Biomedical subjects

Rosemarie Cooper

Publications and source records attributed to Rosemarie Cooper.

At least 19 recordsLinked to original sources

PubMed2006

Development and qualitative assessment of the GAME(Cycle) exercise system.

Increased physical activity is important for reducing the risk of cardiovascular disease. However, among people with disabilities, inactivity is prevalent. In order to encourage exercise among members of this group, an exercise system combining arm ergometry with video gaming, called the GAME(Cycle) was previously developed. User input was received through an arm crank ergometer on a swivel, with the angular velocity of the ergometer resistance wheel controlling one axis and rotation of ergometer about the swivel controlling the other. The purpose of this study was to detail the algorithms used in this device and present novel features included in a second generation of the GAME(Cycle). The features include a wheel on base, a steering return mechanism, and wireless fire buttons. A focus group of clinicians (n = 8), wheelchair users (n = 8), and clinician wheelchair users (n = 2) was conducted to evaluate the features of the GAME(Cycle). The focus group suggested improvements to the steering mechanism and to reduce vibration in the system. However, the focus group enjoyed the GAME(Cycle) and felt that it would encourage exercise among persons with disabilities.

Algorithms↗

PubMed2006

Engineering better wheelchairs to enhance community participation.

With about 2.2 million Americans currently using wheeled mobility devices, wheelchairs are frequently provided to people with impaired mobility to provide accessibility to the community. Individuals with spinal cord injuries, arthritis, balance disorders, and other conditions or diseases are typical users of wheelchairs. However, secondary injuries and wheelchair-related accidents are risks introduced by wheelchairs. Research is underway to advance wheelchair design to prevent or accommodate secondary injuries related to propulsion and transfer biomechanics, while improving safe, functional performance and accessibility to the community. This paper summarizes research and development underway aimed at enhancing safety and optimizing wheelchair design.

Activities of Daily Living↗

PubMed2005

Vibration exposure of individuals using wheelchairs over sidewalk surfaces.

According to the International Standards Organization 2631-1 standard on human vibration, individuals in a seated position are at risk of injury due to whole-body vibrations when exposed for long periods of time. Wheelchair users fit this description perfectly; however, little research has been conducted to evaluate the amount of vibration transmitted to a wheelchair user. The vibration exposure produced by traversing nine surfaces was evaluated by having 10 individuals without disabilities propel over them in both a manual wheelchair at 1 m/s and a powered wheelchair at 1 and 2 m/s. Root-mean squared (RMS) vertical vibration was examined to determine if differences existed between surfaces. At 1 m/s for both the manual and the powered wheelchair the 8-mm bevel interlocking concrete surface produced significantly higher RMS vertical vibration than the other surfaces. At 2 m/s in the powered wheelchair, the poured concrete surface (control) produced the significantly highest RMS vertical vibration. Based on the manual and power wheelchair results of this study, use of selected ICPI pavers would be acceptable for any route traveled by individuals using wheelchair. Furthermore, a 90 degrees herringbone pattern is preferred over the 45 degrees pattern, and it is recommended that for safety reasons regarding vibration exposure a bevel of less than 6 mm should be used.

Adult↗

PubMed2005

Fatigue testing of selected suspension manual wheelchairs using ANSI/RESNA standards.

OBJECTIVES: To evaluate the durability and value of 3 common suspension manual wheelchairs and to compare the results with those of previously tested lightweight and ultra-lightweight folding-frame wheelchairs. DESIGN: Standardized fatigue testing and cost analysis of 3 suspension manual wheelchairs from 3 different manufacturers. SETTING: A rehabilitation engineering center. SPECIMENS: Nine suspension manual wheelchairs. INTERVENTIONS: Wheelchairs were fitted with a standardized wheelchair test dummy and tested on a series of fatigue tests, consistent with those developed by the International Organization for Standardization. Main outcome measures Fatigue life (measured as the number of equivalent cycles completed) and value (equivalent cycles divided by cost) were compared among all wheelchairs. RESULTS: Analysis of variance revealed significant differences (P< or =.05) in the number of equivalent cycles among the suspension wheelchairs tested. When compared with previously tested ultra-lightweight and lightweight wheelchairs, the suspension wheelchairs failed to show significant improvements; however, significant improvements were found between individual suspension and lightweight wheelchairs. CONCLUSIONS: We found little evidence to suggest that suspension manual wheelchairs provide advantages in terms of durability or value over standard lightweight and ultra-lightweight folding-frame wheelchairs.

Equipment Design↗

PubMed2005

Effect of a pushrim-activated power-assist wheelchair on the functional capabilities of persons with tetraplegia.

OBJECTIVES: To test the differences between a pushrim-activated power-assisted wheelchair (PAPAW) and a traditional manual wheelchair while performing common driving activities and to assess their relative merits for people with tetraplegia. DESIGN: Repeated measures. SETTING: An activities of daily living (ADL) laboratory within a rehabilitation research center. PARTICIPANTS: Fifteen full-time manual wheelchair users with tetraplegia due to a spinal cord injury. INTERVENTIONS: Participants propelled both their own manual wheelchairs and a PAPAW 3 times over an ADL course. The order in which the 2 different wheelchairs were presented to the participants was randomized. MAIN OUTCOME MEASURES: Each participant's heart rate was monitored throughout testing by a digital, wireless heart-rate monitor. Time to complete the course was recorded, and participants were surveyed with a visual analog scale after the first, third, fourth, and sixth trials to determine the ease of completing each obstacle and their ergonomic preferences between the 2 wheelchairs. Participants also were observed throughout the trials to determine how much assistance they needed to complete each obstacle course. RESULTS: After using a Bonferroni adjustment, 4 obstacles (carpet, dimple strips, up a ramp, up a curb cut) were rated as being significantly easier ( P <.001) to complete when using the PAPAW. Participants also showed a significant decrease in mean heart rate throughout all 3 trials ( P =.015, P =.001, P =.003, respectively) when using a PAPAW. The amount of assistance needed by participants, the responses to ergonomic questions, and the overall time to complete the ADL course did not differ significantly between the 2 wheelchairs. CONCLUSIONS: For subjects with tetraplegia, PAPAWs have the potential to improve functional capabilities during certain ADLs, especially when propelling up ramps, over uneven surfaces, and over thick carpet.

Activities of Daily Living↗

PubMed2005

Evaluation of the safety and durability of low-cost nonprogrammable electric powered wheelchairs.

OBJECTIVE: To evaluate whether a selection of low-cost, nonprogrammable electric-powered wheelchairs (EPWs) meets the American National Standards Institute (ANSI)/Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) Wheelchair Standards requirements. DESIGN: Objective comparison tests of various aspects of power wheelchair design and performance of 4 EPW types. SPECIMENS: Three of each of the following EPWs: Pride Mobility Jet 10 (Pride), Invacare Pronto M50 (Invacare), Electric Mobility Rascal 250PC (Electric Mobility), and the Golden Technologies Alanté GP-201-F (Golden). SETTING: Rehabilitation engineering research center. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Static tipping angle; dynamic tipping score; braking distance; energy consumption; climatic conditioning; power and control systems integrity and safety; and static, impact, and fatigue life (equivalent cycles). RESULTS: Static tipping angle and dynamic tipping score were significantly different across manufacturers for each tipping direction (range, 6.6 degrees-35.6 degrees). Braking distances were significantly different across manufacturers (range, 7.4-117.3 cm). Significant differences among groups were found with analysis of variance (ANOVA). Energy consumption results show that all EPWs can travel over 17 km before the battery is expected to be exhausted under idealized conditions (range, 18.2-32.0 km). Significant differences among groups were found with ANOVA. All EPWs passed the climatic conditioning tests. Several adverse responses were found during the power and control systems testing, including motors smoking during the stalling condition (Electric Mobility), charger safety issues (Electric Mobility, Invacare), and controller failures (Golden). All EPWs passed static and impact testing; 9 of 12 failed fatigue testing (3 Invacare, 3 Golden, 1 Electric Mobility, 2 Pride). Equivalent cycles did not differ statistically across manufacturers (range, 9759-824,628 cycles). CONCLUSIONS: Large variability in the results, especially with respect to static tipping, power and control system failures, and fatigue life suggest design improvements must be made to make these low-cost, nonprogrammable EPWs safe and reliable for the consumer. Based on our results, these EPWs do not, in general, meet the ANSI/RESNA Wheelchair Standards requirements.

Equipment Design↗

PubMed2005

Virtual reality and computer-enhanced training applied to wheeled mobility: an overview of work in Pittsburgh.

Some aspects of assistive technology can be enhanced by the application of virtual reality. Although virtual simulation offers a range of new possibilities, learning to navigate in a virtual environment is not equivalent to learning to navigate in the real world. Therefore, virtual reality simulation is advocated as a useful preparation for assessment and training within the physical environment. We are engaged in several efforts to develop virtual environments and devices for mobility skills assessment and training, exercise training, and environment assessment. Virtual reality offers wheelchair users a training tool in different risk-free environments without any indoor (e.g., walls, furniture, and stairs) and outdoor (e.g., curb cuts, uneven terrain, and street traffic) physical constraints. Virtual reality technology will probably become more common in the field of assistive technology, especially given the rapid expansion of gaming technology and the continued exponential growth of computing power.

Computer Simulation↗

PubMed2004

Assessing the influence of wheelchair technology on perception of participation in spinal cord injury.

OBJECTIVE: To investigate factors related to the wheelchair, impairment, and environment that affect perception of participation of persons with spinal cord injury (SCI) in activities performed in 3 settings: in the home, in the community, and during transportation. DESIGN: Cross-sectional study. SETTING: Research centers and a specialized assistive technology (AT) clinic in Pittsburgh (Pitt). Research centers and community-based rehabilitation technology suppliers in Saint Louis (SL). PARTICIPANTS: Seventy wheelchair users with SCI. INTERVENTIONS: Subjects from Pitt and SL completed a written survey of AT usage in daily activities. MAIN OUTCOME MEASURES: Subjects were asked 5 questions within each setting (home, community, transportation) related to their perceived reason for functional limitations. RESULTS: The wheelchair was the most commonly cited factor limiting participation, followed by physical impairment and physical environment. Twenty-one percent of subjects with paraplegia reported pain as a limiting factor for their transportation use, significantly more (P=.047) than subjects with tetraplegia (3%). A trend (P=.099) was seen toward a higher percentage of subjects with tetraplegia (tetraplegia, 7%; paraplegia, 3%) reporting lack of equipment as a limiting factor for use of transportation. Differences were also seen across sites. CONCLUSIONS: The wheelchair was the most commonly cited limiting factor, followed by physical impairment and physical environment. The wheelchair is the most important mobility device used by persons with SCI and the one that users most associate with barriers.

Activities of Daily Living↗

PubMed2004

Impact of a pushrim-activated power-assisted wheelchair on the metabolic demands, stroke frequency, and range of motion among subjects with tetraplegia.

OBJECTIVES: To determine differences in metabolic demands, stroke frequency, and upper-extremity joint range of motion (ROM) during pushrim-activated power-assisted wheelchair (PAPAW) propulsion and traditional manual wheelchair propulsion among subjects with tetraplegia. DESIGN: Repeated measures. SETTING: A biomechanics laboratory within a Veterans Affairs medical center. PARTICIPANTS: Fifteen full-time manual wheelchair users who had sustained cervical-level spinal cord injuries. INTERVENTIONS: Participants propelled both their own manual wheelchairs and a PAPAW through 3 different resistances (slight, 10W; moderate, 12W; high, 14W) on a wheelchair dynamometer. Each propulsion trial was 3 minutes long. MAIN OUTCOME MEASURES: Primary variables that were compared between the 2 wheelchairs were participants mean steady-state oxygen consumption, ventilation, heart rate, mean stroke frequency, and maximum upper-extremity joint ROM. RESULTS: When using the PAPAW, participants showed a significant ( P <.05) decrease in mean oxygen consumption and ventilation throughout all trials. Mean heart rate was significantly lower when using the PAPAW for the high resistance trial. Stroke frequency was significantly lower when using the PAPAW for the slight and moderate resistances. Overall joint ROM was significantly lower when using the PAPAW. CONCLUSIONS: For subjects with tetraplegia, PAPAWs reduce the energy demands, stroke frequency, and overall joint ROM when compared with traditional manual wheelchair propulsion.

Adult↗

PubMed2004

The GAME(Cycle) exercise system: comparison with standard ergometry.

BACKGROUND: It is well established that physical activity is beneficial to health. For the individual in a wheelchair, a regular exercise program might not be available or may be too difficult to participate in physically and/or psychologically. Many exercise devices and regimes are boring. The goal, therefore, is to develop a device that makes exercise more exciting and, thus, motivates a person to exercise more or for a longer period of time, yielding increased energy expenditure. Our laboratory developed an interface between an arm ergometer and a computer game that allows the user to control game play on the screen as if using a joystick. The purpose of this study was to determine (a) whether the GAME(Cycle) system would elicit an exercise effect similar to arm ergometry, (b) whether perceived exertion would be different between the 2 devices, and (c) individuals' impressions regarding the GAME(Cycle) system. METHODS: Thirteen individuals who used wheelchairs participated in the study. Participants were asked to exercise for 2 separate, 19-minute sessions. For 1 session, a GAME(Cycle) system was used and for the other session, the same arm ergometer was used, but without the computer game being played. Physiologic data and perceived exertion were collected for each session. RESULTS: There were significant differences between playing the game and not playing the game for VO2 (P = 0.03) and VCO2 (P = 0.02), with higher values being found when the game was played. Perceived exertion was not significantly different between the 2 trials. CONCLUSION: GAME(Cycle) appears to be similar in nature with respect to energy expenditure to arm ergometry. Because this study was conducted on athletes, further research is needed with sedentary individuals to determine exercise effects and perceived exertion.

Adult↗

PubMed2004

Evaluation of selected sidewalk pavement surfaces for vibration experienced by users of manual and powered wheelchairs.

BACKGROUND: Obstacles such as bumps, curb descents, and uneven driving surfaces cause vibrations that affect the wheelchair, and in turn, the wheelchair user. Chronic exposure can cause low-back pain, disk degeneration, and other harmful effects. Little research has been conducted to assess the vibrations experienced by wheelchair users. OBJECTIVE: The purpose of this study was to conduct an evaluation of the vibration exposure during electric-powered wheelchair driving and mechanical energy requirements for manual wheelchair propulsion over selected sidewalk surfaces. The goal was to determine the criteria for a wheelchair-pedestrian access route that does not require excessive propulsive work or expose wheelchair users to potentially harmful vibrations. METHODS: Ten unimpaired individuals participated in this study. Six sidewalk surfaces were tested. Measured variables included power of the acceleration per octave, mechanical work to propel over surfaces, peak acceleration, and frequency at which peak acceleration occurs. RESULTS: For both the manual and electric-powered wheelchair, at 1 m/s, significant differences were found in peak accelerations between the seat and footrest (P < 0.0001) and between the sidewalk surfaces (P = 0.004). The greatest risk for injury caused by shock and vibration exposure occurs at frequencies near the natural frequency of seated humans (4-15 Hz). The values for work required to propel over the surfaces tested were not statistically significantly different. Besides appearance and construction, the only distinguishing characteristic was surface roughness caused by the joints. CONCLUSION: When treating the poured concrete sidewalk as the standard, surfaces 2, 3, 5, and 6 compared most favorably in terms of vibration exposure, whereas surface 4 produced mixed results. Surfaces 2, 3, 5, and 6 yielded results that were similar to the poured concrete sidewalk and could be considered acceptable for wheelchair users. In conclusion, surfaces other than the traditional poured concrete can be used for pedestrian access routes without adding vibration exposure or reducing propulsion efficiency.

Adult↗

PubMed2004

Push for power.

Explore the source record for details and available documents.

Electric Power Supplies↗

PubMed2004

Preliminary assessment of a prototype advanced mobility device in the work environment of veterans with spinal cord injury.

The INDEPENDENCE 3000 IBOT Transporter (IBOT) is an electronically stabilizing device for people with disabilities. The purpose of this study was to collect qualitative data on the potential for the IBOT to improve employment satisfaction of veterans who use wheelchairs to work. This study was based upon observations by trained clinicians, and responses to a survey completed by four men with traumatic spinal cord injury, who worked in an office environment. The mean age of the subjects was 52 +/- 8.8 years. The subjects used the devices to hold eye-level discussions with colleagues, climb stairs, ascend steep ramps, and negotiate curbs. When subjects were asked to rate the ease of getting around in the IBOT compared to their personal wheelchairs, they responded with a mean of 6.7 +/- 1.8 on a 10-point visual analog scale. The response to rating the overall function of the IBOT within their working environment yielded a rating of 6.0 +/- 2.8. Half of the users felt that the IBOT would help them at work and all thought it should be made available to veterans who use wheelchairs. A larger study should be conducted to determine if the IBOT affects work performance and the ability to return to work.

Employment↗

PubMed2003

Tips and falls during electric-powered wheelchair driving: effects of seatbelt use, legrests, and driving speed.

OBJECTIVE: To measure the response of a test dummy while traversing common obstacles encountered by users of electric-powered wheelchairs (EPWs) to determine whether optimal wheelchair fit, use of seatbelts, and driving speed affect the frequency and severity of EPW tips and falls. DESIGN: Repeated-measures comparison study. SETTING: Constructed environment both in and around a Veterans Affairs medical center. PARTICIPANT: A 50th percentile Hybrid II anthropometric test dummy (ATD) was used to simulate a person driving an EPW. INTERVENTIONS: The ATD was driven in 4 different EPWs over commonly encountered obstacles at speeds of 1 and 2m/s, with and without the use of a seatbelt, and at varying legrest heights. MAIN OUTCOME MEASURES: The response and motion of the ATD were observed and recorded as no fall, loss of control (the ATD falls forward or sideways but remains in the EPW), the ATD falls out of the EPW, or the EPW tips completely. RESULTS: A total of 97 adverse events out of 1700 trials were recorded: 88 were losses of control (instability) and 9 were ATD falls. No complete tips of any EPW occurred. Univariate statistical analysis indicated a significant relationship between the adverse events and the use of seatbelts, legrest condition, and test obstacles (P<.05). A mixed-model analysis confirmed the significant relationships between the adverse events and the use of seatbelts, legrest condition, and test obstacles (P<.05). However, the mixed model indicated that (1) there was no significant relationship between the adverse events and driving speed and (2) no one obstacle was designated to be the most problematic. CONCLUSION: Persons who use EPWs should use seatbelts and legrests while driving their EPWs, and clinicians should include common driving tasks when assessing the proper set-up of EPWs.

Acceleration↗

PubMed2003

Use of the Independence 3000 IBOT Transporter at home and in the community.

BACKGROUND: The INDEPENDENCE 3000 IBOT Transporter (IBOT) is an electronically stabilizing mobility device for people with disabilities. It operates in 4 functions: Standard, Balance (raised on 2 rear wheels), 4 Wheel (for inclines, curbs, and uneven terrain), and Remote (for loading into a vehicle). OBJECTIVE: The purpose of this study was to observe the IBOT at use in the home and in the community. METHODS: Data were obtained via observations by trained clinicians, data recorded from a computerized data logger, and reports from each expert. PARTICIPANTS: Participants included 10 unimpaired nonwheelchair users (6 men, 4 women) and 4 expert wheelchair users (men with spinal cord injuries, T7-L1). The participants used the IBOT to perform a variety of activities, including holding eye-level discussions with colleagues and shopping by balancing on 2 wheels, going up and down steep ramps, traversing outdoor surfaces (eg, grass, dirt trails), and climbing curbs. OBSERVATIONS: The Balance and 4-Wheel functions were helpful and worked well. The IBOT required attention to control in the Standard function. The seat height was too high for most tables and desks, and the IBOT was challenging to use in the bathroom. CONCLUSION: The IBOT is a functional mobility device that expands the options of wheelchair users. It is most useful outdoors and where there is sufficient space to use its unique Balance function.

Activities of Daily Living↗

PubMed2003

Investigating neck pain in wheelchair users.

OBJECTIVE: Despite the fact that wheelchair users are exposed to risk factors for neck and upper back pain (NP), little is known about the impact and possible diagnoses associated with NP. The purpose of this study was to examine the significance of NP in wheelchair users and to determine if a portion of the NP may be myofascial in origin. DESIGN: Cross-sectional cohort study using questionnaires and physical exams to evaluate NP in a convenience sample of wheelchair users from the National Veteran's Wheelchair Games. Main outcome measures included reported NP, visual analog scale of neck complaints, Neck Disability Index, and physical examination findings of trigger points. RESULTS: Sixty-six percent of subjects reported NP since becoming a wheelchair user and, 60% reported pain during the past month. Neither age nor length of time in a wheelchair was significantly different between those subjects who did and those subjects who did not report pain. Of those respondents who reported NP, 60% visited the doctor about the pain and 40% limited their daily activities due to the pain. Trigger-point palpation reproduced pain in 54% of those respondents who experienced pain in the past month (n = 34). CONCLUSION: This study provides a first step in defining the prevalence and significance of NP among wheelchair users. Clinicians who work with this population need to ask subjects about symptoms and consider a myofascial origin for that pain when considering treatment.

Adult↗

PubMed2002

Driving characteristics of electric-powered wheelchair users: how far, fast, and often do people drive?

OBJECTIVES: To determine the driving characteristics of electric-powered wheelchair users during unrestricted community activities and to compare the activity levels among an active group and a group of regular users. DESIGN: Multisite engineering evaluation of electric-powered wheelchair driving activity during unrestricted community mobility. SETTING: Data were collected in the communities of Pittsburgh, PA, and the National Veterans Wheelchair Games (NVWG) in San Antonio, TX. PARTICIPANTS: Seventeen people participated, all of whom used electric-powered wheelchairs as their primary means of mobility. INTERVENTION: Each subject was asked standarized questions about self and wheelchair use. Data logger and sensor installed on wheelchair. Data downloaded from logger. MAIN OUTCOME MEASURES: Speed, distance traveled, and the time that each subject's personal wheelchair was being driven were recorded for 24hr/d over approximately 5 days for each subject by using a custom-built data logger. RESULTS: The NVWG group traveled faster than the Pittsburgh group, but this difference was only statistically significant on the first day. The NVWG group was more likely to travel longer than the Pittsburgh group with significant differences seen in day 4 (P = .03) and day 5 (P = .05). Total distance traveled during the 5-day period and average distance traveled per day were also significantly different between the groups (P = .02 for both 5-day distance and daily distance), with the NVWG group traveling longer (17,164 +/- 8708m) when compared with the Pittsburgh group (8335 +/- 7074m) over the 5-day period. Both distance traveled and speed increased during afternoon and evening hours. The maximum distance traveled by any subject for each hour across the 2 groups was used to create the theoretic maximum distance day, which resulted in 7970m of driving. CONCLUSION: Drivers of electric-powered wheelchairs are most active during the afternoon and evening hours. Over the 5-day period of this study, there was little variation in the speed or distance driven per day. The subjects participating in the NVWG were more active than their counterparts during a typical week at home. The maximum theoretic distance that a wheelchair user in our group would travel is less than 8km. The range of current electric-powered wheelchairs appears adequate, if not generous, for the subjects in our study.

Activities of Daily Living↗

PubMedDate not supplied

Issues in maintenance and repairs of wheelchairs: A pilot study.

In this pilot study, we assessed wheelchair durability and its effect on user satisfaction. Specifically, we examined the characteristics of the participants' wheelchairs, the types of maintenance and repairs completed, and whether the participants' satisfaction was affected by problems with their wheelchairs. A convenience sample of 130 participants who used wheelchairs as their primary means of mobility was recruited. Participants completed a questionnaire about their wheelchairs, the maintenance and repair history, and their satisfaction levels. Results showed that 26% of the participants had completed a wheelchair repair in the past 6 months, 16% had completed general maintenance, and 27% had completed tire repairs. Neither hours of wheelchair use nor wheelchair age affected repair or maintenance frequency. Participants were generally satisfied with their wheelchairs. Better understanding of wheelchair maintenance and repair issues will guide improvements in wheelchair design and enhance the community participation of individuals who use wheelchairs.

Adult↗