Hyogo Institute of Assistive Technology

Japan

Hyogo Institute of Assistive Technology

Japan
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Hashizume T.,Toyo University | Kitagawa H.,Hyogo Institute of Assistive Technology | Lee H.,Shibaura Institute of Technology | Ueda H.,Morinomiya University of Medical Sciences | And 2 more authors.
Studies in Health Technology and Informatics | Year: 2015

A vertical slope of sidewalks significantly inhibits to the mobility of manual wheelchair users in their daily life. International guidelines of the vertical slope are specified approximately 4% or 5% (1:20) gradient or less as preferred, and allow 8.3% (1:12) as its maximum when it is impossible. Relevant research of the physical strain for wheelchair users with pushing on slopes, and the validity assessment of slope guidelines have been investigated. However, the analysis for the effect of a slope distance and their transient performance are still remained. The purpose of this study is to clarify the physiological and biomechanical characteristics of manual wheelchair users that propelling a wheelchair on an uphill slope. We measured these data by a metabolic analysis system, a heart rate monitor system and an instrumented wheelchair wheel. Sixteen unimpaired subjects (non-wheelchair users) were examined to investigate the effect of a long slope with 120m distance and 8% gradient. And five wheelchair users with cervical cord injury were examined to evaluate the influence of different gradients (5%, 6.7%, 8.3%, 10% and 12.5%) with 3m length in laboratory. Our experimental results of the long slope showed that wheelchair propulsion velocity and power increased considerably at the beginning of the slope where the peak mean value of them were 0.96 m/s and 70.8W and they decreased linearly to 0.55m/s and 33.6W at final interval. A mean oxygen uptake and heart rate were increased as the distance increased and their results indicated the extremely high exercise intensity at a final interval that were 1.2liter /min and 152bpm. While wheelchair pushing cadence reduced after an initial interval, mean of strokes per10m increased to compensate the decrease of upper limb's power. The results of different gradients indicated that the normalized power of subjects with cervical cord injury was significant difference between each subject in the ability to climb a slope. Mean normalized power were 0.23W/kg on a 5% slope, 0.24W/kg on 6.7%, and 0.26W/kg on 8.3% respectively. Based on these findings, we examined the relationship between the theoretical normalized power and the lowest velocity to climb a slope, and we might indicate the ability to push on an uphill slope for the persons with manual wheelchair user. © 2015 The authors and IOS Press. All rights reserved.


Booka M.,Hiroshima International University | Yoneda I.,Nishikyushu University | Hashizume T.,Toyo University | Lee H.,Hyogo Institute of Assistive Technology | And 2 more authors.
Studies in Health Technology and Informatics | Year: 2015

It is often experienced that low tire pressure of the wheelchair not only increases running resistance, but also reduces parking brake performance. In this study, the required driving forces for different tire pressures were experimentally measured and evaluated. It was indicated from the result that the wheelchair with proper tire pressure could be run with less workload of wheelchair-user. Then it was also indicated that the wheelchair with a lower tire pressure needed more workload of wheelchair-user even on hard level surface. © 2015 The authors and IOS Press. All rights reserved.


Hashizume T.,Hyogo Institute of Assistive Technology | Kitagawa H.,Hyogo Institute of Assistive Technology | Mohri T.,Tokushima University | Ueda H.,Morinomiya University of Medical Sciences | And 3 more authors.
Assistive Technology Research Series | Year: 2011

Objective. The vertical slope in sidewalk is a big barrier for the wheelchair users. In Japan, the Law for Promoting Barrier-free Transport and Facilities for the Elderly and the Disabled and it's guideline indicate that the vertical slope in sidewalk is expected to be 5% gradient or less and it can be allowed 8% or less when it is unavoidable. Grounds of this guideline depended from existing studies and related documents reported that most of wheelchair users were able to climb up 5% gradient slope and 24/25 subjects were able to climb up 8% slope. However, the research on the relationship between the feature of slope with gradient, distance, ascending speed and the physical load of wheelchair users was still remained. The purpose of this study is to evaluate the physical load of the wheelchair users by the oxygen uptake values and the wheelchair driving force while they are propelling a wheelchair upward on a slope, and to realize barrier-free environment. Methods. The dynamic wheelchair driving force was measured by using a torque meter equipped on a wheelchair to analyze the required force when ascending on a slope. The oxygen uptake values and heart rate were measured with the portable metabolic analysis system and the heart rate monitor system. Unimpaired adult subjects were asked to propel the wheelchair on the slope that was used for the emergency escape route of the handicapped person's sports facilities. The profile of the slope was 8% gradient, 120m distance, and 7.6m height. The strokes and speed to propel the wheelchair was set to be free of each subject. Results and Conclusion. The Oxygen Cost Index of the wheelchair users while propelling manual wheelchair upward on the slope indicated approximately 0.017 (liter/one meter) and it was about three times higher than that of by flat floor in the room (0.006 l/meter). The averaged heart rate value at the summit of the slope showed an increase of 150bpm, and was equivalent to the Borg Scale 15 (hard). It was corresponding to the feeling of physical load (it was a very hard, limit) with all subjects. The averaged wheelchair driving power while ascending the slope presented approximately 58W, and it was needed by about four times as large as flat floor (15W). We conclude that 8% gradient and 120m distance of the slope cause extremely high physical load for the wheelchair users even in the case of unimpaired persons. So, we should pay attention to the slope gradient of guideline, and should improve the slope of sidewalk to reduce the physical load of wheelchair users. The Oxygen Cost Index and the power of wheelchair driving force are useful index for the assessment of barrier-free road environment, route selection with lower stress, and the universal design of slope. © 2011 The authors and IOS Press. All rights reserved.


Ikeda H.,Kyoto Institute of Technology | Kitagawa H.,Hyogo Institute of Assistive Technology | Mihoshi A.,Kinki University
Assistive Technology Research Series | Year: 2011

Objective For the wheelchair user, door to door vehicles are a necessary method of transportation. However, when wheelchair users drive a vehicle, they have to make use of driving support equipment, and they must adapt themselves to the vehicle. It has been clarified that when wheelchair users drive they have difficulty maintaining body position in the situation of receiving the effects of centrifugal force, such as on curves. This paper is concerned with this driving situation and the development of "body support equipment" for wheelchair drivers which can keep body posture and not effect the driving operation in such a situation. Main Content To understand the driving load for wheelchair drivers, the situation of driving on curves, which is the most stressful condition, was examined. Evaluation methods for both the driver and the vehicle were used to clarify the questionnaire, muscle activity, three-dimensional motion, steering-wheel angle, and acceleration-velocity. Results On the left curve, the seating posture is easily changed because of the operation style. Therefore, body support by the seat became lower, so muscle load on the left curve was basically higher. Also, the main opinion of the drivers was a difficulty to keep body posture, so the left curve has a lower evaluation than the right curve. On the right curve, the operation style keeps body posture strongly through centrifugal force. However, around the end of the curve, the balance between centrifugal force and keeping posture is broken, and turning back the steering becomes later than on the left curve. Therefore, at the end of the curve, the vehicle swerves strongly and the muscle load of the right shoulder is greater. It is possible to keep the body posture securely on the right curve and the driving is easier. However, the vehicle is less stable than the left curve. Conclusion Several organizations have been approached for both long-term and short-term counter measures. Short-term measures are proposed for the vehicle interior using driving support equipment that can ensure a stable sitting posture. The design proposed in this paper has the advantages of low cost and easy replacement to another vehicle. © 2011 The authors and IOS Press. All rights reserved.


Kobayashi T.,Orthocare Innovations | Leung A.,Hong Kong Polytechnic University | Akazawa Y.,Hyogo Institute of Assistive Technology | Hutchins S.,University of Salford
Topics in Stroke Rehabilitation | Year: 2012

Background: Ankle-foot orthoses (AFOs) have been reported to have positive effects on the temporal-spatial parameters and kinematics and kinetics of gait in patients with stroke. The center of mass (COM) may be used to represent whole body movement and energy cost in gait, and therefore COM movement would also be positively influenced with use of an appropriate AFO. Objective: To investigate the effect of AFOs on the sagittal plane displacement of the COM in patients with stroke hemiplegia. Methods: Five male subjects with stroke hemiplegia participated in this pilot study. The trajectory of the COM in the sagittal plane, gait speed, bilateral step length, step width, and bilateral stance time were analyzed while participants ambulated under 2 test conditions: with an AFO or with footwear only. The height of the 2 peaks of the vertical displacement of the COM in a gait cycle was subsequently measured and normalized to body height. Statistical analyses were conducted using a nonparametric Friedman test. Results: Gait speed, bilateral step length, and the normalized peak height of the vertical COM trajectory during stance phase on the affected leg all revealed statistically significant increases (P <.05), and step width showed significant decreases (P <.05) under the AFO condition when compared to the footwear-only condition. Conclusions: An AFO may influence the vertical displacement of the COM in patients with stroke hemiplegia. The results of this pilot study therefore suggested that vertical movement of COM could potentially serve as a useful parameter to evaluate the effect of an AFO. © 2012 Thomas Land Publishers, Inc.


Kobayashi T.,Orthocare Innovations | Leung A.K.L.,Hong Kong Polytechnic University | Akazawa Y.,Hyogo Institute of Assistive Technology | Hutchins S.W.,University of Salford
Disability and Rehabilitation: Assistive Technology | Year: 2016

Purpose: The Berg balance scale (BBS) is commonly used to assess balancing ability in patients with stroke. The BBS may be a good candidate for clinical assessment prior to orthotic intervention, if it correlates well with outcome measures such as gait speed. The purpose of this study was to investigate the correlation between the BBS measured prior to walking with an ankle-foot orthosis (AFO) and specific temporal-spatial parameters of gait when walking with an AFO donned. Methods: Eight individuals with chronic stroke participated in this study. Balancing ability was assessed using the BBS, while temporal-spatial parameters of gait (gait speed, bilateral step length, stride length and step width) were measured using a three-dimensional motion analysis system. The correlations between the BBS and gait parameters were investigated using a non-parametric Kendalls Tau (τ) correlation analysis. Results: The BBS showed correlations with gait speed (τ = 0.64, p < 0.05), the step length of the affected side (τ = 0.74, p < 0.05), and the stride length (τ = 0.64, p < 0.05). Conclusions: Assessment of the BBS prior to AFO prescription may potentially help clinicians to estimate the gait speed achievable following orthotic intervention in patients with stroke.Implications for RehabilitationAssessment of the BBS prior to AFO prescription may help orthotists to estimate the gait speed following an orthotic intervention in patients with stroke.Assessment of the BBS prior to AFO prescription may help orthotists to understand overall balance and postural control abilities in patients with stroke.A larger scale multifactorial analysis is warranted to confirm the results of this pilot study. © 2014 Informa UK Ltd.


Kitayama I.,Kinki University | Omori K.,Hyogo Institute of Assistive Technology | Sugimoto Y.,Hyogo Institute of Assistive Technology
Assistive Technology Research Series | Year: 2011

Objective. The objective of this research was to determine the spotlight brightness and width specifications needed for a flashlight used by individuals with visual impairment. Main Content. First, a flashlight with a light-emitting diode (LED) light source was built to have adjustable spotlight brightness and width. An aspheric lens was fitted over the LED in order to achieve uniform brightness. The spotlight brightness could be adjusted by changing the current supplied to the LED, and the spotlight width could be adjusted by changing the distance between the LED and the lens. Second, the effects of brightness and width were investigated in an object-search experiment where 27 participants with visual impairment attempted to locate target objects by using the developed flashlight under dimmed lights. The time needed to locate the designated objects was measured, and the ease of finding the objects was evaluated. There were 3 settings each for spotlight brightness and width, making a total of 9 setting conditions. The participants performed 4 object searches per condition, making a total of 36 trials per subject. If the time exceeded 35 s, the object was regarded as unfound and the trial was rated as a failure. There were 2 target objects: a Braille block (tactile ground surface indicator) and a beverage can. In one trial, the participant searched for either of the two target objects. Each target object was placed randomly at 1 of 4 points, which were located 1 m or 3 m from the participant at 15° to the left or right. Results. From the experimental results, the failure rate (number of failures/number of trials) and other indicators were examined to assess how easily objects were found with the aid of the flashlight. At each spotlight setting, 108 trials were conducted, and the failure rate at each setting was as follows: at the smallest spotlight width (200 mm), the failure rates were 0.167 at the highest brightness (2000 lx), 0.185 at medium brightness (1200 lx) and 0.231 at the lowest brightness (600 lx); at a spotlight width of 300 mm, the failure rates were 0.102 at 1200 lx, 0.167 at 600 lx and 0.231 at 400 lx; at a spotlight width of 400 mm, the failure rates were 0.157 at 600 lx, 0.176 at 400 lx and 0.194 at 200 lx. Conclusion. These results show that a spotlight of 300 mm width and 1200 lx brightness had the lowest failure rate. At each fixed illuminance, the failure rate increased as spotlight diameter was decreased; at each fixed diameter, the failure rate increased as illuminance was decreased. © 2011 The authors and IOS Press. All rights reserved.


Kobayashi T.,Hong Kong Polytechnic University | Leung A.K.L.,Hong Kong Polytechnic University | Akazawa Y.,Hyogo Institute of Assistive Technology | Hutchins S.W.,University of Salford
Brain Injury | Year: 2011

Primary objective: To investigate the methodology using a manual ankle joint resistive torque measurement device to evaluate the contribution of the neural component of ankle joint resistive torque in patients with stroke. Research design: Within-subject comparison to compare the ankle joint resistive torque between fast and slow stretching conditions. Methods and procedures: Ten patients with stroke participated in this study. The incremental ratio of ankle joint resistive torque at the ankle angular position of 5° dorsiflexion under the fast stretching condition in comparison to the slow one was calculated in each patient. Main outcomes and results: A significant increase (p<0.01) in the ankle joint resistive torque was demonstrated under the fast stretching condition in comparison to the slow one in all patients and the mean ankle joint resistive torque was 4.6 (SD=1.7) Nm under the slow stretching condition, while it was 8.4 (SD=4.1) Nm under the fast stretching condition at the ankle angular position of 5° dorsiflexion. The incremental ratio ranged from 9.4-139.3% among the patients. Conclusions: The results of this study demonstrated the potential advantage of the device to evaluate the contribution of the neural component of ankle joint resistive torque. © 2011 Informa UK Ltd. All rights reserved.


Kobayashi T.,Hong Kong Polytechnic University | Leung A.K.L.,Hong Kong Polytechnic University | Akazawa Y.,Hyogo Institute of Assistive Technology | Naito H.,Osaka University | And 2 more authors.
Prosthetics and Orthotics International | Year: 2010

The purpose of this study was to design a new automated stiffness measurement device which could perform a simultaneous measurement of both dorsi-and plantarflexion angles and the corresponding resistive torque around the rotational centre of an articulated ankle-foot orthosis (AAFO). This was achieved by controlling angular velocities and range of motion in the sagittal plane. The device consisted of a hydraulic servo fatigue testing machine, a torque meter, a potentiometer, a rotary plate and an upright supporter to enable an AAFO to be attached to the device via a surrogate shank. The accuracy of the device in reproducing the range of motion and angular velocity was within 4 and 1 respectively in the range of motion of 30° (15° plantarflexion to 15° dorsiflexion) at the angular velocity of 10°/s, while that in the measurement of AAFO torque was within 8 at the 0° position. The device should prove useful to assist an orthotist or a manufacturer to quantify the stiffness of an AAFO and inform its clinical use. © 2010 ISPO.


Omori K.,Hyogo Institute of Assistive Technology | Yanagihara T.,Kinki University | Kitagawa H.,Hyogo Institute of Assistive Technology | Ikeda N.,KICTEC Inc.
Studies in Health Technology and Informatics | Year: 2015

Some people with low vision or elderly persons tend to walk while watching a nearby floor, therefore, they often overlook or hard to read suspended signs. In this study, we propose two kinds of voice guides, and an experiment is conducted by participants with low vision using these voice guides and graphic floor signs in order to investigate effectiveness of these combinations. In clock position method (CP), each direction of near facilities are described in using an analogy of a 12-hour clock. Meanwhile, in numbering method (NU), near facilities are put the number in clockwise order, however, each direction are only illustrated in a crossing sign. As a result of an experiment, it is showed that both voice guides are effective for pedestrians with low vision. NU is used as a complement of graphic floor signs. Meanwhile, CP is used independently with graphic floor signs, however, there is a risk in the case of using in the environment where pedestrians are easy to mistake the reference direction defined by the sounding speaker. © 2015 The authors and IOS Press. All rights reserved.

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