A5067422881- Muscle activation and electromyography studies
- Prosthetics and Rehabilitation Robotics
- Diabetic Foot Ulcer Assessment and Management
- Space Exploration and Technology
- Balance, Gait, and Falls Prevention
- Advanced Sensor and Energy Harvesting Materials
- Spaceflight effects on biology
- Stroke Rehabilitation and Recovery
- Lower Extremity Biomechanics and Pathologies
- Mechanical Circulatory Support Devices
- Musculoskeletal pain and rehabilitation
- Cerebral Palsy and Movement Disorders
- Motor Control and Adaptation
- Human-Automation Interaction and Safety
- Ergonomics and Musculoskeletal Disorders
- Occupational Health and Performance
- Thermoregulation and physiological responses
- Total Knee Arthroplasty Outcomes
- Sports Performance and Training
- Infrared Thermography in Medicine
- Planetary Science and Exploration
- Neuroscience and Neural Engineering
- Cardiac pacing and defibrillation studies
- Technology Assessment and Management
- Analytical Chemistry and Sensors
VA Puget Sound Health Care System
2013-2025
University of Washington
2016-2025
United States Department of Veterans Affairs
2004-2024
University of California, Riverside
2022
Rehabilitation Research and Development Service
2005-2021
Veterans Health Administration
2012
Seattle University
2009
University of Puget Sound
2006
Pennsylvania State University
2003
Johnson Space Center
1992-1995
Much is known about human walking, but it not how walking used during typical activities. Since improving ability a key goal in many surgical, pharmacological, and physiotherapeutic interventions, understanding community mobility demands regarding the length of bouts, number sequential steps frequently performed, duration common nonwalking (rest) behavior seems prudent. This study documents gait daily living 10 nondisabled employed adults to define bout duration, step counts, rest periods...
The movement of the center mass (COM) during human walking has been hypothesized to follow a sinusoidal pattern in vertical and mediolateral directions. COM displacement shown increase with velocity, but little is known about COM. In our evaluation at several speeds, 10 normal subjects walked their self-selected speed then 0.7, 1.0, 1.2, 1.6 m/s random order. We calculated location from 15-segment, full-body kinematic model using segmental analysis. Mediolateral was 6.99 +/- 1.34 cm slowest...
Reports on the design of a biorobotic actuator. Biological requirements are developed from published reports in muscle physiology literature whose parameters extracted and applied form Hill model. Data several vertebrate species (rat, frog, cat, human) used to evaluate performance McKibben pneumatic The experimental results show force-length properties actuator muscle-like, but force-velocity not. hydraulic damper with fixed orifices, placed parallel actuator, is proposed improve...
The C-Leg (Otto Bock, Duderstadt, Germany) is a microprocessor-controlled prosthetic knee that may enhance amputee gait. This intrasubject randomized study compared the gait biomechanics of transfemoral amputees wearing with those common noncomputerized prosthesis, Mauch SNS (Ossur, Reykjavik, Iceland). After subjects had 3-month acclimation period each knee, typical biomechanical data were collected in laboratory. At controlled walking speed (CWS), peak swing phase knee-flexion angle...
The McKibben artificial muscle is a pneumatic actuator whose properties include very high force to weight ratio. This characteristic makes it attractive for wide range of applications such as mobile robots and prosthetic appliances the disabled. In this paper, we present model that includes nonlinear, Mooney–Rivlin mathematical description actuator’s internal bladder. Experimental results show provides improvement in ability predict output force. However, discrepancy between experiment,...
Biorobotic research seeks to develop new robotic technologies modeled after the performance of human and animal neuromuscular systems. The development one component a biorobotic system, an artificial muscle tendon, is reported here. device based on known static dynamic properties biological tendon that were extracted from literature used mathematically describe their force, length, velocity relationships. A flexible pneumatic actuator proposed as contractile element experimental results are...
Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed systematically study effect mechanics on gait, gain insight into fundamental design principles. varied single parameter in isolation, energy-storing spring prototype foot, controlled storage return (CESR) observed gait. Subjects walked CESR with three different springs. performed parallel...
Unilateral below-knee amputees develop abnormal gait characteristics that include bilateral asymmetries and an elevated metabolic cost relative to non-amputees. In addition, long-term prosthesis use has been linked increased prevalence of joint pain osteoarthritis in the intact leg knee. To improve amputee mobility, prosthetic feet utilize elastic energy storage return (ESAR) have designed, which perform important biomechanical functions such as providing body support forward propulsion....
Microprocessor-controlled prosthetic knees are claimed to improve gait efficiency in transfemoral (TF) amputees. This hypothesis was tested a prospective randomized crossover trial that compared the Mauch SNS knee and C-Leg microprocessor-controlled eight TF The subjects were given 3-month acclimation period each knee. Then, their net oxygen cost (mL/kg/m) measured while they walked overground at four speeds random order: 0.8 m/s, 1.0 1.3 self-selected walking speed (SSWS). caused small...
The McKibben artificial muscle is a pneumatic actuator whose properties include very high force to weight ratio. This characteristic makes it attractive for wide range of applications such as mobile robots and prosthetic appliances the disabled. Typical often require significant number repeated contractions extensions or cycles actuator. action leads fatigue failure actuator, yielding life span that shorter than its more common robotic counterparts electric motors cylinders. In this paper,...
This article studies the design of passive elastic elements to reduce actuator requirements for powered ankle prostheses. The challenge is achieve most typically nonlinear response with element so that active ankle-torque from can be small. main contribution this a cam-based lower-limb prosthesis such response. Results are presented show addition peak torque requirement substantially, by ∼74%. Moreover, experimental results demonstrate desired within 10%.