparation. Follow-up and support should be planned in advance and other counselling sessions should be available if the individual asks for it. A multidisciplinary approach to predictive testing which takes the medical, social and psychological aspects of the diseases into account is essential for good practice. A collaboration with neurologists and psychiatrists is therefore essential. Published reports have shown that individuals have gained from this apparently complex procedure. Individuals who have had extensive pre-test counselling cope better with the test results. Data have shown that pre-test emotional state is a predictor of the individual's post-test reaction and therefore the test protocol should include a pre-test assessment of the emotional state of the individual. The new Swiss law (Loi sur l'Analyse Genetique Humaine, LAGH) requires that individuals undergoing predictive testing have access to proper genetic counselling.

Ankle-foot orthoses (AFOs) are orthotic devices supporting movements of ankles of disabled persons for example hemiplegia, polio, peroneal nerve palsy, etc. In our previous research, we developed some kinds of passive controllable AFO which can control ankle torque with Compact Magnetorheological fluid brakes. One of the remarkable key points of its control is damping control at initial contacts. We think that a prediction of the initial contact is effective for its control because the initial contact usually ends very instant moment of about 0.1 s. In this paper, we describe basic control method of our controllable AFO and prediction method of the initial contact for it. Finally, we could predict instant contacts before 0.1 s with the absolute error of 0.020 s.

Innovative approaches are needed to allow for research in the emergency setting while not compromising either the rights or the interests of the subjects enrolled in such research. The emergency consent exception was developed to meet this need. The goal was to describe the timing of initial contact with relatives and the timing of obtaining informed consent for a research study in patients with severe traumatic brain injury. The study was designed as a prospective, observational study of 129 patients enrolled in an emergency study of traumatic brain injury conducted under the emergency consent exception. Detailed descriptive information was collected both about the availability of relatives of patients enrolled in a study of traumatic brain injury to give prospective consent within the time period required for entering the study and about the extent to which they did give prospective consent during that time period. The number of patients with relatives who could be contacted by research staff increased with time after injury, with 3% (95% CI=0 to 6%), 25% (95% CI=18 to 32%), and 43% (95% CI=35 to 52%) having family at 1, 3, and 6 h, respectively postinjury. An additional 15% were available within the next 6 h. The median time after injury to the initial family contact by the research staff was 2.0 h for patients who had relatives already present at the hospital and 5.7 h for patients whose family had already been contacted by the hospital. The percentage of family members actually giving prospective research consent was much smaller; only 18% actually gave prospective consent within 6 h postinjury. The proportion of critically ill patients with family available to give prospective consent for enrollment in emergency research studies depends primarily on the time period allowed for enrollment in the individual study and the length of the transition from initial contact to completed prospective consent. The study was performed in a specific patient population and may not be generalizable to other settings. Careful attention should be paid by investigators and IRBs as to whether the emergency consent exception is really required for a particular study, or whether the study could proceed using only prospective consent with a longer recruitment period, more research sites, and a higher yield of available family members giving prospective consent. Measures that could shorten the time between initial contact and obtaining informed consent (for example, allowing consent over the phone rather than requiring written consent) might decrease the need for the emergency consent exception.

In order to improve the signal detection capability of orthogonal frequency-division multiplexing systems, a signal detection method based on an improved LSTM network for OFDM systems is proposed. The LSTM network is optimized by the Chameleon Swarm Algorithm (CLCSA) with the coupling variance and lens-imaging learning. The signal detection method based on the traditional LSTM network has the problem of a complex manual tuning process and insufficient stability. To solve the above problem, the improved Chameleon Swarm Algorithm is used to optimize the initial hyperparameters of the LSTM network and obtain the optimal hyperparameters. The optimal hyperparameters initialize the CLCSA-LSTM network model and the CLCSA-LSTM network model is trained. Finally, the trained CLCSA-LSTM network model is used for signal detection in the OFDM system. The simulation results show that the signal detection performance of the OFDM receiver has been significantly improved, and the dependence on CP and pilot overhead can be reduced. Under the same channel environment, the proposed method in this paper has better performance than other signal detection methods, and is close to the performance of the MMSE method, but it does not need prior statistical characteristics of the channel, so it is easy to implement.

Multi-segment foot kinematics and ground reaction forces during gait of individuals with plantar fasciitis

Clinician-facilitated cascade testing for hereditary cancer: Effect of race on completion of genetic testing and utilization of cancer surveillance and risk-reducing surgery (426)

Fall detection is one of the most important functions for a healthcare robot system because falls are very dangerous for older people and might lead to death if failed to provide prompt and adequate treatment. In this paper, we propose an efficient fall detection method based on 3-axis accelerometer and depth sensor fusion. LSTM networks are applied to handle temporal information. Simple low-level motion and pose features are obtained from each sensor data, and then fed into the LSTM networks that can learn high-level feature representations to classify falls from other daily life activities. Also, various learning tricks are combined to improve the performance. Experimental results show that the proposed fall detection method outperforms existing methods.

Assuming the ground reaction force of both feet to be the same in the same phase of a stride cycle, we establish the relationships between the time of initial foot contact and the ground reaction force, accele ration, velocity, displacement and average kinetic energy of center of mass. We employ the dispersion to analyze the effect of the time of the initial foot contact that imposes upon these physical quantities. We present results of an analytic and numericalcalculation that studies the relationship between the time of initial foot contact and the ground reaction force of human gait and explores the dynamic principle of center of mass. Our study reveals that when the time of one foot's initial contact falls r ight in the middle of the other foot's stride cycle, these physical quantities reach extrema. An action function has been identified as the dispersion of the physical quantities and optimized analysis used to prove the least -action principle in gait. In ad dition to being very significant to the research domains such as clinical diagnosis, biped robot's gait control,

ABSTRACTAir quality sensors are becoming increasingly available to the general public, providing individuals and communities with information on fine-scale, local air quality in increments as short as 1 min. Current health studies do not support linking 1-min exposures to adverse health effects; therefore, the potential health implications of such ambient exposures are unclear. The U.S. Environmental Protection Agency (EPA) establishes the National Ambient Air Quality Standards (NAAQS) and Air Quality Index (AQI) on the best science available, which typically uses longer averaging periods (e.g., 8 hr; 24 hr). Another consideration for interpreting sensor data is the variable relationship between pollutant concentrations measured by sensors, which are short-term (1 min to 1 hr), and the longer term averages used in the NAAQS and AQI. In addition, sensors often do not meet federal performance or quality assurance requirements, which introduces uncertainty in the accuracy and interpretation of these readings. This article describes a statistical analysis of data from regulatory monitors and new real-time technology from Village Green benches to inform the interpretation and communication of short-term air sensor data. We investigate the characteristics of this novel data set and the temporal relationships of short-term concentrations to 8-hr average (ozone) and 24-hr average (PM2.5) concentrations to examine how sensor readings may relate to the NAAQS and AQI categories, and ultimately to inform breakpoints for sensor messages. We consider the empirical distributions of the maximum 8-hr averages (ozone) and 24-hr averages (PM2.5) given the corresponding short-term concentrations, and provide a probabilistic assessment. The result is a robust, empirical comparison that includes events of interest for air quality exceedances and public health communication. Concentration breakpoints are developed for short-term sensor readings such that, to the extent possible, the related air quality messages that are conveyed to the public are consistent with messages related to the NAAQS and AQI.Implications: Real-time sensors have the potential to provide important information about fine-scale current air quality and local air quality events. The statistical analysis of short-term regulatory and sensor data, coupled with policy considerations and known health effects experienced over longer averaging times, supports interpretation of such short-term data and efforts to communicate local air quality.

Background and Aims Overall, human microbiota contains 1014 bacterial cells. The human intestine is particularly dense of microbes, 1012 bacteria per g (dry weight), especially at colon level. Under healthy conditions, the human microbiota provides trophic and protective functions. Bacteroidaceae, and Prevotellaceae differed among IgA and Healthy Control subjects (HC). Enterobacteriaceae species were almost the highest in the fecal samples of patients. Bifidobacterium species decreased in the fecal samples of Patients compared to HC subjects. Increasing evidence indicates that changes in the microbiota composition known as Dysbiosis, can affect human health and disease. Altering the balance of the gut microbiota can also affect kidney physiology and pathology, such as IgAN. we hypothesize that the aberrantly IgA1 that produced in IgAN in response to a mucosal infection may be influenced by the composition of the patient microbiome by inducing excessive abnormal mucosal IgA responses. Study aim is to explore if IgAN patients have different microbiome composition compared with the healthy control individuals. Method Stool sample from 26 IgAN patients & from 26 healthy control individuals subjected to microbiome array and to taxonomic analysis, to characterize their microbiome compositions. Serum Creatinine\ albumin and urine proteinuria levels are used for evaluate the renal function of each IgAN patient. The clinical and laboratory evaluations will be crossed with the taxonomic data using statistical analysis methods. Results Based on our preliminary result with 11 IgAN patients and 11 healthy control individuals, there are significant differences in the microbiome composition between the two groups. IgAN patients have a significant increase in the Bacteroides phylum accompanied with a significant decrease in the amount of both the Actinobacteria and Verrucomicrobia phyla, compared with the healthy individuals. At the genus level, there is a significant increase in the Prevotella bacteria in the IgAN subjects compared with the healthy individuals. Conclusion 1. A strong association between specific bacteria population and IgAN disease, we isolate specific population of bacteria that leads to IgAN or even aggravate its manifestation. 2. It may help to predict the tendency of each individual to develop IgAN and even predict the prognosis of each IgAN patient according to their microbiome. 3. it is rational to alter the intestinal barrier, the content of gut microbiota and its metabolites in the realm of CKD using different strategies such Prebiotics and symbiosis. 4. To develop disease-specific therapies based on microbiome modulations and manipulations such as modifying the gut microbiota through diet, antibiotic therapies, probiotic, bariatric surgery, fecal transplants.