Matching Items (12)

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Design, Characterization, and Evaluation of a Dynamic Soft Robotic Prosthetic Socket Interface

Description

Prosthetic sockets are a static interface for dynamic residual limbs. As the user's activity level increases, the volume of the residual limb decreases by up to 11% and increases by as much as 7% after activity. Currently, volume fluctuation is

Prosthetic sockets are a static interface for dynamic residual limbs. As the user's activity level increases, the volume of the residual limb decreases by up to 11% and increases by as much as 7% after activity. Currently, volume fluctuation is addressed by adding/removing prosthetic socks to change the profile of the residual limb. However, this is time consuming. These painful/functional issues demand a prosthetic socket with an adjustable interface that can adapt to the user's needs. This thesis presents a prototype design for a dynamic soft robotic interface which addresses this need. The actuators are adjustable depending on the user's activity level, and their structure provides targeted compression to the soft tissue which helps to limit movement of the bone relative to the socket. The engineering process was used to create this design by defining system level requirements, exploring the design space, selecting a design, and then using testing/analysis to optimize that design. The final design for the soft robotic interface meets the applicable requirements, while other requirements for the electronics/controls will be completed as future work. Testing of the prototype demonstrated promising potential for the design with further refinement. Work on this project should be continued in future research/thesis projects in order to create a viable consumer product which can improve lower limb amputee's quality of life.

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Date Created
2018-05

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Design and Development of the Soft Robotic Back Orthosis

Description

Low back pain is a disorder which affects almost 80% of the American population at some time during their lifespan. Approximately, 90% of these episodes are resolved within six weeks to three months. As low back pain is usually a

Low back pain is a disorder which affects almost 80% of the American population at some time during their lifespan. Approximately, 90% of these episodes are resolved within six weeks to three months. As low back pain is usually a symptom of a medical condition; many cases cannot be given a definite diagnosis which renders the condition difficult to treat. The estimated annual cost for back pain treatment amounts to $50 billion, in the United States alone. Several devices have already been designed for low back pain assistance. However, in the majority, the main drawback appears to be the rigidity of the device, which limits flexibility and comfort. Soft pneumatic actuators have the potential to provide the appropriate applications for low back pain prior- and post-surgery rehabilitation purposes. In this work, the design and development of a soft robotic back orthotic device that has the capability to relieve back pain by assisting patients to fully achieve the upright position and stabilize the lumbosacral spine, is presented. Unlike conventional robotic assistive devices, this pneumatically actuated back orthosis provides dynamic support while being light weight, comfortable and cost affordable.

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Date Created
2017-05

Design and Fabrication of Soft Robotic Nautilus

Description

The field of soft robotics is a very quickly growing field that has yet to be fully explored or implemented in all of the possible applications. Soft robotics shows the greatest degree of possibility for mimicking biological systems effectively and

The field of soft robotics is a very quickly growing field that has yet to be fully explored or implemented in all of the possible applications. Soft robotics shows the greatest degree of possibility for mimicking biological systems effectively and accurately. This study seeks to set the groundwork for the development of a biomimetic nautilus using soft robotic methods. The study shows background research and discusses the methods used to develop a nautilus themed sub aquatic robot that uses a double bladder system and a pump to generate thrust for movement. The study shows how the unit would be fabricated and constructed. The study also explores why the second stage of the design failed and how it could potentially be fixed in future iterations.

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Date Created
2017-05

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Soft Robotic Haptic Interface With Variable Stiffness for Rehabilitation of Neurologically Impaired Hand Function

Description

The human hand comprises complex sensorimotor functions that can be impaired by neurological diseases and traumatic injuries. Effective rehabilitation can bring the impaired hand back to a functional state because of the plasticity of the central nervous system to relearn

The human hand comprises complex sensorimotor functions that can be impaired by neurological diseases and traumatic injuries. Effective rehabilitation can bring the impaired hand back to a functional state because of the plasticity of the central nervous system to relearn and remodel the lost synapses in the brain. Current rehabilitation therapies focus on strengthening motor skills, such as grasping, employ multiple objects of varying stiffness so that affected persons can experience a wide range of strength training. These devices have limited range of stiffness due to the rigid mechanisms employed in their variable stiffness actuators. This paper presents a novel soft robotic haptic device for neuromuscular rehabilitation of the hand, which is designed to offer adjustable stiffness and can be utilized in both clinical and home settings. The device eliminates the need for multiple objects by employing a pneumatic soft structure made with highly compliant materials that act as the actuator of the haptic interface. It is made with interchangeable sleeves that can be customized to include materials of varying stiffness to increase the upper limit of the stiffness range. The device is fabricated using existing 3D printing technologies, and polymer molding and casting techniques, thus keeping the cost low and throughput high. The haptic interface is linked to either an open-loop system that allows for an increased pressure during usage or closed-loop system that provides pressure regulation in accordance to the stiffness the user specifies. Preliminary evaluation is performed to characterize the effective controllable region of variance in stiffness. It was found that the region of controllable stiffness was between points 3 and 7, where the stiffness appeared to plateau with each increase in pressure. The two control systems are tested to derive relationships between internal pressure, grasping force exertion on the surface, and displacement using multiple probing points on the haptic device. Additional quantitative evaluation is performed with study participants and juxtaposed to a qualitative analysis to ensure adequate perception in compliance variance. The qualitative evaluation showed that greater than 60% of the trials resulted in the correct perception of stiffness in the haptic device.

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Created

Date Created
2017-12-20

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A Supernumerary Wearable Soft Robotic Arm for Task Execution Assistance

Description

This thesis proposes the concept of soft robotic supernumerary limbs to assist the wearer in the execution of tasks, whether it be to share loads or replace an assistant. These controllable extra arms are made using soft robotics to reduce

This thesis proposes the concept of soft robotic supernumerary limbs to assist the wearer in the execution of tasks, whether it be to share loads or replace an assistant. These controllable extra arms are made using soft robotics to reduce the weight and cost of the device, and are not limited in size and location to the user's arm as with exoskeletal devices. Soft robotics differ from traditional robotics in that they are made using soft materials such as silicone elastomers rather than hard materials such as metals or plastics. This thesis presents the design, fabrication, and testing of the arm, including the joints and the actuators to move them, as well as the design and fabrication of the human-body interface to unite man and machine. This prototype utilizes two types of pneumatically-driven actuators, pneumatic artificial muscles and fiber-reinforced actuators, to actuate the elbow and shoulder joints, respectively. The robotic limb is mounted at the waist on a backpack frame to avoid interfering with the wearer's biological arm. Through testing and evaluation, this prototype device proves the feasibility of soft supernumerary limbs, and opens up opportunities for further development into the field.

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Created

Date Created
2016-05

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Design of Soft Robotic Grippers for Dexterous Manipulation in the Tasks of Daily Living

Description

This honors thesis project aims to design and develop the ideal design for a soft robotic grasper used in combination with a robotic supernumerary limb design for impaired individuals (i.e. a wearable robotic limb that branches out of the body),

This honors thesis project aims to design and develop the ideal design for a soft robotic grasper used in combination with a robotic supernumerary limb design for impaired individuals (i.e. a wearable robotic limb that branches out of the body), to help accomplish the tasks of daily living. Observations of current grasper solutions for similar applications has led to a design that incorporates a soft, pneumatically controlled grasper which integrates with the existing limb. Computational models of the grasper design have been created which demonstrate the grasping capabilities of this proposal. Initial prototypes of this grasper approach have been fabricated for testing and analyses purposes to build a foundation for future implementation.

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Agent

Created

Date Created
2016-12

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User Intent Detection and Control of a Soft Poly-Limb

Description

This work presents the integration of user intent detection and control in the development of the fluid-driven, wearable, and continuum, Soft Poly-Limb (SPL). The SPL utilizes the numerous traits of soft robotics to enable a novel approach to provide safe

This work presents the integration of user intent detection and control in the development of the fluid-driven, wearable, and continuum, Soft Poly-Limb (SPL). The SPL utilizes the numerous traits of soft robotics to enable a novel approach to provide safe and compliant mobile manipulation assistance to healthy and impaired users. This wearable system equips the user with an additional limb made of soft materials that can be controlled to produce complex three-dimensional motion in space, like its biological counterparts with hydrostatic muscles. Similar to the elephant trunk, the SPL is able to manipulate objects using various end effectors, such as suction adhesion or a soft grasper, and can also wrap its entire length around objects for manipulation. User control of the limb is demonstrated using multiple user intent detection modalities. Further, the performance of the SPL studied by testing its capability to interact safely and closely around a user through a spatial mobility test. Finally, the limb’s ability to assist the user is explored through multitasking scenarios and pick and place tests with varying mounting locations of the arm around the user’s body. The results of these assessments demonstrate the SPL’s ability to safely interact with the user while exhibiting promising performance in assisting the user with a wide variety of tasks, in both work and general living scenarios.

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Created

Date Created
2018

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Indicators of Anticipated Walking Surface Transitions for Powered Prosthetic Control

Description

Human locomotion is an essential function that enables individuals to lead healthy, independent lives. One important feature of natural walking is the capacity to transition across varying surfaces, enabling an individual to traverse complex terrains while maintaining balance. There has

Human locomotion is an essential function that enables individuals to lead healthy, independent lives. One important feature of natural walking is the capacity to transition across varying surfaces, enabling an individual to traverse complex terrains while maintaining balance. There has been extensive work regarding improving prostheses' performance in changing walking conditions, but there is still a need to address the transition from rigid to compliant or dynamic surfaces, such as the transition from pavement to long grass or soft sand. This research aims to investigate the mechanisms involved such transitions and identify potential indicators of the anticipated change that can be applied to the control of a powered ankle prosthetic to reduce falls and improve stability in lower-limb amputees in a wider range of walking environments. A series of human subject experiments were conducted using the Variable Stiffness Treadmill (VST) to control walking surface compliance while gait kinematics and muscular activation data were collected from three healthy, nondisabled subjects. Specifically, the kinematics and electromyography (EMG) profiles of the gait cycles immediately preceding and following an expected change in surface compliance were compared to that of normal, rigid surface walking. While the results do not indicate statistical differences in the EMG profiles between the two modes of walking, the muscle activation appears to be qualitatively different from inspection of the data. Additionally, there were promising statistically significant changes in joint angles, especially in observed increases in hip flexion during the swing phases both before and during an expected change in surface. Decreases in ankle flexion immediately before heel strike on the perturbed leg were also observed to occur simultaneously with decreases in tibialis anterior (TA) muscle activation, which encourages additional research investigating potential changes in EMG profiles. Ultimately, more work should be done to make strong conclusions about potential indicators of walking surface transitions, but this research demonstrates the potential of EMG and kinematic data to be used in the control of a powered ankle prosthetic.

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Agent

Created

Date Created
2018

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Evaluation of a Soft Robotic Knee Exosuit for Assistance in Stair Ascent

Description

Muscular weakness is a common manifestation for Stroke survivors and for patients with Anterior Cruciate Ligament reconstruction leading to reduced functional independence, especially mobility. Several rigid orthotic devices are being designed to assist mobility. However, limitations in majority of these

Muscular weakness is a common manifestation for Stroke survivors and for patients with Anterior Cruciate Ligament reconstruction leading to reduced functional independence, especially mobility. Several rigid orthotic devices are being designed to assist mobility. However, limitations in majority of these devices are: 1) that they are constrained only to level walking applications, 2) are mostly bulky and rigid lacking user comfort. For these reasons, rehabilitation using soft-robotics can serve as a powerful modality in gait assistance and potentially accelerate functional recovery. The characteristics of soft robotic exosuit is that it’s more flexible, delivers high power to weight ratio, and conforms with the user’s body structure making it a suitable choice. This work explores the implementation of an existing soft robotic exosuit in assisting knee joint mechanism during stair ascent for patients with muscular weakness. The exosuit assists by compensating the lack of joint moment and minimizing the load on the affected limb. It consists of two I-cross-section soft pneumatic actuators encased within a sleeve along with insole sensor shoes and control electronics. The exosuit actuators were mechanically characterized at different angles, in accordance to knee flexion in stair gait, to enable the generation of the desired joint moments. A linear relation between the actuator stiffness and internal pressure as a function of the knee angle was obtained. Results from this characterization along with the insole sensor outputs were used to provide assistance to the knee joint. Analysis of stair gait with and without the exosuit ‘active’ was performed, using surface electromyography (sEMG) sensors, for two healthy participants at a slow walking speed. Preliminary user testing with the exosuit presented a promising 16% reduction in average muscular activity of Vastus Lateralis muscle and a 3.6% reduction on Gluteus Maximus muscle during the stance phase and unrestrained motion during the swing phase of ascent thereby demonstrating the applicability of the soft-inflatable exosuit in rehabilitation.

Contributors

Agent

Created

Date Created
2018

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The Design and Characterization of a Soft Haptic Interface for Rehabilitation of Impaired Hand Function

Description

The human hand comprises complex sensorimotor functions that can be impaired by neurological diseases and traumatic injuries. Effective rehabilitation can bring the impaired hand back to a functional state because of the plasticity of the central nervous system to relearn

The human hand comprises complex sensorimotor functions that can be impaired by neurological diseases and traumatic injuries. Effective rehabilitation can bring the impaired hand back to a functional state because of the plasticity of the central nervous system to relearn and remodel the lost synapses in the brain. Current rehabilitation therapies focus on strengthening motor skills, such as grasping, employ multiple objects of varying stiffness and devices that are bulky, costly, and have limited range of stiffness due to the rigid mechanisms employed in their variable stiffness actuators. This research project presents a portable cost-effective soft robotic haptic device with a broad stiffness range that is adjustable and can be utilized in both clinical and home settings. The device eliminates the need for multiple objects by employing a pneumatic soft structure made with highly compliant materials that act as the actuator as well as the structure of the haptic interface. It is made with interchangeable soft elastomeric sleeves that can be customized to include materials of varying stiffness to increase or decrease the stiffness range. The device is fabricated using existing 3D printing technologies, and polymer molding and casting techniques, thus keeping the cost low and throughput high. The haptic interface is linked to either an open-loop system that allows for an increased pressure during usage or closed-loop system that provides pressure regulation in accordance with the stiffness the user specifies. A preliminary evaluation is performed to characterize the effective controllable region of variance in stiffness. Results indicate that the region of controllable stiffness was in the center of the device, where the stiffness appeared to plateau with each increase in pressure. The two control systems are tested to derive relationships between internal pressure, grasping force exertion on the surface, and displacement using multiple probing points on the haptic device. Additional quantitative evaluation is performed with study participants and juxtaposed to a qualitative analysis to ensure adequate perception in compliance variance. Finally, a qualitative evaluation showed that greater than 60% of the trials resulted in the correct perception of stiffness in the haptic device.

Contributors

Agent

Created

Date Created
2018