Probability of independent walking and wheeled mobility in individuals with cerebral palsy.

AIM: To estimate the probability of independent walking and wheeled mobility in individuals with cerebral palsy (CP) at home and in the community in relation to age and gross motor function. METHOD: This was a longitudinal cohort study using data reported into the combined Swedish CP follow-up programme and national quality registry from October 2000 to October 2022. Walking, walking with aids, wheeled mobility, and assisted mobility defined independent or assisted mobility at home and in the community, based on the Functional Mobility Scale with additional data on wheelchair performance, were assessed. RESULTS: There were 52 858 examinations reported for 6647 individuals with CP (age range 0-32 years, follow-up period 0-22 years). Most children and adults in Gross Motor Function Classification System (GMFCS) levels I or II walked without assistive devices. The probability of dependence on others for mobility in the community was high for both children and adults in GMFCS levels III to V. INTERPRETATION: Although independent mobility is vital for participation and social inclusion, many children and adults with CP are dependent on others for mobility. We recommend clinicians, together with families and individuals with CP, explore how to increase access to independent mobility from an early age and continuously throughout the life course. WHAT THIS PAPER ADDS: • There is a high probability of independent walking in Gross Motor Function Classification System (GMFCS) levels I to II. • Mobility options vary most at home and in the community in GMFCS level III. • Being dependent on others for mobility is likely in GMFCS levels III to V.

Understanding Wheelchair Use in Older Adults From the National Health and Aging Trends Study.

OBJECTIVE: To identify the trends of wheelchair use and physical characteristics among older people who used wheelchairs relative to those who did not. DESIGN: Cohort and survey. SETTING: General community. PARTICIPANTS: 7026 participants (N=7026) were selected from the 2011 cohort of the National Health and Aging Trends Study (NHATS), which is made up of Medicare beneficiaries over the age of 65. Repeated observations among participants in the 2011 cohort were analyzed in the 4 following rounds: 2013 (N=4454), 2015 (N=3327), 2017 (N=2623), and 2019 (N=2091). Participants were divided into 2 groups: those who used and did not use wheelchairs. INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Physical characteristics, including pain, strength limitation, balance problems, mobility disability, as well as the frequency of going outside. RESULTS: The number of older adults who use wheelchairs had increased significantly from 4.7 per 100 people in 2011 to 7.1 in 2019 (P<.001). The logistic regression analysis indicated that participants who reported less frequently going out were at least 4.27 times more likely to be wheelchair users than non-wheelchair users (P<.01). Participants who reported health and physical problems were at least 2.48 times more likely to be wheelchair users than non-wheelchair users from 2011 to 2017 (P<.0001). Balance or coordination problems increased (24%-38%) significantly among non-wheelchair users from 2011 to 2019 (all P<.05). CONCLUSIONS: Current wheelchair users reported more physical difficulties and were much less likely to go outside. This lower outdoor mobility could be due to physical difficulties or potential barriers in physical and socio-cultural environments. In addition, older adults who do not use wheelchairs showed increasing physical problems over time (including balance or coordination problems). Clinicians should consider older wheelchair users' health and physical limitations when prescribing wheelchairs.

Accessible Autonomous Transportation and Services: Design Considerations From the Perspective of Consumers and Providers.

OBJECTIVE: To understand the priorities and preferences of people with disabilities (PwDs) and older adults regarding accessible autonomous vehicles (AVs) to address existing transportation barriers. DESIGN: Two national surveys, Voice of the Consumer and Voice of the Provider, were conducted to gather feedback from accessible AV consumers and providers, respectively, in the United States. SETTING: This U.S.-based study focused on PwDs and older adults who may face transportation challenges and those who provide or design AV solutions. PARTICIPANTS: The 922 consumers and 45 providers in the surveys encompassed a diverse range of disability types, caregiver roles, and age groups (N = 967). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The main outcomes were consumer usage needs and provider preferences for features in accessible autonomous transportation. Patterns in usage needs and feature preferences through 2-step clustering algorithm were applied subsequent to the descriptive analysis of participant demographics and their responses. RESULTS: Participants strongly preferred AV features enhancing personal transportation, especially for rural medical appointments. Most sought comprehensive AV automated features. Wheelchair users emphasized accessible entrances, particularly for lower-income brackets ($25,000-$49,000). Provider priorities closely aligned with consumer preferences, reinforcing content validity. CONCLUSIONS: The study highlights the importance of prioritizing wheelchair accessibility in AVs and improving access to medical appointments, especially in rural and low-income communities. Implications include developing inclusive AV services for PwDs and underserved populations. The research establishes a foundation for a more equitable and accessible transportation landscape through AV technology integration.

Socio-ecological Barriers to Leisure Time Physical Activity in Spanish Wheelchair Users With Spinal Cord Injury: Associations With Sociodemographic Characteristics and Functional Independence.

OBJECTIVE: (1) To assess prevalence and severity of socio-ecological barriers to leisure time physical activity (LTPA) in a sample of adults with spinal cord injury (SCI); (2) to examine the association of these barriers with sociodemographic characteristics and functional independence (FI); and (3) to explore which socio-ecological levels of barriers might be associated with LTPA. DESIGN: Cross-sectional study. SETTING: Neurorehabilitation Hospital specialized in SCI. PARTICIPANTS: 207 wheelchair users with SCI living in the community who attended a comprehensive check-up (22.7% women, 47.5±10.7 mean age; N=207). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The short version of the Barriers to Physical Activity Questionnaire for People with Mobility Impairments was used to measure socio-ecological barriers to LTPA. The Spinal Cord Independence Measure III was used to measure FI. The Physical Activity Recall Assessment for People with SCI was used to quantify LTPA. Several multiple linear regression models were computed to examine the associations between socio-ecological barriers and sociodemographic factors, LTPA and FI. RESULTS: A high prevalence of barriers to LTPA was found. Seven of these barriers (2 intrapersonal, 3 organizational, and 2 community) were present for >60% of the participants. Intrapersonal and organizational barriers had a higher effect on participants with lower FI and women. Interpersonal barriers were higher for older participants and with lower FI, while community barriers were higher for unemployed participants. Finally, intrapersonal and interpersonal barriers were negatively associated with LTPA, and FI revealed as a moderator of the intrapersonal barriers-LTPA relation. CONCLUSIONS: Given their high prevalence and their association with LTPA, the development of interventions targeting socio-ecological barriers to LTPA in people with SCI becomes crucial. The associations of these barriers with FI and sociodemographic characteristics should also be considered for these interventions to be as specific and effective as possible.

Differences in Glenohumeral Joint Contact Forces Between Recovery Hand Patterns During Wheelchair Propulsion With and Without Shoulder Muscle Weakness: A Simulation Study.

The majority of manual wheelchair users (MWCU) develop shoulder pain or injuries, which is often caused by impingement. Because propulsion mechanics are influenced by the recovery hand pattern used, the pattern may affect shoulder loading and susceptibility to injury. Shoulder muscle weakness is also correlated with shoulder pain, but how shoulder loading changes with specific muscle group weakness is unknown. Musculoskeletal modeling and simulation were used to compare glenohumeral joint contact forces (GJCFs) across hand patterns and determine how GJCFs vary when primary shoulder muscle groups are weakened. Experimental data were analyzed to classify individuals into four hand pattern groups. A representative musculoskeletal model was then developed for each group and simulations generated to portray baseline strength and six muscle weakness conditions. Three-dimensional GJCF peaks and impulses were compared across hand patterns and muscle weakness conditions. The semicircular pattern consistently had lower shear (anterior-posterior and superior-inferior) GJCFs compared to other patterns. The double-loop pattern had the highest superior GJCFs, while the single-loop pattern had the highest anterior and posterior GJCFs. These results suggest that using the semicircular pattern may be less susceptible to shoulder injuries such as subacromial impingement. Weakening the internal rotators and external rotators resulted in the greatest increases in shear GJCFs and decreases in compressive GJCF, likely due to decreased force from rotator cuff muscles. These findings suggest that strengthening specific muscle groups, especially the rotator cuff, is critical for decreasing the risk of shoulder overuse injuries.

A semi-structured interview to capture manual wheelchair use for mobility activities among individuals with spinal cord injury in real-life situations: development and content validity of the Wheelchair Mobility Activity Log (WC-MAL).

STUDY DESIGN: Mixed-method approach. OBJECTIVES: To develop and assess the content validity of a semi-structured interview that captures the lived experience of using a manual wheelchair among individuals with SCI in the real world, the Wheelchair Mobility Activity Log (WC-MAL). SETTING: SCIR-Group (UDESC)/Brazil. METHODS: Developing the WC-MAL comprised five steps: (1) defining the construct-based on the International Classification of Functioning, Disability and Health (ICF); (2) identifying relevant activities from other assessment instruments and interviews with the end-users (14 Individuals with SCI and 13 rehabilitation professionals); (3) Selecting the items - activities were linked to ICF codes and grouped into sets; (4) developing the scoring scales based on interviews with the end-users; and, (5) evaluating content validity in accordance with the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). The content validity ratio (CVR) for each item and scale and the overall instrument content validity index (CVI) were calculated. RESULTS: From an initial draft of 295 activities identified, a set of 222 activities was linked to the ICF domain of "Mobility (d4)" and further refined to generate the 23 items in the WC-MAL. Three scales were developed to assess Frequency (how often), Performance (how well), and Assistance (assistance needed) levels. The items and scales showed a CVR superior to the critical value established (≥0.64). The general CVI value was 0.96. CONCLUSION: The WC-MAL is a promising clinical instrument with adequate content validity to assess the spontaneous use of the manual wheelchair in the real world among individuals with SCI.

Satisfaction with social roles and activities across mobility status among persons with spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To examine the differences in satisfaction with social roles and activities among ambulatory individuals, manual wheelchair users, and power wheelchair users with spinal cord injuries (SCIs). SETTING: Community setting. METHODS: Participants completed surveys of their demographics and clinical data as well as the Spinal Cord Injury - Quality of Life Satisfaction with Social Roles and Activities- Short Form. Participants' mobility status was categorized into (1) ambulatory individuals, (2) independent manual wheelchair users, and (3) power wheelchair/scooter users. One-way ANOVA and ANCOVA were used, respectively, to examine unadjusted and adjusted differences in satisfaction with social roles and activities across mobility status. Adjustment covariates included age, sex, time since SCI, and SCI injury level. RESULTS: A total of 129 participants (mean age = 47.4 ± 13.6 years, 73% male) were included in the analyses. Unadjusted (F = 3.8, p = 0.03) and adjusted models (F = 3.4, p = 0.04) evidenced significant differences in satisfaction with social roles and activities according to mobility status. Pairwise Bonferroni Post-Hoc analysis indicated that manual wheelchair users were more satisfied with their social roles and activities when compared to ambulatory individuals (mean difference = 2.8, p < 0.05). CONCLUSIONS: Due to the current challenges associated with walking recovery after SCIs, clinicians may want to discuss the use of wheelchairs with individuals with limited walking ability when the goal is to improve participation and quality of life. Emphasizing alternative means of mobility may enhance satisfaction with social roles and activities.

Preliminary field validity of ActiGraph-based energy expenditure estimation in wheelchair users with spinal cord injury.

STUDY DESIGN: Cross-sectional validation study. OBJECTIVES: To develop a raw acceleration signal-based random forest (RF) model for predicting total energy expenditure (TEE) in manual wheelchair users (MWUs) and evaluate the preliminary field validity of this new model, along with four existing models published in prior literature, using the Doubly Labeled Water (DLW) method. SETTING: General community and research institution in Pittsburgh, USA. METHODS: A total of 78 participants' data from two previous studies were used to develop the new RF model. A seven-day cross-sectional study was conducted to collect participants' free-living physical activity and TEE data, resting metabolic rate, demographics, and anthropometrics. Ten MWUs with spinal cord injury (SCI) completed the study, with seven participants having valid data for evaluating the preliminary field validity of the five models. RESULTS: The RF model achieved a mean absolute error (MAE) of 0.59 ± 0.60 kcal/min and a mean absolute percentage error (MAPE) of 23.6% ± 24.3% on the validation set. For preliminary field validation, the five assessed models yielded MAE from 136 kcal/day to 1141 kcal/day and MAPE from 6.1% to 50.2%. The model developed by Nightingale et al. in 2015 achieved the best performance (MAE: 136 ± 96 kcal/day, MAPE: 6.1% ± 4.7%), while the RF model achieved comparable performance (MAE: 167 ± 99 kcal/day, MAPE: 7.4% ± 5.1%). CONCLUSIONS: Two existing models and our newly developed RF model showed good preliminary field validity for assessing TEE in MWUs with SCI and the potential to detect lifestyle change in this population. Future large-scale field validation studies and model iteration are recommended.

Obesity in wheelchair users with long-standing spinal cord injury: prevalence and associations with time since injury and physical activity.

STUDY DESIGN: Secondary analysis of cross-sectional data from the ALLRISC cohort study. OBJECTIVES: To investigate the prevalence of obesity and its association with time since injury (TSI) and physical activity (PA) in wheelchair users with long-standing (TSI > 10 years) spinal cord injury (SCI). SETTING: Community, The Netherlands. METHODS: Wheelchair users with SCI (N = 282) in TSI strata (10-19, 20-29, and ≥30 years) and divided in meeting SCI-specific exercise guidelines or not. Waist circumference (WC) and body mass index (BMI) were assessed. Participants were classified as being obese (WC > 102 cm for men, WC > 88 cm for women; BMI ≥ 25 kg/m2) or not. Logistic regression analyses were performed to investigate the associations between obesity and TSI and PA. RESULTS: Almost half of the participants (45-47%) were classified as obese. TSI was significantly associated with obesity, the odds of being obese were 1.4 higher when having a 10 years longer TSI. Furthermore, the odds of being obese were 2.0 lower for participants who were meeting the exercise guidelines. CONCLUSIONS: The prevalence of obesity is high in people with long-standing SCI. Those with a longer TSI and individuals who do not meet the exercise guidelines are more likely to be obese and need to be targeted for weight management interventions.

Safety and feasibility of in-hospital autonomous transportation using a driverless mobility for patients with musculoskeletal disorders: preliminary clinical study to achieve mobility as a service in medical care.

BACKGROUND: Recent advancements in and the proliferation of autonomous mobility technology, such as intelligent wheelchairs, have made it possible to provide mobility services for patients with reduced mobility due to musculoskeletal disorders. In the present study, we conducted a preliminary clinical study to assess the safety and feasibility of in-hospital autonomous transportation using a driverless mobility (wheelchair) for patients with musculoskeletal disorders. METHODS: From January to February 2022, 51 patients with musculoskeletal disorders exhibiting gait disturbance who presented to our institution were included in the present study. Driverless mobility rides were conducted over a straight-line distance of 100 m from the orthopaedic outpatient reception to the payment counter after the outpatient consultation. We assessed the quality of life using an EQ-5D-5 L index and pain using a VAS score before riding the mobility to investigate the patient's condition. After the ride, a questionnaire survey was conducted to assess patient satisfaction on a 5-point scale. In addition, adverse events during the mobility ride were investigated. RESULTS: Overall satisfaction levels showed that 44 out of 51 (86%) patients rated the level as 3 or higher. There were no significant differences in the level of satisfaction based on the cause of disorders or EQ-5D-5 L Index. Among 19 patients who rated the level of satisfaction as 2-3, the ratio of postoperative patients and those with pain tended to be higher (p < 0.05). While 26 of 51 (51%) patients reported moments of feeling unsafe during the mobility ride, no actual adverse events, such as collisions, were observed. CONCLUSIONS: An in-hospital autonomous transportation service using a driverless mobility for patients with musculoskeletal disorders demonstrated high satisfaction levels and was safe with no severe adverse events observed. The expansion of autonomous mobility deployment is expected to achieve mobility as a service in medical care.

Spectrum and patterns of shoulder pathology on MRI in symptomatic elite wheelchair basketball athletes.

BACKGROUND: Wheelchair basketball (WCB) is a popular para-sport adapted for athletes with physical disabilities. Shoulder injuries are commonly reported among WCB athletes. However, the understanding of the specific patterns and characteristics of shoulder injuries in WCB players is currently limited, and there is a lack of comprehensive literature available on this subject. OBJECTIVES: To investigate the spectrum of pathologies observed in elite wheelchair basketball (WCB) athletes referred for MRI evaluation of symptomatic injuries of the shoulder. METHODS: Retrospective review of consecutive elite WCB athletes referred for MRI evaluation of symptomatic shoulder injury. Demographic, clinical, and functional data including international wheelchair basketball federation (IWBF) classification of each athlete were collected. A total of 28 MRI studies were reviewed. Excluding MRI examinations of the same shoulder, 18 study cases were assessed for pathology of the rotator cuff (RC), labrum, long-head of biceps tendon, glenohumeral and acromioclavicular joints, and osseous lesions of the humerus or glenoid. Correlations between clinical-demographic features and MRI findings were statistically evaluated. RESULTS: Supraspinatus tears were observed in 72.2%, infraspinatus tears in 50%, and subscapularis tears in 38.9% shoulders. Articular-sided partial tears frequently involved posterior supraspinatus (88.9%) and anterior infraspinatus (100%). Labral tears were seen in 38.9%, with involvement of the posterosuperior labrum in all tears. Hill-Sachs and osseous Bankart lesions (5.6%), and anterior-inferior labral tears (11.1%), were uncommon findings. Statistically significant correlations were observed of low IWBF point class and non-ambulatory athletes with subscapularis tendinosis (p = 0.015, p = 0.001) and tearing (p = 0.050, p = 0.013), and athletes with limited trunk control with subscapularis tendinosis (p = 0.013). CONCLUSIONS: RC tears are common in elite WCB athletes with pattern of RC and labral tearing suggesting internal (superior-posterior) impingement as a contributory pathoetiologic mechanism. Non-ambulatory, low IWBF point class athletes, as well as those with limited trunk control have a statistically significant increase in subscapularis tendon pathology on MRI.

Intelligent systems for sitting posture monitoring and anomaly detection: an overview.

The number of people who need to use wheelchair for proper mobility is increasing. The integration of technology into these devices enables the simultaneous and objective assessment of posture, while also facilitating the concurrent monitoring of the functional status of wheelchair users. In this way, both the health personnel and the user can be provided with relevant information for the recovery process. This information can be used to carry out an early adaptation of the rehabilitation of patients, thus allowing to prevent further musculoskeletal problems, as well as risk situations such as ulcers or falls. Thus, a higher quality of life is promoted in affected individuals. As a result, this paper presents an orderly and organized analysis of the existing postural diagnosis systems for detecting sitting anomalies in the literature. This analysis can be divided into two parts that compose such postural diagnosis: on the one hand, the monitoring devices necessary for the collection of postural data and, on the other hand, the techniques used for anomaly detection. These anomaly detection techniques will be explained under two different approaches: the traditional generalized approach followed to date by most works, where anomalies are treated as incorrect postures, and a new individualized approach treating anomalies as changes with respect to the normal sitting pattern. In this way, the advantages, limitations and opportunities of the different techniques are analyzed. The main contribution of this overview paper is to synthesize and organize information, identify trends, and provide a comprehensive understanding of sitting posture diagnosis systems, offering researchers an accessible resource for navigating the current state of knowledge of this particular field.

Evaluation of power wheelchair driving performance in simulator compared to driving in real-life situations: the SIMADAPT (simulator ADAPT) project-a pilot study.

OBJECTIVE: The objective of this study was to evaluate users' driving performances with a Power Wheelchair (PWC) driving simulator in comparison to the same driving task in real conditions with a standard power wheelchair. METHODS: Three driving circuits of progressive difficulty levels (C1, C2, C3) that were elaborated to assess the driving performances with PWC in indoor situations, were used in this study. These circuits have been modeled in a 3D Virtual Environment to replicate the three driving task scenarios in Virtual Reality (VR). Users were asked to complete the three circuits with respect to two testing conditions during three successive sessions, i.e. in VR and on a real circuit (R). During each session, users completed the two conditions. Driving performances were evaluated using the number of collisions and time to complete the circuit. In addition, driving ability by Wheelchair Skill Test (WST) and mental load were assessed in both conditions. Cybersickness, user satisfaction and sense of presence were measured in VR. The conditions R and VR were randomized. RESULTS: Thirty-one participants with neurological disorders and expert wheelchair drivers were included in the study. The driving performances between VR and R conditions were statistically different for the C3 circuit but were not statistically different for the two easiest circuits C1 and C2. The results of the WST was not statistically different in C1, C2 and C3. The mental load was higher in VR than in R condition. The general sense of presence was reported as acceptable (mean value of 4.6 out of 6) for all the participants, and the cybersickness was reported as acceptable (SSQ mean value of 4.25 on the three circuits in VR condition). CONCLUSION: Driving performances were statistically different in the most complicated circuit C3 with an increased number of collisions in VR, but were not statistically different for the two easiest circuits C1 and C2 in R and VR conditions. In addition, there were no significant adverse effects such as cybersickness. The results show the value of the simulator for driving training applications. Still, the mental load was higher in VR than in R condition, thus mitigating the potential for use with people with cognitive disorders. Further studies should be conducted to assess the quality of skill transfer for novice drivers from the simulator to the real world. Trial registration Ethical approval n ∘ 2019-A001306-51 from Comité de Protection des Personnes Sud Mediterranée IV. Trial registered the 19/11/2019 on ClinicalTrials.gov in ID: NCT04171973.

Towards an accurate rolling resistance: Estimating intra-cycle load distribution between front and rear wheels during wheelchair propulsion from inertial sensors.

Accurate assessment of rolling resistance is important for wheelchair propulsion analyses. However, the commonly used drag and deceleration tests are reported to underestimate rolling resistance up to 6% due to the (neglected) influence of trunk motion. The first aim of this study was to investigate the accuracy of using trunk and wheelchair kinematics to predict the intra-cyclical load distribution, more particularly front wheel loading, during hand-rim wheelchair propulsion. Secondly, the study compared the accuracy of rolling resistance determined from the predicted load distribution with the accuracy of drag test-based rolling resistance. Twenty-five able-bodied participants performed hand-rim wheelchair propulsion on a large motor-driven treadmill. During the treadmill sessions, front wheel load was assessed with load pins to determine the load distribution between the front and rear wheels. Accordingly, a machine learning model was trained to predict front wheel load from kinematic data. Based on two inertial sensors (attached to the trunk and wheelchair) and the machine learning model, front wheel load was predicted with a mean absolute error (MAE) of 3.8% (or 1.8 kg). Rolling resistance determined from the predicted load distribution (MAE: 0.9%, mean error (ME): 0.1%) was more accurate than drag test-based rolling resistance (MAE: 2.5%, ME: -1.3%).

Driving Assistance System with Obstacle Avoidance for Electric Wheelchairs.

A system has been developed to convert manual wheelchairs into electric wheelchairs, providing assistance to users through the implemented algorithm, which ensures safe driving and obstacle avoidance. While manual wheelchairs are typically controlled indoors based on user preferences, they do not guarantee safe driving in areas outside the user's field of vision. The proposed model utilizes the dynamic window approach specifically designed for wheelchair use, allowing for obstacle avoidance. This method evaluates potential movements within a defined velocity space to calculate the optimal path, providing seamless and safe driving assistance in real time. This innovative approach enhances user assistance and safety by integrating state-of-the-art algorithms developed using the dynamic window approach alongside advanced sensor technology. With the assistance of LiDAR sensors, the system perceives the wheelchair's surroundings, generating real-time speed values within the algorithm framework to ensure secure driving. The model's ability to adapt to indoor environments and its robust performance in real-world scenarios underscore its potential for widespread application. This study has undergone various tests, conclusively proving that the system aids users in avoidance obstacles and ensures safe driving. These tests demonstrate significant improvements in maneuverability and user safety, highlighting a noteworthy advancement in assistive technology for individuals with limited mobility.

Transformable Quadruped Wheelchairs Capable of Autonomous Stair Ascent and Descent.

Despite advancements in creating barrier-free environments, many buildings still have stairs, making accessibility a significant concern for wheelchair users, the majority of whom check for accessibility information before venturing out. This paper focuses on developing a transformable quadruped wheelchair to address the mobility challenges posed by stairs and steps for wheelchair users. The wheelchair, inspired by the Unitree B2 quadruped robot, combines wheels for flat surfaces and robotic legs for navigating stairs and is equipped with advanced sensors and force detectors to interact with its surroundings effectively. This research utilized reinforcement learning, specifically curriculum learning, to teach the wheelchair stair-climbing skills, with progressively increasing complexity in a simulated environment crafted in the Unity game engine. The experiments demonstrated high success rates in both stair ascent and descent, showcasing the wheelchair's potential in overcoming mobility barriers. However, the current model faces limitations in tackling various stair types, like spiral staircases, and requires further enhancements in safety and stability, particularly in the descending phase. The project illustrates a significant step towards enhancing mobility for wheelchair users, aiming to broaden their access to diverse environments. Continued improvements and testing are essential to ensure the wheelchair's adaptability and safety across different terrains and situations, underlining the ongoing commitment to technological innovation in aiding individuals with mobility impairments.

Peer-to-Peer Ultra-Wideband Localization for Hands-Free Control of a Human-Guided Smart Stroller.

We propose a hands-free control system for a human-guided smart stroller. The proposed method uses real-time peer-to-peer localization technology of the human and stroller to realize an intuitive hands-free control system based on the relative position between the human and the stroller. The control method is also based on functional and mechanical safety to ensure the safety of the stroller's occupant (child) and the pilot (parent) during locomotion. In this paper, first, we present a preliminary investigation of the humans' preference for the relative position in the context of hands-free guided strollers. Then, we present the control method and a prototype implemented with an electric wheelchair and UWB sensors for localization. We present an experimental evaluation of the proposed method with 14 persons walking with the developed prototype to investigate the usability and soundness of the proposed method compared to a remote joystick and manual operation. The evaluation experiments were conducted in an indoor environment and revealed that the proposed method matches the performance of joystick control but does not perform as well as manual operation. Notably, for female participants, the proposed method significantly surpasses joystick performance and achieves parity with manual operation, which shows its efficacy and potential for a smart stroller. Also, the results revealed that the proposed method significantly decreased the user's physical load compared to the manual operation. We present discussions on the controllability, usability, task load, and safety features of the proposed method, and conclude this work with a summary assessment.

The Push Forward in Rehabilitation: Validation of a Machine Learning Method for Detection of Wheelchair Propulsion Type.

Within rehabilitation, there is a great need for a simple method to monitor wheelchair use, especially whether it is active or passive. For this purpose, an existing measurement technique was extended with a method for detecting self- or attendant-pushed wheelchair propulsion. The aim of this study was to validate this new detection method by comparison with manual annotation of wheelchair use. Twenty-four amputation and stroke patients completed a semi-structured course of active and passive wheelchair use. Based on a machine learning approach, a method was developed that detected the type of movement. The machine learning method was trained based on the data of a single-wheel sensor as well as a setup using an additional sensor on the frame. The method showed high accuracy (F1 = 0.886, frame and wheel sensor) even if only a single wheel sensor was used (F1 = 0.827). The developed and validated measurement method is ideally suited to easily determine wheelchair use and the corresponding activity level of patients in rehabilitation.

How Integration of a Brain-Machine Interface and Obstacle Detection System Can Improve Wheelchair Control via Movement Imagery.

This study presents a human-computer interaction combined with a brain-machine interface (BMI) and obstacle detection system for remote control of a wheeled robot through movement imagery, providing a potential solution for individuals facing challenges with conventional vehicle operation. The primary focus of this work is the classification of surface EEG signals related to mental activity when envisioning movement and deep relaxation states. Additionally, this work presents a system for obstacle detection based on image processing. The implemented system constitutes a complementary part of the interface. The main contributions of this work include the proposal of a modified 10-20-electrode setup suitable for motor imagery classification, the design of two convolutional neural network (CNNs) models employed to classify signals acquired from sixteen EEG channels, and the implementation of an obstacle detection system based on computer vision integrated with a brain-machine interface. The models developed in this study achieved an accuracy of 83% in classifying EEG signals. The resulting classification outcomes were subsequently utilized to control the movement of a mobile robot. Experimental trials conducted on a designated test track demonstrated real-time control of the robot. The findings indicate the feasibility of integration of the obstacle detection system for collision avoidance with the classification of motor imagery for the purpose of brain-machine interface control of vehicles. The elaborated solution could help paralyzed patients to safely control a wheelchair through EEG and effectively prevent unintended vehicle movements.

Sitting Pressure Measurements in Wheelchair Users-Can the Effects of Daily Relief Activities Be Depicted?

Seat pressure measurements in wheelchair users have been available for some time; however, repeated measurements from a commercially available pressure mat over 90 min did not differ in the pressure-loaded measurement area or the coordinates of the center of pressure, even in participants who were able to reposition themselves in the wheelchair. The question therefore arises: to what extent are there other parameters that reflect the activity of wheelchair users with the pressure mat? To investigate this, a commercial pressure mat (BodiTrak®) was used to perform the measurements of pressure of 33 adult wheelchair-dependent people with spinal cord injury after 30 and 90 min sitting on the cushion. In addition to the standard output of the pressure mat, graph-based surface analyses (calculation of the area of maximum pressure, calculation of the pressure-loaded measurement area, and pressure-area ratio) was performed retrospectively using Python 3.7. The analysis of the measurements after 30 and 90 min was performed by distinguishing the participants between those who could actively change their position (N = 24) and those who could not (N = 9). The parameters of the pressure mat and the graph-based analyses remained unchanged for active participants. In participants who were unable to actively change their position, the area of maximum pressure and the pressure-area ratio (ratio of maximum pressure area and total pressure-loaded area) increased. Significant differences between minutes 30 and 90 are only found for the pressure-area ratio. Thus, when measuring the seat pressure of wheelchair users, the pressure-area ratio should be taken into account as it reflects the daily relief activities of wheelchair users.