Simulator for Optimal Wheelchair Design

Sasaki, Makoto; Kimura, Takeshi; Matsuo, Koichiro; Obinata, Goro; Iwami, Takehiro; Miyawaki, Kazuto; Kiguchi, Kazuo

doi:10.20965/jrm.2008.p0854

Cited by 17 publications

(10 citation statements)

References 17 publications

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“…Reportedly, as a result of the wheelchair propulsion, more than half of the long-term wheelchair users experience secondary disorders such as arthralgia, rotator cuff tear, ulnar nerve injury, and carpal tunnel syndrome [7][8][9][10]. The problem inspired many research studies essentially linked with the improvement of the mechanical efficiency of the wheelchair propulsion and reducing physical load [11][12][13][14][15].…”

Section: Open Accessmentioning

confidence: 99%

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Shoulder joint contact force during lever-propelled wheelchair propulsion

et al. 2015

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The aim of this study was to obtain quantitative results about shoulder contact force during wheelchair lever propulsion when the gear ratio of the lever propulsion mechanism is changing. The effect of the gear ratio on the shoulder contact force was investigated for few different wheelchair loading. For the experiments we designed a special mechatronic wheelchair simulator that allowed the simulation of different gear ratios of the wheelchair lever propulsion mechanism and simulation of different road inclinations. The same simulator was also used for simulation of a hand rim propelled wheelchair. We conducted also a handrim propulsion experiment and used the results from it for comparison with the lever propulsion data. Four nondisabled male adults with no prior wheeling experience participated in the experiment. In the first tests, a lever propelled wheelchair was simulated with the simulator. The target speed of the wheelchair was set to 2 km/h. For the test, the gear ratio was varied from 1.5 to 1/1.5. A load torque was applied to the rear wheels to imitate road inclinations of 0°, 2° and 4°. In the second part of the test, the simulator was structured to simulate a handrim propelled wheelchair. The participants were asked to keep the same speed (2 km/h) and the simulator was set sequentially to imitate climbing a ramp inclined on 0°, 2° and 4°. Kinematic data of the body were collected by a motion capture system. Kinetic data such as hand force and driving torque, were measured by instrumented wheels with incorporated six-axis force sensor. The intersegmental joint forces and moments were calculated from the obtained kinematic and kinetic data via inverse dynamics analysis procedure. Muscle forces were computed from the measured joint moments by using an optimization approach. Shoulder joint contact force, which indicates the joint surface loading, was computed as a synthetic vector of the intersegmental force for shoulder joint acquired from the inverse dynamics analysis and the compressive forces from muscles, tendons, ligaments and cartilages crossing the shoulder joint. It was observed that the decrease of the gear ratio causes increased cycle frequency and reduces the shoulder joint contact force. Result showed that the shoulder joint contact force during lever propulsion with a gear ratio 1/1.5 was up to 70 % lower than the shoulder joint contact force during handrim propulsion. The results from this study could be used in the design of new lever propulsion mechanisms that reduce the risks of secondary shoulder disorders and increase user's comfort.

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Section: Open Accessmentioning

confidence: 99%

“…A wheelchair simulator of wheelchair handrim propulsion was developed by the authors for their previous research [13]. It allowed simulation of wheelchairs with different geometry by changing the horizontal position of the seat and its height, distance between driving wheels, seat angle, and backrest angle.…”

Section: Wheelchair Simulatormentioning

confidence: 99%

Shoulder joint contact force during lever-propelled wheelchair propulsion

et al. 2015

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“…The most common problems of wheelchair users, who push on the handrim an average of 2000-3000 times a day, are shoulder, wrist, and hand injuries including carpal tunnel syndrome. For these reasons, studies of wheelchair propulsion have mainly addressed the physical load borne by wheelchair users, in addition to technical improvements, wheelchair configurations, and design optimization (Cooper, 1998; Engstrom, 2002;Sasaki et al, 2007bSasaki et al, , 2008. A study related to optimal wheelchair design that we performed, (analytical results of wheelchair propulsion using the manipulating force ellipsoid) based on human joint torque characteristics is described here.…”

Section: Application To Wheelchair Propulsionmentioning

confidence: 99%

“…Biomechanical analysis using a rigid link model and the musculoskeletal model is a more objective technique. It replaces electromyogram analysis, and has been applied for the estimation of joint forces and torques, muscular tensions, and energy consumption during the use of various devices such as wheelchairs and assistive carts (Sasaki et al, 2005(Sasaki et al, , 2008Miyawaki et al, 2000Miyawaki et al, , 2007. In this case both the simultaneous measurements of the external forces acting on a human body and the body movements are required for the analysis.…”

Section: Introductionmentioning

confidence: 99%

Higher Dimensional Spatial Expression of Upper Limb Manipulation Ability Based on Human Joint Torque Characteristics

Sasaki¹,

Iwami²,

Miyawaki³

et al. 2010

Robot Manipulators New Achievements

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“…This evaluation method, which is commonly used in the field of robotics, provides effective knowledge for evaluation of the manipulability of upper and lower limbs considering both the kinematics and dynamics of the system (Sasaki et al, 2008(Sasaki et al, , 2010. The manipulability of the upper and lower limbs in three-dimensional task space is expressed as an invisible six-dimensional polytope.…”

Section: Introductionmentioning

confidence: 99%