Design and Evaluation of Pediatric Gait Rehabilitation Robots

Gait therapy methodologies were studied and analyzed for their potential for pediatric patients. Using data from heel, metatarsal, and toe trajectories, a nominal gait trajectory was determined using Fourier transforms for each foot point. These average trajectories were used as a basis of evaluating each gait therapy mechanism. An existing gait therapy device (called ICARE) previously designed by researchers, including engineers at the University of Nebraska-Lincoln, was redesigned to accommodate pediatric patients. Unlike many existing designs, the pediatric ICARE did not over- or under-constrain the patient’s leg, allowing for repeated, comfortable, easily-adjusted gait motions. This design was assessed under clinical testing and deemed to be acceptable. A gait rehabilitation device was designed to interface with both pediatric and adult patients and more closely replicate the gait-like metatarsal trajectory compared to an elliptical machine. To accomplish this task, the nominal gait path was adjusted to accommodate for rotation about the toe, which generated a new trajectory that was tangent to itself at the midpoint of the stride. Using knowledge of the bio-mechanics of the foot, the gait path was analyzed for its applicability to the general population. Several trajectory-replication methods were evaluated, and the crank-slider mechanism was chosen for its superior performance and ability to mimic the gait path adequately. Adjustments were made to the gait path to further optimize its realization through the crank-slider mechanism. Two prototypes were constructed according to the slider-crank mechanism to replicate the gait path identified. The first prototype, while more accurately tracing the gait path, showed difficulty in power transmission and excessive cam forces. This prototype was ultimately rejected. The second prototype was significantly more robust. However, it lacked several key aspects of the original design that were important to matching the design goals. Ultimately, the second prototype was recommended for further work in gait-replication research. Advisor: Carl A. Nelso

Biomechanical Foot Guidance Linkage

A gait replication apparatus can include a scalable mechanical mechanism configured to replicate different gaits . The scalable mechanical mechanism can include , for example , a four - bar linkage , a pantograph , a cam / Scotch - yoke mechanism , and so forth . In some embodiments , the mechanical mechanism includes a beam rotating about an axis passing proximate to its center , with a foot pedal slidably coupled with the beam , and a timing chain / belt or cable pulley - pair coupled with the foot pedal and looped about the beam . A method can include decomposing a foot path defined by Cartesian coordinates into polar coordinates , and providing a mechanical support for a foot , where a first mechanism controls an angular position of the mechanical support with respect to a reference frame , and a second mechanism controls a radial distance of the mechanical support from the reference frame

DYNAMIC EVALUATION OF A PINNED ANCHORING SYSTEM FOR NEW YORK STATE’S TEMPORARY CONCRETE BARRIERS

Temporary concrete barrier (TCB) systems are utilized in many circumstances, including for placement adjacent to vertical dropoffs. Free-standing TCB systems are known to have relatively large deflections when impacted, which may be undesirable when dealing with limited space behind the barrier (as seen on a bridge deck) or limited lane width in front of the barrier system. In order to allow TCB systems to be used in space-restricted locations, a variety of TCB stiffening options have been tested, including beam stiffening and pinning the barriers to the pavement. These pavement-pinning procedures have been considered time-consuming and may pose undue risk to work-zone personnel who are anchoring the barrier on the traffic-side face. Thus, a means of reducing TCB deflections while reducing risk to workers was deemed necessary. The primary research objective was to evaluate the potential for pinning alternate barrier sections on the back-side toe of the New York State’s New Jersey-shape TCBs and evaluate the barrier system according to the Test Level 3 (TL-3) criteria set forth in MASH. The research study included one 2270P full-scale vehicle crash test with a Dodge Quad Cab pickup truck. Four 151⁄2-in. (394-mm) long, vertical steel pins were placed through holes on the back-side toe of alternating barrier sections and inserted into drilled holes within the rigid concrete surface. Following the successful redirection of the pickup truck, the safety performance of the pinned anchoring system was determined to be acceptable according to the TL-3 evaluation criteria specified in MASH using the 2270P vehicle. However, it should be noted that significant barrier deflections were observed during the crash test and may be greater than those desired for work areas with restricted space

Design and Evaluation of Pediatric Gait Rehabilitation Robots

Gait therapy methodologies were studied and analyzed for their potential for pediatric patients. Using data from heel, metatarsal, and toe trajectories, a nominal gait trajectory was determined using Fourier transforms for each foot point. These average trajectories were used as a basis of evaluating each gait therapy mechanism. An existing gait therapy device (called ICARE) previously designed by researchers, including engineers at the University of Nebraska-Lincoln, was redesigned to accommodate pediatric patients. Unlike many existing designs, the pediatric ICARE did not over- or under-constrain the patient’s leg, allowing for repeated, comfortable, easily-adjusted gait motions. This design was assessed under clinical testing and deemed to be acceptable. A gait rehabilitation device was designed to interface with both pediatric and adult patients and more closely replicate the gait-like metatarsal trajectory compared to an elliptical machine. To accomplish this task, the nominal gait path was adjusted to accommodate for rotation about the toe, which generated a new trajectory that was tangent to itself at the midpoint of the stride. Using knowledge of the bio-mechanics of the foot, the gait path was analyzed for its applicability to the general population. Several trajectory-replication methods were evaluated, and the crank-slider mechanism was chosen for its superior performance and ability to mimic the gait path adequately. Adjustments were made to the gait path to further optimize its realization through the crank-slider mechanism. Two prototypes were constructed according to the slider-crank mechanism to replicate the gait path identified. The first prototype, while more accurately tracing the gait path, showed difficulty in power transmission and excessive cam forces. This prototype was ultimately rejected. The second prototype was significantly more robust. However, it lacked several key aspects of the original design that were important to matching the design goals. Ultimately, the second prototype was recommended for further work in gait-replication research. Advisor: Carl A. Nelso

Zone of Intrusion for Permanent 9.1-degree Single Slope Concrete Barriers

Three WDOT 9.1-degree single-slope concrete barriers, with top heights of 36 in. (914 mm), 42 in. (1,067 mm), and 56 in. (1,422 mm) (Standard 14B32), were analyzed for Zone of Intrusion (ZOI)’ and working width using nonlinear finite element analysis (FEA). Tire-barrier friction, vehicle-barrier friction, barrier stiffness, mesh size, tire deflation, and suspension component failures were all found to have effects on simulation results. The zone of intrusion and working width were evaluated for each barrier under varying tire deflation and suspension failure conditions and determined to have a maximum value of 12.2 in. (310 mm) for the front fender and 9.4 in. (240 mm) for the rest of the vehicle. The working width for each barrier was determined to be 24 in. (610 mm). Advisor: John D. Rei

Design and evaluation of scalable pediatric gait rehabilitation robots

Gait therapy methodologies were studied and analyzed for their potential for pediatric patients. Using data from heel, metatarsal, and toe trajectories, a nominal gait trajectory was determined using Fourier transforms for each foot point. These average trajectories were used as a basis of evaluating each gait therapy mechanism. An existing gait therapy device (called ICARE) previously designed by researchers, including engineers at the University of Nebraska-Lincoln, was redesigned to accommodate pediatric patients. Unlike many existing designs, the pediatric ICARE did not over- or under-constrain the patient’s leg, allowing for repeated, comfortable, easily-adjusted gait motions. This design was assessed under clinical testing and deemed to be acceptable. A gait rehabilitation device was designed to interface with both pediatric and adult patients and more closely replicate the gait-like metatarsal trajectory compared to an elliptical machine. To accomplish this task, the nominal gait path was adjusted to accommodate for rotation about the toe, which generated a new trajectory that was tangent to itself at the midpoint of the stride. Using knowledge of the biomechanics of the foot, the gait path was analyzed for its applicability to the general population. Several trajectory-replication methods were evaluated, and the crank-slider mechanism was chosen for its superior performance and ability to mimic the gait path adequately. Adjustments were made to the gait path to further optimize its realization through the crank-slider mechanism. Two prototypes were constructed according to the slider-crank mechanism to replicate the gait path identified. The first prototype, while more accurately tracing the gait path, showed difficulty in power transmission and excessive cam forces. This prototype was ultimately rejected. The second prototype was significantly more robust. However, it lacked several key aspects of the original design that were important to matching the design goals. Ultimately, the second prototype was recommended for further work in gait-replication research

Biomechanical Foot Guidance Linkage

A gait replication apparatus can include a scalable mechanical mechanism configured to replicate different gaits . The scalable mechanical mechanism can include , for example , a four - bar linkage , a pantograph , a cam / Scotch - yoke mechanism , and so forth . In some embodiments , the mechanical mechanism includes a beam rotating about an axis passing proximate to its center , with a foot pedal slidably coupled with the beam , and a timing chain / belt or cable pulley - pair coupled with the foot pedal and looped about the beam . A method can include decomposing a foot path defined by Cartesian coordinates into polar coordinates , and providing a mechanical support for a foot , where a first mechanism controls an angular position of the mechanical support with respect to a reference frame , and a second mechanism controls a radial distance of the mechanical support from the reference frame

DYNAMIC EVALUATION OF A PINNED ANCHORING SYSTEM FOR NEW YORK STATE’S TEMPORARY CONCRETE BARRIERS

Temporary concrete barrier (TCB) systems are utilized in many circumstances, including for placement adjacent to vertical dropoffs. Free-standing TCB systems are known to have relatively large deflections when impacted, which may be undesirable when dealing with limited space behind the barrier (as seen on a bridge deck) or limited lane width in front of the barrier system. In order to allow TCB systems to be used in space-restricted locations, a variety of TCB stiffening options have been tested, including beam stiffening and pinning the barriers to the pavement. These pavement-pinning procedures have been considered time-consuming and may pose undue risk to work-zone personnel who are anchoring the barrier on the traffic-side face. Thus, a means of reducing TCB deflections while reducing risk to workers was deemed necessary. The primary research objective was to evaluate the potential for pinning alternate barrier sections on the back-side toe of the New York State’s New Jersey-shape TCBs and evaluate the barrier system according to the Test Level 3 (TL-3) criteria set forth in MASH. The research study included one 2270P full-scale vehicle crash test with a Dodge Quad Cab pickup truck. Four 151⁄2-in. (394-mm) long, vertical steel pins were placed through holes on the back-side toe of alternating barrier sections and inserted into drilled holes within the rigid concrete surface. Following the successful redirection of the pickup truck, the safety performance of the pinned anchoring system was determined to be acceptable according to the TL-3 evaluation criteria specified in MASH using the 2270P vehicle. However, it should be noted that significant barrier deflections were observed during the crash test and may be greater than those desired for work areas with restricted space

ASSISTIVE REHABILITATION ELLIPTICAL SYSTEM

An elliptical system is disclosed having a crank assembly configured to be adjusted in length to accommodate users having varying gaits. In some embodiments, the crank assembly includes a crank and an axle connection bracket that is slidably adjustable with respect to the crank. For example, the crank assembly can include a crank link having a longitudinal body, where the longitudinal body is connected to the crank at one end and includes a longitudinal slots slidably coupled with the axle connection bracket. The axle connection bracket is configured to slide through a plurality of positions along the longitudinal body. In some embodiments, the crank assembly further includes a screw for adjusting the axle connection bracket with respect to the crank, where the screw can cause the axle connection bracket to slide through one or more positions of the plurality of positions when the screw is turned