Seating System Research Articles

Semiactive Car-Seat System for Rear-End Collisions

This study proposes and simulates a smart system that can be used in production car seats to decrease whiplash risk in rear-end crashes. A sliding seat incorporating a semiactively controlled magnetorheological (MR) damper model positioned under the seat-pan is simulated with a validated biofidelic human body model. Since this is the first study that demonstrates a computer controlled anti-whiplash car seat system to the best of the authors’ knowledge, a benchmark analysis is carried out to compare the proposed semiactive seat with a state-of-the-art passive anti-whiplash car seat using 23 different crash pulses, including the moderate and high severity crash pulses within the European New Car Assessment Program (EuroNCAP) whiplash risk assessment framework. The proposed semiactive design outperforms the passive seat design by further reducing the values of the critical EuroNCAP whiplash criteria, such as NIC and Nkm, together with the loads acting on the upper neck. The semiactive seat lowers the upper-neck shear force by an amount of 4 kg and 7 kg while lessening the NIC by 10% and 21% and Nkm by 9% and 56% for the EuroNCAP crash pulses, having a delta-V of 16 km/h and 24 km/h, respectively. The findings presented in this paper can aid in the design of car seats to further mitigate whiplash risk in rear-end crashes.

Study of the Vibration Isolation Properties of a Pneumatic Suspension System for the Seat of a Working Machine with Adjustable Stiffness

This paper presents a study of the vibration isolation properties of pneumatic suspension systems for work machinery seats, with a particular focus on adjustable stiffness. It highlights the contribution that semi-active seat suspension systems make to vibration reduction, ultimately leading to improved passenger comfort levels and increased safety for vehicle users. The primary objectives of the research were twofold: firstly, to identify the key parameters of the apneumatic vibration isolation system; and secondly, to evaluate its performance in improving vibration damping. This entailed the development of a mathematical model that would foreground the movement through simulations based on different initial pressures, thus enabling the accurate prediction of real-life scenarios concerning the vibration-damping characteristics of the seating system, taking into account the different design options available for working machine technology applied at the test bed level, of which the pneumatic isolator is an integral component. In the cognitive process, the verification and validation of the formulated theoretical model play an important role. This approach enables the behaviour of the actual system to be inferred from the results of simulation studies, thus allowing the design of an appropriate vibration control system. By simulating different air bellow pressures, the characteristics of the seat suspension system can be assessed. This study provides valuable insights into optimising the vibration-damping capability of the air suspension system.

A technological solution to child safety seat errors: Efficacy of the cellular car seat

Objective Although child safety seats are highly effective in preventing injuries, they are frequently misused. Experts have identified two leading “critical misuses”: (1) loose harness straps and (2) loose vehicle attachment at the base. We designed an innovative child safety seat system that educates, instructs, and alarms participants of safety seat errors. The system includes both the Cellular Car Seat (CCS) smartphone app and a network of car seat sensors. Our objective was to determine if CCS system users had fewer child safety seat misuses than users with a child safety seat manual alone. Methods During the study visit, 92 participants completed three safety seat scenarios using a mock vehicle setup, test doll, and a convertible child safety seat: A) fully install a convertible safety seat, B) recognizing/correcting loose harness straps in a seat with intentionally loose straps, and C) recognizing/correcting loose attachment to the vehicle seat at the base in a seat with intentionally loose attachment. Intervention participants (n = 46) were asked to use the CCS app during each scenario and control participants (n = 46) were given only the paper child safety seat manual. For each scenario, researchers determined errors/misuses present at the end of the scenario, time to complete scenario, and tension achieved on the harness straps (collected via load cell). Results Compared with controls, intervention participants had significantly fewer errors and higher average harness tensions for all three scenarios; furthermore, a greater portion achieved a harness tension of 4 newtons. During Scenario A, the rate of loose harness strap errors was more than three times higher for controls and loose base attachment errors almost six times higher. We observed similar trends in Scenario B, with harness strap errors more than double for controls. In Scenario C, the rates of both critical misuse errors were four times higher for controls compared to the intervention group. Conclusions The innovative CCS system was highly effective at reducing child safety seat use errors, especially critical misuses. Reducing critical misuses will decrease injuries and fatalities among crash-involved children. The CCS system can alert families to everyday harnessing and installation errors and provide families and caregivers with ongoing, accessible support.

Impact of Wheelchair Seating Systems on Scoliosis Progression for Children With Neurologic and Neuromuscular Disorders: A Retrospective Study of Custom-Contoured Wheelchair Seating and Modular Wheelchair Seating

ObjectivesTo retrospectively evaluate the comparative effect of 2 wheelchair seating systems, Custom-Contoured Wheelchair Seating (CCS) and Modular Wheelchair Seating (MWS), on scoliosis progression in children with neuromuscular and neurologic disorders and to determine any predictors for scoliosis progression. DesignLongitudinal, retrospective cohort study. SettingA national health service regional posture and mobility service. ParticipantsNonambulant pediatric wheelchair users with neuromuscular and neurologic disorders (N=75; 36 men, 39 women; mean age at seating intervention, 10.50±3.97y) issued CCS and MWS by the South Wales Posture and Mobility Service from 2012-2022. InterventionsTwo specialized wheelchair seating systems, CCS and MWS. Main Outcome MeasuresA generalized least squares model was used to estimate the effect of seat type on Cobb angle over time. ResultsOf the 75 participants enrolled, 51% had cerebral palsy. Fifty were issued CCS and 25 were issued MWS. Baseline Cobb angle was 32.9±18.9° for the MWS group and 48.0±31.0° for the CCS group. The generalized least squares model demonstrated that time since seating intervention (χ2=122, P<.0001), seating type (χ2=52.5, P<.0001), and baseline scoliosis severity (χ2=41.6, P<.0001) were predictive of scoliosis progression. Condition was not a strong predictor (χ2=9.96, P =.0069), and sex (χ2=5.67, P=.13) and age at intervention (χ2=4.47, P=.35) were not predictive. Estimated contrasts of medical condition with seat type over time demonstrated smaller differences between MWS and CCS over time. Predicted scoliosis velocity was found to attenuate with use of CCS over time compared with MWS, although scoliosis deteriorated regardless of intervention. ConclusionsOur findings showed pediatric wheelchair users with neurologic and neuromuscular disorders prescribed CCS showed greater mitigation of scoliosis progression over time compared with those issued MWS.

Sitting Postural Management to Prevent Migration Percentage Progression in Non-Ambulatory Children with Cerebral Palsy: Randomized Controlled Trial Preliminary Data.

spastic or dyskinetic cerebral palsy, Gross Motor Function Classification System level IV-V, age 1-6 years, migration percentage <41%, and informed consent. contractures affecting the hip, anterior luxation, previous hip surgery, and lumbar scoliosis. The treatment group sat with their hips significantly abducted to reduce the head into the acetabulum in a customized system for at least five hours/day for two years. Controls sat with the pelvis and lower limbs aligned but the hips less abducted in an adaptive seating system. The primary outcome was migration percentage (MP) progression. Health-related quality of life and family satisfaction were among the secondary outcomes. The study was approved by the local ethics board and conducted in accordance with CONSORT reporting guidelines. gov ID: NCT04603625. Overall median MP progression was 1.6 after the first year and 2.5 after the second year. No significant differences were observed between the groups. MP exceeded 40% and 50% in 1.8% and 0% of the experimental group and 5.4% and 3.6% of controls in years 1 and 2, respectively. Both groups expressed satisfaction with the postural system and stable health-related quality of life. Conclusions: MP remained stable over the two-year period in both groups. Considering outliers which progressed over 50%, a more protective trend of the hip-centering sitting approach emerged, but this needs to be confirmed in a final, larger dataset.

Multi-dimensional vibration isolating properties of a 3-RPS parallel damping seat

This paper proposes a new control scheme that is composed by the sliding mode control(SMC) with three-dimensional ceiling control to reduce the multi-dimensional vibration of the vehicle’s seat. The seat suspension system is made of a kind of 3-RPS parallel mechanism, in which each limb is mainly composed by the spherical pair, spring, piston rod, damping fluid and rotary pair. Based on the single-open-chain theory, Position and Orientation Characteristics (POC) set of a 3-RPS seat mechanism was analyzed to verify its movement law. Three-dimensional seat system mathematical model was established, and the SMC and ceiling control were combined to obtain the required force. The ceiling control belongs to an ideal control method, it could provide the reference for the SMC. The comparisons between the SMC and passive seat suspension system were done when the vehicles were walking or working on E, F and G-roads. The results show that the transient amplitudes of seat acceleration outputs were reduced with the proposed control scheme. The research in this work can be extended and applied for other vehicles and improve their performance.

Therapists and patients perceptions of a mixed reality system designed to improve trunk control and upper extremity function

A prototype system aimed at improving arm function and trunk control after stroke has been developed that combines mixed-reality (MR) feedback with a mobile seat system (Holoreach). The purpose of this study was to assess the usability of Holoreach in a rehabilitation setting from both the patient and therapist perspective. Ten therapists (eight physiotherapists and two occupational therapists) used the device in their regular therapy programs for fifteen stroke patients with trunk control issues. Each patient received four individual therapy sessions with the device performed under the supervision of the therapist. Therapists and patients kept therapy diaries and used customized questionnaires. At the end of the study two focus groups were conducted to further assess usability. Generally, the prototype system is suitable for training trunk and arm control. The therapists expressed overall positive views on the impact of Holoreach. They characterized it as new, motivating, fresh, joyful, interesting, and exciting. All therapists and 80% of the patients agreed with the statement that training with Holoreach is beneficial for rehabilitation. Nonetheless, improvements are required in the hardware and software, and design. The prototype system contributes at various levels to the rapidly evolving advances in neurorehabilitation, particularly regarding the practical aspect of exercise delivery.

A Study of Seating Suspension System Vibration Isolation Using a Hybrid Method of an Artificial Neural Network and Response Surface Modelling

A reliable prediction model can greatly contribute to the research of car seating system vibration control. The novelty of this paper lies in the development of a hybrid method of an artificial neural network (ANN) and response surface methodology (RSM) to predict the peak seat-to-head transmissibility ratio of a seating suspension system and to evaluate its ride comfort for different seat design parameters. Additionally, this method can remove the experimental design of the RSM model. In this paper, four seat design parameters are selected as input parameters and arranged using the central composite design method. The peak transmissibility ratio from seat to head at 4 Hz is chosen as the response target output value. To illustrate this hybrid method, the response target output value of the peak transmissibility ratio is calculated from the frequency response of a five-degrees-of-freedom (5-DOF) lumped-parameter biodynamic seating suspension model. The input design parameters and the response target output values are used to train an ANN to establish the relationship between the seat design parameters and the peak transmissibility ratio. At the same time, the input design parameters and the response target output values predicted by the ANN are used to develop the relationship between the seat design parameters and the peak transmissibility ratio using the response surface method and linear regression models. The hybrid of the ANN and response surface methods makes the planning or design of experiments not essential. The hybrid model of the ANN and response surface method is more accurate and convenient than a linear regression model for the study of seating system vibration isolation.

A Global Assessment of Gender Quota Facilitating Mechanisms: Placement Mandates, Sanctions, and Financial Incentives

How do facilitating mechanisms affect the share of women in parliament? Specifically, is there an ideal combination of quota types and facilitating mechanisms that leads to greater female representation in parliament? This research uses a comprehensive dataset covering 186 countries in 2021 to provide a global landscape of the gender quota types and their facilitating mechanisms. Employing the OLS regression, we identified positive associations between placement mandates and strong sanctions and women’s parliamentary presence in legislative candidate system. In contrast, financial incentives under the reserved seat system showed a negative association. Our country-level analysis reveals that female aspirants face multifaceted challenges, suggesting that multiple issues should be addressed for financial incentives to effectively improve female representation.

CFD analysis on the aerodynamic coefficients of an ejection seat system at supersonic speed

In the present study, a 3-D study of the aerodynamic coefficients of an ejection seat system is performed. The analysis is performed using the Reynolds Averaged Navier-Stokes equations where an unstructured grid of the polyhedral cells is used. The aerodynamic coefficients are calculated using a density-based solver and the standard k-ε turbulence model. The investigation is performed at Mach number (Ma) = 1.25 by varying the angle of attack (α) from -15° to 15° with the increment of 5° where the yaw angle (β) is fixed at 0°. According to the findings, the magnitude of the axial force coefficient (CX) increases as α decreases whereas the value of the normal force coefficient (CZ) decreases with the increase of α. Similarly, the value of the pitching moment coefficient (Cm) decreases with the increase of α.

Research on design evaluation of wooden outdoor seating system

[Objective] Although there are many kinds of materials for outdoor seating, there are also limitations. People prefer natural wood materials which are warm in winter and cool in summer. From the perspective of sustainable development, wood substitute for natural preservative wood is replaceable, so it has become the main material for outdoor seating. The purpose of this paper is to verify the advantages of wood and wood -like materials in the application of outdoor seating with expert evaluation methods. [Methods] The Del phi expert evaluation method was used to optimize the different schemes of wood and non -wood materials in the empirical study. Based on the three levels of “environment - space - people ”, the evaluation was carried out from multiple perspectives, from the urban ecological environment appeals of the top system of the macro root layer to the extension system of the meso-generative layer of the harmonious space and place system, as well as the micro-representational layer ontology system problems involving the form, function and material technology of outdoor seating. [Result] Finally, based on the quantitative data analysis of Delphi expert evaluation method and standard deviation comparison analysis results, the outdoor seating system design of wood and imitation wood materials was obtained by experts’ preference and affirmation. [Conclusion] T he material selection of outdoor seating can be mainly wood, and the acceptance of imitation wood outdoor seating is similar to wood. When selecting outdoor seating materials, we can gradually introduce composite anticorrosive wood materials to replace non -renewable natural anticorrosive wood.

Dynamic Characteristics and Optimization of Segmented Fork Arm Seat System

To improve the low-frequency vibration isolation performance and driving comfort of the engineering seat system, a segmented fork arm seat system is proposed. Firstly, the equivalent model of the n-level segmented seat system is established, the amplitude-frequency response function and phase-frequency response function of the segmented seat system are solved and analyzed. The theoretical study shows that, with the increase of segment levels, the response time of the seat system is shortened, and the attenuation rate of response amplitude is accelerated; with the increase of segment levels, the resonance peak value of the seat system tends to shift continuously, and the low-frequency vibration isolation range expands. Secondly, according to the actual application condition of a loader, the engineering structure of the 3-level segmented fork arm seat system was built, and the structure-stiffness parameters of the segmented fork arm seat system were optimized by multi-objective genetic algorithm. The optimization results show that the 3-level segmented fork arm seat system has obvious vibration reduction effect on the sensitive frequency band of the human body. The vibration reduction effect on road excitation increases by 63.2% on average under driving conditions, 75.8% on uneven road surface, and 65.2% under operating conditions, and the subjective comfort evaluation index of human body increases by two levels.

Analysis on smart seats intelligently correcting users' sitting posture

In contemporary times, an increasing number of individuals are encountering health-related issues stemming from extended periods of sitting, primarily attributable to improper sitting posture. Hence, the introduction of an intelligent seating solution into the market is imperative and holds significant potential for commercial success. Concerns regarding the health of children, namely their spinal development, as well as the need for sedentary workers to maintain a healthy sitting posture, have become significant issues for consumers. Currently, there are certain items in the market, such as backrests, which aim to partially correct sitting posture. However, these products have limitations in terms of requiring attachment or wearing, as well as lacking sufficient data support. Consequently, the user experience and scalability of these products are considerably inadequate. Based on the analysis of consumer big data by China Business News data (CBNData), there has been a notable surge in the markets appetite for premium corrective goods in recent years. There exists a market demand for products that are closely associated, specifically smart seats. Currently, researchers have conducted investigations on the recognition and reminder systems pertaining to sitting posture. This paper aims to conduct a comprehensive analysis and evaluation of the fundamental prerequisites and advancements in intelligent seating systems by employing literature analysis and review methods.

Development of a Restraint System for Rear-Facing Car Seats

In self-driving vehicles, passengers can set their seats in an unconventional seating position, such as rear-facing. Sitting in such an orientation can increase the risk of whiplash in the head-and-neck system in a frontal impact, as frontal crashes usually have higher severities compared with rear-end crashes. This paper shows that a forward-facing front seat optimised for rear-impact protection needs to be redesigned to be used as a rear-facing seat. In the second and main part of this paper, a restraint system for rear-facing car seats is developed, and frontal impact simulations with 64 km/h of delta-V are used to evaluate its performance. The designed seating system comprises two rigid torso plates, a fixed recliner and an energy absorber under the seat pan. Without using the developed restraint system, the 50th percentile male human model is exposed to neck shear forces exceeding 600 N. With the developed restraint system, neck shear forces are less than 350 N in frontal impacts with 64 km/h of delta-V. Apart from whiplash, the risk of head, chest, lower extremity and lower back injuries are also evaluated. The results confirm that the developed restraint system successfully protects the occupant since all assessment criteria values are lower than the injury assessment reference values.

Dynamic Characteristic Analysis of a Half-Vehicle Seat System Integrated with Nonlinear Energy Sink Inerters (NESIs)

To enhance the dynamic performance of half-vehicle seat systems and reduce vibrations in both the vertical and pitching directions, a nonlinear energy sink inerter (NESI) can be introduced and aligned with lightweight design principles. A dynamic model of a half-vehicle seat system integrated with NESIs is constructed using Newton’s second law. The dynamic response of the system under pavement harmonic and random excitations is obtained using the pseudo-arc-length and harmonic balance methods and the numerical method, respectively. The dynamic behavior of the system is assessed using eight evaluation indexes. The optimal structural parameters of the NESIs are determined through the genetic algorithm. The results indicate that using NESIs attenuates resonance peaks and reduces root mean square (RMS) values for vehicle seat suspension strokes, front and rear suspension system strokes, and front and rear dynamic tire loads. However, the resonance peaks and RMS values for other performance indexes, which are vehicle seat vertical acceleration, the bodywork vertical, and pitching accelerations, exhibit an increase. When the structural parameters of the NESIs are optimized and contrasted with the original NESIs, the RMS values of the bodywork’s vertical and pitching acceleration, seat vertical acceleration, and seat suspension stroke will decrease by 23.97%, 27.48%, 23.59%, and 14.29%, respectively, and the other evaluation indexes will satisfy the limit conditions.

IoT-Enabled Adaptive Seating System for Monitoring Vital Signs and Detecting Diabetes in Individuals with Disabilities

The IoT based smart chair for measuring vital parameters and detecting types of diabetes is an innovative solution to monitor the health status of individuals with diabetes. The chair is fitted with detectors to gauge vital signs like blood sugar, levels of oxygen, and your heart rate. Additionally, the chair is capable of detecting the type of diabetes that an individual has by analysing their glucose evels We implemented a prototype of Smart IoT chair combining six custom sensors a PIC, and a chair. In this system RF communication is used for when Person is used the smart chair. If one-time rea the RFID tag then the check the body conditions using health parameters. These collected sensors data fed to microcontroller and can be displayed on LCD display. If any sensor is abnormal means, alarm goes on using buzzer. Then sensors data are updated to IoT using cloud. Acetone sensor is used to sense the exhale air problem of diabetics and update IoT. Finally, UV lamp will be ON for remove the viruses. The smart chair can also be used in hospitals and clinics to monitor patients with diabetes and provide early intervention if necessary. The chair is created to be cosy and simple to operate, with a straightforward layout allowing people to quickly access their important data. In general, the Internet of Things (I smart chair for identifying different types of metabolic disease as recording important indicators has the ability to revolutionise diabetes care by real-time monitoring and feedback to individuals and healthcare professionals.

Analysis of the aerodynamic characteristics of an ejection seat system using computational fluid dynamics

In the present work, an investigation of the aerodynamic characteristics of an ejection seat occupant is carried out using the commercially available computational fluid dynamics software ANSYS Fluent. 3D Reynolds-averaged Navier–Stokes equations are solved to obtain the aerodynamic coefficients of the ejection seat system. For this analysis, an unstructured grid is generated for the ejection seat occupant using ANSYS meshing. Validation is carried out and the performance of three different turbulence models is analyzed at Mach 0.6. Based on the most suitable turbulence model, further analysis of the aerodynamic coefficients of the ejection seat occupant is calculated at Mach numbers of 0.35, 0.45, 0.55, 0.65, and 0.75. For all values of Mach, the angle of attack is varied from −15° to 15° in 5° increments and the yaw angle is varied from 0° to 60° in 10° increments. Based on the results, it is observed that the magnitude of the axial force decreases with increasing angle of attack and yaw angle. Similarly, the normal force coefficient and pitching moment coefficient decrease with increasing angle of attack. Finally, the side force coefficient, yawing moment, and rolling moment coefficients increase with increasing yaw angle.

Ride comfort analysis of vehicle seat suspension systems: A co-simulation study

In this study, the vehicle seat suspension system installed with a semi-active magnetorheological (MR) damper is excited by the power spectral density (PSD) and its vibration control performance is evaluated using finite element analysis (FEA). The control system receives the velocity of the sprung and unsprung mass from the seat mounting locations and calculates the desired controllable damping forces available from MR damper. The effectiveness of the control systems is demonstrated by adopting ride quality evaluation method. To predict a better ride comfort and ride quality, co-simulation methodology is utilized considering the dynamic behavior of the real-world seat system. In this case, the multi-body dynamics and control system are coupled by solving the mechanical equations and the control logic. Then, the computed damping force is exchanged between the dynamics and controller in an iterative manner by passing state variables. The simulation results achieved from co-simulation methodology associated with the controller are analyzed by comparing with ISO 2631-1. The co-simulation results studied using vibration dose value (VDV), crest factor (CF) and seat effective amplitude transmissibility (SEAT) in terms of percentage improvement were found to be 44.33%, 26.66% and 17.65% respectively which were better than that for the passive suspension for a random rough road profile. Modified skyhook controller delivers superior performance for vibration suppression of the vehicle seat suspension as compared to other control policies. The application of co-simulation methodology can reduce time and cost for the development of a semi-active seat suspension system.

A nonlinear biodynamic model of seated human body exposed to vertical vibration with sensitivity analysis

The nonlinearity observed in the apparent mass of a seated human body exposed to vertical vibration demonstrates a decrease in resonance frequency as the vibration magnitude increases. However, there is a dearth of appropriate models that accurately capture this nonlinear biodynamic response. Furthermore, the impact of different properties of human body parts on this nonlinearity remains unexplored. This paper presents a model that effectively characterizes the nonlinearity in the apparent mass of a seated human body subjected to vertical vibration.The proposed model incorporates the legs, thighs, pelvis, torso, head, and viscera as key components. Nonlinear springs are employed to simulate the dynamic interactions between the human body and the seat, as well as the connection between the viscera and the pelvis/torso. To validate the model, vertical in-line and fore-and-aft cross-axis apparent masses were measured at the seat pan for 11 subjects without backrest contact, using three different vibration magnitudes (0.4, 0.6, and 1.0 m/s2 r.m.s.).A comprehensive global sensitivity analysis was conducted with the calibrated model to identify the factors that have the greatest influence on the biodynamic response. The results revealed that the stiffness of the soft tissues beneath the thighs, the mass of the thighs, and the mass of the torso were the three most influential parameters affecting the apparent mass. When considering the degree of nonlinearity in the apparent mass, the stiffness of the soft tissues beneath the thighs and the mass of the torso contributed the most.The proposed model holds significant potential for studying the nonlinear biodynamic responses of vehicle drivers and passengers. It provides a valuable tool for gaining insights into the intricate dynamics of human body vibration and can contribute to the development of improved seating systems and enhanced ride comfort in vehicles.

Identification of wheelchair seating criteria in adults with neuromuscular diseases: A Delphi study.

Adults with neuromuscular diseases like spinal muscular atrophy or Duchenne muscular dystrophy require full-time use of a wheelchair (WC) and perform all activities of daily living in a sitting position. Optimal configuration of the WC and seating system is essential to maintain the health and quality of life of users. However, few recommendations for configuration exist. The aim of this study was to identify and select 10 WC seating criteria that ensure an optimal sitting posture for health and quality of life. A four round Delphi method was used to collect the opinions of WC users and health professionals (HP), separately. First, the HP were asked if they believed that different criteria would apply to each disease. Then the HP and SMA II and DMD WC user experts responded to electronic surveys in 4 rounds. Overall, 74 experts took part: 31 HP, 21 WC users with SMA II and 22 WC users with DMD. In total, 52% of HP believed that different criteria would apply to each disease. Ten criteria were identified by the HP for SMA II and 10 for DMD. Of the 40 criteria selected, 30 (75%) were common to each panel. Six topics were similar across panels: comfort, access to the joystick, prevention of pain, stability, pressure management and power seat functions. However, power seat functions did not reach consensus between HP and WC users (30-33% of agreement for HP and 93-100% for the WC user panels, p < 0.001). Adults with SMA II and DMD had similar WC seating needs. Therefore, the same recommendations can be applied to these groups. Further research is necessary to understand the impact of cost on the prescription of power seat functions by health professionals.